Study On Process Simulation And Improvement For Quench System In Ethylene Plant

Quench system which directly connects cracking unit and compression unit, is an important part in ethylene plant, its performance has important influence on ethylene plant, and it is the priority part for revamping and enlarging ethylene plant's scale. As the first step of pyrolysis gas from cracking furnace, quench system has the feature of large handing capacity and large heat recovery. On the basis of examples from the domestic, this article simulated by means of the process simulation software PRO/II, and studied that the impact of parameter on the quench system. Finally, the proposal about the improvement of quench system is brought up.As the complexity feed-in of quench system in ethylene unit, in this dissertation, the feed composition is obtained by"backing out"method. The feed of quench system is the sum of treated pyrolysis gas, gasoline, diesel and fuel oil which are also the products of quench system. As pyrolysis gas is mostly composed of petroleum hydrocarbon and water, the considerably accurate results can be obtained by using the equation of state SRK. Meanwhile, some proper assumption and predigestion are also concluding in this article.Based on the exact simulation of quench system, this article has some deep research about the parameter impact on the quench oil heat and the quality of product. Some conclusions about directing the industrial process are acquired by these analysis.On the foundation of the feature of the present quench system in ethylene plant, after analyzing the insufficiency of energy recovery and dilution stream recovery, this simulation has some credible improvements on the former process. The new process could recover much high potential energy, reduce the MP stream interpolation of diluting steam generation system, and finally reduce the dissipation of energy in ethylene plant.In a word, the research conclusions have considerable significance on advancing the level of plant operation, reclaiming high potential energy and reducing dissipation of energy.