Method for continuous production of n-butyl chloride

Abstract

The invention provides a method for continuously producing n-chlorobutane, which belongs to an organic synthesis process. The process consists of reactive distillation stage, an isobutanol recovery stage and a washing distillation stage. The process substitutes hydrogen chloride gas for 30 percent of hydrochloric acid, integrates a reaction stage with a separation stage, adopts an azeotropic water-shift technique, controls the unit consumption needed for producing one ton of 99.5 percent n-chlorobutane to be less than 0.86 ton of isobutanol, 1.8 tons of hydrogen chloride gas, 1.8 tons of steam, 60 kwh or electrical power and less than 0.001 ton of formed COD, reduces 80 percent of sewage discharged during the whole process, and reduces 80 percent of energy consumption. A product obtained by the method contains more than 99.5 percent (weight) of n-chlorobutane, less than 0.02 percent (weight) of isobutanol and less than 0.01 percent (weight) of dibutyl ether.

Description

technical field [0001] The invention belongs to an organic synthesis technique, and relates to a method for continuously producing n-butane chloride by using n-butanol and hydrogen chloride gas as raw materials. Background technique [0002] Chinese invention patent CN91105072.8 discloses "a method for producing n-chlorobutane", which uses n-butanol and hydrochloric acid as raw materials, does not add catalysts, and continuously produces n-chlorinated butane under normal pressure, n-butanol and concentration of 30-31% industrial hydrochloric acid is reacted in a reaction kettle with a temperature of 90-105°C under boiling, and the generated n-chlorobutane, water, part of unreacted n-butanol and a small amount of hydrochloric acid are distilled out together, and after condensation Enter the azeotropic distillation tower, control the temperature of the mixture in the azeotropic distillation tower to be 70-80°C, and the temperature at the top of the tower to be 68±1°C. The bot...

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Problems solved by technology

[0003] This process is composed of a reaction section, a separation section, a refining section, and a butanol recovery section. The one-way reaction rate of the reaction section is low, only about 20%, and there is a repeated heating process. The unit consumption of raw materials and energy consumption are relatively high, and the consumption per ton of product is positive 0.95 tons of butanol, 3 tons of hydrochloric acid, 7.6 tons of steam, and 200kwh of electricity, which do not meet the green production requirements of energy saving, emission reduction, and consumption reduction

In addition, the raw material hydrochloric acid used in this process contains about 70% water, which needs to be raised from normal temperature to reaction temperature in the production process, and there will be corresponding consumption of steam and electricity in other processes. About 3.5 tons of steam is wasted per ton of product, about 1.5 tons of steam is wasted per ton of product in the distillation process, about 0.8 tons of steam is wasted per ton of product in the recovery process of n-butanol, and about 140 kwh / ton of electricity is wasted in cooling water circulation and material circulation. ton of product, a large amount of organic matter (about 45%) such as n-butanol dissolves wherein in its water separation process, there is a certain amount of process loss when reclaiming n-butanol; There is a large amount of acid (more than 20%) that cannot recover the reaction system, and the excessive consumption reaches about 0.72 tons of hydrogen chloride gas per ton of product waste, and 2.5 tons of slaked lime is needed to neutralize the waste water

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