A heterogeneous continuous acid hydrolysis device and process for producing glyphosate by glycine method

Abstract

The invention provides a heterogeneous continuous acid hydrolysis process and device for producing glyphosate by a glycine method. The specific performance is that a horizontal horizontal heterogeneous reactor is used for acidolysis reaction, and the synthetic liquid is atomized and sprayed into the reactor, and the fresh hydrogen chloride gas and circulating gas passed into the reactor are in a fluidized state in the reactor. A heterogeneous acidolysis reaction occurs on the surface of the glyphosate seed crystal to directly produce glyphosate powder, and the reaction temperature is controlled by controlling the condensation and recirculation of the mixed cycle gas to evaporate the reactor. Compared with the traditional process, its advantage is that it does not introduce any aqueous solution into the acid hydrolysis system, and directly avoids the production of glyphosate mother liquor wastewater and methanol wastewater in the acid hydrolysis process, which not only reduces the environmental protection treatment cost of glyphosate, but also reduces various Loss and consumption, while also increasing the output of methyl chloride, a by-product of great economic value, the environmental protection and economic benefits are very significant.

Description

technical field [0001] The invention belongs to the technical field of glyphosate production by a glycine method, and specifically relates to a technique and a device for applying the heterogeneous continuous acid hydrolysis method to the acid hydrolysis process in the glyphosate synthesis process. Background technique [0002] Glyphosate, also known as Roundup, is a non-selective systemic conduction herbicide. At present, there are two mainstream production methods of glyphosate, one is the production method using iminodiacetic acid (IDA) as the raw material, and the other is the production method using glycine and alkyl phosphite as the raw material. In my country, the synthesis of glyphosate by the glycine-alkyl ester method occupies a dominant position. The specific process is as follows: using triethylamine as a catalyst, paraformaldehyde is depolymerized in the solvent methanol to form hemiacetal, and after further reaction with glycine Esterification with dimethyl pho...

AI Technical Summary

Problems solved by technology

First of all, since the acid hydrolysis process is carried out at a lower pH value, in the subsequent crystallization process, it is necessary to put in an equivalent amount of lye to neutralize excess hydrochloric acid to ensure that glyphosate is precipitated from the solution as much as possible, resulting in the final production of The glyphosate mother liquid salt content is relatively high, and it also contains dissolved glyphosate, glyphosate, triethylamine salt and other biologically toxic organic substances, which makes it impossible to directly carry out biochemical treatment, and requires advanced oxidation, evaporation crystallization, High-cost and complicated treatment methods such as rectification and incineration

Therefore, how to treat the glyphosate mother liquor wastewater with large discharge, high salt content, high biotoxic organic matter content and high organic nitrogen content at low cost has become the environmental protection technology bottleneck of glycine production glyphosate enterprises

Secondly, due to the introduction of a large amount of water, a large amount of wastewater with high methanol content will be produced in the subsequent desolventization process, which requires methanol recovery. The energy consumption in the process of separation, incineration, etc. is very high

Third, due to the large amount of process wastewater such as methanol wastewater and mother liquor wastewater generated during the synthesis process, the loss of material and product dissolution is large

Fourth, due to the introduction of water, the hydrolysis reaction between water and the methoxy group of the organic phosphine intermediate, about half of the methoxy group is converted into methanol, and only about half of the methoxy group reacts with hydrogen chloride and is converted into Chloromethane, and methyl chloride can be used as an important chemical raw material for organosilicon and other industries. Methanol is only a common organic solvent, so the atomic economic benefits of the methoxy group are greatly reduced

Fifth, due to the need for lye neutralization, the sodium ion content in the product is relatively high. When it is necessary to produce low-sodium high-purity glyphosate products, the only way to wash the product repeatedly with high-purity soft water is to increase the dissolution loss. large, resulting in a decrease in the total yield of glyphosate, an increase in water consumption, and an increase in the amount of wastewater

At the same time, due to the introduction of a large amount of chloride ions, the corrosion of high-concentration chloride ions needs to be considered in the follow-up treatment device, and the use of dual-phase steel, titanium, etc. material, even special alloy equipment such as zirconium material, the equipment investment of the whole system is very huge

In addition, the traditional acidolysis process adopts the batch process, which has low utilization rate of the reactor, serious back-mixing, and many side reaction products. The output of a single batch is limited by the size of the reactor, and it is difficult to scale up on a large scale.

[0009] In summary, in the acid hydrolysis process of glyphosate synthesized by the traditional glycine method, the addition of hydrochloric acid brings environmental problems such as glyphosate mother liquor and methanol wastewater, and also increases the material consumption and energy consumption of the production process.

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