Kinetic Study and Investigation of Mechanisms Changes in iso and Normal Butane Cracking over HZSM Zeolite

In the present research, kinetics and mechanisms of the catalytic cracking of isomers of butane over H-ZSM-5 zeolite with was investigated. Due to the type of the cracking mechanisms which highly depended upon the various operating conditions including temperature, partial pressure and contact time of the reacting feed, the product composition was hugely variable. According to the prevailing mechanism, the reasons for this variation in the composition of the produced final product might be explained. The two mechanisms, protolytic (mono-molecular) and bi-molecular in paraffin cracking over zeolite which may occur simultaneously were proposed in paraffin cracking. The domination of each mechanism determined the final product composition and completely influenced the products spectrum. The increase in reaction temperature and feed contact time as well as; the decrease in paraffin partial pressure resulted in improvement of protolytic mechanism which ultimately raises the amount of light olefin production.