Manufacture of fermentable sugar solutions from sugar cane bagasse hydrolyzed with phosphoric acid at atmospheric pressure

Abstract

Sugar cane bagasse, a renewable and cheap bioresource, was hydrolyzed at 100 degreesC using phosphoric acid at different concentrations (2, 4, or 6\%) and reaction times (0-300 min) to obtain fermentable sugar solutions, which have a high concentration of sugars (carbon source for microorganism growth) and a low concentration of growth inhibitors (acetic acid and furfural). Xylose, glucose, arabinose, acetic acid, and furfural were determined following the hydrolysis. Kinetic parameters of mathematical models for predicting these compounds in the hydrolysates were obtained. Derived parameters such as efficiency of hydrolysis or purity of hydrolysates were considered to select as optimal conditions 6\% phosphoric acid at 100 degreesC for 300 min. Using these conditions, 21.4 g of sugars L-1 and <4 g of inhibitors L-1 were obtained from the hydrolysis with a water/solid ratio of 8 g of water g(-1) of sugar cane bagasse on a dry basis.