Catalyst for hydrogen production from biomass gasification, method for its preparation and method for producing hydrogen
By preparing a core-shell structured bifunctional catalyst, the problems of low hydrogen quality and catalyst deactivation in existing biomass gasification hydrogen production technologies have been solved, achieving efficient and stable hydrogen production and catalyst recycling, thus improving the economics of biomass gasification hydrogen production processes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2022-10-12
- Publication Date
- 2026-06-02
AI Technical Summary
In existing biomass gasification hydrogen production technologies, conventional steam gasification routes produce low-quality hydrogen and have long process flows. Calcium-based absorbents for enhancing gasification routes are limited in large-scale application due to high-temperature deactivation and heat loss. Traditional catalysts are difficult to meet the requirements of rapid gasification processes.
A bifunctional catalyst integrating a calcium-based absorbent and a chemical epoxy support was developed. The core-shell structure catalyst was prepared by a stepwise precipitation and homogeneous composite coating method. Combined with a dual fluidized bed process, the catalyst was reusable and the hydrogen was produced efficiently.
This improved the catalyst's resistance to high-temperature sintering and its CO2 adsorption and desorption performance, reduced hydrogen consumption during the reduction process, and enhanced the economy and hydrogen quality of the biomass hydrogen production process.
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Figure CN117884126B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of biomass energy utilization technology, and specifically relates to a catalyst for biomass gasification to produce hydrogen and a method for producing high-quality hydrogen. Background Technology
[0002] Biomass energy is the only green zero-carbon fuel among renewable energy sources, and its use for hydrogen production has always attracted much attention. However, since the hydrogen content of biomass itself is less than 6%, a significant portion of biomass green hydrogen is obtained through the water-steam shift reaction of biomass carbon. Currently implemented biomass gasification hydrogen production technologies mainly include two types: one is the conventional steam gasification route, and the other is an enhanced gasification hydrogen production route combined with carbon capture. Regarding the conventional gasification route, processes such as dual moving bed, moving bed-fluidized bed, moving bed-gaseous bed, and dual fluidized bed have been developed. Most of these processes first convert biomass into oil and gas and semi-coke through pyrolysis, and then subject the oil and gas and semi-coke to steam reforming and shift reactions. Sometimes, a portion of the oil and gas and semi-coke is burned to meet its own heating needs. Chinese invention patent CN200910116098.6 utilizes a series fluidized bed system to directly combine biomass pyrolysis and oil and gas reforming shift hydrogen production in a steam atmosphere, simplifying the purification process and improving hydrogen yield, but increasing steam consumption and resulting in low overall energy efficiency.
[0003] The biggest problem with conventional steam gasification is that the hydrogen produced by the gasification system is of low quality and difficult to use directly, requiring further processing such as reforming, conversion, and decarbonization. This results in an excessively long process flow, impacting technical and economic efficiency. In contrast, enhanced gasification hydrogen production has three advantages: First, in-situ CO2 absorption shifts the gasification equilibrium towards hydrogen production, significantly increasing hydrogen yield. Second, alkaline CO2 absorbents can simultaneously catalyze the cracking of gasification byproducts (tar and low-carbon hydrocarbons), further improving gas quality. Third, the absorbed CO2 is enriched and recovered through regeneration, facilitating the realization of carbon-negative biomass gasification hydrogen production technology.
[0004] However, currently used high-temperature calcium-based absorbents for CO2 absorption suffer from rapid deactivation due to irreversible shrinkage during adsorption and desorption, while traditional hydration regeneration processes result in significant heat loss, greatly limiting the large-scale application of this technology. Patents CN201811485624.1 and CN201811484040.2 disclose methods for preparing carbonate-resistant calcium-based absorbents using the sol-gel method and impregnation method, respectively, yielding Fe... x O y / CaO-Ca 12 Al 14 O 33The absorbent exhibits more stable cyclic carbonation performance, and its ability to absorb and release CO2 in cycles is improved. However, to suppress CaO sintering caused by high-temperature calcination, the calcium-based absorbent obtained by the above method introduces a large amount of Ca into the CaO microcrystals. 12 Al 14 O 33 This severely affects the CaO adsorption rate, making it difficult to meet the requirements of rapid gasification processes such as biomass fluidized bed hydrogen production. Patent CN201810686624.1 provides a method for preparing a highly cyclically stable calcium-based absorbent with a dual-scale mesoporous structure. The introduced magnesium oxide nanocrystals are uniformly dispersed on the CaO grain boundaries, surface, and pore walls. Although it can maintain its dual-scale mesoporous structure after multiple cycles of calcination / carbonation, the CaO grains exhibit sintering and fusion, accelerating the decline in adsorption performance. Summary of the Invention
[0005] The purpose of this invention is to provide a catalyst for biomass gasification hydrogen production, its preparation method, and a method for producing hydrogen. This invention originally developed a bifunctional catalyst for biomass gasification hydrogen production that integrates a calcium-based absorbent and a chemical epoxy carrier, overcoming the densification problem in the adsorption and desorption process of conventional calcium-based absorbents. Furthermore, through the matching of a dual fluidized bed process, it achieves the dual goals of producing high-quality hydrogen from biomass and recycling the calcium-based absorbent, and has excellent prospects for industrial application.
[0006] To achieve the above objectives, the technical solution of the present invention includes the following aspects:
[0007] I. A method for preparing a catalyst for biomass gasification to hydrogen production is provided, comprising the following steps:
[0008] (1) After mixing doping component A and doping component B evenly, material flow I is obtained;
[0009] (2) Add anionic surfactant and first precipitant to calcium salt solution, adjust the pH of the system to 8-9, and then mix evenly at 40-60℃ to obtain material flow II;
[0010] (3) Add the material flow I, the second precipitant and the third precipitant obtained in step (1) to the material flow II obtained in step (2), mix them evenly at 70-80°C to obtain material flow III, and then obtain the catalyst after further heat treatment.
[0011] II. The present invention provides a catalyst for biomass gasification to produce hydrogen, wherein the catalyst is obtained by the above preparation method.
[0012] III. This invention provides a method for producing hydrogen from biomass gasification, comprising the following steps:
[0013] (a) The pretreated biomass feedstock enters the gasification reactor, where hydrogen and gasified coke residue are generated under the combined action of fluidizing air and catalyst;
[0014] (b) The catalyst to be regenerated after the reaction and the gasified coke residue enter the riser regenerator under the action of the feed air, and the catalyst to be regenerated is regenerated by oxidation and combustion, and high temperature flue gas I is generated.
[0015] (c) The regenerated catalyst is sent to the primary return feeder after gas-solid separation. It is activated by high-temperature flue gas I. The activated catalyst is then returned to the gasification reactor for recycling after further gas-solid separation.
[0016] As described above, compared with the prior art, the present invention has the following beneficial effects:
[0017] 1) The biomass gasification hydrogen production catalyst provided by this invention has a core-shell structure. The core is calcium oxide, and the outer shell is composed of calcium oxide, an oxide of dopant component A, and an oxide of dopant component B. The calcium oxide and the oxide of dopant component A form a stable composite oxide, enhancing the high-temperature sintering resistance of the calcium oxide. The oxide of dopant component A can also uniformly disperse the oxide of dopant component B, improving the catalyst's cracking performance. Furthermore, due to the introduction of dopant component B, the core-shell structured catalyst can simultaneously release water vapor and carbon dioxide in a reduced state while maintaining the porous structure of the shell. This facilitates the rapid adsorption and desorption of CO2 by the catalyst, promoting the stability and recyclability of the biomass hydrogen production catalyst.
[0018] 2) The preparation method of the biomass gasification hydrogen production catalyst provided by this invention employs a hierarchical precipitation and homogeneous composite coating method. First, by adjusting the pH, some calcium is precipitated from its salt solution and self-assembled into a nanoscale precursor core under the action of anionic surfactant. Then, dopant component A, dopant component B, and the remaining calcium are distributed around the precursor core through complexation with the anionic surfactant. Further, by using a combination of various precipitants, dopant component A, dopant component B, and the remaining calcium are simultaneously precipitated from the solution system and uniformly distributed on the surface of the precursor core. After heat treatment, a catalyst with a calcium oxide core and a composite coated shell is prepared. Compared with existing conventional composite calcium-based catalysts, the dopant component in the catalyst of this invention is more distributed on the catalyst surface shell, overcoming the ineffective distribution of the dopant component in the core, significantly reducing the amount of dopant component used, and simultaneously improving the catalyst's CO2 adsorption capacity.
[0019] 3) Based on its rapid reaction characteristics and stable recycling performance, the biomass gasification hydrogen production catalyst of this invention has been successfully applied in the biomass dual fluidized bed gasification hydrogen production process. The stable recycling of the biomass gasification hydrogen production catalyst is achieved through three processes: catalytic gasification of biomass, catalyst oxidation regeneration, and catalyst activation. In particular, the catalyst regeneration process adopts an oxygen-deficient multi-stage combustion method to obtain CO-rich flue gas. The CO contained in the regenerated flue gas is further used to reduce and activate the dopant component B in the catalyst, which greatly reduces the consumption of hydrogen in the catalyst reduction process and helps to improve the economic efficiency of the biomass hydrogen production process. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the method and system for producing hydrogen from biomass gasification according to the present invention.
[0021] Among them, 1-bubbling bed gasification reactor; 2-feeder; 3-riser regenerator; 4-first-stage gas-solid separator; 5-first-stage return feeder; 6-second-stage gas-solid separator; 7-second-stage return feeder. Detailed Implementation
[0022] To achieve the above objectives, the technical solution of the present invention includes the following aspects:
[0023] I. A method for preparing a catalyst for biomass gasification to hydrogen production is provided, comprising the following steps:
[0024] (1) After mixing doping component A and doping component B evenly, material flow I is obtained;
[0025] (2) Add anionic surfactant and first precipitant to calcium salt solution, adjust the pH of the system to 8-9, and then mix evenly at 40-60℃ to obtain material flow II;
[0026] (3) Add the material flow I, the second precipitant and the third precipitant obtained in step (1) to the material flow II obtained in step (2), mix them evenly at 70-80°C to obtain material flow III, and then obtain the catalyst after further heat treatment.
[0027] Preferably, in the preparation method of the catalyst for biomass gasification hydrogen production, the dopant component A is a metal-soluble salt, wherein the metal element is one or more elements from Group IIIA and Group IVB, such as one or more elements from aluminum, boron, zirconium, and titanium; specifically, dopant component A can be selected from one or more soluble salts containing aluminum, boron, zirconium, and titanium, preferably aluminum salts and / or zirconium salts; under more preferred conditions, dopant component A is one or more elements from aluminum nitrate, aluminum sulfate, aluminum chloride, zirconium nitrate, and zirconium oxychloride. Furthermore, the molar concentration of dopant component A in the solution is 0.5–1 mol / L.
[0028] Preferably, in the preparation method of the catalyst for biomass gasification hydrogen production, the dopant component B is a metal-soluble salt, wherein the metal element is one or more of Group IB, Group VIIB, and Group VIII lanthanides, such as nickel, iron, cobalt, copper, manganese, cerium, and lanthanum; the dopant component B can be selected from one or more combinations of soluble salts containing elements such as nickel, iron, cobalt, copper, manganese, cerium, and lanthanum; under more preferred conditions, the dopant component B is one or more of nickel nitrate, iron nitrate, and manganese nitrate. Furthermore, the molar concentration of the dopant component B solution is 0.5–1 mol / L.
[0029] Preferably, in the preparation method of the catalyst for biomass gasification hydrogen production, the calcium salt can be selected from at least one of calcium nitrate, calcium chloride, calcium iodide, calcium pyruvate, calcium nitrite, calcium formate, calcium acetate, calcium propionate, and calcium dodecylbenzenesulfonate, preferably calcium nitrate. Furthermore, the molar concentration of the calcium salt solution is 0.1–1 mol / L.
[0030] Preferably, in the preparation method of the catalyst for biomass gasification hydrogen production, the anionic surfactant can be one or more of the following: fatty acid salts with 15 to 33 carbon atoms, sulfonates with 12 to 20 carbon atoms, and sulfates with 10 to 18 carbon atoms; the molar concentration of the anionic surfactant solution is 0.02 to 0.2 mol / L.
[0031] Preferably, in the method for preparing the catalyst for biomass gasification hydrogen production, the fatty acid salts with 15 to 33 carbon atoms include soaps and / or N-alkyl acyl polypeptides; the sulfonates with 12 to 20 carbon atoms include one or more of alkylbenzene sulfonates, α-olefin sulfonates, alkyl sulfonates, α-sulfonyl monocarboxylic acids, fatty acid sulfonyl esters, succinate sulfonates, alkylnaphthalene sulfonates, petroleum sulfonates, lignin sulfonates, and alkyl glycerol ether sulfonates; and the sulfates with 10 to 18 carbon atoms include fatty alcohol sulfates and / or secondary alkyl sulfates.
[0032] Preferably, in the preparation method of the catalyst for biomass gasification hydrogen production, the anionic surfactant includes at least one of sodium dodecyl sulfate, sodium hexadecyl sulfonate, sodium dodecylbenzene sulfonate, and sodium lauryl ether sulfate.
[0033] Preferably, in the preparation method of the catalyst for biomass gasification hydrogen production, the first precipitant is an alkaline amino-containing compound, specifically selected from at least one of ammonia, urea, thiourea, biuret, triuret, methylamine, ethylamine, ethanolamine, ethylenediamine, propylamine, isopropylamine, propylenediamine, dimethylamine, trimethylamine, triethylamine, and aliphatic amines (C8-C10), preferably at least one of ammonia, urea, and ethanolamine. Furthermore, the molar concentration of the first precipitant solution is 1-15 mol / L.
[0034] Preferably, in the preparation method of the catalyst for biomass gasification hydrogen production, the second precipitant is at least one selected from oxalate, citrate, succinate, and malate. Specifically, oxalate can be selected from at least one selected from ammonium oxalate, sodium oxalate, and potassium oxalate; citrate can be selected from at least one selected from ammonium citrate, sodium citrate, and potassium citrate; succinate can be selected from at least one selected from ammonium succinate, sodium succinate, and potassium succinate; and malate can be selected from at least one selected from ammonium malate, sodium malate, and potassium malate. Furthermore, the molar concentration of the second precipitant solution is 0.1–0.5 mol / L.
[0035] Preferably, in the method for preparing the catalyst for biomass gasification hydrogen production, the third precipitant is a carbonate, which may be selected from at least one of ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate. Furthermore, the molar concentration of the third precipitant solution is 0.1–0.5 mol / L.
[0036] Preferably, in the preparation method of the catalyst for biomass gasification hydrogen production, the molar ratio of calcium salt, dopant component A, and dopant component B is 10:0.1 to 1:0.05 to 0.5, based on the molar ratio of metal elements.
[0037] Preferably, in the preparation method of the catalyst for biomass gasification to hydrogen production, the molar ratio of the second precipitant to the dopant component B, based on acid anions and metal cations respectively, is 1:0.5 to 1.
[0038] Preferably, in the preparation method of the catalyst for biomass gasification to hydrogen production, the molar ratio of the third precipitant to the dopant component A, based on acid anions and metal cations respectively, is 1:0.4 to 0.8.
[0039] Preferably, in the preparation method of the catalyst for biomass gasification to produce hydrogen, when adding the anionic surfactant and the first precipitant in step (2), the anionic surfactant and the first precipitant are added slowly, specifically by dripping, with the dripping rate controlled at 0.1 to 1 mL / min.
[0040] Preferably, in the preparation method of the catalyst for biomass gasification to produce hydrogen, when adding the feed stream I, the second precipitant and the third precipitant obtained in step (1) in step (3), the addition is slow, specifically by dripping, with the dripping speed controlled at 0.1 to 1 ml / min; preferably, the feed stream I, the second precipitant and the third precipitant obtained in step (1) are added by simultaneous dripping of three streams.
[0041] Preferably, in the preparation method of the catalyst for biomass gasification hydrogen production, the heat treatment in step (3) includes drying heat treatment and calcination heat treatment, wherein the drying heat treatment temperature is 105-140℃ and the drying heat treatment time is 4-6 hours; the calcination heat treatment temperature is 800-900℃ and the calcination heat treatment time is 1-4 hours.
[0042] Preferably, in the preparation method of the catalyst for biomass gasification hydrogen production, the catalyst obtained in step (3) is further subjected to molding treatment. The molding process can be any of the existing molding methods in the art. The catalyst shape can be any shape such as strip or sphere. Specifically, in the present invention, the molding treatment can first grind the catalyst into fine powder, and then use centrifugal granulation to obtain micro spherical catalysts of 0.2 to 2 mm.
[0043] Preferably, in the method for preparing the catalyst for biomass gasification to hydrogen production, the step of forming the microspherical catalyst is as follows:
[0044] S1: First, the catalyst powder and dispersant are mixed to obtain a mixture;
[0045] S2: A portion of the mixture obtained in step S1 is added to a centrifugal granulator as a base material for granulation. During the granulation process, a binder solution is continuously sprayed in. After the mixture becomes small particles, the remaining mixture and binder solution are sprayed in simultaneously until the required microsphere catalyst is obtained.
[0046] In the above method, the dispersant may be selected from one or more of polyethylene glycol 200, polyethylene glycol 400, polyacrylamide, maleic acid copolymer, polycarboxylate, polyvinylpyrrolidone, and potassium sorbate; the mass ratio of the dispersant to the mixture is 0.01 to 0.05:1.
[0047] In the above method, the binder can be selected from one or more of microcrystalline cellulose, hydroxypropyl methylcellulose, polyvinyl alcohol, cyclodextrin, guar gum powder, starch, aluminum sol, nitric acid, and citric acid; the mass ratio of binder to mixture is 0.05 to 0.2:1, and the molar concentration of binder solution is 0.01 to 0.1 mol / L.
[0048] Furthermore, the operating conditions for preparing the above-mentioned bifunctional catalyst microspheres are as follows: the atomizing disc speed of the centrifugal granulator is 100-800 rpm, the inlet air speed is controlled at 400-1000 rpm, the inlet air temperature is controlled at 40-80℃, the exhaust air speed is controlled at 200-500 rpm, and the peristaltic pump used for spraying in the mixture and binder has a spray speed of 20-150 rpm.
[0049] II. This invention provides a catalyst for biomass gasification to produce hydrogen, which is obtained by the above-described preparation method. The catalyst for biomass gasification to produce hydrogen comprises a calcium oxide matrix, an oxide of dopant component A, and an oxide of dopant component B. Based on the mass percentage of the composition, the calcium oxide matrix accounts for 80-90%, the oxide of dopant component A accounts for 5-15%, and the oxide of dopant component B accounts for 2-10%.
[0050] III. This invention provides a method for producing hydrogen from biomass gasification, comprising the following steps:
[0051] (a) The pretreated biomass feedstock enters the gasification reactor, where hydrogen and gasified coke residue are generated under the combined action of fluidizing air and catalyst;
[0052] (b) The catalyst to be regenerated after the reaction and the gasified coke residue enter the riser regenerator under the action of the feed air, and the catalyst to be regenerated is regenerated by oxidation and combustion, and high temperature flue gas I is generated.
[0053] (c) The regenerated catalyst is sent to the primary return feeder after gas-solid separation. It is activated by high-temperature flue gas I. The activated catalyst is then returned to the gasification reactor for recycling after further gas-solid separation.
[0054] Preferably, in the method for producing hydrogen from biomass gasification, the fluidizing air in step (a) can be one or more of water vapor, a mixture of water vapor and oxygen, preferably a mixture of water vapor and oxygen, wherein the volume ratio of water vapor to oxygen in the mixture is 1:0.01 to 0.1; under normal operating conditions, the flow rate of the fluidizing air is 5 to 20 m / s.
[0055] Preferably, in the method for producing hydrogen by biomass gasification, the operating conditions of the gasification reactor in step (a) are: temperature 620-720℃, reaction time 10-30s.
[0056] Preferably, in the method for producing hydrogen by biomass gasification, the mass ratio of biomass feedstock to catalyst in step (a) is 1:5 to 10.
[0057] Preferably, in the method for producing hydrogen from biomass gasification, the biomass raw material in step (a) can be derived from any material containing lignocellulose, such as corn stalks, rice husks, wheat straw, wood blocks, leaves, and branches. For biomass raw materials with low density such as straw that require molding, the pretreatment process includes drying, crushing, and molding. The specific processing conditions are as follows: the dried biomass is directly crushed to below 2mm and then physically extruded under 10-20MPa conditions to obtain biomass raw materials with a size of 9-20mm. For biomass raw materials with high density such as wood blocks that do not require molding, biomass raw materials with a size close to the molding size are directly obtained by cutting or other methods.
[0058] Preferably, in the method for producing hydrogen from biomass gasification, the feed air in step (b) can be water vapor, a mixture of water vapor and carrier gas, wherein the carrier gas is at least one of nitrogen, oxygen, and air, preferably a mixture of water vapor and air, wherein the volume ratio of water vapor to carrier gas is 1:0.05 to 0.2. Under normal operating conditions, the flow rate of the feed air is 1 to 5 m / s.
[0059] Preferably, in the method for producing hydrogen from biomass gasification, the regeneration conditions of the riser regenerator in step (b) are: regeneration temperature of 850-950°C, regeneration time of 5-10s, and regeneration atmosphere of air. In order to reduce the dilution effect of air on flue gas, it is preferred to use an oxygen-deficient combustion method. The specific operation includes multi-stage combustion regeneration, with a first-stage air velocity of 20-50m / s and a second-stage air velocity of 10-20m / s. The high-temperature flue gas I generated by the above operation has a CO2 volume content of more than 25% and a CO volume content of 5-10%.
[0060] Preferably, in the method for producing hydrogen from biomass gasification, the catalyst pore-forming activation conditions in step (c) are as follows: temperature is 850-900℃, activation time is 1-5 min, and flow rate of high-temperature flue gas I is 1-5 m / s. The activation reaction utilizes CO in high-temperature flue gas I to reduce the dopant component B in the catalyst. The released CO2 can alleviate the loss of pore structure in the calcium-based support due to regeneration and densification, thereby stabilizing the adsorption performance. At the same time, the reduced dopant component B can further crack the tar and low-carbon hydrocarbon molecules in the biomass hydrogen production process, thereby obtaining a higher concentration of hydrogen product.
[0061] Preferably, in the method for producing hydrogen from biomass gasification, the concentration of the hydrogen product obtained in step (c) can reach more than 75%, and the tar content carried by the hydrogen is less than 5 mg / Nm³. 3 Ash content not exceeding 10 mg / Nm 3 The hydrogen yield throughout the process is no less than 80g / kg dry biomass.
[0062] Example 1
[0063] Calcium nitrate, aluminum nitrate, and nickel nitrate were prepared into solutions with concentrations of 0.5 mol / L, 0.5 mol / L, and 0.5 mol / L, respectively. These solutions were weighed according to a metal element molar ratio of 10:0.1:0.05. Aluminum nitrate and nickel nitrate were thoroughly mixed to form feed stream I, which was then set aside. 0.02 mol / L sodium hexadecyl sulfonate and 1 mol / L ammonia were added dropwise to the calcium nitrate solution to adjust the pH to 8. The mixture was then continuously stirred at 60°C until a nanoemulsion was formed, yielding feed stream II. Feed stream I, 0.1 mol / L ammonium oxalate, and 0.1 mol / L ammonium bicarbonate were then added dropwise to feed stream II in three separate steps. The mixture was continuously stirred at 80°C to obtain feed stream III. Feed stream III was dried at 105°C for 6 hours, calcined at 900°C for 1 hour, and ground into a fine powder to obtain the catalyst powder.
[0064] The catalyst powder was mixed with polyethylene glycol 200 at a mass ratio of 1:0.01. Then, 50% of the total weight of the mixture was added as a base material to a centrifugal granulator for granulation. The granulation conditions were as follows: atomizing disc speed of 400 rpm, inlet air speed of 400 rpm, inlet air temperature of 40℃, exhaust air speed of 200 rpm, and peristaltic pump injection speed of 20 rpm. During the granulation process, a 0.01 mol / L hydroxypropyl methylcellulose solution was continuously sprayed. After the mixture became small particles, the remaining mixture and hydroxypropyl methylcellulose solution were added. The hydroxypropyl methylcellulose and the mixed powder were added at a mass ratio of 0.05:1, causing the small particles to gradually enlarge into microspheres, thus obtaining 1 mm catalyst microspheres SDCCa-1.
[0065] Example 2
[0066] Calcium nitrate, aluminum nitrate, and nickel nitrate were prepared into solutions with concentrations of 1 mol / L, 0.5 mol / L, and 0.5 mol / L, respectively. These solutions were weighed according to a metal element molar ratio of 10:0.5:0.2. Aluminum nitrate and nickel nitrate were thoroughly mixed to form feed stream I, which was then set aside. 0.1 mol / L sodium dodecyl sulfate and 5 mol / L ammonia were added dropwise to the calcium nitrate solution, and the pH was adjusted to 9. The mixture was then continuously stirred at 40°C until a nanoemulsion was formed, yielding feed stream II. Feed stream I, 0.2 mol / L ammonium citrate, and 0.2 mol / L ammonium carbonate were then added dropwise to feed stream II in three separate steps. The mixture was continuously stirred at 60°C to obtain feed stream III. Feed stream III was dried at 105°C for 6 hours, calcined at 800°C for 4 hours, and ground into a fine powder to obtain the catalyst powder.
[0067] The catalyst powder was mixed with polyvinylpyrrolidone at a mass ratio of 1:0.02. Then, 50% of the total weight of the mixture was added as a base material to a centrifugal granulator for granulation. The granulation conditions were as follows: atomizing disc speed of 600 rpm, inlet air speed of 800 rpm, inlet air temperature of 60℃, exhaust air speed of 400 rpm, and peristaltic pump injection speed of 80 rpm. During the granulation process, a 0.05 mol / L guar gum powder solution was continuously sprayed in. After the mixture became small particles, the remaining mixture and guar gum powder solution were added. The guar gum powder and the mixed powder were added at a mass ratio of 0.1:1, causing the small particles to gradually enlarge into microspheres, thus obtaining 0.5 mm catalyst microspheres SDCCa-2.
[0068] Example 3
[0069] Calcium nitrate, aluminum nitrate, and nickel nitrate were prepared into solutions with concentrations of 1 mol / L, 1 mol / L, and 1 mol / L, respectively. These solutions were weighed according to a metal element molar ratio of 10:1:0.5. Aluminum nitrate and nickel nitrate were thoroughly mixed to form feed stream I, which was set aside. 0.2 mol / L sodium dodecyl sulfate and 15 mol / L ammonia were added dropwise to the calcium nitrate solution, and the pH was adjusted to 9. The mixture was then continuously stirred at 40°C until a nanoemulsion was formed, yielding feed stream II. Feed stream I, 0.5 mol / L ammonium citrate, and 0.5 mol / L ammonium bicarbonate were then added dropwise to feed stream II in three separate steps. The mixture was continuously stirred at 60°C to obtain feed stream III. Feed stream III was dried at 140°C for 4 hours, calcined at 800°C for 4 hours, and ground into a fine powder to obtain the catalyst powder.
[0070] The catalyst powder was mixed with polyvinylpyrrolidone at a mass ratio of 1:0.05. Then, 50% of the total weight of the mixture was added as a base material to a centrifugal granulator for granulation. The granulation conditions were as follows: atomizing disc speed of 200 rpm, inlet air speed of 400 rpm, inlet air temperature of 60℃, exhaust air speed of 200 rpm, and peristaltic pump injection speed of 40 rpm. During the granulation process, a 0.1 mol / L aluminum sol solution was continuously sprayed. After the mixture became small particles, the remaining mixture and aluminum sol solution were added. The aluminum sol and mixed powder were added at a mass ratio of 0.2:1, causing the small particles to gradually enlarge into microspheres, thus obtaining 2 mm catalyst microspheres SDCCa-3.
[0071] Example 4
[0072] Calcium nitrate, aluminum nitrate, and nickel nitrate were prepared into solutions with concentrations of 0.5 mol / L, 0.5 mol / L, and 0.5 mol / L, respectively. These solutions were weighed according to a metal element molar ratio of 10:0.6:0.3. Aluminum nitrate and nickel nitrate were thoroughly mixed to form feed stream I, which was set aside. 0.1 mol / L sodium dodecyl sulfate and 5 mol / L ammonia were added dropwise to the calcium nitrate solution, and the pH was adjusted to 8. The mixture was then continuously stirred at 40°C until a nanoemulsion was formed, yielding feed stream II. Feed stream I, 0.2 mol / L ammonium citrate, and 0.2 mol / L ammonium bicarbonate were then added dropwise to feed stream II in three separate steps. The mixture was continuously stirred at 60°C to obtain feed stream III. Feed stream III was dried at 105°C for 6 hours, calcined at 800°C for 4 hours, and ground into a fine powder to obtain the catalyst powder.
[0073] The catalyst powder was mixed with polyvinylpyrrolidone at a mass ratio of 1:0.04. Then, 50% of the total weight of the mixture was added as a base material to a centrifugal granulator for granulation. The granulation conditions were as follows: atomizing disc speed of 800 rpm, inlet air speed of 600 rpm, inlet air temperature of 80℃, exhaust air speed of 400 rpm, and peristaltic pump injection speed of 100 rpm. During the granulation process, a 0.05 mol / L guar gum powder solution was continuously sprayed in. After the mixture became small particles, the remaining mixture and guar gum powder solution were added. The guar gum powder and the mixed powder were added at a mass ratio of 0.1:1, causing the small particles to gradually enlarge into microspheres, thus obtaining 0.2 mm catalyst microspheres SDCCa-4.
[0074] Example 5
[0075] Calcium nitrate, zirconium nitrate, and nickel nitrate were prepared into solutions with concentrations of 0.5 mol / L, 0.5 mol / L, and 0.5 mol / L, respectively. These solutions were weighed according to a metal element molar ratio of 10:1:0.5. Zirconium nitrate and nickel nitrate were thoroughly mixed to form feed stream I, which was set aside. 0.1 mol / L sodium dodecyl sulfate and 5 mol / L ammonia were added dropwise to the calcium nitrate solution, and the pH was adjusted to 8. The mixture was then continuously stirred at 40°C until a nanoemulsion was formed, yielding feed stream II. Feed stream I, 0.2 mol / L ammonium citrate, and 0.2 mol / L ammonium bicarbonate were then added dropwise to feed stream II in three separate steps. The mixture was continuously stirred at 60°C to obtain feed stream III. Feed stream III was dried at 105°C for 6 hours, calcined at 800°C for 4 hours, and ground into a fine powder to obtain the catalyst powder.
[0076] The catalyst powder was mixed with polyvinylpyrrolidone at a mass ratio of 1:0.04. Then, 50% of the total weight of the mixture was added as a base material to a centrifugal granulator for granulation. The granulation conditions were as follows: atomizing disc speed of 800 rpm, inlet air speed of 600 rpm, inlet air temperature of 80℃, exhaust air speed of 400 rpm, and peristaltic pump injection speed of 100 rpm. During the granulation process, a 0.05 mol / L guar gum powder solution was continuously sprayed in. After the mixture became small particles, the remaining mixture and guar gum powder solution were added. The guar gum powder and the mixed powder were added at a mass ratio of 0.1:1, causing the small particles to gradually enlarge into microspheres, thus obtaining 0.2 mm catalyst microspheres SDCCa-5.
[0077] Example 6
[0078] Calcium nitrate, zirconium nitrate, and manganese nitrate were prepared into solutions with concentrations of 0.5 mol / L, 0.5 mol / L, and 0.5 mol / L, respectively. These solutions were weighed according to a metal element molar ratio of 10:0.5:0.3. Zirconium nitrate and nickel nitrate were thoroughly mixed to form feed stream I, which was set aside. 0.1 mol / L sodium dodecyl sulfate and 5 mol / L ammonia were added dropwise to the calcium nitrate solution, and the pH was adjusted to 8. The mixture was then continuously stirred at 40°C until a nanoemulsion was formed, yielding feed stream II. Feed stream I, 0.2 mol / L ammonium citrate, and 0.2 mol / L ammonium bicarbonate were then added dropwise to feed stream II in three separate steps. The mixture was continuously stirred at 60°C to obtain feed stream III. Feed stream III was dried at 105°C for 6 hours, calcined at 800°C for 4 hours, and ground into a fine powder to obtain the catalyst powder.
[0079] The catalyst powder was mixed with polyvinylpyrrolidone at a mass ratio of 1:0.04. Then, 50% of the total weight of the mixture was added as a base material to a centrifugal granulator for granulation. The granulation conditions were as follows: atomizing disc speed of 800 rpm, inlet air speed of 600 rpm, inlet air temperature of 80℃, exhaust air speed of 400 rpm, and peristaltic pump injection speed of 100 rpm. During the granulation process, a 0.05 mol / L guar gum powder solution was continuously sprayed in. After the mixture became small particles, the remaining mixture and guar gum powder solution were added. The guar gum powder and the mixed powder were added at a mass ratio of 0.1:1, causing the small particles to gradually enlarge into microspheres, thus obtaining 0.2 mm catalyst microspheres SDCCa-6.
[0080] Example 7
[0081] Pretreated 12mm biomass feedstock and catalyst microspheres SDCCa-1 were mixed at a mass ratio of 1:10 and fed into fluidized bed gasification reactor 1. Under fluidization conditions of a mixed gas (water vapor to oxygen volume ratio of 1:0.05) at a flow rate of 10 m / s, heat and mass transfer occurred between the feedstock and SDCCa-1. The gasification reaction was carried out at 620℃ for 15 s, producing high-quality hydrogen product with a hydrogen concentration of 82% and a tar content of 10 mg / Nm³. 3 The ash content is 45 mg / Nm³. 3 The entire process achieves a hydrogen yield of 105 g / kg dry biomass. After gasification, SDCCa-1 and gasified coke residue are fed from feeder 2 into riser regenerator 3 under the action of a feed air flow of 2 m / s (water vapor to air volume ratio of 1:0.1). Two-stage oxygen-deficient combustion regeneration is performed at 900℃, with the first stage air flow rate at 30 m / s and the second stage at 12 m / s, for a regeneration time of 6 s, yielding regenerated SDCCa-1. Simultaneously, high-temperature CO2-rich flue gas I is generated, with a CO2 content of 30% and a CO content of 6%. The regenerated SDCCa-1 is then fed into a primary gas-solid separator 4 and a primary return feeder 5, where it is activated for 5 minutes at 900℃ under the action of high-temperature flue gas I at a flow rate of 2 m / s. The activated SDCCa-1 then undergoes a secondary gas-solid separator 6 and a secondary return feeder 7 for recycling.
[0082] Example 8
[0083] Pretreated 9mm biomass feedstock and catalyst microspheres SDCCa-2 were mixed at a mass ratio of 1:5 and fed into fluidized bed gasification reactor 1. Under fluidization conditions of a mixed gas (water vapor and oxygen volume ratio of 1:0.1) at a flow rate of 5 m / s, heat and mass transfer occurred between the feedstock and SDCCa-2. The gasification reaction was carried out at 720℃ for 30 s, producing high-quality hydrogen product with a hydrogen concentration of 75% and a tar content of 15 mg / Nm³. 3 The ash content is 40 mg / Nm³. 3The entire process achieves a hydrogen yield of 92 g / kg dry biomass. After gasification, SDCCa-2 and gasified coke residue are fed from feeder 2 into riser regenerator 3 under the action of a 5 m / s feed air flow (water vapor to air volume ratio of 1:0.05). Two-stage oxygen-deficient combustion regeneration is performed at 850℃, with a first-stage air flow rate of 20 m / s and a second-stage air flow rate of 10 m / s, for a regeneration time of 10 s, yielding regenerated SDCCa-2. Simultaneously, high-temperature CO2-rich flue gas I is generated, with a CO2 content of 26% and a CO content of 10%. The regenerated SDCCa-2 is then fed into a first-stage return feeder 5 via a first-stage gas-solid separator 4. Under the action of high-temperature flue gas I at a flow rate of 5 m / s, it is activated at 900℃ for 5 minutes. The activated SDCCa-2 then undergoes a second-stage gas-solid separator 6 and a second-stage return feeder 7 for recycling.
[0084] Example 9
[0085] Pretreated 20mm biomass feedstock and catalyst microspheres SDCCa-3 were mixed at a mass ratio of 1:10 and fed into fluidized bed gasification reactor 1. Under fluidization conditions of a mixed gas (water vapor and oxygen volume ratio of 1:0.1) at a flow rate of 20 m / s, heat and mass transfer occurred between the feedstock and SDCCa-3. The gasification reaction was carried out at 720℃ for 10 s, producing high-quality hydrogen product with a hydrogen concentration of 70% and a tar content of 20 mg / Nm³. 3 The ash content is 50 mg / Nm³. 3 The entire process achieves a hydrogen yield of 80 g / kg dry biomass. After gasification, SDCCa-3 and gasified coke residue are fed from feeder 2 into riser regenerator 3 under the action of a feed air flow of 5 m / s (water vapor to air volume ratio of 1:0.2). Two-stage oxygen-deficient combustion regeneration is performed at 950℃, with the first stage air flow rate at 50 m / s and the second stage at 20 m / s, for a regeneration time of 5 seconds, yielding regenerated SDCCa-3. Simultaneously, high-temperature CO2-rich flue gas I is generated, with a CO2 content of 35% and a CO content of 3%. The regenerated SDCCa-3 is then fed into a primary gas-solid separator 4 and a primary return feeder 5. Under the action of high-temperature flue gas I at a flow rate of 5 m / s, it is activated at 850℃ for 5 minutes. The activated SDCCa-3 then undergoes a secondary gas-solid separator 6 and a secondary return feeder 7 for recycling.
[0086] Example 10
[0087] Pretreated 9mm biomass feedstock and catalyst microspheres SDCCa-4 were mixed at a mass ratio of 1:10 and fed into fluidized bed gasification reactor 1. Under fluidization conditions of a mixed gas (water vapor and oxygen volume ratio of 1:0.01) at a flow rate of 6 m / s, heat and mass transfer occurred between the feedstock and SDCCa-4. The gasification reaction was carried out at 660℃ for 30 s, producing high-quality hydrogen product with a hydrogen concentration of 87% and a tar content of 8 mg / Nm³. 3 The ash content is 40 mg / Nm³. 3 The entire process achieves a hydrogen yield of 118 g / kg dry-based biomass. After gasification, SDCCa-4 and gasified coke residue are fed from feeder 2 into riser regenerator 3 under the action of a 1 m / s feed air flow (water vapor to air volume ratio of 1:0.05). Two-stage oxygen-deficient combustion regeneration is performed at 900℃, with a first-stage air flow rate of 20 m / s and a second-stage air flow rate of 10 m / s, for a regeneration time of 10 s, yielding regenerated SDCCa-4. Simultaneously, high-temperature CO2-rich flue gas I is generated, with a CO2 content of 25% and a CO content of 12%. The regenerated SDCCa-4 is then fed into a first-stage return feeder 5 via a first-stage gas-solid separator 4. Under the action of high-temperature flue gas I at a flow rate of 1 m / s, it is activated at 850℃ for 5 minutes. The activated SDCCa-4 then undergoes a second-stage gas-solid separator 6 and a second-stage return feeder 7 for recycling.
[0088] Example 11
[0089] Pretreated 9mm biomass feedstock and catalyst microspheres SDCCa-5 were mixed at a mass ratio of 1:10 and fed into fluidized bed gasification reactor 1. Under fluidization conditions of a mixed gas (water vapor to oxygen volume ratio of 1:0.05) at a flow rate of 5 m / s, heat and mass transfer occurred between the feedstock and SDCCa-5. The gasification reaction was carried out at 700℃ for 15 s, producing high-quality hydrogen product with a hydrogen concentration of 79% and a tar content of 8 mg / Nm³. 3 The ash content is 35 mg / Nm³. 3The entire process achieves a hydrogen yield of 108 g / kg dry biomass. After gasification, SDCCa-5 and gasified coke residue are fed from feeder 2 into riser regenerator 3 under the action of a feed air flow of 1 m / s (water vapor to air volume ratio of 1:0.05). Two-stage oxygen-deficient combustion regeneration is performed at 900℃, with the first stage air flow rate at 20 m / s and the second stage at 10 m / s, for a regeneration time of 10 s, yielding regenerated SDCCa-5. Simultaneously, high-temperature CO2-rich flue gas I is generated, with a CO2 content of 25% and a CO content of 11%. The regenerated SDCCa-5 is then fed into a primary gas-solid separator 4 and a primary return feeder 5, where it is activated for 5 minutes at 900℃ under the action of high-temperature flue gas I at a flow rate of 1 m / s. The activated SDCCa-5 then undergoes a secondary gas-solid separator 6 and a secondary return feeder 7 for recycling.
[0090] Example 12
[0091] Pretreated 9mm biomass feedstock and catalyst microspheres SDCCa-6 were mixed at a mass ratio of 1:10 and fed into fluidized bed gasification reactor 1. Under fluidization conditions of a mixed gas (water vapor to oxygen volume ratio of 1:0.05) at a flow rate of 5 m / s, heat and mass transfer occurred between the feedstock and SDCCa-6. The gasification reaction was carried out at 720℃ for 20 s, producing high-quality hydrogen product with a hydrogen concentration of 76% and a tar content of 9 mg / Nm³. 3 The ash content is 28 mg / Nm³. 3 The entire process achieves a hydrogen yield of 96 g / kg dry biomass. After gasification, SDCCa-6 and gasified coke residue are fed from feeder 2 into riser regenerator 3 under the action of feed air at a flow rate of 1 m / s (water vapor to air volume ratio of 1:0.05). Two-stage oxygen-deficient combustion regeneration is performed at 900℃, with the first stage air flow rate at 20 m / s and the second stage air flow rate at 10 m / s, for a regeneration time of 8 s, yielding regenerated SDCCa-6. Simultaneously, high-temperature CO2-rich flue gas I is generated, with a CO2 content of 28% and a CO content of 10%. The regenerated SDCCa-6 is then fed into a primary gas-solid separator 4 and a primary return feeder 5, where it is activated for 5 minutes at 900℃ under the action of high-temperature flue gas I at a flow rate of 1 m / s. The activated SDCCa-6 is then recycled through a secondary gas-solid separator 6 and a secondary return feeder 7.
[0092] Comparative Example 1
[0093] Calcium nitrate and aluminum nitrate were prepared into 0.5 mol / L and 0.5 mol / L solutions, respectively. The solutions were weighed according to a metal element molar ratio of 10:0.6, with aluminum nitrate as feed stream I. 0.1 mol / L sodium dodecyl sulfate and 5 mol / L ammonia were added dropwise to the calcium nitrate solution, and the pH was adjusted to 8. The mixture was then continuously stirred at 40°C until a nanoemulsion was formed, yielding feed stream II. Feed stream I, 0.2 mol / L ammonium citrate, and 0.2 mol / L ammonium bicarbonate were then added dropwise to feed stream II in three separate steps. The mixture was continuously stirred at 60°C to obtain feed stream III. Feed stream III was dried at 105°C for 6 hours, calcined at 800°C for 4 hours, and ground into a fine powder to obtain the catalyst powder.
[0094] The catalyst powder was mixed with polyvinylpyrrolidone at a mass ratio of 1:0.04. Then, 50% of the total weight of the mixture was added as a base material to a centrifugal granulator for granulation. The granulation conditions were as follows: atomizing disc speed of 800 rpm, inlet air speed of 600 rpm, inlet air temperature of 80℃, exhaust air speed of 400 rpm, and peristaltic pump injection speed of 100 rpm. During the granulation process, a 0.05 mol / L guar gum powder solution was continuously sprayed in. After the mixture became small particles, the remaining mixture and guar gum powder solution were added. The guar gum powder and the mixed powder were added at a mass ratio of 0.1:1, causing the small particles to gradually enlarge into microspheres, thus obtaining 0.2 mm catalyst microspheres CSDCCa-1.
[0095] Comparative Example 2
[0096] Calcium nitrate and nickel nitrate were prepared into 0.5 mol / L solutions, respectively. The solutions were weighed according to a metal element molar ratio of 10:0.3, with nickel nitrate as feed stream I. 0.1 mol / L sodium dodecyl sulfate and 5 mol / L ammonia were added dropwise to the calcium nitrate solution, and the pH was adjusted to 8. The mixture was then continuously stirred at 40°C until a nanoemulsion was formed, yielding feed stream II. Feed stream I, 0.2 mol / L ammonium citrate, and 0.2 mol / L ammonium bicarbonate were then added dropwise to feed stream II in three separate steps, and the mixture was continuously stirred at 60°C to obtain feed stream III. Feed stream III was dried at 105°C for 6 hours, calcined at 800°C for 4 hours, and ground into a fine powder to obtain the catalyst powder.
[0097] The catalyst powder was mixed with polyvinylpyrrolidone at a mass ratio of 1:0.04. Then, 50% of the total weight of the mixture was added as a base material to a centrifugal granulator for granulation. The granulation conditions were as follows: atomizing disc speed of 800 rpm, inlet air speed of 600 rpm, inlet air temperature of 80℃, exhaust air speed of 400 rpm, and peristaltic pump injection speed of 100 rpm. During the granulation process, a 0.05 mol / L guar gum powder solution was continuously sprayed in. After the mixture became small particles, the remaining mixture and guar gum powder solution were added, with the guar gum powder and mixed powder at a mass ratio of 0.1:1, causing the small particles to gradually enlarge into microspheres, thus obtaining 0.2 mm catalyst microspheres CSDCCa-2.
[0098] Comparative Example 3
[0099] Calcium nitrate, aluminum nitrate, and nickel nitrate were prepared into solutions with concentrations of 0.5 mol / L, 0.5 mol / L, and 0.5 mol / L, respectively. These solutions were weighed according to a metal element molar ratio of 10:0.6:0.3. Aluminum nitrate and nickel nitrate were thoroughly mixed to form feed stream I, which was set aside. 5 mol / L ammonia was added dropwise to the calcium nitrate solution to adjust the pH to 8. Then, under a temperature of 40°C, the mixture was continuously stirred to obtain feed stream II. Feed stream I, 0.2 mol / L ammonium citrate, and 0.2 mol / L ammonium bicarbonate were then added dropwise to feed stream II in three separate steps. Under a temperature of 60°C, the mixture was continuously stirred to obtain feed stream III. Feed stream III was dried at 105°C for 6 hours, calcined at 800°C for 4 hours, and ground into a fine powder to obtain the catalyst powder.
[0100] The catalyst powder was mixed with polyvinylpyrrolidone at a mass ratio of 1:0.04. Then, 50% of the total weight of the mixture was added as a base material to a centrifugal granulator for granulation. The granulation conditions were as follows: atomizing disc speed of 800 rpm, inlet air speed of 600 rpm, inlet air temperature of 80℃, exhaust air speed of 400 rpm, and peristaltic pump injection speed of 100 rpm. During the granulation process, a 0.05 mol / L guar gum powder solution was continuously sprayed in. After the mixture became small particles, the remaining mixture and guar gum powder solution were added. The guar gum powder and the mixed powder were added at a mass ratio of 0.1:1, causing the small particles to gradually enlarge into microspheres, thus obtaining 0.2 mm catalyst microspheres CSDCCa-3.
[0101] Comparative Example 4
[0102] Calcium nitrate, aluminum nitrate, and nickel nitrate were prepared into solutions with concentrations of 0.5 mol / L, 0.5 mol / L, and 0.5 mol / L, respectively. These solutions were weighed according to a metal element molar ratio of 10:0.6:0.3. Aluminum nitrate and nickel nitrate were thoroughly mixed to form feed stream I, which was then set aside. 0.1 mol / L sodium dodecyl sulfate and 5 mol / L ammonia were added dropwise to the calcium nitrate solution, and the pH was adjusted to 8. The mixture was then continuously stirred at 40°C until a nanoemulsion was formed, yielding feed stream II. Feed stream I, 0.2 mol / L ammonium citrate, and 0.2 mol / L ammonium bicarbonate were then added dropwise to feed stream II. The mixture was continuously stirred at 60°C to obtain feed stream III. Feed stream III was dried at 105°C for 6 hours, calcined at 800°C for 4 hours, and ground into a fine powder to obtain the catalyst powder.
[0103] The catalyst powder was mixed with polyvinylpyrrolidone at a mass ratio of 1:0.04. Then, 50% of the total weight of the mixture was added as a base material to a centrifugal granulator for granulation. The granulation conditions were as follows: atomizing disc speed of 800 rpm, inlet air speed of 600 rpm, inlet air temperature of 80℃, exhaust air speed of 400 rpm, and peristaltic pump injection speed of 100 rpm. During the granulation process, a 0.05 mol / L guar gum powder solution was continuously sprayed in. After the mixture became small particles, the remaining mixture and guar gum powder solution were added. The guar gum powder and the mixed powder were added at a mass ratio of 0.1:1, causing the small particles to gradually enlarge into microspheres, thus obtaining 0.2 mm catalyst microspheres CSDCCa-4.
[0104] Comparative Example 5
[0105] Pretreated 9mm biomass feedstock and catalyst microspheres CSDCCa-1 were mixed at a mass ratio of 1:10 and fed into fluidized bed gasification reactor 1. Under fluidization conditions of a mixed gas (water vapor and oxygen volume ratio of 1:0.01) at a flow rate of 6 m / s, heat and mass transfer occurred between the feedstock and CSDCCa-1. Gasification was carried out at 660℃ for 30 s, producing high-quality hydrogen product with a hydrogen concentration of 69% and a tar content of 50 mg / Nm³. 3 The ash content is 100 mg / Nm³. 3The entire process achieves a hydrogen yield of 79 g / kg dry biomass. The CSDCCa-1, after gasification, and the coke-containing residue from the gasification reaction are fed from feeder 2 into riser regenerator 3 under the action of a feed air flow of 1 m / s (water vapor to air volume ratio of 1:0.05). Two-stage oxygen-deficient combustion regeneration is performed at 900℃, with the first stage air flow rate at 20 m / s and the second stage air flow rate at 10 m / s, for a regeneration time of 10 s, yielding regenerated CSDCCa-1. Simultaneously, high-temperature flue gas I rich in CO2 is generated, with a CO2 content of 25% and a CO content of 12%. The regenerated CSDCCa-1 is then fed into a first-stage gas-solid separator 4 and a first-stage return feeder 5. Under the action of high-temperature flue gas I at a flow rate of 1 m / s, it is activated at 850℃ for 5 minutes. The activated CSDCCa-1 then undergoes a second-stage gas-solid separator 6 and a second-stage return feeder 7 for recycling.
[0106] Comparative Example 6
[0107] Pretreated 9mm biomass feedstock and catalyst microspheres CSDCCa-2 were mixed at a mass ratio of 1:10 and fed into fluidized bed gasification reactor 1. Under fluidization conditions of a mixed gas (water vapor and oxygen volume ratio of 1:0.01) at a flow rate of 6 m / s, heat and mass transfer occurred between the feedstock and CSDCCa-2. The gasification reaction was carried out at 660℃ for 30 s, producing high-quality hydrogen product with a hydrogen concentration of 75% and a tar content of 25 mg / Nm³. 3 The ash content is 60 mg / Nm³. 3 The entire process achieves a hydrogen yield of 88 g / kg dry biomass. The CSDCCa-2, after gasification, and the coke-containing residue from the gasification reaction are fed from feeder 2 into riser regenerator 3 under the action of a feed air flow of 1 m / s (water vapor to air volume ratio of 1:0.05). Two-stage oxygen-deficient combustion regeneration is performed at 900℃, with the first stage air flow rate at 20 m / s and the second stage air flow rate at 10 m / s, for a regeneration time of 10 s, yielding regenerated CSDCCa-2. Simultaneously, high-temperature flue gas I rich in CO2 is generated, with a CO2 content of 25% and a CO content of 12%. The regenerated CSDCCa-2 is then fed into a first-stage return feeder 5 via a first-stage gas-solid separator 4. Under the action of high-temperature flue gas I at a flow rate of 1 m / s, it is activated at 850℃ for 5 minutes. The activated CSDCCa-2 then undergoes a second-stage gas-solid separator 6 and a second-stage return feeder 7 for recycling.
[0108] Comparative Example 7
[0109] Pretreated 9mm biomass feedstock and catalyst microspheres CSDCCa-3 were mixed at a mass ratio of 1:10 and fed into fluidized bed gasification reactor 1. Under fluidization conditions of a mixed gas (water vapor to oxygen volume ratio of 1:0.01) at a flow rate of 6 m / s, heat and mass transfer occurred between the feedstock and CSDCCa-3. The gasification reaction was carried out at 660℃ for 30 s, producing high-quality hydrogen product with a hydrogen concentration of 68% and a tar content of 50 mg / Nm³. 3 The ash content is 80 mg / Nm³. 3 The entire process achieves a hydrogen yield of 75 g / kg dry biomass. The CSDCCa-3, after gasification, and the coke-containing residue from the gasification reaction are fed from feeder 2 into riser regenerator 3 under the action of a feed air flow of 1 m / s (water vapor to air volume ratio of 1:0.05). Two-stage oxygen-deficient combustion regeneration is carried out at 900℃, with the first stage air flow rate at 20 m / s and the second stage air flow rate at 10 m / s, for a regeneration time of 10 s, yielding regenerated CSDCCa-3. Simultaneously, high-temperature flue gas I rich in CO2 is generated, with a CO2 content of 25% and a CO content of 12%. The regenerated CSDCCa-3 is then fed into a first-stage gas-solid separator 4 and a first-stage return feeder 5. Under the action of high-temperature flue gas I with a flow rate of 1 m / s, it is activated at 850℃ for 5 minutes. The activated CSDCCa-3 then undergoes a second-stage gas-solid separator 6 and a second-stage return feeder 7 for recycling.
[0110] Comparative Example 8
[0111] Pretreated 9mm biomass feedstock and catalyst microspheres CSDCCa-4 were mixed at a mass ratio of 1:10 and fed into fluidized bed gasification reactor 1. Under fluidization conditions of a mixed gas (water vapor to oxygen volume ratio of 1:0.01) at a flow rate of 6 m / s, heat and mass transfer occurred between the feedstock and CSDCCa-4. The gasification reaction was carried out at 660℃ for 30 s, producing high-quality hydrogen product with a hydrogen concentration of 79% and a tar content of 20 mg / Nm³. 3 The ash content is 40 mg / Nm³. 3The entire process achieves a hydrogen yield of 100 g / kg dry biomass. The CSDCCa-4, after gasification, and the coke-containing residue from the gasification reaction are fed from feeder 2 into riser regenerator 3 under the action of a feed air flow of 1 m / s (water vapor to air volume ratio of 1:0.05). Two-stage oxygen-deficient combustion regeneration is performed at 900℃, with the first stage air flow rate at 20 m / s and the second stage air flow rate at 10 m / s, for a regeneration time of 10 s, yielding regenerated CSDCCa-4. Simultaneously, high-temperature flue gas I rich in CO2 is generated, with a CO2 content of 25% and a CO content of 12%. The regenerated CSDCCa-4 is then fed into a primary gas-solid separator 4 and a primary return feeder 5, where it is activated for 5 minutes at 850℃ under the action of high-temperature flue gas I at a flow rate of 1 m / s. The activated CSDCCa-4 is then recycled through a secondary gas-solid separator 6 and a secondary return feeder 7.
Claims
1. A method for preparing a catalyst for biomass gasification to produce hydrogen, comprising the following steps: (1) After mixing dopant component A and dopant component B evenly, a material flow I is obtained; dopant component A is a metal soluble salt, and the metal element is one or more of group IIIA elements and group IVB elements; dopant component B is a metal soluble salt, and the metal element is one or more of group IB elements, group VIIB elements and group VIII lanthanide elements. (2) Add anionic surfactant and first precipitant to calcium salt solution, adjust the pH of the system to 8-9, and then mix evenly at 40-60℃ to obtain material flow II; the first precipitant is an alkaline amino compound; (3) Add the material stream I, the second precipitant and the third precipitant obtained in step (1) to the material stream II obtained in step (2), mix them evenly at 70-80°C to obtain material stream III, and then further heat treat to obtain the catalyst; the second precipitant is at least one of oxalate, citrate, succinate and malate; the third precipitant is carbonate; The preparation method of the biomass gasification hydrogen production catalyst firstly involves pH control to precipitate some calcium from its salt solution, which then self-assembles into a nanoscale precursor core under the action of anionic surfactant. Dopant A, dopant B, and the remaining calcium are then distributed around the precursor core through complexation with the anionic surfactant. Further, through the combined use of various precipitants, dopant A, dopant B, and the remaining calcium are simultaneously precipitated from the solution system and uniformly distributed on the surface of the precursor core. After heat treatment, a catalyst with a calcium oxide core and a composite coated shell is prepared.
2. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: Dopant component A is selected from one or more soluble salts containing aluminum, boron, zirconium, and titanium.
3. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: Dopant component A is an aluminum salt and / or a zirconium salt.
4. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: Dopant component A is one or more of aluminum nitrate, aluminum sulfate, aluminum chloride, zirconium nitrate, and zirconium oxychloride.
5. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: Dopant component B is selected from one or more combinations of soluble salts containing nickel, iron, cobalt, copper, manganese, cerium, and lanthanum.
6. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: Dopant component B is one or more of nickel nitrate, iron nitrate, and manganese nitrate.
7. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: The calcium salt is selected from at least one of calcium nitrate, calcium chloride, calcium iodide, calcium pyruvate, calcium nitrite, calcium formate, calcium acetate, calcium propionate, and calcium dodecylbenzenesulfonate.
8. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: The calcium salt was selected as calcium nitrate.
9. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: Anionic surfactants are one or more of the following: fatty acid salts with 15 to 33 carbon atoms, sulfonates with 12 to 20 carbon atoms, and sulfates with 10 to 18 carbon atoms.
10. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 9, characterized in that: Fatty acid salts with 15 to 33 carbon atoms are soaps and / or N-alkyl acyl polypeptides; sulfonates with 12 to 20 carbon atoms are one or more of alkylbenzene sulfonates, α-olefin sulfonates, alkyl sulfonates, α-sulfonyl monocarboxylic acids, fatty acid sulfonyl esters, succinate sulfonates, alkylnaphthalene sulfonates, petroleum sulfonates, lignin sulfonates, and alkyl glycerol ether sulfonates; sulfates with 10 to 18 carbon atoms are fatty alcohol sulfates and / or secondary alkyl sulfates.
11. The method for preparing a catalyst for biomass gasification hydrogen production according to claim 1 or 9, characterized in that: The anionic surfactant is at least one of sodium dodecyl sulfate, sodium hexadecyl sulfonate, sodium dodecylbenzene sulfonate, and sodium lauryl ether sulfate.
12. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: The first precipitant is selected from at least one of ammonia, urea, thiourea, biuret, triuret, methylamine, ethylamine, ethanolamine, ethylenediamine, propylamine, isopropylamine, propylenediamine, dimethylamine, trimethylamine, triethylamine, and C8-C10 aliphatic amines.
13. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: The first precipitant is selected from at least one of ammonia, urea, and ethanolamine.
14. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: Oxalate is selected from at least one of ammonium oxalate, sodium oxalate, and potassium oxalate; citrate is selected from at least one of ammonium citrate, sodium citrate, and potassium citrate; succinate is selected from at least one of ammonium succinate, sodium succinate, and potassium succinate; malate is selected from at least one of ammonium malate, sodium malate, and potassium malate.
15. The method for preparing a catalyst for biomass gasification to hydrogen production according to claim 1, characterized in that: The third precipitant is selected from at least one of ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate.
16. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: Based on the molar ratio of metal elements, the molar ratio of calcium salt, dopant A, and dopant B is 10:0.1 to 1:0.05 to 0.
5.
17. The method for preparing a catalyst for biomass gasification to hydrogen production according to claim 1, characterized in that: The molar ratio of the second precipitant to the dopant component B, based on acid radical anions and metal cations respectively, is 1:0.5 to 1.
18. The method for preparing a catalyst for biomass gasification to hydrogen production according to claim 1, characterized in that: The molar ratio of the third precipitant to dopant component A, based on acid radical anions and metal cations respectively, is 1:0.4 to 0.
8.
19. The method for preparing a catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: The heat treatment in step (3) includes drying heat treatment and calcination heat treatment. The drying heat treatment temperature is 105-140℃ and the drying heat treatment time is 4-6 hours. The calcination heat treatment temperature is 800-900℃ and the calcination heat treatment time is 1-4 hours.
20. The method for preparing the catalyst for biomass gasification hydrogen production according to claim 1, characterized in that: The catalyst obtained in step (3) is subjected to molding treatment.
21. The method for preparing a catalyst for biomass gasification to hydrogen production according to claim 20, characterized in that: The molding steps for microspherical catalysts are as follows: S1: First, the catalyst powder and dispersant are mixed to obtain a mixture; S2: A portion of the mixture obtained in step S1 is added to a centrifugal granulator as a base material for granulation. During the granulation process, a binder solution is continuously sprayed in. After the mixture becomes small particles, the remaining mixture and binder solution are sprayed in simultaneously until the required microsphere catalyst is obtained.
22. The method for preparing a catalyst for biomass gasification to hydrogen production according to claim 21, characterized in that: The dispersant is selected from one or more of polyethylene glycol 200, polyethylene glycol 400, polyacrylamide, maleic acid copolymer, polycarboxylate, polyvinylpyrrolidone, and potassium sorbate; the mass ratio of the dispersant to the mixture is 0.01 to 0.05:
1.
23. The method for preparing a catalyst for biomass gasification to hydrogen production according to claim 21, characterized in that: The binder is selected from one or more of microcrystalline cellulose, hydroxypropyl methylcellulose, polyvinyl alcohol, cyclodextrin, guar gum, starch, aluminum sol, nitric acid, and citric acid; the mass ratio of binder to the mixture is 0.05 to 0.2:1, and the molar concentration of the binder solution is 0.01 to 0.1 mol / L.
24. A catalyst for biomass gasification to produce hydrogen, said catalyst being prepared by the method described in any one of claims 1-23.
25. A method for producing hydrogen from biomass gasification, comprising the following steps: (a) The pretreated biomass feedstock enters the gasification reactor, where hydrogen and gasified coke residue are generated under the combined action of fluidizing air and catalyst; the catalyst is obtained by the preparation method described in any one of claims 1-23; (b) The catalyst to be regenerated after the reaction and the gasified coke residue enter the riser regenerator under the action of the feed air, and the catalyst to be regenerated is regenerated by oxidation and combustion, and high temperature flue gas I is generated. (c) The regenerated catalyst is sent to the primary return feeder after gas-solid separation. It is activated by high-temperature flue gas I. The activated catalyst is then returned to the gasification reactor for recycling after further gas-solid separation.
26. The method for producing hydrogen by biomass gasification according to claim 25, characterized in that: In step (a), the fluidizing air is one or more of the following: water vapor, water vapor and oxygen mixture, with a volume ratio of water vapor to oxygen of 1:0.01 to 0.
1. Under normal operating conditions, the flow velocity of the fluidizing air is 5 to 20 m / s.
27. The method for producing hydrogen by biomass gasification according to claim 26, characterized in that: In step (a), the fluidizing air is a mixture of water vapor and oxygen.
28. The method for producing hydrogen by biomass gasification according to claim 25, characterized in that: The operating conditions of the gasification reactor in step (a) are: temperature 620-720℃, reaction time 10-30s.
29. The method for producing hydrogen by biomass gasification according to claim 25, characterized in that: In step (a), the mass ratio of biomass feedstock to catalyst is 1:5 to 10.
30. The method for producing hydrogen by biomass gasification according to claim 25, characterized in that: The feed air in step (b) is a mixture of water vapor and carrier gas, wherein the carrier gas is at least one of nitrogen, oxygen and air, and the volume ratio of water vapor to carrier gas is 1:0.05 to 0.
2.
31. The method for producing hydrogen from biomass gasification according to claim 30, characterized in that: The feed air in step (b) is a mixture of water vapor and air.
32. The method for producing hydrogen by biomass gasification according to claim 25, characterized in that: The regeneration conditions for the riser regenerator in step (b) are: regeneration temperature of 850-950℃, regeneration time of 5-10s, and regeneration atmosphere of air.
33. The method for producing hydrogen by biomass gasification according to claim 25, characterized in that: The catalyst pore-forming activation conditions in step (c) are as follows: temperature is 850-900℃, and activation time is 1-5 min.