Waste gas treatment and methyl mercaptan recycling process in cimetidine and ranitidine production

Abstract

The invention discloses a waste gas treatment and methyl mercaptan recycling process in cimetidine and ranitidine production. The waste gas treatment and methyl mercaptan recycling process comprises the following steps: (1) introducing waste gas in the production process of cimetidine and ranitidine into a washing tank, controlling pressure to 0.2-0.3MPa, removing volatile substances which are low in boiling point and easily soluble in water in the waste gas; (2) introducing the waste gas subjected to washing treatment into an alkaline washing tank, controlling pressure to 0.2-0.3MPa, removing volatile substances which are insoluble in water and soluble in alkaline by alkaline liquor in the alkaline washing tank; (3) introducing the waste gas subjected to the alkaline washing into a three-stage absorbing device, removing methyl mercaptan in the waste gas to generate sodium thiomethoxide; and (4) introducing the waste gas subjected to the three stages of absorption into a hydrogen peroxide falling film absorbing tower for performing oxidation treatment, and then discharging. According to the waste gas treatment and methyl mercaptan recycling process, useful chemical raw materials in the waste gas are recycled on the basis of solving the problem of waste gas emission, and thus the waste gas is prevented from being discharged, the economic benefit is increased, a new value is created, and the recycling economy is realized. The waste gas treatment and methyl mercaptan recycling process is good in application prospect.

Description

technical field [0001] The invention relates to a waste gas treatment and methyl mercaptan recovery process in the production of cimetidine and ranitidine, belonging to the technical field of energy saving and environmental protection. Background technique [0002] Cimetidine (Cimetidine) and ranitidine (Ranitidine) are currently the most widely used drugs for the treatment of ulcer disease. Developed by the British company Glaxo. It was synthesized by British Price in 1976, and its pharmacology was clarified by Bradshaw in 1979. In 1980, Berstad reported that it was effective for duodenal ulcer. Apps in hundreds of countries. [0003] The wide application of cimetidine and ranitidine in the treatment of gastric diseases will inevitably promote the continuous mass production of raw materials. However, in the production process of raw materials, methyl mercaptan, methyl sulfide, monomethylamine, Workshop exhaust gases such as carbon disulfide and nitromethane. Methyl merc...

AI Technical Summary

Problems solved by technology

However, the method of incineration has two disadvantages: on the one hand, the combustion value of methyl mercaptan gas and methyl sulfide gas is relatively high, and a flame of several meters is generated during combustion, and the heat generated at the same time is easy to burn out the incinerator, which has serious consequences for the safety of chemical production. On the other hand, the combustion method cannot fundamentally solve the odor problem, and the air pollution situation is still severe. This is because the combustion is incomplete, and the odor is difficult to eliminate. People's sense of smell is particularly sensitive to the perception of mercaptans. Air pollution

Some manufacturers use a proprietary incinerator to incinerate first and then use a chlorine dioxide generator to eliminate odors. Although this method has a certain improvement effect on the elimination of odors, it requires proprietary equipment, which increases the cost of waste gas treatment. Sulfur dioxide in the air still exists

Images