Exergy Analysis And Life Cycle Assessment Of Producing Ethylene Glycol From Coke Oven Gas

Only 20%of COG（Coke Oven Gas）,which is one of the by-product in coke production and mainly composed of H₂,CH₄and so on,is served as fuel annually.Therefore,the recovery and utilization of COG can not only avoid the waste of resources effectively,but also decrease the results of environmental pollution.EG（Ethylene glycol）which is an important raw material in chemical industry,and has great application prospect but dependence on imported massive.In addition,compared with other COG recovery and utilization methods,EG production from COG is mature technology and great prospect of development.For this reason,the main contents of this thesis are as follows:Based on the analysis of reaction mechanism and kinetics,the process of EG production was simulated and optimized by using Aspen Plus simulation software.The simulated showed that the quality and yield of EG was 99.99%（polyester grade）and200kt/a;the yield of by-product DMC（Dimethyl Carbonate）,ethanol and MG（Methyl glycolate）are 39.3kt/a,22.2kt/a and 17.6kt/a.The simulation results of EG production from COG are in good agreement with the literature data which indicated that the model is correct and reasonable.Secondly,based on the Kameyama-Yoshida environmental state model and Hinderink calculation method,the exergy analysis of high energy consumption section（methane reforming and EG production）in EG production from COG was calculated.Results showed that the exergy efficiency of the methane reforming and EG production section accounted for 85.32%and 79.98%,the total exergy loss is 115.091MW,356.748MW,and the main unit of exergy loss is found as the heat exchange unit.Finally,the life cycle assessment（LCA）process model of EG production from COG is established by using the Aspen simulation results.Results showed that the EG production section which is accounted for 72.94%played a significant role on the total LCA environmental impacts of system,mainly attribute to the consumption of electricity,and coal coking section contributes only 7.41%.Furthermore,results of LCA indicated that hydrogenation production section which is allocated 55.41%was the dominated unit in the environmental impact.