Hydrogenation catalyst filling method

Abstract

The invention discloses a hydrogenation catalyst filling method. According to the hydrogenation catalyst filling method, grading filling is adopted, and a fixed bed reactor and two hydrogenation catalysts of different sizes are provided; the larger hydrogenation catalyst is injected into the upper part and the lower part of an internal cavity of the fixed bed reactor, and the smaller hydrogenationcatalyst is injected into the middle part of the internal cavity of the fixed bed reactor. The invention also discloses a method used for preparing 1,4-Butanediol (BDO) via high pressure hydrogenation of 2-Butyne-1,4-diol (BYD) based on the hydrogenation catalyst filling method. The method is capable of reducing the contents of BYD high pressure hydrogenation by-product butanol and impurities, reducing influences of catalyst residue on BYD hydrogenation catalysts in BYD preparation process, and prolonging the service life of the BYD hydrogenation catalysts.

Description

technical field [0001] The present invention relates to the technical field of preparation of 1,4-butanediol (BDO), in particular, to a filling method of a hydrogenation catalyst used in a fixed-bed reactor, and a method based on the filling method through 1, A method for preparing BDO by high-pressure hydrogenation of 4-butynediol (BYD). technical background [0002] BDO is an important fine chemical product, mainly used in the production of tetrahydrofuran (THF), γ-butyrolactone (GBL), polybutylene terephthalate (PBT), polyurethane (PU), copolyester ether (COPEs), polytetramethylene glycol ether, N-methylpyrrolidone (NMP), polyvinylpyrrolidone (PVP), etc. Taking PBT as an example, in recent years, PBT is mainly used in PBT modification, PBT drawing, PBT drawing film, optical fiber sheath and other fields. Home appliances, textiles, machinery, and communications. In addition, it is also used in the synthesis of vitamin B6, pesticides, herbicides and solvents, wetting agen...

AI Technical Summary

Problems solved by technology

However, since the synthesis of BYD by alkynylation uses an unsupported powdered copper-bismuth catalyst and there is no deionization process of the BYD solution, the crushing of the copper-bismuth catalyst and the copper-bismuth ions will inevitably enter the high-pressure hydrogenation section with the BYD solution, resulting in copper-bismuth hydrogenation. The deposition on the surface of the catalyst blocks the pores of the hydrogenation catalyst and covers the active sites of hydrogenation, further causing an increase in side reactions. After hydrogenation, the butanol content in the BDO solution increases, and the acetal 2-(4'-hydroxybutoxy)-tetrahydrofuran ( TBA) increases, product quality decreases, and catalyst life becomes shorter

At the same time, the existing hydrogenation catalysts in the industry are filled with a mixed filling method, which will cause high dealumination at the bottom during the activation process, and the uneven activation caused by the mixed size of particles, small particles with higher activity at the bottom are more susceptible to copper The impact of bismuth ions, combined with various factors, currently the BDO unit in the industry replaces the catalyst more frequently, the shortest is only 2-3 months, and each replacement of the catalyst takes up a lot of production time, which seriously affects the economic benefits and product quality of the factory.

At the same time, the existing high-pressure hydrogenation catalyst is filled with mixed particles of large and small sizes, and small particle catalysts will also exist in the upper part of the catalyst bed, so it is inevitable that the small particle catalysts will be brought into the follow-up equipment. The follow-up equipment is generally expensive imported high-pressure Liquid-phase circulation pump and high-pressure gas-phase circulation compressor, small particle catalysts will cause certain risks to the operation of subsequent equipment, increase equipment maintenance costs, and cause device shutdown in severe cases

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