Extraction liquid and extraction method for sulphuric acid in sulfuric acid hydrolysate prepared with plant fibre

Abstract

The invention discloses an extract liquid of sulfuric acid from the sulfuric acid hydrolysate of plant fibrous materials and an extraction method thereof. The extract liquid consists of an amine extractant, a diluent and a phase modifier. The sulfuric acid hydrolysate of the plant fibrous materials is fully contacted with the extract liquid to obtain sugar solution containing a little sulfuric acid and the extract liquid containing lots of sulfuric acid; and the extract liquid containing lots of sulfuric acid is fully contacted with stripping agent ammonia or water to obtain the extract liquid containing a little sulfuric acid and ammonium sulfate solution or sulfuric acid solution, the extract liquid and the sulfuric acid solution can be used circularly and ammonium sulfate can be used as fertilizer. The sulfuric acid in the sulfuric acid hydrolysate of the plant fibrous materials can be extracted and recycled simply and economically by the method of the invention, and especially the sulfuric acid is recycled when dilute sulfuric acid with comparatively high concentration is used for hydrolyzing hemicellulose under normal pressure, which has application significance as an acidproof and voltage withstanding cooking boiler is not needed. The extract liquid and the method of the invention are also applicable to extracting and recycling acid when inorganic acid such as hydrochloric acid is used as the hydrolysis catalyst of the plant fibrous materials.

Description

[0001] Field [0002] The invention belongs to the field of biochemical industry, and specifically relates to an extract of sulfuric acid in a plant fiber raw material sulfuric acid hydrolyzate and a method for using the extract to extract sulfuric acid in a plant fiber raw material sulfuric acid hydrolyzate. Background technique [0003] The use of renewable resource cellulose to produce liquid fuels and chemical products can effectively alleviate the problem of the depletion of fossil energy such as petroleum. The use of plant fiber raw materials to produce liquid fuels and chemical products is to hydrolyze hemicellulose and cellulose into sugars, such as oligosaccharides or monosaccharides, and then use microbial fermentation to produce liquid fuels and chemical products. Commonly used methods for hydrolyzing hemicellulose and cellulose into sugars mainly include dilute acid method, concentrated acid method, and enzymatic method, among which sulfuric acid hydrolysis method ...

AI Technical Summary

Problems solved by technology

[0004] U.S. Patent No. 5,562,777 uses strongly acidic ion-exchange resin to absorb sugar in the hydrolyzate and separates and recovers the acid, but it is not practical because the adsorption capacity of ion-exchange resin is very low (2meq / g); U.S. Patent No. 4,608,245 uses C4~C7 alkanols For example, heptanol is used as the first extractant for the first extraction to obtain a raffinate rich in glucose and a first extract rich in sulfuric acid and the first extractant, and then use benzene, CCl4, toluene, etc. for the second extraction The extraction solution that is rich in sulfuric acid and the first extraction agent is extracted for the second time to obtain a raffinate containing only water and sulfuric acid and an extraction solution containing only the first and second extraction agents. The method separates the first and second extractants, then the recovered sulfuric acid, first and second extractants can be recycled, neutralize a small amount of sulfuric acid in the sugar solution with lime, and obtain sugar free of sulfuric acid after filtration liquid, but this method is also impractical due to the high energy consumption of vacuum distillation; Chinese patent application 200710030293.8 discloses a method for recovering sulfuric acid in concentrated acid hydrolyzate of plant cellulose raw materials, which utilizes organic solvents to precipitate oligosaccharides The method solved the problem of economical recovery of sulfuric acid in concentrated acid hydrolyzate, but this method is mainly used in the case of concentrated sulfuric acid hydrolysis, not suitable for dilute sulfuric acid hydrolysis, because monosaccharides are produced under the condition of dilute sulfuric acid instead of oligosaccharides