Process for hydrolyzing lime nitrogen at one step

Abstract

The invention provides a process for hydrolyzing lime nitrogen at one step. The process includes adding the lime nitrogen into a hydrolysis reaction kettle and simultaneously continuously filling the hydrolysis reaction kettle with mixed gas with nitrogen and carbon dioxide; dripping water and methanol liquor into the hydrolysis reaction kettle; continuously stirring the lime nitrogen, the water and the methanol liquor. The mass ratio of the water to the methanol liquor is 1-2:1. The concentration of the methanol liquor is 5-15%. An internal PH (potential of hydrogen) value of the hydrolysis reaction kettle is 6.5-6.8 when the water and the methanol liquor are dripped into the hydrolysis reaction kettle. The process has the advantages that the lime nitrogen can be hydrolyzed at one step by the aid of technologies for producing cyanamide, the dripping quantities of methyl cyanamido formate can be reduced in methyl cyanamido formate dripping procedures owing to high-quality liquid cyanamide, accordingly, consumption can be reduced, and a foundation can be laid for continuous production; the efficiency of hydrolysis kettles can be greatly improved, working hours of filter presses can be reduced, consumption of methanol can be decreased, the feasibility of hydrocyanic amine base liquor continuous production can be improved, the consumption of the methanol can be decreased by 5% at least, and the efficiency of esterification kettles can be improved by 1.5 times.

Description

technical field [0001] The invention relates to the field of carbendazim production, in particular to a process for one-time hydrolysis of lime nitrogen. Background technique [0002] Carbendazim, chemical name N-(2-benzoimidazolyl)-methyl carbamate, is an odorless powder, sublimates at 215-217°C, melts at 290°C, decomposes at 306°C, insoluble in water , Slightly soluble in acetone, chloroform and other organic solvents, soluble in inorganic acids and acetic acid, and form corresponding salts, chemically stable. Its main dosage form is 25% and 50% wettable powder, which is a broad-spectrum fungicide, which can prevent and control the diseases caused by fungi (such as Deuteromycetes, polyascomycetes) of various crops, and can be used for foliar spraying , seed treatment and soil treatment, etc. [0003] Methyl cyanamide is a pesticide and an intermediate of fine chemicals. It is colorless or has a little light blue aqueous solution. It is weakly alkaline and has an odor. It...

AI Technical Summary

Problems solved by technology

[0005] Existing technology adopts lime nitrogen method to produce when producing cyanamide, because lime nitrogen decomposes and is alkaline in water, so when producing cyanamide, easily produce by-products, cause the purity of cyanamide is not high, affect cyanamide formic acid The conversion rate of methyl ester affects the purity and conversion rate of carbendazim