KINETICS OF DILUTE ACID-HYDROLYSIS OF CELLULOSE ORIGINATING FROM MUNICIPAL SOLID-WASTES

Kinetics of dilute acid hydrolysis of cellulose originating from municipal solid wastes (MSW) were determined on the basis of experimental results from a hydrolysis batch reactor. pH values were used as a measure for the acidity instead of the usual sulfuric acid concentration (weight percent), which was found to be unsuitable due to the significant effect of the neutralizing capacity of lignocellulosic materials. The hydrolysis experiment results were used to determine the rate constants of cellulose and glucose hydrolysis (k1 and k2) together with the glucose yield (Y). The kinetic parameters of the process (E1, m, k1o and E2, n, k2o) were then calculated. These results led to the calculation of the maximal glucose yields (Y(max)) and the corresponding reaction times (t(opt), which were found to be directly dependent on the experimental conditions (temperature and pH) and could be expressed by a new set of equations. It was found that within the range of hydrolysis conditions studied (pH 0.34-0.85 and temperature 200-240-degrees-C), the best conditions for MSW hydrolysis were the most severe ones: pH 0.34 and temperature 240-degrees-C. Under these conditions, a glucose yield of 54.30% was achieved at a reaction time of 4.6 s.