Bioconversionof Beetle-Killed Lodgepole Pine UsingSPORL: Process Scale-up Design, Lignin Coproduct, and High SolidsFermentation without Detoxification.

Mountain pine beetle killed Lodgepolepine (Pinus contortaDouglas ex Loudon) wood chipswere pretreated using an acidic sulfitesolution of approximately pH = 2.0 at a liquor to wood ratio of 3and sodium bisulfite loading of 8 wt % on wood. The combined hydrolysisfactor (CHF), formulated from reaction kinetics, was used to designa scale-up pretreatment on 2000 g wood chips at a relatively low temperatureof 165 °C that reduced furan formation and facilitated high solidssaccharification and fermentation. The pretreated solids and liquorwere disk milled together to result in a biomass whole slurry of 25%total solids. The whole biomass slurry was directly used to conductsimultaneous enzymatic saccharification and combined fermentation(SSCombF) using a commercial cellulase and Saccharomyces cerevisiaeYRH400 without detoxification. A terminal ethanol titer of 47.1g L–1with a yield of 306 L (tonne wood)−1, or 72.0% theoretical, was achieved when SSCombF was conducted atan unwashed solids loading of 18%. The lignosulfonate (LS) from SPORLwas highly sulfonated and showed better dispersibility than a highpurity commercial softwood LS, and therefore has potential as a directlymarketable coproduct. [ABSTRACT FROM AUTHOR]