China is a big agricultural country, as well as a big pesticide production and demand country. Herbicides, as an important pesticide product in agricultural production and labor reduction, have become the main product demand in the field of pesticide subdivision. At present, the annual output of herbicides in the world is 800-900,000 tons, accounting for about 50% of the total chemical pesticides, among which glyphosate, paraquat and glyphosate are the main water-soluble herbicides. At present, with the withdrawal of paraquat and the serious resistance of glyphosate to single agent, glyphosate, as one of the excellent alternatives to glyphosate, has become the second largest tolerant herbicide of genetically modified crops in the world. The stable start-up enterprises of glyphosate in China are maintained at about 5, and the theoretical value of market capacity is between 1.2 and 15,000 tons. The actual capacity may be reduced by about 20% due to the restriction of environmental protection verification and the influence of equipment maintenance.
At present, the synthetic routes of glyphosate are mainly divided into Strecher route and Hoechst route. The "three wastes" of Strecher route are seriously discharged, the pressure of environmental protection is great, and the release of production capacity of some enterprises is limited. The "three wastes" of Hoechst route have a strong cost advantage, but domestic enterprises have not fully grasped it. At present, China's glyphosate enterprises basically adopt Strecher route, usually using the following processes: format reaction, addition reaction, hydrochloric acid acidification, ammonia ammoniation, centrifugation, alcohol washing, distillation, drying into powder. Because of the long route, high solvent consumption and unstable product quality, the whole process increases the cost of solvent recovery and environmental protection pressure. Therefore, the improvement of production technology of glyphosate depends on the application of other high-tech.
Membrane Separation Technology
Membrane integration technology is applied to clean production of glyphosate. Without changing the quality of 95% glyphosate raw powder, on the one hand, the product quality of 95% glyphosate can be stabilized, and the industrial continuous production operation can be realized. On the other hand, compared with the traditional process, the yield of glyphosate production can be increased by more than 15%. It can realize cleaner production in the separation and purification section of glyphosate without waste discharge and improve the quality of by-product ammonium salt.
Membrane integration technology applied in purification, separation and concentration of glyphosate production process has become a new green environmental protection and energy saving technology for the production of herbicide glyphosate varieties, which can provide sustained power for enterprises to reduce costs and increase efficiency.