The Optimization Of Process Parameters In The Production Of Analgin

In this study, it was found that there were still many problems in the process of producing analgin,though it has been be put into production for more than fifty years in our country.Lots of work has been done to find out the source of the problem. We found there was a lot of non-ferrous by-products and colloid in the process of producing analgin,especially the front steps.,which affect the product quality and yield seriously. This article focus on the optimization of chemical reaction process conditions. Chemical reaction mechanism and operating conditions in process of producing AT and Faa were conducted as the main research content.It was found that the pyrazolone conversion rate reached a maximum of 98.62% when molar ratio of dimethyl sulfate and pyrazolones was 1.1:1 and reacted at 160 ℃ under the presence of reducing agent P. In alkali-treated reaction, all materials were added at the same time. A higher yield of 98.34% can be obtained when molar ratio of sodium hydroxide and reactant was 2.3:1 and reacted for 2 hours at 105 ℃ raised from initial temperature of 60 ℃.In Faa stage, process parameters of nitrosation reaction and hydrolysis reaction are optimized.It was found that Faa yield can reach up to 84.71% when materials were added at the same time and reacted at 5 ℃.The pH of reaction system was approximately 2 to 3 and stirring speed was kept 360 rotations per minutes.The optimal reaction conditions for the hydrolysis reaction could be obtained when feed temperature was 60 ℃ with the sulfuric acid dilution ratio of 1:3. The average particle size of the solution could be reduced from 4400 nm to 1000 nm by optimizing the hydrolysis reaction conditions. By means of the treatment above, we successfully eliminated the colloid, got rid of the chloroform extraction process and simplified the process operations.The new technology of producing AT and Faa has been adopted in manufacturing enterprises,and the quality of analginum were improved significantly. All products are up to the enterprise Export Standard.