Experimental Study On Dehydration Of Depolymerization Liquid During Production Of Glyphosate

Glyphosate was promoted globally as a broad-spectrum herbicide in the 20th century,and the market grew rapidly due to its good herbicidal properties.Among the many synthetic methods of glyphosate,the glycine process route is more commonly used.Studies have shown that in the glycine process route,removing a trace amount of water in the depolymerization solution can increase the yield of glyphosate,but the depolymerization solution contains a large amount of water.Removal of trace amounts of water from methanol and methanol solutions is currently a problem in the industry.The adsorption method is the most promising for industrialized production.However,the existing commercial dehydrating agents will produce co-adsorption due to the small difference between methanol and hydrodynamic diameters,making it difficult to achieve separation.In order to solve this industry problem,we first cooperated with Dongfang Guansen Company to modify and process different combinations of formulas using diatomaceous earth as raw materials to produce 4 modified dehydrating agents,and to study the effects of four dehydrating agents on glyphosate Dehydration of the depolymerization solution.First,static adsorption experiments and dynamic adsorption experiments were performed on the four modified dehydrating agents to determine the main process parameters;then the two dehydrating agents with better effects were analyzed by SEM and BET;finally,the corresponding adsorption was designed according to the actual production requirements of the manufacturer.And numerical simulation of the packing form of the dehydrating agent in the adsorption tower.The main work results are as follows:（1）Static adsorption experiments show that among the four dehydrating agents,GX-3 has the best effect on removing trace water in the glyphosate depolymerization solution.GX-3 is used for subsequent dynamic adsorption experiments.（2）The dynamic adsorption experiment shows that the best residence time of GX3 in the adsorption column is 2 hours,and the regeneration period is T=8h.After working for 8 hours,the maximum processing capacity can reach about 5 times the loading capacity.The average water content of the depolymerization solution after mixing is 0.051%,which meets the production requirements.（3）According to the actual production needs of the manufacturer,design the adsorption tower to take the empty tower flow rate v₀=0.0005m/s,the depolymerization liquid flow rate W=2.5t/h,then the cycle production capacity is 20t/tower,the total tower height H=8.3m,The diameter D=1.5m,the filling height of the dehydrating agent is 5.5m,and the dehydrating agent is in the form of integral filling.In summary,the use of GX-3 as a depolymerization liquid dehydrating agent for industrial applications has good adsorption performance and strong reproducibility,which can meet the needs of industrial production and initially solve the industry problem of low-carbon alcohol dehydration.