Method for co-production of aramid fiber scale m-phenylenediamine and resorcinol

Abstract

The invention discloses a method for co-production of aramid fiber scale m-phenylenediamine and resorcinol. The method includes: cooling a m-phenylenediamine aqueous solution in a crystallization pot, precipitating part of m-phenylenediamine and trace o-phenylenediamine and p-phenylenediamine crystals, conducting filtration, and preparing aramid fiber scale m-phenylenediamine from a filter cake; adding sulfuric acid into a filtrated stock diluted by water, letting the filtrated stock react with sulfuric acid to generate m-phenylenediamine sulfate, continuously sending the m-phenylenediamine sulfate to a heater to undergo heating and sending it into a hydrolysis reaction kettle, subjecting the hydrolysate from the hydrolysis reaction kettle to flash evaporation to recover part of water for preparing the m-phenylenediamine aqueous solution, and adding ammonia water into the hydrolysate undergoing flash evaporation to perform neutralization; extracting the neutralized hydrolysate with butyl acetate, recovering butyl acetate from the extracted liquid in a butyl acetate recovery tower, and distilling the butyl acetate recovered rough resorcinol, thus obtaining the finished product resorcinol. According to the invention, the crystallization mother liquor has no need for concentration, the crystallization process is simple, and the co-production of the aramid fiber scale m-phenylenediamine and resorcinol is free of the coking problem in a crystallization mother liquor concentration process, and secondary pollution can be avoided.

Description

technical field [0001] The invention belongs to the technical field of chemical product production technology, and more specifically relates to a co-production method of aramid grade m-phenylenediamine and resorcinol. Background technique [0002] Aramid 1313 is a polyamide fiber. It is used to make anti-radiation clothing, aerospace clothing, and tire window strings for special requirements. It is also used in the manufacture of high-temperature resistant clothing, honeycomb parts, high-temperature line pipes, aircraft fuel tanks, firewalls, reverse osmosis membranes or hollow fibers, etc. [0003] Aramid 1313 is a soft, white, slender, fluffy and lustrous fiber. Its appearance is no different from that of ordinary chemical fibers, but it has all the advantages in one, and has extraordinary special functions: (1) Durable thermal stability, can be used in Long-term use at a high temperature of 220°C without aging, its electrical and mechanical properties can be maintaine...

AI Technical Summary

Problems solved by technology

If the concentration of the mother liquor is too low, it is not easy to obtain high-quality m-phenylenediamine; if the concentration of the mother liquor is too high, it is easy to obtain high-quality m-phenylenediamine, but the utilization rate of m-phenylenediamine is low

In order to improve the utilization rate of m-phenylenediamine and the purity of aramid-grade products, secondary or even tertiary crystallization is usually required. Repeated heating and cooling of the m-phenylenediamine solution is required during multiple crystallization processes, which consumes a lot of energy and is recovered in the mother liquor. The m-phenylenediamine needs to remove a large amount of solvent in the mother liquor, and it also needs to consume energy, and the energy consumption is high. At the same time, removing the solvent in the mother liquor will produce tar in the tower kettle, resulting in the loss of m-phenylenediamine

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