Process Optimization Of Preparing N,N-dimethylacetamide Via Reaction Distillation

N,N-dimethyl acetamide (DMAC) is an aprotic organic solvent with high boiling point and strong polarity, having the ability to dissolve, good stability, low volatility, hard to be hydrolyzed, hard to change and low corrosion. It can be widely used in the fields of petroleum processing and industrial organic synthesis. At present, the demand of N,N-dimethyl acetamide consumption from the domestic acrylic fiber industry and spandex industry accounts for the most part. And with the development of the chemical industry, N,N-dimethyl acetamide will maintain a broader prospect for development and application.In this paper, on the basis of the catalytic condensation method, catalytic reactive distillation technology is used to synthesize N,N-dimethyl acetamide at the atmospheric pressure, with dimethylamine and glacial acetic acid as raw materials, zinc chloride as the catalyst. The partial coupling of the reaction with distillation was achieved by this process, the reaction and separation were operated simultaneously. Thus the process was simplified, together with the reactant conversion, the product selectivity and the reaction yield developed. The reaction products obtained contain a small amount of acetic acid, which no longer need to be neutralized, filtered and distilled. The high-purity DMAC product can be obtained directly by the conventional distillation, meeting the requirements of each application area.The laboratory and pilot tests were taken to determine the optimization of process parameters of DMAC synthesized by catalytic reaction distillation. Qualified pilot products were produced with good application results, reaching the requirements of the users. The preliminary design of the device on DMAC industrial production with10,000tons/year was completed based on pilot datas, which will lay the foundation of industrial projects.The process of this technology is simple and reasonable, with low production costs, high product quality and less pollutants. The industrial production plant of economic scale is used to produce DMAC products, which will occupy the domestic market with low costs and high quality. Some products will be available for the acrylic device in Jilin and other places nearby, so as to optimize the allocation of regional resources, creating the significant economic and social benefits for enterprises.