Method for preparing polymethoxy dimethyl ether from concentrated formaldehyde serving as raw material

Abstract

The invention belongs to the technical field of energy and chemical industry and particularly relates to a process for directly preparing polymethoxy dimethyl ether from a concentrated formaldehyde solution serving as a raw material by virtue of a fixed bed reactor reaction. The method comprises the following step of reacting a more than 80% concentrated formaldehyde aqueous solution as the raw material and methanol and / or methylal under the condition of an acidic catalyst to prepare the required polymethoxy dimethyl ether. According to the method, since the more than 80% concentrated formaldehyde aqueous solution is adopted as the raw material, the depolymerization process of paraformaldehyde during the synthesis process is omitted so that the reaction time is greatly shortened and the entire reaction can be performed in the fixed bed reactor reaction; and meanwhile, the more than 80% concentrated formaldehyde aqueous solution is selected for reaction and the problem of lower reaction yield caused by adopting a low-concentration formaldehyde aqueous solution for reaction is greatly solved.

Description

Technical field [0001] The invention belongs to the technical field of energy and chemical industry, and specifically relates to a process for preparing polymethoxy dimethyl ether by directly taking concentrated formaldehyde solution as a raw material into a fixed bed reactor for reaction. Background technique [0002] Surveys in recent years have shown that my country’s apparent consumption of diesel has reached about 167 million tons, making diesel supply tight frequently (the domestic demand ratio of diesel and gasoline is about 2.5:1, while the current output ratio is about 2.3:1) . In addition to institutional reasons such as the unreasonable pricing of different types of oil products and the slow linkage between domestic refined oil prices and international crude oil prices, the fundamental reason is the restriction of resource shortages. Traditionally, diesel production is based on petroleum. China's relatively "rich coal, poor oil, and low gas" resource endowments have ma...

AI Technical Summary

Problems solved by technology

[0012] For this reason, the technical problem to be solved by the present invention is that the process reaction time of preparing polyoxymethylene dimethyl ether in the prior art is longer, and causes its reactor to be limited and should first react the problem of yield, and then provide a kind of to concentrate Formaldehyde is used as raw material to prepare according to the method of methoxy dimethyl ether to shorten the reaction time, and the whole reaction can be applied to fixed bed reactor operation, which can effectively improve the reaction yield