Composite catalytic membrane applied to catalytic esterification and preparation method thereof

Abstract

Provided are a composite catalytic membrane for catalyzing an esterification reaction and a preparation method thereof. The composite catalytic membrane has a porous structure, with non-woven fabric as the base film, and a catalytic coating is compounded on the surface of the non-woven fabric and in the pores and gaps of the non-woven fabric fibers. The catalytic coating uses a solid acid as a catalyst to polymerize Compound or modified sulfonated polymer is used as film-forming material, and the film is formed by coating method or impregnation method, and after forming, it is cross-linked to obtain a composite catalytic membrane. Utilizing the microporous structure and developed specific surface of the composite catalytic membrane, the catalytic esterification and the greening and high efficiency of the biodiesel preparation process are realized. The composite catalytic membrane has high mechanical strength and good repetition stability, and is easy to realize the continuous production repetition of the catalytic esterification process. The preparation process is simple and easy to control and scale up.

Description

technical field [0001] The invention belongs to the technical field of membrane materials and catalysis, and in particular relates to a composite catalytic membrane for catalyzing esterification and a preparation method thereof, in particular to a novel composite membrane which can be used for catalytic esterification of organic acids and alcohols and preparation of biodiesel. Catalytic membrane and method for its preparation. The international patent main classification number is proposed to be Int.Cl.B01D71 / 02. Background technique [0002] Organic carboxylic acid esters are important fine chemical products, often used as solvents and fragrances, and can be used in synthetic fragrances, cosmetics, food and feed additives, surfactants, anti-corrosion and anti-fungal agents, plasticizers for rubber and plastics, and pharmaceuticals. Raw materials and intermediates, etc., long-chain organic carboxylic acid esters are also used as biodiesel to replace petrochemical diesel. T...

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Problems solved by technology

However, after the large particle catalyst was reused 3 times, the conversion rate dropped to 89%.

Chinese patent CN101045688 (2007) reported a new type of esterification reaction device, that is, the lactic acid was added to the reaction system containing alcohol and catalyst to react through the porous membrane, and then combined with the pervaporation membrane to remove the lactic acid in the reaction system in time. Water, under the given conditions, the yield of methyl lactate reaches more than 96%, but the catalyst is directly added to the reaction system, which not only makes it difficult to reuse the catalyst, but even pollutes the product.

[0006] Although polymer / solid catalyst hybrid catalytic membranes can be prepared by hybridizing polymers and solid catalysts and exhibit better catalytic efficiency and longer service life, the catalytic membranes prepared by this method are generally dense structures. The solid catalyst on the surface of the membrane can play a catalytic role, but the catalyst on the membrane body is difficult to play a catalytic role, and there are defects in the specific surface area of ​​the catalytic membrane and the low efficiency of the catalyst.

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