Optimization Of Separation Process Of Vinyl Acetate By Acetylene

In the production of vinyl acetate by acetylene,the mixed gas produced from the reaction reactor is separated and removed by the acetylene separation section and vinyl acetate refining section,and the vinyl acetate(main product)and acetaldehyde(by-product)which meet the product specifications.The main purpose of acetylene separation section is to recover a large amount of unreacted raw material acetylene and send it to the synthetic section for recycling.The quality of circulating acetylene is the main index to evaluate the technology of acetylene separation section.Vinyl acetate refining section is to further separate the reaction liquid after the recovery of raw material acetylene in the separation section,remove the impurities,the resulting product is vinyl acetate and produced acetaldehyde by side,and recycle acetic acid in the system,the quality of the product vinyl acetate is the main indicators to evaluate the quality of refining process of vinyl acetate process,the second is the quality of the by-products of acetaldehyde and the acetic acid.In this paper,the process of vinyl acetate by acetylene process was analyzed,the influence factors of circulating acetylene quality in acetylene separation section and the quality of vinyl acetate products in vinyl acetate refining section are discussed emphatically,and discussed the technological process and how to optimize the scheme to improve the quality of circulation acetylene and vinyl acetate,the reasonable and feasible measures are put forward,then the chemical process simulation software Aspen plus was used to simulate the optimization scheme.Aspen plus simulation results show that,in the optimization scheme,after the improvement and optimization of the separation of acetylene section,the energy consumption is saved,the proportion of the harmful substances acetaldehyde and crotonaldehyd in the circulation acetylene is reduced,the quality of circulating acetylene is improved,the catalyst poisoning phenomenon has been effectively alleviated,the life span of catalyst and the product output is also improved.On the basis of the process improvement of the acetylene separation section,the separation sequence of vinyl acetate multi-component distillation was improved in the vinyl acetate refining section,and the vinyl acetate which conforms to the quality index of superior products was obtained.Meanwhile,the heat pump distillation technology was adopted in the acetic acid column,which reduced the energy consumption of the single column and had obvious energy-saving effect.