| As an important chemical raw material,styrene can be used to produce polystyrene resin,acrylonitrile butadiene styrene resin,styrene butadiene rubber and styrene butadiene latex.For a long time,the self production capacity of styrene in China is insufficient,and the domestic supply mainly depends on importing from abroad.With the continuous commissioning of new styrene plant in China,the styrene production capacity will gradually be saturated.Therefore,reducing the cost of raw materials,reducing the consumption of energy and material consumption and improving the advanced technology are the main measures to improve the economic efficiency of enterprises.Based on the ethylene rich gas-liquid phase ethylbenzene process,this paper discusses the influence of ethylene rich gas raw materials with different ethylene concentration and composition on the process flow response and unit energy consumption level.Firstly,Aspen Plus software is used to model the ethylbenzene styrene combined unit of a petrochemical enterprise,including liquid-phase alkylation reaction unit,ethylbenzene distillation unit,ethylbenzene dehydrogenation reaction unit,tail gas and condensate treatment unit,styrene distillation unit,etc.the simulation results are compared with the design values.The error between the design values and simulation values of various key data results is less than 5%,which ensures the accuracy of the model.The separation sequence of ethylbenzene distillation section and styrene distillation section was compared and analyzed,and the separation process with the best economic benefit was selected.The response of the process flow to the raw material is explored.It is concluded that the suitable concentration range of ethylene raw material for ethylene rich gas-liquid phase preparation of ethylbenzene is 70% or more,and does not contain light end components such as hydrogen and methane.By making full use of the pressure energy in the process of ethylene rich gas-liquid phase ethylbenzene production,a flash separation device for ethylene rich gas to ethylbenzene is developed,and the sensitivity analysis of various operating parameters is carried out,which reduces the operating cost of the flash process by 21%,reduces a certain amount of equipment cost,and effectively improves the economic benefits of the enterprise.Similarly,the multi-stage absorption process with stronger adaptability to raw materials is modeled,the sensitivity of key operating parameters is analyzed,and the adaptability to ethylene raw materials from different sources is analyzed according to its process characteristics.Compared with the ethylene rich gas-liquid phase process,it is concluded that the multi-stage absorption process is more suitable for ethylene raw materials with less than 70% and light end components. |
