Monitoring and Analyzing Process Streams Towards Understanding Ionic Liquid Pretreatment of Switchgrass (Panicum virgatum L.)

TL;DR: In this paper, the effect of residence time and temperature during ionic liquid (IL) pretreat- ment of switchgrass using 1-ethyl-3-methyl imidazolium acetate was investigated.

Abstract: Fundamental understanding of biomass pre- treatment and its influence on saccharification kinetics, total sugar yield, and inhibitor formation is essential to develop efficient next-generation biofuel strategies, capable of displacing fossil fuels at a commercial level In this study, we investigated the effect of residence time and temperature during ionic liquid (IL) pretreat- ment of switchgrass using 1-ethyl-3-methyl imidazolium acetate The primary metrics of pretreatment perfor- mance are biomass delignification, xylan and glucan depolymerization, porosity, surface area, cellulase ki- netics, and sugar yields Compositional analysis and quantification of process streams of saccharides and lignin demonstrate that delignification increases as a function of pretreatment temperature and is hypothe- sized to be correlated with theapparent glass transition temperature of lignin IL pretreatment did not generate monosaccharides from hemicellulose Compared to untreated switchgrass, Brunauer-Emmett-Teller surface area of pretreated switchgrass increased by a factor of ∼30, with a corresponding increase in saccharification kinetics of a factor of ∼40 There is an observed dependence of cellulase kinetics with delignification efficiency Although complete biomass dissolution is observed after 3 h of IL pretreatment, the pattern of sugar release, saccharification kinetics, and total sugar yields are strongly correlated with temperature