Three-waste treatment method for synthesis gas production process and biomass conversion process

Abstract

The invention relates to the technical field of biomass resource utilization, in particular to a three-waste treatment method for a synthesis gas production process and a biomass conversion process. According to the method, the waste residues generated by a biomass conversion process are used as gasification raw materials of the synthesis gas, so that the content of effective synthesis gas in the synthesis gas is increased, the content of impurity gas in the synthesis gas is reduced, the waste residues can be effectively utilized, and effective utilization of resources is realized.

Description

Technical Field

[0001] This invention relates to the field of biomass resource utilization technology, specifically to a method for treating the three wastes of a syngas production process and a biomass conversion process. Background Technology

[0002] Biomass conversion technology is the technical process of converting biomass resources into energy, chemicals, or materials. With technological advancements, biomass conversion technology has undergone significant development from traditional utilization to modern high-efficiency technology. As technology progresses, biomass conversion will play a greater role in the energy, chemical, and materials fields, promoting sustainable development. However, the operation of biomass conversion processes inevitably generates a large amount of wastewater, waste gas, and waste residue. If these are not properly treated, they will not only cause environmental pollution but also waste resources. Wastewater contains acetic acid, volatile organic compounds, and other components; waste gas contains sulfur oxides, nitrogen oxides, and other volatile compounds; and waste residue is mainly biomass residue, containing unconverted lignin and cellulose.

[0003] Currently, most waste treatments employ separate processes to treat the three wastes, but the treatment efficiency and resource utilization are low. In particular, for the treatment of waste residue, existing technologies generally use incineration or landfill to treat the waste residue, which not only leads to the waste of resources but also causes environmental pollution. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of resource waste caused by waste residue treatment in the existing biomass conversion process, thereby providing a syngas production process, wherein the gasification feedstock of the syngas includes waste residue generated by the biomass conversion process.

[0005] In one optional embodiment, the gasification feedstock for the syngas further includes activated carbon; preferably, the activated carbon is waste activated carbon obtained after decolorizing a salt solution.

[0006] In one optional embodiment, the gasification temperature of the gasification feedstock is 800~1600℃; the gasification pressure is 0.05~8MPa; the gasification medium includes at least one of air, oxygen or oxygen-enriched steam; the particle size of the gasification feedstock is less than or equal to 10mm; preferably, the particle size of the gasification feedstock is 0.5~10mm. And / or, the gasification is carried out in a fluidized bed and / or an entrained flow bed.

[0007] In one optional embodiment, when the gasification is carried out in a fluidized bed, the gasification temperature is 800~1100℃; the gasification medium includes at least one of air, oxygen, and steam; the gasification pressure is 0.05~4.5 MPa; the material residence time is 0.5s~30s; and the particle size of the gasification feedstock is 0.5~10mm. And / or, when the gasification is carried out in an entrained flow bed, the gasification temperature is 1100~1600℃; the gasification medium includes at least one of oxygen or oxygen-enriched steam; the gasification pressure is 0.5~8MPa; the material residence time is 0.5s~10s; and the particle size of the gasification feedstock is less than or equal to 0.1mm.

[0008] In one optional embodiment, the gasification feedstock further includes water; preferably, when the gasification feedstock also includes water, the solid content of the gasification feedstock is 30-60 wt%; the viscosity of the gasification feedstock is less than or equal to 2000 mPa·s. And / or, the gasification feedstock further includes coal; preferably, when the gasification feedstock further includes coal, the solid content of the gasification feedstock is 40-70 wt%; And / or, the biomass conversion process includes a hemicellulose extraction process; preferably, the hemicellulose extraction process includes at least one of a furfural production process and a xylitol production process.

[0009] In one alternative embodiment, the salt solution is obtained by treating wastewater generated during a biomass conversion process using metal carbonates. And / or, the mass ratio of activated carbon to waste residue is 1:(4~999), preferably 1:(4~199).

[0010] On the other hand, another technical problem to be solved by the present invention is to overcome the low efficiency of treating the three wastes in the biomass conversion process by a separate process in the prior art, thereby providing a method for treating the three wastes in the biomass conversion process, including the following steps: The waste liquid generated from the biomass conversion process is treated with metal carbonates to obtain a salt solution. The salt solution is then concentrated to obtain by-products and residual liquid. Utilizing residual liquid to absorb waste gas generated during biomass conversion processes; The waste residue generated from the biomass conversion process is used as a gasification feedstock to produce syngas.

[0011] In one optional embodiment, after concentrating the salt solution, the method further includes a step of decolorizing the concentrate; wherein the decolorization is performed using activated carbon. Waste residue and decolorized activated carbon are mixed to form gasification feedstock, which is then gasified to generate syngas.

[0012] In one alternative embodiment, the metal carbonate includes at least one of limestone or dolomite; And / or, the ratio of the metal carbonate to the waste liquid is 1:(12~67), in g:mL; preferably, the ratio of the metal carbonate to the waste liquid is 1:(17~40), in g:mL.

[0013] In one optional embodiment, the salt solution concentration is performed using an evaporation concentration process; Preferably, the conditions for the evaporation and concentration process are: evaporation temperature of 55~70℃, evaporation time of 3~5h, and evaporation pressure of 0.06~0.08MPa; the mass concentration of salt in the concentrated salt solution is 60~70wt%. Preferably, the heat source for evaporation and concentration is provided by the heat generated during the vaporization process.

[0014] In one optional embodiment, the ratio of the concentrate to activated carbon is (20~150):1, in mL:g; preferably (80~120):1, in mL:g. And / or, the concentrated liquid after the decolorization treatment is cooled, crystallized, and filtered to separate by-products and residual liquid; And / or, the mass ratio of the decolorized activated carbon to the waste residue is 1:(4~999), preferably 1:(4~199).

[0015] In one optional embodiment, the method of absorbing waste gas using residual liquid includes spray absorption; preferably, the operating conditions for spray absorption are: a liquid-to-gas ratio of residual liquid to waste gas of (3~10):1, in L:m 3 The exhaust gas residence time is 1-3 seconds; the residual liquid spraying pressure is 0.2-0.5 MPa. And / or, it further includes a step of washing the syngas with residual liquid; preferably, the washing uses residual liquid to spray the syngas; more preferably, the operating conditions for the spraying treatment are: a liquid-to-gas ratio of residual liquid to syngas of (5~15):1, in L:m 3 The exhaust gas residence time is 2-5 seconds; the residual liquid spray pressure is 0.3-0.7 MPa.

[0016] In one optional implementation, the heat generated during the gasification process is supplied to the biomass conversion process via heat exchange. And / or, the gasification temperature is 800~1600℃; the gasification pressure is 0.05~8MPa; the gasification medium includes at least one of air, oxygen or oxygen-enriched steam; the particle size of the gasification feedstock is less than or equal to 10mm; And / or, the gasification is carried out in a fluidized bed and / or an entrained flow bed.

[0017] In one optional embodiment, when the gasification is carried out in a fluidized bed, the gasification temperature is 800~1100℃; the gasification medium includes at least one of air, oxygen, and steam; the gasification pressure is 0.05~4.5 MPa; the material residence time is 0.5s~30s; and the particle size of the gasification feedstock is 0.5~10mm. And / or, when the gasification is carried out in an entrained flow bed, the gasification temperature is 1100~1600℃; the gasification medium includes at least one of oxygen or oxygen-enriched steam; the gasification pressure is 0.5~8MPa; the material residence time is 0.5s~10s; and the particle size of the gasification feedstock is less than or equal to 0.1mm.

[0018] In one optional embodiment, the gasification feedstock further includes water; preferably, when the gasification feedstock also includes water, the solid content of the gasification feedstock is 30-60 wt%; the viscosity of the gasification feedstock is less than or equal to 2000 mPa·s. And / or, the gasification feedstock further includes coal; preferably, when the gasification feedstock further includes coal, the solid content of the gasification feedstock is 40-70 wt%; And / or, the biomass conversion process includes a hemicellulose extraction process; preferably, the hemicellulose extraction process includes at least one of a furfural production process and a xylitol production process.

[0019] The technical solution of this invention has the following advantages: 1. This invention provides a syngas production process, wherein the syngas gasification feedstock includes waste residue generated from a biomass conversion process. This invention utilizes waste residue from a biomass conversion process as the syngas gasification feedstock, which not only increases the effective syngas content and reduces the content of impurity gases in the syngas, but also effectively utilizes the waste residue, achieving efficient resource utilization.

[0020] 2. The present invention provides a syngas production process, wherein the activated carbon is activated carbon that has undergone decolorization treatment. The present invention utilizes the syngas formed from the gasification feedstock obtained by mixing decolorized activated carbon with waste residue. This not only fully utilizes the waste residue resources generated by the biomass conversion process and the decolorized and purified activated carbon, but also increases the effective syngas content and reduces the impurity gas content in the syngas.

[0021] 3. The present invention provides a syngas production process in which coal is also included as a gasification feedstock. By introducing coal for co-gasification, the high carbon content of coal and the high reactivity of biomass waste are synergistically utilized, which can significantly improve the yield of effective gas in syngas compared with the scheme without coal.

[0022] 4. This invention provides a method for treating the three wastes of a biomass conversion process, comprising the following steps: treating the waste liquid generated from the biomass conversion process with metal carbonates to obtain a salt solution; concentrating the salt solution to obtain byproducts and residual liquid; using the residual liquid to absorb the waste gas generated from the biomass conversion process; and using the waste residue generated from the biomass conversion process as gasification feedstock to generate syngas. This invention's method for treating the three wastes of a biomass conversion process can convert acidic components in the waste liquid into salt byproducts, effectively remove waste gas using the residual liquid generated from the waste liquid treatment, and utilize the decolorized activated carbon and waste residue to form gasification feedstock to generate syngas. This not only achieves the synergistic operation of the three waste treatment technologies but also fully utilizes resources and improves resource utilization efficiency. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a flow chart of the waste treatment process for the synthesis gas production and biomass conversion process provided in Embodiment 1 of the present invention. Detailed Implementation The following embodiments are provided to better understand the present invention, but the following embodiments do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the scope of protection of the present invention.

[0025] Unless otherwise specified, the experimental steps or conditions in the examples were performed in accordance with conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0026] Example 1 This embodiment provides a method for treating the three wastes of a syngas production and biomass conversion process (taking furfural production as an example). The process flow is as follows: Figure 1 As shown, the specific steps are as follows: (1) Wastewater treatment: 1.0 g of limestone (CaCO3, industrial grade, particle size less than 150 μm) was added to 40 mL of acidic wastewater generated from the furfural production process, and the mixture was magnetically stirred at 60 °C and 500 rpm for 30 minutes for neutralization. After the reaction was completed, the mixture was centrifuged at 3000 rpm for 5 minutes to separate the solid residue, and the supernatant was collected as a salt solution. The salt solution was placed in a rotary evaporator and evaporated and concentrated at 60 °C and 0.07 MPa vacuum for 4 hours to obtain a concentrated solution, in which the mass fraction of acetate was measured to be 65 wt%. Subsequently, granular activated carbon (particle size 0.5~1 mm) was added to the concentrated solution at a volume-to-mass ratio of 100 mL: 1 g, and the mixture was stirred at 55 °C and 300 rpm for 30 minutes for decolorization. After decolorization, the activated carbon was separated by vacuum filtration to obtain the decolorized salt solution and the decolorized waste activated carbon. After decolorization, the salt solution is cooled, crystallized, and filtered to obtain a byproduct (calcium acetate) and a residual liquid for subsequent steps.

[0027] (2) Waste gas treatment: The residual liquid obtained in step (1) is used to absorb the waste gas from the furfural production process in a countercurrent spray tower (the residual liquid is sprayed downwards from the top nozzle, and the waste gas is introduced upwards from the bottom of the tower). The liquid-to-gas ratio of the residual liquid to the waste gas is controlled at 5L:1m. 3 The spray pressure is 0.3 MPa, and the residence time of the exhaust gas in the tower is 2 seconds. This process can efficiently remove sulfur dioxide (SO2) and nitrogen oxides (NOx) from the exhaust gas. x Acetic acid vapor and other volatile organic compounds are purified before being discharged.

[0028] (3) Gasification treatment: The aldehyde residue (dry basis) generated from the furfural production process is mixed with the waste activated carbon recovered in step (1) at a mass ratio of 4:1 as a raw material for dry powder gasification (without slurry preparation, and the raw material particle size range is 0.5~5mm). The raw material is fed into a bubbling fluidized bed reactor, and the gasification reaction is carried out at 900℃ and 1.0MPa with air as the gasification medium. The gas residence time is about 8 seconds, generating crude syngas, the main components of which are carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2) and a small amount of methane (CH4). The waste heat of the high-temperature flue gas generated by gasification is converted into steam through a heat recovery device, which is used to provide a heat source for the evaporation and concentration process in step (1) and the furfural production process. Subsequently, the crude syngas is sprayed and washed with the residual liquid obtained in step (1) at a liquid-to-gas ratio of 5L:1m. 3 The spraying pressure is 0.3 MPa, and the gas residence time is 2 seconds, resulting in purified syngas. This spraying process can effectively remove ammonia (NH3), hydrogen sulfide (H2S), fine dust, and tar particles from the syngas, thereby obtaining clean, usable syngas that can be used for power generation, heating, or chemical synthesis.

[0029] Example 2 This embodiment provides a method for treating the three wastes of syngas production and biomass conversion process (taking furfural production process as an example), and the specific steps are as follows: (1) Wastewater treatment: 1.0 g of limestone (CaCO3) was added to 40 mL of acidic wastewater generated from the furfural production process, and the mixture was magnetically stirred at 60℃ and 500 rpm for 30 minutes for neutralization. After the reaction was completed, the mixture was centrifuged at 3000 rpm for 5 minutes to separate the solid residue, and the supernatant was collected as a salt solution. The salt solution was placed in a rotary evaporator and concentrated under vacuum conditions of 55℃ and 0.07 MPa for 5 hours to obtain a concentrated solution, in which the mass fraction of acetate was measured to be 70 wt%. Subsequently, granular activated carbon (particle size 0.5~1 mm) was added to the concentrated solution at a volume mass ratio of 80 mL: 1 g, and the mixture was stirred at 70℃ and 300 rpm for 30 minutes for decolorization. After decolorization, the activated carbon was separated by vacuum filtration to obtain the decolorized salt solution and the decolorized waste activated carbon. The decolorized salt solution was cooled, crystallized, and filtered to obtain the byproduct (calcium acetate) and the residual liquid used in subsequent steps.

[0030] (2) Waste gas treatment: The residual liquid obtained in step (1) is used to absorb the waste gas from the furfural production process in a countercurrent spray tower (the residual liquid is sprayed downwards from the top nozzle, and the waste gas is introduced upwards from the bottom of the tower). The liquid-to-gas ratio of the residual liquid to the waste gas is controlled at 15L:1m. 3 The spray pressure is 0.7 MPa, and the residence time of the exhaust gas in the tower is 1 second. This process can efficiently remove sulfur dioxide (SO2) and nitrogen oxides (NOx) from the exhaust gas. x Acetic acid vapor and other volatile organic compounds are purified before being discharged.

[0031] (3) Gasification treatment: The aldehyde residue (dry basis) generated from the furfural production process is mixed with the waste activated carbon recovered in step (1) at a mass ratio of 4:1 as a dry powder gasification raw material (without slurry adjustment, the raw material particle size range is 0.5~5mm). The raw material is fed into a bubbling fluidized bed reactor, and a mixture of air and oxygen (volume ratio of 1:1) is used as the gasification medium. The gasification reaction is carried out at 800℃ and 1.0MPa, with a gas residence time of about 30 seconds, generating crude syngas, the main components of which are carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2) and a small amount of methane (CH4). The waste heat of the high-temperature flue gas generated by gasification is converted into steam through a heat recovery device, which is used to provide a heat source for the evaporation and concentration process in step (1) and the furfural production process. Subsequently, the crude syngas is sprayed and washed with the residual liquid obtained in step (1), with a liquid-to-gas ratio of 5L:1m. 3The spraying pressure is 0.3 MPa, and the gas residence time is 2 seconds, resulting in purified syngas. This spraying process can effectively remove ammonia (NH3), hydrogen sulfide (H2S), fine dust, and tar particles from the syngas, thereby obtaining clean, usable syngas that can be used for power generation, heating, or chemical synthesis.

[0032] Example 3 This embodiment provides a method for treating the three wastes of syngas production and biomass conversion process (taking furfural production process as an example), and the specific steps are as follows: (1) Wastewater treatment: 1.0 g of limestone (CaCO3) was added to 40 mL of acidic wastewater generated from the furfural production process, and the mixture was magnetically stirred at 60℃ and 500 rpm for 30 minutes for neutralization. After the reaction was completed, the mixture was centrifuged at 3000 rpm for 5 minutes to separate the solid residue, and the supernatant was collected as a salt solution. The salt solution was placed in a rotary evaporator and concentrated under vacuum conditions of 70℃ and 0.08 MPa for 3 hours to obtain a concentrated solution, and the mass fraction of acetate was measured to be 60 wt%. Subsequently, granular activated carbon (particle size 0.5~1 mm) was added to the concentrated solution at a volume mass ratio of 150 mL: 1 g, and the mixture was stirred at 70℃ and 300 rpm for 30 minutes for decolorization. After decolorization, the activated carbon was separated by vacuum filtration to obtain the decolorized salt solution and the decolorized waste activated carbon. The decolorized salt solution was cooled, crystallized, and filtered to obtain the byproduct (calcium acetate) and the residual liquid used in subsequent steps.

[0033] (2) Waste gas treatment: The residual liquid obtained in step (1) is used to absorb the waste gas from the furfural production process in a countercurrent spray tower (the residual liquid is sprayed downwards from the top nozzle, and the waste gas is introduced upwards from the bottom of the tower). The liquid-to-gas ratio of the residual liquid to the waste gas is controlled at 5L:1m. 3 The spray pressure is 0.7 MPa, and the residence time of the exhaust gas in the tower is 5 seconds. This process can efficiently remove sulfur dioxide (SO2) and nitrogen oxides (NOx) from the exhaust gas. x Acetic acid vapor and other volatile organic compounds are purified before being discharged.

[0034] (3) Gasification treatment: The aldehyde residue (dry basis) generated from the furfural production process is mixed with the waste activated carbon recovered in step (1) at a mass ratio of 4:1 as a dry powder gasification raw material (without slurry adjustment, the raw material particle size range is 0.5~5mm). The raw material is fed into a bubbling fluidized bed reactor, and a mixture of air and oxygen (volume ratio of 1:1) is used as the gasification medium. The gasification reaction is carried out at 1000℃ and 1.0MPa, with a gas residence time of about 30 seconds, generating crude syngas, the main components of which are carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2) and a small amount of methane (CH4). The waste heat of the high-temperature flue gas generated by gasification is converted into steam through a heat recovery device, which is used to provide a heat source for the evaporation and concentration process in step (1) and the furfural production process. Subsequently, the crude syngas is sprayed and washed with the residual liquid obtained in step (1), with a liquid-to-gas ratio of 5L:1m. 3 The spraying pressure is 0.3 MPa, and the gas residence time is 3 seconds, resulting in purified syngas. This spraying process can effectively remove ammonia (NH3), hydrogen sulfide (H2S), fine dust, and tar particles from the syngas, thereby obtaining clean, usable syngas that can be used for power generation, heating, or chemical synthesis.

[0035] Example 4 This embodiment provides a method for treating the three wastes of a synthesis gas production and biomass conversion process (taking furfural production process as an example). The only difference between this embodiment and Embodiment 1 is that the gasification raw material in step (3) is only furfural residue and does not include the waste activated carbon recovered in step (1). All other conditions are the same as in Embodiment 1.

[0036] Example 5 This embodiment provides a method for treating the three wastes of syngas production and biomass conversion process (taking furfural production process as an example), and the specific steps are as follows: (1) Waste liquid treatment: Same as step (1) in Example 1.

[0037] (2) Waste gas treatment: Same as step (2) in Example 1.

[0038] (3) Gasification treatment: The aldehyde residue (dry basis) generated from the furfural production process is mixed with the waste activated carbon recovered in step (1) at a mass ratio of 30:1 as a dry powder gasification raw material (without slurry adjustment). The above mixed raw material is dried and ground to a particle size of less than 0.1 mm, and then fed into a Shell fluidized bed gasifier. Air is used as the gasification medium, and the gasification reaction is carried out at 1350℃ and 4.0 MPa. The gas residence time is about 5 seconds, generating crude syngas, the main components of which are carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2) and a small amount of methane (CH4). The waste heat of the high-temperature flue gas generated by gasification is converted into steam through a heat recovery device, which is used to provide a heat source for the evaporation and concentration process in step (1) and the furfural production process. Subsequently, the crude syngas is sprayed and washed with the residual liquid obtained in step (1) at a liquid-to-gas ratio of 5L:1m. 3 The spraying pressure is 0.3 MPa, and the gas residence time is 2 seconds, resulting in purified syngas. This spraying process can effectively remove ammonia (NH3), hydrogen sulfide (H2S), fine dust, and tar particles from the syngas, thereby obtaining clean, usable syngas that can be used for power generation, heating, or chemical synthesis.

[0039] Example 6 This embodiment provides a method for treating the three wastes of a synthesis gas production and biomass conversion process (taking furfural production process as an example). The only difference between this embodiment and Example 5 is that the mass ratio of aldehyde residue to waste activated carbon in step (3) is 19:1, the gasification reaction temperature is 1200℃, and all other conditions are the same as in Example 5.

[0040] Example 7 This embodiment provides a method for treating the three wastes of a synthesis gas production and biomass conversion process (taking furfural production process as an example). The only difference between this embodiment and Example 5 is that in step (3), the mass ratio of aldehyde residue to waste activated carbon is 199:1, the temperature of the gasification reaction is 1600℃, the gas residence time in the gasification reaction is 0.5 seconds, and other conditions are the same as in Example 5.

[0041] Example 8 This embodiment provides a method for treating the three wastes of a synthesis gas production and biomass conversion process (taking furfural production process as an example). The only difference between this embodiment and Example 5 is that the mass ratio of aldehyde residue to waste activated carbon in step (3) is 4:1, and all other conditions are the same as in Example 5.

[0042] Example 9 This embodiment provides a method for treating the three wastes of a synthesis gas production and biomass conversion process (taking furfural production process as an example). The only difference between this embodiment and embodiment 8 is that the gasification raw material in step (3) is only furfural residue and does not include the waste activated carbon recovered in step (1). All other conditions are the same as in embodiment 8.

[0043] Example 10 This embodiment provides a method for treating the three wastes of syngas production and biomass conversion process (taking xylitol production process as an example), and the specific steps are as follows: (1) Wastewater treatment: A mixed carbonate consisting of 0.5g limestone (CaCO3) and 0.5g dolomite (CaMg(CO3)2) was added to 40mL of acidic wastewater generated from the xylitol production process. The mixture was stirred at 60℃ and 500rpm for 30 minutes to promote the reaction of acidic substances such as acetic acid and formic acid in the wastewater with carbonates to form salts such as calcium acetate and magnesium acetate. After the reaction was completed, the mixed liquid was centrifuged at 3000rpm for 5 minutes to separate the solid residue and collect the supernatant as a salt solution. The salt solution was placed in a rotary evaporator and concentrated under vacuum conditions of 60℃ and 0.07MPa for 4 hours to obtain a concentrated solution. The mass fraction of acetate in the concentrated solution was measured to be 65wt%. Subsequently, granular activated carbon (particle size 0.5~1mm) was added to the concentrated solution at a volume mass ratio of 100mL:1g, and the mixture was stirred at 55℃ and 300rpm for 30 minutes for decolorization. After decolorization, the activated carbon is separated by vacuum filtration to obtain a decolorized salt solution and decolorized waste activated carbon. The decolorized salt solution is then cooled, crystallized, and filtered to obtain a byproduct (calcium acetate) and a residual liquid for subsequent steps.

[0044] (2) Waste gas treatment: The residual liquid obtained in step (1) is used to absorb the xylitol production process waste gas in a countercurrent spray tower (the residual liquid is sprayed downwards from the top nozzle, and the waste gas is introduced upwards from the bottom of the tower). The liquid-to-gas ratio of the residual liquid to the waste gas is controlled at 5L:1m. 3 The spray pressure is 0.3 MPa, and the residence time of the exhaust gas in the tower is 2 seconds. This process can effectively absorb soluble pollutants such as acetic acid vapor, ammonia, and formaldehyde in the exhaust gas, improving the exhaust gas purification efficiency.

[0045] (3) Gasification treatment: The waste residue (dry basis) from the xylitol production process is mixed with the waste activated carbon recovered in step (1) at a mass ratio of 4:1, and deionized water is added to prepare a slurry gasification feedstock with a solid content of 60wt% and a viscosity of about 1300mPa·s. The feedstock is fed into a quench-type fluidized bed gasifier, and gasification reaction is carried out at 1400℃ and 4MPa with air as the gasification medium. The material residence time is about 5 seconds, generating syngas. The heat of the syngas is recovered through heat exchange and used in the xylitol production process. Subsequently, the crude syngas is sprayed and washed with the residual liquid obtained in step (1) at a liquid-to-gas ratio of 5L:1m 3The spraying pressure is 0.3 MPa, and the gas residence time is 2 seconds, resulting in purified syngas. This spraying process can effectively remove ammonia (NH3), hydrogen sulfide (H2S), fine dust, and tar particles from the syngas, thereby obtaining clean, usable syngas that can be used for power generation, heating, or chemical synthesis.

[0046] Example 11 This embodiment provides a method for treating the three wastes of syngas production and biomass conversion process (taking xylitol production process as an example), and the specific steps are as follows: (1) Waste liquid treatment: Same as step (1) in Example 10.

[0047] (2) Waste gas treatment: Same as step (2) in Example 10.

[0048] (3) Gasification treatment: The waste residue (dry basis) from the xylitol production process is mixed with the waste activated carbon recovered in step (1) at a mass ratio of 30:1, and deionized water is added to prepare a slurry gasification feedstock with a solid content of 60wt% and a viscosity of approximately 1370 mPa·s. The feedstock is fed into a quench-type fluidized bed gasifier, and gasification reaction is carried out at 1200℃ and 6.5 MPa using air as the gasification medium. The material residence time is approximately 5 seconds, generating syngas. The heat of the syngas is recovered through heat exchange and used in the xylitol production process. Subsequently, the crude syngas is sprayed and washed with the residual liquid obtained in step (1) at a liquid-to-gas ratio of 5L:1m 3 The spraying pressure is 0.3 MPa, and the gas residence time is 2 seconds, resulting in purified syngas. This spraying process can effectively remove ammonia (NH3), hydrogen sulfide (H2S), fine dust, and tar particles from the syngas, thereby obtaining clean, usable syngas that can be used for power generation, heating, or chemical synthesis.

[0049] Example 12 This embodiment provides a method for treating the three wastes of syngas production and biomass conversion process (taking xylitol production process as an example), and the specific steps are as follows: (1) Waste liquid treatment: Same as step (1) in Example 10.

[0050] (2) Waste gas treatment: Same as step (2) in Example 10.

[0051] (3) Gasification treatment: The waste residue (dry basis) from the xylitol production process and the waste activated carbon recovered in step (1) are mixed at a mass ratio of 4:1, and deionized water is added to prepare a slurry gasification feedstock with a solid content of 60wt% and a viscosity of about 1300 mPa·s. The feedstock is fed into a quench-type fluidized bed gasifier, and gasification reaction is carried out at 1200℃ and 6.5MPa with air as the gasification medium. The material residence time is about 5 seconds, generating syngas. The heat of the syngas is recovered through heat exchange and used in the xylitol production process. Subsequently, the crude syngas is sprayed and washed with the residual liquid obtained in step (1) at a liquid-to-gas ratio of 5L:1m 3 The spraying pressure is 0.3 MPa, and the gas residence time is 2 seconds, resulting in purified syngas. This spraying process can effectively remove ammonia (NH3), hydrogen sulfide (H2S), fine dust, and tar particles from the syngas, thereby obtaining clean, usable syngas that can be used for power generation, heating, or chemical synthesis.

[0052] Example 13 This embodiment provides a method for treating the three wastes of a synthesis gas production and biomass conversion process (taking xylitol production process as an example). The only difference between this embodiment and Example 10 is that the gasification raw material in step (3) is only xylitol waste residue, and does not include the waste activated carbon recovered in step (1). The viscosity of the slurry gasification raw material is about 1520 mPa·s. All other conditions are the same as in Example 10.

[0053] Example 14 This embodiment provides a method for treating the three wastes of syngas production and biomass conversion process (taking furfural production process as an example), and the specific steps are as follows: (1) Waste liquid treatment: Same as step (1) in Example 1.

[0054] (2) Waste gas treatment: Same as step (2) in Example 1.

[0055] (3) Gasification treatment: The aldehyde residue (dry basis) generated from the furfural production process is mixed with the waste activated carbon and coal powder (dry basis, particle size less than 200 μm) recovered in step (1) at a mass ratio of 40:12:48. Deionized water is added to prepare a slurry gasification feedstock with a solid content of 60 wt% and a viscosity of about 1755 mPa·s. The feedstock is fed into a bubbling fluidized bed reactor, and the gasification reaction is carried out at 1400℃ and 5.0 MPa with air as the gasification medium. The gas residence time is about 5 seconds, generating crude syngas, the main components of which are carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2) and a small amount of methane (CH4). The waste heat of the high-temperature flue gas generated by gasification is converted into steam through a heat recovery device, which is used to provide a heat source for the evaporation and concentration process in step (1) and the furfural production process. Subsequently, the crude syngas is sprayed and washed with the residual liquid obtained in step (1) at a liquid-to-gas ratio of 5 L:1 m3 The spraying pressure is 0.3 MPa, and the gas residence time is 2 seconds, resulting in purified syngas. This spraying process can effectively remove ammonia (NH3), hydrogen sulfide (H2S), fine dust, and tar particles from the syngas, thereby obtaining clean, usable syngas that can be used for power generation, heating, or chemical synthesis.

[0056] Example 15 This embodiment provides a method for treating the three wastes of a synthesis gas production and biomass conversion process (taking furfural production process as an example). The only difference between this method and Example 14 is that the solid content of the slurry gasification feedstock is 70 wt% and the viscosity is about 1848 mPa·s. All other conditions are the same as in Example 14.

[0057] Example 16 This embodiment provides a method for treating the three wastes of a synthesis gas production and biomass conversion process (taking furfural production process as an example). The only difference between this embodiment and Embodiment 14 is that the solid content of the slurry gasification feedstock is 50 wt% and the viscosity is about 1670 mPa·s. All other conditions are the same as in Embodiment 14.

[0058] Example 17 This embodiment provides a method for treating the three wastes of a synthesis gas production and biomass conversion process (taking furfural production process as an example). The only difference between this embodiment and Example 14 is that the gasification raw material in step (3) is a slurry made of furfural residue, coal powder and water, and does not include the waste activated carbon recovered in step (1). The viscosity of the slurry gasification raw material is about 1820 mPa·s. All other conditions are the same as in Example 14.

[0059] Example 18 This embodiment provides a method for treating the three wastes of a synthesis gas production and biomass conversion process (taking furfural production process as an example). The only difference between this embodiment and Example 17 is that no coal powder is added in step (3), and the gasification raw material is only a slurry made of furfural residue and water. The viscosity of the slurry gasification raw material is about 1258 mPa·s. All other conditions are the same as in Example 17.

[0060] Test case The content of each component in the crude syngas produced in step (3) of Examples 1 to 18 was detected by gas chromatography (GC), and the results are shown in Table 1. Among them, the effective syngas percentage refers to the sum of the volume percentages of CO and H2.

[0061] Table 1. Detection results of the composition and content of syngas

[0062] As shown in Table 1, the waste treatment methods provided in Examples 1 to 18 of the invention can all effectively produce syngas, and the quality of syngas can be significantly improved by optimizing the process conditions. Specific analysis is as follows: In Examples 1-3 (fluidized bed gasification, including spent activated carbon), the effective syngas percentage was 54.89%-67.47%, while in Example 4 (fluidized bed gasification, without spent activated carbon), the effective gas percentage decreased to 44.43%. This indicates that introducing spent activated carbon into the fluidized bed system helps improve the syngas quality.

[0063] Examples 5-9 (fluidized bed dry powder gasification, containing waste activated carbon) showed superior performance, with effective gas ratios ranging from 76.37% to 86.64%. Among them, the effective gas ratio of Example 8 (aldehyde residue to waste activated carbon mass ratio 4:1) (86.64%) was significantly higher than that of Example 5 (mass ratio 30:1, 77.04%), indicating that optimizing the raw material ratio can further improve the gasification effect.

[0064] The effective gas percentages in Examples 10-13 (xylitol process slurry gasification, including spent activated carbon) ranged from 66.79% to 70.82%, with Example 12 (waste residue to spent activated carbon mass ratio 4:1) having a relatively high percentage (70.82%). In contrast, Example 13 (without spent activated carbon) had a lower effective gas percentage (66.79%) compared to similar processes. This also indicates that the addition of spent activated carbon plays a positive role in improving syngas quality in the waste treatment process of this invention.

[0065] Comparing Example 17 (aldehyde residue with coal) and Example 18 (aldehyde residue only), under the same slurry system, the addition of coal increased the effective gas ratio from 67.13% to 73.75%, demonstrating the positive effect of coal introduction on improving gasification efficiency. Secondly, in the system containing coal and activated carbon (Examples 14-16), Example 15 (high solids content, 70 wt%) showed a better effective gas ratio (82.56%) than Example 14 (conventional solids content, 60 wt%, 75.89%), while the effect of Example 16 (low solids content, 50 wt%) (67.61%) declined. This indicates that appropriately increasing the solids content is beneficial for obtaining better gasification results.

[0066] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A process for producing syngas, characterized in that, The gasification feedstock for the syngas includes waste residue generated from the biomass conversion process.

2. The synthesis gas production process according to claim 1, characterized in that, The gasification feedstock for the syngas also includes activated carbon; preferably, the activated carbon is waste activated carbon obtained after decolorizing a salt solution.

3. The synthesis gas production process according to claim 1 or 2, characterized in that, The gasification temperature of the gasification feedstock is 800~1600℃; the gasification pressure is 0.05~8MPa; the gasification medium includes at least one of air, oxygen or oxygen-enriched steam; and the particle size of the gasification feedstock is less than or equal to 10mm. And / or, the gasification is carried out in a fluidized bed and / or an entrained flow bed.

4. The synthesis gas production process according to claim 3, characterized in that, When the gasification is carried out in a fluidized bed, the gasification temperature is 800~1100℃; the gasification medium includes at least one of air, oxygen, and steam; the gasification pressure is 0.05~4.5 MPa; the material residence time is 0.5s~30s; and the particle size of the gasification feedstock is 0.5~10mm. And / or, when the gasification is carried out in an entrained flow bed, the gasification temperature is 1100~1600℃; the gasification medium includes at least one of oxygen or oxygen-enriched steam; the gasification pressure is 0.5~8MPa; the material residence time is 0.5s~10s; and the particle size of the gasification feedstock is less than or equal to 0.1mm.

5. The synthesis gas production process according to claim 1, characterized in that, The gasification feedstock also includes water; preferably, when the gasification feedstock also includes water, the solid content of the gasification feedstock is 30~60wt%; the viscosity of the gasification feedstock is less than or equal to 2000mPa·s; And / or, the gasification feedstock further includes coal; preferably, when the gasification feedstock further includes coal, the solid content of the gasification feedstock is 40-70 wt%; And / or, the biomass conversion process includes a hemicellulose extraction process; preferably, the hemicellulose extraction process includes at least one of a furfural production process and a xylitol production process.

6. The synthesis gas production process according to claim 2, characterized in that, The salt solution is obtained by treating the waste liquid generated from the biomass conversion process using metal carbonates; And / or, the mass ratio of activated carbon to waste residue is 1:(4~999), preferably 1:(4~199).

7. A method for treating the three wastes of a biomass conversion process, characterized in that, Includes the following steps: The waste liquid generated from the biomass conversion process is treated with metal carbonates to obtain a salt solution. The salt solution is then concentrated to obtain by-products and residual liquid. Utilizing residual liquid to absorb waste gas generated during biomass conversion processes; The waste residue generated from the biomass conversion process is used as a gasification feedstock to produce syngas.

8. The method for treating waste from biomass conversion process according to claim 7, characterized in that, After concentrating the salt solution, the process also includes a step of decolorizing the concentrate; wherein, activated carbon is used for the decolorization process. Waste residue and decolorized activated carbon are mixed to form gasification feedstock, which is then gasified to generate syngas.

9. The method for treating waste from the biomass conversion process according to claim 7 or 8, characterized in that, The metal carbonate includes at least one of limestone or dolomite; And / or, the ratio of the metal carbonate to the waste liquid is 1:(12~67), in g:mL; preferably, the ratio of the metal carbonate to the waste liquid is 1:(17~40), in g:mL.

10. The method for treating the three wastes of the biomass conversion process according to claim 7, characterized in that, The salt solution is concentrated using an evaporation concentration process. Preferably, the conditions for the evaporation and concentration process are: evaporation temperature of 55~70℃, evaporation time of 3~5h, and evaporation pressure of 0.06~0.08MPa; the mass concentration of salt in the concentrated salt solution is 60~70wt%. Preferably, the heat source for evaporation and concentration is provided by the heat generated during the vaporization process.

11. The method for treating the three wastes of the biomass conversion process according to claim 8, characterized in that, The ratio of the concentrate to activated carbon is (20~150):1, in mL:g; preferably (80~120):1, in mL:g. And / or, the concentrated liquid after the decolorization treatment is cooled, crystallized, and filtered to separate by-products and residual liquid; And / or, the mass ratio of the decolorized activated carbon to the waste residue is 1:(4~999), preferably 1:(4~199).

12. The method for treating waste from biomass conversion process according to claim 7, characterized in that, The method of absorbing waste gas using residual liquid includes spray absorption; preferably, the operating conditions for spray absorption are: the liquid-to-gas ratio of residual liquid to waste gas is (3~10):1, in L:m 3 ; The exhaust gas residence time is 1-3 seconds; the residual liquid spraying pressure is 0.2-0.5 MPa. And / or, it further includes a step of washing the syngas with residual liquid; preferably, the washing uses residual liquid to spray the syngas; more preferably, the operating conditions for the spraying treatment are: a liquid-to-gas ratio of residual liquid to syngas of (5~15):1, in L:m 3 ; The exhaust gas residence time is 2-5 seconds; the residual liquid spray pressure is 0.3-0.7 MPa.

13. The method for treating the three wastes of the biomass conversion process according to claim 7, characterized in that, The heat generated during the gasification process is supplied to the biomass conversion process through heat exchange. And / or, the gasification temperature is 800~1600℃; the gasification pressure is 0.05~8MPa; the gasification medium includes at least one of air, oxygen or oxygen-enriched steam; the particle size of the gasification feedstock is less than or equal to 10mm; And / or, the gasification is carried out in a fluidized bed and / or an entrained flow bed.

14. The method for treating waste from biomass conversion process according to claim 13, characterized in that, When the gasification is carried out in a fluidized bed, the gasification temperature is 800~1100℃; the gasification medium includes at least one of air, oxygen, and steam; the gasification pressure is 0.05~4.5 MPa; the material residence time is 0.5s~30s; and the particle size of the gasification feedstock is 0.5~10mm. And / or, when the gasification is carried out in an entrained flow bed, the gasification temperature is 1100~1600℃; the gasification medium includes at least one of oxygen or oxygen-enriched steam; the gasification pressure is 0.5~8MPa; the material residence time is 0.5s~10s; and the particle size of the gasification feedstock is less than or equal to 0.1mm.

15. The method for treating the three wastes of the biomass conversion process according to claim 7, characterized in that, The gasification feedstock also includes water; preferably, when the gasification feedstock also includes water, the solid content of the gasification feedstock is 30~60wt%; the viscosity of the gasification feedstock is less than or equal to 2000mPa·s; And / or, the gasification feedstock further includes coal; preferably, when the gasification feedstock further includes coal, the solid content of the gasification feedstock is 40-70 wt%; And / or, the biomass conversion process includes a hemicellulose extraction process; preferably, the hemicellulose extraction process includes at least one of a furfural production process and a xylitol production process.

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