Technical method and device for preparing polymethoxydimethyl ether by concentrated formaldehyde

Abstract

The invention discloses a process method and a device for preparing polyoxymethylene dimethyl ether from concentrated formaldehyde. It uses methylal and a formaldehyde solution with a concentration of 50% to 88% as raw materials, and reacts to obtain polyoxymethylene dimethyl ether containing polyoxymethylene dimethyl ether. The reaction solution of methyl ether, unreacted formaldehyde aqueous solution and methylal; the reaction solution is sent to the extraction tower from the upper part of the tower after dehydrogenation, and carries out countercurrent contact reaction with the extractant entering from the bottom of the tower, and the reaction solution in the reaction solution Polyoxymethylene dimethyl ether is dissolved in the extractant to obtain an organic phase, and the formaldehyde aqueous solution and the organic phase are separated, and the organic phase is taken out and sent to the extractant recovery tower; the organic phase is sent to the extractant recovery tower for extraction. Atmospheric pressure distillation and separation, recovery of the extraction agent at the top of the tower and polyoxymethylene dimethyl ether with a polymerization degree of 2-8 extracted from the tower bottom. The invention reduces the cost, improves the synthesis conversion rate and the yield is low, and the invention has a good heat transfer effect, can efficiently promote the reaction, and realizes controllability of the conversion degree.

Description

Technical field [0001] The invention belongs to the technical field of chemical production technology and equipment, and mainly relates to the process technology for preparing polymethoxy dimethyl ether from formaldehyde. Background technique [0002] The characteristics of my country's energy structure are: rich in coal, poor in oil, and low in gas. The sustained and rapid economic growth has an increasing demand for energy, and the contradiction between social and economic development and oil supply has become increasingly prominent. Since 2009, my country's dependence on foreign crude oil has exceeded the warning line (50%) for six consecutive years, which has seriously affected my country's energy strategic security. From the perspective of my country's energy strategic security, combined with the characteristics of my country's primary energy structure, the development of coal-based liquid fuel synthesis technology is undoubtedly of strategic importance. In addition, my cou...

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Problems solved by technology

[0006] Purpose of the invention: In view of the above existing problems and defects, the present invention provides a process and device for preparing polyoxymethylene dimethyl ether from concentrated formaldehyde, which solves the cost caused by the current production process of paraformaldehyde / trimerization High, synthetic conversion rate and low yield, and the present invention has a good heat transfer effect, can efficiently promote the reaction, and the degree of conversion is controllable

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