Coke Deposition Influence Based on a Run Length Simulation of a 1,2-Dichloroethane Cracker

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• 作者：Chaochun Li ; Guihua Hu ; Weimin Zhong ; Wangli He ; Wenli Du ; Feng Qian
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2013
• 出版时间：December 11, 2013
• 年：2013
• 卷：52
• 期：49
• 页码：17501-17516
• 全文大小：885K
• 年卷期：v.52,no.49(December 11, 2013)
• ISSN：1520-5045

文摘

A full cycle of an industrial ethylene dichloride cracker is simulated. Given the intense heat coupling between the furnace and the reactor, the cracker is divided into two parts: the furnace model and the reactor model, with heat flux and flue gas temperature profiles connecting the two models. A radical mechanism with coke formation is adopted to describe the EDC cracking reactions with 24 reaction equations and 31 components. In the full cycle simulation, two important aspects, namely, CCl<sub>4sub> concentration and fuel gas allocation, are investigated to understand the overall benefits of the whole operation cycle. Addition of the promoter CCl<sub>4sub> to EDC raw material can improve EDC conversion. However, this process aggravates the coking reaction, which causes the sharp deterioration of the cracking performance and the shortening of the running cycle. On the other hand, the fuel gas allocation factor facilitates analysis of the fuel gas allocation strategies. Increasing the fuel gas amount at the furnace bottom can effectively improve the heat transfer efficiency of the EDC cracker. In particular, this process enhances heat transfer at the end of the tubular reactor, which improves the EDC conversion. However, coke deposition greatly shortens the run cycle. A comprehensive analysis shows that the concentration of the CCl<sub>4sub> promoter should be controlled at 100 ppm wt % and the fuel gas allocation factor should be maintained at 0.36 to guarantee the overall economic benefits of the EDC cracker in the full operation cycle.