The Study On Green Preparation Process Of N-Acetyl-L-Cysteine

In recent years,the domestic and international market demand for N-acetyl-Lcysteine has been expanding rapidly,and a large amount of N-acetyl-L-cysteine ingredients is needed globally to manufacture expectorants and compound amino acid injections every year.However,the present synthesis methods of N-acetyl-L-cysteine have some problems,such as difficult product separation,low product quality and serious pollution.Therefore,we developed a new electrochemical synthesis and electrodialysis process to produce high quality N-acetyl-L-cysteine.The research work of this paper are as follows:1.By studying the LSV of the lead electrode,silver electrode and carbon electrode in the presence or without of N,N'-diacetyl-L-cystine solutions,it was found that all three electrodes had electrochemical responses to the disulfide compounds.2.The influence of different electrolysis conditions on the electrochemical synthesis of N-acetyl-L-cysteine was studied.Through the orthogonal experiment,the influence of cathode material,current density and DiNAC concentration was emphatically investigated.The conditions of electroreduction synthesis were optimized.3.In the process of electrochemical synthesis of N-acetyl-L-cysteine,electrodialysis was used,so as to realize the desalination and recycling of the mother liquor,and reduce the discharge of the three wastes to the greatest extent.4.The synthesis process of N-acetyl-L-cysteine from L-cystine was designed and developed,and we completed the design of N-acetyl-L-cysteine industrial demonstration plant with annual output of 30 tons.And the economic and technological evaluation is also carried out.