With the outbreak of the global energy crisis and the intensification of environmental pollution, the replacement of fossil energy and fossil products with clean and renewable biomass fuels has attracted widespread attention. Among them, the production of biofuels from widely-sourced, cheap, and renewable lignocellulosic biomass, such as agricultural waste, has the most application prospects. Traditional pretreatment methods for the decomposition of biomass into cellulose, hemicellulose and lignin and related products often require extreme conditions and expensive technical means. Therefore, it is of practical significance to develop a greener and cheaper new solvent system to improve the utilization efficiency of lignocellulosic components. CN106480128A provides a green method for extracting hemicellulose by using lactic acid/guanidine hydrochloride to improve the efficiency of enzymatic hydrolysis of cellulose in rice straw, which is specifically as follows:

(1) After drying the rice straw, pulverize it into rice straw powder with an average particle size of 150-350μm;

(2) Using lactic acid/guanidine hydrochloride with a molar ratio of 1:2 to 2:1 as the pretreatment solvent, mix rice straw powder with a mass ratio of 1:5 to 1:25 and the pretreatment solvent at 60 to 130℃ Stir for 0.5-24 hours, then cool to room temperature, add 1 to 3 times the volume of the pretreatment solvent with warm water, filter and wash the filter residue, and dry to obtain pretreated rice straw;

(3) Weigh the pretreated rice straw, add citrate buffer solution (concentration 50mmol/L, pH 4.8) according to the solid-liquid ratio of 1～5mg/mL, and then add commercial cellulase at the ratio of 6-20U/mg pretreated rice straw, and react at a speed of 150-250r/min and a temperature of 40-60℃ to determine the glucose concentration in the hydrolysate. Until the concentration of glucose in the hydrolyzate no longer changes, the reaction is terminated.

Compared with the prior art, this method can obtain higher glucose yield. Using lactic acid/guanidine hydrochloride as the pretreatment solvent for lignocellulose overcomes the disadvantages of traditional ionic liquid pretreatment processes such as unfriendly environment and high cost. At the same time, hemicellulose can be removed by adjusting the types and ratios of hydrogen bond donors and acceptors, and the saccharification yield of cellulose components can be improved.

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