Reactivity upon gasification of residues from the sugar cane industry

P. J. VILLEGAS AGUILAR; P. R. BONELLI; M. C. CASSANELLO; A. L. CUKIERMAN

SHANGAI, CHINA

Congreso; Fifth Asian Pacific Symposium on Combustion and Energy Utilization (5th. APISCEU); 1999

SHANGAI, CHINA

Gasification with low oxygen concentrations of pyrolized residues, chars, from the sugar cane industry is examined by isothermal and non-isothermal thermogravimetric analyses. Particularly, chars of sugar cane bagasse (SCB) and the leaves, generically called sugar cane agricultural residues (SCAR), and mixtures of these chars are employed for the experiments. Results are represented by a model that assumes a one step global reaction, with a reduced number of adjustable parameters, which are estimated from the isothermal experiments performed within the temperature range 623-773 K. Intraparticle diffusional effects become significant for temperatures higher than 773 K. SCAR char is found to be more reactive than the SCB char, in correspondence with the trend between intrinsic reactivity and samples carbon content reported in the literature. This difference in reactivity has an influence over mixtures behaviour and is reflected in the estimated activation energy values. Under kinetically controlled conditions, estimated parameters of intermediate values between those obtained for chars of SCB and SCAR characterize gasification of a mixture of 70 % (w/w) in bagasse char. Reactivity of each char and several mixtures are also analyzed from the non-isothermal experiments, carried out from ambient temperature up to 873 K.