Method and system for irradiation-chemical method combined treatment of plant fibrous agricultural wastes

Abstract

The invention provides a method for irradiation-chemical method combined treatment of plant fibrous agricultural wastes. The method comprises the following steps: pretreating the plant fibrous agricultural wastes, then carrying out dynamic irradiation and crushing treatment, weighing treated wastes, pouring the treated wastes into a reactor, adding a solvent, carrying out a reaction, and carryingout vacuum filtering so as to obtain a filtrate A and a filter residue, subjecting the filter residue to washing and drying so as to obtain cellulose, then subjecting the filtrate A to reduced pressure concentration, adding distilled water into a concentrate so as to extract a lignin precipitate, carrying out filtering so as to obtain a filtrate B and a filter residue, subjecting the filter residue to washing and drying so as to obtain lignin, subjecting the filtrate B to reduced pressure concentration, and carrying out collection so as to obtain xylose. The invention also provides a system for irradiation-chemical method combined treatment of the plant fibrous agricultural wastes. The method provided by the invention uses common and easily-available reagents like formic acid in all steps,has low cost, and facilitates large-scale popularization and application; and compared with the prior art, the method improves production efficiency, and is a green and environment-friendly treatmentmethod.

Description

technical field [0001] The invention belongs to the technical field of utilization of biomass resources, and in particular relates to a method and a system for jointly treating plant fibrous agricultural wastes through irradiation and chemical methods. Background technique [0002] Plant fibrous agricultural waste refers to renewable and reusable waste rich in cellulose, mainly including crop straw, such as corn straw, rice straw, rape straw, etc., and also includes by-products of agricultural product processing, such as tea seed husk , bagasse, corncobs, cottonseed hulls, etc. my country's agricultural waste resources are very rich, with hundreds of millions of tons of agricultural waste resources generated every year. At present, such resources are often stacked and incinerated, which not only causes waste of resources, but also seriously pollutes the environment. Abundant agricultural waste is a valuable renewable resource. "Use is beneficial, discarding is harmful." Ac...

AI Technical Summary

Problems solved by technology

Both the acid method and the alkali method have the problem of environmental pollution

Organic solvent separation method, using organic or aqueous organic solvent mixture plus inorganic acid catalyst to destroy the chemical bond between internal lignin and hemicellulose, commonly used organic solvents include methanol, ethanol, acetone, ethylene glycol, ethylene glycol and four Hydrogen furfuryl alcohol, organic solvent method first started in the paper industry, has the advantages of high separation efficiency, small lignin structure changes, etc., but at the same time there are limitations such as corrosion and toxicity, which is easy to cause environmental pollution

[0005] Chinese patent document CN106192514A discloses a separation and purification process of lignin, cellulose and hemicellulose, which uses NaOH solution to carry out alkali pre-extraction of biomass containing lignin, hemicellulose and cellulose, and then through screw extrusion , to obtain the alkali pre-extraction solution and the biomass after alkali pre-extraction, the alkali pre-extraction solution is separated and concentrated by nanofiltration membrane, acid hydrolysis, centrifugal separation, nanofiltration membrane separation and other steps to remove lignin, semi The cellulose and cellulose are fully separated, and the recovery rate of this method is high. However, the extraction temperature of this method is higher than 100°C, and the energy consumption is high. At the same time, the use of nanofiltration membranes further increases the cost.

Chinese invention patent CN103030815A provides a method for comprehensive utilization of cellulose, hemicellulose and lignin in biomass raw materials. Under the catalysis of hydrogen peroxide, the biomass raw materials are cooked by mixing organic acids such as formic acid and acetic acid. Cellulose, lignin and hemicellulose can be extracted separately, and the three lines can be comprehensively and stably carried out, which improves the extraction rate of the three products. However, the reaction temperature of the dehydration and carbonization step of this method is high, and many types of organic solvents need to be used.

Chinese invention patent CN105484083A discloses a green process for separating lignin components. The process pretreats biomass by irradiation, coupled with low-boiling point tetrahydrofuran or high-boiling point γ-lactyl ester reaction, and obtains cellulose components by primary filtration. The hemicellulose component and lignin component are obtained by filtering for the first time. The advantage of this invention is that the lignocellulose component can be separated without adding any acid, alkali and alcohol. The process is simple and efficient. However, this invention also exists The reaction temperature is high, and the tetrahydrofuran or gamma-lactyl organic solvent used pollutes the environment

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