Long-Term Bioethanol System and Its Implications on GHG Emissions: A Case Study of Thailand
Thapat Silalertruksa, Shabbir H. Gheewala
Environmental Science & Technology · 2011
The study evaluates greenhouse gas (GHG) emissions performance of future bioethanol systems in Thailand to ascertain whether bioethanol for transport could help the country mitigate a global warming impact. GHG emission factors of bioethanol derived from cassava, molasses, and sugar cane are analyzed using 12 scenarios covering the critical variables possibly affecting the GHG performance, i.e., (1) the possible direct land use change caused by expanding feedstock cultivation areas; (2) types of energy carriers used in ethanol plants; and (3) waste utilization, e.g., biogas recovery and dry distillers grains with solubles (DDGS) production. The assessment reveals that GHG performance of a Thai bioethanol system is inclined to decrease in the long run due to the effects from the expansion of plantation areas to satisfy the deficit of cassava and molasses. Therefore, bioethanol will contribute to the country's strategic plan on GHG mitigation in the transportation sector only if the production systems are sustainably managed, i.e., coal replaced by biomass in ethanol plants, biogas recovery, and adoption of improved agricultural practices to increase crop productivity without intensification of chemical fertilizers. Achieving the year 2022 government policy targets for bioethanol with recommended measures would help mitigate GHG emissions up to 4.6 Gg CO(2)-eq per year.
The environmental and socio-economic impacts of bio-ethanol production in Thailand
Thapat Silalertruksa, Shabbir H. Gheewala
Energy Procedia · 2011
The study assesses the impacts of the bio-ethanol production to the environment and socio-economic development in Thailand. The key assessment elements include greenhouse gas (GHG) emissions performance, employment generation, and economic effects on gross domestic product (GDP) and trade balance of Thai economy. The results reveal that there are wide ranges of GHG emissions depending upon the production environment and especially when direct land-use change is included in the system boundary. GHG emissions for cassava and molasses ethanol range between 27 – 91 and 28 – 100 g CO2-eq per MJ ethanol, respectively. For socio-economic impacts, producing bio-ethanol requires about 17-20 times more workers than gasoline for the same amount of final energy. Direct employment in agriculture contributes to more than 90% of the total employment. In addition, production of 1 TJ bio-ethanol could result in an additional GDP around 0.7-0.9 M.THB and the increase of imported goods worth 0.7-1.8 M.THB. However, around 0.4-1.1 M.THB of imports would be saved per TJ from the promoting use of bio-ethanol to substitute gasoline. These obtained externalities raise the attractiveness of bio-ethanol in terms of net social benefit; however, it specifies to only in case that bio-ethanol production systems are sustainably managed.
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