3 results about "Partial hydrogenation" patented technology

The application discloses a device for dynamically separating oil and water and partially hydrogenating benzene into cyclohexene and a method thereof. The device comprises a reaction unit and a catalyst recovery unit connected in sequence. The reaction unit is composed of multiple series-connected reaction kettles. The catalyst recovery unit comprises a water washing tank, a flash tank, an evaporation kettle, an evaporation water tank and a condenser. After benzene, hydrogen and zinc sulfate aqueous solution containing catalysts pass through the multiple series-connected reaction kettles, oil and water are separated in the water washing tank, the oil phase is sent out of the system after water washing, the water phase flows out from the bottom of the water washing tank, part of the water phase is returned to the reaction kettle, and the other part is sequentially introduced into the flash tank and the evaporation kettle and then returned to the reaction kettle. The cyclohexene preparation method based on the device can greatly reduce the consumption of catalysts and zinc sulfate.

The present application is directed to the rectifying still residue of high-temperature chlorination synthesis of 2,3-dichloro-5-trichloromethylpyridine. Through the steps of cooling, crushing, partial hydrogenation dechlorination, hot filtration, cold filtration, leaching, drying, etc., the by-products produced in the production process of 2,3-dichloro-5-trichloromethylpyridine, such as 2,3,6-trichloro-5-trichloromethylpyridine, 2,3,4-trichloro-5-trichloromethylpyridine, 2,4-dichloro-5-trichloromethylpyridine, 2,6-dichloro-5-trichloromethylpyridine, are finally converted into a mixed solution mainly containing 2-chloro-5-methylpyridine, 2-chloro-5-chloromethylpyridine, 2,3-dichloro-5-methylpyridine. The solution can be applied to the synthesis of 2,3-dichloro-5-trichloromethylpyridine, thereby achieving the purpose of resource utilization of hazardous waste.

This invention provides a method for producing high-purity 3-methyl-1-penten-3-ol through a water washing and reuse process. Using 3-methyl-1-pentyn-3-ol as a raw material, partial hydrogenation is performed using a catalyst, controlling the incomplete conversion of the raw material (conversion rate ≤98%) to significantly reduce the formation of the over-hydrogenation byproduct 3-methyl-3-pentanol. Then, the partially hydrogenated reaction solution is treated with water washing to extract the incompletely converted 3-methyl-1-pentyn-3-ol to the aqueous phase, which is then returned to the acetylation process. Finally, the water-washed reaction solution is distilled to obtain high-purity 3-methyl-1-penten-3-ol. This invention is novel in its approach. By controlling the incomplete conversion of the raw material in the partial hydrogenation reaction, the formation of over-hydrogenation byproducts is reduced, thereby improving reaction selectivity and atom utilization. Furthermore, utilizing the slightly water-soluble nature of the reactant 3-methyl-1-pentyn-3-ol, the water washing method achieves a simple and efficient separation of the raw material and product. The separated raw material is directly returned to the acetylation process for recycling, without generating additional waste.