A method for separating highly active lignin from agricultural and forestry biomass

Abstract

The invention discloses a method for separating high-activity lignin from agriculture and forestry biomasses. The method comprises the following steps: (1) smashing and sieving a biomass raw material,performing degreasing and dewaxing treatment and then drying and standing by; (2) adding the biomass raw material acquired in the step (1) into a prepared toluenesulfonic acid / ethyl alcohol system, and controlling reaction temperature at 40-100 DEG C and reaction time within 10-120min, thereby acquiring a mixture; (3) adding hot water into the mixture acquired in the step (2) and performing suction filtration, thereby acquiring a component rich in cellulose, and then cleaning, drying and standing by; (4) continuously adding water into the rest liquid part acquired in the step (3) till the concentration of p-toluenesulfonic acid is below 11.5%, centrifugally separating, separating the solid part and then drying and standing by, performing rotary evaporation concentration on the rest liquidpart, recycling p-toluenesulfonic acid by re-crystallizing, and lastly acquiring the remained hemicellulose and degradation product thereof. The invention mainly concerns the separation of high-activity lignin from agriculture and forestry biomasses and meanwhile realizes the all-component separation of cell walls of agriculture and forestry biomasses.

Description

technical field [0001] The invention belongs to the field of biomass refining and resource utilization, and in particular relates to a method for separating high-activity lignin from agricultural and forestry biomass. Background technique [0002] The utilization of lignocellulose has long had the problem of resource utilization of a single component (Wen, J., Yuan, T., Sun, R., 2017. Biorefining and multistage utilization of lignocellular biomass. Biotechnology and Business, 3, 94-99) Among them, cellulose and hemicellulose (accounting for about 70%) have a relatively simple structure. After separation, paper products, nano-cellulose materials, ethanol, furfural, and hydroxymethylfurfural can be obtained through chemical catalysis or biological fermentation. The remaining 30% lignin, due to its complex structure, cannot achieve effective separation and high value under the existing industrial separation conditions (Sun, S.N., Sun, S.L., Cao, X.F., et al., 2016, The role of...

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Problems solved by technology

However, the annual output of 11 million tons of lignin in my country has an effective utilization rate of less than 20% (Mahmood, N., Yuan, Z.S., Schmidt, J. et al., 2016. Depolymerization of lignins and their applications for the preparation of polyols and rigid polyurethane foams: a review. Renewable & Sustainable Energy Reviews, 60, 317-329.)

However, Chen et al. found in their research that TsOH separated lignin still has a large number of C-C condensation structures at the 2, 5, and 6 positions of its benzene ring, which reduces the high-value potential of separated lignin

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