(412f) Techno-Economic Analysis of An Integrated Catalytic Process for Conversion of Lignocellulosic Biomass to Straight Chain Hydrocarbons

Depleting fossil fuel resources, increasing concerns over environmental effects arising from combustion of these fossil fuel resources and growing global energy needs have driven today’s research towards renewable energy technologies. Because of its abundance [1-2], biomass is considered as the most appropriate long-term alterative to fossil carbon. However, a large-scale transition to lignocellulosic fuels is constrained by the economic and technological challenges associated with biomass conversion processes to “drop-in” fuels.

Here, we present a technoeconomic analysis of an integrated catalytic approach toward the production of jet fuel components and commodity chemicals from hardwood feedstock. Our technoeconomic analysis is based on experimental results obtained from a three year study funded by DARPA SurfCat.  The first step in this process is the conversion of the biomass into an aqueous hemicellulose stream.  The aqueous hemicellulose stream is then converted into furfural.  The furfural could then be further converted into a petroleum quality feedstock through aldol-condensation, hydrogenation/hydrocycloaddition and hydrodeoxygenation steps.  The solid cellulose stream is converted into Levulinic Acid (LA). LA is then hydrogenated to gamma Valero lactone (GVL).  GVL is further converted into olefins and then oligomerized to make jet and diesel range hydrocarbons.   We summarize the key technical challenges associated with process integration and review the most promising approaches for the production of mixed alkanes from lignocellulose.

We carry out techno-economic analysis of the entire process for a biorefinery processing 1983 MT/day of red maple feedstock.  The process would produce 30 million gallons of jet and diesel fuel range hydrocarbons per year along commodity chemicals (such as acetic acid and HMF) as by-products. Laboratory data was used to estimate the material and energy balances for this process.  A detailed process flow sheet was obtained using ASPEN and used to size the process equipment. Using a conceptual process design approach developed by Douglas [3], we estimate the overall economics of the process. From this preliminary techno-economic analysis, we calculate minimum selling price of the jet and diesel fuel. Our initial calculations have shown that jet fuel selling price of $4.06 per gallon can be obtained using this process. Through this analysis, we identify cellulose deconstruction to LA and decorboxylation for olefin formation as the most expensive steps in terms of reactor costs. Here, we present detailed mass and energy balances for the entire process and provide directions for future research in this area.

References:

[1] G. W. Huber and B. E. Dale, Scientific American, 2009, 301, 52-59.

[2] Perlack, R. D.; Wright, L. L.; Turhollow, A. F.; Graham, R. L.; Stokes, B. J.; Erbach, D. C. Biomass as Feedstock for a Bioenergy and Bioproducts Industry : The Technical Feasibility of a Billion-Ton Annual Supply; US Department of Agriculture (USDA) and US Department of Energy (DOE): April 2005.

[3] Douglas JM. Conceptual design of chemical processes: McGraw-Hill; 1988.