臭氧氧化法制备晶体乙醛酸的清洁生产工艺

Cleaner Productin Process for Preparation of Crystalline Glyoxylic Acid by Ozone Oxidation Process

以顺丁烯二酸酐为原料、水为溶剂,用臭氧氧化法制备晶体乙醛酸的最佳条件为:反应时间8 h,反应温度30℃,顺丁烯二酸质量分数30%。减压蒸馏出的甲酸水溶液可循环利用。中试试验结果表明,合成的晶体乙醛酸中乙醛酸的质量分数为97.2%～97.7%,达到了市售工业乙醛酸的要求。晶体乙醛酸的收率为95.5%～96.1%,熔点为51～53℃,用红外光谱技术对其结构进行表征的结果表明,晶体乙醛酸的红外谱图与乙醛酸标准谱图基本吻合。该工艺过程无三废污染,可实现清洁生产。

Crystalline glyoxylic acid was prepared by ozone oxidation process using maleic anhydride as raw material and water as solvent. The optimum conditions are as follows： reaction time 8 h, reaction temperature 30 ℃, mass fraction of maleic acid 30%. The formic acid solution from vacuum distillation process can be reused. The results of pilot test show that the mass fraction of glyoxylic acid in the crystalline glyoxylic acid product is 97. 2% - 97. 7%, which can meet the standards for industrial glyoxylic acid on sale. The yield of crystalline glyoxylic acid is 95.5 % - 96.1%, and its melting point is 51 -53℃. The structure of the product was characterized by FT-IR and the results show that the IR spectrum of crystalline glyoxylic acid is almost as same as that of the standard IR spectrum. This process is a cleaner production process with no pollution.