Environmental sustainability assessment of bio-ethanol production in Thailand
Thapat Silalertruksa, Shabbir H. Gheewala*
The Joint Graduate School of Energy and Environment, King Mongkut’s University of Technology Thonburi, 126 Prachauthit Road, Bangkok 10140, Thailand
a b s t r a c t
Bio-ethanol is playing an important role in renewable energy for transport according to Thai government policy. This study aims to evaluate the energy efficiency and renewability of bio-ethanol system and identify the current significant environmental risks and availability of feedstocks in Thailand. Four of the seven existing ethanol plants contributing 53% of the total ethanol fuel production in Thailand have been assessed by the net energy balance method and Life Cycle Assessment (LCA). A renewability and net energy ratio portfolio has been used to indicate whether existing bio-ethanol production systems have net energy gain and could help reduce dependency on fossil energy. In addition, LCA has been conducted to identify and evaluate the environmental hotspots of ‘cradle to gate’ bio-ethanol production. The results show that there are significant differences of energy and environmental performance among the four existing production systems even for the same feedstock. The differences are dependent on many factors such as farming practices, feedstock transportion, fuel used in ethanol plants, operation practices and technology of ethanol conversion and waste management practices. Recommendations for improving the overall energy and environmental performance of the bio-ethanol system are suggested in order to direct the bio-ethanol industry in Thailand towards environmental sustainability.
Keywords:
Bio-ethanol
Cassava
Molasses
Life cycle assessment
Renewability,
Net energy balance
a r t i c l e i n f o
Article history:
Received 30 October 2008
Received in revised form
14 July 2009
Accepted 8 August 2009
Available online 27 August 2009
