Method for preparing furfural from Juncao by using two-phase method
The two-phase method for preparing furfural from Juncao grass solves the wastewater and waste residue problems of traditional processes, realizes efficient and environmentally friendly furfural production, improves furfural yield and Juncao grass cellulose utilization, and promotes economic and environmental benefits.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-19
- Publication Date
- 2026-05-19
AI Technical Summary
Traditional furfural production processes result in large wastewater discharges and low waste utilization rates, leading to resource waste and environmental pollution, and the furfural yield is also low.
A two-phase method for preparing furfural from Juncao grass involves pulverizing Juncao grass, mixing it with an aqueous solution of catalyst and auxiliaries, and then carrying out a high-pressure hydrolysis reaction to separate the organic and aqueous phases. The solvent and catalyst are recycled, and Juncao grass cellulose is recovered.
It significantly reduces wastewater, waste gas, and waste residue emissions, increases furfural yield, expands the Juncao (a type of grass) industry chain, and increases economic and environmental benefits.
Smart Images
Figure CN122059911A_ABST
Abstract
Description
Technical Field
[0001] This invention provides a method for producing furfural from Juncao grass using a two-phase method, belonging to the field of furfural preparation. Background Technology
[0002] Furfural is a renewable biomass-based platform compound widely used in the food, fragrance, dye, pharmaceutical, pesticide, resin, daily chemical, casting, textile, and petroleum industries, with a wide range of downstream applications. Traditional furfural production processes require approximately 12 tons of corn cobs and 20 tons of steam to produce one ton of furfural, generating about 24 tons of wastewater containing organic compounds such as acetic acid and formic acid. Furthermore, the cellulose and lignin in the raw materials are not fully utilized, resulting in waste residue. This not only wastes resources but also, if not properly treated, can severely pollute the environment. In traditional furfural production processes, steam is used to separate furfural from the reaction system. However, due to vapor-liquid equilibrium limitations, the steam in furfural production contains very little furfural, with most being water vapor. Therefore, using steam to separate furfural is the fundamental reason for high energy consumption and large wastewater volume. Chinese patent CN112020168B discloses a method for catalytically preparing furfural from corn cobs, which involves mixing corn cob water and an organic solvent, adding inorganic salts, reacting at 130-170 degrees Celsius, and then distilling the organic phase to obtain furfural. Organic phase extraction improves furfural yield and recycles both organic and aqueous phases, reducing wastewater discharge. However, the treatment of corn cob waste remains a significant pollution problem. Juncao (a type of grass) is a perennial herb bred by Chinese scientists to address the conflict between fungi and forests. Its growth cycle is much shorter than that of trees and other forest resources; its root system continues to grow after harvesting. With a holocellulose content exceeding 60%, it is an excellent biomass raw material for producing renewable platform chemicals. Currently, Juncao cultivation is mainly used for cultivating edible fungi, improving soil, and preventing wind erosion and sand fixation. Developing Juncao-to-furfural technology can promote the development of a plant recycling industry chain, bringing widespread economic benefits to society.
[0003] This application addresses the problems of large wastewater discharge and low waste utilization rate in the traditional corn cob furfural production process, and aims to provide a two-phase method for producing furfural from corn cob. Summary of the Invention
[0004] To solve the above problems, the technical solution adopted by the present invention is as follows:
[0005] A method for producing furfural from Juncao grass using a two-phase method includes the following steps: (1) crushing Juncao grass into 8-60 mesh; (2) mixing catalyst / auxiliary agent with water to prepare an aqueous solution; (3) mixing Juncao grass, aqueous solution and organic solvent in a high-pressure reactor for hydrolysis reaction; (4) after the reaction, separating the organic phase first, and distilling to obtain furfural and recover the organic solvent; (5) performing solid-liquid separation on the remaining mixture to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue, the solid residue being Juncao grass cellulose; (6) recycling the organic solvent and aqueous phase (catalyst / auxiliary agent) respectively.
[0006] The organic solvent is one or more of benzene, toluene, methyl isobutyl ketone, and dichloromethane.
[0007] The catalyst is one or more of sulfuric acid, hydrochloric acid, phosphoric acid, oxalic acid, maleic acid, and citric acid. The concentration of the catalyst in the aqueous solution is 0.5 mol / L to 2.0 mol / L, preferably 0.1 mol / L to 1.5 mol / L, and more preferably 0.5 mol / L to 1.2 mol / L.
[0008] The auxiliary agent is one or more of sodium chloride, potassium chloride, lithium chloride, and magnesium chloride, and the concentration of the auxiliary agent in the aqueous solution is 0.1wt% to 10.0wt%, preferably 0.5wt% to 5.0wt%, and more preferably 1.0wt% to 3.0wt%.
[0009] The solid-liquid mass ratio of the Juncao granules to water in the aqueous phase is 1.0wt%-50wt%, preferably 5.0wt%-30wt%, and more preferably 8.0wt%-20wt%.
[0010] The volume ratio of the organic phase to the aqueous phase is 0.5:1 to 10:1, preferably 1:1 to 5:1, and more preferably 2:1 to 4:1.
[0011] The hydrolysis reaction temperature in step 3 is 140-240℃, preferably 150-220℃, more preferably 170-190℃, and the hydrolysis reaction time is 5-300min, preferably 10-240min at 140-240℃, more preferably 15-120min.
[0012] The hemicellulose content of the aforementioned Juncao fiber is less than 2%, and the cellulose content is more than 50%, which can be used to prepare high-value chemicals, pulp or boards.
[0013] Beneficial effects:
[0014] This invention uses a two-phase method to prepare furfural from raw biomass fungi grass. The aqueous phase (catalyst / auxiliary agent) and organic solvent recycling system is green and environmentally friendly. The recovered fungi grass cellulose can be used to prepare high-value chemicals and pulp, which significantly reduces the emission of wastewater, waste gas and waste residue, expands the fungi grass industry chain, and has high comprehensive added value. It has significant cost and environmental advantages, and can achieve a win-win situation for economic and environmental benefits. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the process flow of the present invention. Detailed Implementation
[0016] The invention can be better understood through the following examples. However, the description is for illustrative purposes only and should not, and will not, limit the invention as detailed in the claims.
[0017] Example 1 (Standard)
[0018] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 88%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 60% and a hemicellulose content of 0.2%.
[0019] Example 2 (Acid Concentration Variation)
[0020] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.1 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200°C for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 75%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 54% and a hemicellulose content of 1.6%.
[0021] Example 3 (Acid Concentration Change)
[0022] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 2.0 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200°C for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent through distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 60%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 51% and a hemicellulose content of 0%.
[0023] Example 4 (Variable Solid-Liquid Ratio)
[0024] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 5 grams of Juncao, 100 ml of the aqueous solution, and 200 ml of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 90%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 59% and a hemicellulose content of 0.1%.
[0025] Example 5 (Variable Solid-Liquid Ratio)
[0026] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 50 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 52%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 51% and a hemicellulose content of 1.9%.
[0027] Example 6 (Variable Temperature)
[0028] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 160℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 55%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 50% and a hemicellulose content of 1.8%.
[0029] Example 7 (Variable Temperature)
[0030] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 220℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 51%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 58% and a hemicellulose content of 0.3%.
[0031] Example 8 (Variable Time)
[0032] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 15 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 52%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 50% and a hemicellulose content of 1.9%.
[0033] Example 9 (Variable Time)
[0034] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. An aqueous solution was prepared by mixing sulfuric acid, sodium chloride, and water, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 120 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 54%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 57% and a hemicellulose content of 0.1%.
[0035] Example 10 (Organic phase / water ratio)
[0036] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 50 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent through distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 56%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 54% and a hemicellulose content of 1.2%.
[0037] Example 11 (Organic phase / water ratio)
[0038] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 500 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent through distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 90%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 59% and a hemicellulose content of 0.2%.
[0039] Example 12 (Variable Additive Concentration)
[0040] First, the "Oasis No. 1" Juncao powder was crushed to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 0.5 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 78%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 60% and a hemicellulose content of 0.3%.
[0041] Example 13 (Variable Additive Concentration)
[0042] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 5.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 88%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 59% and a hemicellulose content of 0.15%.
[0043] Example 14 (Changed Organic Phase)
[0044] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of benzene were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent through distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 87%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 58% and a hemicellulose content of 0.3%.
[0045] Example 15 (Changed Organic Phase)
[0046] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of toluene were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent through distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 82%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 53% and a hemicellulose content of 0.8%.
[0047] Example 16 (Changed Organic Phase)
[0048] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. A solution of sulfuric acid, sodium chloride, and water was prepared, with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of dichloromethane were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent through distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 79%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 56% and a hemicellulose content of 0.2%.
[0049] Example 17 (Types of Acidification)
[0050] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. Hydrochloric acid, sodium chloride, and water were mixed to prepare an aqueous solution with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 88%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 60% and a hemicellulose content of 0.2%.
[0051] Example 18 (Types of Acidification)
[0052] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. Phosphoric acid, sodium chloride, and water were mixed to prepare an aqueous solution with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 78%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 50% and a hemicellulose content of 1.2%.
[0053] Example 19 (Types of Acidification)
[0054] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. Oxalic acid, sodium chloride, and water were mixed to prepare an aqueous solution with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 75%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 51% and a hemicellulose content of 0.15%.
[0055] Example 20 (Types of Acidification)
[0056] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. Maleic acid, sodium chloride, and water were mixed to prepare an aqueous solution with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride mass concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200 °C for 45 min. After the reaction, the organic phase was separated and the furfural was recovered by distillation. The remaining mixture was subjected to solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of the two phases was tested, and the final furfural yield was calculated to be 70%. The compositional analysis of the recovered Juncao cellulose showed that the cellulose content was 50% and the hemicellulose content was 1.7%.
[0057] Example 21 (Types of Acidification)
[0058] First, the Juncao "Oasis No. 1" was pulverized to 8-60 mesh. Citric acid, sodium chloride, and water were mixed to prepare an aqueous solution with a sulfuric acid concentration of 0.6 mol / L and a sodium chloride concentration of 2.0 wt%. 15 g of Juncao, 100 mL of the aqueous solution, and 200 mL of methyl isobutyl ketone were mixed and placed in a high-pressure reactor for hydrolysis at 200℃ for 45 min. After the reaction, the organic phase was separated, and furfural was recovered as the organic solvent by distillation. The remaining mixture underwent solid-liquid separation to obtain an aqueous phase containing catalyst / auxiliary agent and a solid residue (Juncao cellulose). The furfural mass of both phases was tested, and the final furfural yield was calculated to be 72%. Component analysis of the recovered Juncao cellulose showed a cellulose content of 54% and a hemicellulose content of 1.8%.
Claims
1. A method for producing furfural from sphagnum moss using a two-phase process, characterized in that, Includes the following steps: (1) Crush the Juncao grass into 8-60 mesh; (2) Mix the catalyst / auxiliary agent with water to prepare an aqueous solution; (3) Mix the Juncao grass, the aqueous solution and the organic solvent and place them in a high-pressure reactor for hydrolysis reaction; (4) After the reaction is completed, first separate the organic phase, and then distill it to obtain furfural to recover the organic solvent; (5) Separate the remaining mixture into a solid-liquid mixture to obtain an aqueous phase containing the catalyst / auxiliary agent and a solid residue, the solid residue being Juncao grass cellulose; (6) Recycle the organic solvent and the aqueous phase (catalyst / auxiliary agent) respectively.
2. The method according to claim 1, characterized in that, The organic solvent is one or more of benzene, toluene, methyl isobutyl ketone, and dichloromethane.
3. The method according to claim 1, characterized in that, The catalyst is one or more of sulfuric acid, hydrochloric acid, phosphoric acid, oxalic acid, maleic acid, and citric acid. The concentration of the catalyst in the aqueous solution is 0.5 mol / L to 2.0 mol / L, preferably 0.1 mol / L to 1.5 mol / L, and more preferably 0.5 mol / L to 1.2 mol / L.
4. The method according to claim 1, characterized in that, The auxiliary agent is one or more of sodium chloride, potassium chloride, lithium chloride, and magnesium chloride, and the concentration of the auxiliary agent in the aqueous solution is 0.1wt% to 10.0wt%, preferably 0.5wt% to 5.0wt%, and more preferably 1.0wt% to 3.0wt%.
5. The method according to claim 1, characterized in that, The solid-liquid mass ratio of the Juncao granules to water in the aqueous phase is 1.0wt%-50wt%, preferably 5.0wt%-30wt%, and more preferably 8.0wt%-20wt%.
6. The method according to claim 1, characterized in that, The volume ratio of the organic phase to the aqueous phase is 0.5:1 to 10:1, preferably 1:1 to 5:1, and more preferably 2:1 to 4:
1.
7. The method according to claim 1, characterized in that, The hydrolysis reaction temperature in step 3 is 140-240℃, preferably 150-220℃, more preferably 170-190℃, and the hydrolysis reaction time is 5-300min, preferably 10-240min at 140-240℃, more preferably 15-120min.
8. The method according to claim 1, characterized in that, The hemicellulose content of the aforementioned Juncao fiber is less than 2%, and the cellulose content is more than 50%, which can be used to prepare high-value chemicals, pulp or boards.