energetic-environmental assessment of a scenario for brazilian cellulosic ethanol

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their importance has not yet garnered as much attention as fossilfuel and climate change.

Considering that world energy demand is predicted to increaseby 40% (from a 2010s consumption of 230 million barrels of oil

consumption in ethanol production, labor quality during harvestseason, among others (Santa Barbara, 2007; Giampietro andMayumi, 2009; among others). Trying to overcome these criti-cisms and to be well received by society, scientists are conductingresearch aimed at producing ethanol from lignocellulosic material,called as second generation ethanol. This production processmaximizes waste reduction through the closed-industries concept,i.e. material and energy previously considered as by-products byone process are fed back to other processes as raw materials. This

* Corresponding author. Programa de Ps-Graduao em Engenharia de Produ-o, Laboratrio de Produo e Meio Ambiente, Universidade Paulista, Rua Dr.Bacelar 1212, 04026-002 So Paulo, Brazil. Tel.: 55 11 55864127.

Contents lists available at

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Journal of Cleaner Production xxx (2012) 1e16E-mail address: [email protected] (F. Agostinho).this phenomenon is called Peak Oil and characterized by highenergetic and economic cost to make oil available (Campbell andLaherrre, 1998; Cleveland, 2005). Since the energetic issue is anurgent and real problem, and since that energy market affectsglobally the political-monetary balance, alternative energy sourcesto fossil fuels are considered extremely important for governments,scientists and entrepreneurs worldwide. Other resources are alsocrucial to society, for example fresh water, agricultural lands andfood (Meadows et al., 2004; Hall and Day, 2009; MEA, 2005), but

where it is produced. Brazil is recognized as a huge producer of rstgeneration sugarcane ethanol, reaching 28 billion liters in 2008/2009 (UNICA, 2011), corresponding to 12% of all liquid fuel used fortransportation in Brazil (Balano Energtico Nacional, 2011). Toreach that high sugarcane production, 6.7 Mha of land usingconventional agriculture were required (UNICA, 2011).

Large-scale ethanol production and its expansion are beingcriticized by some researchers based on arguments related to netenergy output, biofuel versus food competition for land, waterEcological rucksackGas emission

1. Introduction

Petroleum, natural gas and coal cenergy consumption worldwide (Whigh demand considerably reduces thprojected to be on the decline due to0959-6526/$ e see front matter 2012 Elsevier Ltd.doi:10.1016/j.jclepro.2012.05.025

Please cite this article in press as: AgostinhoJournal of Cleaner Production (2012), doi:10CEP and another alternative small-scale system. For this, a multi-criteria approach was consideredthrough the following methodologies: Embodied Energy Analysis, Ecological Rucksack, EmergyAccounting and Gas Emission Inventory. Results show that Biorenery scenario has better rating thanCEP for the most indicators when the functional unit is mass of ethanol produced, but when dealing withoverall system performance, the Biorenery performance worse. Neither the Biorenery nor CEP wassuperior for all indicators, showing the existence of a trade-off. On the other hand, the small-scale systemsuggests being the best alternative if the aim is to get higher energetic-environmental performance.

2012 Elsevier Ltd. All rights reserved.

e about 87% of primaryil Outlook, 2010). Thisral stocks and has beenity during next decade;

equivalent to 323 millions in 2030 World Oil Outlook, 2010), somebiofuels are being considered part of the answer to move to a lowcarbon-emitting fuel for transportation. Nevertheless, there areseveral technological routes and raw material available for biofuelproduction and the characteristics of a specic route should neverbe generalized to any biofuel, because it depends on how andKeywords:BioreneryThe question is whether the Biorenery is more sustainable than CEP. This work aims to assess theenergetic-environmental performance of a Biorenery scenario in Brazil, comparing its results againstincreasing demand for ethanol, cellulosic ethanol produced by Bioreneries seems to be a viable option.Energetic-environmental assessment of

Feni Agostinho a,b,*, Enrique Ortega a

a Ecological Engineering Laboratory, Food Eng. School, State University of Campinas, Brab Programa de Ps-Graduao em Engenharia de Produo, Laboratrio de Produo e

a r t i c l e i n f o

Article history:Received 19 December 2011Received in revised form10 May 2012Accepted 13 May 2012Available online xxx

a b s t r a c t

The end of the age of chsecurity and climate chanchange at short to mediumwhich a promising sourceConventional Ethanol Plan

journal homepage: wwwAll rights reserved.

, F., Ortega, E., Energetic-env.1016/j.jclepro.2012.05.025scenario for Brazilian cellulosic ethanol

Ambiente, Universidade Paulista, Brazil

oil and global warming are causing worldwide concerns about energymitigation. Recognizing that the continuous growth paradigm will note periods, alternative energy sources to fossil fuels are being sought, ins to be that obtained from vegetal biomass. Specically in Brazil, there areCEP) using sugarcane, but due to the energy versus food debate and an

SciVerse ScienceDirect

er Production

evier .com/locate/ jc leproironmental assessment of a scenario for Brazilian cellulosic ethanol,

Nomenclature

AP Acidication PotentialCEP Conventional Ethanol PlantEROI Energy Return on InvestmentGHG Greenhouse Gas

F. Agostinho, E. Ortega / Journal of Cle2approach resulted on the Zero Emission denition (Gravitis et al.,2008), the concept that will be applied to the new ethanol plants,Bioreneries.1

The concept of biomass rening has been a subject of discussionfor more than 25 years motivated by potential for enhanced energysecurity, climate change mitigation, and rural economic develop-ment (Laser et al., 2009). Biomass energy and material recovery ismaximized when a Biorenery approach is considered, becausemany technological processes are jointly applied (Cherubini andUlgiati, 2010). Different Biorenery pathways, from feedstock toproducts, can be established according to the different types offeedstock, conversion technologies and products. Generally, thetwo technological routes are bio-chemical (enzymatic hydrolysis,and fermentation) and thermo-chemical (gasication). The choiceabout one route rather than the other depends on several aspectsincluding political, economic, social, raw material availability,market for products, infra-structure, land and water availability,and so on. There is much time before a Biorenery will be installedin Brazil and, in practical terms, Seabra et al. (2010) argues that forthe Brazilian case there is a possibility to use sugarcane residues2 toproduce more ethanol in adjacent plants of sugarcane mills alreadyinstalled.

An assessment of different aspects of a Biorenery is mandatoryfor a better decision about which technological route should bechosen, verifying their strengths and weaknesses. In this sense,several papers are being published about technological andeconomic aspects of Bioreneries (Laser et al., 2009; Cherubini andUlgiati, 2010; Luo et al., 2010; among others). On the other hand,the energetic-environmental issues are rarely discussed, and whenthey are considered, often only the Energy Return on Investment(EROI) index and the amount of CO2 released to atmosphere arecalculated. The technological and economic aspects are important,but to get a sustainable production, socio-politics and energetic-environmental issues are fundamental. Focusing on this last topic,the following doubt arises: Does the new second generationethanol plant envisaged for Brazil have better energetic-environmental performance than the current rst generation

GWP Global Warming PotentialIFEES Integrated Food, Energy and Environmental

Services productionSUMMA Sustainability Multi-Criteria, Multi-Scale

Assessmentethanol plant?The Sustainability Multi-criteria Multi-scale Assessment

(SUMMA) approach (Ulgiati et al., 2006) has been proposed as analternative evaluation technique assessing the energetic-environmental performance of products and processes. Thisapproach aims to use different methodologies with their own rules

1 Biorenery can be dened as the sustainable processing of biomass intoa spectrum of marketable products (food, feed, materials, chemicals) and energy(fuels, power, heat). This means that Biorenery can be a concept, a facility,a process, a plant, or even a cluster of facilities (de Jong et al., 2009).

2 One ton of cane stalks (or simply ton of cane) contains about 150 kg (dry) ofsugars and 125 kg (dry) of ber. Tops and leaves, called as cane trash or sugar-cane residues, represent an additional 140 kg (dry) of biomass per ton of stalks.

Please cite this article in press as: Agostinho, F., Ortega, E., Energetic-envJournal of Cleaner Production (2012), doi:10.1016/j.jclepro.2012.05.025and meanings, avoiding the generation of one over-simplied nalindicator. Moreover, the SUMMA allows decision makers to haveaccess to a range of indicators showing different aspects of thesystem instead just one or two, supporting the choice for one or theother technological route for Biorenery.

The objective of this work is to assess, through a multi-criteriaapproach, the energetic-environmental performance of a Bio-renery scenario in Brazil. Four main methodologies are used:Embodied Energy Analysis, Ecological Rucksack, EmergyAccounting and Gas Emission Inventory. Data for rst generationlarge-scale ethanol and also for the Integrated Systems of Food,Energy and Environmental Services (IFEES) production calculatedby Agostinho and Ortega (2012) are used for comparison.

2. Materials and methods

2.1. Biorenery scenario

One of the main aspects for the future development of Bio-reneries is the efcient production of transportation liquid bio-fuels. This is explained due to the increase of energy demand in thetransportation sector, and the demand for renewable fuels, whichcan only be produced from biomass (Cherubini and Ulgiati, 2010).This is a crucial point, because currently only liquid fuel for trans-portation (ethanol) is considered in almost all energy discussions inBrazil, i.e. ethanol production is the mainstream and all other co-products do not receive the same importance (except for elec-tricity production in some cases). The sustainable production ofethanol must be the target, in which a Biorenery plant is sug-gested as a potential alternative.

Specically for Brazilian case, Bonomi (2010) argues that thechoice between different technological routes for second genera-tion ethanol production must consider aspects related to eco-efciency of hydrolytic process and aspects related to operationalcosts and exibility of operational systems. Due to nancial issues,infrastructure already installed for rst generation ethanolproduction, and protable production in existing ethanol plants,a radical change in ethanol production in Brazil from short tomedium time periods is not expected. The same author suggeststhe following potential scenario for cellulosic ethanol production inBrazil: rst generation ethanol production is maintained, but thesurplus sugarcane bagasse and trash are now converted intoethanol by hydrolysis and fermentation of C6 sugars e the lignin isburned to generate steam and electricity. Still regarding the Bra-zilian case, Seabra et al. (2010) argues that for biochemicalconversion, signicant cost reductions may be achieved throughprocess integration with the conventional mill, avoiding capitalexpenses and increasing the utilization of the existing installedcapacity. For thermochemical conversion, process integration ismore difcult, but different options arise when gasication systemsare considered. In short, according to Bonomi (2010) and Seabraet al. (2010), the Brazilian scenario would entail hydrolyzingbagasse into cellulosic ethanol and steam and electricity producedby burning sugarcane trash; for this, an adjacent plant is morefeasible than an abrupt change of the current rst generationethanol plants.

A plausible scenario for a Biorenery in Brazil would be anadjacent plant to current ethanol plant that will produce cellulosicethanol from a fraction of sugarcane bagasse (see Fig. 1). Thesugarcane trash harvested will be totally burned to produce steamand electricity. The industrial processes of the adjacent plant wouldbe: (i) pre-treatment of bagasse through steam explosion andsulfuric acid, splitting the biomass into cellulose, hemicellulose andlignin; (ii) enzymatic hydrolysis to convert cellulose and hemi-

aner Production xxx (2012) 1e16cellulose into fermentable sugars (glucose C6H12O6 and xylose

ironmental assessment of a scenario for Brazilian cellulosic ethanol,

f CleF. Agostinho, E. Ortega / Journal oC5H10O5); (iii) biological fermentation of C5 and C6 sugars; (iv)ethanol distillation; (v) liquid-solid (stillage-lignin) separation; (vi)stillage feed-back to sugarcane eld as fertilizer e at long timeperiods it could be used for biogas conversion; (vii) lignin burnt toproduce steam and electricity e at long time periods it could beused as raw material for Fischer-Tropsch fuels or Hydrogen.

2.2. Sustainability multi-criteria multi-scale assessment

Decision makers need signals to inform choices betweendifferent technological routes available for Bioreneries. Thesesignals should be indicators showing different aspects of systems.Often, the analysts responsible for calculating and supplying indi-cators consider only one or two methodologies, disregarding otherimportant aspects and drawing conclusions not expressed by theindicators calculated. For instance, to choose a technological routebased only on its EROI index or on the amount of CO2 released to theatmosphere is not sufcient to determine if a system is sustainable.We believe that determining the appropriate technological route

Fig. 1. Scheme of technological route for the bio

Please cite this article in press as: Agostinho, F., Ortega, E., Energetic-envJournal of Cleaner Production (2012), doi:10.1016/j.jclepro.2012.05.025aner Production xxx (2012) 1e16 3should be based on several indicators from different methodolo-gies, in which economic, social and energetic-environmentalaspects are considered.

Methodologies used to assess the economic performance (i.e.protability, revenue, capital costs, operating cost, selling price, netpresent value, internal rate of return, and so on) are well developedand commonly applied (see for instance Laser et al. (2009), Seabraet al. (2010), Luo et al. (2010) and Clausen et al. (2010). On the otherhand, social aspects are more difcult to be evaluated because theyrequire qualitative (work conditions, quality of life, etc) and quan-titative (employment amount, income, etc) information. Unfortu-natelywewere not able to nd studies about social issues regardingBioreneries, but we believe that only small changes will occurcompared to current CEP; the only signicant change on thereduction of labor during sugarcane harvest, because it will betotally mechanized. Studies about social issues on Brazilian CEP canbe found at Mendona and Rosset (2009), Jonasse (2011), Comarand Ferraz (2008), Martinelli et al. (2011), Hall et al. (2009),Schaffel and La Rovere (2010), among others. Focusing on the

renery scenario considered in this work.


energetic-environmental performance, some efforts are beingapplied to assess the following aspects: greenhouse gas (GHG)emission, water consumption and fossil fuel consumption (Muet al., 2010; Seabra and Macedo, 2011) GHG displacement, petro-leum displacement, carbon dioxide emission, petroleum use, wateruse (Laser et al., 2009); impact categories from a Life CycleAssessment (Luo et al., 2010); exergy efciency (Ojeda et al., 2011).All of them are extremely important and must be considered ina simultaneous way. If the goal is providing a global picture ofa process impact, then a selection of many indicators is needed in

F. Agostinho, E. Ortega / Journal of Cle4order to have a comprehensive evaluation across space and timescales. In this sense, we believe that a multi-criteria approachshould be used, more specically the Sustainability Multi-Criteria,Multi-Scale Assessment (SUMMA). The SUMMA approach wasproposed by Ulgiati et al. (2006) and has been used in several LifeCycle Assessment studies. The authors choose to employ a selectionof upstream3 and downstream methods, which offer comple-mentary points of view on the complex issue of environmentalimpact assessment. Each individual assessment method is appliedaccording to its own set of rules. The calculated impact indicatorsare then interpreted within a framework in which the results ofeach method are compared.

Using SUMMA as reference, four methods were chosen to assessthe energetic-environmental performance of the Bioreneryscenario considered here: (i) Embodied Energy Analysis, (ii)Ecological Rucksack, (iii) Emergy Accounting and (iv) Gas EmissionInventory. The same methods were applied to assess the BrazilianCEP and an alternative way to produce energy, food and environ-mental services in small scale in Brazil (IFEES4; Agostinho andOrtega, 2012), whose results are used for comparison against thevalues obtained for the Biorenery scenario studied here. Thiscomparison is made through two different approaches: (i) simplenumerical comparisons considering each indicator separately (ii)and in a graphical way using a normalization approach. Thenormalization process considered here is based on the standardscore approach, in which each individual value calculated is sub-tracted by the arithmetic mean of all values and divided by thestandard deviation. The same approach was used by Ulgiati et al.(2011) assessing alternative fuels and biofuels productionprocesses. Considering that the four methodologies used heresupply many indicators and that to show all of them in a graphicalway could create confusion, the analyst might select some indica-tors according to his/her experience or according to the specictarget of the investigation. This selection should ensure the indi-cators are presented to decision-makers in the clearest manner.Once indicators are chosen, they can be normalized anddiagrammed in such a way that their values can be compared toa reference value or year, or simply viewed together, in order toprovide a global picture of the energetic-environmental systemperformance.

The four methodologies considered within SUMMA approach inthis work are described in the next sub-items. For deeper infor-mation see Agostinho and Ortega (2012) that used the same

3 The upstream methods are concerned with the inputs, and account for thedepletion of environmental resources, while the downstream methods areapplied to the output, and look at the environmental consequences of the emissions(Ulgiati et al., 2006).

4 IFEES is an acronym for Integrated Food, Energy and Environmental Servicesproduction. Basically, IFEES is a small-scale system (about 30 ha) that uses biomassas main energy sources instead petroleum, it maintains the traditional objectives ofagriculture (i.e. producing food and raw material for other systems), labor is kept in

rural areas and it produces environmental services through preserving nativevegetation. See Agostinho and Ortega (2012) for detailed explanation.

Please cite this article in press as: Agostinho, F., Ortega, E., Energetic-envJournal of Cleaner Production (2012), doi:10.1016/j.jclepro.2012.05.025methodologies and assumptions, as well as the original papersabout methodologies quoted below.

2.2.1. Embodied energy analysisEnergy Analysis is dened by International Federation of

Institutes for Advanced Study (IFIAS) as the process of deter-mining the energy required directly and indirectly to allowa system to produce a specied good or service. According toFranzese et al. (2009), embodied energy analysis aims to quantifythe availability and use of stocks of fossil fuels, sometimes alsoreferred to as commercial energy, i.e. fossil fuel and fossil-equivalent energy. Embodied energy analysis focuses on fuelsand electricity, fertilizers and other chemicals, machinery, andassets supplied to a process in terms of the oil equivalent energyrequired to produce them. Embodied energy analysis is con-cerned with the depletion of fossil energy, and therefore thoseprocess inputs of material and energy that do not require the useof fossil equivalent resources are not accounted for. Servicesprovided for free by the environment such as soil building andgroundwater recharge, are not accounted for within embodiedenergy analysis. Human labor and economic services are also notincluded in most evaluations.

Embodied energy analysis of a product or process is calculatedby summing the raw energy input multiplied by its respectiveenergy intensity factor. The more important nal indicators ofthis methodology are (i) the total amount of embodied energyconsumed by the system and (ii) its energy transformation ef-ciency reected by EROI index (Energy Return on Investment). Inthis work, considering that both agricultural and industrial pha-ses of ethanol production are accounted for, the rst index isexpressed as oil equivalent Joules per ha year (Jeq./ha/yr), whilethe EROI index is obtained by dividing the output energy (calo-ric value) by the embodied input energy. The EROI indexcalculation results in a dimensionless value representing thesystem energy efciency. Deeper understanding of EmbodiedEnergy Analysis can be found mainly at Slesser (1974) andHerendeen (1998).

2.2.2. Ecological rucksackMaterial Flow Analysis (MFA) is dened by Eurostat (2001) as

a method that assesses the efciency of use of materials usinginformation from material ow accounting. MFA helps to identifywaste of natural resources and other materials in the economythat would otherwise go unnoticed in conventional economicmonitoring systems. When dealing with the indirect materialows (upstream ows) and disregarding direct material ows(downstream ows), a subcategory of MFA is called EcologicalRucksack. The Ecological Rucksack method (Schmidt-Bleek, 1993)aims to evaluate the environmental disturbance associated withthe withdrawal of raw material from its natural ecosystem.According to Eurostat (2001), the ecological rucksack can bedened as the total sum of all materials which are not physicallyincluded in the economic output under consideration, but whichwere necessary for production, use, recycling and disposal ofindirect materials.

This methodology supplies important information related toload on environment caused generally far from system location.Appropriate rucksack factors are multiplied by each system input,accounting for the total amount of abiotic (i.e. the amount ofinorganic matter that is excavated, transported and processed perunit of energy delivered) and biotic matter, water, and air that isindirectly required by system under analysis (Ulgiati et al., 2006).Due to lack of available information about rucksack factor for aircategory, this present work considered only abiotic, biotic and

aner Production xxx (2012) 1e16water categories.


2.2.3. Emergy accountingEmergy is the available energy of one kind previously used up

directly and indirectly to make a service or product (Odum, 1996).In accordance to the second law of thermodynamics, each trans-formation process degrades the available potential energy, but thequality of the remaining energy is increased. Emergy is consid-ered a scientic measure of real wealth in terms of the energypreviously required to make something; this is recognized asa donor side approach. Deeper understanding about emergymethodology rules and meanings can be found mainly at Odum(1996) and Brown and Ulgiati (2004).

For an emergy evaluation, the system under study must rst berepresented by a systemic diagram using the symbols proposed byOdum (1996). Subsequently, all raw values of the energy and massows of system are multiplied by their respective emergy intensityvalues (see Appendix A), resulting in ows with the same unit:solar emjoules (seJ). Finally, these ows are used to calculateemergy indices (Fig. 2) and draw conclusions about energetic-

systemwere converted into their oil equivalents then multiplied by

F. Agostinho, E. Ortega / Journal of Cle(d) The emergy investment ratio (EIR F/(R N)) is the ratio ofemergy fed back from outside a system to the indigenous

Fig. 2. Aggregated diagram and emergy indices used in this work. R: natural renew-able resources; N: natural non-renewable resources; M: materials from economy; S:Services from economy; U: total emergy used by system; Tr: transformity; m-%R:modied renewability index; EYR: emergy yield ratio; EIR: emergy investment ratio;environmental aspects. A brief description of emergy indices usedin this work is given below:

(a) Transformity is dened as the solar emergy required to make1 J of a service or a product (Odum, 1996). It is obtained by theratio of total emergy that was used in a process to the energyyielded by the process (Tr U/Ep). Transformity is an expres-sion of the quality of the output itself, for the higher thetransformity, the more emergy is required to make the productow.

(b) Renewability (%R R/U) is the ratio of renewable emergy tototal emergy use. It ranges from 0 to 100%, where higher valuescorrespond to greater renewable emergy inputs from theenvironment. We considered here a modied renewabilityindex (whose acronym is m-%R; m-%R (R Mr Sr)/U), inwhich the partial renewabilities of each input were consideredfor its calculation, as proposed by Ortega et al. (2002).

(c) Emergy yield ratio (EYR U/(M S)) is the ratio of the totalemergy driving a process to the emergy imported. It isa measure of the systems ability to explore and make naturalresources available through external economic investment, andreects the potential contribution of the process to the maineconomy due to exploitation of local resources (Brown andUlgiati, 2004).m-ELR: modied environmental loading ratio; r and n subscript means respec-tively renewable and non-renewable. Based on Brown and Ulgiati (2004).

Please cite this article in press as: Agostinho, F., Ortega, E., Energetic-envJournal of Cleaner Production (2012), doi:10.1016/j.jclepro.2012.05.025the emission factors provided by the United States EnvironmentalProtection Agency (USEPA, 2008). Direct gas emissions are thosecaused by local material and fuel combustion. To estimate the directgas emissions, only diesel fuel burned in engines was accounted forthrough the emission factors for combustion in tractors fromUSEPA(2008). Both direct and indirect gas emissions supply informationabout total CO, NOx, PM10 (particles with 10 mm or less), SO2, CH4,N2O and CO2 released into the atmosphere to produce an amount ofproduct.

Additionally, the impact categories of GlobalWarming (GW) andAcidication Potential (AC) were estimated using the Jensen et al.(1997) approach. The following emission sources were notconsidered due to the lack of local emission factors data: (i)sugarcane bagasse and trash burned to produce steam and elec-tricity, (ii) sugar fermentation process, (iii) emission from soil dueto fertilizer use and (iv) land use change. Consequently, the nalvalues of GWand AP obtained in this work may be underestimated,but they are useful for comparison against the values obtained byAgostinho and Ortega (2012), since both works do not account forthe same emission sources. The same authors argue that there is noway to say what quantity of greenhouses gases released willincrease the Earths temperature to a determined degree, but GWPis important to show the quantity of greenhouses gases released byproduction systems, and may be considered as one of the mostimportant environmental parameters by decision makers. Thesame comment ts on AP, whose effects are seen as inefcientgrowth and, as a nal consequence, dieback in softwood forestsemergy inputs (both renewable and non-renewable). Itmeasures the intensity of invested emergy from the externaleconomy (Brown and Ulgiati, 2004), assessing the relationshipbetween the nonrenewable resources from the economy andnatural resources.

(e) Environmental loading ratio (ELR (N F)/R) is the ratio ofnon-renewable and imported emergy use to renewableemergy use. It indicates the pressure on the environmentproduced by the system and can be considered as a measureof ecosystem stress. According to Brown and Ulgiati (2004),ELR values lower than 2 indicate low impact on the environ-ment; values between 2 and 10 mean moderate impact; andvalues higher than 10 mean large impact. As well as foremergy renewability index, we considered in this studya modied ELR (whose acronym is m-ELR; m-ELR (N Mn Sn)/(R Mr Sr)), in which the partialrenewabilities were accounted for.

(f) Emergy Exchange Ratio (EER U/($USD*emergy-to-dollarratio)) is the ratio of solar emergy of the product sold by themean solar emergy of the money received, in which the solaremergy of the money is the market value of product times themean emergy-to-dollar ratio of the economy (3.30 1012 seJ/USD for Brazil in 2010; see Appendix A). The ratio is alwaysexpressed relative to one or the other trading partners and isa measure of the relative trade advantage of one partner overthe other (Brown and Ulgiati, 2004).

2.2.4. Gas emission inventoryGas emission inventory provides important information about

global and local emissions. This work focuses on two categories ofemission: (i) Indirect gas emissions and (ii) Direct gas emissions.Indirect gas emissions are those related to production of materialsused up by the system; those emissions are generally located farfrom the system, but nevertheless cause global environmental load.To estimate the indirect emissions, all materials used up by the

aner Production xxx (2012) 1e16 5(e.g. spruce).


3. Results and discussion

3.1. Biorenery in Brazil: a scenario approach

The main characteristics of the Biorenery scenario previouslyshown on Fig. 1 are presented on Table 1. Raw data are averagevalues from Macedo et al. (2008), Pereira and Ortega (2010) andSeabra et al. (2010). An ethanol plant producing only ethanol(instead ethanol and sugar as usual) was considered in this study;this approach does not inuence the study because the ethanol andsugar production involves processes clearly distinguished, withspecic equipment and energy use. Table 1 shows an increase onsugarcane and ethanol productivity compared to ConventionalEthanol Plant (CEP) assessed by Agostinho and Ortega (2012) (95against 87 tonwet/ha; 124.5 against 86.3 LEtOH/toncane-wet), but themain aspect is that 40% of total sugarcane trash (i.e. tops and leavesof cane plant) is now harvested to be converted into steam andelectricity, and the higher fraction of bagasse is converted intosecond generation ethanol.

Fig. 3 shows the systemic diagram of the Biorenery scenarioconsidered here, in which all input and output ows and internalfeed-backs of energy and material are represented using thesymbology proposed by Odum (1996). While Fig. 1 attempts toshow technological and yield aspects, the systemic diagram aims toshow, through a systemic view, all material and energy involvedinto the productive process, from natural or human-made sources.Basically, Fig. 1 is within Fig. 3, but system diagrams are animportant tool for integrated assessment because they providea pictorial description of the whole process, its driving forces,

F. Agostinho, E. Ortega / Journal of Cle6products recycling patterns, and interaction among components,which are all important aspects of an integrated assessment (seeBrown (2004) for detailed meaning and importance of emergydiagrams). The Biorenery depends on natural resources(symbolized by sun, wind and rain) for agricultural production,

Table 1Main characteristics of the biorenery scenario assessed in this work.

Characteristic Unit Biorenery(mill adjacent plant)

System location e So Paulo StateTime period for raw data e Scenario-2020Raw data source

(mean values)e Macedo et al., 2008;

Pereira and Ortega, 2010;Seabra et al., 2010

System areaa ha 38,750Sugarcane area ha 31,000Ethanol production capacity L/yr 267,995,000 (mill)

98,613,140(adjacent plant)

L/toncane-wet 91 (mill) 33.5(adjacent plant)

Sugarcane productivity tonwet/ha 95Mechanical harvesting % 100Crushed sugarcane tonwet /yr 2,945,000Stillage productionb Lvinasse/Lethanol 10Sugarcane bagasse kg/toncane-wet 260

tonwet/yr 765,700Sugarcane residues harvested tondry/yr (%) 156,821 (40)Sugarcane residues (mills boiler) tondry/yr 156,821Bagasse (mills boiler) tondry/yr 86,877Bagasse (adjacent plant) tondry/yr 266,522Agricultural management e Conventional

a System area sugarcane area natural vegetation area.b Stillage (Vinasse) is an ethanol production residue. It is a liquid residue with

high concentration of organic matter and nutrients that demands high levels of

oxygen to be dissolved. Large-scale vinasse is spread in the sugarcane elds asfertilizer under suitable levels of application (w140 m3 ha1).

Please cite this article in press as: Agostinho, F., Ortega, E., Energetic-envJournal of Cleaner Production (2012), doi:10.1016/j.jclepro.2012.05.025whose main objective is to produce sugarcane to be converted intoethanol, but, at the same time, the agricultural areas also produceenvironmental services; areas with natural vegetation are able toproduce higher quantity of environmental services than agricul-tural ones, but all of them have their importance. Soil conservationis another important aspect because less soil loss means lessorganic matter and nutrient loss, reducing the load on the envi-ronment, demanding less fertilizer and consequently less economicinvestments. In addition to natural resources, the Biorenery isdependent on human-made resources, mainly diesel, steel, lime,fertilizers, ammonia, enzyme and labor. Together, all energy andmatter inputs allow the Biorenery to produce ethanol and elec-tricity. The negative externalities caused by the Biorenery shouldnot be ignored as they can negatively affect the surrounding regionand also the biosphere; for instance, gas emission to atmospherefrom processes, soil run-off containing nutrients and causingeutrophication of water bodies.

Still regarding Fig. 3, harvested sugarcane is transported to theethanol plant and converted into ethanol through rst-generationprocessing. Additionally, a fraction of sugarcane trash is harvestedto be burned in boilers and generate steam and electricitysupplying the internal demand and exported to the grid. UnlikeCEP, the Biorenery scenario burns a small fraction of sugarcanebagasse (to produce steam and electricity) and the biggest fractionis used as lignocellulosic material for second-generation ethanolproduction. The byproduct lignin solid is then burned in boilers andthe liquid stillage is transported back to the sugarcane eld to beused as fertilizer. Money, represented by dashed lines, circulates onthe system (Fig. 3, right side), in which money is received by sellingproducts and used to pay for all human-made resources; it shouldbe noted that there is not money circulating into the naturalresources because they are considered innitely available and notvalued by conventional economic theory. The systemic diagram isimportant to show that all processes can only be driven through theuse of external energy and matter resources from nature andeconomy, inwhich a sustainable system cannot depend strongly onnon-renewable resources (for instance diesel), if not, there is nosense to promote it; as pointed out by Giampietro and Mayumi(2009), in some cases it is better to use diesel directly then toconvert it in another fuel.

All resources demanded by the Biorenery scenario can be seenat Table 2. The main inputs (in quantity) are water, soil loss, lime,seedlings, diesel, services and sulfuric acid. Differences comparedto the CEP (Agostinho and Ortega, 2012) are related to an increasein the use of water (1.8 times more), diesel (1.5 times more), lime(2.5 times more) and a demand for new inputs such as enzyme,sulfuric acid and diammonium phosphate. The Biorenery achieveshigh productivity of ethanol and electricity production compared toCEP: 9500 LEtOH/ha/yr vs. 6000 LEtOH/ha/yr, and 64 GWh yr1 vs.25 GWh yr1. The environmental services production, representedhere bywater inltration and CO2 absorption, have the same valuesobtained by CEP, because the total area occupied by natural vege-tationwas not changed from the previous study (7750 ha); only theinternal technological route of ethanol plant was changed fromrst- to second-generation.

Concerning the outputs, Fig. 4 shows that the Biorenery is ableto supply high amounts of ethanol and electricity to marketcompared to CEP and the small-scale system (IFEES). Even recog-nizing that the Biorenery scenario considered in this work did notreach its full potential (e.g. it could have even higher energy andmatter efciency and also produce several different by-products assuch chemicals and feed), it was able to produce about 2.6 moreelectricity and 1.6 more ethanol than the CEP. These productionindicators are important but, according to Agostinho and Ortega

aner Production xxx (2012) 1e16(2012), if the target is the sustainable development of a society,


f CleF. Agostinho, E. Ortega / Journal othen systems that are able to produce energy, food and environ-mental services (IFEES) should be also promoted. For instance,Fig. 4 shows that IFEES produces high amount of food, compost(organic matter used as fertilizer), timber wood and environmentalservices, but it makes available low amount of energy (ethanol andelectricity); on the other hand, the Biorenery and CEP are essen-tially energy suppliers. Which system should be chosen? Someargue that the evaluation of all indicators in a disconnected waycould create confusion, and that a unique indicator able tomerge allindicators should be used. For this, it could be consideredweightingfactors, but this approach is not recommended due to high level ofsubjectivity. For instance, considering the current demand ofethanol, one could give more importance for ethanol rather thanfood production, resulting in a better rating for the Biorenery andCEP rather than the IFEES. On the other hand, one could give moreimportance to food and environmental services production insteadethanol, resulting in better rating for IFEES. Due to this subjectivity,we believe that the best way is to show all indicators at the sametime, making clear the pros and cons and nally revealing whichsystem is better for the interests of society.

The amount of ethanol, electricity and other materials producedare important as indicators to help decision-makers but not enoughto promote a system. What are the economic, social and energetic-environmental costs for this high productivity? All these aspectsmust be considered simultaneously before to choose the betteroption.

Fig. 3. Systemic diagram of the bio

Please cite this article in press as: Agostinho, F., Ortega, E., Energetic-envJournal of Cleaner Production (2012), doi:10.1016/j.jclepro.2012.05.025aner Production xxx (2012) 1e16 73.2. Energetic-environmental assessment

3.2.1. Performance for overall system: hectare year as functionalunit

Table 3 shows the overall systems rating obtained from theSUMMA approach. Conrming our expectations, the Bioreneryscenario is able to produce annually a high amount of grossenergy (2.31 1011 J/ha/yr), a value about 60% higher thanConventional Ethanol Plant (CEP) and 112% higher than small-scale system (IFEES). This could be considered as an excellentindicator for energy efciency, but it is recognized that high net(and renewable) energy rather than high gross energy is thetarget.

3.2.1.1. Embodied energy indices. Energy efciency is usuallyexpressed by an output/input energy relationship, the EnergyReturn on Investment (EROI) index. It measures the systemscapacity to transform one kind of energy into another, in whichhigh values mean high efciency. Table 3 shows that the overallenergy efciency (EROI) for the Biorenery is 4.3, a similar valueobtained by the CEP (4.6); this indicates that 4.3 units of one kind ofenergy become available for each unit used up by the Biorenery.IFEES has an EROI of 13.2, showing net energy efciency about 3times higher than the Biorenery and CEP; it must be highlightedthat this efciency reects all energy output, including ethanol,food, forestry products and compost. Additionally, the IFEES

renery assessed in this work.


Table 2Inputs and outputs of the biorenery scenario assessed in this worka.

Item Unit Value

Input

#1 e Sun kWh/m2/day 5.00#2 e Rain m3/m2/yr 1.40#3 eWind m/s 4.70#4 eWater kg/ha/yr 174,080.00#5 e Soil loss kg soil/ha/yr 13,328.00#6 e Concrete kg/ha/yr 1.14#7 e Steel kg/ha/yr 11.31#8 e Copper (heat transfer) kg/ha/yr 0.56#9 e Rubber (tractor tire) kg/ha/yr 2.51#10 e Lime kg/ha/yr 1600.00#11 e Nitrogen kg/ha/yr 63.70#12 e Phosphorus kg/ha/yr 43.20#13 e Potassium kg/ha/yr 110.00#14 e Diesel L/ha/yr 350.00#15 e Seedlings kg/ha/yr 2800.00#16 e Herbicide kg/ha/yr 1.76#17 e Insecticide kg/ha/yr 0.13#18 e Enzyme (adjacent plant) kg/ha/yr 86.00#19 e Lime (adjacent plant) kg/ha/yr 336.00#20 eWater (adjacent plant) kg/ha/yr 26,200#21 e Sulfuric acid (adjacent plant) kg/ha/yr 461.00#22 e Diammonium phosphate (adjacent plant) kg/ha/yr 21.60#23 e Corn steep liquor (adjacent plant) kg/ha/yr 172.87#24 e Labor h/ha/yr 70.20

F. Agostinho, E. Ortega / Journal of Cle8#25 e Services USD/ha/yr 585.00Output#26 e Ethanol L/ha/yr 9461#27 e Electricity kWh/yr 64,053,750Environmental services:#28 eWater inltration Lwater/ha/yr 840,000#29 e Potential carbon dioxide absorbed kgCO2/ha/yr 6776

ademands annually about 3.8 times less energy per hectare than CEP,and about 6.5 times less than the Biorenery.

3.2.1.2. Emergy indices. Focusing on the overall emergy efciency(higher transformities represent lower system efciency), Table 3shows the Biorenery with better rating compared to other two

Fig. 4. Radar diagram comparing total energy and matter produced by three differentsystems. Biorenery data from Table 2; data for conventional ethanol production andIFEES (integrated food, energy and environmental services production) systems fromAgostinho and Ortega (2012).

See Appendix B detailed calculation.

Please cite this article in press as: Agostinho, F., Ortega, E., Energetic-envJournal of Cleaner Production (2012), doi:10.1016/j.jclepro.2012.05.025systems e Biorenery 58,000 seJ/J, IFEES 61,000 seJ/J and CEP with71,000 seJ/J. It means that the Biorenery demands about 5% lessemergy to make available the same amount of gross energy outputcompared to IFEES and 22% compared to CEP. For comparison, theTransformity for gasoline and diesel is about 184,000 seJ/J (Brownet al., 2011), showing that all three systems assessed have higheremergy efciency than gasoline and/or diesel. Transformity valuesare quite different from that obtained by EROI index, because EROIshowed a better performance for IFEES. This happens becauseTransformity is an input/output ratio that includes all hidden costs(natural resources and labor through a large-scale view) notconsidered in an embodied energy analysis; this explains whyemergy efciency index differs from EROI.

Renewability index shows a lower renewability index for theBiorenery (m-%R 19%) compared to CEP (24%) and IFEES (54%).This low renewability was not a surprise because the Bioreneryscenario considered here is not representative of a denitive Bio-renery per se, i.e. a small-scale industrial production aiming toproduce several by-products from renewable biomass energysource. The Biorenery considered here aims exclusively toincrease ethanol and electricity production using sugarcane trashas biomass source. High productivity was reached, but an increasein material and energy demand was also increased. This charac-teristic is expressed by the low renewability, indicating an unsus-tainable scenario for the Biorenery assessed here. For comparison,Pereira and Ortega (2010) obtained 31% renewability for a Braziliansugarcane ethanol while Felix and Tilley (2009) obtained 21% forswitchgrass cellulosic ethanol in USA. Brazilians agrochemicalagriculture has values ranging from 20 to 42% while ecologicalmanagement values range from 56 to 73% (Agostinho et al., 2010;Cavalett and Ortega, 2010, 2009). Since non-renewable resources(derived from petroleum and mineral ores) are the driving forces ofcurrent large-scale ethanol production, their depletion over thenext decades will be a great challenge for those productionsystems.

EYR shows better values for IFEES, because about 44% (EYR of2.27) of its total emergy comes from external economic resources,while for the CEP and Biorenery systems this percentage is about66% and 72%, respectively. This shows that the dependency oneconomic resources (non-renewable resources) supporting the CEPand Biorenery systems is high. In addition to the dependence ofexternal economic resources, EYR also shows the potential contri-bution to the economy due to the exploitation of local resources; forthe Biorenery and CEP, this means that about 1.39 and 1.52 timesmore emergy become available to society by each emergy investedfrom economy, respectively, while for the IFEES this number isabout 2.27. We must be aware that these EYR values can only beconsidered a positive aspect if the modied renewability index (m-%R) reaches values closer to those obtained by ecological agricul-tural management (i.e. at least higher than 50%). Thus, a value of2.27 found for IFEES can be considered as good value, because ithas a m-%R of 54%making it able to supply renewable energy to theeconomy; on the other hand, a m-%R of 19% and 24% obtainedrespectively by the Biorenery and CEP show that the majority ofemergy supplied to the economy comes from non-renewableresources. For comparison, EYR values ranging from 1.34 to 2.17are typical for agrochemical Brazilians agriculture, while ecologicalmanagement has values from 2.24 to 3.69 (Agostinho et al., 2010;Cavalett and Ortega, 2010, 2009). Pereira and Ortega (2010)obtained an EYR of 1.57 for Brazilian sugarcane ethanol whileFelix and Tilley (2009) obtained an EYR of 1.29 for switchgrasscellulosic ethanol in USA. An increase of indigenous renewableinputs rather than economic ones is extremely important becausehigh use of renewable resources will be advantageous in a future

aner Production xxx (2012) 1e16scenario of oil scarcity.


Bi(th

2.3

4.35.3

5819191.31.32.52.54.20.91.3

1565

tpun in

f CleFocusingonEIR, IFEEShasbetter value (1.42) compared toCEPandBiorenery systems (1.92 and 2.59 respectively). This indicates thatfor each unit of energy from nature used up by IFEES, 1.42 units ofenergy are necessary from the economy. Inversely, if CEP is chosen asa supplier of ethanol and electricity, then it will supply 0.52 emergyunits per each emergy unit invested from economy; for the Bio-renery this ratio is 0.39. Thus we can say that CEP has better ratingfor EIR than the Biorenery, but only because its m-%R of 24%, higherthan the 19% obtained by the Biorenery. For comparison, Brazilsagrochemical agriculture has values ranging from 0.85 to 2.95, whilefor an ecological management, EIR ranges from 0.37 to 0.80(Agostinho et al., 2010; Cavalett and Ortega, 2010, 2009). Regardingbiofuel production, Felix and Tilley (2009) obtained an EIR of 3.42 for

Table 3Embodied energy, emergy accounting and gas emission indicesa.

Methodologies and their indices Unit

Total energy output J/ha.yrEmbodied energyEROI e Energy return on investment eGross energy requirement MJeq.oil/ha.yr

Emergy accountingTr e Transformity seJ/Jm-%R e Renewabilityc %m-%R e Renewabilityc, d eEYR e Emergy yield ratio eEYR e Emergy yield ratiod eEIR e Emergy investment ratio eEIR e Emergy investment ratiod em-ELR e environmental loading ratioc eEER e Emergy exchange ratio eU e Total emergy seJ/ha.yr

Gas emissionGlobal warming potential kg CO2-eq./ha/yrAcidication potential kg SO2-eq./ha/yr

a Observation: These indices correspond to the systems as a whole, not for one oub Agostinho and Ortega (2012) updated; Conventional sugarcane ethanol productio

Services production in small-scale.c Considering partial renewability of each systems input.d Without accounting for internal labor (only the IFEES has internal labor).

F. Agostinho, E. Ortega / Journal oswitchgrass cellulosic ethanol and Ulgiati (2001) obtained an EIR of12.06 for corn ethanol in USA. The use of ecological management onagricultureanda reductionof thedependenceoneconomic resourcesare necessary to increase the systems ability to use local renewableresources with low external investment.

According to a previous denition by Brown and Ulgiati (2004),ELR results in Table 3 show a low load (stress) on environmentcaused by IFEES (0.85) due to transformation activity, while CEPand Biorenery systems causemoderate (3.10) and high (4.29) load,respectively. It must be noted that this load is a reection of thesystems dependence on non-renewable resources and does notrepresent the direct environmental impact downstream; as previ-ously explained, Emergy Methodology is a donor side approach.For a simple comparison, m-ELR values ranging from 1.40 to 4.18are typical for agrochemical-dependent Brazilian agriculture, whileecological management has values from 0.37 to 0.84 (Agostinhoet al., 2010; Cavalett and Ortega, 2010, 2009). Regarding biofuelproduction, Felix and Tilley (2009) obtained an ELR of 3.87 forswitchgrass cellulosic ethanol, Ulgiati (2001) obtained an ELR of17.65 for corn ethanol in USA, and Pereira and Ortega (2010)obtained a m-ELR of 2.23 for Brazilian sugarcane ethanol.

The average EER value of 0.93 obtained by the Biorenery andIFEES indicate that they are receiving more emergy when sellingproducts than the total emergy used up in the production. Itmeans that there is an emergy advantage for producers. On theother hand, CEP with an EER of about 1.14 indicates that it isdelivering more emergy than receiving back in the trade

Please cite this article in press as: Agostinho, F., Ortega, E., Energetic-envJournal of Cleaner Production (2012), doi:10.1016/j.jclepro.2012.05.025operation, i.e. it has an emergy disadvantage. According to Odum(1996) (see also Cuadra and Rydberg (2006)), EER value could beused as a parameter to assess the market price of any good orservice. Considering this approach, the market price of productssold by CEP should be increased, while the market price ofproducts sold by the Biorenery and IFEES should be reduced toreach emergy equilibrium.

3.2.1.3. Global warming and acidication potential. Table 3 showsa Global Warming Potential (GWP) of 15.5 tonCO2-eq./ha/yr for theBiorenery, while CEP and IFEES have 14.1 and 1.6 tonCO2-eq./ha/yr,respectively. This indicates that the Biorenery has higher potentialto increase global warming. On the other hand, the IFEES has

oreneryis work)

Conventional ethanol plant (CEP) b IFEESb

1E11 1.45E11 1.09E11

3 4.61 13.223E04 3.15E04 8.23E03

,300 71,500 61,30024 5424 52

9 1.52 1.709 1.52 2.279 1.92 1.429 1.92 0.799 3.10 0.853 1.14 0.944E16 1.03E16 6.67E15

,745.78 14,075.59 1644.40.89 59.42 2.95

t alone.large-scale; IFEES is an acronym for the Integrated Food, Energy and Environmental

aner Production xxx (2012) 1e16 9a potential about 9 times lower than the other two systems, indi-cating a much better rating. Still regarding Table 3, it is observed anAP of 66 kg SO2-eq./ha/yr for the Biorenery while CEP and IFEESsystems have 59 and 3 kg SO2-eq./ha/yr, respectively. The sametendency showed by GWP is seen here for AC, in which the Bio-renery has the worst rating followed by CEP. On the other hand,the IFEES has an AP about 20 times lower than both.

As explained before, this work considers the emissions relatedto diesel burned directly by agricultural engines (local emissions)and the indirect emissions related to the burn of heavy oil inindustrial boilers to make the materials an energy consumedavailable for the Biorenery (regional or global emissions). Thus,a better rating for the IFEES compared to other systems wasexpected, because it demands a lower amount of goods fromeconomy, consuming about 9 times less diesel and 30 times lesslime (in mass units per hectare per year) than the Biorenery. Onthe other hand, contrary to the expected, the Biorenery demandsa higher amount of diesel (1.5 times higher) and lime (2.5 timeshigher) than CEP, resulting in aworse performance for GWP and AP.This rating is inverted comparing CEP and the Biorenery, when thefunctional unit changes from ha year to mass of ethanol produced,justied by the higher ethanol productivity for Biorenery than CEP(124.5 against 86.3 LEtOH/toncane); this issue is discussed in detail onthe next sub-item. Other interesting result is that about 60% of theGWP and AP for all three systems assessed are due to indirectemissions, usually not perceived by society, potentially hidingimportant sources of environmental burden.


3.2.1.4. A joint view. Selected indicators from Table 3 were dis-played in a radar diagram (Fig. 5) in order to put data with differentorders of magnitude together and provide visibility to the perfor-mance of the different systems. Those indicators plotted on Fig. 5were chosen beyond all others because climate change mitigationand energy efciency are the main driving forces for future Bio-reneries. The large area on Fig. 5 indicates a worse performance,i.e. identies the system that is characterized by the largestpotential impact and lesser energy efciency. Among the threesystems, the Biorenery has the worst performance in almost allindicators (only its Transformity is better compared to other twosystems), suggesting that the Biorenery scenario assessed hereshould not be promoted considering only the performance of thesystem as a whole. CEP has similar performance for EROI, GWP andAC compared to the Biorenery, but its renewability and environ-mental loading ratio shows better values. Fig. 5 suggests that IFEESis the best option, because only its emergy efciency is lower thanthe Biorenery.

3.2.2. Performance of ethanol produced: mass as functional unitIn contrast to the previous section where all production was

accounted for, now only the amount of ethanol produced is

F. Agostinho, E. Ortega / Journal of Cle10considered as functional unit (Table 4). Recognizing that all systemsproduce more than just ethanol, the allocation procedure in energyunits adopted by Agostinho and Ortega (2012) was considered inthis work to allow comparisons.

The embodied energy required to produce 1 kg of ethanol(1 kg 1.25 L) by the Biorenery (6.86 MJ) is similar to valueobtained by CEP (6.44 MJ), but about 3 times greater than the valueget by IFEES (2.24 MJ). This is reected by the EROI index, in whichfor each Joule consumed by the Biorenery, 4.33 J of ethanol areproduced; for Conventional Ethanol Plant (CEP) and IFEES systems,this relationship is 1:4.61 and 1:13.2 respectively. These numbersindicate that ethanol produced by the Biorenery scenarioconsidered in this work has the lowest net energy efciencycompared to other two systems. For comparison, EROI values forBrazilian CEP found in literature are 3.7 (Oliveira et al., 2005), 9.3(Macedo et al., 2008), 9.0 (Smeets et al., 2008) and about 8.2(Pereira and Ortega, 2010). Corn ethanol has an EROI about 1.14(Oliveira et al., 2005; Ulgiati et al., 2011) while switchgrass ethanolin USA has an EROI of 2.62 (Felix and Tilley, 2009).

Fig. 5. Radar diagram with selected indicators for three assessed system. Biorenerydata from Table 3; data for conventional ethanol production and IFEES (integrated

food, energy and environmental services production) systems from Agostinho andOrtega (2012).

Please cite this article in press as: Agostinho, F., Ortega, E., Energetic-envJournal of Cleaner Production (2012), doi:10.1016/j.jclepro.2012.05.025Regarding the Ecological Rucksack method, Table 4 showsa huge advantage for ethanol produced by IFEES compared toBiorenery scenario and CEP, because IFEES demands in average 3times less abiotic material (non-organic material), 2 times lessbiotic material (organic material) and 10 times less water toproduce 1 kg of ethanol. Comparing the Biorenery against CEP, thelatter demands about 40%more abiotic material, bioticmaterial andwater. Ulgiati et al. (2011) found the following values for cornethanol in USA: 7.45 kgabiotic/kgEtOH, 0.35 kgbiotic/kgEtOH and4811 kgwater/kgEtOH. Regarding water consumption, Stone et al.(2010) obtained a demand of 2580 kgwater/kgEtOH from corn,580 kgwater/kgEtOH from sugarcane and 1980 kgwater/kgEtOH fromswitchgrass.

The specic emergy shows that the Biorenery is about 1.2times more efcient than CEP and 19.4 times more efcient thanIFEES if only ethanol is taken into account. To produce 1 kg ofethanol are necessary 1.78 1012 seJ by the Biorenery, while CEPand IFEES systems demand 2.16 1012 seJ and 3.45 1013 seJrespectively. Some Transformity values found in literature for fuelsare: 110,000 seJ/J for switchgrass ethanol production (Felix andTilley, 2009); 151,000 seJ/J for methanol from wood (Ulgiati,2001); 189,000 seJ/J for ethanol from corn (Ulgiati et al., 2011);187,000 seJ/J for gasoline, 178,000 seJ/J for natural gas and181,000 seJ/J for Diesel (Brown et al., 2011). These values indicatethat ethanol produced by the Biorenery (59,900 seJ/J) is the bestoption if only emergy efciency is considered as the decisionparameter, followed by ethanol from CEP (72,700 seJ/J), switchgrassethanol, methanol from wood and so forth. As observed byAgostinho and Ortega (2012), the value obtained by IFEES ismisleading because it produces several products in addition toethanol. Emergy evaluation does not allow an allocation procedure,thus the high heat value of ethanol produced by IFEES was dividedby total emergy used by IFEES as a whole (including all products),resulting in low efciency. On the other hand, the Biorenery andCEP are specialized in ethanol production, and thus all emergyinputs are used up to produce basically ethanol; for these systems,the Transformity index shows the real emergy efciency for ethanolproduction. A fair comparison should be made considering thesmall-scale system producing only ethanol, but the intentions ofthe IFEES are more varied, preventing it from being considered anexclusive ethanol production system.

In reference to gas emissions, ethanol produced by IFEESreleases less gas compared to the Biorenery and CEP (Table 4). Themain differences are in CH4, CO, and PM10 emissions, in which theBiorenery and CEP release about 4,000, 133, and 44 times morethan IFEES, respectively. Disregarding the hydrocarbons, in whichthe Biorenery and CEP systems release about the same amountper ton of ethanol produced, in average the Biorenery releases 50%less gas than CEP. This is reected on impact categories, where CEPhas about 43% more potential to cause Global Warming and Acid-ication than the Biorenery per ton of ethanol produced. Forcomparison, Ulgiati et al. (2011) estimated a GWP of 2020 kgCO2-eq./ton of ethanol from corn, a similar value obtained here for sugar-cane ethanol (2026 kgCO2-eq./ton for the Biorenery and2882 kgCO2-eq./ton for CEP). Considering solely gas emissions as thejudgment parameter, the ethanol produced by IFEES should bestrongly promoted instead the Biorenery and CEP.

Fig. 6 shows the radar diagram considering some indices fromTable 4. Again, due to the climate change and fossil fuel replacementconcerns, the indices related to those issues were displayed, but wedecide to add two indices related to water and abiotic materialconsumption. Even though these two indicators did not reach thesame level of concern compared to climate change and fossil fuelissues, we believe that at short to medium time periods society will

aner Production xxx (2012) 1e16face problemswithwater andmaterial availability. The large area on


allocation issue as previously commented. Assuming that all indi-

Table 4Environmental impact indices per unit of ethanola.

Methodologies and their indices Unit Biorenery

Embodied energyEnergy intensity MJ/kgEtOH 6.8EROI e 4.3

Ecological rucksackAbiotic material consumption kgabiotic/kgEtOH 3.7Biotic material consumption kgbiotic/kgEtOH 0.1

Water consumption kgwater/kgEtOH 248.0Emergy accountingSpecic emergy (with L&S)c seJ/gEtOH 1.78E09Specic emergy (without L&S) seJ/gEtOH 1.44E09Transformity (with L&S) seJ/JEtOH 5.99E04Transformity (without L&S) seJ/JEtOH 4.84E04

Gas emissionHydrocarbons releasedd g hydr./tonEtOH 218.8Carbon monoxide released g CO/tonEtOH 84,557.7Nitrogen oxide released g NOx/tonEtOH 6944.9Particulate matter released g PM10/tonEtOH 17,850.9Sulfur dioxide released g SO2/tonEtOH 2368.9Methane released g CH4/tonEtOH 8877.3Nitrous oxide released g N2O/tonEtOH 236.2Carbon dioxide released g CO2/tonEtOH 1,271,580.1Global warming potential kg CO2-eq./tonEtOH 2026.4Acidication potential g SO2-eq./tonEtOH 8480.4

a Allocation in energy units.b Agostinho and Ortega (2012) updated; Conventional ethanol plant in large-scale;

production in small-scale.c L&S means Labor and Services.

F. Agostinho, E. Ortega / Journal of CleFig. 6 indicates worse performance. Through an overall view, theBiorenery has an advantage compared to CEP. On the other hand,while the Biorenery uses less amount of abioticmaterial andwater,and causing less global warming per kilogram of ethanol produced,it has lower energy efciency (i.e. CEP is able to produce moreethanol through the use of the same amount of energy). The IFEESshowed better values compared to other two systems: it is able to

d Assuming CH2 as a basic hydrocarbon.produce 1 kgof ethanol demanding lesswater, abioticmaterial, withlower GWP and higher energy efciency, but it demands a high

Fig. 6. Radar diagram with selected indicators representing the ethanol produced bythree different systems. Biorenery data from Table 4; data for conventional ethanolproduction and IFEES (integrated food, energy and environmental services production)systems from Agostinho and Ortega (2012).

Please cite this article in press as: Agostinho, F., Ortega, E., Energetic-envJournal of Cleaner Production (2012), doi:10.1016/j.jclepro.2012.05.025cators on Fig. 6 have the same weight during a decision, it is sug-gested that IFEES is the best option.

3.3. General discussionamount of emergye the reader should remember that this is due to

(this work) Conventional ethanol plant (CEP) b IFEESb

6 6.44 2.243 4.61 13.22

6 4.91 1.507 0.24 0.114 373.05 29.80

2.16E09 3.45E101.63E09 2.21E107.27E04 1.16E065.50E04 7.46E05

6 228.38 54.467 134,060.86 817.063 9756.12 790.716 28,339.24 520.950 3583.26 109.570 14,120.38 2.779 372.24 13.645 1,684,051.03 442,856.017 2882.67 448.464 12,168.65 805.39

IFEES is an acronym for the Integrated Food, Energy and Environmental Services

aner Production xxx (2012) 1e16 11First, the reader must be aware that the Biorenery consideredin this work is not a commercial plant, rather it is a plausiblescenario considering current tendencies in Brazil commented bysome authors and assumed by us. Raw data and intensity factorsused here were extracted from literature and, of course, the use ofone reference rather than the other can produce different results.Even being considered important, a sensitivity analysis was notperformed in this work because the scenario considered for theBiorenery is very specic and basically its raw data came fromonly two papers, thus there is not a range of different raw dataavailable that could change the nal results. Moreover, the perfor-mance indices obtained for the Biorenery assumed here werecompared to other two systems assessed through the same meth-odologies and intensity factors; thus, the potential source of errorsbelong to all three systems. One important aspect that deservesrenement is the intensity factor for enzyme industrial productione the Biorenery scenario assumes that enzyme comes fromoutside system boundaries. The intensity factor of chemicals wasconsidered for enzyme (see Appendix A).

All indices obtained here for the Biorenery scenario werecompared to the other two different systems assessed previously byAgostinho and Ortega (2012): the Conventional Ethanol Plant (CEP)and the Integrated Food, Energy and Environmental Services(IFEES) production. Generally, the results can be divided into threeparts: (i) focusing on total production; (ii) focusing on overallsystems performance; (iii) focusing on ethanol production.

(i) Regarding total production, the Biorenery is the best option ifthe gross energy production is the target. On the other hand,


f CleIFEES is able to produce large amounts of food, wood, compostand environmental services, but its ethanol productivity isabout 25 lower than CEP and 40 times lower than theBiorenery.

(ii) Recognizing that strong sustainability is mandatory for anyeconomy and that the energetic-environmental aspects areimportant pillars of sustainability concept, assessing thesystems performance as a whole is essential to the establish-ment of public policies for medium to long time periods. Thisapproach aims to show that high productivity at any cost is nolonger a winner strategy for sustainable economies. Theindicators obtained show that IFEES has an EROI about 3 timeshigher than the Biorenery and CEP, and it also demands 5times less energy per ha year. Additionally, IFEES hasa renewability of 55% against 20% for Biorenery and 26% forCEP, its GWP and AP are about 9 and 21 times less than theBiorenery and CEP. These numbers show that IFEES should bepromoted to reach strong sustainability. The CEP has betterrating than the Biorenery in almost all indicators, except forgross energy output and Transformity. We believe that theenergetic-environmental viability of cellulosic ethanol fromsugarcane obtained from the Biorenery scenario consideredin this work is questionable because it had the lowest energynet yield and it relies upon non-renewable resources in itsprocesses.

(iii) Focusing on ethanol production, the IFEES has higher EROI andit also demands about 3 times less energy to produce 1 kg ofethanol. Additionally, IFEES demands low material consump-tion and releases low amount of gases to atmosphere per massof ethanol produced. On the other hand, the Transformity ofIFEES shows emergy efciency about 18 times lower than theBiorenery and CEP. The Biorenery has better values forwater consumption, abiotic and biotic material demand, and italso releases lesser amount of gases to atmosphere comparedto CEP, but its net energy efciency is slightly lower than CEP.

Coming back to the research question (Does the new secondgeneration ethanol plant envisaged for Brazil has better energetic-environmental performance than the current rst generationethanol plant?), we would say that still there is not a denitiveanswer. As demonstrated in this paper, there are many aspectsregarding the environmental-energetic systems performance thatmust be considered. Someone can say that a specic aspect (rep-resented by an index) is more important than the other, but thisapproach is always based on subjectivity. Recognizing that there isnot a unique and magic indicator able to show the systemperformance fairly, and that may be a system will never be able toreach better rating for all indices, the radar diagrams aims to showwhich systems possess better overall rating. Considering thesystem as whole, Fig. 5 suggests that we would say NO to theresearch question, i.e. the Biorenery does not have betterenergetic-environmental performance than CEP. On the other hand,considering only the ethanol output as functional unit (Fig. 6), wewould say YES, ethanol produced by the Biorenery has betterenergetic-environmental rating than CEP (this is a characteristic ofeconomy of scale). Which system should be promoted? We believethat this decision depends strongly on the socio-economic devel-opment that politicians and society desires for the future of theirNation. If ethanol production is the target, then the Bioreneryshould be promoted, but this will reduce the carrying capacity ofthe Biosphere (i.e. fewer stocks of material and energy will beavailable and the capacity to absorb the impacts will be reduced). IfCEP is promoted, the ethanol production will remain on lowerlevels than supplied by the Biorenery, but the load on environ-

F. Agostinho, E. Ortega / Journal o12ment from a global scale viewwill also be lower than caused by the

Please cite this article in press as: Agostinho, F., Ortega, E., Energetic-envJournal of Cleaner Production (2012), doi:10.1016/j.jclepro.2012.05.025Biorenery. We believe that IFEES should be promoted instead ofBiorenery or CEP, or even a combination of them, because IFEEShas better rating for the majority of indices assessed here, and asexplained by Agostinho and Ortega (2012), it also aims for a para-digm change about socio-economic development. According toSanta Barbara (2007), a new way of looking at quality of life isdemanded instead just more engineering. Not just more economicdevelopment, but a new sense of genuine global cooperation. Notjust pursuing the chimera of nationalistic energy security, buta new paradigm based on social justice and ecologicalsustainability.

Results show the existence of a trade-off, in which eachproduction system has better value for determined performanceindex rather than other. We believe that we will rarely seea perfect system with high performance in all aspects (i.e.economic, environmental, energetic and social). According toGalembeck (2010), careful attention is continually needed to avoidthe environmental and social problems that will arise if short-term economic benets receive priority over sustainableproduction objectives. A production system must be chosen, butthis choice must consider the opinion of experts in differentknowledge elds and also the general society, avoiding a decisionbased on desires of few people with political and economicinuence.

4. Conclusions

Considering the methodologies and assumptions of this work,the follow conclusions can be drawn:

(a) Regarding total systems production e The Biorenery is able toproduce 1.57 times more ethanol than Conventional EthanolPlants (CEP) and 40 times more than IFEES. Moreover, itselectricity production is 2.58 times higher than CEP. On theother hand, IFEES also produces food, wood, compost andenvironmental services instead only ethanol.

(b) Regarding the energetic-environmental performance fora system as a whole e Disregarding Transformity index, theIFEES had better performance for all other indicators comparedto the Biorenery and CEP. Concerning large-scale systems,while the Biorenery and CEP have similar net energy ef-ciency (EROI of 4.33 and 4.61), the Biorenery has betteremergy efciency (58,300 versus 71,500 seJ/J). On the otherhand, Global Warming and Acidication Potential of the Bio-renery are 11% higher than CEP, it also has higher load onenvironment (ELR of 4.29 versus 3.10) and lower renewability(19% against 24%).

(c) Regarding the energetic-environmental performance per unitof ethanol produced e Excluding Transformity, the IFEES hasbetter rating for all other indicators. Concerning large-scalesystems, the energy demand is similar for both (w6.6 MJ/kgE-tOH), but all other indices showed a better rating for the Bio-renery: to produce 1 kg of ethanol, the Biorenery requires 1.5times less water and 1.3 times less abiotic material than CEP, itsGWP and AC are about 43% lower and its emergy efciency is21% higher than CEP.

The nal indicators show that Biorenery scenario has betterrating than CEP for some aspects but worse for others; a systemwith better performance for all indicators is rare. One systemshould be promoted instead another depending on objectives, forinstance, the Biorenery is the best option if an increase in ethanolproduction is the target, but a more sustainable ethanol produc-tion is obtained through IFEES followed by CEP and the

aner Production xxx (2012) 1e16Biorenery.


The use of biomass as an energy source is not enough to ensurea prosperous future for later generation; the biomass must beproperly produced and manufactured through low dependence onfossil fuel derivates. The ethanol produced by large-scale systemsassessed here cannot be considered as a renewable energy source(neither as sustainable), they are energy consuming processes thatprovide a means for converting high amount of water, soil, fossilfuel, minerals, and other resources into ethanol liquid fuel. On theother hand, the IFEES is a better alternative when sustainabilityissues are considered as the mainstream within political discus-sions about economic growth. The results show that if the ethanolproduced by the Biorenery scenario assessed here is pushed bythe political subsidy for biofuels, it will only accelerate the rate atwhich fossil fuel and other important materials (e.g. water, soil, ironore converted into steel, and so on) are being depleted. Neverthe-less, a complete Biorenery (i.e. producing several different by-products as chemicals, fertilizers, feed, etc) seems to be the bestoptionwhen dealing with strong sustainability, but its performanceneeds to be assessed by the same methodologies considered in thispresent work and others related to social-political and economicissues.

Acknowledgements

Feni Agostinho is grateful to Fundao de Amparo Pesquisa doEstado de So Paulo (FAPESP, process number 2009/51705-9) forgranting the Post-Doctoral scholarship that helped make this workpossible. Special thanks to BrandonWinfrey for his work on Englishlanguage revision.

Appendix B. Raw data calculation for Table 2

Note#1 (Sun) e Solar radiation 5 kWh m2 day1 (www.cresesb.cepel.br); Albedo 20% (Odum, 1996);Conversion (kWh/m2/yr) (1 e Albedo) (10,000 m2 ha1)(3,600,000 J kWh1) (365 days yr1); Input ow 5.26 1013 J/ha/yr.

Note#2 (Rain) e Rainfall 1.4 m3 yr1 (www.sirgh.sp.gov.br);Gibbs free energy 5000 J kg1 (Odum, 1996); Waterdensity 1000 kg m3; Conversion (m3/m2/yr) (J/kg) (kg/m3)(10,000 m2 ha1); Input ow 7.00 1010 J/ha/yr.

Note#3 (Wind) e Air density 1.3 kg m3; Average of annualvelocity 4.7 m s1 (www.cptec.inpe.br); Geotropicwind 2.82 m s1 (assumed as 60% of annual velocity (Rodrigueset al., 2002); Drag coefcient 0.001 (Rodrigues et al., 2002);Conversion (kg/m3) (m/s)3 (0.001) (10,000 m2 ha1)(31.56 1006 s/yr); Input ow 9.20 1009 J/ha/yr.

Note#4 (Water) e Water consumption of 18.4 Lwater/Lethanol or1.6 m3 water/ton crushed sugarcane (Pereira and Ortega, 2010). Itincludes only industrial phase, because sugarcane irrigation in SaoPaulo State is used only in special cases due to excellent climateconditions. Ethanol produced 366,608,140 L yr1 (see Note#25).Gibbs free energy 5000 J/kgwater (Odum, 1996);Conversion (Lwater/Lethanol) (Lethanol/yr) (1 kgwater/Lwater) (J/kgwa-ter) (1/38,750 ha); Input ow 174,080 kg ha1 yr1 or8.70 1008 J/ha/yr.

Note#5 (Soil loss; organicmatter)e Average value for soil loss ofconventional sugarcane production 11,900 kgsoil/ha yr (Pereiraand Ortega, 2010); It was assumed an increase of 40% for soil lossfor biorenary, due to harvest of 40% in mass of cane trash. In the

bod

Wind 2.45 10 seJ/J e04 C

00000400400080

70400051

02;icalil wmed

F. Agostinho, E. Ortega / Journal of Cleaner Production xxx (2012) 1e16 13Water 6.89 10 seJ/J eSoil loss 1.24 1005 seJ/J D eConcrete 2.42 1012 seJ/kg E 16Steel 3.78 1012 seJ/kg C 10Cooper 3.36 1012 seJ/kg C 15Rubber 7.22 1012 seJ/kg F 20Lime 1.68 1012 seJ/kg C 22Nitrogen 7.28 1012 seJ/kg G 14Phosphorus 5.67 1012 seJ/kg D 26Potassium 1.85 1012 seJ/kg A 16Diesel 1.81 1005 seJ/J H 15Seedlings 1.41 1011 seJ/kg I 38Herbicide 2.49 1013 seJ/kg C 56Insecticide 2.49 1013 seJ/kg C 47Enzyme 2.65 1012 seJ/kg J 32Diammonium phosphate (N) 1.59 1013 seJ/kg D 12Corn steep liquor (heat) 5.54 1008 seJ/kg K 16Sulfuric acid 1.53 1011 seJ/kg D 50Labor 7.21 1012 seJ/h C eBrazils emergy per money ratio 3.30 1012 seJ/USD L e

n.d.a. no data available.A Odum, 1996; B Odum et al., 2000; C Brown and Ulgiati, 2004; D Brandt-Williams, 20et al., 2011; I Estimated in this work. See Note#15 on Appendix B; J Assumed as chemBoustead and Hancock, 1979; O Ozkan et al., 2004; P Mu et al., 2010; Q Assuming a soAssumed as synthetic rubber fromWICEE (2003); T Cavalett and Ortega, 2010; U AssuOrtega (2009).

aTable A1Intensity factors used in this work

Item Emergy accountinga Unit Ref. Em

Sun 1.00 1000 seJ/J A eRain 3.10 1004 seJ/J B e

03 BAppendix AEmergy intensity values accounting for labor and services for human made processeb eq. equivalent oil; 1 ton-eq. 42 GJ (Jarach, 1985).

Please cite this article in press as: Agostinho, F., Ortega, E., Energetic-envJournal of Cleaner Production (2012), doi:10.1016/j.jclepro.2012.05.025ground, this cane trash is important to reduce soil loss, but har-vesting the trash to produce second generation ethanol and elec-tricity, certainty it will increase soil loss. Organic matter content

ied energyb Unit Ref. Ecological rucksack Unit Ref.

Abiotic Biotic Water

e e e e e e e

e e e e e e e

e e e e e e e

e e e e e e e

e e 0.66 0.04 0.30 kg/kg Q

kgeq/ton M 1.33 0.00 3.40 kg/kg R

kgeq/ton M 9.32 0.00 81.90 kg/kg R

kgeq/ton M 170.07 0.00 236.39 kg/kg R

kgeq/ton N 5.70 0.00 146.00 kg/kg S

kgeq/ton N 1.44 0.00 5.60 kg/kg R

kgeq/ton O 1.10 0.00 0.00 kg/kg T

kgeq/ton O 7.36 0.00 50.60 kg/kg R

kgeq/ton O 11.32 0.00 10.60 kg/kg R

kgeq/ton O 1.36 0.00 9.70 kg/kg R

kgeq/ton H 4.62 0.24 606.00 kg/kg U

kgeq/ton O 1.10 0.00 0.00 kg/kg G

kgeq/ton O 1.10 0.00 0.00 kg/kg V

kgeq/ton N n.d.a. n.d.a. n.d.a. n.d.a. n.d.a.kgeq/ton P 7.07 0.00 50.80 kg/kg Q

kgeq/ton P n.d.a. n.d.a. n.d.a. n.d.a. n.d.a.kgeq/ton P 0.25 0.00 4.10 kg/kg R

e e e e e e e

e e e e e e e

E Buranakarn, 1998; F Luchi and Ulgiati, 2000; G Cavalett and Ortega, 2009; H Browns from Odum (1996); K Felix and Tilley, 2009; L Coelho et al., 2003; M Jarach, 1985; N

ith 4% of organic matter, 30% of water and 66% of inorganic matter; R WICEE, 2003; S

as seeds from Cavalett and Ortega (2010); V Assumed as herbicide from Cavalett and

24s. Emergy baseline of 15.83 10 seJ/yr from Brown and Ulgiati (2004).


f Cle(O.M.) 4% (Odum,1996); O.M. energy 5400 kcal/kgOM. (Odum,1996); Conversion 1.4 (kgsoil/ha.yr) (0.04) (kcal/kgO M.)(4186 J kcal1) (31,000 hacane/38,750 habioref); Inputow 533 kg ha1 yr1 or 1.20 1010 J/ha/yr.

Note#6 (Concrete) e Used in industrial building, ofce, laborato-ries, repair shops and yards 4.431004 kg/yrMacedo et al. (2008);Conversion (kg/yr) * (1/38,750 ha); Input ow 1.14 kg ha1 yr1.

Note#7 (Steel) e Total steel in equipments for a plant with860,000 Lethanol/day 11,300 ton (Macedo et al., 2008); Referencefor this study 1,000,500 Lethanol/day 13,146 ton; 30 years of life-time; Conversion (ton) (1000 kg/ton) (1/30 yr lifetime) (1/38,750 ha); Input ow 11.31 kg ha1 yr1

Note#8 (Cooper) e Total cooper in equipments 66 ton (esti-mated as 0.5% of total steel); Conversion (ton) (1000 kg/ton) (1/30 yr lifetime) (1/38,750 ha); Inputow 5.67 1002 kg ha1 yr1.

Note#9 (Rubber) e Total rubber used in tires of agriculturalmachines 97,288 kg yr1 (Pereira and Ortega, 2010);Conversion (kg/yr) * (1/38,750 ha); Inputow 2.51 kg ha1 yr1.

Note#10 (Lime) e Total lime used considering a sugarcane veyears cut 10,000 kg/hacane (Macedo et al., 2008);Conversion (kg/hacane) (1/5 years) (31,000 hacane/38,750 habioref.);Input ow 1.60 1003 kg/ha/yr.

Note#11 (Nitrogen) e Total nitrogen used considering a sugar-cane ve years cut 398 kg/hacane (Macedo et al., 2008);Conversion (kg/hacane) (1/5 years) (31,000 hacane/38,750 habioref.);Input ow 63.68 kg ha1 yr1

Note#12 (Phosphorous) e Total phosphorous used consideringa sugarcane ve years cut 270 kg/hacane (Macedo et al., 2008);Conversion (kg/hacane) (1/5 years) (31,000 hacane/38,750 habioref.);Input ow 43.20 kg ha1 yr1

Note#13 (Potassium) e Total potassium used consideringa sugarcane ve years cut 690 kg/hacane (Macedo et al., 2008);Conversion (kg/hacane) (1/5 years) (31,000 hacane/38,750 habioref.);Input ow 110.4 kg ha1 yr1.

Note#14 (Diesel) e Total consumption 350 L/hacane/yr (Seabraand Macedo, 2011); Conversion (L/hacane/yr) (0.85 kg L1)(31,000 hacane/38,750 habioref.) (10,000 kcal kg1) (4186 J kcal1);Input ow 238 kg ha1 yr1 or 9.96 1009 J/ha/yr.

Note#15 (Seedlings) e Input ow 2.80 1003 kg/hacane/yr(Pereira and Ortega, 2010). For emergy intensity estimation,a parallel emergy evaluation of seedlings production was madeconsidering a greenhouse area of 1000 m2 with 70,000 plants/yrproduced. Sun (5.26 1012 J/yr), steel (5.00 1002 kg/yr), PVCplastic (4.25 1003 kg/yr), water for irrigation (2.56 1010 J/yr),electricity (3.60 1006 J/yr) and soil (organic matter;7.00 1004 kg/yr) were accounted for, resulting in an emergyintensity of 1.41 1011 seJ/kg, without accounting for labor andservices. The same procedure was made to estimate the energyintensity, reaching a value of 3.78 1002 kgeq.oil/kg.

Note#16 (Herbicide) e Total herbicide used consideringa sugarcane ve years cut 11 kg/hacane (Macedo et al., 2008).Conversion (kg/hacane) (1/5 years) (31,000 hacane/38,750 habioref.);Input ow 1.76 kg ha1 yr1

Note#17 (Insecticide) e Total insecticide used consideringa sugarcane ve years cut 0.80 kg/hacane (Macedo et al., 2008).Conversion (kg/hacane) (1/5 years) (31,000 hacane/38,750 habioref.);Input ow 1.28 1001 kg ha1 yr1.

Note#18 (Enzyme for adjacent plant) e Assuming that sugar-cane bagasse has the same characteristics of corn stover, theenzyme consumption in a biochemical conversion is 613 kgenzyme/hfor a 98,039 kgwet-biomass/h (Mu et al., 2010). Reference for thisstudy for bagasse used in second generation ethanol

F. Agostinho, E. Ortega / Journal o14production 266,533 tondry-bagasse/yr; Conversion (kgenzyme/h)

Please cite this article in press as: Agostinho, F., Ortega, E., Energetic-envJournal of Cleaner Production (2012), doi:10.1016/j.jclepro.2012.05.025(h/kgwet-bagasse) (tondry-bagasse/yr) (1000 kgdry-bagasse/tondry-bagasse)(2 kgwet-bagasse/kgdry-bagasse) (1/38,750 habioref.); Inputow 86 kgenzyme/ha/yr.

Note#19 (Lime for adjacent plant) e Assuming that sugarcanebagasse has the same characteristics of corn stover, the limeconsumption in a biochemical conversion is 2395 kglime/h fora 98,039 kgwet-biomass/h (Mu et al., 2010). Reference for this studyfor bagasse used in second generation ethanolproduction 266,533 tondry-bagasse/yr; Conversion (kglime/h) (h/kgwet-bagasse) (tondry-bagasse/yr) (1000 kgdry-bagasse/tondry-bagasse)(2 kgwet-bagasse/kgdry-bagasse) (1/38,750 habioref.); Inputow 336.06 kglime/ha/yr.

Note#20 (Water for adjacent plant) e Assuming that sugarcanebagasse has the same characteristics of corn stover, the waterconsumption in a biochemical conversion is 186,649 kgwater/h fora 98,039 kgwet-biomass/h (Mu et al., 2010). Reference for this studyfor bagasse used in second generation ethanolproduction 266,533 tondry-bagasse/yr; Conversion (kgwater/h) (h/kgwet-bagasse) (tondry-bagasse/yr) (1000 kgdry-bagasse/tondry-bagasse)(2 kgwet-bagasse/kgdry-bagasse) (1/38,750 habioref.); Inputow 2.62 1004 kgwater/ha/yr.

Note#21 (Sulfuric acid for adjacent plant) e Assuming thatsugarcane bagasse has the same characteristics of corn stover, thesulfuric acid consumption in a biochemical conversion is3288 kgacid/h for a 98,039 kgwet-biomass/h (Mu et al., 2010). Refer-ence for this study for bagasse used in second generation ethanolproduction 266,533 tondry-bagasse/yr; Conversion (kgacid/h) (h/kgwet-bagasse) (tondry-bagasse/yr) (1000 kgdry-bagasse/tondry-bagasse)(2 kgwet-bagasse/kgdry-bagasse) (1/38,750 habioref.); Inputow 461.36 kgacid/ha/yr.

Note#22 (Diammonium phosphate for adjacent plant) eAssuming that sugarcane bagasse has the same characteristics ofcorn stover, the diammonium phosphate consumption ina biochemical conversion is 154 kgphosphate/h for a 98,039 kgwet-biomass/h (Mu et al., 2010). Reference for this study for bagasse usedin second generation ethanol production 266,533 tondry-bagasse/yr; Conversion (kgphosphate/h) (h/kgwet-bagasse) (tondry-bagasse/yr)(1000 kgdry-bagasse/tondry-bagasse) (2 kgwet-bagasse/kgdry-bagasse) (1/38,750 habioref.); Input ow 21.61 kgphosphate/ha/yr.

Note#23 (Corn steep liquor for adjacent plant; organic nitrogensource) e In Brazil, this source of organic nitrogen could beobtained from other source, but we decided to keep with thissource to maintain the same nitrogen balance of Mu et al. (2010).Assuming that sugarcane bagasse has the same characteristics ofcorn stover, the corn steep liquor consumption in a biochemicalconversion is 1232 kgliquor/h for a 98,039 kgwet-biomass/h (Mu et al.,2010). Reference for this study for bagasse used in second genera-tion ethanol production 266,533 tondry-bagasse/yr;Conversion (kgliquor/h) (h/kgwet-bagasse) (tondry-bagasse/yr)(1000 kgdry-bagasse/tondry-bagasse) (2 kgwet-bagasse/kgdry-bagasse) (1/38,750 habioref.); Input ow 172.87 kgliquor/ha/yr.

Note#24 (Labor) e Labor hours for conventional sugarcaneethanol production in Brazil (Pereira, 2008): Agriculturalphase 0.01183 h/Lethanol of temporary work 0.00507 h/Lethanolof permanent work; Sugarcane transport 0.0005 h/Lethanol;Industrial phase 0.0012 h/Lethanol. For biorenery scenario,sugarcane will be totally harvested by machines, thus the tempo-rary work during agricultural phase will not be necessary. Never-theless, an increase of permanent workers during agricultural,transport and industrial phases will be necessary due to increase ofharvesters, transport and mills productivity. For bioreneryscenario, we assumed an increase in 10% on Pereiras (2008) values,except for temporary work on agricultural phase that was dis-regarded. Reference for this study 2,945,000 ton /yr and

aner Production xxx (2012) 1e16cane-wet124 Lethanol/toncane-wet; Conversion [(1.1) (h/Lethanol for


American Scientist 97, 230e237.Hall, J., Matos, S., Severino, L., Beltro, N., 2009. Brazilian biofuels and social

f Clepermanent work in agricultural phase) (1.1) (h/Lethanol fortransport phase) (1.1) (h/Lethanol for industrial phase)] (toncane-wet/yr) (Lethanol/toncane-wet) (1/38,750 ha); Inputow 70.18 h ha1 yr1

Note#25 (Services) e Services for current ethanol plant 365USD/ha/yr (Pereira and Ortega, 2010). It was assumed an increase in10% of services value for Biorenery scenario; Services includetaxes and private services; Negative externalities 230 USD/ha/yr(Pretty et al., 2005); Conversion [(1.1) (365 USD/ha bioref./yr)] [(230 USD/hacane/yr) (31,000 hacane/38,750 habioref.)]; Inputow 585.5 USD/ha/yr.

Note#26 (Ethanol) e Ethanol produced by conventionalmill 91 L/toncane-wet; Ethanol produced by adjacentplant 33.48 L/toncane-wet (Seabra and Macedo, 2011); Referencefor this study 2,945,000 toncane-wet/yr; Conversion [(91 L/ton-cane-wet) (33.48 L/toncane-wet)] (2,945,000 toncane-wet/yr) (1/38,750 habioref.); Output ow 9461 L ha1 yr1.

Note#27 (Electricity) e Electricity demanded for bioreneryinternal processes 28 kWh/toncane-wet; Electricity produced byconventional mill 32 kWh/toncane-w

energetic-environmental assessment of a scenario for brazilian cellulosic ethanol

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