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CONTACT INFORMATION
Assessing the sustainability of bioethanol production: Key criteria and methodological improvements
PhD Student Dilip KhatiwadaSupervisor Semida Silveira
Dilip Khatiwada
PhD Student
Address:
KTH – Energy and Climate Studies
Brinellvägen 68
SE-100 44 STOCKHOLM
Telephone:
+46(0)8-790-7431
+46 (0)70-772-9140 (mobile)
E-mail:
Web: www.ecs.kth.se
The division of Energy and Climate Studies (ECS) has an interdisciplinary character with a strong systems approach, linking issues related to energy technology and policy, climate change and sustainable development.
At present, ECS works with three defined research themes:
• bioenergy systems,
• rural electrification, and
• energy and climate policy.
These are some of the central research questions at ECS.
What solutions can be pursued globally and regionally?
Which of them will lead to sustainable development?
What are the solutions that will lead to mitigation and adaptation to climate change while also promoting sustainable development?
www.ecs.kth.se
Life cycle and sustainability assessment of bioenergy systems:
Energy and Climate Studies
Dept. of Energy Technology
School of Industrial Engineering and Management (ITM)
Brief Introduction
Life cycle assessment (LCA) and sustainabilitycriteria provide the methodological framework forthe sustainability of the bioethanol production. Thisresearch project deals with the net energy balance,greenhouse gas (GHG) emissions, and prospectsfor sustainable development of sugarcanebioenergy systems in developing countries,including least developed countries (LDCs).
Key Research Questions ?
How much total energy does it take to produce one liter of bioethanol?
How much GHG emissions savings occur? What are the direct benefits of bioethanol in
developing countries? What are the sustainability criteria and how to
assess them? How can we compare and benchmark the
sustainability criteria globally?
The case of Nepal, a LDC in Asia
Map of Nepal with sugarmills’ location
LCA – Concept and Framework
Results
Energy yield ratio in the production of molasses-based ethanol is 7.47
Life cycle greenhouse gas (GHG) emissions from production and use are 76.6 % lower than those of conventional gasoline.
National bioethanol potential:18 million liters/year, thus improved energy security situation through replacement of gasoline
Bioethanol blends reduce local air pollution problems in the Kathmandu Valley
Saving of hard-cash foreign currency; substitution of gasoline with E20 saves US$ 10.1 million a year in the Kathmandu Valley
E20 can avoid 23,397 tonnes of CO2 emissions Wastewater treatment: Anaerobic Digestion
Process with biogas recovery is the best option to reduce the life cycle GHG emissions
No conflicts between food and fuel at present small-scale production from low-value sugarcane by-product, Molasses
Energy and material flows for sugarcane bioenergy systems in Nepal (per hectare)
GHG emissions in varying material/energy inputs and sugarcane yield
Fuel consumption along the production chain
Sources of life cycle GHG emissions in bioethanol production and use (per m3 ethanol) in Nepal
Utilization of the available primary energy (bagasse: 96% and biogas: 4%).
References:
1. Khatiwada, D., Silveira, S., Net energy balance of molasses based ethanol: the case of Nepal.Renewable and Sustainable Energy Reviews 13 (2009), pp.2515 – 2524.
2. Silveira, S., Khatiwada, D., Ethanol Production and Fuel Substitution in Nepal Opportunity toPromote Sustainable Development and Climate Change Mitigation. Renewable and SustainableEnergy Reviews 14 (2010), pp 1644-1652.
3. Khatiwada, D., Silveira, S., Greenhouse gas balances of molasses based ethanol in Nepal(under review), submitted in Journal of Cleaner Production (2010).
Future Direction: Methodological Improvements
To improve and benchmark the sustainability assessment criteria of the bioethanol production for methodological coherence and unification in the context of the evaluation of sustainable bioenergy systems for energy security, climate change, product certification, and international trade
Fermentation/distillation, 4%
ETP
Lighting to industrial complex (milling, distillation and ETP), 4%
Sugarcane milling, 73%
Excess bagasse, 17%
Dehydration, 2%
Fossil fuels :
51.9% (224.4 kg)
Trash burning
5.3% (22.9 kg)
Soil emissions
26.8% (116.1 kg)
Bagasse and
biogas combustion
10.2% (44.1 kg)
Emissions from
combustion of ethanol
5.8% (25 kg)
Fertilizers/chemicals production Diesel consumption (in trans./irrigation) Human labour activities
Fertilizer’s application Returned residues (spent wash, filter cake, and unburned cane-trash/residues)
Sri Ram Sugar Mills Pvt. Ltd. (SRSM)
SRSM
Cane farming
Transportation
Transportation
Excess bagasse
Cane milling
Molasses
Sugar
Ethanol conversion
Ethanol
Wastewater treatment Plant
(Recovery of biogas)
Areas of Improvements for Energy and GHG Balances
Improvement in cane yields with the help of the modernization of agricultural practices
Efficient use of cane bagasse and trash/wastes Technological upgrading and optimization of
industrial operations
Key messages:
Significant reduction in GHG emissions with the increase in cane yield/productivity.
Use of N-fertilizer has a higher impact