(583e) Hydrolysate De-Acidification Using Resin-Wafer Electrodeionization

          Dilute acid pretreatment of lignocellulosic feedstock offers an economic route for the extraction of fermentable sugars from non-food biomass for biofuel production by bioconversion.  However, removal of acids from the hydrolysate is a critical step to ensure optimal conditions for the subsequent bioprocessing/conversion steps, i.e., enzyme hydrolysis of the cellulose to release C6 sugars and for the final fermentation to produce biofuel.  The removal (conditioning step) of inorganic and organic acids (released together with C5 sugar molecules from the hemicellulose) after the acid treatment stage poses a great economic challenge to the overall biofuel production cost.  To address this challenge, we used a proprietary resin wafer electrodeionization (RW-EDI) technology to remove both the inorganic and organic acids in a single step.  Preliminary process economic analysis indicates that the easily scalable and small foot-print unit operation of RW-EDI can offer an economic and viable means of addressing the hydrolysate conditioning challenge.  Selective removal of inorganic acids and organic acids was demonstrated when appropriate operation conditions were employed for the RW-EDI operation.  This unique feature makes possible the separate recovery of both inorganic acid (e.g., sulfuric acid) and organic acids, which act as fermentation inhibitors, so that the inorganic acid can be recycled to the dilute acid pretreatment stage.  The RW-EDI also provides an option to remove other fermentation inhibitor such the furfural and hydroxy methyl furfural (HMF) during the hydrolysate conditioning. In this presentation, process design and performance of hydrolysate de-acidification using RW-EDI will be discussed.  Pilot-scale demonstration of technology viability using synthetic hydrolysate will be also presented along with preliminary assessments of economic and process benefits.