Techno-economic analysis of biofuels from high moisture feedstock via hydrothermal liquefaction and anaerobic digestion
Mitch Amundson, Mark Mba Wright
The purpose of this study is to develop an economic model that analyzes biofuel production from high moisture feedstocks. In this preliminary study, corn silage, sweet sorghum and giant miscanthus are used as feedstocks and converted by means of hydrothermal liquefaction (HTL) and hydroprocessing or anaerobic digestion (AD) and Fischer Tropsch (FT) upgrading or methanol to gasoline (MtG) upgrading. Results yield a comparative economic analysis of mass and energy balances for each scenario.
The US Department of Energy determined that economic biofuel production advises that the logistics cost do not exceed 19% of the final ethanol production price ($/gge). Logistics cost include: harvesting, baling/storage, handling, transportation and preprocessing. For most thermochemical conversion pathways a dry feedstock (<10wt% moisture) is essential to obtain reasonable efficiencies. Feedstock drying is an energy intensive and expensive process so conversion methods where moisture content is not a factor may hold the answer to reducing biofuel prices.
This comparison study analyzes the economic viability of various plant sizes, feedstocks, harvesting and storage methods, conversion processes and upgrading technologies. The model shows that for most scenarios the logistic cost is less than the target 19% of total fuel price and fuel prices are within a reasonable range. After preliminary studies, results show potential promise in high moisture feedstock biofuel production.
See more of this Group/Topical: Sustainable Engineering Forum