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Continuous catalytic extraction method for preparing polyoxymethylene dimethyl ethers

A technology of polyoxymethylene dimethyl ether and polyoxymethylene dimethyl ether, which is applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., and can solve problems such as separation difficulties

Pending Publication Date: 2019-10-25
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, formaldehyde cannot react completely, which will still cause great difficulties for subsequent separation, including the separation of water in the reaction mixture and the recovery of formaldehyde.

Method used

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  • Continuous catalytic extraction method for preparing polyoxymethylene dimethyl ethers

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0097] The prereactor is a stainless steel fixed bed reactor with an inner diameter of 14mm and a height of 0.3m, filled with 40 ml of strong acidic cation exchange resin catalyst, and the outlet of the prereactor is connected to the heavy phase feed pipe of the catalytic extraction reactor.

[0098] A stainless steel catalytic extraction reactor with an inner diameter of 20mm and a height of 1.3m is filled with 160ml of strongly acidic cation exchange resin catalyst and 200ml of Φ3×3mm stainless steel θ mesh ring, which are evenly mixed. The filling height is 1.2m, and the top 10cm is an empty tube. Set the heavy phase feed pipe at the top of the reactor 1.2m, that is, the top of the catalyst and θ mesh ring bed, set the light phase discharge pipe on the top of the reactor to connect the back pressure valve to control the reaction pressure, and set the light phase feed pipe at the bottom of the reactor , the bottom of the reactor is connected to a temperature-resistant and pre...

Embodiment 2

[0103] Adopt the same prereactor, catalytic extraction reactor, catalyst, catalyst loading method and loading amount as in Example 1.

[0104] 38wt% formaldehyde solution (containing methanol 3wt%) and PODE 1-2 (DMM accounts for 60wt%) enters the prereactor after mixing, and feed rate is respectively 7ml / min, 6ml / min; Methanol feeds from catalytic extraction reactor 0.5m height, feed rate 2ml / min; Adopt cumene The extraction agent is fed from the bottom of the reactor, and the feed rate is 37ml / min; the reaction temperature of the pre-reactor is 60°C, the reaction temperature of the catalytic extraction reactor is 50°C, and the reaction pressure is 0.3MPa.

[0105] The output of the light phase at the top of the reactor is 41.2g / min, including 1.8wt% formaldehyde, 0.74wt% methanol, 0.16wt% water, 7.2wt% DMM, PODE 2 5.1wt%, PODE 3+ 7.5wt%, and the rest are cumene and trace by-products.

[0106] The output of the heavy phase at the bottom of the reactor is 4.9g / min, includin...

Embodiment 3

[0108] The same prereactor, catalytic extraction reactor and catalyst loading method as in Example 1 were used. The difference is that the bar-shaped HZSM-5 molecular sieve catalyst (which contains 20wt% of alumina binder and the molecular ratio of silicon to aluminum of molecular sieve is 38) with 40 milliliters of Φ2×3-5mm in the pre-reactor is filled in the catalytic extraction reactor. Mix uniformly 160 milliliters of Φ2×3-5mm strip-shaped Hβ molecular sieve catalyst (which contains 20 wt% of alumina binder, and the molecular ratio of silicon to aluminum of molecular sieve is 60) and 200 milliliters of Φ3×3mm stainless steel θ mesh ring.

[0109] 30wt% formaldehyde solution (diluted from 38wt% formaldehyde solution, containing 2.4wt% methanol) and PODE 1-2(DMM accounts for 55wt%) enters the prereactor after mixing, and feed rate is respectively 8.3ml / min, 5ml / min; Methanol feeds from catalytic extraction reactor 0.3m height, feed rate 2.4ml / min; Adopt toluene The mixture ...

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Abstract

The invention discloses a continuous catalytic extraction method for preparing polyoxymethylene dimethyl ethers from a methanol and formaldehyde aqueous solution. The method comprises the following steps that (a) a material A containing formaldehyde and a material B containing circular-reacting polyoxymethylene dimethyl ethers are introduced into a pre-reactor for pre-reaction, and thus a pre-reaction material I is obtained; and (b) the pre-reaction material I obtained in the step (a) and a raw material C containing methanol are introduced into a catalytic extraction tower or a multistage catalytic extraction reactor to make countercurrent contact with an extraction agent, and catalytic reaction and extraction are conducted to obtain an extraction phase material II and a raffinate materialIII, wherein the raw material C containing the methanol is fed from the middle of the catalytic extraction tower or a certain stage in the middle of the multistage catalytic extraction reactor. According to the method, the concentration of the polyoxymethylene dimethyl ethers in the extraction phase obtained from the catalytic extraction tower or the multistage catalytic extraction reactor can beincreased, and the method has the advantages that the raw material cost is low, and products are easy to separate.

Description

technical field [0001] The application relates to a continuous catalytic extraction method for preparing polyoxymethylene dimethyl ethers with multiple dimers and above in methanol and formaldehyde aqueous solution. Background technique [0002] Polyoxymethylene dimethyl ether, also known as polyoxymethylene dimethyl ether, polyoxymethylene dimethyl ether, referred to as PODE n (polyoxymethylene dimethyl ethers). [0003] PODE 1 Methylal, also known as dimethoxymethane, or DMM for short, is a colorless, non-toxic and environmentally friendly chemical raw material. It is usually prepared by aldol condensation reaction of methanol and formaldehyde aqueous solution. Due to the presence of a large amount of water (including the water brought in by the formaldehyde aqueous solution and the water generated by the reaction) in the reaction process, the reaction is limited by the chemical balance. At present, catalytic rectification technology is generally used to break the limit ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C41/56C07C41/58C07C43/30
CPCC07C41/56C07C41/58C07C43/30
Inventor 孙新德刘中民于政锡
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI