Titanium-based heterogeneous amination composite catalyst and application of titanium-based heterogeneous amination composite catalyst in production of N-methyl pyrrolidone for liquid crystal panel

Abstract

The invention discloses a titanium-based heterogeneous amination composite catalyst which comprises the following components in percentage by mass: 25-35% of Ti, 5-10% of Si, 2-10% of Co, 2-5% of Mn,1-3% of Mo, 0.5-1.0% of Mg, 0.2-0.5% of Ag and the balance of a carrier. The invention also provides a method for producing N-methyl pyrrolidone for a liquid crystal panel by using the catalyst. The method comprises a reaction section, an intermittent purification section, a gas stripping purification section and a secondary rectification purification section. The N-methyl pyrrolidone product canreach the SEMI C8 standard completely by innovating reaction raw materials, a reaction process and a purification process and strictly controlling process parameters without traditional fiber filtration, and the quality of the product can basically reach the SEMI C12 standard after pressurized adsorption filtration.

Description

technical field [0001] The invention relates to the technical field of preparation of fine chemical products, in particular to a titanium-based heterogeneous amination composite catalyst and its application in the production of N-methylpyrrolidone for liquid crystal panels. Background technique [0002] N-Methylpyrrolidone is a fine chemical with excellent performance. Because of its strong dissolving power, it has a strong dissolving power for polar or non-polar substances. It is known as "universal solvent". As a solvent or organic raw material, it is widely used in industrial fields such as coatings, inks, electronic chemicals, advanced cleaning agents, and power lithium-ion batteries. [0003] The dehydration of N-methylpyrrolidone and the removal of metal ions have been widely concerned. For the dehydration of N-methylpyrrolidone, CN101696182A is to dehydrate the N-methylpyrrolidone to be purified through molecular sieve column adsorption, which is limited by adsorption...

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Problems solved by technology

[0004] For the removal of impurity metal ions in N-methylpyrrolidone, U.S. Patent No. 4,965,370 removes impurity metal ions by adding alkali metals or alkali metal salts, and then obtains high-purity NMP through continuous fractional distillation; CN110551051A discloses a method for removing metal ions The method of content and particle size is the technology of amination of methylamine and γ-butyrolactone (GBL) to prepare N-methylpyrrolidone, in which the most critical metal ion particles are removed in the final stage of filtration and demagnetization control stage , but did not explain whether the fiber after filtration needs to be renewed or revived; CN108299266A discloses a method for preparing high-purity N-methylpyrrolidone that uses a permeable air synovial membrane module to remove moisture in the raw material solution, and then passes through strong Acidic styrene-based cation-exchange resin or weakly acidic acrylic-based cation-exchange resin to filter metal ions or particles; CN102399179B The production method of ultra-pure N-methylpyrrolidone uses industrial-grade N-methylpyrrolidone as raw material, pretreated, 4A molecular sieve Adsorption and dehydration, through β-cyclodextrin composite membrane and 18-crown-6-composite membrane for two membrane filtrations, the filtrate is rectified under reduced pressure, the collected fractions are condensed and then passed through a microporous membrane for three-stage membrane filtration, Obtain the target product; CN102190611 and CN102001986A publicly show that resin treatment and filtration are used, but the resin needs regeneration and material replacement, industrial sewage treatment and material waste are large, and the metal ion content in the product belongs to trace impurities, and the resin regeneration link uses Regeneration solutions such as hydrochloric acid require high-purity reagents, and it is difficult to ensure the content of metal impurities, which indirectly increases the cost of production and environmental protection treatment, and is not suitable for industrial production and purification.

But generally speaking, the above-mentioned methods have complicated operation process, difficult operation control, high energy consumption and low efficiency.

[0005] In addition, the purity of N-methylpyrrolidone in China is currently between 99.5% and 99.9%, and its metal particle content is basically between 20 and 30ppb. The national standard has not yet proposed the control requirements for the particle size of N-methylpyrrolidone, but domestic Liquid crystal panel enterprises generally require the content of metal ions in N-methylpyrrolidone to be ≤5ppb, and the particle content to be ≤5 / ml (0.5μm)

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