(663b) Furfural Production As a By-Product of Lignocellulosic Biofuel Process

NREL’s high solids dilute acid steam pretreatment often produces a xylose rich stream with a monomeric xylose concentration in the range of 70~100g/L. The high xylose concentration inhibits the digestibility of biomass during the subsequent whole slurry enzymatic hydrolysis step, leading to a decrease in both glucose and xylose yields. In addition, xylose is not a fermentation-friendly sugar, especially to hydrocarbon fuels. However, xylose can be converted into furfural through dehydration reactions using acid catalysts. At the present time furfural is a high-valued commodity product, where in 2010, the US market average price of furfural was $8.78/gal, over 3 times higher than ethanol’s price. In addition, Furfural is a promising intermediate in the production of hydrocarbons and other chemicals. In this study, alternative pathways to produce furfural as a byproduct of lignocellulosic bioethanol processes were investigated. A delayed decompression flash process was adopted to effectively produce furfural while reducing the degradation of cellulose and furfural to other degradation products. The more severe reaction conditions also significantly reduce the enzyme requirements and improve the digestibility of the residual cellulose. We also evaluated the fermentability of the sugar steam after enzymatic hydrolysis. . This work provided preliminary experimental results to support a techno-economic analysis (TEA) completed using an Aspen plus model modified from the 2011 NREL design base case.