Method for improving recovery rate of nitric acid in glucurolactone production

Abstract

The invention relates to a method for improving the recovery rate of nitric acid in glucurolactone production. The method comprises the following steps: firstly, scrubbing nitric oxide gas generated by hydrolysis reaction during production of glucurolactone by a circulating scrubber tower, and condensing high-temperature water vapor in nitric oxide gas generated by hydrolysis reaction in circulating scrubbing water; secondly, mixing nitric oxide gas generated by hydrolysis reaction after circulating scrubbing with nitric oxide gas generated by oxidation reaction and then introducing air in the mixture; thirdly, inputting NO2 into 1-10-level cooling absorption towers, and controlling the spraying temperature of the circulating dilute nitric acid in the tower to be at 5-20 DEG C, wherein the NO2 and the dilute nitric acid are subjected to contact absorption to improve the concentration of the dilute nitric acid, when the concentration of the dilute nitric acid reaches 55-70%, mixing the dilute nitric acid with concentrated nitric acid to prepare the nitric acid with concentration of 72-73% for glucurolactone production; and fourthly, supplementing nitric-acid-containing steam condensate produced during circulating scrubbing of the nitric oxide gas generated by hydrolysis reaction into an acid absorption tower as a basic solution for dilute nitric acid absorption for cyclic utilization. The method can be used for reducing the total quantity of the nitric oxide gas entering the alkali absorption system, reducing the follow-up alkali absorption and consumption and reducing the cost for follow-up nitric oxide gas treatment.

Description

[0001] technical field [0002] [0003] The invention relates to the fields of material recovery, recycling and "three wastes" treatment in pharmaceutical synthesis production, in particular to a recovery and treatment method for nitrogen oxide gas decomposed by nitric acid in the production process of glucuronolactone. [0004] Background technique [0005] [0006] The industrialized production of glucuronolactone in my country is made of starch as the main raw material, nitric acid as the oxidant, and is produced through three steps of oxidation, hydrolysis, and esterification. A large amount of nitrogen oxide gas is produced during the oxidation reaction and hydrolysis reaction. In order to reduce the The production of glucuronolactone consumes nitric acid and solves the problem of nitrogen oxide gas pollution. The process adopts water circulation absorption to prepare dilute nitric acid, and alkali circulation absorption to reduce pollution. There are the followin...

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Problems solved by technology

[0009] The purpose of the present invention is to improve the nitric oxide gas absorption treatment method for the defects in the nitric oxide gas absorption treatment in the production process of glucuronolactone, use the nitric oxide gas as raw material to produce dilute nitric acid and prepare sodium nitrite, and solve the problem of nitric oxide gas To solve the pollution problem and provide a method to improve the recovery rate of nitric acid in the production of glucuronolactone

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