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Assessing the sustainability of bioethanol production in different development contexts: A systems approach
KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The continuous depletion of fossil fuel reserves, the global agenda on climate change and threats to energy security have led to increased global interest in the exploration, production and utilisation of bioenergy and biofuels. Access to modern bioenergy carriers derived from the efficient conversion of locally available biomass resources is indispensable for economic growth, rural development and sustainable development in developing countries. Deployment of bioenergy/biofuels technologies has significantly varied across the globe. The least developed countries (LDCs) and developing countries are still highly dependent on traditional biomass technologies with low conversion efficiency, which are typically associated with significant environmental and health impacts. Meanwhile, emerging economies and developed countries are progressively promoting biofuel industries and international trade. They are also engaged in making biofuels a sustainable proposition by developing sustainability criteria. The goal of this thesis is to address the sustainability of bioethanol production derived from one of the key feedstocks/energy crops: sugarcane. This will be done by analysing different development contexts and environmental constraints in terms of geopolitical situation, economic development and state-of-the-art technologies in agro-industrial development. Life cycle assessment (LCA), system studies, and techno-economic optimisation are the main methodological approaches applied in the thesis. The thesis primarily addresses three key questions for analysing the sustainability of bioethanol production.

The first research question investigates the key parameters affecting the sustainability of bioethanol production and use in a low-income country using the case of Nepal. The net energy and greenhouse gas (GHG) balances are identified to be the main sustainability criteria of the sugarcane-molasses bioethanol (Paper I and II). Results of the lifecycle studies show that the production of bioethanol is energy-efficient in terms of the fossil fuel inputs required to produce the renewable fuel. Greenhouse gas (GHG) emissions from the production and combustion of ethanol are also lower than those from gasoline. The study also evaluates the socio-economic and environmental benefits of ethanol production and use in Nepal, concluding that the major sustainability indicators are in line with the goals of sustainable development (Paper III). Assessment of the biofuel (molasses-bioethanol) sustainability in Nepal is the first of its kind in low-income countries, and serves also the purpose of motivating the assessment of ethanol production potential in other LDCs, particularly in sub-Saharan Africa.

The second question critically evaluates methodologies for accounting the lifecycle GHG emissions of Brazilian sugarcane ethanol in European and American regulations, depicting commonalities and differences among them (Paper IV). GHG emissions are becoming increasingly important as part of sustainability criteria in the context of the expansion of biofuel production and international trade. However, different methodologies still lead to quite different results and interpretation. To make this an operational criterion for international comparisons, it is necessary to establish unified methodological procedures for accounting GHG emissions. The thesis identifies the major issues as  N2O emissions from agricultural practices, bioelectricity credits in fuel production, and modelling approaches in estimating emissions related to direct and indirect land use change (LUC & iLUC), that need to be addressed for establishing methodological coherences.

The third research question investigates how the sugarcane bioethanol industry can be developed in terms of energy security and the diversification of energy sources. The case of complementarity between bioelectricity and hydropower is evaluated in the cases of Nepal and Brazil and presented in Paper V. Bioelectricity could offer a significant share of electricity supply in both countries provided that favourable political and institutional conditions are applied. Finally, in order to find the choice of technological options for the production of second generation (2G) bioethanol and/or of bioelectricity, a techno-economic optimisation study on the bulk of sugarcane bio-refineries in Brazil is carried out in Paper VI, taking into account the entire lifecycle costs, emissions, and international trade. The study shows that it is worthwhile to upgrade sugarcane bio-refineries. Energy prices, type of power generation systems, biofuel support and carbon tax, and conversion efficiencies are the major factors influencing the technological choice and potential bioethanol trade.

In short, this dissertation provides insights on the sustainability of the bioethanol production/industry and its potential role in the mitigation of climate change, improved energy security and sustainable development in different country contexts, as well as methodological contributions for assessing the sustainability of biofuels production in connection with energy and climate policies.

Abstract [sv]

Intresset för ökad exploatering, produktion och användning av bioenergi och biobränslen har föranletts av den kontinuerliga utmattningen av fossila bränslen, den globala agendan för att motverka klimatförändringar samt hoten mot energisäkerheten. Tillgången till moderna bioenergibärare, effektivt framställda från lokal råvara, är grundläggande för ekonomisk tillväxt, landsbygdsutveckling samt för hållbar utveckling i utvecklingsländer. Användandet av bioenergi- och biobränsleteknologi har varierat markant världen över. De minst utvecklade länderna (LDCs) samt övriga utvecklingsländer är fortfarande beroende av traditionella biomassabaserade tekniker till stor utsträckning. Dessa tekniker har låg effektivitet och är ofta sammankopplade med stora miljö- och hälsoskador. Samtidigt främjar tillväxtekonomier och utvecklingsländer biobränsleindustrin och internationell handel progressivt. Länderna arbetar även för att biobränslen ska bli ett hållbart alternativ genom att utveckla hållbarhetskriterier. Den här avhandlingens mål är att adressera hållbarheten hos bioetanolproduktion från sockerrör, en av bioetanolens nyckelråvaror. Målet kommer att nås genom analyser av industrins nationella utvecklingsmiljö samt miljö- och klimatmässiga begränsningar som härstammar från den geopolitiska situationen och den ekonomiska tillväxten i landet, samt analyser av teknologier i den agro-industriella utvecklingen. De huvudsakliga metoder som använts är livscykelanalys (LCA), systemstudier och tekno-ekonomisk optimering. Avhandlingen adresserar primärt tre nyckelfrågor för att analysera hållbarheten hos bioetanolproduktion.

Den första forskningsfrågan belyser hur nyckelparametrar påverkar hållbarheten hos produktion och användning av bioetanol i låginkomstländer, med fallstudien Nepal som utgångspunkt. Nettoenergi- och växthusgasbalanser identifieras som de huvudsakliga hållbarhetskriterierna för sockerrör-melass-baserad bioetanol (Artikel I och II). Livscykelstudiernas resultat visar att produktionen av bioetanol är energieffektiv sett från den mängd fossila bränslen som produktionen av förnybart bränsle krävt. Växthusgasutsläppen från produktion och förbränning av etanol är dessutom lägre än utsläppen från bensin. Studien utvärderar de socio-ekonomiska och miljö- och klimatmässiga fördelarna med produktion och användning av etanol i Nepal. Slutsatsen är att indikatorerna för hållbarhet ligger i linje med målen för hållbar utveckling (Artikel III). Bedömningen av biobränslens (melass-baserad etanol) hållbarhet i Nepal är den första studien i sitt slag för låginkomstländer. Studien motiverar dessutom en bedömning av potentialen för etanolproduktion i andra LDCs, speciellt i de afrikanska länderna söder om Sahara.

Den andra forskningsfrågan kräver en kritisk utvärdering av metoderna för hur livscykelutsläpp från brasiliansk sockerrörsetanol redovisas i europeiska och amerikanska regleringar (Artikel IV). Artikeln, som påvisar likheter och skillnader mellan regionerna, visar att växthusgasutsläpp blir en mer och mer viktig del i hur hållbarhetskriterier definieras när expansionen av biobränsleproduktion och internationell handel diskuteras. Olika metoder för redovisningen av växthusgasutsläpp leder dock till mycket olika resultat och tolkningar. Det är nödvändigt att etablera en enhetlig metod för redovisning av växthusgasutsläpp för att skapa ett kriterium som möjliggör internationella jämförelser. Avhandlingen identifierar de mest beaktansvärda problemen för att etablera en enhetlig metod: N2O-utsläpp från jordbruksprocesser, tillgodoräknande av bioelektricitet inom bränsleproduktion, samt modelleringsmetoder för att uppskatta utsläpp relaterade till direkt och indirekt landanvändning (LUC och iLUC).

Den tredje forskningsfrågan utreder hur industrin för sockerrörsbioetanol kan utvecklas från ett energisäkerhetsperspektiv, med speciell hänsyn till diversifieringen av energikällor. I Artikel V presenteras hur bioelektricitetsproduktion och vattenkraft kan komplettera varandra i fallen Nepal och Brasilien. Bioelektricitet skulle kunna bidra markant till tillförseln av elektricitet i båda länderna under förutsättning att de politiska och institutionella förutsättningarna är fördelaktiga. Slutligen utförs en tekno-ekonomisk studie för att identifiera den optimala teknologin för produktion av andra generationens (2G) bioetanol och/eller bioelektricitet. Studien görs för merparten av sockerrörsbioraffinaderierna i Brasilien och utgör Artikel VI. Studien tar fullskaliga livscykelkostnader i beaktande samt utsläpp och internationell handel. Studien visar att det är värt mödan att uppgradera befintliga sockerrörsbioraffinaderier. De dominerande påverkansfaktorerna för valet av teknologi och potentialen för bioetanolhandel är energipriser, typ av kraftproduktionssystem, biobränslestöd och koldioxidskatt, samt processernas effektivitet.

Kortfattat behandlar den här avhandlingen bioetanolproduktionens och bioetanolindustrins hållbarhet. Avhandlingen ger insikt i dess potentiella roll för att motverka klimatförändringar, förbättra energisäkerhet samt främja hållbar utveckling i olika nationella sammanhang. Avhandlingen bidrar dessutom med metodutveckling i hur hållbarheten av biobränsleproduktion bedöms inom ramen för energi- och klimatpolicy.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2013. , xx, 124 p.
Series
TRITA-ECS, 2013:01
Keyword [en]
bioenergy and biofuel, bioethanol industry, development trend, sustainability assessment, climate change mitigation, energy security, life cycle assessment, systems optimisation
Keyword [sv]
bioenergi och biobränsle, bioetanolindustri, utvecklingstrender, hållbarhetsbedömning, motverka klimatförändringar, energisäkerhet, livscykelanalys, systemoptimering
National Category
Energy Engineering
Research subject
SRA - Energy
Identifiers
URN: urn:nbn:se:kth:diva-125618ISBN: 978-91-7501-823-2 (print)OAI: oai:DiVA.org:kth-125618DiVA: diva2:640326
Public defence
2013-09-12, F3, Lindstedtsvägen 26, Stockholm, 13:00 (English)
Opponent
Supervisors
Note

QC 20130813

Available from: 2013-08-13 Created: 2013-08-13 Last updated: 2013-08-13Bibliographically approved
List of papers
1. Net energy balance of molasses based ethanol: The case of Nepal
Open this publication in new window or tab >>Net energy balance of molasses based ethanol: The case of Nepal
2009 (English)In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 13, no 9, 2515-2524 p.Article in journal (Refereed) Published
Abstract [en]

This paper evaluates life cycle energy analysis of molasses based ethanol (MOE) in Nepal. Net energy value (NEV), net renewable energy value (NREV) and energy yield ratio are used to evaluate the energy balance of MOE in Nepal. Total energy requirements in sugarcane farming, cane milling and ethanol conversion processes are estimated and energy allocation is made between co-products (molasses and sugar) as per their market prices. The result shows negative NEV (−13.05 MJ/L), positive NREV (18.36 MJ/L) and energy yield ratio (7.47). The higher positive value of NREV and energy yield ratio reveal that a low amount of fossil fuels are required to produce 1 L of MOE. However, negative NEV reveals that the total energy consumption (both fossil and renewables) to produce the ethanol is higher than its final energy content. Nevertheless, the renewable energy contribution amounts to 91.7% of total energy requirements. The effect of the increased price of molasses and reduced energy consumption in the sugarcane milling and ethanol conversion are found to be significant in determining the energy values and yield ratio of MOE. In addition, there are clear measures that can be taken to improve efficiency along the production chain. Finally, energy security, scarcity of hard currency for importing fossil fuels and opportunities for regional development are also strong reasons for considering local renewable energy options in developing countries.

Place, publisher, year, edition, pages
Elsevier's ScienceDirect, 2009
Keyword
Molasses-based ethanol; Life cycle energy analysis; Net energy value; Energy yield ratio; Nepal
Identifiers
urn:nbn:se:kth:diva-25315 (URN)10.1016/j.rser.2009.06.028 (DOI)000270637000025 ()2-s2.0-68749100592 (Scopus ID)
Note
QC 20101029Available from: 2010-10-18 Created: 2010-10-18 Last updated: 2017-12-12Bibliographically approved
2. Greenhouse gas balances of molasses based ethanol in Nepal
Open this publication in new window or tab >>Greenhouse gas balances of molasses based ethanol in Nepal
2011 (English)In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 19, no 13, 1471-1485 p.Article in journal (Refereed) Published
Abstract [en]

This paper evaluates life cycle greenhouse gas (GHG) balances in production and use of molasses-based ethanol (EtOH) in Nepal. The total life cycle emissions of EtOH is estimated at 432.5 kgCO(2eq) m(-3) ethanol (i.e. 20.4 gCO(2eq) MJ(-1)). Avoided emissions are 76.6% when conventional gasoline is replaced by molasses derived ethanol. A sensitivity analysis was performed to verify the impact of variations in material and energy flows, and allocation ratios in the GHG balances. Market prices of sugar and molasses, amount of nitrogen-fertilizers used in sugarcane production, and sugarcane yield per hectare turn out to be important parameters for the GHG balances estimation. Sales of the surplus electricity derived from bagasse could reduce emissions by replacing electricity produced in diesel power plants. Scenario analysis on two wastewater processes for treatment of effluents obtained from ethanol conversion has also been carried out. If wastewater generated from ethanol conversion unit is treated in pond stabilization (PS) treatment process, GHG emissions alarmingly increase to a level of 4032 kgCO(2eq) m(-3) ethanol. Results also show that the anaerobic digestion process (ADP) and biogas recovery without leakages can significantly avoid GHG emissions, and improve the overall emissions balance of EtOH in Nepal. At a 10% biogas leakage, life cycle emissions is 1038 kgCO(2eq) m(-3) ethanol which corresponds to 44% avoided emissions compared to gasoline. On the other hand, total emissions surpass the level of its counterpart (i.e. gasoline) when the leakage of biogas exceeds 23.4%.

Keyword
Greenhouse gas balances, Life cycle analysis, Molasses based ethanol, Nepal
National Category
Other Environmental Engineering
Identifiers
urn:nbn:se:kth:diva-25317 (URN)10.1016/j.jclepro.2011.04.012 (DOI)000293118400009 ()2-s2.0-79959763813 (Scopus ID)
Note
QC 20101029. Updated from submitted to published.Available from: 2010-10-18 Created: 2010-10-18 Last updated: 2017-12-12Bibliographically approved
3. Ethanol production and fuel substitution in Nepal—Opportunity to promote sustainable development and climate change mitigation
Open this publication in new window or tab >>Ethanol production and fuel substitution in Nepal—Opportunity to promote sustainable development and climate change mitigation
2010 (English)In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 14, no 6, 1644-1652 p.Article in journal (Refereed) Published
Abstract [en]

This paper explores the potential for ethanol production and fuel substitution in Nepal based on established sugarcane production, installed capacity for sugar and ethanol production, economic opportunities for the national economy, and potential to reduce greenhouse gas emissions. At present conditions, 18,045 m3 ethanol can be annually produced in Nepal without compromising the production of food products from sugar cane such as sugar, chaku and shakhar. The effects for the country can be manifold. As much as 14% of gasoline import reduction, and annual savings of US$ 10 million could be achieved through the introduction of the E20. The activity can provide an incentive for improved yields in sugarcane production, and help develop the industrial sector. This, in turn, will have a positive effect in terms of job and income generation in the rural areas where 85% of the population live. Improvement of agricultural practices for sugarcane could also have an indirect and positive effect on improving other agriculture activities. Furthermore, the use of ethanol in the transport sector will have a positive environmental effect while reducing CO2 emissions and combating pollution in the Kathmandu Valley. Finally, the substitution of ethanol in transport will imply lower imports of oil products and less draining of resources from the Nepalese economy.

Place, publisher, year, edition, pages
Elsevier's ScienceDirect, 2010
Keyword
Ethanol; Bioenergy; Developing countries; Fuel substitution; Sustainable development
Identifiers
urn:nbn:se:kth:diva-25319 (URN)10.1016/j.rser.2010.03.004 (DOI)000278300500015 ()2-s2.0-77950857987 (Scopus ID)
Note
QC 20101029Available from: 2010-10-18 Created: 2010-10-18 Last updated: 2017-12-12Bibliographically approved
4. Accounting greenhouse gas emissions in the lifecycle of Brazilian sugarcane bioethanol: Methodological references in European and American regulations
Open this publication in new window or tab >>Accounting greenhouse gas emissions in the lifecycle of Brazilian sugarcane bioethanol: Methodological references in European and American regulations
2012 (English)In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 47, 384-397 p.Article in journal (Refereed) Published
Abstract [en]

This study discusses four European and American regulatory schemes designed for accounting lifecycle GHG emissions in relation to the Brazilian sugarcane ethanol. The objective is to critically examine the methodologies and associated parameters used in existing regulatory schemes for calculating GHG emissions, and to explore methodological convergences. The issues related to direct lifecycle and indirect land use change emissions have been addressed. It is found that there are commonalities between the European Renewable Energy Directive (EU-RED) and the UK's Renewable Transport Fuels Obligation (UK-RTFO), but the US-EPA's Renewable Fuel Standard (US-EPA) and the Low Carbon Fuel Standard of the California Air Resources Board (CA-CARB) vary greatly not only among themselves, but also in relation to the European regulations. Agricultural practices (especially soil carbon and nitrogen dynamics), co-product credits from surplus electricity and uncertainties around economic modeling approaches for indirect land use change are the major areas where methodological divergences exist. Incorporation of domestic agricultural practices, sugarcane mills operations, and realistic modeling of indirect impacts of land use change using regional models could provide more coherence in estimations of GHG emissions. Furthermore, the Brazilian trend of novelty in all phases of sugarcane bioenergy systems should be considered when projecting GHG emissions.

Keyword
Biofuels, Sustainability assessment, Regulatory schemes
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-80208 (URN)10.1016/j.enpol.2012.05.005 (DOI)000306200100038 ()2-s2.0-84862258179 (Scopus ID)
Funder
Swedish Energy Agency
Note

QC 20150625

Available from: 2012-02-09 Created: 2012-02-09 Last updated: 2017-12-07Bibliographically approved
5. Power generation from sugarcane biomass - A complementary option to hydroelectricity in Nepal and Brazil
Open this publication in new window or tab >>Power generation from sugarcane biomass - A complementary option to hydroelectricity in Nepal and Brazil
2012 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 48, no 1, 241-254 p.Article in journal (Refereed) Published
Abstract [en]

This paper discusses the complementarity between hydroelectricity and surplus electricity from sugarcane biomass based cogeneration plants in sugarcane mills. The paper investigates opportunities and barriers in the context of governments' initiatives, institutions and prevailing regulatory frameworks in Brazil and Nepal. The paper finds that bioelectricity from cogeneration can be a good complementary option for hydroelectric power, helping foster diversification on the generation side and enhance security of electricity supply based on local resources. Bioelectricity potential from sugarcane biomass is estimated to be in the range of 209 - 313 GWh for Nepal and 62 -93 TWh for Brazil. In Nepal, the grid connected bioelectricity can provide power for operating industries, and support local development through rural electrification. In Brazil, the biomass potential can be further enhanced through a better utilization of the biomass in the sugar-ethanol industry to balance hydropower availability. This comparative study offers a reflection on the need for better planning and policies to address the barriers which are hindering the development of bioelectricity even in places where the potential is large.

Keyword
Sugarcane biomass, Bioelectricity, Hydroelectricity, Complementarity
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-80105 (URN)10.1016/j.energy.2012.03.015 (DOI)000313461800029 ()2-s2.0-84869868087 (Scopus ID)
Note

QC 20120111. Updated from accepted to published.

Available from: 2012-02-09 Created: 2012-02-09 Last updated: 2017-12-07Bibliographically approved
6. Optimizing ethanol and bioelectricity production in sugarcane biorefineries in Brazil
Open this publication in new window or tab >>Optimizing ethanol and bioelectricity production in sugarcane biorefineries in Brazil
2016 (English)In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 85, 371-386 p.Article in journal (Refereed) Published
Abstract [en]

In sugarcane biorefineries, the lignocellulosic portion of the sugarcane biomass (i.e. bagasse and cane trash) can be used as fuel for electricity production and/or feedstock for second generation (2G) ethanol. This study presents a techno-economic analysis of upgraded sugarcane biorefineries in Brazil, aiming at utilizing surplus bagasse and cane trash for electricity and/or ethanol production. The study investigates the trade-off on sugarcane biomass use for energy production: bioelectricity versus 2G ethanol production. The BeWhere mixed integer and spatially explicit model is used for evaluating the choice of technological options. Different scenarios are developed to find the optimal utilization of sugarcane biomass. The study finds that energy prices, type of electricity substituted, biofuel support and carbon tax, investment costs, and conversion efficiencies are the major factors influencing the technological choice. At the existing market and technological conditions applied in the upgraded biorefineries, 300 PJ y-1 2G ethanol could be optimally produced and exported to the EU, which corresponds to 2.5% of total transport fuel demand in the EU. This study provides a methodological framework on how to optimize the alternative use of agricultural residues and industrial co-products for energy production in agro-industries considering biomass supply chains, the pattern of domestic energy demand, and biofuel trade.

Place, publisher, year, edition, pages
Elsevier, 2016
Keyword
Second generation bioethanol, Bioelectricity, Systems optimization
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-125616 (URN)10.1016/j.renene.2015.06.009 (DOI)000363344800036 ()2-s2.0-84935471391 (Scopus ID)
Funder
Swedish Research Council Formas
Note

QC 20151118

Available from: 2013-08-13 Created: 2013-08-13 Last updated: 2017-12-06Bibliographically approved

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