A method for polyoxymethylene dimethyl ether adsorption, membrane separation and dehydration

Abstract

The invention discloses a method for adsorption, membrane separation and dehydration of polyoxymethylene dimethyl ether. The method comprises the following steps: introducing a gas phase material flow raw gas from the top of an adsorption tower I, and performing adsorption reaction in the adsorption tower I; putting a molecular sieve in the adsorption tower I into a regeneration stage after adsorption, and introducing the gas phase material flow raw gas into an adsorption tower II to perform adsorption reaction; at the regeneration stage, under the action of a vacuum pump, discharging a desorption gas from the top of the adsorption tower I, performing membrane separation treatment on the desorption gas, introducing the desorption gas into a raw gas pipeline, and performing adsorption deep dehydration in the next step; after the regeneration in the adsorption tower I, entering an adsorption state again; and after the adsorption in the adsorption tower II, entering the regeneration stage. By adopting the process, on the basis of ensuring the high purity of a product, a high yield is obtained, the desorption gas does not need to be returned to the previous stage distillation process for retreatment at the same time, and the complete independent running of a dehydration working section is realized, so that the method has obvious technical and economic advantages.

Description

technical field [0001] The invention relates to the field of polyoxymethylene dimethyl ether production, in particular to a method for polyoxymethylene dimethyl ether adsorption, membrane separation and dehydration. Background technique [0002] Polyoxymethylene dimethyl ether (referred to as PODE or DMMn), also known as polyoxymethylene dimethyl ether, polyoxymethylene dimethyl ether, polyoxymethylene formal, is a class of dimethoxymethane as the matrix, Low molecular weight acetal polymer with methyleneoxy as the main chain, its general formula is expressed as CH 3 (CH 2 O) nCH 3 , where n is an integer equal to or greater than 1, generally less than or equal to 8. Polyoxymethylene dimethyl ether is a colorless or light yellow volatile and flammable liquid with a slight ether odor. It is a downstream product of methanol. The main production method is from compounds that provide paraformaldehyde (formaldehyde, paraformaldehyde, paraformaldehyde, etc.) and compounds that...

AI Technical Summary

Problems solved by technology

This patent only provides a device structure, and does not give specific process conditions. According to this device structure, those skilled in the art cannot actually achieve the desired effect of the device structure. Such a dehydration device is in the field. In fact, it is relatively common, and those skilled in the art know that process conditions are a very important design link. For different dehydration objects, different process flows and process conditions are required. These are not based on experience or A limited number of trials can obtain

In addition, the disclosed methylal deep dehydration purification device is mainly used to treat methylal, and the water content of methylal is very low, about 0.5%, which is very easy for the molecular sieve itself. If it is controlled below 0.05%, such a dehydration purification device does not have any reference value for the gas phase material flow with a large water content

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