Acid/Sugar Separation Using Ion Exclusion Resins: A Process Analysis and Design

The economic feasibility of using acid hydrolysis to convert agricultural waste products, such as corn stovers, to alcohol is very dependent upon developing a cost effective sulfuric acid-glucose sugar separation process. Presently, an acid/sugar stream from sulfuric acid hydrolysis of cellulose is treated with lime to precipitate the acid as gypsum. This technique not only consumes acid and lime, but also generates waste gypsum that is sent to a landfill. An ion exclusion process to perform acid/sugar separation has been designed using standard resins. Economic analysis based on a process computer model indicates that ion exclusion is 40 % less costly than a lime precipitation process