【作者】 陈宇；

【导师】 黄智贤；

【作者基本信息】 福州大学 ， 化学工程（专业学位）， 2022， 硕士

【摘要】 乳酸甲酯由于其水溶性好、挥发性低、无毒、易生物降解等优点,被广泛应用于香料、涂料及半导体等行业。近年来,随着电子行业的高速发展,高品质的超高纯乳酸甲酯需求量日益增加。传统的糖类转化法和甘油转化法存在经济效益差、产物选择性低等问题,而酯化法无需较高的反应温度,且转化率高、收率高,日益成为研究的热点。目前乳酸甲酯主要以硫酸为催化剂,采用釜式反应器-间歇精馏工艺生产,该工艺存在操作复杂、催化剂无法回收等问题。为此,本文以酸性阳离子交换树酯为催化剂,开发了乳酸甲酯固定床反应器-连续精馏新工艺,主要研究内容如下:（1）乳酸甲酯合成工艺研究。在填充有HND-8型强酸性阳离子交换树脂的固定床反应器中进行酯化实验,通过单因素分析实验考察停留时间、醇酸摩尔比、反应温度对酯化反应的影响;并通过正交实验及响应面分析,获得乳酸转化率与停留时间、反应温度以及醇酸摩尔比的二次多项式模型;借助Aspen Plus对不同醇酸摩尔比下酯化、中和及甲醇回收过程的年度总成本进行比较,确定乳酸甲酯酯化过程的较佳操作条件:醇酸摩尔比为8:1,停留时间为32.27 min,反应温度77.33°C,该条件下乳酸的转化率为93.01%。（2）乳酸甲酯提纯工艺研究。根据固定床反应器出口物料组成和各组分物性提出分离提纯工艺。采用间歇精馏实验得到满足超高纯化学品G1标准的乳酸甲酯产品,其平均纯度为99.965%,最高纯度可达到99.986%,金属离子浓度均小于100 ppb。利用Aspen Plus对乳酸甲酯提纯工艺进行稳态模拟,以TAC最小为目标进行提纯工艺的优化,并得到较佳的操作条件。该条件下,产品乳酸甲酯纯度≥99.9%,过程能耗为866.801 kw·t^-1。（3）年产一万吨超高纯乳酸甲酯工艺设计。在上述乳酸甲酯合成及提纯工艺研究的基础上,建立了酯化法合成乳酸甲酯的工艺流程,在物料衡算的基础上对主要设备进行选型计算,绘制PFD图以及PID图等图纸,完成工艺包的初步设计。更多还原

【Abstract】 Methyl lactate has broad application prospects in fragrance,coating and semiconductor industries due to its advantages of good water solubility,low volatility,non-toxicity,and easy biodegradation.In recent years,with the rapid development of electronic industry,the demand for high quality ultra-high purity methyl lactate is increasing day by day.The traditional sugar conversion method and glycerol conversion method have problems such as poor economic benefit and low product selectivity,while the esterification process,which does not require a higher reaction temperature and has obvious economic advantages,has received extensive attention.At present,methyl lactate is mainly produced by tank reactor and batch distillation with sulfuric acid as catalyst,but this process is essentially realized at the expense of complicated operation,unrecoverable catalyst.To this end,this paper developed a new process of methyl lactate fixed bed reactor and continuous distillation using acidic cation exchange resin as catalyst.The main research contents are as follows:（1）Study on the synthesis process of methyl lactate.The esterification experiment was carried out in a fixed bed reactor filled with HND-8 resin.The effects of residence time,molar ratio of alkyd to acid and reaction temperature on the esterification reaction were investigated by single factor analysis;the quadratic polynomial model of lactic acid conversion with residence time,reaction temperature and molar ratio of alkyd was obtained by orthogonal experiment and response surface analysis;calculate the operating costs of methanol esterification,neutralization and recovery under different alkyd molar ratios by Aspen Plus.The optimal operation conditions for the synthesis of methyl lactate in fixed-bed reactor were determined as follows:the alkyd molar ratio was 8:1,the residence time was 32.27 min,and the reaction temperature was 77.33°C,the conversion of lactic acid under these conditions was 93.01%.（2）Study on purification technology of methyl lactate.The separation and purification process were put forward according to the material composition at the outlet of fixed bed reactor and physical properties of each component.Batch distillation experiment was used to receive methyl lactate which met the G1 standard of ultra-high purity chemical.The average purity was99.965%,the highest purity was 99.986%.Furthermore,the concentration of metal ions was less than 100 ppb.The steady-state simulation of the purification process of methyl lactate was carried out by Aspen Plus,and the simulation and optimization of the purification process was carried out with the minimum TAC as the optimization objective,and the appropriate operating conditions were obtained.Under the optimized conditions,the purity of methyl lactate was equal to or greater than 99.9%,the process energy consumption is 866.801 kw·t^-1.（3）Process design for an annual output of 10,000 tons of ultra-high purity methyl lactate.On the basis of the above-mentioned research on the synthesis and purification of methyl lactate,the process flow for synthesizing methyl lactate by esterification method was established.Based on the material balance calculation,the main equipment was selected and calculated,the PFD diagram and PID diagram were drawn,and the preliminary design of the process package was completed.更多还原