Abstract:

Spent catalyst with 1.7% of carbon content was prepared as the material for kinetic study. The intrinsic reaction kinetics of partial oxidation of coke was investigated at the reaction temperatures ranging from 510℃ to 780℃. The kinetic parameters of carbon conversion were obtained for various reaction conditions. For the carbon-water system, when the gasification of carbon took place below 780℃ with present of excessive carbon, the gasification of coke followed zero-order reaction, with the activation energy and the frequency factor of 161.23 kJ/mol and 116.2 s-1, respectively. For the carbon-oxygen-water system, when oxygen and water were excessive, the coke gasification in the temperature range of 510-665 ℃ followed first-order reaction with the activation energy and the frequency factor of 38.22 kJ/mol and 1.37 s-1; when the carbon and water were excessive, the oxygen consumption followed first-order reaction, with the activation energy and frequency factor to be 79.74 kJ/mol and 311 712 s-1, respectively. Experimental results indicated that the formation of CO was mainly from the reaction of carbon and oxygen at the reaction temperatures below 800 ℃. The relationship between the value of λ and T is λ=8.31e-16 736/(RT)], where λ is the molar ratio of CO to CO2 from the primary reaction of carbon and oxygen.

Key words: coke, partial oxidation, CO, intrinsic reaction kinetics