Method for preparing dichloropropanol by glycerol

Abstract

A method of preparing for dichloropropanol from glycerol is that the glycerol and catalyst are added into a spraying type reactor; a liquid circulating pump is used to pump the glycerol and the catalyst our from the spraying type reactor, then the glycerol and the catalyst are sent into the spraying type reactor from the top of the spraying type reactor by the manner of spraying; HCl gas which is absorbed from the lateral part of the spraying type reactor is mixed completely and react with the materials of the glycerol and the catalyst inside the spraying type reactor; at the same time the negative pressure produced by spraying brings a resultant inside the spraying type reactor in the form of an azeotropic matter of water, the dichloropropanol and the HCl; the water and the dichloropropanol in the azeotropic matter are condensed down by a condenser, and the unreacted HCl gas and the complementary HCl gas are sent into the spraying type reactor together for cyclic reaction. The invention has the advantages of the improvement of the reaction velocity and high glycerol transformation rate.

Description

technical field [0001] The invention belongs to a method for preparing dichloropropanol, in particular to a method for preparing dichloropropanol from glycerin. Background technique [0002] The main method of producing dichloropropanol at present is the propylene high-temperature chlorination method developed by U.S. Shell Company in 1948. The reaction principle is as follows: [0003] CH 2 =CH-CH 3 +Cl 2 →CH 2 =CH-CH 2 Cl+HCl [0004] CH 2 =CH-CH 2 Cl+Cl 2 +H 2 O→CH 2 Cl-CHOH-CH 2 Cl+CH 2 Cl-CHCl-CH 2 Oh [0005] The method is characterized by flexible production process, mature process, stable operation, and the production of various organic intermediates, but has disadvantages such as low conversion rate, many by-products, high energy consumption, serious equipment corrosion, and many waste water and waste residues. [0006] Another less-applied process is the propylene acetate method, and the reaction principle is as follows: [0007] [0008] [0...

AI Technical Summary

Problems solved by technology

The gas-liquid reactants flow in reverse, the utilization rate of HCl is improved, and the water in the reaction system is taken away by the reaction gas itself, and the non-volatile catalyst is preferred, the catalyst consumption is small, but the process energy consumption is still high and the equipment utilization rate is low

[0016] In short, the existing technology reacts in traditional reactors such as bubbling tanks or stirred tanks. The form of the reactor determines that the mass transfer efficiency is low and the reaction rate is low; the utilization rate of HCl is low; Large investment and high energy consumption

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