中文摘要：
随着社会的发展,传统化学制造业存在的高消耗、低产出、高排放等问题对人类的生存环境产生不可逆性的破坏,使各国的经济和自然环境遭到了前所未有的挑战,绿色化学概念成为化工行业发展的新方向。有机电化学以电子为试剂,在常温、常压和低电压下即可高选择性地获得目标产物,是绿色化学重要的发展方向。电化学法合DL-高半胱氨酸硫内酯盐酸盐相比于传统化学法,具有反应过程温和、操作简单、反应环保、转化率高等优势。本文以DL-高半胱氨酸硫内酯盐酸盐的电化学合成工艺为研究对象,通过对电解相关材料、设备及工艺条件的优化,为该技术的工业化应用奠定基础,为电化学合成技术在精细化工领域的应用提供示范。主要研究内容及结果如下:以DL-高胱氨酸为原料,盐酸溶液为溶剂,在板框电解槽中以改性石墨电极为阴、阳极进行合成DL-高半胱氨酸的研究。考察了阴极电流密度、电解温度、DL-高胱氨酸浓度、电解液流速和阴极液盐酸浓度等工艺因素对电解过程的影响,结果表明:随着阴极电流密度和电解液流速的升高,电流效率呈现先升高后降低的变化,电流效率随着电解液中DL-高胱氨酸浓度的升高而增大,但随DL-高胱氨酸与盐酸物质的量之比的升高而下降。此外,还发现在所研究的温度范围内,DL-高胱氨酸电解效率与温度基本无关。基于上述研究结果,获得最优反应条件为:DL-高胱氨酸浓度为1.5 mol/L、盐酸与DL-高胱氨酸物质的量比为1∶3、电流密度为20 m A/cm~2、流速为60 m L/min。电解结束后,电解液通过蒸发浓缩、低温结晶、过滤、提纯精制和真空干燥等步骤即可获得目标产物。为了对电解工艺进行优化,基于高效液相色谱建立了相应的分析测试方法,对原料、中间产物和目标产物进行检测和定量分析,具体如下:流动相为V(磷酸盐缓冲溶液):V(乙腈)=85∶15,紫外检测器波长为220 nm,柱温为28°C,流动相流速为1 m L/min,进样量为20μL。同时以采用核磁及红外对目标产物进行了表征,以进一步验证目标产物的结构。在上述小试基础上,考察了DL-高半胱氨酸硫内酯盐酸盐电解合成技术的放大效应。基于放大试验结果设计了年产1000 t DL-高半胱氨酸硫内酯盐酸盐的电化学反应器,并进一步对年产1000 t DL-高半胱氨酸硫内酯盐酸盐工业生产项目进行了物料衡算和技术经济分析,为该技术的工业化应用奠定基础。
英文摘要：
With the development of society,the problems of high consumption,low output,and high emissions in the traditional chemical manufacturing industry have irreversibly damaged the living environment of human beings,which has caused unprecedented challenges to the economy and natural environment of various countries.The concept of green chemistry become a new direction for the development of the chemical industry.Organic electrochemistry uses electrons as reagents to obtain target products with high selectivity under normal temperature,normal pressure and low voltage,which is an important development direction of green chemistry.Electrochemical synthesis technology has great application potential in energy saving and emission reduction of high value-added fine chemicals production process.This article takes the electrochemical synthesis process of DL-homocysteine thiolactone hydrochloride as the research object.Through the optimization of electrolysis-related materials,equipment and process conditions,lay the foundation for industrial application,provide a demonstration for the application of electrochemical synthesis technology in the field of fine chemicals.The main research contents and results are as follows:DL-homocystine was used as raw material,hydrochloric acid solution was used as solvent,and modified graphite electrode was used as cathode and anode in plate-frame electrolysis cell to study DL-homocysteine.The effects of five process factors such as cathode current density,electrolysis temperature,DL-homocystine concentration,electrolyte flow rate and catholyte hydrochloric acid concentration on the electrolysis process were investigated,the results show that as the cathode current density and electrolyte flow rate increase,current efficiency increases first and then decreases.The current efficiency increases as the concentration of DL-homocystine in the electrolyte increases,but it decreased with the increase of the ratio of DL-homocystine to hydrochloric acid.In addition,it was found that within the studied temperature range,the DL-homocystine electrolysis efficiency was basically independent of temperature.Based on the above research results,the optimal reaction conditions were obtained:the concentration of DL-homocystine was 1.5 mol/L,the ratio of hydrochloric acid to DL-homocystine substance was 1:3,and the current density was 20 m A/cm~2,the flow rate is 60 m L/min.After the electrolysis process,the target product can be obtained through the steps of evaporation concentration,low temperature crystallization,filtration,purification and purification,and vacuum drying.In order to optimize the electrolysis process,the corresponding analytical test method was established based on high performance liquid chromatography to detect and quantitatively analyze the raw materials,intermediate products and target products,as follows:the volume ratio of phosphate buffer solution to acetonitrile in the mobile phase was 85:15,the UV detector wavelength was 220 nm,the column temperature was 28°C,the mobile phase flow rate was 1 m L/min,and the injection volume was 20μL.At the same time,the target product was characterized by nuclear magnetic and infrared to further verify the structure of the target product.Based on the above research,the thesis carried out the scale-up experiment of DL-homocysteine thiolactone hydrochloride,and an electrochemical reactor with an annual output of 1000 t DL-homocysteine thiolactone hydrochloride was designed based on the scaled-up test results.Further material balance and economic analysis were carried out on the industrial production project with an annual output of 1000 t DL-homocysteine thiolactone hydrochloride,lay the foundation for industrial application.
