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| PDF : |  15030114.pdf |
| title(En) : | Effect of the Thermal Treatment on Wood Hemicelluloses. III. Kinetic Examination of the pyrolysis of Xylan (in English) |
| author(En) : | Kazumasa Shimizu, Fumiyuki Teratani, Kango Miyazaki |
| information : | Mokuzai Gakkaishi 15(3), 114-119 (1969) |
| assort : | Original Article |
| summary(En) : | Kinetic parameters such as reaction order n, energy of activation E and frequency factor A for the pyrolysis of xylan under vacuum were determined by means of dynamic thermogravimetric analysis (CHATTERJEE method) and isothermal analysis (CHATTERJEE-CONRAD method). The result obtained by CHATTERJEE method indicated that four reaction stages were involved in the range from 200° to 300°C. The initial stage accompanied by weight loss up to 10% was controlled by zero-order kinetics and E was 39.9 kcal/mol. The subsequent first-order reaction was divided into three stages. In the first stage, E was 29.6 kcal/mol, in the second one, E = 17.7 kcal/mol and in the last, E = 43. 6 kcal/mol. The investigation by isothermal method (204°, 216° and 221°C) showed the existence of two first-order regions. The values of E were 25. 7 kcal/mol and 21.9 kcal/mol, respectively. Further, another zero-order step was revealed in the range from 200°C to the isothermal temperature in which about 15% of total weight was lost, and yielded E = 45.6 kcal/mol by plotting the temperature dependency of the rate of weight loss. Assumption of the pyrolytic reaction mechanisms of xylan have been proposed through these results. |