(507d) TEA/LCA of Integrated Processing of Corn Stover for Fuels and High Value Products

Worldwide, at least ½ billion-ton corn stalk or stover is generated per year. An integrated processing approach comprised of biochemical and hydrothermal technologies is developed to process corn stover into high value products that can be sold to generate revenue and offset the fuel cost. Corn bales were pre-processed at the Biomass Feedstock National User Facility (BFNUF) and the obtained pulverized corn stover (low and high ash content) were biochemically treated to obtain unhydrolyzed solids (UHS). Hydrothermal liquefaction (HTL) of UHS was performed to produce hydrochar, phenols and lactic acid. Hydrochar was further valorized into porous carbon, which was used for the energy storage application. Process engineering calculations and scale-up was performed for 1 tpd feedstock throughput. Technoeconomic analysis (TEA) and life-cycle analysis (LCA) were carried out considering optimized integrated processing. Production rate of high value-added products such as high value carbon, phenols and carboxylic acids was included in the process economics calculations. Using ASPEN plus modeling, the integrated process was scaled up to achieve a fuel cost goal of $2 gge.