Method utilizing continuous countercurrent reaction extraction of pentose solution to produce furfural

Abstract

The invention discloses a method utilizing continuous countercurrent reaction extraction of a pentose solution to produce furfural. The method comprises the following steps: preparing a pentose solution by pantose, acetic acid and water by the mass ratio of (2-20):(3-10):(70-95), taking nitrotoluene as an extraction agent; enabling the pentose solution to enter from the bottom of a reaction extraction column; enabling the extraction agent to enter from the top of thereaction extraction column; filling the raffinate phase obtained from the top of the reaction extraction column into a raffinate phase storage tank, and recycling the raffinate phase after the pentose is supplemented; feeding the extraction phase obtained from the bottom of the reaction extraction column into an extraction agent regenerating column, feeding coarse furfural obtained from the top into a coarse furfural storage tank after being cooled by a cooler, so as to obtain the finished furfural through subsequent refining, and feeding the extraction agent obtained from the bottom into the extraction agent storage tank for recycle. The method provided by the invention has the advantages of high furfural yield rate, low environment pollution and low unit energy consumption.

Description

technical field [0001] The invention belongs to the technical field of furfural production, in particular to a technology for preparing furfural with pentose sugars in the preparation of furfural by a two-step method. Background technique [0002] So far, furfural cannot be extracted from petroleum, but can only be obtained by hydrolyzing plant fibers. In the process of producing furfural, hemicellulose in plant fibers is firstly hydrolyzed under acidic conditions to obtain a pentose sugar solution, and then the pentose sugar is dehydrated and cyclized to form furfural. According to whether the hemicellulose hydrolysis and pentose sugar dehydration in plant fibers are carried out simultaneously in the same reactor, the furfural production process can be divided into one-step method and two-step method. In the current furfural production industry, one-step method is often used, that is, hemicellulose hydrolysis and pentose dehydration are carried out simultaneously in the sa...

AI Technical Summary

Problems solved by technology

Using the traditional one-step production process, every ton of furfural produced produces about 20 tons of waste water and consumes 16-20 tons of steam. The other two components in the plant fiber are destroyed to generate 10-12 tons of waste residue. The highest yield of furfural is only about 45%.

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