A method for producing polyoxymethylene dimethyl ethers from feedstock of concentrated formaldehyde

摘要

Abstract The present invention pertains to the technical field of energy resource chemical industry, and in particular relates to a process for producing polyoxymethylene dimethyl ethers by 5 directly using concentrated formaldehyde aqueous solution as feedstock to catalytically react with methanol and/or methylal in a fixed bed reactor. The method of the present invention uses concentrated formaldehyde aqueous solution with a concentration of over 80% by weight to react with methanol and/or methylal, in the presence of an acidic catalyst, to produce the required polyoxymethylene dimethyl ethers. As compared with using 0 paraformaldehyde powder as feedstock, the method of the present invention accelerates the depolymerization process of paraformaldehyde, thus significantly reduces the time required for product synthesis and makes the synthesis reaction able to be carried out in a fixed bed reactor; meanwhile, as compared with using formaldehyde aqueous solution with a low concentration as feedstock, the method of the present invention also significantly increases 5 the yield rate of the target product.