Nitric acid production technology with double-pressurized method

A production process, double pressurization technology, applied in the direction of nitric acid, sustainable manufacturing/processing, chemical industry, etc., can solve the problems of not reducing the NOx content in the tail gas, low output, high production cost, etc., and achieve heat recovery The effect of good utilization, low NOx content, and lower absorption temperature

Inactive Publication Date: 2016-03-02
蒋小华
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Application No. 201110323653.X discloses a high-concentration dilute nitric acid production process. The process is to combine dilute nitric acid and concentrated nitric acid to produce dilute nitric acid by means of a double pressurized dilute nitric acid device. Using super azeotropic nitric acid distillation and rectification technology to produce concentrated nitric acid with a mass concentration greater than 98%, the production cost of this process is high, the output is low, and the content of NOx in the tail gas is not well reduced.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] (1) Mixing of raw materials: liquid ammonia is pressurized to 0.52MPa by the ammonia evaporator, then heated to 100°C by the heater, enters the ammonia filter, removes oil and other impurities, and adjusts the system and air through the ammonia air ratio Mixing, the air used for mixing should enter the air filter and air compressor in advance, pressurize to 0.45MPa, and control the temperature at 236°C;

[0020] (2) Ammoxidation reaction process: Ammonia-air mixed gas is evenly distributed on the platinum grid through the distributor on the top of the ammonia oxidation furnace, and the oxidation reaction of ammonia is carried out. The reaction temperature is controlled at 860°C and the pressure is controlled at 0.45MPa;

[0021] (3) Heat recovery and cooling process: the NOx-containing gas after the above reaction passes through the steam superheater, waste heat boiler, high-temperature gas-gas heat exchanger, and economizer to recover heat, and then passes through the l...

Embodiment 2

[0025] Example 2: The rest is the same as in Example 1, the difference is that the ammonia oxygen reaction temperature in step (2) is controlled at 880°C, the bleaching tower top pressure in step (5) is -25KPa, and the temperature is 43°C, and the step ( 6) The medium tail gas is heated to 365°C.

[0026]

Example 1 Example 2 Example 3 Total Ammonia Utilization 93.2% 96.5% 91.3% NOx removal rate in bleaching tower 97.2% 98.1% 94.5% NOx content in exhaust gas 20ppm 15ppm 25ppm

[0027] Through the above three examples, it can be seen from the three sets of data in the above table that the ammonia oxygen reaction temperature is controlled at 880°C, the top pressure of the bleaching tower is controlled at -25KPa, the temperature is 43°C, and the tail gas is gradually heated to 365°C before entering the tail gas expander. At this time, the total utilization rate of nitrogen and the NOx removal rate in the bleaching tower are the highe...

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PUM

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Abstract

The invention discloses a nitric acid production technology with a double-pressurized method. The technology includes the steps of: (1) mixing of raw materials; (2) operation of an ammoxidation reaction; (3) thermal recovery and cooling; (4) absorption; (5) bleaching; and (6) treatment of tail gas. The production technology is reasonable and simple, and has high ammonia utilization rate, low platinum consumption, high absorptivity, high concentration of finished acid, and low content of NOx in the tail gas. Moreover, the production technology avoids wasting of energy resources, is suitable for promotion in various nitric acid manufactures, and has good thermal recovery so that the steam is more than self-sufficient.

Description

technical field [0001] The invention relates to a production process of chemicals, in particular to a production process of nitric acid. Background technique [0002] Nitric acid has a wide range of uses and is often used to produce a series of nitrate nitrogen fertilizers. Because nitric acid is both oxidizing and acidic, nitric acid is also used to refine metals. The nitric acid production process is generally divided into five types according to the pressure, namely the normal pressure method, the full medium pressure method, the comprehensive method, the full high pressure method and the double pressurized method. The constant pressure method and the comprehensive method are early nitric acid production processes, which have small production capacity, high consumption, heavy pollution, and low acid concentration, and have been eliminated. The full medium pressure method and the full high pressure method carry out oxidation and absorption under pressure, the production i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B21/38
CPCY02P20/10Y02P20/129
Inventor 蒋小华
Owner 蒋小华
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