Experimental and modeling study of thermal and catalytic cracking of n-decane

摘要

Catalytic cracking of n-decane over a platinum/lanthanum-alumina coated stainless steel tube is experimentally studied to obtain the product distributions and gas yield at a pressure of 1 atm and different temperatures 600, 650 and 700 ℃. The results reveal that the higher the cracking temperature is, the higher the gas yield will be. A detailed micro-kinetic model for cracking of n-decane over a platinum/lanthanum-alumina catalyst is developed to simulate the gaseous product distribution and gas yield. In high temperature catalytic cracking systems, the interactions of gas-phase and surface reactions are very significant phenomena. Thus, the model contains a detailed gas-phase pyrolysis kinetic model along with a surface kinetic model for n-decane cracking over a platinum/alumina catalyst. The gas-phase pyrolysis kinetic model contains 304 species, 1104 reactions and the surface kinetic model contains 52 adsorbed chemical species and 218 reactions. The modeling results of the gaseous product distribution and gas yield are acceptable compared with experimental results. In order to evaluate the contribution of thermal cracking in catalytic cracking, simulation of thermal cracking of n-decane is performed by using the gas-phase pyrolysis kinetic model. The simulation results show that the contribution of thermal cracking in catalytic cracking is increasing with temperature increasing. This work provides insight at the molecular level for the kinetic process of n-decane cracking over a platinum/lanthanum-alumina catalyst.