System and method for producing furol with agricultural and forestry castoff

Abstract

The invention discloses a system and method to prepare furfural with agricultural wastes, which is characterized by the following: choosing two-step method; comprising hydrolysis system and dehydration distilling system; setting the hydrolysis system as at least two grade cascading hydrolysis unit; proceeding hydrolysis for the agricultural wastes; generating hydrolysis acid liquor with pentose; setting the dehydration distilling system as dewatering unit and distilling unit; setting the dewatering unit at least two grade cascading dewatering reactor; proceeding dehydration for the hydrolysis acid liquor; transferring pentose to furfural; distilling for the furfural steam with the distilling unit; refining; getting the product. This invention possesses high productivity, low energy consumption and warm reacting condition, which can be used as raw material to produce alcohol.

Description

technical field [0001] The invention relates to the field of furfural production, in particular to a system and method for preparing furfural from agricultural and forestry waste through a two-step process. Background technique [0002] Furfural, also known as furan formaldehyde, has a unique chemical structure of two double bonds and an aldehyde group on the furan ring, which allows furfural to undergo oxidation, hydrogenation, chlorination, nitration and condensation reactions, and produces many chemical products, so it is widely used It is widely used in many production fields such as pesticides, pharmaceuticals, petrochemicals, food additives, and casting. [0003] Furfural is produced from pentosan-rich straw, which is the main agricultural and forestry waste, and consists of cellulose, hemicellulose, and lignin in an approximate ratio of 4:3:3. Its production principle is that the pentosan in the plant fiber is firstly hydrolyzed into pentose sugar, and then the pento...

AI Technical Summary

Problems solved by technology

[0010] The method disclosed in this patent for the production of furfural from plant matter is formally a two-step process, that is, the hydrolysis of plant matter and the dehydration of pentose sugars are carried out in different reactors, but in fact the hydrolysis in the first step More furfural has been produced during the process, which means that the temperature and pressure of plant material hydrolysis are high, the degree of hydrolysis is deep, and the cellulose and lignin in the solid raw material after hydrolysis are destroyed, that is, the two-step method is immature. , an incomplete two-step method

In addition, the technical solution disclosed in this patent also has the following disadvantages: (1) only one reaction tank is used to carry out the dehydration reaction of pentose, and the conversion of pentose is not complete, so that the conversion rate of furfural is also relatively low; ( 2) The acid solution in the furfural production process and the aqueous solution containing pentose sugars are sent back to the hydrolysis tank to participate in the reaction after adjusting the pH and concentration, which fully shows that there are still unreacted pentose sugars after hydrolysis, dehydration and other steps. sugar, so the pentose conversion is insufficient; (3) in this patent document, the catalyst is disclosed in the cycle of volatile organic acids, but the cycle of the organic acid is only the cycle of acid in the hydrolysis process of vegetable matter, and the pentose In the dehydration process, a new inorganic acid, sulfuric acid, was added as a catalyst for the dehydration reaction. In this patent document, the treatment of sulfuric acid and wastewater after the reaction was not mentioned, so not all acids and wastewater in this patent were recycled; (4) This patent achieves the separation of slag and liquid by setting a sieve at the bottom of the hydrolysis tank, which cannot further refine the solid matter

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