Heteropoly acid catalyzed process to eliminate micro aldehyde group from 1,3-propylene glycol

Abstract

The heteropoly acid catalyzed process to eliminate micro aldehyde group from 1, 3-propylene glycol includes: adding heteropoly acid, salt of heteropoly acid or solid carried heteropoly acid catalyst into 1, 3-propylene glycol solution, obtained through dewatering 3-hydroxy propanal hydrogenating product and certain amount of aldehyde group, to eliminate aldehyde group; and decompression rectifying 1, 3-propylene glycol solution after eliminating aldehyde group to obtain 1, 3-propylene glycol product with purity higher than 99.6 % and aldehyde content lower than 10 ppm and meeting the requirement as polyester PTT producing material.

Description

technical field

[0001] The invention relates to the removal of trace aldehyde groups in 1,3-propanediol and its refining and purification method. Background technique

[0002] 1,3-propanediol is an important new organic chemical raw material, which can be used as a monomer for the synthesis of polyester and polyurethane. Polyester (PTT) synthesized from 1,3-propanediol is better than polyester (PET) synthesized from ethylene glycol and polyester (PBT) synthesized from 1,4-butanediol. Excellent, PTT fiber not only has the performance of PET and PBT, but also has good resilience and anti-pollution performance of nylon. However, due to the high price of 1,3-propanediol, the high production cost of PTT limits its market competition with PET and PBT. Since Degussa adopted the acrolein route and Shell adopted the ethylene oxide route to achieve large-scale industrial production of 1,3-propanediol in the 1990s, the good development prospects of PTT have aroused widespread interes...

Examples

Embodiment 1

[0013] Put 250g of concentrated solution containing 1,3-propanediol and 5g of phosphotungstic acid (HPW) (Keggin structure) in a 500ml three-neck flask equipped with a magnetic stirrer, and immerse the flask in a hot water bath, at 40 ° C, stirring Under the condition of reaction 1h. The solution after dealdehydeization was rectified under reduced pressure. The number of theoretical plates in the rectification tower was 28, the temperature of the bottom of the tower was 147°C, the reflux ratio was 10:1, and the operating pressure was 2kPa. The content of 1,3-propanediol in the overhead distillate product exceeds 99.6%. The results are shown in Table 1.

Embodiment 2

[0015] The dealdehyde reaction and rectification operating conditions are the same as in Example 1, and the catalyst is changed to phosphomolybdic acid. The results are shown in Table 1.

Embodiment 3

[0017] The dealdehyde reaction and rectification operating conditions are the same as in Example 1, and the catalyst is changed to silicotungstic acid. The results are shown in Table 1.

technical field

[0001] The invention relates to the removal of trace aldehyde groups in 1,3-propanediol and its refining and purification method. Background technique

[0002] 1,3-propanediol is an important new organic chemical raw material, which can be used as a monomer for the synthesis of polyester and polyurethane. Polyester (PTT) synthesized from 1,3-propanediol is better than polyester (PET) synthesized from ethylene glycol and polyester (PBT) synthesized from 1,4-butanediol. Excellent, PTT fiber not only has the performance of PET and PBT, but also has good resilience and anti-pollution performance of nylon. However, due to the high price of 1,3-propanediol, the high production cost of PTT limits its market competition with PET and PBT. Since Degussa adopted the acrolein route and Shell adopted the ethylene oxide route to achieve large-scale industrial production of 1,3-propanediol in the 1990s, the good development prospects of PTT have aroused widespread interes...

Examples

Embodiment 1

[0013] Put 250g of concentrated solution containing 1,3-propanediol and 5g of phosphotungstic acid (HPW) (Keggin structure) in a 500ml three-neck flask equipped with a magnetic stirrer, and immerse the flask in a hot water bath, at 40 ° C, stirring Under the condition of reaction 1h. The solution after dealdehydeization was rectified under reduced pressure. The number of theoretical plates in the rectification tower was 28, the temperature of the bottom of the tower was 147°C, the reflux ratio was 10:1, and the operating pressure was 2kPa. The content of 1,3-propanediol in the overhead distillate product exceeds 99.6%. The results are shown in Table 1.

Embodiment 2

[0015] The dealdehyde reaction and rectification operating conditions are the same as in Example 1, and the catalyst is changed to phosphomolybdic acid. The results are shown in Table 1.

Embodiment 3

[0017] The dealdehyde reaction and rectification operating conditions are the same as in Example 1, and the catalyst is changed to silicotungstic acid. The results are shown in Table 1.