System and method of manufacturing furol with pentose solution

Abstract

A system using the pentose solution to prepare the furfural is provided, which comprises a dehydration unit and a distillation unit. Wherein, the dehydration unit dehydrates the pentose solution and the distillation unit distills the aldehyde liquid after dehydration to produce the crude aldehyde; the dehydration unit comprises at least two grades of dehydration reactors connected with each otherin series. The system solves the technical problems of low furfural yield, high energy consumption and serious pollution existing in the production process of the current furfural, which is especially suitable for the second step process in the preparation method of the furfural.

Description

technical field [0001] The invention relates to a technology for preparing furfural from a pentose sugar solution. Specifically, it is a system and method for preparing furfural in series with multi-stage dehydration reactors. Background technique [0002] Furfural, also known as furan formaldehyde, has two double bonds and an aldehyde group on the furan ring. This unique chemical structure can make it undergo oxidation, hydrogenation, chlorination, nitration and condensation reactions to produce many chemical products. , so it is widely used in many production fields such as pesticides, medicines, petrochemicals, food additives, and casting. [0003] Furfural is produced from plant fibers rich in pentosans, such as corncobs, corn stalks, grasses, bagasse, cottonseed hulls, rice husks, etc. The principle is that pentosans in plant fibers are first hydrolyzed into pentosans sugars, and then dehydration of pentose sugars to furfural, ie [0004] [0005] Pentosan Pentosa...

AI Technical Summary

Problems solved by technology

However, the two-step method often has a relatively complicated process flow, a large initial investment, and the dehydration process conditions are not very mature, so there are many difficulties in popularizing it at present.

[0009] For example, the patent No. US4533743 and US2768176 discloses respectively the method for producing furfural from pentose solution and the method for producing furfural and liquid fuel from bisulfite waste liquid containing pentose, all adopting a dehydration, In the patent No. US4533743, the pentose-containing solution obtained after condensing the aldehyde vapor is returned to the dehydration reactor for further reaction, which requires a large amount of steam and the concentration of the aldehyde vapor generated at the same time is relatively low, and the patented technology only uses The liquid at the bottom of the distillation tower is returned to the phase separator as a solvent after heat exchange, and the waste water produced in other stages is not treated; the patent No. US2766176 is only carried out once due to dehydration, and in order to increase the content of furfural in the generated aldehyde vapor, After the dehydration reaction, a concentrating device is specially set up to concentrate the generated aldehyde vapor, which requires more steam consumption, and the furfural content in the aldehyde vapor directly coming out of the dehydration reactor is low, and this patent technology does not mention it at all The treatment of wastewater at each stage, so a large amount of waste liquid will be generated in the whole preparation process

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