Thapat Silalertruksa

Long-Term Bioethanol System and Its Implications on GHG Emissions: A Case Study of Thailand

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 countrys 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.

Implications of the biofuels policy mandate in Thailand on water: the case of bioethanol.

The study assesses the implications of the bioethanol policy mandate in Thailand of producing 9 M litre ethanol per day by 2021 on water use and water deprivation. The results reveal that water footprint (WF) of bioethanol varies between 1396 and 3105 L water/L ethanol. Cassava ethanol has the highest WF followed by molasses and sugarcane ethanol, respectively. However, in terms of fresh water (especially irrigation water) consumption, molasses ethanol is highest with 699-1220 L/L ethanol. To satisfy the government plan of bioethanol production in 2021, around 1625 million m(3) of irrigation water/year will be additionally required, accounting for about 3% of the current active water storage of Thailand. Two important watersheds in the northeastern region of Thailand are found to be potentially facing serious water stress if water resources are not properly managed. Measures to reduce water footprint of bioethanol are recommended.

A comparative LCA of rice straw utilization for fuels and fertilizer in Thailand.

Life cycle assessment of four rice straw utilization systems including; (1) direct combustion for electricity, (2) biochemical conversion to bio-ethanol and biogas, (3) thermo-chemical conversion to bio-DME, and (4) incorporation into the soil as fertilizer have been conducted to compare their environmental performances. The results showed that per ton of dry rice straw, the bio-ethanol pathway resulted in the highest environmental sustainability with regards to reductions in global warming and resource depletion potentials. Rice straw bio-DME was preferable vis-à-vis reduction in acidification potential. Rice straw electricity and fertilizer also brought about several environmental benefits. The key environmental benefit of rice straw utilization came from avoiding the deleterious effects from burning straw in situ in the field. Recommendations for enhancing environmental sustainability of rice straw utilization for fuels and fertilizer are provided.

Food, Fuel, and Climate Change

This study evaluates the sustainability of biodiesel for transport in Thailand in terms of the availability of fresh fruit bunches (FFB) and crude palm oil (CPO) supply to satisfy the future demands for food and fuel, and the contribution of palm biodiesel to mitigating climate change if biodiesel induces land‐use change (LUC). Five land conversions including rubber, cassava, paddy field, set‐aside land, and forest land to oil palm are considered along with their displacement effects to other land types to evaluate the greenhouse gas (GHG) emissions associated with the direct and indirect land‐use impacts. The net feedstock balance reveals that the policy to expand 0.4 million hectare (Mha) for new oil palm plantations accompanied with an increase of FFB yield to 22 megagrams per hectare (Mg/ha) by 2012 would help avoid a CPO shortage; however, this increase in land use needs to be strongly encouraged. The GHG analyses show a wide range of net GHG balances compared to diesel depending on which type of land is converted and which options are used to treat the oil palm wastes. Except for forest land conversion, direct LUC emissions from converting other lands to oil palm will render benefit to the GHG balance of biodiesel. Indirect LUC emissions through crop displacements, however, will generally worsen the balance. Several recommendations are therefore suggested for sustainable palm biodiesel production in the future.

Sustainability Assessment of Palm Biodiesel Production in Thailand

Palm oil is the world’s largest source of edible oil and is recently being promoted to produce biodiesel in South–East Asian countries including Thailand. The impacts of palm biodiesel production and use to the environment and socioeconomic development in Thailand are presented. Substituting palm biodiesel for diesel can result in various positive externalities to the Thai society and economy such as GHG emissions reduction, employment generation, GDP development, and trade balance improvement. However, some potential environmental drawbacks of increased palm biodiesel production in the future such as the increase in eutrophication impact potential and land-use change from forest land to oil palm need to be considered and regulated. Improving the sustainability of palm oil and palm biodiesel industry in the future entails the investigation on the potential exploitation of palm-based biorefinery systems along with the concept of “cascade utilization” to fully utilizing biomass residues and wastes generated from palm oil and palm biodiesel industry.