environmental company of sao paulo state – cetesb ... · fabric filters are also referred to as...
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ENVIRONMENTAL COMPANY OF SAO PAULO STATE – CETESB
REGIONAL CENTRE OF STOCKHOLM CONVENTION ON POPs FORLATIN AMERICA AND THE CARIBBEAN REGION
V INTERNATIONAL TRAINING PROGRAM ON ENVIRONMENTAL SOUND MANAGEMENT ON CHEMICALS AND WASTES, ESPECIALLY ON PERSISTENT
ORGANIC POLLUTANTS (POPs) AND MERCURY (Hg)
MANAGEMENT OF UNNTENTIONAL POPs AND ATMOSPHERIC EMISSIONS CEMENT KILNSEng. Maria Cristina Poli
2016
Sao Paulo – SP – Brazil
Cement Kilns
Stockholm ConventionAnnex C - Non-intentional production
Part II - Source Category
EVOLUTION OF CEMENT PRODUCTION IN LATIN AMERICAN (million tons)Countries 2003 2004 2005 2006 2007 2008 2009
Argentina 5.2 6.3 7.6 8.9 9.6 9.7 9.4
Brazil 35.1 36.0 38.7 41.9 46.5 52.0 51.7
Chile 3.6 3.8 4.0 4.1 4.4 4.6 3.9
Colombia 7.3 7.8 9.9 10.0 11.1 10.5 10.0
Mexico 31.9 33.4 35.4 38.4 39.2 37.7 35.4
Venezuela 4.4 5.0 5.8 7.2 9.0 7.7 8.0
LAT. AM. TOTAL
112.4 118.2 130.4 142.6 151.5 157.2 153.4
Sources: Cembureau, SNIC, Association of countries, Jefferies International
GROUPS, FACTORIES AND CAPACITIES INSTALLED IN VARIOUS COUNTRIES - 2011
Countries ProducingGroups
Factories InstalledCementCapacity(Mt)
Argentina 4 17 18.1Brazil 14 75 73.2Chile 4 11 7.1Colombia 5 20 20.5Costa Rica 2 3 2.4Mexico 5 34 58.7Paraguay 1 2 0.7Peru 5 7 11.0Uruguay 3 5 1.5Venezuela 3 10 9.9
Sources: Global Cement Report 9th Edition
Stockholm Convention Annex C -Part II
Category of industrial sources with relatively high potential for formation and liberation of
Dioxins and Furans (D&F)D&F are formed and released unintentionally
from heat processes, which have organic matter and chlorine, as a result of incomplete
combustion or chemical reactions.
Cement Kilns
The cement manufacture process consists of four main stages:
– Extraction and grinding of raw material– Homogenization of raw material – Clinker Production– Grinding of cement
Cement Production
Extraction ofraw material Grinding and
Homogenization
kiln
DispatchStorage silo
Storage siloMixing and grinding of cement
ESPSupply of raw material(Flour)
SystemClinker
gassolid
• The main raw materials are clay and limestone.
• The manufacture of the cement begins with calcination,which is the decomposition of the calcium carbonate(CaCO3) at 900 °C into calcium oxide (CaO) and carbondioxide (CO2).
• Next, the lime, at temperatures normally between 1,400and 1,500 ºC, reacts with the silica, alumina and ironoxide, forming "clinker".
• The clinker is ground together with gypsum (CaSO4) andother additives to produce cement
• There are four types of processes for the manufacture ofcement: dry processes, semi-dry processes, semi-wetprocesses and wet processes
Dry process
Chimney
Clinker Rotary kiln Cooling
Kiln gases
Drying silos
Supply and mixture of
raw material
“The burning of hazardous waste in cement kilns does not affect the formation of dioxins and furans;
dioxins and furans are formed after combustion”
Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT),
EPA
(Federal Register, 64 FR 52876, September 30, 1999).
Rotary KilnCyclone
Preheater
Clinker Cooler
«De-Novo-Synthesis»
550 [°C]720 [°C]
1200 [°C]2000 [°C]
850 [°C]
0 [sec] 8 [sec]
25 [sec]
Gas FlowMaterial Flow
800 [°C]
30 [°C]
1450 [°C]
900 [°C]
350 [°C]Range 400-800 [°C]
Temperature and retention time in a cement kiln with pre-heater
“Synthesis Again”
D&F emission factors for the production of cement
Type of process Emission factorsµg of D&F/t of cement
Vertical kilns 5.0Old wet process kilns, ESP with T >300°C 5.0Rotary kilns, ESP/fabric filter at 200-300°C 0.06
Wet process kilns, ESP/fabric filter with T< 200ºC
0.05
Dry kilns with pre-heater or precalciner with T<200ºC
0.05
Source: Toolkit 2003
Emission factors by type of source
Production of mineral products - Cement Kilnsμg TEQ/t of raw material or product
0,001
0,601
1,201
1,801
2,401
3,001
3,601
4,201
4,801
Wet kilns, ESP temperature >300 °C Wetkilns, ESP/FF temperature 200 to 300 °C Wet kilns, ESP/FF temperature <200 °C andall types of dry kilns
• All cement kilns must be equipped withelectrostatic precipitators or fabric filters,or both, for the control of particles.
• Pollution control equipment for acidgases are not used in cement kilns as theraw materials are highly alkaline andallow the control of acid gas
The unintentional formation of POPs may occur within the ESP at temperatures between
200ºC and 450ºC.
Lower D&F emission have been observed when the ESP/chimney is below
255 ºC
Fabric filters are also referred to as baghouses or bag filters. These devices for controlling
particulate matter can effectively remove
unintentional POPs that may be associated with the
particles and vapors that the particles adsorb in the escape
gas flow.Fabric filters are sensitive to acids and, therefore, they are normally used in conjunction with washers for removing
acid gases.
Factors that affect the formation of D&F in cement kilns
• Type of kiln• Burning condition
– Constance of fuel/waste supply– Constance of fuel/waste characteristics– Adequate oxygen content– CO monitoring in the chimney
• ESP operating temperature• Efficiency of the ESP or fabric filter• Temperature in the chimney• Minimize the consumption of energy by using pre-
heaters or precalciners
• The cement industry consumes largequantities of energy, which representsaround 40% of production costs
• The most common fuels are petcoke,carbon and various types of waste
STRUCTURE OF CONSUMPTION IN CEMENT
SECTOR (%)
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1974
1977
1980
1983
1986
1989
1992
1995
1998
2001
2004
OTHERS
PETROLEUMCOKE
CHARCOAL
ELECTRICITY
FUEL OIL
MINERAL COAL
Co-processing
The use of waste in industrial processes such as cement production or other industrial processes involving
combustion where the fuel or raw material is replaced by waste or a
waste mixture (blend)
State of São Paulo
• 02 industrial waste blend co-processingkilns
• 01 tire co-processing kilns• 02 kilns in licensing process for co-
processing tires• 01 kiln for co-processing tires +
agrotoxic packaging
General Co-processing Principals
• The management of waste must be respected• The emission levels must not be higher than those of
cement production with traditional fuel• The quality of the cement produced must not be altered• Staff, processes and systems that demonstrate
commitment to safety, protecting the environment and health must be provided
• They must be able to control inputs and parameters required for effective co-processing
• Good relations with the public and with the neighboring population must be maintained.
• Training for employees• Emergency plans
Reusing energy
• For waste to be used as a fuel substitutefor energy re-use purposes, its lowercalorific value, on a dry basis, must begreater than 2775 kcal/kg (5000 Btu/lb).
• Waste with a lower calorific value, on a dry basis of less than 2775 kcal/kg must be studied case by base.
Reuse as raw material substitute
• For waste to be used as a raw materialsubstitute, it must have a similar chemicalcomposition to that normally used in theproduction of clinker.
Co-processing is not considered
• Plant waste resulting from agricultural activity,such as sugarcane bagasse, rice straw, etc.
• Plant waste resulting from the food producttransformation industry, such as peel, citrus rind,citrus fruits used for the extraction of central oils,etc.
• Office waste (paper and cardboard)and personal protection equipment
(PPE) generated at the plant itself
Types of waste frequently used as fuel in cement kilns
• Used tires• Oil residues
• Industrial waste
Solid fuelSolid fuel
Supply of waste and raw material
Liquid fuel
Main burner
Calciner
Bucket elevator
Kiln
Co-processing tires
• Use of shredded or whole tires• Does not produce waste in addition to that
generated in the production of cement• Metals in their bodywork are incorporated
into the clinker, replacing the addition ofpart of the iron ore.
Typical Composition of Tires (%)
Material Passenger car tires Load vehicle tires
Natural rubber 14 27Synthetic rubber 27 14Carbon black 28 28Steel, textile fibers and glass 14.5 14.5Antidegradant tarp and curing accelerators
16.5 16.5
Source: Oswaldo Aly, Scrap tires, Alternatives to significant reduction of this liability
Burning Feasibility Study
Test Burn
Blank Test
Continuous monitoring
Emission limits Interlocking
Supply Rate
Licensing Stages
Emission LimitsBrazil São
PauloParticulate Matter mg/Nm3 at 11% O2 (a) 70 70
Kg/t of supplied flour - 0.15
Sulfur oxides (SOx) mg/Nm3 at 10% O2 (a) - 350
Hydrochloric acid (HCl) Kg/h 1.8 -mg/Nm3 at 10% O2 (a) - 10
Hydrofluoric acid (HF)mg/Nm3 at 7% O2 (a) 5 -mg/Nm3 at 10% O2 (a) - 4
Dioxins and Furans (b)ηg/Nm3 at 7% O2 (a) 0.5ηg/Nm3 at 11% O2 (a) - 0.1
Nitrogen Oxides (NOx) (c) mg/Nm3 at 10% O2 (a) - 800
(a) In normal conditions (0° and 1 atm), dry basis. (b) Expressed as 2,3,7,8-TCDD(c) Expressed as NO2.
Emission LimitsBrazil São Paulo
Lead (Pb)(mg/Nm3 at 7% O2) (a) 0.35 -
(mg/Nm3 at 10% O2) (a) - 0.275
Cadmium (Cd) (mg/Nm3 at 7% O2) (a) 0.1 -
Thallium (TL) (mg/Nm3 at 7% O2) (a) 0.1 -
Cd+TL (mg/Nm3 at 10% O2) (a) - 0.05
Mercury (Hg)(mg/Nm3 at 10% O2) (a) - 0.04
(mg/Nm3 at 7% O2) (a) 0.05 -
As+Be+Co+Ni+ Se+Te (mg/Nm3 at 7% O2) (a) 1.4 -
As+Be+Co+Ni+ Se+Te (mg/Nm3 at 10% O2) (a) - 1.0
As+Be+Co+Cr+ Cu+Mn+Ni+Pb+Sb+Se+Sn+ Te+Zn (mg/Nm3 at 7% O2) (a) 7.0 -
As+Be+Co+Cr+ Mn+Ni+Pb+Sb+Se+Sn+Te+ Zn (mg/Nm3 at 10% O2) (a) - 5
(a) In normal conditions (0° and 1 atm), dry basis.
Stockholm Convention, Co-processing
Does not establish limits for any sourcesof dioxins
Recommends that priority sources takemeasurements
Sampling in chimney -Brazil
– USEPA 23 Method– Type of collection: isokinetic– Absorption of compounds in XAD2 resin– Collection time: ± 3 hours/sample– Number of collections: 03 collections in
chimney and 03 field control + 01 travel control
– Analysis method: EPA 8290
Results of Dioxin and Furan Sampling in chimney at cement plants without waste
supply
ng/Nm3, expressed as 2,3,7,8-TCDD
Source: ABCP - Brazilian Portland Cement Association - 2005
Unit 1st collection
2nd collection
3rd collection
average
1 0.0024 0.0025 0.0018 0.00222 0.0016 0.0023 0.0021 0.00203 0.0071 0.0035 0.0025 0.00444 0.0010 0.0015 0.0010 0.00125 0.0075 0.0047 0.0027 0.0050
Results of Dioxin and Furan Sampling in chimney at cement plants with waste supply
ng/Nm3, expressed as 2,3,7,8-TCDD
Smoke box: 10% shredded tires 0.0024 0.0040 0.0212 0.0092
Smoke box: 11% shredded tires 0.0018 0.0075 0.0040 0.0044
Smoke box: 10% shredded tires + SPL raw material 0.0168 0.0211 0.0209 0.0196
Smoke box: 14.1% shredded tires 12% blend 0.0207 0.0026 0.0224 0.0152
Smoke box: 30% shredded tires + rice husk 0.0598 0.0592 0.0406 0.0532
Source: ABCP - Brazilian Portland Cement Association - 2005
Results of Dioxin and Furan Sampling in chimney at cement plants with waste supply
(Blend)
ng/Nm3, expressed as 2,3,7,8-TCDD
Heat replacement: 15.9% 0.1034 0.0990 0.0804 0.0943
Heat replacement: 18% 0.1624 0.1668 0.1676 0.1656
Heat replacement: 20% 0.0035 0.0039 0.0045 0.0040
Source: ABCP - Brazilian Portland Cement Association - 2005
Results of Dioxin and Furan Sampling in chimney at cement plants with waste supply
(Blend)
ng/Nm3, expressed as 2,3,7,8-TCDD
Torch: 4.46% waste 0.0163 0.0128 0.0079 0.0123
Torch: 70% coke 30% waste 0.0543 0.0066 0.0792 0.0467
Torch: 70% oil 30% waste 0.0500 0.0724 0.1581 0.0935
Source: ABCP - Brazilian Portland Cement Association - 2005
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37
0
0,05
0,1
0,15
0,2
PCDD / F Emissions of the cement industry in Brazil(ng/Nm3, expressed as 2,3,78-TCDD)
Source: ABCP - Brazilian Portland Cement Association - 2005
D&F Emissions of the cement industry in Europe(ng/Nm3, expressed as 2,3,78-TCDD)
Source: Co-processing, Myths and Truths on Dioxins Emissions - Kåre Helge Karstensennte
D&F Emissions of the cement industry in Germany in 2001(ng/Nm3, expressed as 2,3,78-TCDD)
Source: Co-processing, Myths and Truths on Dioxins Emissions - Kåre Helge Karstensennte
Waste with high chlorine content
• Problems with kiln joining, causing damage to the kiln
Comparison of the D&F atmospheric emission results in kilns in Heidelberg with and without the
use of alternative fuel
(40% energy replacement)
Source: Co-processing, Myths and Truths on Dioxins Emissions - Kåre Helge Karstensennte
(0.29)
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0 20 40 60 80 100 120 140 160
Emis
sion
s in
ng
I-TEQ
/m3 Normal
fuel
With secondary fuel
With raw material replacement
D&F Sampling Research Institute of the German Cement
Industry
Source: Co-processing, Myths and Truths on Dioxins Emissions - Kåre Helge Karstensennte
Hg Emissions
0.1 to 0.035 g/t of cement
• Resulting from:– Raw Material– Fuel– Co-processed industrial waste– Used of RDF (Refuse-Derived Fuel)
Hg Concentration in Raw Material
Hg Concentration in fuel
Hg Concentration in RDF
Hg Concentration in waste used as fuel in Brazil
• Minas Gerais ≤ 10mg/kg• Paraná ≤ 10 mg/kg• São Paulo 0.32 mg/kg
Hg emission limits in cement kilns with use of waste
Country Emission limit(mg/Nm3)
Observation
Mexico 0.07 at 7 % O2
El Salvador 0.05 at 10 % O2
Costa Rica 0.24 Sum of Hg and Cd at 10% O2
Colombia 0.05 at 11 % O2
Venezuela 0.05 at 10% O2
Chile 0.109 at 10% O2
USA 0.12 at 7% O2
Canada 0.15 at 10% O2
Indonesia 0.2 at 7% O2
Thailand 0.10 at 7% O2
Morocco 0.10 at 11% O2
Hg emissions at cement manufacturers across the world
Hg emission control in cement kiln
• Careful control of all substances entering the kiln• Good burning conditions
– Constance of fuel/waste supply– Constance of fuel/waste characteristics– Adequate oxygen content– CO monitoring in the chimney
• Periodic purging of waste of control equipment such asESP and fabric filter, recycled in the kiln.
• Addition of activated carbon before the fabric filter.• Do not use hazardous industrial waste with mercury in
kilns.
Other emissions
• ESP or fabric filter combined with good burning condition, expected PM emission should be 20 to 30 mg/Nm3
• Special care must be taken in relation to metals, observing the return of ashes from the ESP/fabric filter into the kiln. One control measure is to limit metal contents in the waste supply rate.
Continuous Monitoring
• The co-processing unit must keep thecontinuous monitors installed in thechimney calibrated and operating at thefollowing parameters:
CO, O2, THC and NOx.
• In kilns that use SNCR for controlling NOx,the EC requests the continuous monitoringof NH3
Waste Monitoring
All waste received by the waste mixing unit and/or by the co-processing unit should be analyzed previously in order to prove compliance with the requirements established in environmental licenses.
Waste MonitoringThe company must have a waste analysis plan, which must cover, at
least:
• The origin and characterization of the waste• Sampling methods used• The parameters that will be analyzed in each type of
waste, methods and frequency of analysis, and testingdetection limits
• Incompatibility with other wastes• Analysis recording (reports with signature of the
responsible person) and• Availability of counter-tests (site and length of storage,
amounts and form of packaging, traceability, etc.)
Monitoring Operational Parameters
In additional to the normal parameters of theproductive process, the co-processing unit mustmonitor the following parameters continuously:
• Supply of waste• Fuel consumption• Flour supply• Kiln temperature• Temperature at waste supply point• Operational parameters of the PCE
Environmental Monitoring
This monitoring is established case bycase, based on the Risk Analysis Study,Atmospheric Dispersion Study and on thecharacteristics of the area and itssurroundings, such as, proximity ofresidences, vegetation, agriculturalcultures, bodies of water, etc.)
Inspection and Maintenance• The co-processing unit must have a preventive
maintenance program• The maintenance program established must be duly
documented and those involved must be duly trained.• All measurement and monitoring equipment and EPS
must be included in the maintenance program.• Documented procedures must be established
determining the calibration actions needed for themeasurement and monitoring instruments to maintainthe measurement capacity required.
Thank you very much !