(651f) Are Lignocellulosic Feedstocks Commercially Relevant to Make Pure Sugars for Chemical Catalytic Upgrading?

Significant research has been done for upgrading underutilized cellulose, hemicellulose, and lignin of lignocellulosic feedstock using chemocatalytic technologies to fuels and chemicals. One requirement for chemocatalytic upgrading of monomeric/polymeric sugars derived from cellulose and hemicellulose is that these sugars must be nearly pure. However, the currently proposed technologies for the biomass fractionation/pretreatment were developed with a focus of making unpurified sugars for the biocatalytic upgrading. One aim of this work is to select potential biomass pretreatment/fractionation technologies to make pure sugars for chemocatalytic upgrading through two-level screening. Following the two-level screening, the combined autohydrolysis and organosolv (AO) and formic acid pulping technologies were found to be suitable for the effective fractionation of lignocellulosic feedstock to cellulose, hemicellulose, and lignin. The optimal plant scales for the fractionation of lignocellulosic feedstock using the AO and formic acid pulping technologies were determined. The AO and formic acid pulping technologies were simulated using ASPEN Plus to determine the energy consumption for the biomass fractionation technologies. The minimum selling price (MSP) of making purified sugars from a lignocellulosic feedstock was estimated for both AO and formic acid pulping technologies following the discounted cash flow methodology. The estimated MSP of sugars produced via AO and formic acid pulping technologies are $ 0.5 per kg and $ 0.8 per kg, respectively. The requirement of a high liquid to solid ratio is found to be a limiting factor for attaining the target sugar price of $ 0.3 per kg with both AO and formic acid pulping technologies.