(381c) Techno-Economic Analysis of Mixed Alcohol Production Through Hydrogenation of Volatile Fatty Acids Derived From Seaweed

Recently, there has been growing interest regarding use of seaweeds as biomass feedstocks. On bioethanol production from seaweeds, there are two main obstacles that make it hardly applicable in industrial scale. First, high seaweed price greatly effects the economy of bioethanol production from seaweeds. Developing mass cultivation sites and enhancing seaweeds cultivation procedures would be necessary steps to address this problem. Secondly, ethanol production from seaweeds has relatively low yield. Research on finding new enzyme, bacteria, or yeast, which are capable of fermenting a wider range of sugars produced by seaweed saccharification, can be the only solution. An alternative way to produce bioethanol would be finding new substitute processes that produce ethanol with higher conversion and lower final ethanol price.

Volatile fatty acids (VFAs) can be easily produced from seaweeds. They have higher conversion yields in comparison with those of direct ethanol production. VFAs can easily be converted to ethanol by hydrogenation. For these reasons, this study develops a techno-economic model to survey economy of VFAs production from seaweeds followed by hydrogenation to produce bioethanol.

Our previous study on direct bioethanol production from seaweed showed that the maximum dry seaweed price (MDSP) should be lower than 160 US$ per ton to allow ethanol production economically viable. This study also calculates the MDSP for this process and survey possible opportunities to improve the economy of ethanol production.

The whole process was designed and simulated in Aspen plus V7.3 and then sent to aspen process economic analyzer for economical evaluations. Plant scale-up effects on the economy of plant were also examined in detail.