Ammonium nitrate and xylylenediamine co-production method and heat exchange network

Abstract

The invention provides an ammonium nitrate and xylylenediamine co-production method, which comprises the following steps of: 1, reacting natural gas, air and water to synthesize liquid ammonia and obtain hydrogen; 2, reacting the liquid ammonia in the step 1 with xylene and air to generate reaction outlet gas containing dicyanobenzene, cooling the reaction outlet gas, and contacting with a cold medium for trapping, obtaining a liquid phase and reaction tail gas, rectifying the liquid phase, and obtaining a dicyanobenzene refined product; 3, reacting the hydrogen in the step 1 with the dicyanobenzene refined product in the step 2 to obtain xylylenediamine, and then rectifying the xylylenediamine to obtain a xylylenediamine refined product; 4, reacting the liquid ammonia in the step 1 with oxygen and then reacting with water to generate nitric acid, reacting the nitric acid with the reaction tail gas in the step 2, obtaining an ammonium nitrate solution, concentrating and granulating the ammonium nitrate solution, and obtaining an ammonium nitrate product. According to the method, the ammonia-containing waste gas in the xylylenediamine production process can be recycled, meanwhile, a heat exchange network is designed, heat of all devices is reasonably matched, and energy is remarkably saved.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a co-production method of ammonium nitrate and xylylenediamine and a heat exchange network. Background technique [0002] The production of xylylenediamine has the following problems: [0003] 1. Excess ammonia problem: [0004] Xylylenediamine has two methylamine groups (-CH2NH2), which are generally produced by the reaction of methyl (-CH3) with ammonia and oxygen to form a cyano group (-CN), which is then hydrogenated, so xylylenediamine Amine belongs to the ammonia industry chain. And the reaction efficiency of methyl group to cyano group is very low, for methyl group reacts completely as far as possible, ammonia will be greatly excessive. Theoretically, the molar ratio of xylene and ammonia reaction only needs to be 1:2, but it is actually known to reach 1:4-10. In addition, the theoretical molar ratio of xylene and oxygen reaction is 1:3, and the s...

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Problems solved by technology

[0007] 2. Dicyanobenzene capture problem

Because the proportion of nitrogen and oxygen in the reaction outlet gas is large, the partial pressure is high, and the solvent with a low boiling point will volatilize and enter the reaction tail gas after contacting it, which is economically unacceptable, and the solvent in the tail gas is difficult to handle.

If the boiling point of the solvent is too high, it will be too close to dicyanobenzene, which will make separation difficult and consume a lot of energy.

[0009] 3. Comprehensive utilization of energy

Another example is the refining and rectifying process of dicyanobenzene. Although the heat required for gasification of dicyanobenzene is similar to the heat released by condensation, the heat required temperature is higher than the exothermic temperature, and the heat cannot be matched.

There is also the ammonia oxidation reaction, the temperature of the reactor and the reaction product gas is very high, which contains high-grade heat, and the gasification and preheating of the reaction principle only need very low-temperature heat. If it is forced to match, it is also a waste of energy

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