Refining method for removing trace aldehyde group in 1,3-propylene glycol

Abstract

The invention relates to a method for removing residual trace aldehyde group-containing impurities in 1,3-propylene glycol (1,3-PDO). The method comprises: dehydrating and concentrating a 3-hydroxypropionaldehyde hydrogenation reaction product to obtain a 1,3-PDO solution containing trace aldehyde impurities, adding a sulfonic acid ionic liquid into the solution, carrying out aldehyde removal treatment at a certain temperature, carrying out reduced pressure rectification on the aldehyde-removed 1,3-PDO solution, and condensing the distillate to obtain the high-purity 1,3-PDO product. Accordingto invention, 1,3-PDO is produced by the acrolein hydration route; by using the method, the content of the residual aldehyde impurities can be reduced to less than 10 ppm, the product with a purity of higher than 99.7% is obtained, and the requirements of low-chrominance polyester PTT synthesis on the quality of raw materials are met; and the treatment method is simple to operate, and efficient,and the acidic ionic liquid can be recycled.

Description

technical field [0001] The invention belongs to the refining and purifying field of chemical synthesis, in particular to a refining 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, antifreeze agents, pharmaceutical intermediates, cosmetics, synthesis of heterocyclic compounds, etc. , 1,3-PDO also has broad application prospects in thermoplastic polyurethane, copolyester and engineering plastics. At present, its main use is as a polymer monomer to synthesize a new type of polyester material—polytrimethylene terephthalate (PTT). [0003] Since the advent of polyethylene terephthalate (PET) fiber, it has been leading the development trend of synthetic fibers. PTT has both the high strength and stability of PET and the excellent molding processability of PBT (polybutylene terephthalate). Relevant textiles are ...

AI Technical Summary

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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