Greenhouse gas emissions and energy balances of jatropha biodiesel as an alternative fuel in Tanzania |
| |
| Affiliation: | 1. University of Dar es Salaam, College of Engineering and Technology, Department of Chemical and Mining Engineering, P.O. Box 35131, Dar es Salaam, Tanzania;2. International Development Research Centre, P. O Box 62084 00-200, Nairobi, Kenya;1. Grup ASPA, Departament de Tecnologia de''Aliments, Universitat Politècnica de València, Camí de Vera s/n, 46022, València, Spain;2. Departamento de Análisis Económico Aplicado, Universidad de Las Palmas de Gran Canaria, Saulo Torón 4, 35300, Las Palmas de GC, Spain;3. School of Environmental Engineering, Technical University of Crete, 73100 Chania, Greece;1. Department of Automobile Engineering, Rajalakshmi Engineering College, Chennai 602105, India;2. Department of Mechanical Engineering, Dr. M.G.R Educational and Research Institute, Chennai 600095, India;3. Department of Mechanical Engineering, Anna University, Chennai 600025, India;1. Environmental Engineering Program (PEA), Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil;2. Program in Chemical and Biochemical Process Technology (TPQB), Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil;3. National Center for Beef Cattle Research (CNPGC), Brazilian Agricultural Research Corporation (Embrapa), Campo Grande, MS, Brazil |
| |
| Abstract: | This paper evaluates GHG emissions and energy balances (i.e. net energy value (NEV), net renewable energy value (NREV) and net energy ratio (NER)) of jatropha biodiesel as an alternative fuel in Tanzania by using life cycle assessment (LCA) approach. The functional unit (FU) was defined as 1 tonne (t) of combusted jatropha biodiesel. The findings of the study prove wrong the notion that biofuels are carbon neutral, thus can mitigate climate change. A net GHG equivalent emission of about 848 kg t−1 was observed. The processes which account significantly to GHG emissions are the end use of biodiesel (about 82%) followed by farming of jatropha for about 13%. Sensitivity analysis indicates that replacing diesel with biodiesel in irrigation of jatropha farms decreases the net GHG emissions by 7.7% while avoiding irrigation may reduce net GHG emissions by 12%. About 22.0 GJ of energy is consumed to produce 1 t of biodiesel. Biodiesel conversion found to be a major energy consuming process (about 64.7%) followed by jatropha farming for about 30.4% of total energy. The NEV is 19.2 GJ t−1, indicating significant energy gain of jatropha biodiesel. The NREV is 23.1 GJ t−1 while NER is 2.3; the two values indicate that large amount of fossil energy is used to produce biodiesel. The results of the study are meant to inform stakeholders and policy makers in the bioenergy sector. |
| |
| Keywords: | Jatropha biodiesel Greenhouse gas emissions Energy balances Life cycle assessment Tanzania |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
