Joint production method and production device of dilute nitric acid and concentrated nitric acid

Abstract

A joint production method of dilute nitric acid and concentrated nitric acid comprises the following steps: superazeotropic nitric acid with the mass concentration greater than 68.4% is produced by a dual-pressure dilute nitric acid production device, then concentrated nitric acid with the mass concentration greater than 98% is produced by a superazeotropic nitric acid distillation and rectification technology, and dilute nitric acid with the mass concentration greater than 60% is produced at the same time by matching. According to the production method, ammonia and air are employed to produce concentrated nitric acid, ammonia is oxidized at medium pressure, nitrogen oxides are absorbed at high pressure, the content of NOx in the exhaust gas after absorption is less than and equal to 30ppm after ammonia reduction reaction, the problem of environmental pollution is solved, and dilute nitric acid and concentrated nitric acid in any proportion and any concentration can be simultaneously produced without pure oxygen and any other dehydrating agent.

Description

technical field [0001] The invention belongs to the technical field of nitric acid production, and relates to a method for jointly producing dilute nitric acid and concentrated nitric acid, and a production device suitable for the method. Background technique [0002] Nitric acid has the remarkable characteristics of a binary azeotropic mixture, and its highest boiling point is 121.9°C, and the corresponding concentration is 68.4%. Therefore, nitric acid can be divided into dilute nitric acid and concentrated nitric acid. Products with a concentration of less than 68.4% are dilute nitric acid, and products with a concentration greater than 98% are concentrated nitric acid. Correspondingly, there are dilute nitric acid production methods, concentrated nitric acid production methods and their respective production devices. Due to the characteristic of constant boiling point of nitric acid, concentrated nitric acid cannot be obtained directly from dilute nitric acid by distilla...

AI Technical Summary

Problems solved by technology

Although there is also a method of direct nitration method of direct synthesis by adding oxygen, most people in the industry are unwilling to use this method because it needs to add pure oxygen and react under high pressure, which brings difficulties to the manufacture, maintenance, use, control and safety of the equipment. production method

However, choosing to build a set of dilute nitric acid plant and then build a set of concentrated nitric acid plant can meet the needs of products and safe and stable production, but it will undoubtedly increase investment, increase construction area, increase wastewater discharge, and increase operating and maintenance personnel. production running cost

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