混合水溶液体系中甲醇和氢氧化钠的分离回收

Separation and recovery of methanol and sodium hydroxide from a mixing aqueous system

利用小分子醇类对氢氧化钠(钾)的选择性溶解性质从固体混合物中分离回收氢氧化钠(钾)是工业上常用的分离手段之一。对甲醇-氢氧化钠-水混合溶液体系中甲醇的真空蒸馏分离工艺进行了研究。采用单因素实验考察真空度、温度、时间、碱浓度对甲醇回收率的影响,并确定初始工艺条件。正交实验确定最佳工艺条件。实验分析表明,真空度为0.08MPa,蒸馏温度为85℃,蒸馏时间为60min时甲醇回收率为99.35%、纯度为95.1%,釜底残留液碱质量浓度为600g/L,甲醇与液碱得到了有效分离。

B y employing the solubility of sodium hydroxide or potassium hydroxide in small molecular alcohols including methanol and ethanol, alcohol extraction is usually used as an approach for separating sodium hydroxide or potassium hydrox- ide from their solid mixture with other water soluble compounds.The separation processes of caustic soda by vacuum distilla- tion of methanol from the CH3OH-NaOH-H20 ternary system were investigated.The conditions for initial processes were de- termined by investigating the effect of single factors, including vacuum degree, temperature,time, and alkali concentration, on methanol recovery.The optimal process conditions were determined with orthogonal experiment.Experimental analysis re- suits showed that the recovery rate of methanol was 99.35% ,the purity of the methanol was 95.1% ,and the residual liquid caustic soda mass concentration was 600 g/L when the vacuum degree was 0.08 MPa,the distillation temperature was 85 ~C, and the distillation time was 60 rain.The methanol and the residual caustic soda solution can be thereby separated and recov- ered as required.