41results about How to "Lower the desorption temperature" patented technology

The invention relates to a preparation method of a organic-inorganic porous composite material for absorbing carbon dioxide, which comprises the following steps: adding hydrogen-containing methyl polysiloxane into anhydrous ethanol, adding alkaline solution, mixing for 20-24 hours, adding deionized water into the solution, mixing for 0.5-5 hour(s), adding ethyl orthosilicate, mixing for 1-6 hour(s) to obtaining Solution A, dissolving organic amine into ethanol, mixing for 1-3 hour(s) to obtaining Solution B, adding the Solution B into the Solution A, mixing 3-5 hours, keeping static and aging for 3-5 days to obtain gel, and drying the gel for 24-30 hours at the temperature of 80-100 DEG C to remove ethanol in the system, thereby obtaining the organic-inorganic porous composite material. The invention has the advantages of low desorption temperature and high adsorption capacity. Simultaneously, the invention needs no template removing agent, thereby saving the cost and achieving good thermal stability.

The invention discloses a complex function resin and process for preparation, and a method used for dealing with phthalate ester water body pollution. The process for preparation comprises the following procedures: swelling chlorine ball in the organic solvent; sulfonating in the mixing condition; getting the sulfonated chlorine ball after reacting; charging nitrobenzene or o-dichlorobenzene in order to swell in the air-tight condition after drying the sulfonated chorine ball; charging the accelerant in order to react; filtering the resin; washing the resin sequentially with distilled water, alcohol and chlorhydric acid 2%-5%; washing the resin with the distilled water until the washed water is neutral; getting the complex function resin. The specific surface area of the complex function resin is 900-1500m2 / g, the exchange capacity of corrosive acid is 2.1-5.5mmol / g, and the sulfonic group is distributed in the micropore section, the mesopore section and the big pore section of the resin. The complex function resin is applied to deal with water body polluted by phthalate ester. The invention solves the problem that the corrosive acid of the prior complex function resin is concentrated in the mescopore and the big pore of the resin and is distributed less in the micropore, which enhances the absorption effect of the resin for phthalate ester, and enhances the acid hydrolysis catalytic activity of the resin.

The invention discloses an absorbent for ethylene efficiently separated from the gas with a light concentration of ethylene and a preparation method thereof. The absorbent is one or two metals supported on a molecular sieve and the composition of the absorbent is expressed by M-Z; Z symbolizes the molecular sieve and M is one or two selected from Ca, Ba, Sr, Ni, Co and Cu, and the weight percentage of M ranges from 10 per cent to 25 per cent; the absorbent possesses a high absorption capacity selectivity over the ethylene and the absorption capacity of the ethylene is higher than 3mmol / g under the suitable absorption conditions; the desorption temperature of the absorbent is low and the concentration of the ethylene in the desorption gas is high and the absorbent is suitable for the transformation absorption experiment equipment and is easy to be industrialized.

There is provided a sample preconcentrator. The sample preconcentrator in which a sample gas injection port is coupled to a dried gas supply source and a gas analysis system to concentrate a sample gas comprises a sample concentrating unit containing an absorbent that is composed of carbon nanotube-metal nanocomplexes; a conduit switching valve for selectively coupling the sample gas injection port to the dried gas supply source and the gas analysis system and controlling the absorption and desorption of the sample gas from the sample concentrating unit; and a plurality of conduits for connecting the sample gas injection port, the dried gas supply source, the gas analysis system, the sample concentrating unit and the conduit switching valve.

The invention discloses a garden landscape plant cultivation fertilizer which comprises the following raw materials in parts by weight: 10-20 parts of peat soil, 12-20 parts of chernozem, 12-20 parts of kieselguhr, 8-14 parts of plant ash, 8-14 parts of sawdust, 10-16 parts of vermiculite, 6-10 parts of a traditional Chinese medicine dreg extract, 2-6 parts of urea, 3-7 parts of superphosphate, 2-6 parts of diammonium phosphate, 2-4 parts of potassium sulfate, 2-4 parts of magnesium sulfate, 1-2 parts of ferrous sulfate, 2-4 parts of calcium chloride, 2-4 parts of boric acid, 3-7 parts of an alga extract, 3-7 parts of chitin and 0.5-1 part of a microbial agent. Investigation on components of the garden landscape plant cultivation fertilizer shows by accident that the traditional Chinese medicine dreg extract, the chitin and the microbial agent take a synergistic effect into play and have a mutualism relationship with plants, so that effects of nitrogen fixation, phosphorus dissolution, potassium dissolution and plant growth promotion can be achieved, plants can be prevented from being damaged by pathogenic bacteria, the fertility of soil can be effectively improved, and the garden landscape plant cultivation fertilizer is applicable to fertilization of garden landscape plant cultivation.

The invention relates to the field of industrial tail gas treatment, and discloses a waste activated carbon regeneration method, which comprises the following steps: performing vacuum thermal desorption on waste activated carbon until the desorption rate of VOCs in the waste activated carbon reaches 90% or above; washing the waste activated carbon subjected to vacuum thermal desorption to obtain wet activated carbon, drying the wet activated carbon, roasting in a protective atmosphere, carbonizing in an atmosphere with the oxygen content of less than or equal to 1%, activating in a mixed atmosphere of water vapor and carbon dioxide, and cooling to obtain regenerated activated carbon. Before entering the activated carbon regeneration stage, the activated carbon is subjected to vacuum desorption by reducing the pressure. Compared with the traditional heating desorption, the addition of a vacuum desorption regeneration technology reduces the temperature required by desorption regeneration, generates less waste gas, and does not cause serious pollution to the atmosphere; the combination of the process enables the overall reaction temperature of the whole method to be lower, but the adsorption capacity and reuse frequency of the produced product are both improved.

The invention relates to a novel hydrogen storage material, namely a metal ion modified nitrogen-containing organic compound. The organic compound is in an ionic solid crystal form at a room temperature, and will release hydrogen gas when heated to a low temperature. The organic compound is prepared by subjecting a series of nitrogen-containing compounds such as amine, alcohol amine, amino acid, amidine, amide, hydrazide, carbamide, nitrogen-containing heterocycle, and the like, to carry out reactions with metals or metallic compounds such as metal hydrides, metal composite hydrides, organic metal compounds, inorganic metal salts, and the like, according to a certain ratio so as to obtain products substituted by corresponding metal ions. The ionic product with a certain structure can release hydrogen gas at a low temperature, and thus is a novel hydrogen storage material with a good application prospect.

The invention discloses a zeolite molecular sieve-heat conducting framework composite adsorbent and a preparation method. According to the method, raw materials for preparing a zeolite molecular sieve and heat-conducting framework materials are uniformly mixed to generate reaction gel, and the zeolite molecular sieve-heat conducting framework composite adsorbent is prepared by a hydrothermal crystallization method. The porous composite zeolite molecular sieve adsorbent is synthesized by a heat-conducting framework, so that the heat transfer capability of the composite adsorbent is improved, efficient heat transfer is ensured; the problems of high desorption temperature and low mass transfer efficiency of the zeolite molecular sieve are solved, the charge capacity of the zeolite molecular sieve in VOCs (Volatile Organic Compounds) adsorption and / desorption utilization efficiency are increased remarkably; moreover, the preparation method is simple and efficient, and is suitable for industrial large-scale production.

The invention discloses a biomass intelligent fiber-based amphoteric multifunctional adsorption material and a preparation method and application thereof. The material is obtained by taking stepped dual-temperature stimuli-responsive biomass intelligent fibers as a matrix and crown ether modified amphoteric hyperbranched polyamine as a functional reagent and directly carrying out one-step cross-linking compounding on the stepped dual-temperature stimuli-responsive biomass intelligent fibers and the crown ether modified amphoteric hyperbranched polyamine by adopting a cross-linking agent. The material has stepped dual-temperature stimuli responsiveness, high amino density (greater than 12 mmol / g), carboxyl density (greater than 5 mmol / g) and a nano cavity.

The invention relates to a rare-earth modified molecular-sieve dehumidification adsorbent paper sheet and a preparation method thereof. The preparation method comprises the following steps: soaking the powder molecular sieve in a solution containing acidic rare earth, carrying out ion exchange, filtering, drying and roasting to obtain the rare-earth modified molecular sieve; and dispersing the rare-earth modified molecular sieve in silicasol under the action of ultrasound to obtain a suspension, soaking ceramic fiber paper in the suspension, taking out after the ceramic fiber paper is completely moistened, airing and drying to obtain the rare-earth modified molecular-sieve dehumidification adsorbent paper sheet. The modified molecular-sieve paper sheet has the advantages of high adsorption capacity and low regeneration temperature, can be processed into honeycomb, and is suitable for adsorption-type rotating wheel dehumidification and heat recovery under the environmental conditions of different humidities and / or different temperatures.

The invention relates to a synergistic indirect thermal desorption soil remediation system and a remediation method thereof. The system comprises an alkali liquor spray feeding system, fed soil is sent to a rotary kiln type thermal desorption chamber after alkali liquor spray stirring, a combustion chamber produces high-temperature flue gas to provide heat to indirectly heat a rotary kiln, and organic matter is degraded to be desorbed from polluted soil under the synergistic effect of heating and alkali liquor catalysis; the thermal desorption chamber is provided with a desorption gas outlet connected with a tail gas treatment system, the tail gas treatment system performs spray cooling on thermal desorption gas to condensate and transfer organic matter to sewage, and one part of producedsewage is recycled and the other part is used for humidifying discharged materials after the sewage is sent to a sewage treatment purification system for purification. The synergistic indirect thermaldesorption soil remediation system can significantly improve the soil treatment capacity, effectively reduce thermal adsorption temperature of organic matter polluted soil and save energy consumption.

The invention belongs to the technical field of agricultural greenhouses, and specifically discloses a water self-supplying agricultural greenhouse system. The system includes an optical system disposed in the greenhouse, a water generating system disposed on one side of the optical system and a blower connected with the water generating system, wherein the optical system includes a Fresnel lens,a first concave lens disposed at the condensing point of the Fresnel lens and solar limited-frequency reflecting glass disposed under the first concave lens, and the water generating system comprisesan insulating layer, a selective absorbing coating and a moisture adsorbing layer; the moisture adsorbing layer includes a adsorbent material layer and a metal thermally conductive rod, and the insulating layer is transmissive to infrared light reflected by the solar limited-frequency reflecting glass. Through the system, gradient utilization of sunlight is realized, cleanness and environmental protection can be achieved, consumption of non-renewable energy is reduced, and meanwhile the water self-supplying function of the greenhouse can be achieved; in a water-deficient area, not only agricultural water can be provided, but also supplementing of domestic water can be achieved, so that the problem of water shortage is alleviated.

The invention discloses a preparation method of a modified Y-type molecular sieve. The preparation method is characterized in that a NaY molecular sieve, alkali and water are mixed in proportion, a water solution of the molecular sieve and alkali is beaten, and the molecular sieve is subjected to alkali treatment at the temperature of 80-120 DEG C for 5-24 h; the Y-type molecular sieve subjected to alkali treatment is subjected to ion exchange and then subjected to hydrothermal roasting at the temperature of 500-600 DEG C for 1-2 h, and the modified Y-type molecular sieve is obtained. Calcium ions are used for modifying the Y-type molecular sieve, a layer of calcium is formed on the surface of the molecular sieve through exchange of calcium and sodium, organic waste gas containing alcohol can be effectively adsorbed by means of the performance of a complex compound prepared from calcium ions and alcoholic hydroxyl groups, and the dissociation temperature of the complex compound is lower, so that the desorption temperature of the molecular sieve is reduced, and the energy consumption of an enterprise is reduced during treatment of waste gas.

A high-power-density activated carbon fibre adsorption bed controlled and intensified by electrostatic charges and used for the solid-adsorptive refrigerating system is composed of an adsorption core, a casing and a closure head. Said core has the electrostatic input for the controllable charging and discharging of electrostatic charges. When said adsorption bed is in adsorption state, the positive charges are charged onto the activated carbon fibre cloth for intensifying adsorption effect. When it is in desorption state, said positive charges are discharged for lowering the desorption temp.

The invention belongs to the technical field of agricultural greenhouses, and discloses an agricultural greenhouse self-water-supply system based on a fluidized bed. The system comprises an optical subsystem and a water making subsystem. The water making subsystem comprises a solar heat absorption plate of a hollow structure inside, the fluidized bed, a draught fan arranged at the other end of thesolar heat absorption plate, a condensing pipe arranged at the tail end of the fluidized bed, and a water collecting tank arranged at the lower end of the condensing pipe, wherein a water absorptionmaterial is arranged in the fluidized bed, the water collecting tank is connected with the draught fan through an air pipe, and then the whole water making subsystem forms a closed loop. The inventionfurther discloses a method corresponding to the system. By means of the mechanism that the energy of infrared light in solar light is used as the heat energy for dewatering an adsorption material anddesorbed water is converted into vapor to be collected, the problem that desorbed water cannot be sufficiently collected in existing problems is solved, and the agricultural greenhouse self-water-supply system has the advantages of being compact in structure, simple in operation process and high in solar energy utilization rate.

The invention discloses an aluminum foil-based aluminum-fumaric acid MOF adsorbent coating and a mixed solvent in-situ synthesis method and application thereof. The method comprises the following steps of: adding fumaric acid into nitrogen, nitrogen-dimethylformamide, adding aluminum salt into water, uniformly mixing the fumaric acid and the aluminum salt to obtain a mixed solution, and adjustingthe pH value to be acidic to obtain a uniform acidic reaction solution; and immersing an aluminum foil in the uniform acidic reaction solution, heating, taking out, washing, drying and activating to obtain the aluminum foil-based aluminum-fumaric acid MOF adsorbent coating. The aluminum foil-based aluminum-fumaric acid MOF adsorbent coating prepared by the invention is adjustable in thickness, isuniformly and densely distributed on the aluminum foil, and is high in bonding strength with a base material; the adsorbent coating has the characteristics of strong adsorption capacity, high adsorption speed, low desorption temperature, good cycling stability and the like. The aluminum foil-based aluminum-fumaric acid MOF adsorbent coating can be used for adsorbent coated substrates useful in airhandling systems such as heating, ventilation, and air conditioning (HVAC), as well as adsorbent coated aluminum foil finned heat exchangers for adsorptive heat pump systems.

The invention relates to a new carbon-based adsorption material and a preparation method thereof, mainly solving the problem that an adsorption recovery material is poor in hydrophobicity, low in capacity of adsorbing target organic matter molecules, severe in difficulty of vacuum desorption, and low in adsorption / desorption rate in a high-humidity environment. According to the preparation method, resorcinol or m-trihydroxybenzene and gracial acetate acid are taken as reaction raw materials, a formaldehyde aqueous solution is taken as a reaction solvent, and the high-specific-surface-area carbon-based adsorption material is prepared through a process of sol gel freeze drying and carbonization activation, so that the problem is well solved. The new carbon-based adsorption material can be used in engineering material technology.

The invention relates to a chemical-thermal desorption combined remediation method for polycyclic aromatic hydrocarbon contaminated soil. The method comprises the following steps: 1, pretreatment of the contaminated soil: sequentially crushing, grinding and screening the polycyclic aromatic hydrocarbon contaminated soil, and then adjusting the moisture content of the soil to obtain a soil sample for later use; 2, chemical pre-oxidation treatment: adding an oxidizing agent into the soil sample by adopting a dry mixing method to carry out chemical pre-oxidation treatment; and 3, thermal desorption: performing thermal desorption treatment on the soil subjected to pre-oxidation treatment under a medium-temperature condition, and then cooling to room temperature. According to the method, the contaminated soil is pre-oxidized through the oxidizing agent containing benzoyl peroxide, then the PAHs contaminated soil is subjected to thermal desorption treatment, the PAHs removal efficiency can be improved, meanwhile, the remediation temperature can be reduced, and therefore the purposes of reducing remediation energy consumption and remediation cost are achieved.

The invention discloses a zeolite molecular sieve-heat conducting framework composite adsorbent and a preparation method. According to the method, raw materials for preparing a zeolite molecular sieve and heat-conducting framework materials are uniformly mixed to generate reaction gel, and the zeolite molecular sieve-heat conducting framework composite adsorbent is prepared by a hydrothermal crystallization method. The porous composite zeolite molecular sieve adsorbent is synthesized by a heat-conducting framework, so that the heat transfer capability of the composite adsorbent is improved, efficient heat transfer is ensured; the problems of high desorption temperature and low mass transfer efficiency of the zeolite molecular sieve are solved, the charge capacity of the zeolite molecular sieve in VOCs (Volatile Organic Compounds) adsorption and / desorption utilization efficiency are increased remarkably; moreover, the preparation method is simple and efficient, and is suitable for industrial large-scale production.

The invention discloses a preparation method of a high-load modified silica gel dehumidification rotary core, and belongs to the field of dehumidification material preparation. The method comprises the following steps of: (1) drying and purging a sample block of the dehumidification rotary core, then soaking the sample block in water glass, and then purging the sample block with hot air; (2) repeatedly and uniformly spraying the residual water glass in the step (1) onto the sample block obtained in the step (1), and then purging the sample block with hot air; (3) soaking the sample block obtained in the step (2) in a zinc salt solution in a water bath, and adjusting the pH value to an initial pH value by using acid in the reaction process; and (4) washing the sample block obtained in the step (3) with water until the sample block is neutral, and roasting and drying the sample block. According to the method, the modified silica gel dehumidification rotary core which is large in effective load capacity, good in adsorption performance and high in mechanical strength is obtained through twice dipping and metal doping process control.

The invention particularly relates to a distributed hydrogen production energy storage power generation system and a working method thereof.The system comprises a water electrolysis hydrogen production unit, a hydrogen purification and humidification unit, a fuel cell power generation unit and a solid hydrogen storage unit, and the water electrolysis hydrogen production unit is connected with the hydrogen purification and humidification unit through a pipeline; the hydrogen purification and humidification unit is respectively connected with the fuel cell power generation unit and the solid hydrogen storage unit through pipelines, and the fuel cell power generation unit is connected with the water electrolysis hydrogen production unit through a pipeline. The working method comprises a hydrogen production-hydrogen storage mode, a drying tower regeneration mode and a hydrogen storage-power generation mode. The drying tower of the hydrogen purification and humidification unit is coupled with the fuel cell power generation unit, efficient utilization of water and energy is achieved, and the system is high in safety and stability.

The invention provides a trace nickel composite layered magnesium composite material as well as a preparation method and application thereof, and relates to the technical field of composite materials. The invention provides a trace nickel composite layered magnesium composite material. The trace nickel composite layered magnesium composite material comprises a nanometer layered magnesium matrix and nanometer nickel distributed on the surface and between layers of the nanometer layered magnesium matrix. The trace nickel composite layered magnesium composite material provided by the invention has relatively high hydrogen storage capacity, high hydrogen absorption and desorption efficiency and good cycle stability.

The invention relates to a multi-element transition metal-doped metal silicoaluminophosphate molecular sieve and a preparation method thereof, wherein the metal atoms are at least two of vanadium, copper, molybdenum, cobalt, manganese, magnesium, iron, nickel and zinc, etc., And at least one of copper, iron and nickel is contained. The high-purity product was prepared by one-step hydrothermal reaction, and its anhydrous composition can be expressed as: mR·nMe·(Si x Al y P z )O 2 , where R is the template agent in the molecular sieve, m is per mole (Si x Al y P z )O 2 Contains the molar amount of the template agent, m=0.15-0.45; Me is the metal in the molecular sieve framework, and n is each mole (Si x Al y P z )O 2 The total molar amount of contained metals, n=0.01‑0.2, where each transition metal is relative to each mole (Si x Al y P z )O 2 The ratio is between 0.0001‑0.2. The synthesized metal silicoaluminophosphate molecular sieve has excellent adsorption performance, and the catalyst made from it can be applied to olefin synthesis and SCR denitration reaction.

The invention discloses a catalyst-loaded organic-contaminated soil thermal desorption circulating medium and a preparation method thereof. Microporous ceramics are used as a circulating body, and 5-20% of Co-Ca-K@Fe is loaded. 3 O 4 catalyst. The calcium potassium cobalt composite oxide is the catalytic active component, the citric acid is the carrier complexing agent, the nano ferric oxide particles are the carrier, and the sodium lauryl sulfate is the circulating medium dispersant. Based on the quality of the carrier, the mass percentage of the catalytically active components is 5% to 15%. The iron salt, citric acid and active component precursor solution were added into the polytetrafluoroethylene hydrothermal reactor, and Co‑Ca‑K@Fe was prepared by hydrothermal, drying and roasting 3 O 4 catalyst. The circulating medium can simultaneously catalyze and oxidize organic pollutants in the process of soil thermal desorption, decompose them into water, carbon dioxide, etc., and release heat, and can be recycled during the thermal desorption process; after a period of use, the thermal medium will It is worn and broken, and the catalytic material also loses its activity and decomposes into calcium oxide, potassium salt and other beneficial components that can improve the soil.

The invention provides a carbon-based porous material and its preparation method and application. The preparation method of the carbon-based porous material includes the following steps: (A) Mixing carbon powder, starter and water evenly and then fermenting; (B) Mixing the fermentation product with water and a binder and then cross-linking and solidifying; (C) Shape and dry the product obtained by cross-linking and solidification; (D) Carbonize and activate the dried product. The surface of the carbon-based porous material provided by the invention has a penetrating hierarchical pore structure, with macropores inside mesopores and mesopores inside micropores. The mesopore content is high, which shortens the diffusion distance of organic gas molecules during the adsorption process. At the same time, It can also accelerate the adsorption and desorption rate and reduce the desorption temperature. It can also help solve the problem of desorption and recovery of organic gas molecules. The new carbon-based porous material prepared by the present invention is a low-cost, high-performance product, which is particularly suitable for oil and gas recovery, water treatment, catalyst carrier and other fields, and has good industrial application prospects and high socio-economic value.

The invention discloses an in-situ synthesis method and application of an aluminum foil-based aluminum-fumaric acid MOF adsorbent coating and a mixed solvent thereof. The method comprises: adding fumaric acid to nitrogen, nitrogen-dimethylformamide, adding aluminum salt to water, mixing the two evenly to obtain a mixed solution, adjusting the pH to be acidic to obtain a uniform acidic reaction solution; immersing the aluminum foil In the uniform acidic reaction solution, heat treatment, take out, wash, dry and activate to obtain the aluminum foil-based aluminum-fumaric acid MOF adsorbent coating. The aluminum foil-based aluminum-fumaric acid MOF adsorbent coating prepared by the invention has adjustable thickness, uniform and dense distribution on the aluminum foil, and high bonding strength with the substrate; the adsorbent coating has strong adsorption capacity, fast adsorption speed, and desorption. Low temperature, good cycle stability and so on. It can be used in adsorbent-coated substrates for air handling systems such as heating, ventilation and air conditioning (HVAC), and in adsorbent-coated aluminum foil fin heat exchangers for adsorption heat pump systems.

The invention discloses a method for utilizing surface functional group to intensify the regeneration performance of adsorption resin. The method comprises the following steps: (A), respectively adjusting the pH value of industrial waste water containing alkali organic substance to the pKb of the alkali organic substance at 25 DEG C and then carrying out filtration to eliminate suspended substances in the waste water; (B), ensuring that obtained filtrate passes through an adsorption tower filled with alkali composite functional adsorption resin; and (C), stopping adsorption when adsorption reaches a leakage point and taking dilute hydrochloric acid and dilute sulphuric acid as a desorption agent to desorb the alkali composite functional adsorption resin. The method does not influence adsorption performance and intensifies the regeneration performance of adsorption resin, thereby reducing the dosage of desorption agent, lowering desorption temperature and saving operation cost; therefore, the method is of great significance to the application and popularization of resin adsorption technology.

The invention proposes a method for processing a silicon-based substrate, comprising: obtaining a silicon wafer; chemically treating the silicon wafer to form a hydrogen passivation layer on the surface of the silicon wafer; performing a desorption process on the silicon wafer to remove hydrogen passivation layer. According to the silicon-based substrate processing method of the embodiment of the present invention, after the silicon wafer is chemically treated, a hydrogen passivation layer is formed on the surface of the silicon wafer, which can effectively protect the silicon wafer. Moreover, the desorption temperature of the hydrogen passivation layer is relatively low, thereby effectively reducing the problem of bending damage and introducing impurities caused by the high-temperature desorption of the passivation layer on the silicon wafer. Moreover, when selecting a silicon wafer, optimize the silicon Chip screening standards, thereby effectively reducing the flatness of silicon-based substrates, improving the processing quality of silicon-based substrates, and facilitating the processing of large area array devices.

The invention discloses a catalyst-loaded organic matter contaminated soil thermal desorption circulating medium and a preparation method thereof. Microporous ceramic is used as a circulating body, and 5-20% of a Co-Ca-K@Fe3O4 catalyst is loaded. The calcium-potassium-cobalt composite oxide is a catalytic active component, the citric acid is a carrier complexing agent, the nano ferroferric oxide particles are carriers, and the lauryl sodium sulfate is a circulating medium dispersing agent. On the basis of the mass of the carrier, the mass percentage of the catalytic active component is 5-15%. The preparation method comprises the following steps: adding ferric salt, citric acid and an active component precursor solution into a polytetrafluoroethylene hydrothermal reaction kettle, and carrying out hydrothermal treatment, drying and roasting to obtain the Co-Ca-K@Fe3O4 catalyst. The circulating medium can synchronously catalyze and oxidize organic pollutants in the soil thermal desorption process, decompose the organic pollutants into water, carbon dioxide and the like and release heat, and can be recycled in the thermal desorption process; after being used for a period of time, the thermal medium can be abraded and broken, and the catalytic material also loses activity and is decomposed into beneficial components such as calcium oxide and potassium salt which have an improvement effect on soil.