Method and device for producing thiophene and derivant thereof

Abstract

The invention relates to method and device for producing thiophene by synthesizing butadiene and sulfur. The production method comprises the steps of reaction, separation and desulfurization. In the reaction process, raw materials are heated to initial reaction temperature by a water hose heat and intermediate frequency induction heating method, but a reactor does not need to be heated; the reaction is carried out under normal pressure at the temperature of 380-450 DEG C; the molar ratio of the sulfur to the butadiene is 1.2-1.6, the molar ratio of water to the butadiene is 1-2, and the retention time of the reaction is 1-2 seconds. A multistage cooling method is adopted to separate high boiling point tar and unreacted sulfur in a reaction product, thereby solving the problem of blockagesof pipelines and equipment. A freezing and absorbing method is adopted to recover thiophene in hydrogen sulfide which is tail gas, thereby improving the yield of the thiophene. Methods of vapor pressure sealing emptying and two-stage wet desulfurizing are adopted, thereby solving pollution problems of the tar and the hydrogen sulfide in a production process and realizing the cleaning production ofthe thiophene.

Description

technical field [0001] The invention belongs to the field of chemical industry and relates to a production method and device for thiophene and its derivatives. Background technique [0002] Thiophene, also known as thiolane and thiofuran, is the most important sulfur heterocyclic compound and an important organic chemical raw material. It is often used as a reagent for organic synthesis and is widely used in the synthesis of dyes, medicines, pesticides, and polymer additives. Wait. Especially as an important pharmaceutical raw material, thiophene can be used to synthesize hundreds of drugs such as cephalosporins and cephalosporins. There are two types of derivatives of thiophene: α-position (2, 5-position) and β-position (3, 4-position). The α-position is larger than the β-position derivative and has more varieties, but the β-position derivative is expensive, even up to 1000 ten thousand yuan / ton. [0003] The earliest production method of thiophene is to extract from the...

AI Technical Summary

Problems solved by technology

However, the above-mentioned Japanese patents have not been industrialized. One of the possible reasons is that the unreacted sulfur of the reaction product clogs the pipes and condensers after cooling; another possible reason is that the recovery of thiophene in the tail gas cannot be solved. A large amount of thiophene is entrained in the by-product gas hydrogen sulfide (tail gas), which cannot be completely cooled by water condenser alone. Even if the tail gas is frozen by other methods, it can only be cooled to 20°C (if it is lower, the freezer will be blocked) , there is still a large amount of thiophene loss

Chinese patent application (publication numbers are CN 1335313A and CN 1420116A) discloses the production process and equipment of butadiene-sulfur synthetic thiophene, and the reaction adopts the method disclosed in the above-mentioned Japanese patent, and the reaction product is only cooled by a circulating water condenser , thiophene is lost in a large amount from the tail gas, and the consumption (unit consumption) of 1 ton of thiophene raw material butadiene is 1.4 tons (yield 46%) for the former, and 1.8 tons (yield 36%) for the latter; meanwhile, the Chinese patent application (publication numbers are CN 1335313A and CN 1420116A) all heat the reactor, because the reaction is an exothermic reaction, so this is completely unnecessary in fact, but because it adopts resistance wire to heat the reaction raw material, the inlet temperature of the reactor is relatively low , had to heat the reactor

But in this way, the working life of the reactor is reduced, the electric heating efficiency is also affected, and the production cost is increased.

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