Method for improving recovery rate of nitric acid in glucurolactone production

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