Pilot-scale hydrothermal pretreatment and optimized saccharification enables bisabolene production from multiple feedstocks

Abstract

To date, information on biomass deconstruction and advanced biofuels production using pilot-scale pretreatments is scarce and typically derived from single feedstocks, making comparisons complicated. This work evaluates the effect of subjecting four different feedstocks (agave bagasse [AG], corn stover [CS], sugarcane bagasse [SC] and wheat straw [WS]) to pretreatment at 180 °C for 20 min in a 200 kg day⁻¹ pilot-scale continuous tubular reactor constituted by three sequential stages (compression, autohydrolysis and steam explosion). Correlations between the structural changes and differences in digestibility on pretreated biomass were determined. It was determined that xylan removal by pretreatment generated more crystalline and energy dense materials, with higher lignin content and S/G ratio. Optimal reaction conditions for enzymatic saccharification of pretreated feedstocks at lower enzyme doses generated glucose conversions up to 80%. Finally, it was demonstrated that the yeast Rhodosporidium toruloides was able to grow in all hydrolysates, exhibiting simultaneous C₅ and C₆ sugar consumption and bisabolene production.