A kind of refining method for removing trace aldehyde group in 1,3-propanediol

Abstract

The invention relates to a method for removing residual trace impurities containing aldehyde groups in 1,3-propylene glycol (1,3-PDO). The 1,3-PDO solution obtained after the 3-hydroxypropionaldehyde hydrogenation reaction product is dehydrated and concentrated contains a trace amount of aldehyde group impurity, and the sulfonic acid ionic liquid is added to the solution, and the dealdehyde treatment is carried out at a certain temperature, The 1,3-PDO solution after aldehyde removal by rectification under vacuum, and the distillate is condensed to obtain a high-purity 1,3-PDO product. The 1,3-PDO produced by the acrolein hydration route can reduce the residual aldehyde impurity content to less than 10 ppm after adopting this method, and obtain a product with a purity higher than 99.7%, which meets the requirements for the quality of raw materials in the synthesis of low-color polyester PTT. Require. The treatment method is simple to operate, green and efficient, and the acidic ionic liquid can be recycled.

Description

technical field [0001] The invention belongs to the field of purification and purification of chemical synthesis, in particular to a purification method for removing trace aldehyde groups in 1,3-propanediol. Background technique [0002] 1,3-Propanediol (1,3-PDO) is an important organic chemical raw material, which is widely used in organic solvents, lubricants, antifreezes, pharmaceutical intermediates, cosmetics, synthesis of heterocyclic compounds and other fields. , 1,3-PDO also has broad application prospects in thermoplastic polyurethane, copolyester and engineering plastics. At present, its main application is to synthesize a new type of polyester material-polytrimethylene terephthalate (PTT) as a polymerized monomer. [0003] Since the advent of polyethylene terephthalate (PET) fiber, it has been leading the development trend of synthetic fiber. PTT has both the high strength and stability of PET and the excellent molding and processing type of PBT (polybutylene ter...

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Problems solved by technology

[0008] In the above method, the effect of dealdehydeization is poor when using clay and ammonia derivatives, and when acid-base ion exchange resin is used as a catalyst, the dealdehyde effect is good, but the resin itself has the disadvantages of high cost, slow reaction rate, and poor thermal stability. , non-renewable and other shortcomings

[0009] Therefore, in view of the problem of high aldehyde-based impurities in the 1,3-PDO product existing in the above-mentioned acrolein hydration hydrogenation process, it is necessary to find a more effective method to solve the deficiencies in the prior art

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