~..

Volume 3 Number 4 December 1995 ISSN 1012·9812

ENERGY AUDIT MOtltTORING ENERGY POWERINCENTIVE DEVELOPMENT

TRAINING AWARENESSSCHEMES OF ENERGYAND ITS AND INFORMAnON SYSTEM AND EFFICIENT AND THROUGHMODERtltSAnoN NORMS SYSTEM MAMAGEMENT AWARDS EQUIPMENT DEMONSTRAnON PUBUCAnoNS

\ ~ ~/

REDUCED ENERGY CONSUMPTION

REDUCED COST OFPRODUCTION

UNITED NATIONS CENTRE FOR HUMAN SETTLEMENTS (Habitat)

'1II,

JOURNAL OF THE

NETWORKof African countries on Local building

materials and technologies

United Nations Centre for Human Settlements (Habitat)

Nairobi, 1995

Rice husk incinerator

List uf cuntents

Foreword .

The aim of the network and ils journal

Energy efficiency in the production of building materials

Energy conservation for cost reduction in Indian cement industry - NCB's initiatives

Energy efficient method of portland slag cement grinding . . . . .

Plant audit and energy management .

Events . . . . . . . . . . . .

Publications review . . . . . . . . . . .

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... ii

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17

22

27

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THE AIM OF THE NETWORK AND ITS JOURNAL

ii

The Network of Afric,"1 Countries on Loc,~ BuildingMaterials and Technologies has the objective ofstrengthening loc,~ technological capacity throughfacilitating infonnation now. regional cooperation mll}transfer of appropriate technologies in low-cost andinnovative building materials sector in African countries.

"The Journal of the Network. currently publishe~

hhmnually, aims at providing ach,mnel for infonnation thatis available ,md could be used by professionals, technicians.researchers. scientists as well m-i policy and

CONTRIBUTIONS TO THE JOURNAL

This Journul welcomes information or articles on low-costinnovations in huihling-materials technology. lnfbrmationin the limn of technic,~ an~ policy papers. illustrations.news items mld ,mnouncements of events c,m he sent fromindividuals or institutions in the private or public sector,from witl1in ,"1~ outside the Afric,m region. Allcorrespondence on the Journal should be a~dressed to theChief. Building ,md Infrastructure Technology Section,Rese,rrch ,md Development Division, UNCHS (Habit.1t),P.O. Box 3003lJ. Nairobi Keny'L

The views expres1'ied in this Journal do not necessarilyretlect those of the United Nations. Mention of finn munesand commercial products do not imply the endorsement ofUNCHS (Hahitat). The reprinting of ,my of the materi,~ inthis publication is welcome, provided that the source ismentioned and one copy sent to UNCHS (Hahitat).

Natiom~ Network InstitutionsHousing and Architecture DepmtmentMinistry of Town Pl,mning ,md HousingYaounde. Cmneroon

Department of Civil EngineeringUniversity of Ad~is AbabaEthiopia

Building and Road Research Institute (BRRI)Kumasi UniversityGhana

Housing ,md Building Resemch Institute (HABRI)College of Architecture ,md EngineeringUniversity of Nairobi, Kenya

Lesotho Housing ,md L<mdDeVelopment CooperationM'L,eru, Lesotho

Department of Civil EngineeringThe PolytechnicUniversity of M:~awi, M:,lllWi

dechiion-maker:-;. It is a medium for infonnation exchmlge,md facilitator for acquiring suitable technologies andknow-how by needy countries.

Efforts ,rre made to compile. process ,md publish mticlesand technic;~ papers originating. m,tinly from the Africanregion. However. as deemed appropriate and subject toav,tilability. resemeh findings and technologicalinfonnation from countries outside the Afrk,Ul region arcalso included to stimulate interregional cooperation m; well.

Dep,rrtment of Architecture ,md Civil EngineeringUniversity ofM'~ta, M:~ta

School oflndustrial TechnologyUniversity of M:lUritiUS, Mauritius

Ministry of Loc,~ Government :md HousingWindbok, Nmnibia

Nigerian Building ,md Road Resemch Institute (NBRRI)Lagos, Nigeria

Faculty of EngineeringFourah Bay CollegeUniversity of Sieml LeoneFreetown, Sierra Leone

Centre Technique des Materiaux de Constructionde la Cermnique et du VerreCTMCCVTunis. Tunisia

Ministry of Lands, Housing and Urb,m DevelopmentKmnpala. UgtUlda

Building ResClrrch Unit (BRU)Dar-es-Sala..'UnUnited Republic ofT<mzania

Natiom~ Housing AuthorityLusaka, Zmnbia

Ministry of Public Construction ,md Natiom~ Housing·HarareZimbabwe

Editor-in-Chief:K,~yan Ray

Editor:Baris Dcr-Petrossian

FOREWORD

Economic development i.md hum:m settlements development. consist lmgely of harnessing increasing mnounts of energy forproductive purposes in general. and shelter construction in particular. This can occur either by increasing the amount of energyreSDurces - if availability or such resources is unrestricted -' or by making more efficient use of available energy resources.

In the building-materials sector, energy is consumed mainly for extracting raw materials, manufacturing of finished products andin trrmsportating building materials to the site. The relative mnount of energy used in eacb of these areas vary depending on localconditions. However, tbe highest energy consumption occurs in the production process of,building materials.

The building-materials industries as a whole. rely to a large extent on high temperature processes :md afe mnong the mostenergy-intensive industries. For exmnple, the cost of energy in the production ofcement or clay bricks/tiles accounts for 50 to 70per cent of the direct cost of manufacturing. It is. therefore, import:mt that the use ofenergy in the production process is optimizedso that the overall cnst of housing construction is reduced :md the polluting impact of the excessive use of fossil fuel is arrested.

Various studies have revealed that Immy building-materials industries. particularly in developing countriel-i. Ul-ie outdatedtechnologies which are ineftidenl in terms of use of energy. Eventhough the tal-ik of reducing use of energy. while maintaininghigh quality and qualllity of outputs. is raUler difticult. measures could he taken to monitor :md optimize the use of energy in IheprotJuclion processes. Ultimately. the most promising approach would he to increw,e the use of low energy-content materials andapply energy-efficient and low-pOlluting technologies in the construction. It is in ligbt of this situation that the Habitat Agendaadopted by the second United Nations Conference on HUlmm Settlements (Habitat II) has emplUl,ized the need for Governmentsand stakeholders "to encourage [md promote the application of low energy, environmentally-sound and safe m[mufacturingtechnologies in the building materials :md construction sector".

This issue of the JOlll'l1ul is devoted to energy efliciency in the production of building materials. It is hoped tbat the readers willlind the contents of this issue interesting [md useful to their work. The contribution of Mr. Baris Der-Petrossirm of UNCHS(Habitat)'s Reserrrch ,md Development Division in drafting, compiling ,mdediting the articlesinduded in this.lOlIr!/(Jlis t1umkfullyacknowledged.

Dr. Wally N'DowA:-;sislanl Secretary-General

UNCHS (Habitat)

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Mud-Slrnw building blocks are both low-cDst and low-eoergy building materials, courtesy Sean Sprague/Earth Scan

iit

ENERGY EFF~C~ENCV ~N THE PROfDUCT~ON

OF BU~lD~NG MATER~AlS*

INTRODUCTIONMost developing countries have realized the significance ofexpanding the capacity of domestic production of buildingmaterials and have adopted or are in the course of adoptingnecessary policies to that effect. However, trnnslating thesepolicies into reality will depend fIrst and foremost on theavailability of the basic resource inputs for the production of avariety ofbasic building materials. The main inputs required forthe production of building materials are:

(a) raw materials;

(b) labour;

(c) capital items such as machinery and tools; and

(d) energy.

All these inputs play vik'l! roles in the production process andinadequate supply ofany of them will jeopardize the success ofany enterprise producing building matert'l!s. Yet. there arecertain building materials -- such as cement, lime and burnt-claybricks -- lor which energy alone is an exceptionally crucialfactor of production - in fact, so crucial that these materials caneasily be classified as energy-intensive building materials. Forinstance, in the production of fIred-clay bricks, the energy inputis the only means of transforming tire properties of the rawmaterial (clay) into the desirable building brick which shouldpossess cert."Iin characteristics in terms of strength, durabilityand resiswnce to water absorption. Similarly, in the productionof lime and cement, energy is the only input which transformsthe limestone into a material with cement properties.

In most developing countries, energy-dependent buildingmaterials are the key materials in the construction sector.Portland cement is thesingle most strategic material and, almostinvariably, where there are near substitutes such as low-strengthbinders, they all tend to be energy-dependent. For the purposeof low-income housing, opportunities to expand the availabilityof walling materials beyond the range of cement-basedmaterials are often restricted to another energy-dependentbuilding material - fIred-clay bricks. RoofIng materials poseanother problem of high-cost and scarcity but. unlike wallingmaterials, the options are limited to a few energy-intensivematerials: aluminium sheets, galvanized-iron _sheets andasbestos-cement sheets. One material which can be explored toimprove the availability of roofIng materials to the low-incomepopulation is fIred-clay tiles - another energy-intensivematerial.

Energy is probably the single most cruck'l! factor required toimprove the production of building materials in developingcountries, yet it remains SC~Irce, prohibitive in cost or notavailable. The main reason for tbis setback is obvious. The sharp

increases in crude oil prices in the 1970s have since sustaineda devastating trend in the energy situation, with theoil-importing developing countries being the mostdisadvantaged. The negative cycle in cost and supply of crudeoil has had a similar effect on alternative forms of energy suchas coal, fIrewood and electricity. The cost of energy in theproduction of a typical energy-intensive building material suchas cement comprises 60 to 75 per cent of the directmanufacturing cost (I) - tbat is, if the source of energy is everavailable at all.

In recent times, attention has continuously focused on ways andmeans of improving the energy situation to enhance thebuilding-materials sector. Efforts in this direction are beingmade in both developing and industrialized countries, withoutstanding achievements from the latter. Finland, for example,with minimal invesunents in ventilation technology hasachieved about30 to 75 per cent savings in energy consumptionin the concrete industry. Hungary has achieved a 50 per centreduction in energy consumption in the brick industry byrenewing dryers and stoves and promoting efficiency in heatrecovery (2). A few energy-saving technologies have alsoemerged in India and elsewhere. Thus, there is sufficientevidence that the negative trend in the energy sector isreversible. The purpose of this article is, therefore, to wkeaccount of the useful innovations towards improvement of theenergy situation and, in particular, to stimulate research anddevelopment activities in an effort to ensure wide-scaleproduction of local-building materials for the low-incomepopulation. .

I. Ellergy COllsumptioll ill tile Buildillg-MaterialsSector

Energy sources in tbe production of building materials can beclassified as either primary sources - such as oil, coal. gas, olherfuels and electricity, or as secondary sources - consisting ofwaste-heat which is generated during the production process.

While both sources of energy are important in tire search forenergy-efficiency in building materials production, the primarysources of energy are fundamenk'l! to the energy crisis ~U1d,

perhaps, deserve more attention. There is a distinction betweenthennal energy resources, which are responsible for the mainenergy transformation process in the production cycle, vis-a-visenergy for electrical power to run macbines for ventilation,grinding of raw materials and similar functions.Thennal-energy consumption normally outweigbs that ofelectrical power. For instance, in cement manufacture, fuelconsumption accounts for about 75 to 90 percent of the totalprimary energy used in a plant while electrical power accountsfor the remaining 10 to 25 per cent(3). In some small-sclOe

By Baris Der-Pelrossilln, UNCHS (Habitat). This article has been produced based on in-house research conducted earlier.

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technologies for production of lime and fired-clay bricks,energy requirements could sometimes be accounted for only byfuel consumption in the firing process.

Comparison between various building materials in terms oftheir energy-consumption patterns should t.'lke intoconsideration variations between countries and even within onecounlry; consideration should also be given to variationsbetween production technologies for the same buildingmaterial. This is a very complex task and, in the absence ofcomprehensive universal data in this areas, an attempt has beenmade in t..ble I to provide an indication of relative energyconsumption for selected building materials in India.

Table I. Energy consumption in the manufacture ofbuilding materials in India

Classification of material Energy consumption inMJ/kg of material

I Burnt-clay tiles 3.00

IT Burnt-clay bricks 1.43

HoUow-concrete blocks 1.20

Sand-lime blocks 1.03

ill Reinforced concrete 2.00-8.00

Unreinforced concrete 1.20

Aerated concrete 2.89

IV Portland cement 6.70

Hydrated lime 4.21

Gypsum plaster 1.52

Calcined-clay pozzolana 1.39

V. Steel 26.00

Aluminium 144.00

VI Wood products 3.00

Saurce: Fog, M. H. and Nadkarni, K. L., reference No. I

The energy values given in table I can only be meaningful ifcomparisons are made between materials with similar functionsin construction. For inst.1fice, cement, lime and gypsum arecomparable within the limits to which they can be used inconstruction for identical purposes. This phenomenon isillustrated in tables 2 and 3, using walling materials and bindersas examples. These consumption values become even moremeaningful when translated into cost values relative to total costof production as indicated in table 4.

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Table 2. Energy consumption in materials for walling

Element Energy content of Isq.m in MJ

Wall made of bricks: 118.0kg 278.5hollow-clay bricks, cement: 2.5kg 10.018em x lOcIn x 30cm lime: 6.4 kg 57.621cI11 thick sand: 0.043m 314.2

360.3

Wall made of bricks: 73.lkg 172.5hollow-clay bricks, cement: 2.0kg 8.0Scm x 18em x 30cm lime: 5.2kg 46.813cm thick Sand: 0.035m3 11.5

238.8;

Wall made of bricks: 127.0kg 660.4solid-clay bricks. cement: 1.8kg 7.212cm x 16cm x 25cm lime: 4.5kg 40.515cm thick sand: 0.03m3 9.9

718.0

Wall made of bricks: 255.0kg 1326.0solid-clay bricks, cement: 4.4kg 17.612cm x 16cm x 25cm lime: 11.1 kg 99.930cm thick sand: 0.074m3 24.4

1467.9

Wall made of adobe, adobe: 800.0kg 1.540cm x IDem x 20cm cement: 1.6kg 6.443 cm thick lime: 4.2kg 37.8

sand: 0.028m3 9.4

55.1

Wall made of adobe, adobe: 400.0kg 0.7520cm x 40cm x 40cm cement: 1.6kg 6.423cm thick lime: 4.2kg 37.8

sand: 0.028m3 9.3

54.25

WnIl made of concrete cement: 52.4kg 209.6blocks, 20cm x 20cm lime: 7.0kg 71.1x 40cm 23cm thick sand: 0.159m3 52.5

stone: 0.107m3 35.3

368.5

Saurce: Rai, M. Energy Conservation in the Developmentand Production of Building Materials, reference No.7

Table 3. Energy consumption of selected binders (basis 1m3

wet mortar)

Composition of binder Energy requirementas percentage of 1:6cement-sand mortar

Cemeot sand (1:6) 100

Cement lime: sand (1:1:6) 135

Lime: burnt-clay pozzalana (1:2) 172

Lime: burnt-clay pozzolana: sand (1:1:1) 133

Lime: llyash or rice-husk ash (1:2) 94

Lime kiln reject flyash or rice-husk 25ash (1:2)

Saurce: Rai, M. Energy Conservation in the Developmentand production of Building Materials, reference No. 7

Table 4. Cost of energy relative to production cost ofselected materials

The extent to which the choice of technology determines theefficiency of energy utilization can be illustrated with thefollowing examples:

(a) Cement production

Cement production is basically a choice between rotary kilntechnology and vertical shaft kiln technology. The rotitry kilnis more popular, due to several technical advantages. However,on account of energy consumption alone, the shaft kiln is moreefficient-- as illustrated in table 5.

Table 5. Typical energy consumption patterns of cementmanutilcttrring processes in Europe (fossil fuel only)

Material

Cement

Lime

Gypsum products

Bricks and tile

Otller stroctuml

Clay products

Concrete blocks

Timber sawmills

Energy cost as percentage oftotal material cost

43.0 - 53.0

47.9 - 59.5

11.1 - 16.6

29.7 - 36.5

23.7

35.2

3.6 - 6.5

2.2 -4.1

Type of kiln Energy consUlnptionin kcaljkg of clinker

860

1300

790

750Shaft kitn

Rotwy kitn types

Dry (long kiln)

Wet (long kiln)

Dry (suspension pre-heater)

In a similar development in India, it was established that whilea vertical shaft kiln consumed around 750 kcaljkg of clinker. arowry kiln consumed up to 2000 kcal/kg of clinker. In additionto the adv,mtage of low-fuel consumption, the vertical shaftkilns are known to have operated efliciently on a variety ofsolidfuels, sometimes with an ash content as high as 50 per cent (5).Even within the rotary kiln technology. there 'tre variationsbetween tbe wet process 'md the dry process, witb implicationsfor energy-efficiency. For inst'mce, a wet process couldconsume 1400 kcaljkg of cement comp'tred to 750 kcaljkg ofcement energy consumption in the dry process - a difference ofabout 86 per cent (6).

SOllrce: Spence, R.J.S. Small-scale Production ofCementitious Materials, LT. Publications Ltd., London. 1980.

production technology: and

scale of production.

(a)

(b)

(b) Lime production

Fuel consumption in alternative technologies for production ofhydrated lime tends to show the importimce of cboice oftecbnology in achieving energy efliciency. Using thecm;e-study of the Federal Republic of Genmmy in table 6, anenergy saving ofabout 40 per cent is achieved wlten rotitry kiln

Table 6. Fuel consumption in lime production using different technologies

Another imporumt but often neglected component in energyconsumption in the building- materi'ds sector is in relation totnmsportation or distribution of the finished product forconstroction. Building materi'ds are produced solely forconstroction so that theirenergy consumption computations canonly be finalized at the point of use. In fact, there are somedeveloping cOlffitries where the cost of transporting buildingmateri,ds outweighs the actual cost of production. In Botswana,Honduras and Sudan, after 100 miles, the cost of tr,msportingcement is higher th'm the manufacturing cost(4).

II Prevailillg ellergy-illefficielltproductioll systems

Despite tlle high cost 'md sc,trcity of energy, there is aconsiderable degree of wastefulness in the use of energy in theproduction of building materials, especi,dly reg,lfding energy­dependent building materi'ds. To some extent, energy loss inthis context can be attributed to basic hUlmm error or negligencein the production process. However, a fundmnental reason forwastefulness in energy utilization can be attributed to tworelated t~lctors:

SOllrce: UNlDO - The building materi'ds industry indeveloping countries, ,m ,m,dytical appnrisal, sectond studiesseries No. 16 vol. I, Vienna 1985 p. 98.

Country Type of kiln Proportion of production cost Primnry energy consumptionMJjkg quicklime

Tmditional vertical kiln

Fedentl Republic of Genmmy Ring annuhtr kiln

Rotary kiln

35 4.760

22 4.865

20 6.715

India

Traditiomd kiln

Conventional

Improved shaft kiln (CBRI)

12.60

9.03

6.24

SOllrce: UNCHS (Habitat). Teehnic'tl note No. 12. 1987

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technology is adopted in place of a traditional vertical kiln. Asimilar lrend applies to India, where energy efficiency of theCBRl improved shaft kiln has been achieved through theprinciples of uniformity of heat distribution over the crosssection of the kiln plus the provision of a good draught system.In detail, the CBRl kiln is a tall cylindro-conical structureconstructed of masonry material with an internal lining offired-clay bricks. The effective height ofthis kiln for a 10 tonneper day capacity is 11m and the calcining zone maintains atemperature of 950°C to I 100°C (7).

(c) Fired-clay bricks

The theoretical energy requirement for firing clay bricks insmall-scale kilns is about 20 to 35 per cent of the actual energyconsumption in production practice. Thus, most existing brickproduction technologies are by definition energy-inefficient.Despite this lrend, large-scale kilns are more efficient in energyconsumption than traditional kilns as exemplified in table 7.

Since lransportation of bricks from the point of production tothe point of use accounts for a significant amount of energyconsumption, it could be argued that the scale of production isa crucial determinant of efficiency in energy utilization.Building materials, by their nature, tend to bave a low value-toweight ratio so that they are excessively costly to transport evenover short distances. This situation is worsened in mostdeveloping countries where the scarcity and prohibitive cost ofoil are rampant and where the infrastructure or' facilities fortransportation are under-developed. Large-scale productiontechnologies predetermine high-energy consumption fordistribution of building materials because a single plant oftenhas a wide catchment zone, sometimes an entire country.Large-scale brick industry is an example of prevailing error inchoice of scale of technology as far as energy-efficiency inlransportation is concerned.

Table 7. Energy consumption in brick-making technologies

III. ltmovationsfor energy-efficient building materialsproduction technologies

There are at least four ways in which the building materialssector can realize improvements in terms of energy-efficiency.These are:

(a) extensive use of those building materials whichcan be produced with hardly any expenditure on thermal energyor electrical power;

(b) innovative technologies to improve or minimizefuel consumption in energy-intensive building materialsproduction;

(c) innovations related to uSe of cheap and renewableforms of energy as fuel or electriCal power; and

(d) promotion of small-scale technologies tominimize energy consumption in transportation of materials.

Thc four Slrategies outlined above are interrelated rather thanindependent. Thus a comprehensive approach to the energycrisis may require the implementation of all four approachesconcurrently.

The following parts of this article show the specific merits ofeach.

(a) No-energy bl/ilding maceril/ls

In principle, building materials which can be produced withoutthe use of any type of thermal energy and electriCal powershould form the cornerstone of the building materials sector incountries facing scarcities and high cost of energy.Unfortunately, there are only a limited number of such buildingmaterials. Typical examples are unstabilized soil blocks,fibre-reinforced soil blocks, manually produced bamboowalling and thatch roofmg.

Technology Scale of production Labour required (man-hr Over-all energy consumpion(No. of bricks) for 1000 solid bricks) (MJ/1000 solid bricks)

Small-scale production, all 2,000 20 to 30 7,000 to 10,000manual methods, clamps,scoves, scotch kilns

Small-scale production, all 2,000 30 to 40 10,000 to 15,000manual methods, up draughtand down draught kilns

Medium-scale production, all 20,000 30 to 40 4,000manual methods, bull's kilns

Medium-SCale production, 30,000 30 to 35 3,000 to 3,500semi-mechanized method,Hoftmann on zig-zag kiln

Large-scale production, full 150,000 10 to 15 3,000 to 4,000mechanized tunnel kiln I

SOl/ree: UNCHS (Habitat), Technical Note No.12.

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(b) Innovative technologies to improve fuelconsumption in energy-intensive building materials

Some energy-intensive building materials are indispensable toconstruction so that any improvements in their supply and costshould depend on feasible innovations to optimize the energyconsumption patterns in the production process.

Fortnnately, recent innovations have proven that energyutilization in the production of materials such as cement, lime,concrete and fired-clay bricks can be optimized withconsiderable benefits in energy savings. Using Portland cementas an example, table 8 gives an indication of some interestinginnovations.

Another innovation regarding energy-savings in cementprodnction is the technology ofblended cements. The blendingof certain carbonaceous materials such as granulated slag,fly-ash and other pozzolanas with cement makes it possible toproduce more cement from the same amount ofclinker and thus

reduce the final consumption of energy per ton of cementproduced. Experiencehas shown that up to 20 per centofclinkercan bereplaced by fly-ash and up to 25 per cent by blast furnaceslag without changing the performance of blended cements incomparison to Portland cement for general application inconstruction. In somecoumnes, this mode ofproduction has ledto an estimate of20 to 40 per cent savings in fuel consumption.Further examples of innovations in production technologyrelated to energy savings for a variety of building materials aregiven in table 9. Fortunately, most of the materials identified inthis table are abundailtly available in most developingcountries; indeed, they exist as waste products which pose adisposal problem. One way to enhance the wide-scale use ofthese innovative technologies is to promote effective andeconomic strategies for collection and distribution of thesewaste materials.

(c) Innovations related to use ofcheap and renewablesources ofenergy for fuel and electrical power.

Plant type/location Energy savings Measure taken

A Energy con setYatiotl

Wet process

Long-dry process

Preheater-dry

Semi-dry process

Dry process

B l.QUlcrim' $Qec(fic enervy con mmntiOlI

Wet process (Canada)

Wet process (Canada)

Wet process (USA)

Wet process (Brazil)

Wet Process adding (USA)

Savings of 150 kcals/kg

Savings of512 toe/year, Preheating offuel oil by using clinker cooler wasteheat from heat exchanger inside thecooler.

Savings of 625 toe/year, Use of coalmine tailing as substitute processof fueloil

Savings of 625 toe/year

Savings of 14 kcals/kg, Addition of newkiln seal at discharge end to cut out airinfIltration.

IO per cent (from 1,416 kcals/kg to1,280 kcals/kg)

9 per cent (from 1,441 kcals/kg to 1,280kcals/kg)

17 per cent (from 1,876 kcals/kg to1.560 kcals/kg)

II percent (from 1,841 kcals/kg to1,637 kcals/kg)

15 per cent (from 1,617 kcals/kg to1,38I kcals/kg)

Adding a vent air recirculation systemtoclinker cooler thereby reducingdustwastage and increasing heatrecuperation.

Use of clinker cooler vent air as primaryair to hot air furnace.

Recirculating clinker cooler air.

Slurry thinner to lower slurry moistureto 1,280 kcals/kg) from 35.8 per cent to31.2 per cent with increase in clinkerproduction by 9 per cent.

Reduction in slurry moisture, new sealsand closing holes, new cooler grates,and fans, new chain system.

Changing clay component. modifyingchain system.

Slurry water reduction, lifters insulatingbricks, raw feed chemistry control, chainmaintenance, and cooler modification.

Source: Fog, M. H. and Nadkarni, K.L. reference No.1.

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It can be argued that the most important strategy to tackle theenergy situation relates to the availability and use of substitutesto coal, oil, gas and firewood. In the search for cheaperalternatives to conventional forms of energy, one should aimflfst and foremost at those options which are easily achievablewithin the resource capacities of developing countries ­preferably energy options related to waste materials. Forchoosing the energy sources, the criteria should thus initiallyignore disadvantages in rate of energy consumption using"new" forms ofenergy vis-a-vis conventional forms of energy.

On the basis of the above, one could summarize the innovationsworth promoting as follows:

(i) development of energy from bio-mass based onagricultural residues and in a form which could be transported,

Le., by pyrolytic conversion ofbio-mass into liquid and gaseousenergy or charcoal;

(ii) use of agricultural and industrial wastes such asrick husk, directly as forms of solid fuel;

(iii) recycling and/or incineration of municipal-solidwastes - glass, aluminium, paper, plastics, wood and rubber;

(iv) development of suitable forms of energy from thesun, ocean, wind and geo-thermal power for direct heating or .drying processes or for conversion into electrical power.

Table 9. Utilization of industrial and agricultural wastes for production of building materials in energy-saving technologies

Type Supply of material Mode of utilization Energy Saving (percentage)

I. Granulated blast Iron and steel Up to 45 per cent 35 to 40 per cent of energyfurnace slag industry additive to cement to produce consumption in manufacturing

blended cement of ordinary Portland cement

2. Air-cooled and same Substitute to conventional coarse 10 to 15 percent compared tofoamed blast aggregate. stone aggregate.

3. Fly-ash Thermal power plants using Up to 30 per cent additive to 25 to 30 per cent of energycoal cement to produce blended consumption in manufacture of

cement ordinary Portland cement.

4. Fly-ash same 20 to 40 per cent interground 25 to 30 per cent equivalent ofwith clay to produce fired-clay energy consumed in firing bricksbricks consumed'in firing bricks with

coal or wood

5. Colliery waste Coal washing plants 10 to 25 per cent In interground 20 to 25 per cent comparison towith clay to produce fired-clay normal energy requirementsbricks using coal

6. Mineral tailing Residues of iron, cooper, Constitutes 20 to 50 per cent of 15 to 30 per cent Compared tozinc, tin, lead, gold, silver raw materials for production of energy consumption in normal

frred-clay bricks, masonry production systemcement, cellular concrete andsand-lime bricks

7. Calcium carbonate Fertilizer, tannery, sugar, As raw material for lime 10 to 15 per cent Comparedsludge paper and acetylune manufacture production from traditional raw

industries materials

8. Bauxite waste Aluminium or bauxite 50 per cent additive inter-ground 5 to 10 per cent compared to(red mud) industry with clay in production of energy consumption in normal

fired-clay bricks production systems

9. Husks of rice, Yarious plant sources 10 to 25 per cent additive 15 to 25 per cent equivalent ofgroundnut, interground with clay and coal consumption in normalcoffee, maize coconut pithin production of production process

fired-clay bricks. The huskswhen incinerated into ashes canbe mixed with lime to producelow-strength binders of blendedwith ordinary Portland cement toproduce masonry cement.

Source: UNCHS (Habitat), Technical Note No. 12.

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(d) Promotioll ofsmall-scale productioll UllitS

This strategy is the only logical means of ensuring distributionof building materials to the ultimate point of use with minimaldemands on fuel for transportation. Fortunately, recentinnovations have made it possible for almost every buildingmaterial to fit into varying scales of production defying themonopoly of large-scale production systems which certainsectors such as the cement, steel and aluminium industries usedto enjoy. For instance, in some countries, the introduction ofmini steel plants utilizing scrap metal as raw material has led tonoticeable savings in energy consumption in the steel industry.

CONCLUSIONS

The indispensable role of energy as a factor ofproduction in thebuilding-materials sector is undermined by the crippling trendof its scarcity and high cost in most developing countries.However, as indicated in this article, there is proven know-howto deal with this negative situation. In fact, some of thetechnological options for energy-efficiency in buildingmaterials production are so simple and basic that it may not betoo difficult to put them into actual practice. What remains tobe done is to find an effective means of promoting the requisitetechnological innovations at the local level either throughtransfer ofknow-how from external sources or even technologytransfer within a given country. Normally, informationdissemination through written materials such as this article, isnot in itself an end to realizing practical achievements intechnology transfer or technology innovation. Nevertheless, the

eXIsting gap in information flow related to technologyinnovation in developing countries, makes the information inthis article note of relevance to overall development efforts ­hopefully it will serve as the framework for designing effectivefield implementation programme on this subject.

REFERENCES

I. Fog, M. H. and Nadkarni, K. L., Energy efficiency andfuel substitution in the cement industry, World Bank,Washington, 1983.

2. Economic Commission for Europe, Energy savings inthe production of building materials and in theconstroction process, seminar on modern buildingtechnologies, Poland, 1985.

3. Ibid, reference No. I

4. UNIDO, The building materials industry in developingcountries, sectoral studies series No. 16, VoU Vienna,1985.

5. Spence, R. J. S., Small-scale production ofcementitiousmaterials, LT. Publications Ltd., London, 1980.

6. Ibid, reference No. I.

7. Rai, M., Energy conservation in the development andproduction of building materials, proceedings of theInternational Workshop on Energy Conservation inBuilding, C.B.R.I. Roorkee, India, 1984.

7

Bibliography

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Bessey, G. E., "Production and use oflime in developingcoulllries", Overseas Building NOle, No. 161, BuildiugResearch Establishment, Garston, U.K.. 1975

Boynlon, R. S., "Chemistry and Technology ofLime andLimestone", Interscience, New York, 1966.

Bryant, B. S., "Corrugated roofing panels fromagricultural residues", Appropriate Technology, 4(4),26-29,1978.

Cook, D. J.. "Using rice Ill/skfar making amelll-likematerials" Appropriate Technology 6(4), 9-11,1980.

DUlla, D. K., and others "Vertical shaft kiln (VSK)technology for mini/liny cement plant", Proceedings,Seminar on Energy Conservation process industries,July 1-2, Instilotion of Engineers, Roorkee, India, pp.11-7,1985.

Fog, M. H. and Nadkerni K. L.. Energy efficiency andfuel substitution in the cemelll industry, World Bimk,Washington D.C.. 1983.

Haseltime, B. A.. "Comparison of energy requirementsfor building materials and structures", The StrocturalEngineer, 53(9), 537,1975.

King, G. S., "Gypsum products and their applications inthe Australian building industry", Symposium on NewBuilding Materials Components, Baghdad, 1979.

Lea, F. M.. The Chemistry ofCement and Concrete, 3rdedition, Edward Arnold (Publishers) Limited, London,1970.

Matha, P. K., "Energy resources allu the environmellt:A review of the U.S. cemellt industry", World CementTechnology, 1979.

Parry, J. P. M., Brickmaking in Developing COl/lllries,Building Research Establishment, 1979.

Past.lIa, A. L., "The compact cement plant", WorldCement Technology, 9(4),121-127,1978

Prrumd, B., Shllilna. and others, "Swdies on electricalgasification of bio-mass at atmospheric pressure",Proceedings, Seminar on Energy Conservation inProcess Industries, 1-2July, The Institution ofEngineers(India) Roorkee, 1985.

Rrti, Mohan, "Energy saving in the manufacture ofnewbuilding materials", C.I.B. Journal vol. IV 15-19August, Stockholm, 1983.

Rrti, Mohan. "Energy conservation in the developmentand production of building materials", Proceedings,International Workshop on Energy Conservation inBuilding, 2-7 April, C.B.R.I.. Roorkee, India, pp.106-107,1984.

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Ridge, M. J., "Chemical gypsam", Third NationalChemical Engineering Conference, Instilution ofEngineers, Australia, 1975.

Saravia, R. and Lesioo Graciela, PersonalCommwzicatioll, Departamelllo, Deciennia, Exactw:i DeLa Universidad National de Salta, 1985. Buenos Aires177, Salta, Argentina

Spence, R. J. S.. A Study of the use of soil cemelll inbuilding, Report BR2, National Council for ScientificResearch, Lusaka, 1970.

Spence, R. J. S., Small-scale production of cementmaterials, Intennediate Technology Publications,London, 1985.

United Nations, Use of agricultural and industrialwastes in low-cost construction, ST/ESA/51/, pp 17(based on a seminar on 9-13 July 1974 at the Universityof Puerto Rico), 1974.

United Nations Economic Commission for Europe,"Energy savings in the production ofbuilding materialsill the construction process", Seminar on modembuilding technologies Warsaw, Poland October 1985.

UNIDO, Developmelll of appropriate technology forsmall-scale production of portland cement illless-developed countries and regions I Report based onconsullancy hy H. C. Block, UNIDO/10048, 1976.

UNIDO, The building materials industry in developingcOlmtries un anaLytical appraisal, sectoral studies seriesNo. 16 vol. I Vienm~ 1985.

UNCHS (R~bital), The use of selected indigenousbuilding materials with potentialfor wide application indeveloping cOllllllies, Nairobi, 1985.

UNCHS (habitHl), Energyfor Building, 199 I

UNCHS (Habit.~t), Energy efficiency in housingconstruction and domestic use in developing countries,1991.

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UNCHS (HahitHl), Vertical-shoji lime-kiln technology,IYY3.

ENEftiGY CONSElAVIAT~Ou~ fOfti COSTRElDllJCT~ON ~N ~NlD~AN CEMENT~NlDlJJSTRV~ NC[8~S n\]~T~AT~VES*

SYNOPSIS

The price of energy is a major component of the cost of cementprodnction, being as high as 60 per cent in some of the cementplants. In today's context of energy shortages and its risingprices, energy conservation has assnmed high priority inreducing production costs. The paper discusses the initiativesInken by NCB towards energy conservation and cost reductionin cement plants which include energy audit studies with thehelp of Mobile Energy Diagnostic Unit (MEDU), encouraginguse of incentive schemes, energy monitoring, power systemmanagement and motivating competitive improvements. Thepaper also highlights the salient features of MEDU which hasproved to be an effective tool for quick on the spot assessmentof energy-use pattern with the help of on-board computerprocess and electrical parameters and brings out some of thecase-studies carried out by NCB which has resulted in savingoff energy and reduction in the cost of cement production.

l. INTRODUCTION

During the last few years, there has been an increase in cost ofproduction as the prices of various forms ofenergy viz. thermaland electrical, which constitute a major component of cost ofcement production. This coupled with acute shortage of powerand reasonable quality fuels has compelled decision-makers inthe induslly to examine and find new ways and means forenergy conservation by minimizing energy wastage andachieving cost reduction in cement manufacture.

Cement Induslly in India has followed the principle ofco-existence by old and new cement plants and is in a uniquesituation wherein more and more large capacity plants, havebeen installed. These plants use dry process with preheaters andprecalcinators, but the old wet and semi-dry process plants aswell as small vertical shaft kiln plants are also existingsimultaneously playing their complementary roles in meetingthe counlly's demand for cement. The induslly has been apt toadopt technological developments and upgradings and most ofthe new ins~1.llations are coming up with energy efficientsystems and equipment. The problem of high ash and variablequality of coals, inconsistent power supply, low grade rawmaterials, harder to grind raw materials and coaIs have becomepart of nonnal operations in cement plants and results in highenergy consumption. Comprehensive approach is necessary toreduce the energy consumption.

*By J. P. Saxena, Ashwani Pahuja, Pradeep Kumar, National Councilfor Cement and building materials. New Delhi. This paper waspre.<;cnted to the third National CounL"i1 for Cement and BuildingMaterials (NCB) International Seminar on Cement and BuildingMaterials. held in January 1991 in New Delhi, India.

2. NCB'S INITIATIVES FOR ENERGYCONSERV ATION AND COST REDUCTION

Keeping in mind the various problems of the cement industry,NCB has Inken some initiative to reduce the energyconsumption levels (Figure 1). These include both short-termand long-term measures and some of these are discussed below.

2.1 Energy

Energy audit has emerged as an important tool foridentification, analysis, implementation ofenergy conservationmeasures and energy management. The importance of energyaudit studies was realized in early 80's when NCB incollaboration with Bureau oflndustrial Costs and Prices (BICP)made a survey of 46 cement plants in the country identifyingthe status of energy consumption levels, potential areas forenergy saving and recommendations for short, medium andlong-term measures. Subsequently the Advisory Board onEnergy (ABE) commissioned NCB to carry out dellliled energyaudit of six representative cement plants. NCB has since thencompleted 22 more energy audit studies in cement plants underits own R&D programme as well as studies sponsored by theindustry.

Energy audit studies has shown that 'prevention of false airinfiltration' (Figure 2) has the maximum impact on the energysavings hy operational control in plants. This factor alone hasbeen identified to have about 64 per cent of the to~1.l potentialthermal and about 35 per cent of the total potential electricalenergy cost savings in the plants studied. Process optimization,reducing the preheater exit gas temperature and waste heatutilization are other important areas of thermal energy savings(Figure 3). Reducing the free running of machines andunderloading of motors has emerged as one of the mostimportant factors in saving the electrical energy cost. Otherfactors of saving electrical energy costs as found out from NCBstudies are power factor improvement and retrolitting ofenergyefficient systems.

2.2 Mobile Energy Diagnostic Unit (MEDU)

NCB has taken initiative in modernizing the techniques forenergy audit to serve the needs of the industry. NCB's MEDU,a unique facility not only in the cement industry but in thecounlly, is equipped with latest and sophisticated facilities forfaster and accurate energy audit studies with various hardwareand software capabilities. The MEDU carries out energy daulanalysis at site including preparation ofaction plans, calculationof specitic energy consumption in each section, Utrget settingand monitoring, calculation of power factor and load factor ofthe plant, identification of locations of leakages ofcompressedair tmd the heat balance of kiln circuit (figure 4).

----_._--------------------=9

The instrument facilities in the MEDU measure parameterssuch as temperature; radiated heat from surfaces; 02, CO2 andCO quantity in gases; ambient humidity; gas velocity; leaks inhigh pressure lines; voltage, curren~ kW, kVA, power factorand luminous intensity etc. Apart from the above instrumentsfor insL.'1Iltaneous value measurement, continuous monitoringand recording facilities are available with the microprocessor­based equipment. The on-board computer is equipped withnecessary system and application software for real-time datalogging and quick datn analysis at site.

2.3 Incentive Schemes

NCB has been a prime actor in motivating the plants to takeright steps in energy conservation. Based on thetechno-economic feasibility of the energy efficient schemesthrough energy audits, some of the cement plants have aIrendyavailed the benefit of the incentive schemes from the financialinstitutions for energy audit and have secured loans forinstnUation of energy efficient equipment. These initiativeshnve brought oUl encouraging results.

2.4 Monitoring Energy Use

Having realized the need for monitoring energy use, NCB hasbrought out Guide Norms for Cement Plant Operations which

provide norms for energy usage in various sections of the plant,besides the operational norms. The norms have been in use incement plants extensively for evaluating the performance of agiven section and identifying the areas of improvement.

NCB jointly with DCCr is monitoring the energy use datn andhas alrendy analyzed the data of 80 cement plants for the year1988-89. The analysis made by NCB has brought out thespecific energy consumption levels of the industry, process andat the regional level; stntus ofenergy consumption levels in eachsection for dry and wet process plants; comparison of theselevels with NCB operational guide norms; effectofcoal qualityon the specific energy consumption in the plant and energy costtrends, process and at the regionalleveI.

Based on the analysis, NCB has also identified plants perlJliningto different processes for delJliled energy audit studies whereeither thermal or electrical energy consumption or both havebeen found to be on the higher side,

2.5 Energy ltiformation System

NCB studies of various cement plants reveal that systematicrecording of the data does not exist and there is a need fordeveloping comprehensive data-base keeping in view theultimate objectives. The dak~-base thus created would be

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Figure I. NCB's initiatives for energy conservation and cost reduction

10

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helpful for individual units as well as for inter-finn comparisonand identifying the real problem are:L<. Keeping the ahove inview NCB is currently engaged in developing an appropriatecomputerized energy information system for the Indian CementIndustry. Such an infonnation system shall greatly help inidentifying thrustare1L'. making right decisions at various levels:U1d fonnulation of policy guidelines.

2.6 Power System Managemellt

NCB 1m, developed a comprehensive system for m:U1agementof power in the cement plmlls (Figure 5) which includes asoltware for improvementofload factor through optimized loadscheduling thus maximizing the use of availahle grid powerfrom the electricity hmrrd 1U1d captive power installed in thepI1U1t. Various input' to the softMrre include grid and captivepower awnlability, power tariff. quality of power. KW load oneach equipment in the plant and other operational aspects. Theoutput from the softw1rre includes running schedule of eachmachine at any hour during the day. The software assists in

improvement in load factor, reduction in monthly maximumdemand, improvement in overall energy efficiency 1U1d betterproduction planning.

2.7 Motivation/or Competitive Improvemellt inEnergy Peiformance

NCB realized the need for creating awareness and motivationin cement industry for competitive improvement in energyperfonnance :md instituted National Award for EnergyEfficiency in Indian Cement Industry in 1986-87 to be givenaway annually in recognition to the efforts for improving energyperformance. The energy award has generated luts of interestand created motivation for energy conservation which isreflected from the analysis of da~~ of the 20 plants whichparticipated for energy award in all the three years from1987-88 to 1989-90.1t is seen that in case of dry process plantsin the year 1989-911 as compared to 1987-88, the reduction inspecific thennal energy consumption has been 2.4 per cent andin specinc electric1d energy consumption 7.5 per cent while in

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Figllfc 5. Module for power system management

14

case of wet process plants the specific thermal energyconsumption hl" decreased by 3.1 per cent with margimdreduction in specific electricld energy consumption (Figure 6).It is noted that the improvements in the performance of theseplmlts have come as a result of operation:u con~ol rmdoptimization efforts. retro-titting ofenergy efficlenteqmpment,tixation of targets, upgradation of process controlinstrumentation mId Immpower training.

NCB INITIATIV~~S- IMPACT ANDACHIEVEMENTS

The various steps taken In energy conservation such as energyauditing, monitoring the use ofenergy, creating an infonnationbase through energy infonnation system, a systematic powersystem management and motivation through National Awardfor Energy Efficiency in Cement Industry have created aheldthy structure for energy conservation efforts in the IndilInCement Industry,

The tindings from the studies have been revealing andindicating substantial savings of money through both thennal

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I§I SAVINGS IN ELECTRICAL ENERGY

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Figure 7. Energy lInd cost of savings by NCB energy audit studies in a 80D.OUO ton per year capacity plant

15

as well '" electrical energy savings. The potential ,mnualsavings in the v,trious plrmts studied nUlged from Rs I millionto Rs 19.2 million in dry process pl,mls and Rs 3.3 million toRs 6.3 million in wet process plrmts (table I).

In a specific case of a large capacity ofdry process cement plant(800,000 tonne/year), suggestions made by NCB wereimplemented by the plant which resulted in saving 8.5 kWh/tof cement of electric,O energy 'Uld 27 Kca/kg clinker of thenmOenergy during the year 1989-90. The totrO saving of energy costamounted to Rs 8.6 million that ye,U' (ligure 7). These result,were achieved through implementation of various suggestionsmade by NCB in different areas such as:

(i) NCB studies indicated false air infiltration in rawmill circuit up t022 per cent. Plugging ofleakages,maiataining optimum feed size, frequentregradation of grinding media, installation of slippower recovery system for raw mill vent fanresulted in overall reduction of about 2 kWh/tclinker.

(ii) Heat 'Uld mf." b,Oance of kiln circuit indicated 20per cemlrOse air in prebeater string ,md 15 per centf,Ose ,urin PC string. Plugging tbese leakages to themaximum extent and bringing down PC string exitgas temperature through making changes in rawme,O 'Uld reducing cmO tiring in PC string resultedin a reduction of heat consumption by 2.6 per cent.

Plugging of leakages and installation ofslip powerrecovery system for PH fan resulted in a saving of2.5 kWll/lof clinker.

(iii) A signiticfmt reduction of electricfO energy w,,,achieved in cement mill 'Uld packing section byproper selection ,md frequent regmdation ofgrinding media, prevention of leakages incompressed air lines. These efforts achieved asaving of 4 kWh/tof cement in this section.

(iv) Improvement of power factor resulted in reductionof eleclrical JOSHes .md maximum demand from18560 KVA in 1988-89 to 16240 KVA in 1989-90.

CONCLUSIONIn view of the complex situation, dIe Indian Cement Industry iscontronted with various shortrlges 'Uld poor qU[Oity inputs, it isimportant to increase awareness for energy conservation. Theright steps towards this direction would be effective monitoring,better operational control ;:md introspection of energy savingopportunities dlroUgh energy audit. This woulO enable the pl,mtm,magement to prioritize the vmious opportunities. Theexperience has shown that subsumtial cost savings can beachieved if tbe energy conservation eflllrts are rightlyimplemented.

ACKNOWLEDl;EMENTThe authors bave Ireely dmwn upon completed R&Dwork/status reports of NCB and some of the unpublished workin NCB. This paper is being published with the pennission ofDirector GenenO, NCB.

Tahle 1. Expected cost savings due to identitied potenti,Os for energy saving

Potential Saving in Energy

Process Plant Capacity (tpd) ThenmO (Kcal/kg c1.) Eleetric,O (kWh/t Potential Annualcement) Savings (R,. million)

Dry 4800 35.3 4.9 11.3

" 3000 5.8* 3.1* 3.894

" 2500 62 1.8 11.3

" 1800** 62.4 2.3 6.658

" 1500** 63.8 7.0 6.94

" 1800 211 18 19.25

" 1200 126.9 6.3 4.588

" 600 113 12 4.26

" 600 152 9.0 7.79

" 300 97.9 14.8 3.802

" 300** 71 0.5 1.078

Wet 1800 38 0.8 3.3113

" 1200 14~.5 1.9 6.27

" kWh/t Clinker** Energy audit studies hy Mohile Energy Diagnostic Unit (MEDU)

ENERGV EFF~C~ENT METHOD OF[PORTLAND SLAG CEMENT G[FUND~NG1d(

i

SYNOPSIS

New developments in grinding technology offer possibilities ofenergy optimization in cement grinding, particularly in case ofportland-slag cement-production, by proper system design.

Traditionally in most of the plants, portland-slag cement hasbeen manufactured by the so called .. combined grindingprocess" in which granulated slag and clinker are groundtogether. However, keeping in view the high quality standardrequirements ofthe consumers and greater emphasis on optimalenergy utilization, a system design for the so called "separategrinding process" was developed utilizing high pressuregrinding rolls with high efficiency separator for fmish grindingof sh~g and a combination of high pressure for grinding ofclinker and mixing of these two powdery material in acontinuous mixer to produce desired product quality.

1.0 INTRODUCTION

Recent innovations in grinding technology, particularly, withregard to development of High Pressure Grinding Rolls(HPGR) in close circuit with High Efficiency Separator (HES)offer potential for electrical energy saving in cement grinding.Tests conducted in sume of the industrial installations haveshown 20 to 50 per cent saving in electrical energy in case ofcement grinding using HPGR in close circuit with HEScompared to that in a close circuit ball mill system. At the sametime, industrial experience has shown that the modem energyefficient method using HPGR and HES influence thecharacteristics of cement in terms of particle size distributionand water demand of cement which affect the properties ofmortar and concrete. Cement properties are also influenced bygrinding conditions e.g. materials temperature, specific surfaceand grain size distribution of the ground material.

These conditions become more complex while designing asystem for grinding composite cement e.g. portland sh~g cement(PSC) where the grinding characteristics e.g. grindability,fragmentation characteristic etc. of the 3 components - clinker,gypsum and slag differ significantly from each other, Further,the product quality assurance has to be ensured also to meet thedemands of the consumer and be in conformity with thestandards and specifications.

In view ofthe energy saving potential, application ofHPGR andHES for grinding of PSC was made while preparing the systemdesign of a new 280 tonnes/hour PSC production unit underinstallation.

**N,". P. Verma. Holtec Engineers Private Limited. New Delhi. India.This paperwns presented to the third Nationnl Council for Cement andBuilding Materials (NCB) International Seminar on Cement andBuilding Materials, held in January 1991 in New Delhi, India

2.11 LABORATORY-SCALE INVESTIGATION

Laboratory-scale investigations were carried out to study theinfluence of proportion of slag in PSC, grindability andinfluence of specific surface on the overiill power requirementand influence of specific surface of clinker and slag on theproperties ofPSC.

Based on the technological considerations as indicated by thetest results, it was decided to grind clinker and slag to specificsurfaces 4200 sq. cmlg (Blaine) and 3400 sq. cmlg (Blaine)respectively.

3.0 SELECTION OF GRINDIN(; SYSTEM

Traditionally, production of PSC has been carried out in Indiaby the so called "combined grinding process" in which clinker,granulated blast furnace slag and gypsum are ground togetherin a close circuit ball mill. Due to difference in grindingcharacteristics of clinker and slag, this process poses thefollowing problems:

• Optimization of mill grinding media charge is difficult;

• Optimization of grinding fineness of clinker and slag isdifficult and often in order to achieve desired particle sizeof slag, clinker is overground causing sub-optimalutilization of energy.

On the other hand, the so called "separate grinding process" inwhich clinker mixed with gypsum and slag are groundseparately and then mixed together in a pre-determinedproportion in a mechanical mixer offers the followingadvantages:

• Better control of fineness of individual components ofPSC;

• Optimum energy utilization for clinker and slag grinding;'

• Optimum utilization of slag.Therefore, in view of the potential of energy saving andflexibility in quality conlrol, a separate grinding process wasadopted for clinker - gypsum mixture and slag grindinginstallations of 140 tonnes per hour capacity each for a cementplantunderconslruction.

-1.0 SYSTEM DESCHII'T!ON

Flow diagrams shown in Figures I, 2 and 3 depict the basicprinciple of grinding clinker and slag and mixing groundmaterials respectively.

4.1 Clinker grinding

Two identical HPGRs are used to pre-grind clinker and gypsummixture in requisite per centage. The sh~b produced from HPGRis conveyed to HES equipped with de-agglomerator. Fineproduct having specific surface around 2500 sq. cmlg (Blaine)is conveyed to an open circuit ball mill for finish grinding to

17

specific surface 4200 sq. cm/g (Blaine); the coarse fractionbeing fed back to tbe HPGR. Finish ground clinker is conveyedto silo.

4.2 Slag grinding

Two identical HPGRs are used for finish grinding of slag.HPGRs are operated in close circuit witb individual HES. Slabdischarged from HPGR is conveyed to HES. Though a'de-agglomerator is not provided in the HES at this slage,provision in layout has been kept so that it may be installed infuture, if required. Finish ground slag having 3400 sq.cm/g(Blaine) is conveyed to another silo,

4,] PSC production

A continuous paddle mixer is used to homogeneously mixground clinker and gypsum mixture and ground slag inpredetermined proportion to produce PSC, The homogenizingefficiency in terms of variation of slag/gypsum content in PSChas been guaranteed as ± 2 per cent at a confidence level of 95per cent in spot smnples drawn at mixer outlet

5.0 ELECTRICAL POWER REQUIREMENT

Based on the above system and for the aVlulable clinker andslag, equipment to be supplied have the specific powerconsumption guarantees as given in Table 1.

Table I. Specific energy consumption

Material Equipment Specific powerconsumption.KWH/tofground material

Clinker & HPGR, HES, Ball Mill and 54.2Gypsum Auxiliaries

HPGRalone 7.1

Ball Mill alone 38.1

Slag HPGR, HES and 30.3Auxiliaries

HPGRalone 22,2

It is thus seen that power consumption in the system adoptedabove would be of the order of 43 - 44 kWh/t PSC.

18

For the conventional combined grinding system, however,based on the laboratory tests, the specific power requirement atball mill shaft for grinding clinker mixed with slag wasestimated at 55-60 kWh/t of material ground to 3500 to 4000sq. cm/g (Blaine).

Therefore, energy saving to the extent ofl2 to 16 kWh/t ofPSCis foreseen by adopting the proposed grinding system.

6.0 INVESTMENT

In the above example, a study of relative invesbnent costs ofdifferent systems revealed the following;

• Conventional combined grinding100 per cent

• Using HPGR in Hybrid mode (i.e.HPGR as a pre-crusher grinder)109 per cent

Using HPGR in finish/semi-finish mode 90 per cent.

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21

PLANT AUDIT AND ENERGYMANAGEMENT***

I.U INTRODUCTION

SYNOPSIS 1.3

India is still lagging behind considerably on energy frontcompared to tlle world standards. This gap can be narroweddown provided ITItmagement sincerely initiates energy projectsin their plmlls. It is suggested tlUlt ,m exclusive 'ENERGYMANAGEMENT CELL' (EMC) should be guided by ,moutside expert agency. Tbis Exclusive Cell (EMC) should bemmmed by very dedicated, highly motivated and enterprising 1.4engineers/staff. The EMC has to work in a well coordinatedmmmer with the production and lmuntemmce group of runningplmlls. to minimize tbe production losses.

Based on lindings of Energy Audit, project should be 2.Ustructured. evaluated ,md implemented in a well pllmned andcoordinated m,mner by EMC. The Energy Audit should berepeated periodically lor improvements. 2, I

This paper emphl.,ises the need of formation of EMC in eachand every pllmt and elaborates its functions and the workingstyle. Benetits from Energy Projects are bound to outweigh theinput cost/efforts if the projects are attempted earnestly byEMC. suitably backed-up by Complmy's mlmagement.

l.l

1.2

In recent years. a great de,d of emphasis is being "ud onanalysis of energy consumption. because aftlle obvious 2.2reasons - conslfml rising energy costs and its share intotal production costs (up to 40 to 50 per cent in cementpl,mts). Though considerable progress hI.' been made indeveloped countries. we. however. in ourcountry are yetto achieve the desired results.

It will be seen from the following comparison ofenergy 2.3consumption in cement industry tbat we are still laggingbehind considerably:

For energy conservation what is re,dly lacking is ­sincerity Imd application on the part of mlmagement. If1m exclusive cell is fonned for monitoring the energyconsumption and implementing the desiredmoditications witb active participation fromImmagement, benetits are bound to accrue.

In this paper, an attempt has been made to elaborate theconstitution of this Energy Management CeD, tennedas EMC. its role Imd responsibilities and its workingstyle.

CONSTITUTION OF ENER(;YMANAGEMENT CELL

EMC should be headed by "ENERGY MANAGER"(EMl, a wbole time incharge, reporting to mlmagement.

It should be borne in mind that energy m,magement is80 per cent altitude and only 20 per cent technology ,mdIdso that energy m,magement is in competition withnumerous other plant objectives/problems. Therefore,EM has to be a highly dedicated person and witl] fullback-up from Company's top management.

The EM sbldl be guided by 'ENERGY ADVISOR'(EA) whicb shall be ,m outside expert agency.experienced Imd qualitied in energy management. EAsilldl wke-up pllmt audit from time to time so that theprocess/equipment arc upgraded, keeping pace with thelatest technology/developments.

The EM shld! be assisted by a few enterprising engineers,md other s~'l!'f for working as an indepenoent cell and asa separate profit centre.

Comparison!t of cement

Electrical (Kwh)

Thenmd (G.C,d)

COld consumption (I)

(461111 K. c,d/kg)

World India

(Dry Imd Wet ProcessCombined)

110 1511

1I.77 1I.9X

1I.l7 1I.21

The EMC has to work in such a way thatproduction/routine maintenance is least hmnpered.Simul~1l1eously, results arc Idso obtluned, by working inclo:-;e coordination with production/maintenance staff.

2.4 A typicld nrg,mizatioOld structure is shown in ligure I.

J.lI ROLE & RESPONSIBILITY OF ENER(;YMANA(;EMENT CELL

Thus. there is tremendous scope and imperative need for 3.1improvement on energy front.

Broadly, the following activities c,m be identitied inperview of EMC:

- Increasing the efticiency ofexisting installation.

- Investment in new inslallations with betterefliciency.

*** By S. K. Gupta. H. K. DUll. HtlltCC Engineers Private Limited, NewDelhi. India. This paper was presented tn the third Nalillnul Councilfor Ccmcnt and Building Millcrials (NCR) Inlcrnaliunal Scminar unCcmcnt and Building. Matcrials. held in January JlJl)J in New IJdhi.India.

22

Change over 10

techno]ogie:-;/elluipment.energy :-;aving

- Operation ofequipment in an energy saving mmmer.

- Avoid'Ulce of uophUlned shut-down costs.

- Optim,d sizing of installations.

- Reduction in energy costs hy personnel motivation.

Elaboration of goals of energy tmUlagement ,mdmaking tllem known by giving reasons/justifyingthem for implementation.

- Appointment of EA in consultation with Company'stmUlagement and defining his responsihilities.

I,

i

- Regulating the running hoursequipment/auxiliruies.

3.2 Tasks of EM could he dermed as follows:

of

4.0 PRE-REQUISITES FOR ENER(;YMANAGEMENT

The following list may be considered as the pre-requisites forenergy management progrmnmes:

- Flow sheet of production f.~cilities.

- Equipment list.

- Materi,d and gas flows and b,d,mce (for nonmd andmaximum throughput).

- Energy flows and balances (for nonnal andmaximum throughput).

- Production log-sheets.

- Laboratory testing results.

- Demonstration ofL~test techniques/developments inthe field of energy management at regular intervals.

- Machine historystatistics.

damage/shutdown/rep,rir

L

- Receiving reports from EA, analysis ofthe same andfinalize recommendations.

- Establishment of means of financing of project.

Removal of all hindnmces and difficulties inimplementation of energy conservation project.

- Publishing working prognunme(s) for personnelmotivation.

3.3 Tasks of EA could be summarized as follows:

Check. improve, extend and stremnline measuringschemes and activities.

- Develope of a clear, well-defined reporting systemand its updating frum time to time.

- Energy audit of the complete plant including datacollection, evaluation and recommendation on S.Oenergy conservation progrrumne. 5.1

Elaboration of data and development of project.

- Assist in realization of the energy projects.

- Prescription to operators for correct handling ofplantand equipment.

Evaluation of results of energy conservationme:lSures ,md to publish them.

3.4 Responsibilities of other members of EMC are:

To assist/advice/coordinate with EA undersupervision of EM.

To discuss/propagate achievement(s) to theircounterparts.

Motivate plant sUlff on continuous basis.

- Operation manuals of all equipment.

- Trend curves for heat and electrical powerconsumption and other statistical data on daily.weekly, monthly and yearly basis.

- Schematic diagrmn of compressed ,rir and watersupply/distribution network and actual operatingda~~.

- Power distribution diagrmn.

- Energy bills.

Cost of production s~~tements.

- Latest and well-maintained measuring equipment.

. - Highly motivated management and manpower forimplemenUltion of energy conservation projects.

PERSONNEL MOnV AnON

Psychological aspects of the human being is the reasonfor most ofthe troubles, inspite ofthe fact that he usmdlyblmnes others. The reason is usually found to be lack ofratiomil attitude of the man towards energy. Thefollowing could be attributed for this kind of approachof personnel:

- Lack of technical competence.

- Indecisiveness of energy management.

- Under-estimation of potential adv,mtages.

- Negative altitude towards newer technologies i.e.change.

Lack of reliable measuring 'Uld comparisonpossihilities.

Lack of exchange of thoughts and experiences.

- Negative attitude towards consulting.

23

ENERGY MANAGEMENT CELL

TOP MANKJEMENT

r-- PLANT OPERATION

ENERGY ADVISOR ENERGY M.6NAGER I--(EA) (EM)

"""- PLANTMAINTENANCE

TECHNICAL ADMrNISTRATIVE FINANCIALSUPPORT SUPPORT SUPPORT

Figure I. A typical organizatio/lal structure ofEMC

24

Waiting for still better technologies.

- Lack of will for cooperation and accept::mce foradditional/non-routine work.

A typic~d d~velopment of Energy Conservation Project ,md itsevaluatIon IS presented in tigure 2.

6.2 Implementation

- This Exclusive Cell should he incumbered by verydedicated. highly motivated and enterprisingengineers/staff.

EMC has to work in a well coordinated manner withthe production and maintenance group of runningplants.

Based on lindings of energy audit, project(s) shouldhe structured, ev,duated lmd implemented in wellplrmned and coordinated mmmer.

7.11 CONCLUSIONS

- India is still lagging considembly on energy fromcompared to world standard.'.

- This gap can be narrowed provided managementsincerely initiates energy projects and forms anexclusive EMC which sludl work as ,m independentprotit centre.

EMC should be guided by an expert outside agency(ENERGY ADVISOR).

Once the decision is taken in principle. the project should heexpanded to the minute detail and scbeduled so that production~oss/down time i~ the !east. TI~is is very important since anyunprovement pru]ect dlfectly hIts plant operation.

Once the pruject is in prugress, it should be continuouslymonitored so as to maintt~n the schedule.

When plant is restarted after implememation of the project.operation is monitored very closely ~Uld the results arecomp,rred with the inithd predictions.

It is neces1'iary to locate interested. active mld qualifiedpersonnel for energy management schemes. First of allthey should be properly oriented witb company'sattitudes and goals of energy prognunmes wld then.trained to eliminate ignorance/wrong idemci. A premiumor bonus system should be declared which should becommensurate with achieved results. Suggestions andide,", should be invited through suggestionboxes/conferences. This would make the personnelinterested and motivated towards energy projects.

Start of progrmnme with uncertain basis. uncleargoals and uncertainty of financial commitment.

5.2

6.n EV ALlJATION OF PROJECT ANDIMPLEMENTAnON

6.1 Evaluation of project

Lack of interest for training.

- Existing overload of work.

Earlier experience of poor take-off of an energyconservation programme.

Based on the Energy Audit, areas have to be identitied forimprovements. These shall be an,dyzed/studied further andsh,dl be categorized '"' projects. These projects have to beev,duated keeping in view the following:

Effects on up ,md down strewn part of the process.

Shut-down costs (stripping, reconstruction. erectionetc.).

- Operational reliability.

- Maintenance expenses.Energy Audit should be repeated periodic,dly forimprovements.

Ev,duation based on rate of return ,md pay-backperiod.

Based on the returns and pay-back period. priorities of theprojects are assigned.

It can be concluded that if attempted earnestly. benelits ofenergy projects are bound to outweigh input costs/efforts. It h,",to be borne in mind that energy projects can never be attempteddepartmentally with successful results because of cont1ictinginterests/priorities. ltlms to be done by an exclusive cell assistedby an extermd specialist agency (ENERGY ADVISOR).

25

,_,-

DEVELOPMENT OF ENERGYCONSERVATION - PRO JECT

APPOINT ENERGYADV I SOR

PLANT AUDIT

ANALYSIS REPORT NON-VIABLE STOP

VIABLE

DETAILED STUDY

PLANNING· OF ACTI ON S

SHORT MEDIUM MAJORPROJECT( S) PROJECT (S) PROJE CT (S)

PROJECT REA L1SATION

ASSESSMENT OFRESULTS

Figure 2. A typical energy conservation project

26

Tf

EVENTS

Meeting oftile African Ministers in cllarge oflIousingand urban developmentfor tile preparation of tilesecond United Nations Conference on HumanSettlements (llabitat II - City Summit). Dakar,Senegal, 3 October 1994.The African Ministers in chnrge of housing nnd urbandevelopment met in Dakar, Senegnl, on 3 October 1994 lU1d onthe OCC1L~sion of World Habi~~t Day ndopted the DAKARDECLARATION. The full textofthe Declaration is reproducedhere-under.

We, African Ministers in charge of housing and urbandevelopment, meeting in Dnkar, Senegnl, on 3. October 1994for the celebration of World Habitat Dny;

• Taking into accoullt the declarntion by African Ministersndopted in Nairobi on 30 March 1994 on the second UnitedNations Conference on Human Settlements (Habitat II - theCity Summit) which will take place in Istanbu1 in June1996,

• Taking also into accoullt the decisions of the PreparatoryCommittee ofHabi~~tII, at its first subs~mtive session heldin Geneva from II to 22 April 1994,

• Stressing the key role of housing in the development offamilies, as symbolized by the theme of the present WorldHabitat Day: "Home and the frunily".

• Having reviewed settlements conditions in Africn, inpnrticular:

The rapid growth of urban popu1ation and the needto mannge this urban growth better;

- The deterioration of the living environment and theneed to provide approprinte infrastructure for watersupply, solid-waste management, sani~~on andpublic transport;

The Inck of adequate and affordable shelter and theneed to be resolute in adopting facilitating policiesinvolving all s~~e-holders from the public andprivate, formnl and informnl, governmental andnon-governmental sectors;

- The growth ofurban poverty and the need to generatemore productive employment as well as basicservices in low-income areas;

- The impncts of politicnl and social crises and naturaldisasters on human settlements and the need tolaunch actions for disaster mitigation, reconstructionand development for the benefit of affectedcommunities;

• Canscious of the leading role of cities in economic.political, social and culturnl development and nware of thecomplemen~~ relationship which can and must beestablished between cities and rural areas,

We re-emphasize that human settlements should constitute npriority sector for African Governments.

In that perspective, we solemnly commit ourselves to:

1. Adopt and implement enabling, participntory andinnovative housing and urban development policies so as toreach the objectives of Habitat II, namely:

(i) Adequate shelter for all;

(ii) Sustainable human settlements development in anurbanizing world.

2. Define and implement programmes aimed nt preservingthe living environment, upgrading infrastructure and basicservices, as well as reducing urban poverty;

3. Collnborate closely with municipalities and encouragedecentralizntion processes with a view to improving technicnland financial management of cities and their efticiency inpromoting economic and socinl development;

4. Support non-governmen~"l1 and community-bnsedorganizations in their initiatives geared towards improvinglow-income settlements and nlleviating urban poverty;

5. Review, whenever needed, the legnl lU1d regulmoryframework for human settlements development with a view topromoting the nctivities of the public and private sectors andtaking approprinte measures towards the urban infonnal sector.

6. Promote mutually supportive linkages between urbanand rural development, pnrticularly through adequmeinvestments in secondary cities and communicationinfrastructure;

7. Strengthen the role of women and youth in humansettlements development by ensuring their access to education,resources and decision-making processes;

8. FormuInte mitigntion strategies for nntural lmdhuman-mnde disnsters and promote hannonious and equitablereIntions nmong socinl groups so as to reduce the impactofsuchdisasters;

9. Participnte actively in the preparations for Habi~~tII bycreating Nntionnl Bodies involving all public and privnte nctorsin human settlements;

10. Favour the establishment by these National Bodies ofNational Plans of Action including:

- An nssessment of shelter and urbanization trends andissues, based on UNCHS (Hnbi~ll) housing andurban indicators;

27

A review of the effectiveness of existing policies;

- A live-yem tirst-step action prognunme for theperiod 1996 to 21XlIJ.

II. Call on multilateral 'Uld bilateral org,mizations tosupport the Habitat II conference and its preparation in Africancountries.

We t/taJJk UNCHS (Habitat) for having held for the tirst time,and actively supported, the glob'd celebration of World HabitatDay on the AfricrUl continent;

We l.·oJJgrallllale the President of the Republic of Seneg,d, theGovernment 'Uld the Seneg'dese people for their welcomewithin the traditiohal Senegalese Teranga.

Meeting afthe Ministers in charge aflllimansettlemellts in Eastem and Sollthem Africa subregion, preparatory process to the second UnitedNations COI!ference on Human Settlements (HabitatII), Kampala, Uganda, 26-28 Febmary 1995,

The Ministers in charge of hmmm settlements of Eastern andSouthern Africa met in Kamp'da 'Uld adopted, on 28 Februmy1995. the Kamp,da Declaration which is reproducedhere-under:

We. the Ministers in clmrge of hUlmm settlements in thecountries of Eastern lUlU Southern Africa. assembled inKmnpala. Ug'Ulda from 26 - 28 February 1995 to review thein-country preparatory processes for the l-iccond United NationsConference on Human Settlements (Habitat II).

RecalliJJg United Nations General Assembly Resolution 47/180of 22nd December 1992. convening the United NationsConference on Human Settlements (Hahitat 11) with a view toamong other things. arresting in the long-term, the deteriorationof glohal human settlements conditions and ultimately creatingthe conditions for achieving improvements in the livingt.:nvironment of all people on a sustainable basis, with specialattention to the needs and contributions of women andvulnerable groups.

Recognizing f:Uld appreciating the policies f:md prognunmesaimed at improving humf:m settlements conditions world-wideincluding those of the International Year of Sheller for theHomeless (IYSH) 1982-1987; the Global Strategy for Shellerto thc year 211110 'Uld Ihe programme of the United NationsConference on Environment [md Development. Agenda 21.particularly its Chapter 7 on Hum,Ul Senlemems.

R('calling also the decisions of the special meeting of Ministersin charge of hUlmm selliements in the Africa Region on thepreparatory process of the Habitat II Conference held inNairobi in March I~94 whicb reiterated resolution CMIRes146~ of thc OAU Council of Ministers 'Uld illler alia, urgedproper consultation ~U1d coordination at all levels to enhance thepreparatory prOl:L:SS.

Cogllisallt of the dt.:cisiolls of the lirst preparatory session of theUnited Nations Conferencc on HUJl1'Ul Sentements (Habitat II)in Geneva in April llJl.J4 to encourage broad participation in the

28

preparatory process 'Uld in tbe fonnulation of national pl,Uls ofaction.

Further recoglllzlIlg the Dakar Declaration by AfricanMinisters in charge of housing and urban development at theirmeeting in Dakar. Seneg,d. 3 October 1994 on the occasion oftbe tirst global celebration of World Habitot Day in the Africacontinent, calling upon all Afric;:m countries to participateactively in the preparatory processes of the Habitat IIConference.

Conscious of the importrmce of cities a."i centres for economic,soci,d. political ,md cultund activities 'Uld the complement,uyrelationship between cities rmd rural areas.

Taking illto account the "guidelines for National Preparations"prepared by the Secretariat of the Habitat II Conterence.

Noting tbe progress made by some countries, 'Uld tbe difficultiesfaced by others in preparing tlleir natiomd phUlS of actiontowmds Habitat II.

Taking into account the human settlements conditions in theAfrica Region in genend and in tlle Eastern 'Uld Soutllern Africasubregion in p,rrticuiar, namely:

(a) tbe higb population growth rates in Africancountries, rapid urbanization. the increasingdeticiency of services 'Uld lack of employmentopportunities in the rural areas;

(b) the growing inadequacy of shelter in the urbancentres, the deterioration ofthe living environmentand the pressing need to provide appropriateservices and infrastructure:

(c) the vicious cycle of urb,Ul poverty ,md the urgentneed to generate gainful employmen~ so as toenable all sections of society to improve theirliving conditions, in view of tl,e important linkbetween poverty ;:Uld the urban environment;

(d) the impact on hum,Ul settlement conditions ofpolitical/social crises and the ,mned conflicts inthe subregion, as well as natund disasters, resultingin massive loss of hum;:m lives, destruction ofhousing ,md living environmen~ displacement ofpopulations within natiomd boundmies andmassive movement of refugees:

(e) the need to fully involve local governments ,mdcommunities in the decision-making for thephmning, development 'Uld m'Ulagement of ,dlaspects of hum;:m settlements;

COl/cel'lled tbat there ,rre still approximately one billion peoplem;:my of whom are in Africa. who are homeless or lack adequateshelter.

We. the Ministers in charge of hUlmm settlements in the Emaernand Southern Africa Subregion;

l. Re-affirm the decisions and dechrration by Aliic,mMinisters in charge of human settlements on the preparatory

II -~~-----------------------

process to the second United Nations Conference on HumanSel!lements (HabitlU II) adopted in Nairobi, Kenya on 30tbMan;h 1<)94.

2. Endorse the decisions contained in the DAKARDECLARATION on the Habitat II Conference adopted byAfrican Minislcrs in clmrge ofhousing ~U1d urhan devclopmcnt~

in Dakar. Senegal 3 Octoher Illl)4 on the occasion of thece!chlation of World HabillU Day.

3. Commit ourselves tn design. adopt and implementenahling. participatory ~md innovative human settlcmenl<;development stralcgics towards realizing the twin objectives ofHabitat II viz:

(i) Adequate sheller tllr;dl;

(ii) Sustainable human scu]clIlcnts development in anurhanizing world

4. Rccoglli=e Iluu adlXluatc ~hcllcr is a basic prerequisite:for the full development of the hUlmm being and thallhc basicunil for human and IUaterial development, !lIe frunily, c'm onlynourish in a healthy. secure. jlL<;l ~md sustainable environmenl.

5. Recogllizl' also Ihal housing is a powerful stimulus ofeconomic devdopmenl:md an inlegmJ pml ofhuman resourcesdevdopmcni .md nol simply a produci of economicdcvclopmcnl.

6. Emphasize Ihal while m.:cepling Ihat hUlmm seUlemenlissues mUsl he perceived in lenns of sustainahle developmentworld-wide. special cmph'L"i'i should he placed on an Africanperspeclivc Ihal focuses on key priorily arem; of criticalrelev:mce to the suhregion's dcvelopmenlal needs namely:urhan poverty: the dClcriorating um.m environment: energy inrurJ1 and urb:m :rreas; and the rural-uman balance.

7. Rl'-affirm the enabling role of central governments inestahli'ihing positive relationships wilh local governmems andIr.mslaling such me';l'iUreS into effective decentralization ofresponsihilities :md resources.

K Ulldersl'(Jre the critical need for cenlfal governments 10create an enahling envimnmenl and promote strategies,e~llecial.ly Ihrough legislative refonn .md institution-building inIhe land ::md housing fimmce sector, so as to exp::md theparticipation of lhe privale sector, !he CBOs and NGOs in thcdevelopment ofhmmm sCllJcmenis. particuhrrly in lhe provisionof aUllflJable sheller, and necessary inlraslruclure facilities.

9. SU-ess IIml hmmm seuJement policies in Africa shouldsimuU,mellusly address the needs ofbolh urban and rural arC'L';in particular, appropriate linkages should be crealcd with rurr~

afe..1.S so as to enhance Iheir atlnu.:tiveness hy providinginfulSlfUclure. employmenl and services in the rural lrrcas 1Oenahle Ihem retain their populations :m~ minimize th~ currenttreml of mpid oUI-migmtion 10 urhan centres where exislingservices arc already slfained.

10. Emphasize the urgency in addressing the root caURes ofpoverty and developing poverty a1levialion measures especi'~lyfor female-headed household'iand other di~adv.mltlgedsectionsof the population hoth in lhe urban ;md rural areas so as tominimize. illter alia. lIle negative impact of structuraladjustmenl measures in these areas~ such me;:l'iUreH should forman inlegrnJ pmt oflhe emerging global consensus for achievingpolitical ;:md economic stahility. good govern;mce. popularparticipation. taking inlo account gender bahmce. investing inpeople, concern for the environment ;:Uld vigorous privatesector.

11. Commit ourselves to strengthen good govern;:mce. andsound adminiSlnltive llild revenue colJection capacity in hothccnlntl ;:md local government systems. especially in urhancentres. with a view (0 create ;:Ul atmosphere of popularp;:u1icipation. tnmsparency ;:Uld greater nnand.tI accountahiliiyin municipal affairs which will in turn allow these localgovernmenls to provide increasing .UlU hetter services for tllCirconstiluent populations.

12. ResolVe! to redouble our collective efforts in finding amore pennanent solution to the causes of the persistent ma."isiverefugee prohlem in IIle subregion induding contlict -inducedrefugee lmu environmem;:tlly-displaced persons by evolvingmore stable politic.tI solutions in their respective counlfies.

13. Commit ourselves to cooperating and slurring innovativeexperiences including appropriate technologies. andinstitutions for the mobilization of I1n'Ulcial and other resourcesfor hum.m settlement development and nUUlagement.

14. Undertake to give priority consideration to the issue ofIcmd-tenure reform. to ensure equitahle access to land by allsegments of the population especially the poor and thedisadvantaged, drawing inspiration from signiticant reforms.mll good practices in countries of the suhregion. particularly inIhe development of human settlements finance systems <tnd inIhe improvement of informal settlements.

15. Call for the urgent designing and implementation ofinnovative and appropriate linandal mechanisms as well mistrengthening the existing ones IlJ[ the mohilization of bothshort-tenn ::md long-term finance ror shelter development.including pension funds. insunmce funds ::Uld municipal honds.Such mech.misms should enh:'Ulce accessibility to housinglin.mee by low-income sections of the population. taking intoconsideration the many existing infonnal economies in theurban and ruT;:tI aremL

16. Emfl/wsi:e the urgent need to develop .Uld pmmotc theusc of a wide nmge of local huilding materials. as well a.... toreview huilding and land development codes :.md regulationswith a view to create llil enabling environment ~md thusincre::l'iing the affordability ofhotl'iing to a larger proportion ofpeople than would otherwise be the case. recognizing thatdevi.sing schemes that increase the stock of alTorllable housesis a prerequisite to achieving the goal of shelter for all.

29

17. Commit ourselves to continue to give priority to policieswhich encourage and support popular participation in thisprocess. using the combined capacity of central :md localgovernments. the private sector. community-basedorganizations. youth organizations. women associations. andnon-governmental org:mization:-; ~Uld acknowledge the fact thatinternal mobilization and initiative through empowennent ofthe people must provide the principal driving force in therealization of declared human settlements objective:-;.

18. Furtller commit :md dedicate our countrie:-; to thepreparatory process for Hahitat II. hy developing nationalparticipatory processes through national committees. involvingpublic. private. non-govemment'd and community-basedorganization:-; as 'well as women groups ~Uld the youth.preparation of National reports lUld formulation of NationalPlans of Action for Hahitat II. as well as to using relev;:mt andacceptable indicators to mea:-;ure progress in these :md otherareas of human settlements development ;:Uld management inthe posl Hahitat II period.

Ill. Resolve to give full practical recognition to and furtherstrengthen the role of women in human settlementsdevelopment and management by ensuring their unencumberedaL:L:ess to credit ~Old ownership of land as well as by ensuringadequate gender b,d,Ulcc in ,dl aspects 'Uld levels of policy and

Prnl!nunmc decision-makinl!., ,

2( 1. Fllrt!ler Resoll'e to more actively explore i:md utilize theframework :md resources of such sub-regional institutions :L"the Prcferenti,d Trade Area (PTA) of E",tern and SouthernAlrica. Southern Aliican Development Community. theInter-Governmental Authority on Drought and Development(IGADD). the Eastern 'Uld Southern Afrie,Ul MmlagementInstitute (ESAMI). the PTA B'Ulk. the hudding CommonMarket for E",tern mld Southern Africa (COMESA) etc.lmv;.rrds improving the conditions of human settlements andenvirnnment in thc sub-region.

21. Rcclllcsl the uonnr cOllllllunity ~Old the internationalinstitutions to complement our own initiatives hy providinghoth iimuu;ial resourccs lUld technical assistance resources toenahle implementation of hmmUl settlements developmentpolicies :md prognunmes. as well as to facilitate the preparatoryprocess for Habitat II.

22. Cool/lle/u] the Secretary-General of the Habitat IIConference anu Assist'UlI Secretary General of UNCHS(Hahitat) <Old his staff for facilitating and supporting thissuh-regional meeting;

23. EXl'rl'ssapprecialion to thc other organizations that havesupported the meeting namely: UNDP. Shelter-Afrique. UnitedStates Agency for International Development (USAlD) and theUganda National Housing anu Construction Corporation.

24. Cull on African Regional institutjons/org~mi7 ..ations togive stmngcr support tn the Hahilatll Conference preparatoryproccsses in African countries in general .mu in the countries ofthe: Eastern <UlU Southern Afrit:a subRegion in particular.

30

25. Request the Heads of State and Heads of Governmentsto endeavour to attend the Habitat II Summit Conference inIstanbul. Turkey in June 1996 'Uld help make the Conterenee aresounding success.

26. Express profound gratitude to President Yoweri KagutaMuseveni 'Uld the Government of Ug'Ulda for hosting themeeting and to Her Excellency.the Vice President Dr. SpeciozaW'Uldira Kazibwe for graciously opening the meeting 'Uld forthe copious hospitality extended to ,dl the p,rrticip'Ults.

African Regional Ministerial Meeting in preparationfor the second United NatiollS Conference on HllmanSettlements (Habitat II), Johannesbllrg, SOllth Africa,16 - 18 October 1995.

The meeting was auended hy Afric,"l Ministers which endedon 18 October 1995 on an exhihrrating nOle with PresidentNelson Mandela congratulating Ule Alric,Ul Ministers onreaching an African consensus for Habitat II on key issues ofintere:-;t to the continent.

In a lurrd-hitting but optimistic speech. the President of theRepuhlic of South Africa said that Ule specific ch,dlenge Africafaces is that of poverty. ,md that most Aliic,Ul people were toopoor for a pure market solution to the housing problem. "OUfapproach to housing in South Africa. as in other p,rrts of Africa.embodies the principle that the government hrt" lUI imporumtrole to play. But it recognizes that government alone Cllilnotsolve the problem. We tot,dly endorse the need for 'Ul urgentand meaningful partnership of government. the private sectorand homeless communities. I!

President Mandela emphmdzed the role of women in humansettlements development by saying that the success of anyhousing progrmnme is very much a function of the extent towhich women ,rre directly involved. "When we t,dk ahootpeople-centred development." he added. "we should understandthat the involvement of women is often the difference between:-;ucce:-;s .Uld failure." President Mandcla used the occ'Lo.;ion topresent a schol,rrship to David Dladla. a South Afric,Ul pupilfrom KwaZulu-Natal for the best essay in a competitionorganized by the South Afric,Ul Department of Housing forWorld Habitat Day. Atthe same event. a 1995 Habitat Scroll ofHonour was presented posthumously to the late Joe Slovo. firstMinister of Housing in the Government of National Unity. TheScroll of Honour is one ofeight hestowed by the United NationsCentre for Human Settlements (Habitat) on the oCl:~Lo.;ioll ofWllrld Hahilat Day. Dr. Wally N·Dllw. Secretary-Genend ofHahital II. paid trihute tll the late Mr. Slovll for spe,rrheadingthe search for housing solutions and inspiring commitments byall al:tnrs to the development of housing for the uisadvmllagedm~~iority in South Africa.

At a press conference preceding the closing ceremony. theSecreHrry-GenemI of Habitat II summed up the Africancommon position for Habitat II - now adopted 'Lo.; the"Johannesburg Declaration" - ~L" one that rellects therural-urh:Ul balance in human settlements. "Despite till:appellatioll 'City Summit' for Habilal II. Africa feels thenecessity to fight on two fronts: rural lUlU urb.m. AlthoughAfrica is urbanizing rapidly. the majority of its peuple arc still

TrI in rural arem;. The African Ministers prc:-;cnt here wmlt human

settlements policies' in Africa to simult,mcously address theneeds of hoth rund m,d urh,m 'U1"" ,md w,mt to stem the !lowofrural-urhan migration by enh:mcing the attractiveness ofruralarea."; through the provision of infra."itructure, employment ::mdservices to rural areas."

The Jolumneshurg Declaration is the consolidated position ofAliica on the Hahitat II Conference. It encapsulates thecOnlinent"s total politic,d commi"nenl to the Hahitat IIConference ,md to UNCHS (Hahitat). which w,,, reconfirmed'L' the foc,d poinlll1f Illllow-up and monitoring of progress inthe post-Ist,mhul era. The Declaration will ensure that Africa'sconcerns are fully re!lected in Hahitat II's Gloh,d Pl,m of Action- the hlueprinl for sustainahle human settlements developmentin the 21 st century that will emerge from the Hahitat IIConference in lst,mhul. Turkey next June.

The Secretary-General of Habitat II congmtulated the AfricanMinisters for comprehensively addressing prohlems related to

housing timmce and the need to help the poor memhers ofsociety to g,un access to credit. He noted with appreciation thatAfrican Ministers have welcomed the African privaLe sectorandrecognized that the sector had ,Ul important role 10 play inhoosing delivery. He reitemted Habitat's recognition of theneed for strong partnerships mnong the vmious actors, includinglocal authorities. the private sector. non-governmentalorganizations ~md community-based organizalions inaddressing human seltlements issues.

The South African Housing Minister SankieMthembo-Nkondo, reiterated Aliica's concerns ahout housingtinance ,md urged the international community to help Aliicaaddress its housing backlog. Speaking on hehalf of thedelegates, the Nigerian Minister for Housing. Alhaj AhdullahiAdamo, paid glowing trihute to the Government ofSouth Africafor successfully hosting the meeting.

The full text of the Johannesburg Declaration will be printed inthe next issue of the Jounwl

31

PUBLICATIONS REVIEW

Published by UNCHS(Habitat)

Applicatioll ofBiomaxs -Ellergy Techllology

The av,ulahility of energy ,md the security of its supply are ofpanunount importance to all human communities.Unfortunately, in most countries - hoth developed anddeveloping - current energy markets ignore the social andenvironmental costs .md risks associated with fossil-fuel use. Ifextcmalities such as employment. import-substitution, energysecurity :md environment are considered. then biomass systemscompare very favourahly with fossil-fuel systems.

Biomass currently account, for ahout 14 percentofthe world'senergy supply ,md is the most import,mt source of energy forthree quarters of the world's population living in developingcountries. With fm:reases in population .md per capita dem;:md,and depletion of ll)soil-fuel energy resources, the dem,md forhinmass energy is expected to increase rapidly in developingcountries. Even in developed countries. hiomass is beingincre",ingly used. For example, the United States of Americanow I"" 9000 MW of hiamass power plant' and Sweden, whichderives 14 per cent of its energy from hiOlm"s h'l' phms toincrcR"e it further as it phases down nuclear fmd fossil-fuelphmts into the next century. With technologies av,ulable today,hiomass can provide modern fuels such as electricity and liquid

32

ruels, in addition to more traditional cooking ruels, ,md thisenergy c,m be produced [lOd used in ,mdenvironmentally-sustainable Immner.

Yet. hiomass energy continues to receive the lowest priority inenergy planning in developing countries, M,my factorscontribute to this: the unreliability or production Mdconsumption statistics; the uncertainty of production costswhich are quite site-specific; its diverse sources and end-uses;and its interaction witb hmd uses.

Integrating biomass energy in nmio",d energy plMning ,mdpolicy-making on 'm eqmd footing with other energy sourceswill not be easy ,md will require concerted action at national,md sub nation,d levels. A reliable infonnation b,,,e will baveto be developed on the supply ,md utilization ofbiom,,,s energyin the country; the policy environment must he made responsiveto the need of the biomass-energy sector, research, developmentand engineering effons will have to be stepped up in requiredareas; ,md the commercialization of biom'l<S technologies willhave to be promoted through selective and well-targetedsubsidies lUld fiscal lmd other fonns of incentives.

This publication fonns a pm'! of the Centre's continuing effortsto promote wide dissemination lmd commercialization ofrenewable energy technologies - .m area of expressed concernin Chapter 7 of Agenda 21 on sustainable hUlmm settlementsdevelopment.

15Hpp., HS/2H7/93E, ISBN 91-1-131211J-H

Buoklet all small-scale tecl/llologiesfor cOllstructioll

One of the main rea.'ions for inadequate national capacities torespond to the construction requirements of the low-incomepopulations is that there is mi yet no comprehensivetechnolngic,~ policy to overcome the limitations of thesmall-scale construction sector. The vast majority ofenterprisesoperating in the small-scale sector, and particularly tllOfie in theinfonnal sector. continue to rely on traditional technologieswith very little ability or opportunity to upgrade and improvetlleir production process or tll diversify into new product lines.

Appropriate <Uld inllovalivc tcchnologics difTer from country tocountry depending on their local conditions, natural resourceendllwment, <lvailable skills ;.mu sncio-cultural traditions.However, most of these technologies arc modifiahle andadaptahle to different localities if other prerequisites :-iuch m'iinfnnnation llow. ah:-iorplion capacity. adequate policyenvironment. <UlU favourable financial condition:-i are fiet tocncourage nL;W small enterpri:-ics to apply such tcchnologies.

Thc choice or the right teclll1Dlngy in a given context. takingillio account thc natural re:-iource endowment i:-i crucial. Choiceof tccluHllogy rclatc:-i 10 a v:.uiety of i:-ifiue:-i none of which canhc lakcll for granlL;u. A :-iL;lccteu technology IllU:-i1 follow a

The industrialized counliies bear ti,e main responsibility ofleading the way in chlmging consumption lmd productionpatterns through energy efficiency, efficient use of otherresources. replacement of non-renewable resources byrenewable ones, and minimization of waste production andpollution.

Human settlements, and particularly large urbanagglomerations, are major contributors to environmentaldegradation ,md resource depletion. At the same time, humansettlements, large and small, are also :rrem; of unusedopportunities, creativity, economic growth, communication;accessibility for transfer of knowledge; and ,m enicient andeffective anackon waste and pollution.

The undesirable environmentlU implications of settlementsgrowth can be addressed lmd reversed. Hmmm settlements canbe managed in an orderly and equitable manner throughparticipatory ,md resource-conscious pl,mning andmanagement. This enabling approach applies to ,Ul urbanfunctions, such '" hmd use, construction. water supply,sanitation, waste disposal, transport (md recreation.

bilIion people - will live in urban settlements. A growing shareof the world's poor will live in rapidly-growing urbanagglomerations.

The intolerable and worsening living ,md workingenvironments of the poor in urban slums and rural area.,;. withtheir implications in tenns of human suffering, deterioratinghealth and reduced life expecumcy, are a major determinant ofpoverty, Therefore, the improvement of the living and workingenvironment of the poor is a priority concern.

BOOKLET ONSMALL-SCALETECHNOLOGIESFOR CONSTRUCTION

114 pp., HS/302/93E, ISBN 92-1-131224-8

~------=------~ number of parmneters, the most signiticant of which, are:i' adaptation capability to suit the specific local condition;[ effective marketability; detennination to make it succeed; and

the efforts to enhance competitiveness by reducing costs ofapplication.

UNCHS (Habitat), in line with its Immdate ,md in ,m attempt todisseminate technologicrd infonnation in the constructionsector, has compiled a number of appropriate technologies (inthe form of technology profiles) which are presented in thispublication.

The compiled technologies in this publication are intended tobe ofuse by individuals, slmdl construction enterprises, and ,dsodecision-makers who wish to acquire and make use of suitabletechnologies for the construction of low-cost housing in bothurban and rural areas.

Better planning and m:magement of human settlements,including access to :md use of environmentally-soundtechnologies, lmd reduced dem,md for mobility and tnmsportcan produce signiticant energy savings IUld therefore helpprevent global wlUming and climate change.

International cooperation must be intensified to encourage andsupport natiomU lmd 10Cld efforts in all countries to achieve thedual objective of sustainahle developmem: meeting thedevelopment aspirations of people today lmd safegmrrding theright of tomorrow's generations to do the same in healthy andhum,me environments.

This publication address issues such as:

UNITED NATIONS CENTRE FOR HUMAN SmLEMENTS (Hlbitltl - Hum:m settlements Md sustainable development

- Solid-waste management policies retlectingsustainable-development principles

S:mitation lmd wastewater-management policiesrenecting sustainahle-development principles

Humlm settlement mlmagement lmd sustainabledevelopment

- Sustainable land-resources Immagement

Pimple, settlemellts, clll'irOllment and develo[Jment

Sustainable development means improving the quality of life ofall. It c,mnot be achieved in a world where more than I bilIionpeople live in absolute poverty. It is unacceptable, and eveninhmmm, to talk about long-term environmental sustainabilitywithout co_"sidering the shoft-term problems of mere survivalfor such a large portion of hmmmity.

Glohal urh,mization will continue. While ,Umost half of ti,eworld's population is ,Uready urhan, hy the first quarter of thenext century the majority of the world"s inhabitants - over 5

- Water-supply policiessustainable-development principles

rellecting

33

(@)

• PEOPLE,• SETTLEMENTS,• ENVIRONMENT

ANDI_ DEVELOPMENT'

UNITED NATIONS CENTRE FOR HUMAN SETTLEMENTS (H,bil,t)

Sustainahle energy systems for human settlements

- TIi.msJ1Il!1 IXllicies rclkcting sllslain:lhle-uevel{Jpmcntpolicies

- ('tlllstruetioll-seetor pnlicies fur sustainable humansctllcmcnls L1evelllJllllcnt pp 55.

S1l[J[Jor/illg the illlorlllal sec/or ill loll' - illcollleselllemell1s

The lIniteLl Natitlns Centre I"or Human SellJements (Hahitat)has. for many years. heen emphasizing tile impnrtam;c Drl(lw-incOIm: housing developmellt in national prognuTImcs ofcCllIllllniL gnlwlll and employment generation. The ptllcntial ofthe htlLlsing SCClll!" ,lI1d tlr,hc constructiun ilH..Iustry in gcnerall{)cn:att: large numhers Ilf johs for unskillcu amI semi-skillet!workers. to huild inuustrial strength Ull the Imsis or indigelltlLJSinputs of human. natural WHJ financial resources, :'U1U IIIcstablish tIll: hUlI1,m scttlemcnts founuatilll1 for the functhll1ingof all sectors of tile natiunal economy gives constructioninvcstlllclll a lirst priority in practically all developingclllllltries. With a wellRcstablisheu Clll1structin!l inuustry. otherindustrial sectms can bL: pftll110ted on a self-sustaining hw~is

insh:adlJf remaining within the clll1S1raints orimport-tlepem1entactivitics,

SpilHlllcn~cts fnllTlthe c{l/lstructi{lIl !lrhuman settlemL:nts willvary from country III CtHJllIry, Sll thattlwre can hL: no univL:rsalhlllcprint for linking human SL:Ilh:IJIL:IlIS developmcllt to tlthercllIpltlymcnt-gencralinl:! and int.:tJIIll:-generating activities.Howcver. il can gcncrally he expected that the hulk tlr human

34

J •

UNITED NATIONS CENTRE FOR HUMAN SElTLEMENTS (Habitat)I

E. SUPPORTING~r THE INFORMAL

..~~., SECTOR INI 'LOW-INCOME

SETTLMENTS

selliemenis L1evelopmcnt will rely on Ihe eapacltles nl" Ihesmall-scale. luw-technology sector (usually referred to ,L" theinfonnal sector), Therefore. it is reasonahle to assume that theprimary spread-elTects ofhum,m settlements develllpment willhe found in the same sector. By integrating informal-sectorsupport prognunmes in human settlcments ,md related fields.gllvefllmcl1ts can strengthen hum~U1 settlements clements.particuhu'ly those focused on low-income housing, and at thesame time. quickly multiply the impacts of investments ininfrastructure and other facilities.

This uOl.:ument suggests some of the principles which apply tothe promotion of infonnal-sector activities in connection withImv-income hOllsing progr::unmes. Three C,L"e studies arepresented tn illustrate ways in which cmployment ;:Uld housingpJ'llgr~unmes have heen linkl:tI in particular instanccs in Inui.<L

44 pp.. HS/142/HHE. ISBN ~2-1-13111711-~

Improl'iug income and hOflsing: employmefltgenerlltioll inlow-income selllemenls

11 has heen widely recogni1,eu' t1iat employment. incomes allllaccess to housing lUld associated services afe highlyinterrelated, The higgest constraint to L1eveloping improvmJhOllsing for the lowest-incume groups is thdr poverty. Theirincllllles are too meagre or Ion unslahle to permit Ihecommitment of scm'ce resourccs hI shelter. P(IOr pcoph.: tirst andrmelllllSt need ttl generate income or incre:L"e their earning 10impmve their living conditions in general :UlU their housing inparticular.

The l1uyority of the populations ofcities in developing countriesarc employed in· or derive income through small-scaleenterprises and irr" housed in seliChelp ,ettlements. The,eselliements not only provide a place in which to live. they offerincome-generating opportunities and an entry point 10 the urbanecol1omy.

Although poverty is not only a condition of insuftlcienl incomebut a function of lack of access 10 land or security of tenure. toinfonnation tmd to active participation in the decision-makingprocesses affecting the live."i of low-income people. the mainfocus here is on income generation ~md employment creation.

This puhlication exmnines the relationship hetween incomegeneralion ,md hum:m settlements by focusing on arewci whereintervention might hene"t U,e development of hoth improvedshelter and income-generating activities. The topic is coveredin live main chapters. Chapter I provides a general hackgroundto the ,uhject; Chapter II de,Us with the potentkU for incomegeneration :md employment generation irithe construction andhuilding-materirU, sector; Chapter III exmnines the possihilitiesfor promoting income-generating activities in humansettJements: Ch:lpter [V discusses the opporLunities tilremployment generation in the provision and maintcmmce ofh,",ic-urh,Ul services; and Chapter V concentrates on anexmnination of the institutional-support mech,Ulisms requiredto implement the proposed strategic responses.

72 pp.. HS/l89/89/E. ISBN 92-1-131110-0

UNITED NATIONS CENTRE FOR HUMAN SETTLEMENTS (Habitat)

30