催化加氢法提高乙二醇的紫外透光率

Catalytic hydrogenation to improve the ultraviolet light transmittance of ethylene glycol

利用自制催化剂研究了催化加氢反应提高酯交换反应合成碳酸二甲酯工艺中副产物乙二醇的紫外透光率(UV值)问题。结果表明,在温度为110℃,催化剂质量为乙二醇质量的3%,氢压为1.0 MPa,反应时间为3.5 h的反应条件下,得到乙二醇在波长为220、275 nm和350 nm的UV值,分别由原来的1.3%、16.1%和92.6%平均提高到76.5%、94.9%和99.8%,质量达到了最新的国标要求。根据加氢反应前后乙二醇的GC-MS分析结果,可以判定影响乙二醇UV值的杂质主要是N,N-二甲基甲酰胺和2-氯乙醇。

The catalytic hydrogenation over self-made catalyst is studied to improve the UV transmittance of ethylene glycol produced by transesterification of ethylene carbonate and methanol. The UV transmittance of ethylene glycol at 220 nm,275nm,350 nm is averagely increased from 1. 3%,16. 1%,92. 6% to 76. 5%,94. 9%,99. 8%,respectively,under the following conditions： 110℃ of temperature,3% of catalyst,1. 0 MPa of H2 pressure and 3. 5 h of reaction time. The quality of ethylene glycol can meet the current GB standard requirements. According to the GC-MS analysis of ethylene glycol before and after the hydrogenation,it proves that the impurities which influence the UV transmittance of ethylene glycol are mainly N,N-dimethylformamide and 2-chloroethanol.