Process Research Of Electro-synthesis From Acrylonitrile To Adiponitrile

In recent years, with the continuous growth of nylon-66 industry, the market demand for adiponitrile(ADN) as the raw material of nylon-66 production is also increasing. At present, the adiponitrile required in our country is depended heavily on foreign imports. Therefore, the study about the production process of ADN is very necessary.The electro-hydro-dimerization(EHD) of Acrylonitrile(AN) is one of the three major synthetic methods of ADN, which is a competitive method for its simple process route and the high yield of ADN. In this paper, the concentration of raw materials and products was detected by the method of gas chromatography(GC) analys is effectively. The electro-synthes is of adiponitrile was conducted in the undivided electrochemical cell with the lead as the cathode and carbon steel as the anode. The effects of the concentration of acrylonitrile, the concentration of tetraethylammonium hydroxide, temperature and p H value were discussed. The result showed that tetraethylammonium hydroxide played a key role on the yield and current effic iency of ADN. The content of AN had a significant impact on the yield of ADN when the concentration of AN was under 5%wt. The yield of ADN was up to 87.38% under the condition of AN 7%wt, current density 1000 A·m-2, temperature 30℃, p H 8 and tetraethylammonium hydroxide 2.5%wt.The designed new electrochemical cell such as the fixed-bed electrochemical cell and the frame type electrochemical cell was applied to the simulation experiment since the undivided electrochemical cell in this paper was unsuited to apply to the industrial production. The results of the electro-synthesis experiment in the fixed-bed electrochemical cell showed that concentration of AN and current density had a more striking impact on the yield of ADN. The yield was 61.92% in the frame type electrochemical cell under the condition of AN 7%wt, the current density 1000 A·m-2 and temperature 40℃. Because of a relatively low yield of AND in the fixed-bed electrochemical cell, a frame electrochemical cell was applied to the electro-synthes is of ADN. The result showed that the yield of adiponitrile was improved to 74.47%,with the cell voltage was below 4.5V, which was much lower than the fixed-bed electrochemical cell in the same electro-synthesis condition.