Valorization of lignin from biofuel production is the key to developing biorefinery technologies for sustainable and economic utilization of lignocellulosic biomass. Here we present isolating lignosulfonate from the spent liquors of Sulfite Pretreatment to Overcome the Recalcitrance of Lignocelluloses (SPORL)-pretreated lodgepole pine and Douglas-fir forest residue as a dispersant for coal water slurry. The two SPORL pretreatments were conducted at a pilot scale and resulted in very high

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... yield from the pretreated biomass. Therefore, demonstrating the commercial utility of these lignosulfonates has practical significance. Main results: The two isolated biorefinery lignosulfonates (LSs), Na-LS and Ca-LS, both had a molecular weight of approximately 9000 Da. Fundamental lignin properties such as chemical structure, functional groups were analyzed. The two LSs showed slightly better to equal performance in modifying CWS rheology than a commercial dispersant naphthalene sulfonate formaldehyde condensate (FDN), despite they were less sulfonated than FDN. Conclusions: The practical importance of this study is that the pilot-scale pretreatments that produced the two LSs also produced excellent bioethanol yields at high titer without detoxification and washing. This suggests SPORL pretreatment is a promising technology for economic bioconversion of under-utilized woody biomass.