Production process of safe and low-waste tetrabromoethane

Abstract

The invention relates to a safe and low-waste tetrabromoethane production process, and belongs to the technical field of tetrabromoethane production. The production process comprises the following steps: step 1, adding liquid bromine into a transparent reaction kettle provided with a high-pressure mercury lamp, turning on the high-pressure mercury lamp in a nitrogen atmosphere at a constant temperature of 65-75 DEG C, then introducing acetylene gas, and reacting for 4-5 hours to obtain a reaction solution; step 2, adding ethanol and ethylene glycol glycidyl ether into the reaction liquid in a stirring state to obtain a mixed liquid, and carrying out filter pressing on the mixed liquid by using a modified separation membrane to obtain a permeate liquid; and step 3, recovering ethanol from the permeate through low-temperature distillation, carrying out reduced pressure distillation purification, and finally decolorizing with activated carbon to obtain tetrabromoethane. According to the invention, the reaction of the liquid bromine and the acetylene gas is carried out in the transparent reaction kettle, and the reaction is carried out by raising the temperature under illumination, so that the reaction time is shortened, the generation of reaction byproducts of bromine and the acetylene gas is reduced, and the yield of tetrabromoethane is improved.

Description

technical field [0001] The invention belongs to the technical field of tetrabromoethane production, and in particular relates to a safe and low-waste tetrabromoethane production process. Background technique [0002] Tetrabromoethane is an important chemical additive, mainly used as a cocatalyst in the oxidation process in the production of terephthalic acid, a flame retardant for plastic products such as polystyrene foam, and can also be used as a mineral flotation agent. Tetrabromoethane is produced by the reaction of bromine and acetylene, and the pure product is obtained through neutralization and purification. In the existing tetrabromoethane synthesis process, a batch synthesis process is usually used for the production of tetrabromoethane. The batch synthesis process is mainly that the synthesis process is carried out in a batch synthesis kettle, and a certain amount of bromine is added to the synthesis kettle at one time, and acetylene gas is continuously passed int...

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Problems solved by technology

[0003] However, the batch synthesis process has the following disadvantages: the current production process mainly relies on the heat release of the synthesis reaction to maintain a high reaction rate, mainly based on thermal reaction, but due to many factors such as the volatility of bromine and safety factors, the synthesis reaction temperature Generally maintained within 40°C, the synthesis reaction time is 6-8h, and the time is relatively long, and often accompanied by side reactions. In addition to tetrabromoethane, the synthesis products also contain dibromoethylene, tribromoethane and Impurities such as tribromomethane, and the content of tetrabromoethane in the synthetic liquid are only about 90%

The synthesis time is long and the reaction efficiency is low; acetylene is an extremely dangerous gas, and the production environment requires extremely high fire and explosion protection. When acetylene gas is mixed with air, a mixed gas that is easy to explode is produced, causing serious safety hazards; the production The synthetic liquid produced by the process needs to be washed successively with lye and water to avoid acidity. The neutralized synthetic liquid is then distilled under reduced pressure to obtain the finished product, which requires a large amount of water consumption and produces a large amount of waste water

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