Iron-calcium main agent type multi-component gasification-adsorption dual functional material, preparation method and application thereof

Abstract

This invention discloses a multi-component gasification-adsorption bifunctional material with iron and calcium as the main agents, its preparation method, and its applications. The material includes a support, main agents, and excipients. The support is porous carbon, and both the main agents and excipients are loaded onto the support. The main agents include iron-based oxides, CaO, and ZnO, with loadings of 15%-25%, 10%-20%, and 3%-8%, respectively. The excipients are potassium-based oxides, with a loading of 3%-8%. The achieved technical effects are: the main agents are low-cost iron, calcium, and zinc, supplemented with a small amount of potassium, reducing the overall cost by 50%-70%. It can achieve tar cracking in the high-temperature zone and catalytic Fischer-Tropsch synthesis to produce gasoline and diesel in the low-temperature zone. Through multi-mechanism synergy, it can effectively control Pb... 2+ Cd 2+ Cu 2+ Removal rate >99%, Hg 2+ As 3+ Removal rate >99.9%, Cr 6+ Removal rate >98%. Can be recovered through magnetic separation, avoiding secondary pollution.

Description

Technical Field

[0001] This invention relates to the field of heavy metal pollution control technology, specifically to a multi-component gasification-adsorption dual-functional material with iron and calcium as the main active ingredient, a method for preparing the multi-component gasification-adsorption dual-functional material with iron and calcium as the main active ingredient, and the application of the multi-component gasification-adsorption dual-functional material with iron and calcium as the main active ingredient in gasification reactions, wastewater treatment, or soil remediation. Background Technology

[0002] Gasification of waste such as municipal solid waste, biomass, and sludge is an important technological approach to achieve waste reduction, harmlessness, and resource utilization. However, existing gasification technologies still face a series of prominent challenges in practical applications, which restrict their large-scale promotion and operational stability.

[0003] First, the tar produced during gasification (mainly including polycyclic aromatic hydrocarbons such as naphthalene, anthracene, and phenanthrene) is highly susceptible to condensation and polymerization in the pipeline system, leading to pipe blockage, equipment corrosion, and catalyst deactivation, severely impacting the continuous and stable operation of the system. Second, heavy metals commonly found in waste (such as Pb, Cd, Hg, As, and Cr) volatilize into the syngas or accumulate in the ash under high-temperature gasification conditions, posing a potential risk of secondary pollution and increasing the difficulty of subsequent purification and disposal. Third, traditional gasification processes typically require temperatures above 900℃, resulting in high energy consumption and poor economic efficiency. Furthermore, the main components of conventional gasification products are H2 and CO, with low added value in the syngas and a lack of high-value chemical components, limiting the comprehensive utilization value of the gasification products.

[0004] Meanwhile, the treatment of heavy metal wastewater and the remediation of contaminated soil are also key and challenging issues in the current environmental governance field. Among existing technologies, chemical precipitation is widely used, but it generates large amounts of sludge containing heavy metals, posing serious secondary pollution problems. Ion exchange methods are limited by high resin costs, and the regenerated wastewater is difficult to treat properly. Activated carbon adsorption generally has a low adsorption capacity for heavy metals (approximately 30 mg / g-50 mg / g) and lacks selective adsorption capabilities. Overall, existing materials have relatively limited functions and cannot simultaneously address the multiple challenges of tar cracking, catalytic gasification, syngas upgrading, and heavy metal stabilization during gasification processes. Furthermore, they cannot achieve efficient removal of heavy metals from wastewater and soil within the same material system. Summary of the Invention

[0005] Therefore, this invention provides a multi-component gasification-adsorption dual-function material with iron and calcium as the main agents, its preparation method, and its application. The material uses a continuous carbon skeleton as a carrier and loads iron and calcium main agents (Fe2O3 / Fe3O4, CaO, ZnO) and potassium auxiliary agent (K2O). During the gasification process, it simultaneously performs four major functions: catalytic gasification, tar cracking, Fischer-Tropsch synthesis, and heavy metal stabilization. It can also be directly used for heavy metal wastewater treatment and contaminated soil remediation, realizing the efficient and clean conversion and high-value utilization of waste.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] According to a first aspect of the present invention, a multi-component gasification-adsorption bifunctional material with iron and calcium as the main agent includes a support, a main agent component and an auxiliary agent, wherein the support is porous carbon, and both the main agent component and the auxiliary agent are loaded on the support;

[0008] The main components include iron-based oxides, CaO, and ZnO, with loadings of 15%-25%, 10%-20%, and 3%-8%, respectively.

[0009] The excipient is a potassium-based oxide, and the loading of the excipient is 3%-8%.

[0010] Furthermore, the iron-based oxide includes Fe2O3 and Fe3O4, and the auxiliary agent is K2O.

[0011] Furthermore, the porous carbon is a lignin-semi-coke composite porous material with a specific surface area of ​​200 m². 2 / g-500m 2 / g, with a mesopore size of 5nm-50nm, a mesopore ratio of >40%, a thermal conductivity of >50 W / (m·K), a compressive strength of >80N, and a surface oxygen-containing functional group content of 1mmol / g-3mmol / g.

[0012] Furthermore, the material is shaped granules with a particle size of 2mm-10mm.

[0013] The present invention has the following advantages:

[0014] 1. Low cost and high cost performance

[0015] Main agents (iron, calcium, zinc): low cost (derived from iron ore and lime), providing main functions such as tar cracking, Fischer-Tropsch synthesis, and heavy metal stabilization;

[0016] Additive (potassium): Small dosage (3%-8%), precisely exerting the key function of gasification catalysis;

[0017] The overall cost is reduced by 50%-70% compared to the pure zinc / potassium system.

[0018] 2. Possesses dual functions of tar cracking and Fischer-Tropsch synthesis.

[0019] High-temperature zone (500℃-700℃): Iron-based catalytic tar cracking reduces tar content by more than 80%;

[0020] Low-temperature region (200℃-350℃): Iron-based catalytic Fischer-Tropsch synthesis, with products mainly consisting of gasoline, aviation kerosene, and diesel;

[0021] The same catalyst can perform different functions in different temperature zones, enabling relay catalysis within the reactor.

[0022] 3. Synergistic effect of gasification catalysis and heavy metal stabilization

[0023] K2O can lower the gasification temperature by 100℃-150℃ and increase the carbon conversion rate by 15%-25%;

[0024] CaO, ZnO, and Fe2O3 stabilize heavy metals in situ; the volatilization rate of Pb, Cd, Hg, As, and Cr is reduced by more than 90%; and the leaching toxicity of ash residue meets the standards.

[0025] 4. Structural advantages of continuous carbon skeleton

[0026] Mesopores (5nm-50nm) provide a dispersion carrier for multi-component active components with high utilization rate;

[0027] High thermal conductivity (>50W / (m·K)) ensures uniform heat transfer and avoids localized overheating;

[0028] Polycyclic aromatic hydrocarbons (graphite microcrystals) have a rigid framework that resists volume expansion, while amorphous carbon buffers stress, combining rigidity and flexibility.

[0029] Surface oxygen-containing functional groups (-OH, -COOH) provide complexation adsorption sites.

[0030] 5. It can be recycled through magnetic separation, avoiding secondary pollution.

[0031] Iron-based (Fe3O4) imparts magnetism to the material, and the separation and recovery rate is >98% after 5 minutes with an external magnetic field (0.5T).

[0032] 6. Can utilize multiple mechanisms to synergistically process various heavy metals.

[0033] Cr 6+ Through Fe 2+ Reduction and fixation, removal rate >98%;

[0034] Hg 2+ As 3+ It can be removed by ZnO sulfide precipitation, with a removal rate >99.9%;

[0035] Pb 2+Cd 2+ Cu 2+ The removal rate is >99% through CaO chemical precipitation + K2O ion exchange + carbon skeleton complexation.

[0036] 7. It exhibits excellent performance in wastewater treatment and soil remediation.

[0037] (1) In terms of heavy metal wastewater treatment

[0038] Synergistic effect of multiple mechanisms: CaO chemical precipitation + K2O ion exchange + ZnO sulfide precipitation + Fe 2+ Reduction fixation + carbon framework complex adsorption;

[0039] For Pb 2+ Cd 2+ Cu 2+ With a removal rate >99%, for Hg 2+ As 3+ Removal rate >99.9%, for Cr 6+ Removal rate >98%;

[0040] Adsorption capacity: Pb 2+ The adsorption capacity is 99 mg / g (approximately 3 times that of activated carbon), Cd 2+ The adsorption capacity is 49.6 mg / g (approximately 2.5 times that of activated carbon).

[0041] It can be recycled through magnetic separation. With an external magnetic field applied for 5 minutes, the separation and recovery rate is >98%, avoiding the traditional adsorbent from becoming a new solid waste.

[0042] (2) In terms of soil heavy metal remediation

[0043] In-situ stabilization: CaO, ZnO, Fe2O3 react with Pb, Cd, Hg, As, and Cr to form stable compounds (Ca2PbO4, ZnS, Ca3(AsO4)2, etc.), converting the migratable heavy metals into a stable state;

[0044] The leaching toxicity is reduced by more than 90%, meeting the GB 5085.3-2007 standard;

[0045] Magnetic separation can be used to separate the materials: after remediation, the materials can be recovered by applying an external magnetic field, achieving soil purification and material recycling, and avoiding secondary pollution;

[0046] Multiple uses in one application: The same material can treat multiple heavy metals simultaneously, eliminating the need for step-by-step treatment.

[0047] According to a second aspect of the present invention, a method for preparing a multi-component gasification-adsorption bifunctional material with iron and calcium as the main agent, for preparing the material described in the first aspect, includes the following specific steps:

[0048] S1. Loading of main agent components: Loading the main agent components onto the carrier using the impregnation method, including the following specific sub-steps:

[0049] S101. Immerse the carrier in a mixed solution of ferric acetate, calcium acetate and zinc acetate for 0.5h-2h.

[0050] S102, Remove and dry;

[0051] S103, calcined in an inert gas atmosphere, yields Fe2O3 / CaO / ZnO / carbon composite material;

[0052] S2, Excipient Loading: Excipients are loaded using the impregnation method.

[0053] Furthermore, step S2 includes the following specific sub-steps:

[0054] S201. Immerse the material obtained in step S1 in KOH solution for 0.5h-2h.

[0055] S202, Remove and dry;

[0056] S2O3 was calcined at 300℃-400℃ in an inert gas atmosphere for 1-3 hours to obtain a K2O / Fe2O3 / CaO / ZnO / carbon composite material.

[0057] Further, in step S101, the concentration of ferric acetate is 0.5 mol / L-1.5 mol / L, the concentration of calcium acetate is 0.2 mol / L-1.0 mol / L, and the concentration of zinc acetate is 0.1 mol / L-0.5 mol / L;

[0058] The drying temperature in step S102 is 80℃-120℃, and the drying time is 2h-6h;

[0059] The calcination temperature in step S103 is 400℃-500℃, and the calcination time is 2h-4h;

[0060] In step S201, the concentration of KOH is 0.2 mol / L - 1.0 mol / L;

[0061] The drying temperature in step S202 is 80℃-120℃, and the drying time is 2h-6h.

[0062] Furthermore, it also includes step S3, activation: reducing the material obtained in step S2 in a hydrogen atmosphere at 300℃-350℃ for 1h-2h to obtain a material containing Fe. 2+ K2O / Fe3O4 / CaO / ZnO / carbon composite material.

[0063] Furthermore, the method for preparing the carrier in step S1 is as follows:

[0064] S001. Coal powder and enzymatically hydrolyzed lignin powder are mixed at a ratio of 10:1 to 5:1 and subjected to supercritical carbon dioxide dynamic cyclic pyrolysis at 280℃-320℃ and 8MPa-20MPa to obtain lignin-semi-coke composite carbon skeleton powder.

[0065] S002. Add carbon skeleton powder to alkaline solution, heat and stir, then use density difference to separate by flotation and collect the upper effective component;

[0066] S003, Granulation: The collected upper effective components are calcined in an inert atmosphere at 300℃-500℃ to obtain porous carbon particle carriers.

[0067] The present invention has the following advantages:

[0068] Simplified process for green and environmentally friendly use:

[0069] The process involves one-step co-impregnation with acetates (ferric acetate, calcium acetate, and zinc acetate). All three are soluble acetates and do not react with each other. The decomposition products upon calcination are only CO2 and H2O, with no NO. X emission;

[0070] Stepwise impregnation with potassium source can prevent the formation of Zn(OH)2 precipitate by KOH and zinc acetate, ensuring uniform distribution of active components;

[0071] The process requires only two steps of impregnation and two firings, which simplifies the operation and reduces production costs.

[0072] According to a third aspect of the present invention, an iron-calcium main formulation multi-component gasification-adsorption bifunctional material is used in gasification reactions, wastewater treatment or soil remediation. Attached Figure Description

[0073] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0074] Figure 1 The present invention provides a process flow diagram for the preparation of a multi-component gasification-adsorption bifunctional material with iron and calcium as the main dosage form. Detailed Implementation

[0075] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0076] Example 1

[0077] A first aspect embodiment of the present invention provides a multi-component gasification-adsorption bifunctional material with iron and calcium as the main agent, comprising a support, a main agent component, and an auxiliary agent, wherein the support is porous carbon, and both the main agent component and the auxiliary agent are loaded on the support;

[0078] The main components include iron-based oxides, CaO, and ZnO. The loading of iron-based oxides is 15%-25%, the loading of CaO is 10%-20%, and the loading of ZnO is 3%-8%.

[0079] Iron-based oxides are used to provide functions such as tar cracking, Fischer-Tropsch synthesis, water-gas shift, and magnetic separation and recovery.

[0080] CaO is used to provide chemical precipitation to stabilize heavy metals, adjust pH, and capture CO2.

[0081] ZnO provides sulfide precipitation properties, and Hg 2+ As 3+ High efficiency and selectivity;

[0082] The main components are derived from iron ore and limestone, resulting in extremely low costs.

[0083] The excipient is a potassium-based oxide, and the loading of the excipient is 3%-8%.

[0084] In this embodiment, it should be noted that the loading of the main component and the auxiliary component are both measured by weight. The iron-based oxides include Fe2O3 and / or Fe3O4, and the auxiliary component is K2O, which is used to provide gasification catalysis, ion exchange and precipitation promotion functions.

[0085] The technical effect achieved by this embodiment is as follows:

[0086] 1. Low cost and high cost performance

[0087] Main agents (iron, calcium, zinc): low cost (derived from iron ore and lime), used to provide the main functions of tar cracking, Fischer-Tropsch synthesis, and heavy metal stabilization;

[0088] Additive (potassium): Used in small amounts (3%-8%), it is used to precisely exert the key function of gasification catalysis;

[0089] The overall cost is reduced by 50%-70% compared to the pure zinc / potassium system.

[0090] 2. Possesses dual functions of tar cracking and Fischer-Tropsch synthesis.

[0091] High-temperature zone (500℃-700℃): Iron-based catalytic tar cracking reduces tar content by more than 80%;

[0092] Low-temperature region (200℃-350℃): Iron-based catalytic Fischer-Tropsch synthesis, with products mainly consisting of gasoline, aviation kerosene, and diesel;

[0093] The same catalyst can perform different functions in different temperature zones, enabling relay catalysis within the reactor.

[0094] 3. Synergistic effect of gasification catalysis and heavy metal stabilization

[0095] K2O can lower the gasification temperature by 100℃-150℃ and increase the carbon conversion rate by 15%-25%;

[0096] CaO, ZnO, and Fe2O3 stabilize heavy metals in situ; the volatilization rate of Pb, Cd, Hg, As, and Cr is reduced by more than 90%; and the leaching toxicity of ash residue meets the standards.

[0097] 4. It can be recycled through magnetic separation, avoiding secondary pollution.

[0098] Iron-based (Fe3O4) imparts magnetism to the material, and the separation and recovery rate is >98% after 5 minutes with an external magnetic field (0.5T).

[0099] 5. Can utilize multiple mechanisms to synergistically process various heavy metals.

[0100] Cr 6+ Through Fe 2+ Reduction and fixation, removal rate >98%;

[0101] Hg 2+ As 3+ It can be removed by ZnO sulfide precipitation, with a removal rate >99.9%;

[0102] Pb 2+ Cd 2+ Cu 2+ The removal rate is >99% through CaO chemical precipitation + K2O ion exchange + carbon skeleton complexation.

[0103] 6. It exhibits excellent performance in wastewater treatment and soil remediation.

[0104] (1) In terms of heavy metal wastewater treatment

[0105] Synergistic effect of multiple mechanisms: CaO chemical precipitation + K2O ion exchange + ZnO sulfide precipitation + Fe 2+Reduction fixation + carbon framework complex adsorption;

[0106] For Pb 2+ Cd 2+ Cu 2+ With a removal rate >99%, for Hg 2+ As 3+ Removal rate >99.9%, for Cr 6+ Removal rate >98%;

[0107] Adsorption capacity: Pb 2+ The adsorption capacity is 99 mg / g (approximately 3 times that of activated carbon), Cd 2+ The adsorption capacity is 49.6 mg / g (approximately 2.5 times that of activated carbon).

[0108] It can be recycled through magnetic separation: the separation and recovery rate is >98% after 5 minutes of applying an external magnetic field, thus avoiding the traditional adsorbent from becoming a new solid waste.

[0109] (2) In terms of soil heavy metal remediation

[0110] In-situ stabilization: CaO, ZnO, Fe2O3 react with Pb, Cd, Hg, As, and Cr to form stable compounds (Ca2PbO4, ZnS, Ca3(AsO4)2, etc.), converting the migratable heavy metals into a stable state;

[0111] The leaching toxicity is reduced by more than 90%, meeting the GB 5085.3-2007 standard;

[0112] Magnetic separation can be used to separate the materials: after remediation, the materials can be recovered by applying an external magnetic field, achieving soil purification and material recycling, and avoiding secondary pollution;

[0113] Multiple uses in one application: The same material can treat multiple heavy metals simultaneously, eliminating the need for step-by-step treatment.

[0114] Example 2

[0115] This embodiment provides another iron-calcium main formulation multi-component gasification-adsorption dual-function material, which includes all the contents of Example 1. Only the different parts are described below.

[0116] In this embodiment, the loading of iron-based oxides is 18%, the loading of CaO is 15%, the loading of ZnO is 5%, and the loading of K2O is 4%.

[0117] Porous carbon is a lignin-semi-coke composite porous material. After lignin carbonization, it forms a continuous, interface-free structure with semi-coke through chemical bonding, eliminating the need for external binders. It retains the composite structure of polycyclic aromatic hydrocarbons (graphite microcrystals) and amorphous carbon, achieving a balance of rigidity and flexibility. Its specific surface area is 200 m². 2 / g-500m2 / g, with a mesopore size of 5nm-50nm, a mesopore ratio of >40%, a thermal conductivity of >50 W / (m·K), a compressive strength of >80N, and a surface oxygen-containing functional group (hydroxyl, carboxyl, carbonyl) content of 1mmol / g-3mmol / g.

[0118] In this embodiment, it should be noted that the material is a molded particle with a particle size of 2mm-10mm. This material can be used for tar cracking, Fischer-Tropsch synthesis, gasification catalysis, water-gas conversion, heavy metal stabilization (gasification), heavy metal adsorption (wastewater / soil), etc., and can perform multiple mechanisms of synergistic fixation, complexation adsorption, etc.

[0119] When used for tar pyrolysis, the active components in the material are Fe2O3 / Fe3O4, and the target is tar (C). m H m The reaction process is as follows: C m H m +nH2O→nCO+(n+m / 2)H2, which can reduce tar content by more than 80%;

[0120] When used in Fischer-Tropsch synthesis, the active component in the material is Fe2O3 / Fe3O 4， The target of the reaction is syngas (H2+CO), and the reaction process is as follows: CO+2H2→-CH2-+H2O, with gasoline, aviation kerosene and diesel as the main products;

[0121] When used for gasification catalysis, the active component in the material is K2O, the target of which is carbon feedstock, and the working principle is to reduce the gasification activation energy, which can increase the carbon conversion rate by 15%-25%.

[0122] When used in water-gas conversion, the active component in the material is Fe3O4, and the target of the reaction is CO + H2O. The reaction process is as follows: CO + H2O → CO2 + H2.

[0123] When used for heavy metal stabilization (gasification), the active components in the material are CaO, ZnO, and Fe2O3, and the targets are Pb, Cd, Hg, As, and Cr. It can form stable compounds such as Ca2PbO4, ZnS, and Ca3(AsO4)2, thereby reducing the volatility.

[0124] When used for heavy metal adsorption (wastewater / soil), the active components in the material are CaO, ZnO, Fe2O3, and K2O, and the target metal is Pb. 2+ Cd 2+ Hg 2+ As 3+ Cr 6+ The reaction principle involves a synergistic effect of multiple mechanisms, including chemical precipitation, ion exchange, sulfide precipitation, reduction fixation, and complexation adsorption.

[0125] After the materials are used up, an external magnetic field can be used to separate and recycle them, avoiding secondary pollution.

[0126] The technical effect achieved by this embodiment is as follows:

[0127] The structural advantages of having a continuous carbon framework:

[0128] Mesopores (5nm-50nm) provide a dispersion carrier for multi-component active components with high utilization rate;

[0129] High thermal conductivity (>50W / (m·K)) ensures uniform heat transfer and avoids localized overheating;

[0130] Polycyclic aromatic hydrocarbons (graphite microcrystals) have a rigid framework that resists volume expansion, while amorphous carbon buffers stress, combining rigidity and flexibility.

[0131] Surface oxygen-containing functional groups (-OH, -COOH) provide complexation adsorption sites.

[0132] It is also applicable to multiple scenarios. The same material can play a role in the high-temperature zone, medium-temperature zone, low-temperature zone of the gasifier and in subsequent wastewater / soil treatment, achieving "one agent for multiple uses".

[0133] Example 3

[0134] like Figure 1 As shown, the second aspect of the present invention discloses a method for preparing a multi-component gasification-adsorption bifunctional material with iron and calcium as the main agent, used to prepare the material in the first aspect. The method employs a two-step loading method to form an iron-calcium-zinc main agent layer and a potassium auxiliary agent layer, and includes the following specific steps:

[0135] S1. Loading of main components: The main components are loaded onto the carrier by one-step co-impregnation using the impregnation method, including the following specific sub-steps:

[0136] S101. Immerse the carrier in a mixed solution of ferric acetate, calcium acetate and zinc acetate, wherein the concentration of ferric acetate is 0.5 mol / L-1.5 mol / L, the concentration of calcium acetate is 0.2 mol / L-1.0 mol / L, and the concentration of zinc acetate is 0.1 mol / L-0.5 mol / L, for 0.5 h-2 h.

[0137] S102. Remove and dry at a temperature of 80℃-120℃ for 2-6 hours.

[0138] S103 is calcined in an inert gas atmosphere (such as N2, Ar) at a temperature of 400℃-500℃ for 2-4 hours. During calcination, ferric acetate, calcium acetate, and zinc acetate decompose into Fe2O3, CaO, ZnO, and CO. 2、H2O produces no toxic gas emissions, resulting in a Fe2O3 / CaO / ZnO / carbon composite material;

[0139] S2, Excipient Loading: The excipient is loaded using the impregnation method. Step S2 includes the following specific sub-steps:

[0140] S201. Immerse the material obtained in step S1 in a 0.2 mol / L-1.0 mol / L KOH solution and stir and soak at 80℃-95℃ for 0.5h-2h.

[0141] S202. Remove and dry at a temperature of 80℃-120℃ for 2-6 hours.

[0142] S2O3 is calcined at 300℃-400℃ in an inert gas atmosphere (such as N2, Ar) for 1h-3h to obtain K2O / Fe2O3 / CaO / ZnO / carbon composite material.

[0143] In this embodiment, it should be noted that in step S1, ferric acetate, calcium acetate, and zinc acetate are all soluble acetates, and the three do not react with each other in aqueous solution, thus achieving one-step co-impregnation; the concentrations of ferric acetate, calcium acetate, and zinc acetate can be adjusted according to the target loading amount, and the loading amount can be controlled by changing the concentration of the impregnation solution or the number of repeated impregnations.

[0144] The two-step impregnation process avoids the formation of Zn(OH)2 precipitate from KOH and zinc acetate, ensuring a uniform distribution of the active components.

[0145] The technical effect achieved by this embodiment is as follows:

[0146] 1. Simplified process that is green and environmentally friendly

[0147] The process involves one-step co-impregnation with acetates (ferric acetate, calcium acetate, and zinc acetate). All three are soluble acetates and do not react with each other. The decomposition products upon calcination are only CO2 and H2O, with no NO. X emission;

[0148] 2. The active components are evenly distributed.

[0149] Stepwise impregnation with potassium source can prevent the formation of Zn(OH)2 precipitate by KOH and zinc acetate, ensuring uniform distribution of active components;

[0150] 3. Simplified process and low cost

[0151] The process requires only two steps of impregnation and two firings, which simplifies the operation, reduces production costs, and facilitates industrial production.

[0152] Example 4

[0153] like Figure 1As shown in this embodiment, another method for preparing a multi-component gasification-adsorption bifunctional material with iron and calcium as the main dosage form is provided. It includes all the contents of Example 1, and only the different parts are described below.

[0154] In this embodiment, step S3, activation, is also included: the material obtained in step S2 is reduced in a hydrogen atmosphere at 300℃-350℃ for 1-2 hours to obtain a material containing Fe. 2+ K2O / Fe3O4 / CaO / ZnO / carbon composite material.

[0155] In this embodiment, it should be noted that step S3 is optional; if it is necessary to strengthen Fe... 2+ The reduction function is recommended to be added; this step is suggested to reduce the amount of Fe after reduction. 3+ Converted to Fe 2+ It can significantly improve the resistance to Cr 6+ The reduction capacity should be limited; the reduction temperature should not exceed 350℃, otherwise it may lead to excessive reduction of iron ions to metallic Fe, reducing catalytic activity.

[0156] The method for preparing the carrier in step S1 is as follows:

[0157] S001. Coal powder and enzymatically hydrolyzed lignin powder are mixed at a ratio of 10:1 to 5:1 and subjected to supercritical carbon dioxide dynamic cyclic pyrolysis at 280℃-320℃ and 8MPa-20MPa to obtain lignin-semi-coke composite carbon skeleton powder.

[0158] S002. Add the carbon skeleton powder to an alkaline solution (KOH, NaOH or Ca(OH)2 solution), heat and stir, then separate by density difference flotation and collect the upper effective component.

[0159] S003. Granulation and molding: The upper effective components are collected by calcining in an inert atmosphere at 300℃-500℃ using ball rolling granulation, extrusion granulation or spray granulation to obtain porous carbon particle carriers with particle size controlled at 2mm-10mm.

[0160] It should be added that the dynamic cyclic pyrolysis of critical carbon dioxide can promote the interfacial chemical bonding between lignin and coal powder, forming a continuous structure without interfaces; alkaline flotation can remove unreacted minerals and low-activity components, and increase the specific surface area and mesopore ratio of the carrier.

[0161] The technical effects achieved in this embodiment are as follows: the carrier prepared by supercritical carbon dioxide dynamic pyrolysis has a continuous carbon skeleton without interface, combining rigidity and flexibility, and has high mechanical strength; the pore structure can be precisely controlled by alkaline flotation, and the proportion of mesopores can be controlled between 40% and 60%; the formed particles have uniform size and controllable pressure drop, and are suitable for industrial fixed bed and fluidized bed reactors.

[0162] Example 5

[0163] This embodiment uses the method described in Example 4 to prepare a continuous carbon framework support. The specific method is as follows:

[0164] Take 500g of bituminous coal powder and add 75g (15%) of enzymatically hydrolyzed lignin powder, mix well. Place the mixture into a supercritical reactor, introduce CO2, heat to 300℃, pressurize to 15MPa, add 2% (by weight of coal powder) of n-hexane as a co-solvent, start the circulating compressor, and dynamically circulate the reaction for 2 hours. Depressurize and cool, collect the lignin-semi-coke composite carbon skeleton powder.

[0165] Take 100 g of the above powder, add 300 mL of 1.5 mol / L KOH solution, heat to 90℃ and stir for 40 minutes, allow to stand and float to separate, and collect the upper effective component. Granulate using a ball granulator, control the particle size to 2 mm-5 mm, dry at 110℃ for 4 hours, and calcine at 450℃ under nitrogen atmosphere for 3 hours to obtain continuous carbon framework support particles.

[0166] The carrier's performance, as tested, is as follows: specific surface area 372 m². 2 / g, mesoporous ratio 40%, thermal conductivity 85 W / (m·K), lateral compressive strength 95 N.

[0167] Example 6

[0168] This embodiment uses the method described in Example 3 to load the main component. The specific method is as follows:

[0169] Take 100g of the carrier prepared in Example 5, immerse it in 150mL of mixed solution (1.0mol / L ferric acetate + 0.5mol / L calcium acetate + 0.3mol / L zinc acetate), stir and impregnate at 80℃ for 2 hours, dry at 110℃ for 4 hours, and calcine at 450℃ under nitrogen atmosphere for 3 hours to obtain Fe2O3 / CaO / ZnO / carbon composite material.

[0170] Exhaust gas detection: Only CO2 and water vapor were detected in the outlet gas, with no NO. X .

[0171] The test results showed that the Fe2O3 / CaO / ZnO / carbon composite material contained 17.8% Fe2O3, 11.5% CaO, and 4.0% ZnO.

[0172] Example 7

[0173] This embodiment uses the method described in Example 3 to load the excipient, and the specific method is as follows:

[0174] The material prepared in Example 6 was immersed in 100 mL of 0.5 mol / L KOH solution, stirred and impregnated at 80°C for 1 hour, dried at 110°C for 4 hours, and calcined at 350°C under nitrogen atmosphere for 2 hours to obtain the K2O / Fe2O3 / CaO / ZnO / carbon composite material.

[0175] The K2O content was found to be 5.2%.

[0176] Example 8

[0177] This embodiment uses the material prepared in Example 7 to perform integrated gasification-adsorption testing. The specific method is as follows:

[0178] The material prepared in Example 7 was mixed with municipal solid waste at 3% of the raw material mass and fed into a gasifier. Gasification conditions: temperature 700℃, water vapor gasification, oxygen 5%, reaction time 45 minutes.

[0179] The test results are shown in Table 1 below.

[0180] Table 1

[0181]

[0182] Example 9

[0183] In this embodiment, the material prepared in Example 7 was used to test the Fischer-Tropsch synthesis performance. The specific method is as follows:

[0184] Take 5g of the material prepared in Example 7 and pack it into a fixed-bed reactor. Syngas (H2:CO = 2:1) is introduced, the reaction temperature is 300℃, the pressure is 2.0 MPa, and the space velocity is 2000 h⁻¹. -1 .

[0185] The test results are as follows:

[0186] CO conversion rate: 68%;

[0187] C5-C 18 Selectivity: 72% (of which gasoline is 45%, aviation kerosene is 20%, and diesel is 7%).

[0188] C 19 + Wax selectivity: 2%;

[0189] C2-C4 olefin selectivity: 12%;

[0190] Example 10

[0191] This embodiment uses the material prepared in Example 7 to test its tar pyrolysis performance. The specific method is as follows:

[0192] Take 5g of the material prepared in Example 7 and pack it into a fixed-bed reactor. Purge with simulated tar gas (naphthalene 5000ppm, H2O 20%, N2 equilibrium) at a space velocity of 5000 h⁻¹. -1 The reaction temperature is 700℃.

[0193] The test results are as follows: naphthalene conversion rate 92%, CO selectivity 85%, H2 selectivity 82%.

[0194] Example 11

[0195] This embodiment uses the material prepared in Example 7 to conduct a heavy metal wastewater treatment-mixed solution test. The specific method is as follows:

[0196] Take 0.5g of the material prepared in Example 7 and add it to 100 mL of Pb-containing solution. 2+ Concentration 100 mg / L, Cd 2+ Concentration 50 mg / L, Hg 2+ Concentration 10 mg / L, As 3+ Concentration 10 mg / L, Cr 6+ In a mixed solution with a concentration of 50 mg / L, the mixture was stirred at 25°C for 2 hours and then separated using an external magnetic field.

[0197] The test results are shown in Table 2 below.

[0198] Table 2

[0199]

[0200] Magnetic separation: With an external magnetic field of 0.5 T, the separation and recovery rate is 98.5% after 5 minutes.

[0201] Example 12

[0202] This embodiment uses the material prepared in Example 7 for magnetic separation and recovery testing. The specific method is as follows:

[0203] Take 5g of the material prepared in Example 7 and add it to 500 mL of Pb-containing solution. 2+ In the solution, after adsorption saturation, an external magnetic field of 0.5T is applied.

[0204] Tests showed that the separation and recovery rate was 98.5% after 5 minutes, compared to only 65% ​​after 30 minutes of natural sedimentation without a magnetic field.

[0205] Example 13

[0206] This embodiment uses the material prepared in Example 7 to conduct soil heavy metal remediation tests. The specific method is as follows:

[0207] A Pb- and Cd-contaminated soil sample (Pb content 450 mg / kg, Cd content 8.5 mg / kg, pH=5.2) was taken, and the material prepared in Example 7 was added at 3% of the soil mass. The mixture was thoroughly mixed, kept at a moisture content of 30%, and cured for 28 days, turning it over every 7 days during this period. After the curing period, the leaching concentration of heavy metals was determined using the TCLP method, and the material was recovered by magnetic separation using an external magnetic field.

[0208] The test results are shown in Table 3 below.

[0209] Table 3

[0210]

[0211] Conclusion: The leaching concentration of heavy metals in the treated soil meets the standard of GB 5085.3-2007, and the material can be recovered through magnetic separation, realizing soil purification and material recycling.

[0212] Example 14

[0213] This embodiment is used for performance comparison of carriers with different particle sizes. The specific method is as follows:

[0214] The carrier from Example 5 was granulated to particle sizes of 1 mm, 3 mm, 5 mm, and 8 mm, respectively. Materials were prepared according to the methods in Examples 3 and 4, and gasification tests were performed according to the method in Example 8. The results are shown in Table 4 below.

[0215] Table 4

[0216]

[0217] Example 15

[0218] This embodiment compares the environmental friendliness and main component loading of different precursors (acetate (ferric acetate + calcium acetate + zinc acetate) and nitrate (ferric nitrate + calcium nitrate + zinc nitrate)). When using acetate for loading, the loading method in Example 3 is followed. When using nitrate for loading, the loading method is the same as in Example 3 (the concentration is the same, the difference is that nitrate is used instead of acetate). After loading, the results are shown in Table 5 below.

[0219] Table 5

[0220]

[0221] Example 16

[0222] This embodiment is used for multi-component synergistic comparison. The specific testing method is the one described in Example 8. The comparison results are shown in Table 6 below.

[0223] Table 6

[0224]

[0225] Example 17

[0226] The application of a multi-component gasification-adsorption bifunctional material with iron and calcium as the main agent in gasification reaction involves mixing the material with the gasification feedstock and feeding it into a gasifier for gasification reaction at 650℃-750℃, simultaneously achieving tar cracking, Fischer-Tropsch synthesis and heavy metal stabilization.

[0227] In this embodiment, it should be noted that the gasification feedstock includes, but is not limited to, municipal solid waste, biomass, sludge, coal and their mixtures; the gasification agent may be air, water vapor, oxygen-enriched materials or a combination thereof.

[0228] Example 18

[0229] An application of a multi-component gasification-adsorption bifunctional material with iron and calcium as the main agents in wastewater treatment involves adding the material to wastewater containing heavy metals, including Pb. 2+ Cd 2+ Hg 2+ As 3+ Cr 6+ One or more of the following are used, with a solid-liquid ratio of 1:50-1:500, a stirring speed of 100 rpm-500 rpm, a treatment temperature of 10℃-80℃, and separation and recovery by applying an external magnetic field (0.3T-1.0 T) after adsorption.

[0230] Example 19

[0231] The application of a multi-component gasification-adsorption dual-function material with iron and calcium as the main agent in soil remediation involves mixing the material with heavy metal contaminated soil at a ratio of 1%-5% (by mass), curing for 7-30 days while maintaining a soil moisture content of 20%-40%, and turning the mixture every 3-7 days during the curing period. This process converts the migratable heavy metals into a stable state, and the material is then recovered by magnetic separation after treatment.

[0232] Application Example 1

[0233] This application example applies the gasification-adsorption bifunctional material from Embodiment 2 of the present invention to an integrated gasification-Fischer-Tropsch synthesis process. The specific application process is as follows:

[0234] The gasification-adsorption bifunctional material from Example 2 of this invention is mixed with gasification feedstock (municipal solid waste, biomass, sludge, coal) at a blending ratio of 1%-5% and fed into the gasification reactor. Utilizing the natural temperature gradient along the reactor's height, the following multi-step catalytic reaction is achieved:

[0235] (1) Bottom of gasifier (650℃-750℃)

[0236] Gasification reaction: C + H₂O → CO + H₂, endothermic, can be partially oxidized by introducing oxygen to provide energy;

[0237] Heavy metal stabilization: CaO, ZnO, and Fe2O3 react with Pb, Cd, Hg, As, and Cr to form stable compounds;

[0238] (2) Middle part of the gasifier (500℃-700℃)

[0239] Tar pyrolysis: C m H m +nH2O→nCO+(n+m / 2)H2, catalyzed by iron;

[0240] Water-gas shift reaction: CO + H2O → CO2 + H2, releasing heat and replenishing some heat;

[0241] It can reduce tar content by more than 80%;

[0242] (3) Upper settling space of gasifier (200℃-350℃)

[0243] Fischer-Tropsch synthesis: CO + 2H2 → -CH2- + H2O, strongly exothermic, -165 kJ / mol;

[0244] The product is gasoline (C5-C) 11 Aviation kerosene (C8-C) 16 ), diesel (C) 12 -C 18 The main process is to utilize natural cooling (heat is carried away by rising gas) and maintain its own temperature through exothermic reaction.

[0245] (4) Catalyst (i.e., the gasification-adsorption dual-functional material in this invention) circulation

[0246] The catalyst powder rises with the airflow, completes the Fischer-Tropsch synthesis in the settling space, and then naturally settles back to the bottom, achieving automatic recycling.

[0247] This application example employs an integrated reactor design, which offers the following advantages:

[0248] 1. The natural temperature gradient along the height of the gasifier can be utilized to achieve gasification, tar cracking, and Fischer-Tropsch synthesis relay catalysis in the same reactor;

[0249] 2. No downstream Fischer-Tropsch synthesis reactor is required, reducing equipment investment by 40%;

[0250] 3. It can utilize heat in a cascade manner: the heat endothermic by gasification is provided by partial oxidation, the heat endothermic by tar cracking is provided by rising hot gas flow, and the heat exothermic by Fischer-Tropsch synthesis is self-sustaining;

[0251] 4. The fine catalyst powder rises with the airflow, settles back to the bottom after the reaction, and is automatically circulated.

[0252] Application Example 2

[0253] This application example applies the gasification-adsorption bifunctional material from Embodiment 2 of the present invention to an integrated gasification-adsorption process, as follows:

[0254] The gasification-adsorption dual-functional material in Example 2 of this invention is mixed with gasification raw materials at a ratio of 1%-5% and fed into a gasification furnace. The gasification temperature is 650℃-750℃, the gasification agent is air, water vapor or oxygen-enriched, and the reaction time is 30min-60min. The final product is high-quality syngas (containing olefins) + stabilized ash residue. The leaching toxicity of the ash residue meets environmental protection requirements.

[0255] Application Example 3

[0256] This application example applies the gasification-adsorption bifunctional material from Embodiment 2 of the present invention to wastewater treatment. The specific application process is as follows:

[0257] In Example 2 of this invention, the gasification-adsorption dual-functional material is added to the wastewater to be treated, with a solid-liquid ratio of 1:50-1:500, stirred for 0.5-3 hours at a stirring speed of 100-500 rpm, and treated at a temperature of 10℃-80℃. After adsorption saturation, the material can be separated and recovered by applying an external magnetic field (0.3T-1.0T).

[0258] Application Example 4

[0259] This application example applies the gasification-adsorption dual-functional material from Embodiment 2 of the present invention to soil remediation. The specific application process is as follows:

[0260] The gasification-adsorption dual-function material in Example 2 of this invention is mixed with heavy metal contaminated soil at a mixing ratio of 1%-5%, and stirred evenly to maintain a soil moisture content of 20%-40%. The soil is then cured for 7-30 days, with regular stirring during the curing period (once every 3-7 days). After curing, a magnetic separator (drum or belt type) can be used for magnetic separation with a magnetic field strength of 0.5 T-1.0 T and 1-3 magnetic separations. The material recovery rate can reach over 98%.

[0261] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A multi-component gasification-adsorption dual-functional material with iron and calcium as the main agent, characterized in that, The product includes a carrier, a main component, and an excipient, wherein the carrier is porous carbon, and the main component and the excipient are both loaded on the carrier; The main components include iron-based oxides, CaO, and ZnO, with loadings of 15%-25%, 10%-20%, and 3%-8%, respectively. The excipient is a potassium-based oxide, and the loading of the excipient is 3%-8%.

2. The iron-calcium main formulation multi-component gasification-adsorption dual-functional material according to claim 1, characterized in that, The iron-based oxides include Fe2O3 and Fe3O4, and the auxiliary agent is K2O.

3. The iron-calcium main agent type multi-component gasification-adsorption dual-functional material according to claim 1, characterized in that, The porous carbon is a lignin-semi-coke composite porous material with a specific surface area of ​​200 m². 2 / g-500m 2 / g, with a mesopore size of 5nm-50nm, a mesopore ratio of >40%, a thermal conductivity of >50 W / (m·K), a compressive strength of >80N, and a surface oxygen-containing functional group content of 1mmol / g-3mmol / g.

4. The iron-calcium main agent type multi-component gasification-adsorption dual-functional material according to claim 1, characterized in that, The material is shaped granules with a particle size of 2mm-10mm.

5. A method for preparing a multi-component gasification-adsorption bifunctional material with iron and calcium as the main agent, used to prepare the material according to any one of claims 1 to 4, characterized in that, The specific steps include the following: S1. Loading of main agent components: Loading the main agent components onto the carrier using the impregnation method, including the following specific sub-steps: S101. Immerse the carrier in a mixed solution of ferric acetate, calcium acetate and zinc acetate for 0.5h-2h. S102, Remove and dry; S103, calcined in an inert gas atmosphere, yields Fe2O3 / CaO / ZnO / carbon composite material; S2, Excipient Loading: Excipients are loaded using the impregnation method.

6. The preparation method of a multi-component gasification-adsorption bifunctional material with iron and calcium as the main agent according to claim 5, characterized in that, Step S2 includes the following specific sub-steps: S201. Immerse the material obtained in step S1 in KOH solution for 0.5h-2h. S202, Remove and dry; S2O3 was calcined at 300℃-400℃ in an inert gas atmosphere for 1-3 hours to obtain a K2O / Fe2O3 / CaO / ZnO / carbon composite material.

7. The preparation method of a multi-component gasification-adsorption bifunctional material with iron and calcium as the main agent according to claim 6, characterized in that, In step S101, the concentration of ferric acetate is 0.5 mol / L-1.5 mol / L, the concentration of calcium acetate is 0.2 mol / L-1.0 mol / L, and the concentration of zinc acetate is 0.1 mol / L-0.5 mol / L. The drying temperature in step S102 is 80℃-120℃, and the drying time is 2h-6h; The calcination temperature in step S103 is 400℃-500℃, and the calcination time is 2h-4h; In step S201, the concentration of KOH is 0.2 mol / L - 1.0 mol / L; The drying temperature in step S202 is 80℃-120℃, and the drying time is 2h-6h.

8. The preparation method of a multi-component gasification-adsorption bifunctional material with iron and calcium as the main agent according to claim 5, characterized in that, The process also includes step S3, activation: reducing the material obtained in step S2 under a hydrogen atmosphere at 300℃-350℃ for 1-2 hours to obtain a material containing Fe. 2+ K2O / Fe3O4 / CaO / ZnO / carbon composite material.

9. The preparation method of a multi-component gasification-adsorption bifunctional material with iron and calcium as the main agent according to claim 5, characterized in that, The method for preparing the carrier in step S1 is as follows: S001. Coal powder and enzymatically hydrolyzed lignin powder are mixed at a ratio of 10:1 to 5:1 and subjected to supercritical carbon dioxide dynamic cyclic pyrolysis at 280℃-320℃ and 8MPa-20MPa to obtain lignin-semi-coke composite carbon skeleton powder. S002. Add carbon skeleton powder to alkaline solution, heat and stir, then use density difference to separate by flotation and collect the upper effective component; S003, Granulation: The collected upper effective components are calcined in an inert atmosphere at 300℃-500℃ to obtain porous carbon particle carriers.

10. The application of a multi-component gasification-adsorption dual-functional material with iron and calcium as the main formulation according to any one of claims 1 to 4 in gasification reaction, wastewater treatment or soil remediation.

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