Kinetics Modeling of a Naphtha Thermal Creacker

• Main Authors: Yi-Lung kuo, 郭議隆
• Other Authors: Dr.Hsi-Jen Chen
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/71226559243742824866

碩士 === 淡江大學 === 化學工程學系 === 89 === The pyrolysis is a major technique for production of olefins in the petrochemical industry and ethylene has been the most basic and important building block in the industry today. The main source of ethylene in Taiwan is derived from naphtha cracking. Pyrolysis means thermal cracking of hydrocarbon feedstocks by means of heating intensively. The basic theory behind pyrolysis is the scission and coupling, hydrogen abstraction along with decomposition and addition of hydrocarbon molecules at high temperature. As a result, pyrolysis of hydrocarbon forms many products. In addition to olefins, aromatics and pyrolysis gasoline are also important products from naphtha cracking plants.In this thesis, we propose a mathematical model of the naphtha cracker — the core of the entire process. In the model, naphtha reaction kinetics, material/energy balance of cracked gases, heat transfer mechanisms such as radiation in the cracking furnace, heat conduction and convection of tube, pressure drop across the tubular reactor were all considered. The model leads to a set of nonlinear ordinary differential equations, including twenty crack-gas mass balance plus overall energy and pressure drop differential equations. By means of the model, we are able to solve and predict product distribution in the exit coil numerically. An application is also made to predict the correlation between the olefinic products and operating variables by developing various yield models.