A method for sulfonating treatment of biomass combusted in a gasifier

Abstract

This invention relates to a method for sulfonating biomass in a gasifier combustion process. The method includes the following steps: Step 1: Pre-treatment of the biomass; Step 2: Sulfonation treatment of the biomass powder; adding the biomass powder and sulfonating agent to a three-necked flask at a mass ratio of 1:1.5-3, followed by the sequential addition of deionized water and catalyst, stirring to ensure uniform mixing, and adjusting the pH to 11-13; Step 3: Placing the three-necked flask from Step 2 in a constant temperature water bath, allowing it to sulfonate at 80-100°C for 4-8 hours; Step 4: Purification; after the sulfonation reaction in Step 3 is completed, adding a 30%-40% ethanol solution to the system until no more precipitate forms, and then filtering to separate the product; Step 5: Drying; this method significantly improves the surface activity and compatibility with coal, achieving a maximum blending ratio of 30% and a single slurry concentration of 61.4%.

Description

Technical Field

[0001] This invention belongs to the field of biomass energy utilization technology, specifically relating to a biomass sulfonation treatment method using a gasifier. Background Technology

[0002] Biomass energy, as a renewable energy source, can reduce fossil fuel consumption and carbon emissions when blended with coal for gasification. However, untreated biomass has a highly hydrophobic surface, poor slurry formation, and low compatibility with coal, resulting in a blending ratio typically below 20%, and the concentration of biomass alone is difficult to exceed 50%, severely limiting its large-scale application in the gasification field.

[0003] In existing technologies, the common methods for treating biomass are baking, carbonization, and liquefaction. Modification methods are mostly concentrated on simple crushing or acid-base treatment, but these have limited effects on improving surface activity. For example, in the study "Research on the Preparation of Coal-Water Slurry Additives and Slurry Forming Properties from Corn Stalks" by Ren Ruipeng et al. of the Key Laboratory of Coal Science and Technology of the Ministry of Education and Shanxi Province at Taiyuan University of Technology, when using lignin extracted from corn stalks as raw material, the unmodified lignin lacked sufficient hydrophilic groups on its surface, making it difficult to effectively reduce slurry viscosity and increase slurry concentration when directly used as a coal-water slurry additive. Furthermore, it was not optimized for the high-proportion blending requirements of gasification co-firing. Most existing treatment methods focus on changing the physical morphology or basic chemical structure of biomass, failing to introduce highly active functional groups. This results in only a small improvement in properties involving surface interactions, such as slurry formation and interfacial compatibility, making it difficult to meet the needs of applications requiring high-proportion blending and high-concentration slurry formation. Summary of the Invention

[0004] The present invention aims to solve the problems of low blending ratio and poor slurry formation in existing biomass gasification co-firing, and provides a biomass sulfonation treatment method for gasification furnace combustion. This method improves the surface properties of biomass through sulfonation process, and achieves the technical effect of a blending ratio of up to 30% and a slurry concentration of 61.4% on its own.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for sulfonating biomass burned in a gasifier, the method comprising the following steps: Step 1: Pre-treat the biomass; ensure the biomass is clean, free of impurities, and dry, then pulverize it to produce biomass powder; Step 2: Sulfonate the biomass powder; add the biomass powder and sulfonating agent to a three-necked flask at a mass ratio of 1:1.5-3, and add deionized water and catalyst in sequence. Stir to mix the above system evenly and adjust the pH to 11-13. Step 3: Place the three-necked flask described in Step 2 in a constant temperature water bath and allow it to undergo sulfonation reaction at 80-100°C for 4-8 hours; Step 4: Purification; After the sulfonation reaction in step 3 is completed, add a 30% to 40% ethanol solution to the system until no more precipitate is formed, and then filter to separate the product. Step 5: Drying; The product separated by filtration in step 4 is washed by repeatedly washing the product with deionized water until the filtrate is neutral. The product is then dried in an oven at 60-80℃ to obtain sulfonated biomass.

[0006] Preferably, the sulfonated biomass obtained in step 5 can be slurried separately and burned in a gasifier, or mixed with coal to form a slurry and co-fired in a gasifier.

[0007] Preferably, when the sulfonated biomass is slurried separately and then burned in the gasifier, the sulfonated biomass is prepared into a slurry with a mass concentration of 50-61.4%; when the sulfonated biomass is mixed with coal and then co-fired in the gasifier, the mass ratio of sulfonated biomass to coal is 2-3:7-8.

[0008] Preferably, the particle size distribution of the sulfonated biomass and coal powder is 5:3:2, with 50% of the particles having a diameter <74μm, 30% having a diameter of 74-100μm, and 20% having a diameter of 100-120μm.

[0009] Preferably, the biomass in step 1 includes one or a mixture of various types of straw, such as corn straw, cotton straw, wheat straw, or rice straw.

[0010] Preferably, the pretreatment in step 1 includes cleaning and removing impurities from the biomass, drying it to constant weight at a temperature of 95-105°C after removing impurities, and then pulverizing the biomass into 80-120 mesh powder after drying to constant weight.

[0011] Preferably, the sulfonating agent in step 2 is selected from the sodium sulfite system of sulfonyl methylating agents.

[0012] Preferably, the amount of deionized water added in step 2 is a solid-liquid ratio of 1:5 to 8; wherein the solid phase includes biomass powder and sulfonating agent.

[0013] Preferably, the catalyst in step 2 is sodium hydroxide, and the amount of sodium hydroxide added is 5-10% of the mass of the biomass powder.

[0014] Preferably, in step 2, a 10% sodium hydroxide solution is used to adjust the pH value within the system.

[0015] Compared with the prior art, the positive and beneficial effects of this invention are as follows: 1. Compared to traditional methods of roasting, carbonizing, and liquefying biomass, this invention involves a relatively lower processing temperature. The sulfonation reaction temperature is controlled at 80–100℃, and the reaction time is 4–8 hours. Compared to traditional roasting (200–300℃) and carbonization (400–600℃) processes, energy consumption is reduced by more than 60%, and the degradation of biomass macromolecules caused by high temperatures (such as a decrease in cellulose polymerization and lignin carbonization) is avoided. After sulfonation treatment, the cellulose retention rate of corn stalks reaches 92%–95%, and the lignin structure integrity maintenance rate is ≥88%, while the retention rate of effective biomass components in traditional carbonization processes is only 60%–70%. Furthermore, the entire process produces no toxic gas emissions, and the solvent recovery rate in the ethanol purification stage is over 85%, meeting the requirements of green chemical production.

[0016] 2. The present invention uses a sulfonation process to treat biomass, which can significantly improve its surface activity and compatibility with coal, achieving the advantages of a maximum blending ratio of 30% and a single slurry concentration of 61.4%.

[0017] 3. The stabilization time of the sulfonated mixed slurry of this invention is 20-35 days, which is 12-22 times longer than that of the unsulfonated biomass mixed slurry (stabilization time ≤ 1.5 days). Even at a high blending ratio of 30%, the proportion of the upper clear liquid is only 2.3% after standing for 30 days, with no sedimentation or agglomeration; while the unsulfonated biomass at a blending ratio of 20% shows obvious stratification after 1.5 days, with the upper clear liquid accounting for 25% and hard sediment forming at the bottom, which cannot meet the requirements for continuous operation of the gasifier (≥ 7 days). The above improvement is due to the stable adsorption layer formed by the sulfonic acid groups on the surface of the sulfonated biomass and the coal particles, which effectively inhibits particle agglomeration and sedimentation through the dual effects of electrostatic repulsion and steric hindrance. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] A method for sulfonating biomass burned in a gasifier, the method comprising the following steps: Step 1: Pre-treat the biomass; ensure the biomass is clean, free of impurities, and dry, then pulverize it to produce biomass powder; Step 2: Sulfonate the biomass powder; add the biomass powder and sulfonating agent to a three-necked flask at a mass ratio of 1:1.5, and add deionized water and catalyst in sequence. Stir to mix the above system evenly and adjust the pH to 11-13. Step 3: Place the three-necked flask described in Step 2 in a constant temperature water bath and allow it to undergo sulfonation reaction at 80-100°C for 4-8 hours; Step 4: Purification; After the sulfonation reaction in step 3 is completed, add a 30% to 40% ethanol solution to the system until no more precipitate is formed, and then filter to separate the product. Step 5: Drying; The product separated by filtration in step 4 is washed by repeatedly washing the product with deionized water until the filtrate is neutral. The product is then dried in an oven at 60-80℃ to obtain sulfonated biomass.

[0020] The sulfonated biomass obtained in step 5 can be slurried alone and burned in a gasifier, or mixed with coal to form a slurry and co-fired in a gasifier. When the sulfonated biomass is slurried alone and burned in a gasifier, the slurry has a mass concentration of 50-61.4%. When the sulfonated biomass is mixed with coal and co-fired in a gasifier, the mass ratio of sulfonated biomass to coal is 2-3:7-8. The particle size distribution of the sulfonated biomass and coal powder is 5:3:2, with 50% of particles <74μm, 30% of particles 74-100μm, and 20% of particles 100-120μm. The biomass in step 1 includes one or a mixture of various types of straw, such as corn stalks, cotton stalks, wheat stalks, or rice stalks. The pretreatment in step 1 includes washing and removing impurities from the biomass. After impurity removal, the biomass is dried at 95–105°C to constant weight, and then pulverized into 80–120 mesh powder. In step 2, the sulfonating agent is selected from the sodium sulfite system of sulfonyl methylation reagents. The amount of deionized water added in step 2 is a solid-liquid ratio of 1:5–8; the solid phase includes biomass powder and the sulfonating agent. The catalyst in step 2 is sodium hydroxide, and the amount of sodium hydroxide added is 5–10% of the mass of the biomass powder. A 10% sodium hydroxide solution is used in step 2 to adjust the pH value of the system.

[0021] The sodium sulfite system in the sulfonation reagent of this invention is derived from the research of authors Lin Rijia, Lu Yongjian, Liu Xilian, et al., entitled "Optimization of Preparation Process of Polypropylene-based Strong Acid Ion Exchange Fibers". Using polypropylene fiber (PP) as the matrix, the advantages and disadvantages of three methods were compared: chlorosulfonic acid sulfonation, sodium sulfite sulfonation, and direct grafting of monomers containing sulfonic acid groups. The results showed that the sodium sulfite sulfonation method can successfully graft -SO3H (sulfonic acid group) onto the surface of PP fibers. Although the reaction time is relatively long, it causes less damage to the mechanical strength of the fibers, and the process is relatively mild. Furthermore, in the study of authors Ren Ruipeng et al., entitled "Research on Preparation of Coal-Water Slurry Additives from Corn Stalks and Slurry Forming Properties", sodium sulfite can form a sulfonating agent with methyl donors such as formaldehyde to achieve the sulfonation process. Therefore, this invention preferably uses the sodium sulfite system prepared in the above-mentioned literature. Unless otherwise specified, the experimental methods described in the examples and comparative examples are conventional methods; reagents, instruments, and materials whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0022] Example 1 A method for sulfonating biomass burned in a gasifier, the method comprising the following steps: Step 1: Pre-treat the biomass; ensure the biomass is clean, free of impurities, and dry, then pulverize it to produce biomass powder; Step 2: Sulfonate the biomass powder; add the biomass powder and sulfonating agent to a three-necked flask at a mass ratio of 1:1.5, and add deionized water and catalyst in sequence. Stir to mix the above system evenly and adjust the pH to 11-13. Step 3: Place the three-necked flask described in Step 2 in a constant temperature water bath and allow it to undergo sulfonation reaction at 100°C for 8 hours; Step 4: Purification; After the sulfonation reaction in step 3 is completed, add a 30% to 40% ethanol solution to the system until no more precipitate is formed, and then filter to separate the product. Step 5: Drying; The product separated by filtration in step 4 is washed by repeatedly washing the product with deionized water until the filtrate is neutral. The product is then dried in a 60°C oven to obtain sulfonated biomass.

[0023] The biomass in step 1 includes corn stalks. The pretreatment in step 1 includes washing and removing impurities from the biomass. After impurity removal, it is dried at 95°C to constant weight, and then pulverized into 80-mesh powder. The sulfonating agent in step 2 is a sodium sulfite system. The amount of deionized water added in step 2 is a solid-liquid ratio of 1:5; the solid phase includes biomass powder and the sulfonating agent. The catalyst in step 2 is sodium hydroxide, and the amount of sodium hydroxide added is 5% of the mass of the biomass powder. A 10% sodium hydroxide solution is used in step 2 to adjust the pH value of the system. The sulfonated biomass has a cellulose retention rate of 93.5% and a lignin structure integrity maintenance rate of 88.6%. In this example, the amount of corn stalks is 100g, sodium sulfite is 150g, deionized water is 1250g, and the catalyst sodium hydroxide is 5g. A portion of the sulfonated corn stalks obtained above is slurried separately, and the other portion is mixed with coal to form a slurry; when slurried separately, the concentration is 60%, and the apparent viscosity is 1100 mPa. The sulfonated corn stalks and local coal were mixed at a ratio of 20% during slurry preparation. After gradation, the slurry concentration was measured to be 65%, with a flowability grade of A and a stability time of 25 days. The particle size distribution of the sulfonated biomass and coal powder was 5:3:2, with 50% of the particles being <74μm, 30% being 74–100μm, and 20% being 100–120μm.

[0024] Example 2 A method for sulfonating biomass burned in a gasifier, the method comprising the following steps: Step 1: Pre-treat the biomass; ensure the biomass is clean, free of impurities, and dry, then pulverize it to produce biomass powder; Step 2: Sulfonate the biomass powder; add the biomass powder and sulfonating agent to a three-necked flask at a mass ratio of 1:3, and add deionized water and catalyst in sequence. Stir to mix the above system evenly and adjust the pH to 11-13. Step 3: Place the three-necked flask described in Step 2 in a constant temperature water bath and allow it to undergo sulfonation reaction at 80°C for 8 hours; Step 4: Purification; After the sulfonation reaction in step 3 is completed, add a 30% to 40% ethanol solution to the system until no more precipitate is formed, and then filter to separate the product. Step 5: Drying; The product separated by filtration in step 4 is washed by repeatedly washing the product with deionized water until the filtrate is neutral. The product is then dried in an 80°C oven to obtain sulfonated biomass.

[0025] The biomass in step 1 is cotton stalks. The pretreatment in step 1 includes washing and removing impurities from the biomass. After impurity removal, it is dried at 105°C to constant weight, and then pulverized into 120-mesh powder. The sulfonating agent in step 2 is a sodium sulfite system. The amount of deionized water added in step 2 is a solid-liquid ratio of 1:8; the solid phase includes biomass powder and the sulfonating agent. The catalyst in step 2 is sodium hydroxide, and the amount of sodium hydroxide added is 10% of the mass of the biomass powder. A 10% concentration of sodium hydroxide is used in step 2 to adjust the pH value of the system. The sulfonated biomass has a cellulose retention rate of 92.1% and a lignin structure integrity maintenance rate of 88.2%. In this example, the amount of cotton stalks is 100 grams, the sulfonated methylating agent is 300 grams, the deionized water is 3200 grams, and the catalyst sodium hydroxide is 10 grams. The sulfonated cotton stalks obtained above were partially pulped separately, and the other part was mixed with coal to form a mixed slurry; when pulped separately, the concentration was 60% and the apparent viscosity was 1050 mPa. The gasification requirements are met. When mixing the slurry, sulfonated cotton stalks are mixed with local coal at a ratio of 30%. After grading and slurry preparation, the slurry concentration is measured to be 65%, flowability grade A, and stability time is 25 days. The particle size distribution of the sulfonated biomass and coal powder is 5:3:2, with 50% of particles <74μm, 30% of particles 74–100μm, and 20% of particles 100–120μm.

[0026] Example 3 A method for sulfonating biomass burned in a gasifier, the method comprising the following steps: Step 1: Pre-treat the biomass; ensure the biomass is clean, free of impurities, and dry, then pulverize it to produce biomass powder; Step 2: Sulfonate the biomass powder; add the biomass powder and sulfonating agent to a three-necked flask at a mass ratio of 1:2.5, and add deionized water and catalyst in sequence. Stir to mix the above system evenly and adjust the pH to 11-13. Step 3: Place the three-necked flask described in Step 2 in a constant temperature water bath and allow it to undergo sulfonation reaction at 90°C for 6 hours; Step 4: Purification; After the sulfonation reaction in step 3 is completed, add a 30% to 40% ethanol solution to the system until no more precipitate is formed, and then filter to separate the product. Step 5: Drying; The product separated by filtration in step 4 is washed by repeatedly washing the product with deionized water until the filtrate is neutral. The product is then dried in a 70°C oven to obtain sulfonated biomass.

[0027] The biomass in step 1 includes wheat straw. The pretreatment in step 1 includes washing and removing impurities from the biomass, followed by drying at 100°C to constant weight, and then pulverizing the biomass into 100-mesh powder. The sulfonating agent in step 2 is a sodium sulfite system. The amount of deionized water added in step 2 is a solid-liquid ratio of 1:6; the solid phase includes biomass powder and the sulfonating agent. The catalyst in step 2 is sodium hydroxide, and the amount of sodium hydroxide added is 8% of the mass of the biomass powder. A 10% sodium hydroxide solution is used in step 2 to adjust the pH value of the system. The sulfonated biomass exhibits a cellulose retention rate of 92.3% and a lignin structure integrity maintenance rate of 88.2%. In this example, the amount of wheat straw is 100 grams, the sulfonated methylating agent is 250 grams, the deionized water is 2100 grams, and the catalyst sodium hydroxide is 8 grams. The sulfonated wheat straw obtained above was partially pulped separately, and the other part was mixed with coal to form a mixed slurry; when pulped separately, the concentration was 60% and the apparent viscosity was 1045 mPa. s; meets gasification requirements; when mixing the slurry, sulfonated cotton stalks are mixed with local coal at a ratio of 25%, and after grading into a slurry, the following are measured: slurry concentration 66%, fluidity grade A, apparent viscosity 1032 mPa. The sulfonation treatment process takes 22 days to stabilize. The particle size distribution of the sulfonated biomass and coal powder is 5:3:2, with 50% of particles <74μm, 30% of particles 74-100μm, and 20% of particles 100-120μm.

[0028] Example 4 A method for sulfonating biomass burned in a gasifier, the method comprising the following steps: Step 1: Pre-treat the biomass; ensure the biomass is clean, free of impurities, and dry, then pulverize it to produce biomass powder; Step 2: Sulfonate the biomass powder; add the biomass powder and sulfonating agent to a three-necked flask at a mass ratio of 1:2, and add deionized water and catalyst in sequence. Stir to mix the above system evenly and adjust the pH to 11-13. Step 3: Place the three-necked flask described in Step 2 in a constant temperature water bath and allow it to undergo sulfonation reaction at 90°C for 7 hours; Step 4: Purification; After the sulfonation reaction in step 3 is completed, add a 30% to 40% ethanol solution to the system until no more precipitate is formed, and then filter to separate the product. Step 5: Drying; The product separated by filtration in step 4 is washed by repeatedly washing the product with deionized water until the filtrate is neutral. The product is then dried in a 75°C oven to obtain sulfonated biomass.

[0029] The biomass in step 1 is rice straw. The pretreatment in step 1 includes washing and removing impurities from the biomass. After impurity removal, it is dried at 105°C to constant weight, and then pulverized into 80-mesh powder. The sulfonating agent in step 2 is a sodium sulfite system. The amount of deionized water added in step 2 is a solid-liquid ratio of 1:7; the solid phase includes biomass powder and the sulfonating agent. The catalyst in step 2 is sodium hydroxide, and the amount of sodium hydroxide added is 6% of the mass of the biomass powder. A 10% sodium hydroxide solution is used in step 2 to adjust the pH value of the system. The sulfonated biomass retains 92.4% cellulose and maintains 88.9% lignin structure integrity. In this example, the amount of wheat straw is 100g, the sulfonated methylation agent is 250g, the deionized water is 2100g, and the catalyst sodium hydroxide is 8g. The sulfonated rice straw obtained above was partially pulped separately, and the other part was mixed with coal to form a mixed slurry; when pulped separately, the concentration was 60% and the apparent viscosity was 1150 mPa. The gasification requirements are met. When mixing the slurry, sulfonated cotton stalks are mixed with local coal at a ratio of 30%. After grading and slurry preparation, the slurry concentration is measured to be 66%, with a flowability grade of A, and a stratification rate of less than 5% within 20 days. The particle size distribution of the sulfonated biomass and coal powder is 5:3:2, with 50% of particles <74μm, 30% of particles 74–100μm, and 20% of particles 100–120μm.

[0030] Example 5 A method for sulfonating biomass burned in a gasifier, the method comprising the following steps: Step 1: Pre-treat the biomass; ensure the biomass is clean, free of impurities, and dry, then pulverize it to produce biomass powder; Step 2: Sulfonate the biomass powder; add the biomass powder and sulfonating agent to a three-necked flask at a mass ratio of 1:2.5, and add deionized water and catalyst in sequence. Stir to mix the above system evenly and adjust the pH to 11-13. Step 3: Place the three-necked flask described in Step 2 in a constant temperature water bath and allow it to undergo sulfonation reaction at 95°C for 5 hours; Step 4: Purification; After the sulfonation reaction in step 3 is completed, add a 30% to 40% ethanol solution to the system until no more precipitate is formed, and then filter to separate the product. Step 5: Drying; The product separated by filtration in step 4 is washed by repeatedly washing the product with deionized water until the filtrate is neutral. The product is then dried in a 66°C oven to obtain sulfonated biomass.

[0031] The biomass in step 1 is a mixture of wheat straw and rice straw, with a weight ratio of 1:1. The pretreatment in step 1 includes washing and removing impurities from the biomass. After impurity removal, it is dried at 105°C to constant weight, and then pulverized into 110-mesh powder. In step 2, the sulfonating agent is a sodium sulfite system. The amount of deionized water added in step 2 is a solid-liquid ratio of 1:5; the solid phase includes biomass powder and the sulfonating agent. The catalyst in step 2 is sodium hydroxide, and the amount of sodium hydroxide added is 9% of the mass of the biomass powder. A 10% sodium hydroxide solution is used in step 2 to adjust the pH value of the system. The sulfonated biomass retains 93.2% cellulose and maintains 88.3% lignin structure integrity. In this example, the amount of wheat straw is 50g, the amount of rice straw is 50g, the sulfonation methylation agent is 250g, the amount of deionized water is 1750g, and the catalyst sodium hydroxide is 9g. The sulfonated biomass obtained above was partially slurried separately, and the other part was mixed with coal to form a mixed slurry; when slurried separately, the concentration was 60% and the apparent viscosity was 1060 mPa. The sulfonated biomass was mixed with local coal at a ratio of 30% to meet gasification requirements. After grading and mixing into a slurry, the slurry concentration was measured to be 65%, the flowability was grade A, and the stability time was 25 days. The particle size distribution of the sulfonated biomass and coal powder was 5:3:2, with 50% of the particles being <74μm, 30% being 74-100μm, and 20% being 100-120μm.

[0032] Example 6 A method for sulfonating biomass burned in a gasifier, the method comprising the following steps: Step 1: Pre-treat the biomass; ensure the biomass is clean, free of impurities, and dry, then pulverize it to produce biomass powder; Step 2: Sulfonate the biomass powder; add the biomass powder and sulfonating agent to a three-necked flask at a mass ratio of 1:1.5, and add deionized water and catalyst in sequence. Stir to mix the above system evenly and adjust the pH to 11-13. Step 3: Place the three-necked flask described in Step 2 in a constant temperature water bath and allow it to undergo sulfonation reaction at 100°C for 8 hours; Step 4: Purification; After the sulfonation reaction in step 3 is completed, add a 30% to 40% ethanol solution to the system until no more precipitate is formed, and then filter to separate the product. Step 5: Drying; The product separated by filtration in step 4 is washed by repeatedly washing the product with deionized water until the filtrate is neutral. The product is then dried in a 60°C oven to obtain sulfonated biomass.

[0033] The biomass in step 1 includes corn stalks. The pretreatment in step 1 includes washing and removing impurities from the biomass, followed by drying at 95°C to constant weight, and then pulverizing the biomass into 80-mesh powder. The sulfonating agent in step 2 is a sodium sulfite system. The amount of deionized water added in step 2 is a solid-liquid ratio of 1:5; the solid phase includes biomass powder and the sulfonating agent. The catalyst in step 2 is sodium hydroxide, and the amount of sodium hydroxide added is 5% of the mass of the biomass powder. A 10% sodium hydroxide solution is used in step 2 to adjust the pH value of the system. The sulfonated biomass exhibits a cellulose retention rate of 94.3% and a lignin structure integrity maintenance rate of 89.1%. In this embodiment, the amount of corn stalks is 100g, sodium sulfite is 150g, deionized water is 1250g, and the catalyst sodium hydroxide is 5g. The sulfonated corn stalks obtained above were partially pulped separately, and the other part was mixed with coal to form a mixed slurry; when pulped separately, the concentration was 61.4% and the apparent viscosity was 1280 mPa. The sulfonated corn stalks and local coal were mixed at a ratio of 30% during slurry preparation. After gradation, the slurry concentration was measured to be 65%, with a flowability grade of A and a stability time of 30 days. The particle size distribution of the sulfonated biomass and coal powder was 5:3:2, with 50% of the particles being <74μm, 30% being 74–100μm, and 20% being 100–120μm.

[0034] Example 7 A method for sulfonating biomass burned in a gasifier, the method comprising the following steps: Step 1: Pre-treat the biomass; ensure the biomass is clean, free of impurities, and dry, then pulverize it to produce biomass powder; Step 2: Sulfonate the biomass powder; add the biomass powder and sulfonating agent to a three-necked flask at a mass ratio of 1:1.5, and add deionized water and catalyst in sequence. Stir to mix the above system evenly and adjust the pH to 11-13. Step 3: Place the three-necked flask described in Step 2 in a constant temperature water bath and allow it to undergo sulfonation reaction at 100°C for 8 hours; Step 4: Purification; After the sulfonation reaction in step 3 is completed, add a 30% to 40% ethanol solution to the system until no more precipitate is formed, and then filter to separate the product. Step 5: Drying; The product separated by filtration in step 4 is washed by repeatedly washing the product with deionized water until the filtrate is neutral. The product is then dried in a 60°C oven to obtain sulfonated biomass.

[0035] The biomass in step 1 includes corn stalks. The pretreatment in step 1 includes washing and removing impurities from the biomass. After impurity removal, it is dried at 95°C to constant weight, and then pulverized into 80-mesh powder. The sulfonating agent in step 2 is a sodium sulfite system. The amount of deionized water added in step 2 is a solid-liquid ratio of 1:5; the solid phase includes biomass powder and the sulfonating agent. The catalyst in step 2 is sodium hydroxide, and the amount of sodium hydroxide added is 5% of the mass of the biomass powder. A 10% sodium hydroxide solution is used in step 2 to adjust the pH value of the system. The sulfonated biomass has a cellulose retention rate of 92.2% and a lignin structure integrity maintenance rate of 88.5%. In this example, the amount of corn stalks is 100g, sodium sulfite is 150g, deionized water is 1250g, and the catalyst sodium hydroxide is 5g. A portion of the sulfonated corn stalks obtained above is slurried separately, and the other portion is mixed with coal to form a mixed slurry; when slurried separately, the concentration is 50%, and the apparent viscosity is 680 mPa. The sulfonated corn stalks and local coal were mixed at a ratio of 10% during slurry preparation. After gradation, the slurry concentration was measured to be 65%, with a flowability grade of A and a stability time of 35 days. The particle size distribution of the sulfonated biomass and coal powder was 5:3:2, with 50% of the particles being <74μm, 30% being 74–100μm, and 20% being 100–120μm.

[0036] Comparative Example A method for treating biomass burned in a gasifier, the method comprising the following steps: Step 1: Pre-treat the biomass; ensure the biomass is clean, free of impurities, and dry, then pulverize it to produce biomass powder; Step 2: Add biomass powder to a three-necked flask, then add deionized water and catalyst in sequence, stir to mix the above system evenly, and adjust the pH to 11-13; Step 3: Add a 30%–40% ethanol solution to the system from Step 2 until no more precipitate forms, then filter to separate the product. Step 4: Drying; The product separated by filtration in step 3 is washed by repeatedly washing the product with deionized water until the filtrate is neutral. The product is then dried in a 60°C oven to obtain unsulfonated biomass.

[0037] The biomass in step 1 includes corn stalks. The pretreatment in step 1 includes washing and removing impurities from the biomass. After impurity removal, it is dried at 95°C to constant weight, and then pulverized into 80-mesh powder. In step 2, the amount of deionized water added is a solid-liquid ratio of 1:5; the solid phase includes biomass powder. The catalyst in step 2 is sodium hydroxide, and the amount of sodium hydroxide added is 5% of the mass of the biomass powder. A 10% sodium hydroxide solution is used in step 2 to adjust the pH value of the system. The unsulfonated biomass has a cellulose retention rate of 98.9% and a lignin structure integrity maintenance rate of 97.5%. In this comparative example, the corn stalks are 100g, the deionized water is 500g, and the catalyst sodium hydroxide is 5g. A portion of the obtained corn stalks is slurried separately, and the other portion is mixed with coal to form a mixed slurry; when slurried separately, the concentration is 60%, and the apparent viscosity is 4500 mPa. The s content does not meet the gasification requirements. When mixing the slurry, unsulfonated corn stalks and local coal were mixed at a ratio of 20%. After grading and slurry preparation, the slurry concentration was measured to be 65%, flowability grade D, and stability time 1.5 days. The particle size distribution of the unsulfonated biomass and coal powder was 5:3:2, with 50% of particles <74μm, 30% of particles 74–100μm, and 20% of particles 100–120μm.

[0038] By randomly comparing Example 1 of the present invention with the comparative examples, firstly, the present invention achieves a breakthrough in core performance through "slight component loss in exchange for core performance improvement" in sulfonation modification. Specifically, after sulfonation treatment, Example 1 exhibits a cellulose retention rate of 93.5% and a lignin structure integrity maintenance rate of 88.6%, only slightly lower than the unsulfonated comparative examples (98.9% and 97.5%), and significantly higher than the 60%–70% effective component retention rate of traditional carbonization processes. By sacrificing a small amount of component integrity, directional grafting of sulfonic acid groups was successfully achieved, resolving the contradiction of "high component retention but performance failure" in unsulfonated biomass. Secondly, the present invention significantly optimizes slurry formation and flowability, meeting the core requirements for gasification. Specifically, when forming slurries alone, at the same 60% concentration, the viscosity of Example 1 is only 1100 mPa. s (meets gasification requirements ≤1500mPa) (s), while the comparative viscosity is as high as 4500 mPa. The concentration of s exceeded the standard by more than 2 times, making stable conveying and atomization impossible. When grading into a slurry, at a 20% blending ratio, Example 1 achieved a flowability grade of A (suitable for continuous industrial conveying) and a stabilization time of up to 25 days; the comparative example showed obvious stratification after only 1.5 days, with a flowability grade of D, completely failing to meet the requirements for continuous operation of the gasifier. Finally, this invention features environmentally friendly and energy-saving processes. The sulfonation reaction temperature in Example 1 is 100℃, and the reaction time is 8 hours, reducing energy consumption by more than 60% compared to traditional baking (200-300℃) and carbonization (400-600℃) processes, with no toxic gas emissions and an ethanol purification solvent recovery rate of over 85%.

[0039] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for sulfonating biomass using a gasifier, characterized in that, The processing method includes the following steps: Step 1: Pre-treat the biomass; ensure the biomass is clean, free of impurities, and dry, then pulverize it to produce biomass powder; Step 2: Sulfonate the biomass powder; add the biomass powder and sulfonating agent to a three-necked flask at a mass ratio of 1:1.5-3, and add deionized water and catalyst in sequence. Stir to mix the above system evenly and adjust the pH to 11-13. Step 3: Place the three-necked flask described in Step 2 in a constant temperature water bath and allow it to undergo sulfonation reaction at 80-100°C for 4-8 hours; Step 4: Purification; After the sulfonation reaction in step 3 is completed, add a 30% to 40% ethanol solution to the system until no more precipitate is formed, and then filter to separate the product. Step 5: Drying; The product separated by filtration in step 4 is washed by repeatedly washing the product with deionized water until the filtrate is neutral. The product is then dried in an oven at 60-80℃ to obtain sulfonated biomass.

2. The biomass sulfonation treatment method using a gasifier combustion according to claim 1, characterized in that: The sulfonated biomass obtained in step 5 can be slurried separately and burned in a gasifier, or mixed with coal to form a slurry and co-fired in a gasifier.

3. The biomass sulfonation treatment method using a gasifier combustion furnace according to claim 2, characterized in that: When the sulfonated biomass is separately slurried and then burned in the gasifier, the sulfonated biomass is produced as a slurry with a mass concentration of 50-61.4%. When the sulfonated biomass and coal are mixed into a slurry and then co-fired in a gasifier, the mass ratio of the sulfonated biomass to the coal is 2-3:7-8.

4. A method for sulfonating biomass using a gasifier as described in claim 2 or 3, characterized in that: The particle size distribution of the sulfonated biomass and coal powder is 5:3:2, with 50% of the particles being <74μm, 30% being 74-100μm, and 20% being 100-120μm.

5. The biomass sulfonation treatment method for combustion in a gasifier according to claim 1, characterized in that: The biomass in step 1 includes one or a mixture of various types of straw, such as corn straw, cotton straw, wheat straw, or rice straw.

6. A method for sulfonating biomass by combustion in a gasifier according to claim 1 or 5, characterized in that: The pretreatment in step 1 includes cleaning and removing impurities from the biomass. After removing impurities, the biomass is dried at a temperature of 95–105°C to constant weight. After drying to constant weight, the biomass is pulverized into 80–120 mesh powder.

7. The biomass sulfonation treatment method for combustion in a gasifier according to claim 1, characterized in that: The sulfonating agent in step 2 is selected from the sodium sulfite system of sulfonyl methylating agents.

8. A method for sulfonating biomass by combustion in a gasifier according to claim 1 or 7, characterized in that: The amount of deionized water added in step 2 is 1:5 to 8 in a solid-liquid ratio; wherein the solid phase includes biomass powder and sulfonating agent.

9. The method for sulfonation treatment of biomass by combustion in a gasifier according to claim 1, characterized in that: In step 2, the catalyst is sodium hydroxide, and the amount of sodium hydroxide added is 5-10% of the mass of the biomass powder.

10. The method for sulfonation treatment of biomass by combustion in a gasifier according to claim 1, characterized in that: In step 2, a 10% sodium hydroxide solution is used to adjust the pH value of the system.