Kinetic Modeling Of Naphtha Thermal Cracking

In this paper, thermal cracking of naphtha was studied. The CCD (central composite design) method was utilized and a set of experiments were designed and carried out. Based on these experiments, the cracking naphtha was studied with the operating conditions as temperature and steam ratio respectively equal to780-830ºc , 0.5-0.9 kg/kg . For this study, the model proposed consist of 27 reactions and 18 species. In the presented model there were 54 unknown parameters(activation energy and rate constant) and considering all the parameters is not simultaneously possibble. To make good agreement between simulation and experimental results, an optimizing objective function was used for the most important components. This function was defined as the sum of squares of differences between simulated results and experimental values.The effects of temperature and inlet steam to naphtha ratio on the major effeluent products were investigated. As the results show, the increase of temperature and steam ratio causes the increase of the yield of major products.

Keywords:

thermal cracking , naphtha , olefin , ethylene