Stability improvement of the Nieuwland catalyst in the dimerization of acetylene to monovinylacetylene |
| |
Authors: | Jianguo Liu Yizan Zuo Minghan Han Zhanwen Wang Dezheng Wang |
| |
Institution: | Department of Chemical Engineering,Tsinghua University,Beijing 100084,China |
| |
Abstract: | In the process of dimerization of acetylene to produce monovinylacetylene (MVA),the loss of active component CuCl in the Nieuwland catalyst due to the formation of a dark red precipitate was investigated.The formula of the precipitate was CuCl·2C2H2·1/5NH 3,and it was presumed to be formed by the combination of NH 3,C2H2 and Cu]-acetylene π-complex,which was an intermediate in the dimerization reaction.The addition of hydrochloric acid into the catalyst can reduce the formation of precipitate,whereas excessive H+ is unfavorable to the dimerization reaction of acetylene.To balance between high acetylene conversion and low loss rate of CuCl,the optimum mass percentage of HCl in the added hydrochloric acid was determined.The result showed the optimum mass percentage of HCl decreased from 5.0% to 3.2% when the space velocity of acetylene was from 140 h-1 to 360 h-1.The result in this work also indicated the pH of the Nieuwland catalyst should be kept in the range of 5.80-5.97 during the reaction process,which was good for both catalyst life and acetylene conversion. |
| |
Keywords: | monovinylacetylene dimerization reaction Nieuwland catalyst acetylene stability |
本文献已被 CNKI 等数据库收录! |
|