Chemical-Mechanical Methods for the Enhanced Utilization of Straw

Several mechanical and chemical pretreatments for the enzymatic hydrolysis of cellulose from wheat straw were investigated to provide information not available concerning important bioconversion process steps. While mechanical pretreatments increased enzymatic digestibility to a limited extent, chemical pretreatment with dilute sulfuric acid at 120-160 degree C breaks the lignin-hemicellulose barrier to allow essentially complete hydrolysis of cellulose. Preliminary studies on detergent-aided acid-catalyzed pretreatment indicated that dodecylbenzenesulfonic acid does not have significant effect on the digestibility of straw. Mechanical dewatering studies of treated straw indicated that pressures between 150-200 psig were required to express 80% of the entrained liquor.