Biomass waste segmented pyrolysis catalytic gasification hydrogen production process system

Abstract

The invention relates to the technical field of biomass gasification hydrogen production, in particular to a biomass waste segmented pyrolysis catalytic gasification hydrogen production process system. The hydrogen production rate of the biomass gasification hydrogen production technology is low and is difficult to reach more than 700mL / g biomass. In order to solve the technical problems, the invention provides the process system for producing hydrogen through segmented pyrolysis and catalytic gasification of the biomass wastes, and the tar yield in the pyrolysis process is remarkably reduced through graded and stepwise thermochemical conversion by using cheap aluminum smelting waste residues, pyrolysis semicoke and a carbon molecular sieve as catalysts and pyrolysis residues to catalyze tar steam; the aluminum smelting waste residues are coupled with the molecular sieve to catalyze tar cracking, the effect of catalyzing tar cracking for hydrogen production through a cheap nickel-based catalyst is improved, and the hydrogen proportion reaches 70% or above through catalytic reforming of hydrocarbon gas through carbon molecular sieve loaded nickel; the purposes of energy regeneration and reduction of biomass waste and harmless and resource utilization of aluminum smelting waste residues and pyrolysis residues are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of biomass gasification hydrogen production, and in particular to a biomass waste segmented pyrolysis catalytic gasification hydrogen production process system. Background Art

[0002] In recent years, hydrogen has attracted much attention as a clean energy carrier, and its large-scale production technology is mainly concentrated on fossil fuel cracking and reforming, water electrolysis, and industrial by-product gas purification. Currently, about 96% of the world's hydrogen production capacity comes from gray hydrogen (direct cracking of fossil fuels) and blue hydrogen (fossil reforming coupled with carbon capture), but every 1kg of hydrogen produced will be accompanied by more than 10kg of CO 2 Although the production of green hydrogen by electrolysis of water can achieve zero carbon emissions, it only accounts for 4% and is constrained by the high cost of precious metal catalysts, the efficiency bottleneck of electrolyzers and the volatility of renewable energy power, making it difficult to quickly achieve large-scale application.

[0003] Biomass gasification hydrogen production technology has unique advantages due to its raw material renewability and carbon cycle characteristics: by gasifying and converting biomass resources such as agricultural and forestry waste, it can theoretically achieve carbon balance throughout the life cycle; if carbon capture and storage (CCUS) technology is integrated, it can form a negative carbon effect and significantly improve the green carbon sink capacity. However, this technology faces the following core bottlenecks:

[0004] Imbalance of hydrogen-carbon ratio and selectivity defects

[0005] The inherent hydrogen content of biomass raw materials is relatively low (typical H / C atomic ratio is 0.1-0.3). During the pyrolysis stage, hydrogen element preferentially participates in the removal of water and oxygen-containing volatiles (such as CO, CH 4 ) is generated, resulting in insufficient hydrogen selectivity in the gasification product. Experiments show that the hydrogen yield of conventional fluidized bed gasification is generally less than 60g / kg biomass, and the H 2 The volume concentration is mostly below 40%, which makes it difficult to meet the needs of efficient hydrogen production.

[0006] Tar by-products limit system efficiency

[0007] The gasification process is accompanied by the generation of a large amount of polycyclic aromatic hydrocarbons tar (content can reach 20-100g / Nm 3 ), which not only causes energy loss (accounting for 15-30% of the raw material energy), but is also more likely to clog pipelines and poison catalysts. Existing purification technologies (such as cyclone dust removal and catalytic cracking) have problems such as high energy consumption and easy deactivation of catalysts, which significantly increase the operating costs of the system.

[0008] Process coupling and energy optimization challenges

[0009] Biomass gasification requires coordination of multiple reaction stages such as pyrolysis, reforming, and water-gas shift, but the traditional fixed bed / fluidized bed process has insufficient control over the temperature field and gas-solid residence time, resulting in low gasification efficiency (cold gas efficiency is usually less than 70%). At the same time, the lack of integrated optimization of tar treatment and waste heat recovery systems further restricts the improvement of overall energy efficiency.

[0010] Existing improvement plans mostly focus on catalyst modification (such as doping nickel-based catalysts with rare earth elements) or reactor structure optimization (such as dual-bed gasification). Although they can improve local reaction efficiency, they do not fundamentally solve the systemic problems of low hydrogen selectivity and tar coordinated control. Therefore, it is urgent to develop new gasification processes and reaction systems to achieve a dual breakthrough in biomass hydrogen production efficiency and economy by regulating the gasification medium, strengthening in-situ catalysis, and optimizing heat and mass transfer. Summary of the invention

[0011] The problem in the prior art is that the hydrogen production rate of biomass gasification hydrogen production technology is low and it is difficult to reach more than 700mL / g. In view of the above technical problems, the present invention provides a biomass waste staged pyrolysis catalytic gasification hydrogen production process system, comprising the following steps:

[0012] (1) drying and crushing the biomass waste to less than 3 mm;

[0013] (2) The crushed biomass waste obtained in step (1) is continuously added as a material into a cascade pyrolysis device, and the material is processed in a baking section, a heat premixing section, a pyrolysis gasification section, and a catalytic reforming section under the action of gravity to obtain semi-coke and volatile matter, and the semi-coke is regularly discharged from the bottom of the cascade pyrolysis device, and the volatile matter is filtered out of the semi-coke accumulated in the catalytic conversion section to obtain high-temperature pyrolysis gas after fly ash is removed;

[0014] (3) continuously introducing the high-temperature pyrolysis gas into a normal-pressure catalytic converter I, so that the tar in the high-temperature cracking gas undergoes catalytic cracking to obtain a high-hydrogen fuel gas;

[0015] (4) The high-hydrogen fuel gas obtained in the atmospheric pressure catalytic converter I is continuously introduced into the atmospheric pressure catalytic converter II, so that the alkane gas in the high-hydrogen fuel gas undergoes catalytic cracking to produce hydrogen, and hydrogen-rich fuel gas is produced at the bottom of the atmospheric pressure catalytic converter II.

[0016] Preferably, the crushed biomass waste obtained in step (1) is added into the cascade pyrolysis device through a screw feeder, and the feeding rate is 0.5-5 kg / h.

[0017] Preferably, in step (2), the temperature ranges of the baking section, the heat premixing section, the pyrolysis gasification section and the catalytic reforming section are 250-300°C, 500-600°C, 750-800°C and 900-1000°C respectively.

[0018] Preferably, a mixture of pure oxygen and water vapor is continuously introduced into the catalytic reforming section, the air inlet is located in the middle of the catalytic reforming section, and the air inlet direction is parallel to the ground. 2 The flow rate is 100-200mL / min, and the water vapor flow rate is 0.5-2g / min.

[0019] Preferably, when the height of the semi-coke in the cascade pyrolysis device exceeds the edge position below the air inlet of the catalytic reforming section, coke discharge begins, and when the height of the semi-coke in the cascade pyrolysis device is lower than the middle position of the catalytic reforming section, coke discharge stops.

[0020] Preferably, the catalyst loaded in the atmospheric pressure catalytic converter I is a nickel-iron based catalyst with a mixture of ZSM-5 molecular sieve and aluminum smelting waste slag as a carrier.

[0021] Preferably, the method for preparing the nickel-iron based catalyst comprises the following steps:

[0022] (1) Aluminum smelting waste slag is subjected to acidification pretreatment and high-temperature roasting to obtain porous aluminum smelting waste slag;

[0023] (2) mixing porous aluminum smelting waste slag and ZSM-5 molecular sieve in a mass ratio of 4:6 to obtain a composite carrier;

[0024] (3) The composite carrier is added to deionized water, the mass ratio of the composite carrier to deionized water is 1-2:10, and then nickel nitrate and ferric chloride are added, and ultrasonic and stirring are performed at 60-80° C. until the water is completely volatilized, and then the solid mixture is placed at 500-600° C. in air for 1.5-2 hours to obtain a nickel-iron based catalyst, and the mass ratio of nickel nitrate, ferric chloride and the composite carrier is 8:4:100.

[0025] Preferably, the packed compaction density of the catalyst in the atmospheric pressure catalytic converter I is 0.8-1.2 g / cm 3 .

[0026] Preferably, the catalyst loaded in the atmospheric pressure catalytic converter II is a nickel-based catalyst with a carbon molecular sieve as a carrier.

[0027] Preferably, the method for preparing the nickel-based catalyst comprises the following steps:

[0028] (1) Biochar and KOH were mixed evenly in a mass ratio of 1:2, activated at 500-600°C under nitrogen protection for 1-2 h, then heated to 900°C, and CO was introduced while nitrogen was maintained. 2 Activate for 2-4 hours to finally obtain activated carbon, CO 2 The flow rate is 50mL / min;

[0029] (2) The macropores of activated carbon are filled with carbon and deposited by the benzene deposition method to form a multi-level pore carbon molecular sieve;

[0030] (3) adding a multi-level porous carbon molecular sieve to deionized water in a mass ratio of 1-2:10, then adding nickel nitrate, ultrasonicating and stirring at 60-80° C. until the water is completely volatilized, and then calcining at 500-600° C. for 1.5-2 h under nitrogen or inert gas protection to obtain a nickel-based catalyst.

[0031] Preferably, the biomass waste includes one or a combination of two or more of pine sawdust, corn stalks, and poplar wood.

[0032] The present invention has the following beneficial effects:

[0033] (1) Biomass raw materials are fed into the cascade pyrolysis device through a screw feeder. After baking, the carbon content and calorific value of the biomass raw materials increase. Under the action of gravity, the raw materials continue to enter the hot premixing section, pyrolysis gasification section and catalytic reforming section. The temperature of the pyrolysis section is 600-800°C. The semi-coke obtained by pyrolysis is deposited at the bottom by gravity. As the semi-coke accumulates, it can be used as a catalyst for tar conversion to convert part of the tar. O is introduced into the catalytic reforming section. 2 / H 2 O, can reform tar and hydrocarbon gas, release heat, achieve self-sufficient heating, and filter the fly ash caused by pyrolysis

[0034] (2) In the wood waste staged pyrolysis device, tar can be converted by 30-50%, but 50-70% of the tar is still unconverted. The high-temperature pyrolysis gas containing tar is passed into a normal-pressure catalytic converter I. In the converter, a nickel-iron-based catalyst with a mixture of ZSM-5 molecular sieve and aluminum smelting waste slag as a carrier is used to further catalytically convert the tar into high-hydrogen fuel gas. The conversion temperature is 800-1000° C., and the tar conversion rate can reach more than 99%;

[0035] (3) High hydrogen fuel gas still contains a certain amount of CH 4 Hydrocarbon gases, CO 2 The ratio is slightly higher, and it needs to be catalytically reformed in the atmospheric pressure catalytic converter II to finally obtain hydrogen-rich gas, in which the hydrogen content reaches more than 70%.

[0036] (4) The present invention uses cheap aluminum smelting waste slag, pyrolysis semi-coke, and carbon molecular sieve as catalysts through graded and step-by-step thermochemical conversion. The pyrolysis residue catalyzes tar vapor, which significantly reduces the tar yield in the pyrolysis process and increases the hydrogen yield. The aluminum smelting waste slag is coupled with the molecular sieve to catalyze the cracking of tar, thereby improving the effect of cheap nickel-based catalysts on catalytic cracking of tar to produce hydrogen. The carbon molecular sieve is loaded with nickel to catalyze the reforming of hydrocarbon gases, so that the hydrogen ratio reaches more than 70%, thereby achieving the energy and reduction of biomass waste and the harmless and resourceful utilization of aluminum smelting waste slag and pyrolysis residue. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 : It is a structural schematic diagram of a biomass waste segmented pyrolysis catalytic gasification hydrogen production process system provided by the present invention.

[0038] In the figure: 101. baking section, 102. hot premixing section, 103. pyrolysis and gasification section, 104. catalytic reforming section. DETAILED DESCRIPTION

[0039] The present invention is described in detail below with reference to the examples. However, it should be understood that the following examples are only illustrative of the embodiments of the present invention, and are not intended to limit the scope of the present invention.

[0040] The cascade pyrolysis device used in Example 1 of the present invention adopts the wood waste staged pyrolysis catalytic gasification hydrogen production device in Chinese invention patent CN114907869 A. The baking section, heat premixing section, pyrolysis gasification section and catalytic reforming section described in the present invention respectively correspond to the baking section 101, heat premixing section 102, pyrolysis gasification section 103 and catalytic reforming section 104 in the structure of the wood waste staged pyrolysis catalytic gasification hydrogen production device previously patented by the research team of the present invention.

[0041] The atmospheric pressure catalytic converter I and atmospheric pressure catalytic converter II used in Example 1 of the present invention are both atmospheric pressure fixed bed reactors purchased from Suzhou Furande Experimental Equipment Co., Ltd., model FD-BC. During the reaction, the catalyst is loaded in the catalyst loading area in the atmospheric pressure fixed bed reactor, and the loading compaction density is 0.8 g / cm 3 .

[0042] The aluminum smelting waste slag (Huzhou Senge New Materials Co., Ltd.) used in the following Example 1 of the present invention has the composition shown in Table 1:

[0043] Table 1

[0044]

[0045] The catalyst loaded in the atmospheric pressure catalytic converter I in the following Example 1 of the present invention is a nickel-iron based catalyst with a mixture of ZSM-5 molecular sieve and aluminum smelting waste slag as a carrier, and the preparation method is as follows:

[0046] (1) Soaking aluminum smelting waste slag in dilute sulfuric acid with a mass concentration of 30% and stirring the reaction for 4 hours for acidification pretreatment;

[0047] (2) placing the aluminum smelting waste slag after acidification pretreatment in air at 600° C. for 3 hours to obtain porous aluminum smelting waste slag;

[0048] (3) mixing porous aluminum smelting waste slag and ZSM-5 molecular sieve in a mass ratio of 4:6 to obtain a composite carrier;

[0049] (4) The composite carrier is added to deionized water in a mass ratio of 1:10, and then nickel nitrate and ferric chloride are added. The mixture is ultrasonically stirred at 60°C until the water is completely volatilized. The solid mixture is then calcined in air at 550°C for 2 hours to obtain a nickel-iron based catalyst. The mass ratio of nickel nitrate, ferric chloride and the composite carrier is 8:4:100.

[0050] The ZSM-5 molecular sieve used in the following examples of the present invention, model ZSM-5, silicon-aluminum ratio 25, was purchased from the Catalyst Factory of Nankai University.

[0051] The catalyst loaded in the atmospheric pressure catalytic converter II in the following Example 1 of the present invention is a nickel-based catalyst with a carbon molecular sieve as a carrier. The preparation method of the nickel-based catalyst is as follows:

[0052] (1) Biochar and KOH were mixed evenly in a mass ratio of 1:2, activated at 550 °C for 2 h under nitrogen protection, and then heated to 900 °C while nitrogen was introduced. 2 After activation for 2 h, activated carbon was finally obtained. 2 The flow rate is 50mL / min, CO 2 The volume flow ratio with nitrogen is 1:1;

[0053] (2) By the benzene precipitation method, 75 g of activated carbon was placed in a fixed bed at normal pressure, toluene vapor was introduced at a flow rate of 0.5 g / min, and the reaction was carried out at 900° C. for 0.5 h to obtain a multi-level porous carbon molecular sieve;

[0054] (3) adding a multi-level porous carbon molecular sieve into deionized water, wherein the mass ratio of the multi-level carbon molecular sieve to the deionized water is 1:10, and then adding nickel nitrate, ultrasonicating and stirring at 60° C. until the water is completely volatilized, and then calcining at 550° C. for 2 h under nitrogen protection to obtain a nickel-based catalyst.

[0055] The biochar used in the preparation of the nickel-based catalyst was pyrolysis carbon obtained by pyrolyzing pine sawdust at 800°C for 0.5 h under nitrogen protection.

[0056] In the present invention, tar yield = tar amount / biomass waste × 100%.

[0057] The unit of hydrogen content in the following examples of the present invention is expressed in mL / g, which refers to the volume of hydrogen obtained after hydrogen production by staged pyrolysis and catalytic gasification of each gram of biomass.

[0058] Example 1

[0059] A biomass waste staged pyrolysis catalytic gasification hydrogen production process system (the process device structure diagram is as attached to the specification) Figure 1 The steps are as follows:

[0060] (1) Dry the pine sawdust until the moisture content is less than 10% and crush it into 3 mm;

[0061] (2) The crushed biomass waste obtained in step (1) is continuously added as a material into a cascade pyrolysis device through a screw feeder at a feeding rate of 5 kg / h. Under the action of gravity and a premixing and stirring assembly in the cascade pyrolysis device, the material is sequentially processed through a baking section, a heat premixing section, a pyrolysis gasification section, and a catalytic reforming section to obtain semi-coke and volatile matter. The temperatures of the baking section, the heat premixing section, the pyrolysis gasification section, and the catalytic reforming section are 250° C., 500° C., 750° C., and 900° C., respectively. A mixture of pure oxygen and water vapor is continuously introduced into the catalytic reforming section. The air inlet is located in the middle of the catalytic reforming section, and the air inlet direction is parallel to the ground. 2 The flow rate is 100mL / min, the water vapor flow rate is 0.5g / min, when the height of the semi-coke in the cascade pyrolysis device exceeds the edge position below the air inlet of the catalytic reforming section, the coke discharge starts, and when the height of the semi-coke in the cascade pyrolysis device is lower than the middle position of the catalytic reforming section, the coke discharge stops, and the volatile matter is filtered out of the fly ash by the semi-coke accumulated in the catalytic conversion section to obtain high-temperature pyrolysis gas, wherein the high-temperature pyrolysis gas contains 450mL / g of hydrogen, 55mL / g of methane, 100mL / g of carbon dioxide, and 175mL / g of carbon monoxide, and the tar yield is 8%;

[0062] (3) The high-temperature pyrolysis gas is continuously introduced into the atmospheric pressure catalytic converter I through a pipeline, and the tar in the high-temperature cracking gas is catalytically cracked in the atmospheric pressure catalytic converter I, and the reaction temperature is 1000° C. to obtain high-hydrogen fuel gas. The high-hydrogen fuel gas contains 579 ml / g of hydrogen, 33 ml / g of methane, 125 ml / g of carbon dioxide, and 223 ml / g of carbon monoxide, and the tar yield is reduced to 0.1%;

[0063] (4) The high-hydrogen fuel gas obtained in the atmospheric pressure catalytic converter I is continuously introduced into the atmospheric pressure catalytic converter II. The alkane gas in the high-hydrogen fuel gas undergoes catalytic cracking in the atmospheric pressure catalytic converter II to produce hydrogen. The reaction temperature is 800° C. The gas at the bottom of the atmospheric pressure catalytic converter II is collected to obtain hydrogen-rich fuel gas. The hydrogen-rich fuel gas contains 725 ml / g of hydrogen, 10 ml / g of methane, 55 ml / g of carbon dioxide, and 253 ml / g of carbon monoxide.

[0064] Example 2 is the same as Example 1, except that the temperatures in the baking section, hot premixing section, pyrolysis gasification section and catalytic reforming section in Example 2 are 200°C, 300°C, 600°C and 800°C, respectively.

[0065] The high-temperature pyrolysis gas obtained in Example 2 contains 320 mL / g of hydrogen, 105 mL / g of methane, 120 mL / g of carbon dioxide, and 160 mL / g of carbon monoxide;

[0066] The high-hydrogen fuel gas obtained in Example 2 contains 490 mL / g of hydrogen, 65 mL / g of methane, 135 mL / g of carbon dioxide, and 180 mL / g of carbon monoxide, and the tar yield is reduced to 1%;

[0067] The hydrogen-rich fuel gas obtained in Example 2 contains 579 mL / g of hydrogen, 35 mL / g of methane, 95 mL / g of carbon dioxide, and 235 mL / g of carbon monoxide.

[0068] Example 3 is the same as Example 1, except that the temperatures in the baking section, heat premixing section, pyrolysis gasification section and catalytic reforming section in Example 3 are 300°C, 600°C, 800°C and 1000°C, respectively.

[0069] The high-temperature pyrolysis gas obtained in Example 3 contains 420 mL / g of hydrogen, 75 mL / g of methane, 65 mL / g of carbon dioxide, and 185 mL / g of carbon monoxide;

[0070] The high-hydrogen fuel gas obtained in Example 3 contains 510 mL / g of hydrogen, 40 mL / g of methane, 120 mL / g of carbon dioxide, and 220 mL / g of carbon monoxide, and the tar yield is reduced to 0.5%;

[0071] The hydrogen-rich fuel gas obtained in Example 3 contains 710 mL / g of hydrogen, 18 mL / g of methane, 56 mL / g of carbon dioxide, and 265 mL / g of carbon monoxide.

[0072] Example 4 is the same as Example 1, except that the preparation method of the catalyst used in the atmospheric pressure catalytic converter I of Example 4 is as follows:

[0073] (1) Soaking aluminum smelting waste slag in dilute sulfuric acid with a mass concentration of 30% and stirring the reaction for 4 hours for acidification pretreatment;

[0074] (2) placing the aluminum smelting waste slag after acidification pretreatment in air at 600° C. for 3 hours to obtain porous aluminum smelting waste slag;

[0075] (3) mixing porous aluminum smelting waste slag and ZSM-5 molecular sieve in a mass ratio of 4:6 to obtain a composite carrier;

[0076] (4) The composite carrier is added to deionized water in a mass ratio of 1:10, and then nickel nitrate and ferric chloride are added. The mixture is ultrasonically treated and stirred at 60°C until the water is completely volatilized. The solid mixture is then calcined in air at 550°C for 2 hours to obtain a nickel-iron based catalyst. The mass ratio of nickel nitrate, ferric chloride and the composite carrier is 4:1:100.

[0077] The high-temperature pyrolysis gas obtained in Example 4 contains 450 mL / g of hydrogen, 55 mL / g of methane, 100 mL / g of carbon dioxide, and 175 mL / g of carbon monoxide;

[0078] The high-hydrogen fuel gas obtained in Example 4 contains 490 mL / g of hydrogen, 50 mL / g of methane, 115 mL / g of carbon dioxide, and 180 mL / g of carbon monoxide, and the tar yield is reduced to 0.4%;

[0079] The hydrogen-rich fuel gas obtained in Example 4 contains 662 mL / g of hydrogen, 20 mL / g of methane, 85 mL / g of carbon dioxide, and 260 mL / g of carbon monoxide.

[0080] Example 5 is the same as Example 1, except that the preparation method of the catalyst used in the atmospheric pressure catalytic converter I of Example 5 is as follows:

[0081] (1) Soaking aluminum smelting waste slag in dilute sulfuric acid with a mass concentration of 30% and stirring the reaction for 4 hours for acidification pretreatment;

[0082] (2) placing the aluminum smelting waste slag after acidification pretreatment in air at 600° C. for 3 hours to obtain porous aluminum smelting waste slag;

[0083] (3) mixing porous aluminum smelting waste slag and ZSM-5 molecular sieve in a mass ratio of 4:6 to obtain a composite carrier;

[0084] (4) The composite carrier is added to deionized water in a mass ratio of 1:10, and then nickel nitrate and ferric chloride are added. The mixture is ultrasonically stirred at 60°C until the water is completely volatilized. The solid mixture is then calcined in air at 550°C for 2 hours to obtain a nickel-iron based catalyst. The mass ratio of nickel nitrate, ferric chloride and the composite carrier is 6:2:100.

[0085] The high-temperature pyrolysis gas obtained in Example 5 contains 450 mL / g of hydrogen, 55 mL / g of methane, 100 mL / g of carbon dioxide, and 175 mL / g of carbon monoxide;

[0086] The high-hydrogen fuel gas obtained in Example 5 contains 510 mL / g of hydrogen, 35 mL / g of methane, 115 mL / g of carbon dioxide, and 186 mL / g of carbon monoxide, and the tar yield is reduced to 0.4%;

[0087] The hydrogen-rich fuel gas obtained in Example 5 contains 685 mL / g of hydrogen, 12 mL / g of methane, 80 mL / g of carbon dioxide, and 255 mL / g of carbon monoxide.

[0088] Comparative Example 1 is the same as Example 1, except that the catalyst loaded in the atmospheric pressure catalytic converter I in Comparative Example 1 is a nickel-iron based catalyst with ZSM-5 molecular sieve as a carrier, and the preparation method is as follows:

[0089] ZSM-5 molecular sieve is added into deionized water, the mass ratio of ZSM-5 molecular sieve to deionized water is 1:10, then nickel nitrate and ferric chloride are added, ultrasonicated and stirred at 60°C until the water is completely volatilized, and then the solid mixture is calcined in air at 550°C for 2h to obtain a nickel-iron based catalyst, the mass ratio of nickel nitrate, ferric chloride and ZSM-5 molecular sieve is 8:4:100.

[0090] The high-temperature pyrolysis gas obtained in Comparative Example 1 contained 450 mL / g of hydrogen, 55 mL / g of methane, 100 mL / g of carbon dioxide, and 175 mL / g of carbon monoxide;

[0091] The high-hydrogen fuel gas obtained in Comparative Example 1 contained 520 mL / g of hydrogen, 45 mL / g of methane, 125 mL / g of carbon dioxide, and 196 mL / g of carbon monoxide, and the tar yield was reduced to 0.4%;

[0092] The hydrogen-rich fuel gas obtained in Comparative Example 1 contains 679 mL / g of hydrogen, 15 mL / g of methane, 75 mL / g of carbon dioxide, and 265 mL / g of carbon monoxide.

[0093] Comparative Example 2 is the same as Example 1, except that the catalyst used in the atmospheric pressure catalytic converter I of Comparative Example 2 is a nickel-iron based catalyst with aluminum smelting waste slag as a carrier, and the preparation method is as follows:

[0094] (1) Soaking aluminum smelting waste slag in dilute sulfuric acid with a mass concentration of 30% and stirring the reaction for 4 hours for acidification pretreatment;

[0095] (2) placing the aluminum smelting waste slag after acidification pretreatment in air at 600° C. for 3 hours to obtain porous aluminum smelting waste slag;

[0096] (3) Porous aluminum smelting waste slag is added to deionized water, the mass ratio of the porous aluminum smelting waste slag to the deionized water is 1:10, and then nickel nitrate and ferric chloride are added, and ultrasonic and stirring are performed at 60°C until the water is completely volatilized, and then the solid mixture is placed at 550°C in air for 2 hours to obtain a nickel-iron based catalyst, and the mass ratio of nickel nitrate, ferric chloride and porous aluminum smelting waste slag is 8:4:100.

[0097] The high-temperature pyrolysis gas obtained in Comparative Example 2 contained 450 mL / g of hydrogen, 55 mL / g of methane, 100 mL / g of carbon dioxide, and 175 mL / g of carbon monoxide;

[0098] In the high-hydrogen fuel gas obtained in Comparative Example 2, hydrogen was 500 mL / g, methane was 50 mL / g, carbon dioxide was 145 mL / g, and carbon monoxide was 210 mL / g, and the tar yield was reduced to 1%;

[0099] The hydrogen-rich fuel gas obtained in Comparative Example 2 contains 628 mL / g of hydrogen, 25 mL / g of methane, 120 mL / g of carbon dioxide, and 290 mL / g of carbon monoxide.

[0100] Comparative Example 3 is the same as Example 1, except that, when Comparative Example 3 prepares a nickel-iron-based catalyst using a mixture of ZSM-5 molecular sieve and aluminum smelting waste slag as a carrier, step (3) is to mix the porous aluminum smelting waste slag and the ZSM-5 molecular sieve in a mass ratio of 7:3 to obtain a composite carrier.

[0101] The high-temperature pyrolysis gas obtained in Comparative Example 3 contained 450 mL / g of hydrogen, 55 mL / g of methane, 100 mL / g of carbon dioxide, and 175 mL / g of carbon monoxide;

[0102] The high-hydrogen fuel gas obtained in Comparative Example 3 contained 510 mL / g of hydrogen, 45 mL / g of methane, 135 mL / g of carbon dioxide, and 200 mL / g of carbon monoxide, and the tar yield was reduced to 0.6%;

[0103] The hydrogen-rich fuel gas obtained in Comparative Example 3 contains 682 mL / g of hydrogen, 20 mL / g of methane, 115 mL / g of carbon dioxide, and 265 mL / g of carbon monoxide.

[0104] Comparative Example 4 is the same as Example 1, except that, when Comparative Example 4 prepares a nickel-iron-based catalyst using a mixture of ZSM-5 molecular sieve and aluminum smelting waste slag as a carrier, step (3) is to mix the porous aluminum smelting waste slag and the ZSM-5 molecular sieve in a mass ratio of 1:9 to obtain a composite carrier.

[0105] The high-temperature pyrolysis gas obtained in Comparative Example 4 contained 450 mL / g of hydrogen, 55 mL / g of methane, 100 mL / g of carbon dioxide, and 175 mL / g of carbon monoxide;

[0106] The high-hydrogen fuel gas obtained in Comparative Example 4 contained 505 mL / g of hydrogen, 45 mL / g of methane, 130 mL / g of carbon dioxide, and 205 mL / g of carbon monoxide, and the tar yield was reduced to 0.8%;

[0107] The hydrogen-rich fuel gas obtained in Comparative Example 4 contains 665 mL / g of hydrogen, 22 mL / g of methane, 125 mL / g of carbon dioxide, and 280 mL / g of carbon monoxide.

[0108] Comparative Example 5 is the same as Example 1, except that the baking temperature of the biomass waste in Comparative Example 5 is 150°C.

[0109] The high-temperature pyrolysis gas obtained in Comparative Example 5 contained 420 mL / g of hydrogen, 75 mL / g of methane, 110 mL / g of carbon dioxide, and 180 mL / g of carbon monoxide;

[0110] The high-hydrogen fuel gas obtained in Comparative Example 5 contained 520 mL / g of hydrogen, 55 mL / g of methane, 135 mL / g of carbon dioxide, and 200 mL / g of carbon monoxide, and the tar yield was reduced to 0.2%;

[0111] The hydrogen-rich fuel gas obtained in Comparative Example 5 contains 679 mL / g of hydrogen, 20 mL / g of methane, 95 mL / g of carbon dioxide, and 260 mL / g of carbon monoxide.

[0112] Comparative Example 6 is the same as Example 1, except that the catalyst loaded in the atmospheric pressure catalytic converter I of Comparative Example 6 is a nickel-based catalyst with a mixture of ZSM-5 molecular sieve and aluminum smelting waste slag as a carrier, and the preparation method is as follows:

[0113] (1) Soaking aluminum smelting waste slag in dilute sulfuric acid with a mass concentration of 30% and stirring the reaction for 4 hours for acidification pretreatment;

[0114] (2) placing the aluminum smelting waste slag after acidification pretreatment in air at 600° C. for 3 hours to obtain porous aluminum smelting waste slag;

[0115] (3) mixing porous aluminum smelting waste slag and ZSM-5 molecular sieve in a mass ratio of 4:6 to obtain a composite carrier;

[0116] (4) The composite carrier is added to deionized water in a mass ratio of 1:10, and then nickel nitrate is added. The mixture is ultrasonically treated and stirred at 60°C until the water is completely volatilized. The solid mixture is then calcined in air at 550°C for 2 hours to obtain a nickel-based catalyst in a mass ratio of 12:100 to the composite carrier.

[0117] The high-temperature pyrolysis gas obtained in Comparative Example 6 contained 450 mL / g of hydrogen, 55 mL / g of methane, 100 mL / g of carbon dioxide, and 175 mL / g of carbon monoxide;

[0118] The high-hydrogen fuel gas obtained in Comparative Example 6 contained 493 mL / g of hydrogen, 41 mL / g of methane, 120 mL / g of carbon dioxide, and 213 mL / g of carbon monoxide, and the tar yield was reduced to 1%;

[0119] The hydrogen-rich fuel gas obtained in Comparative Example 6 contains 690 mL / g of hydrogen, 18 mL / g of methane, 85 mL / g of carbon dioxide, and 253 mL / g of carbon monoxide.

[0120] Comparative Example 7 is the same as Example 1, except that the catalyst loaded in the atmospheric pressure catalytic converter I of Comparative Example 7 is an iron-based catalyst with a mixture of ZSM-5 molecular sieve and aluminum smelting waste slag as a carrier, and the preparation method is as follows:

[0121] (1) Soaking aluminum smelting waste slag in dilute sulfuric acid with a mass concentration of 30% and stirring the reaction for 4 hours for acidification pretreatment;

[0122] (2) placing the aluminum smelting waste slag after acidification pretreatment in air at 600° C. for 3 hours to obtain porous aluminum smelting waste slag;

[0123] (3) mixing porous aluminum smelting waste slag and ZSM-5 molecular sieve in a mass ratio of 4:6 to obtain a composite carrier;

[0124] (4) The composite carrier is added to deionized water in a mass ratio of 1:10, and then ferric chloride is added. The mixture is ultrasonically treated and stirred at 60°C until the water is completely volatilized. The solid mixture is then calcined in air at 550°C for 2 hours to obtain a nickel-iron-based catalyst in a mass ratio of ferric chloride to the composite carrier of 12:100.

[0125] The high-temperature pyrolysis gas obtained in Comparative Example 7 contained 450 mL / g of hydrogen, 55 mL / g of methane, 100 mL / g of carbon dioxide, and 175 mL / g of carbon monoxide;

[0126] The high-hydrogen fuel gas obtained in Comparative Example 7 contained 460 mL / g of hydrogen, 56 mL / g of methane, 160 mL / g of carbon dioxide, and 166 mL / g of carbon monoxide, and the tar yield was reduced to 2%;

[0127] The hydrogen-rich fuel gas obtained in Comparative Example 7 contains 623 mL / g of hydrogen, 28 mL / g of methane, 105 mL / g of carbon dioxide, and 215 mL / g of carbon monoxide.

[0128] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A biomass waste staged pyrolysis catalytic gasification hydrogen production process system, characterized in that: The following steps are involved: (1) drying and crushing the biomass waste to less than 3 mm; (2) The crushed biomass waste obtained in step (1) is continuously added as a material into a cascade pyrolysis device, and the material is processed in a baking section, a heat premixing section, a pyrolysis gasification section, and a catalytic reforming section under the action of gravity to obtain semi-coke and volatile matter, and the semi-coke is regularly discharged from the bottom of the cascade pyrolysis device, and the volatile matter is filtered out of the semi-coke accumulated in the catalytic conversion section to obtain high-temperature pyrolysis gas after fly ash is removed; (3) continuously introducing the high-temperature pyrolysis gas into a normal-pressure catalytic converter I, so that the tar in the high-temperature cracking gas undergoes catalytic cracking to obtain a high-hydrogen fuel gas; (4) The high-hydrogen fuel gas obtained in the atmospheric pressure catalytic converter I is continuously introduced into the atmospheric pressure catalytic converter II, so that the alkane gas in the high-hydrogen fuel gas undergoes catalytic cracking to produce hydrogen, and hydrogen-rich fuel gas is produced at the bottom of the atmospheric pressure catalytic converter II.

2. A biomass waste staged pyrolysis catalytic gasification hydrogen production process system according to claim 1, characterized in that: The crushed biomass waste obtained in step (1) is added into the cascade pyrolysis device through a screw feeder at a feeding rate of 0.5-5 kg / h.

3. The biomass waste staged pyrolysis catalytic gasification hydrogen production process system according to claim 1 is characterized in that: In step (2), the temperature ranges of the baking section, the heat premixing section, the pyrolysis gasification section and the catalytic reforming section are 250-300°C, 500-600°C, 750-800°C and 900-1000°C respectively.

4. The biomass waste staged pyrolysis catalytic gasification hydrogen production process system according to claim 1 is characterized in that: A mixture of pure oxygen and water vapor is continuously introduced into the catalytic reforming section. The air inlet is located in the middle of the catalytic reforming section, and the air inlet direction is parallel to the ground. The O2 flow rate is 100-200mL / min, and the water vapor flow rate is 0.5-2g / min.

5. The biomass waste staged pyrolysis catalytic gasification hydrogen production process system according to claim 1 is characterized in that: When the height of the semi-coke in the cascade pyrolysis device exceeds the edge position below the air inlet of the catalytic reforming section, coke discharge begins, and when the height of the semi-coke in the cascade pyrolysis device is lower than the middle position of the catalytic reforming section, coke discharge stops.

6. The biomass waste staged pyrolysis catalytic gasification hydrogen production process system according to claim 1 is characterized in that: The catalyst loaded in the atmospheric pressure catalytic converter I is a nickel-iron based catalyst with a mixture of HZSM-5 molecular sieve and aluminum smelting waste slag as a carrier.

7. A biomass waste staged pyrolysis catalytic gasification hydrogen production process system according to claim 6, characterized in that: The preparation method of the nickel-iron based catalyst comprises the following steps: (1) Aluminum smelting waste slag is subjected to acidification pretreatment and high-temperature roasting to obtain porous aluminum smelting waste slag; (2) mixing porous aluminum smelting waste slag and HZSM-5 molecular sieve in a mass ratio of 0-7:3-10 to obtain a composite carrier; (3) Add the composite carrier to deionized water in a mass ratio of 1-10:100, then add nickel nitrate and ferric chloride, ultrasonicate and stir at 60-80°C until the water is completely volatilized, then calcine the solid mixture in air at 500-600°C for 1.5-2h to obtain a nickel-iron based catalyst, in which the mass ratio of nickel nitrate, ferric chloride and the composite carrier is 8:4:

100.

8. The biomass waste staged pyrolysis catalytic gasification hydrogen production process system according to claim 1 is characterized in that: The packed density of the catalyst in the atmospheric pressure catalytic converter I is 0.8-1.2 g / cm 3 .

9. The biomass waste staged pyrolysis catalytic gasification hydrogen production process system according to claim 1, characterized in that: The catalyst loaded in the atmospheric pressure catalytic converter II is a nickel-based catalyst with a carbon molecular sieve as a carrier.

10. A biomass waste staged pyrolysis catalytic gasification hydrogen production process system according to claim 9, characterized in that: The preparation method of the nickel-based catalyst comprises the following steps: (1) Biochar and KOH are uniformly mixed in a mass ratio of 1:0.5-4, chemically activated at 500-600°C under nitrogen protection for 1-2 hours, then heated to 800-1000°C, and CO2 is introduced for physical activation for 2-4 hours while nitrogen is maintained to obtain activated carbon; (2) by a benzene deposition method, toluene vapor is introduced at a flow rate of 0.2-1.5 g / min, and the reaction is carried out at 600-900° C. for 0.5-1.5 h to fill the macropores of the activated carbon with carbonization and deposition to form a multi-level pore carbon molecular sieve; (3) adding a multi-level porous carbon molecular sieve to deionized water in a mass ratio of 1-2:10, then adding nickel nitrate, ultrasonicating and stirring at 60-80° C. until the water is completely volatilized, and then calcining at 500-600° C. for 1.5-2.0 h under nitrogen or inert gas protection to obtain a nickel-based catalyst.

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