Comparison of the Potential for Ethanol Production from Rice Straw in Vietnam and Japan via Techno-economic Evaluation

Abstract

This study aimed to compare rice straw ethanol production costs in two countries based on recent production technologies developed in Japan and predict the potential for economical ethanol production in the future. Analysis of cost component distribution and sensitivity showed a trend towards reduced ethanol production cost (PC) in each country. The PCs in the current scenario were 2.28 $/L and 1.45 $/L at a scale of 15 ML/year in Japan and Vietnam, respectively. In Vietnam, the potential for bigger ethanol plants combined with lower feedstock cost can eliminate the majority of investment costs and reduce PC to 1.19 $/L at a scale of 200 ML/year. In Vietnam, enzyme and energy costs are the two biggest cost components of PC. In Japan, the biggest component is the feedstock cost, so increasing ethanol yield is essential to the reduction of PC. In a future scenario, with improvements in production technologies and enzyme activities, the present PC for a scale of 15 ML/year can be reduced to 1.54 $/L and 0.88 $/L in Japan and Vietnam, respectively. In Vietnam specifically, the PC is sharply reduced to 0.45 $/L at a scale of 200 ML/year. This study reveals the high potential for economical production of ethanol from rice straw in Vietnam in the future, and the contrasting difficulties in Japan.