589 results about "Hydrothermal carbonization" patented technology

The present invention discloses a nitrogen-doped porous carbon material preparation method, which comprises: adopting nitrogen-containing macromolecule as a template agent and a nitrogen source, adopting a biomass derivative as a carbon source, carrying out a hydrothermal carbonization reaction under a hydrothermal condition, and removing the template agent to obtain the nitrogen-doped porous carbon material. The present invention further provides a class of nitrogen-doped porous carbon materials prepared by using the method. The material obtained through the preparation method has characteristics of high nitrogen content and relatively high specific surface area. Experiment results show that the nitrogen-doped porous carbon materials provide excellent absorption performances for hydrogen and carbon dioxide. In addition, due to presence of the nitrogen-containing group, the porous material of the present invention can be expected to be used for catalysis, gas storage, molecule separation, clean energy carriers, super capacitors and other fields.

The invention relates to a preparation method of biomass-based magnetic biochar. According to the preparation method, forestry and agricultural waste materials are taken as raw materials; biochar prepared via oxygen-limited pyrolysis or hydrothermal carbonization is taken as a substrate; magnetic nano-material Fe3O4 is obtained via iron precursor pyrolysis, loading of magnetic nano-material Fe3O4 onto the biochar substrate is realized in a polyhydric alcohol solution, and an obtained product is subjected to sintering under nitrogen protection so as to obtain stable magnetic nano particles with high crystallinity. Compared with existing technology, loading of in-situ synthesized Fe3O4 onto the surface of biochar is realized via pyrolysis; reaction selectivity and efficiency are high; size of the Fe3O4 nano particles and loading area on the surface of biochar are controllable; and operation is simple and convenient.

The invention relates to a treatment method of sludge generated by urban sewage treatment plant and industrial sludge and discloses a sludge treatment method based on hydrothermal carbonization. The sludge treatment method comprises four steps: sludge preheating treatment, hydrothermal carbonization, waste heat recovery and dehydration desiccation. By adopting the sludge treatment method, as the sludge is converted to hydrothermal carbon by adopting a hydrothermal carbonization technology, pathogenic microorganisms in the sludge are completely killed, most heavy metal pollutants in the sludge are dissolved out, and organic toxic substances in the sludge are effectively decomposed, so that the energy recovery utilization rate is high, and the sludge treatment method is clean, environment-friendly, rapid and effective and has high product additional values.

The preset invention is a hierarchically-structured carbon microbead and method for forming the microbead utilizing hydrothermal carbonization of a biomass / catalyst mixture to produce partially carbonized amorphous microspheres, wherein the biomass is an inexpensive material containing a high oxygen content component (e.g., sugar, starch, alcohol), and the catalyst is a metal or metal-containing compound, preferably a transition metal compound, and more specifically a transition metal selected from Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, and Pt. Subsequently, a heat treatment is performed where the amorphous microspheres are heated to a temperature that is sufficiently high so as to result in carbonization, graphitization, and production of a carbonaceous coating or shell on the core of the microbead.

The invention provides a preparation method of a biomass carbon composite material for removing phosphorus in wastewater. The preparation method comprises the steps of adding waste biomass into a metal salt solution to stir and mix evenly, then adding an alkali solution to continuously stir for 30-120 minutes, then performing hydrothermal carbonization, cooling a product to room temperature after reaction is ended, filtering, washing unreacted substances on the surface by using water and / or ethyl alcohol, then drying to constant weight at a temperature of 60-120 DEG C and sieving through a sieve with 40-180 meshes to obtain the biomass carbon composite material. According to the preparation method, the waste biomass serves as the raw material, so that the preparation method is low in cost; due to the adoption of hydrothermal carbonization, the preparation method is warm in reaction condition and simple in whole preparation process; and the prepared biomass carbon composite material is good in stability and efficient in phosphorus removal effect.

The invention discloses a method for preparing a biomass carbon-based composite energy storage material by utilizing plant fiber. Natural plant fiber such as straws, sawdust and cotton is subjected to mechanical pulverization and ultrasonication, and then conducts hydrothermal reaction with metal salt at 150-350 DEG C for 10-72 hours under an alkaline condition to synthesize in one step; or the plant fiber is subjected to hydrothermal carbonization in advance; then biomass carbon reacts with the corresponding metal salt, including the hydrothermal reaction; and the biomass carbon-based metal oxide and hydroxide composite material is synthesized in two steps. The electrochemical energy storage performance of the biomass carbon-based composite material prepared by the method is significantly improved compared with corresponding pure metal oxide and hydroxide.

The invention discloses a highly-graphitized carbon nanowire ball material and a preparation method thereof. An activated carbon material is prepared from carbohydrate used as a carbon source through hydrothermal and carbonization activation, the prepared activated carbon material is dipped in a metal salt catalyst solution and dried, a prepared dipped sample is treated at the high temperature under the protection of inert gas, and a graphitized carbon and metal composite is obtained; the obtained composite is treated with an acidic solution, washed, subjected to solid-liquid separation and dried, and the highly-graphitized carbon nanowire ball material is prepared. The wire ball is formed by winding carbon nanowires with the diameters of 10-100 nm, the diameter of the wire ball is 0.2-5 mu m, and the graphitization degree is 0.7-1. The highly-graphitized carbon nanowire ball material has the advantages of uniform dispersion, high graphitization degree, large specific surface area, low cost of raw materials, simple process, no pollution, easiness in industrial production and the like and has wide application prospect in the fields of electrochemical energy storage, adsorption separation, catalyst carriers, medicines and the like.

The invention provides a preparation method of a microalga-based biochar material for heavy metal ion adsorption. The preparation method comprises the following steps that 1, microalgae and water are added into a hydrothermal reaction kettle to prepare microalga suspension liquid; 2, organic acid is added into the microalga suspension liquid, and after the hydrothermal reaction kettle is sealed, protective gas is introduced into the hydrothermal reaction kettle to replace air in the hydrothermal reaction kettle; 3, the hydrothermal reaction kettle in the step 2 is placed in a drying oven for a carbonation reaction, and the microalga-based biochar material is obtained; 4, activating treatment is performed on the microalga-based biochar material, and the activated microalga-based biochar material is obtained. According to the preparation method, biochar is prepared through hydrothermal carbonization by taking the nitrogen-containing microalgae as the raw material, and then activated modification is performed on the biochar through a KOH activating method and a NH3 activating method separately by taking the biochar as a precursor; the activated microalga-based biochar material obtained through activated modification has micro-mesoporous structures, the large specific surface area and the large pore volume, and the adsorption capacity of porous charcoal is greatly improved.

The invention discloses a magnetic biochar based on iron-enriched plants, and a preparation method and an application thereof. The magnetic biochar based on iron-enriched plants is obtained by directly carrying out high-temperature pyrolysis carbonization or hydrothermal carbonization on the iron-enriched plants. A large amount of iron is accumulated in the iron-enriched plants, and typical iron-enriched plants such as cogongrass are subjected to a high-temperature pyrolysis carbonization or hydrothermal carbonization process to obtain biochar. In the carbonization process, iron enriched in other forms in the plants is converted into magnetic iron oxide, so that the obtained biochar is magnetic biochar, magnetization and carbonization can be synchronously completed without additionally adding a magnetizing agent, no secondary pollution is generated in the preparation process, and the operation is simple. The magnetic biochar can effectively remove heavy metal pollutants in undergroundwater, and has a wide application prospect in the field of underground water heavy metal pollution treatment.

The invention relates to a municipal solid waste reduction, energy regeneration and recycling method, and discloses a domestic waste comprehensive treatment method based on anaerobic digestion and hydrothermal carbonization. The domestic waste comprehensive treatment method comprises the following steps: slurry treatment, anaerobic digestion, hydrothermal carbonization, dewatering and drying. The domestic waste and kitchen waste are subjected to reduction, energy regeneration and recycling treatment, so that the domestic waste comprehensive treatment method is high in resource recycling degree, low in operation cost, clean and environment-friendly, and can ensure that pathogenic microorganisms in the wastes are completely killed, so that repugnant substances are converted and decomposed, and the domestic waste comprehensive treatment method has good economic value and social value.

The present invention relates to a hydro thermal carbonization process for the preparation of coal-like material using biomass. The process comprises a step (i) of heating a reaction mixture comprising water and biomass to obtain a reaction mixture comprising activated biomass; and a step (ii) of adding a polymerization initiator to the reaction mixture obtained in step (i) to polymerize the activated biomass and to obtain a reaction mixture comprising coal-like material. The process is beneficial in terms of product control, and process engineering.

A preparation method of nano-sized silicon and a silicon / carbon composite material is disclosed. A nano-sized silicon-containing by-product produced during the process of industrial smelting of metal silicon, silicon-iron alloy and the like is reduced directly by a metallothermic reduction process, so as to obtain a nano-sized silicon material; the nano-sized silicon material undergoes ball-milling along with a carbon material and / or is mixed with a carbon precursor; and through hydrothermal carbonization and solvent thermal treatment, pyrolysis carbonization, or chemical vapor deposition of carbon, the nano-sized silicon / carbon composite material is prepared. The nano-sized silicon and / or composite material can be used as an active negative material or used in an energy storage system. According to the preparation method, processes with disadvantages of tedious technology, complex equipment and energy consumption, such as removal of impurities in advance, nano-structuring and the like, are not required; raw material resources are rich, cheap and easily available; technology is simple; costs are low; and the method is easy for amplification.

The invention relates to a method for preparing a high-specific surface area porous carbon material based on oil tea seed husks and an application thereof. The preparation method of the carbon material comprises the following steps: performing hydrothermal carbonization on the oil tea seed husk powder to obtain a black solid, using water and ethanol for cleaning the black solid and drying the black solid, adding KOH and grinding and performing hole expanding, then placing a mixing sample in inert gas flow atmosphere, separately using dilute hydrochloric acid and water for washing an obtained grey solid until the grey solid is neutral, performing pumping filtration, and naturally drying the product in air to obtain the high-specific surface area porous carbon material. The carbon material has excellent adsorption performance on heavy metal, a dye and perfluorinated sulfonic acid pollutants in water. The method has the advantages that the raw material is biomass waste, the source is wide, the cost is low; processes for preparing the carbon material is simple, the used reagents are conventional chemical reagents, the production cost is low; and the adsorptivity of the carbon material on a plurality of pollutants in water is better than that of the reported materials.

The invention discloses a preparation method of a sludge-based charcoal slow-release phosphate fertilizer, which comprises: adding a conditioner into sludge, and uniformly stirring to obtain conditioned sludge; placing the conditioned sludge into a hydrothermal reactor, sealing, and heating to perform a hydrothermal carbonization reaction so as to obtain hydrothermal carbonated solution; carrying out solid-liquid separation on the hydrothermal carbonated solution, washing a solid product, and drying at a temperature of 40 to 60 DEG C to obtain sludge-based charcoal; placing the sludge-based charcoal into phosphate solution, after oscillating for 16 to 48h at a speed of 100 to 200r / min, carrying out solid-liquid separation, and drying a solid product at a temperature of 40 to 60 DEG C to obtain the sludge-based charcoal slow-release phosphate fertilizer. The invention further discloses a sludge-based charcoal slow-release phosphate fertilizer. The preparation method of the sludge-based charcoal slow-release phosphate fertilizer, which is disclosed by the invention, is low in cost, high in processing efficiency and high in solid yield; the charcoal slow-release phosphate fertilizer disclosed by the invention is slowly released, effectively prevents pollution of the fertilizer to the environment, and can improve solid and prevent soil hardening.

The invention discloses a carbon-based solid acid catalyst synthesized by one-step hydrothermal carbonization process, belonging to the technical field of chemical synthesis. In the invention, carbonizable compounds and sulfo-containing functional molecules are prepared into aqueous solution, placed in an autoclave, heated at 150-200 DEG C for 4-10 hours in a baking oven, cooled to room temperature, filtered after opening the autoclave, washed and dried to obtain a novel carbon-based solid acid catalyst. The solid acid has the following advantages: the synthesis process is simple and convenient, which can be finished in one step; synthesis cost is low; catalytic effect is good, and the solid acid catalyst has higher catalytic activity to general acid catalyzed reactions such as esterification, condensation, alkylation, etherification, ester exchange and the like; and the catalyst can be used repeatedly.

The invention discloses a method for preparing biological carbon from tobacco stems. The method for preparing the biological carbon from the tobacco stems comprises the following steps: (1), crushing the tobacco stems, and then enabling the crushed tobacco stems and water to be subjected to a hydrothermal carbonization reaction at 180-260 DEG C; after terminating the reaction, filtering, washing and drying an obtained product in sequence; (2), activating the product, which is dried in Step (1), by an activating agent, afterwards, calcining the activated product at 400-1200 DEG C in an inert atmosphere, and subsequently, washing the calcined product with water, drying the water-washed product, and obtaining the biological carbon. The activating agent is at least one of a lewis acid, a peroxide, an alkali metal hydroxide and an alkali metal carbonate. The invention also discloses the biological carbon prepared by adopting the method and application of the biological carbon to the adsorption of heavy metal. An obtained biological carbon material has advantages of relatively small particle sizes, relatively large specific surface area, relatively strong adsorption capacity and the like, and can be applied to the adsorption and the repair of heavy metal ions in a water body and a soil environment.

The invention relates to a method for preparing nitrogen self-doped three-dimensional graphene from peels. With peels as a carbon source and a nitrogen source, the method comprises the following steps: performing hydrothermal carbonization; performing activation treatment using an activator; and performing acid washing and drying to obtain the nitrogen self-doped three-dimensional graphene. In the invention, since the peels are selected as a raw material for preparing the nitrogen self-doped three-dimensional graphene, the needs for sustainable development and environmental protection can be met, and the raw material cost is effectively reduced. The specific surface area of the prepared product exceeds 1700m<2>g<-1>; the relatively large specific surface area and three-dimensional graphene porous structure are beneficial to the transfer and transport of ions in the electrolyte; and the electrical conductivity is very good. Due to the doping of nitrogen element, active sites for catalysis and lithium storage reactions can be formed, and the nitrogen self-doped three-dimensional graphene can be widely applied to the fields of energy storage and transformation such as fuel cells and lithium ion batteries. Moreover, the graphene material has excellent electrical conductivity, and the carbon material has relatively high activity due to the doping of nitrogen element.

The invention discloses a method for preparing carbon microspheres through hydrothermal carbonization of a biomass. The method comprises the following steps: stirring and mixing camellia seed husk powder which serves as a raw material and deionized water, treating the mixture ultrasonically, transferring the treated mixture into a stainless steel reactor, introducing an inert gas into the stainless steel reactor to remove oxygen, putting the stainless steel reactor into an air blowing drying box, carrying out reaction at a constant temperature, cooling the product of reaction to room temperature, pouring out the upper-layer liquid, tanking out the solid, clearing the solid ultrasonically with deionized water and ethanol in sequence until the washing liquid is colorless, extracting with ultrasonic waves and microwaves in the solution of ethanol in water, filtering the mixture in vacuum, and drying in a vacuum drying box to obtain the carbon microspheres. The method disclosed by the invention has the advantages that the raw material for preparing the carbon microspheres is a biomass waste which is wide in source and low in cost, the process of preparing the carbon microspheres is simple and is friendly to environment, no poisonous and harmful reagents are adopted in the whole preparation process, and the prepared poisonous carbon microspheres are uniform in size and can be used conveniently. In addition, the method is low in production cost and can realize large-scale production.

The invention relates to a nitrogen doped carbon material and a preparation method, and relates to the carbon material and the preparation method. The nitrogen doped carbon material is prepared by a nitrogen source and a carbon source through employing a hydrothermal method with one step synthesis, the preparation method comprises the following steps: weighting the nitrogen source in a three-neck flask, adding distilled water, heating and stirring to dissolve the nitrogen source, weighting the carbon source, adding distilled water for shaking and then moving to the three-neck flask, continuously stirring, performing polymerization on a reaction system at a constant temperature, moving a performed polymer system to a gallipot in polytetrafluoroethylene in a reaction vessel, performing centrifugation on the obtained product after hydrothermal carbonization, placing the separated sediment in a baking oven, and cooling to the room temperature to obtain the nitrogen doped carbon material. The carbon material is prepared by a hydrothermal method with one step synthesis, the reaction condition is wild, the step is simple, the equipment requirement is low, the production cost is reduced, and the nitrogen content of the prepared nitrogen doped carbon material is high, the nitrogen doped carbon material has large surface area, and provides guarantee for good applicability.

The invention discloses a method for preparing biological activated carbon by hydrothermal carbonization of algae residue / algae sludge.The method includes the following steps: (1) mixing the algae residue / algae sludge with water prior to putting the mixture into a reaction kettle, performing heating reaction under the pressure less than 6 MPa and at the temperature of 160-220 DEG C for 2-20 hours, and naturally cooling to the room temperature; (2) subjecting a hydrothermal product obtained in the step (1) to filtration or centrifugal separation to obtain solid, and washing the solid; (3) drying the product obtained after washing in the step (2) at the temperature of 50-60 DEG C to obtain the biological activated carbon.Plenty of algae residue can be disposed highly efficiently as well as be utilized to turn waste into treasure; harm brought by the algae residue and algae toxins is reduced, and high efficiency and environmental friendliness are realized.

The invention discloses a preparation method of biomass active carbon with high mesoporous rate and active carbon obtained thereby. The preparation method comprises the steps of: raw-material crushing, hydrothermal carbonization of acid, low-temperature activation, high-temperature activation and washing with water and the like, and phosphoric acids are adopted as activating agents to prepare biomass into active carbon. Compared with the prior art, the preparation method disclosed by the invention has the following advantages that the hydrothermal carbonization and one-time air activation areadopted to promote hydrolysis and dehydration reaction of the phosphoric acids for polysaccharides such as cellulose and hemicellulose and the like in biomass, so that the condensation reaction amongthe phosphoric acids is reduced and the activating effect of the phosphoric acids is promoted; the production process is simple, and the equipment requirement is low; no other catalysts need to be added, so that the production cost is reduced; the phosphoric acids for activation can be recovered after washing, so that no pollution is caused; the prepared active carbon has larger specific surface area and developed pore structure, wherein the total pore volume is 2.0447cm<3>.g<-1>, the mesoporous pore volume is 1.976cm<3>.g<-1>, the mesoporous rate is 95% or more, the effect for removing methylene blue is better and the market application prospect is great.

The invention relates to a process for preparing high-purity hydroxyapatite (HA) from eggshells under a hydrothermal condition. The structural feature of the synthesized HA powder is similar to that of the natural skeleton HA; and the synthesized HA comprises OH<->, H2O, CO3<2-> and other groups. A single HA particle is in nano size, and the HA particles aggregate into micron large granules. The existing preparation methods for HA comprise a chemical precipitation method, a hydrothermal synthesis method, a sol-gel method, a micro-emulsion method and the like; the raw materials for preparation mainly comprise chemical materials, animal skeletons, coral and the like, and have the defects of high price, high preparation cost and the like; and at present, about 400 thousand tons of eggshells are discarded in China every year, thereby causing serious environmental pollution and waste of resources. According to the invention, abundant calcium in the eggshells is utilized, and a proper preparation method is used for synthesizing the HA, thereby lowering the production cost of the HA and effectively increasing the added value of an eggshell utilization technique.

The invention provides a method for recycling a surplus sludge hydrothermal carbonization solution, which belongs to the technical field of environment engineering sludge treatment. The hydrothermal carbonization solution is appropriately circularly utilized in the hydrothermal carbonization process of the surplus sludge, so that while the yield of hydrothermal carbon is increased, the high-concentration hydrothermal carbonization solution which is easy to recycle is generated, nitrogen and phosphorus in the high-concentration hydrothermal carbonization solution are recycled through a struvitemethod, and a liquid phase part is used as a denitrification supplementary carbon source in the sewage biological denitrification. The method has the beneficial effects that the zero emission of thesurplus sludge in the sewage treatment can be realized, the technical bottleneck that the low-carbon-nitrogen-ratio waste water biological denitrification efficiency is low can be effectively overcome; and moreover, the hydrothermal carbon can be used as fuel for heating a hydrothermal carbonization reactor, so that the energy self-supply can be realized, and the application prospect in the aspectof recycling the surplus sludge in an urban sewage treatment factory is wide.

The invention relates to a method for preparing granular active carbon by using biomass, wherein the granular active carbon is prepared by using biomass as a raw material through hydrothermal carbonization, molding and activation, the biomass comprises corn straw, wheat straw, soybean straw, cotton straw, tobacco straw, rice straw, sawdust, Salix psammophila, water hyacinth or pine branch biomass,and the activator can be zinc chloride, sulfuric acid, phosphoric acid, potassium carbonate, potassium hydroxide and ferric chloride. According to the present invention, corn straw and sawdust are used as the raw materials, and can generate the hydrothermal carbon with strong bonding effect and the hydrothermal liquid with high added value through hydrothermal carbonization, the hydrothermal carbon has a certain bonding effect, and the specific surface area and the pore volume of large-particle active carbon are increased with zinc chloride and ferric chloride, such that the granular active carbon integrating good compressive strength and high adsorption performance is obtained so as to improve the application value.

The invention discloses a preparation method of a lignin-based hydrothermal-carbon sulfonic acid catalyst. The hydrothermal-carbon sulfonic acid catalyst is prepared from alkali lignin, which serves as a raw material, in industrial papermaking waste liquid through refining, hydrothermal carbonization and sulfonation; the solid acid is abundant in oxygen containing functional groups and has relatively good hydrophilicity and thermal stability, and the yield of reducing sugar, which is obtained through carrying out catalyzed hydrolysis on cellulose by the solid acid, can reach 50% to 75%. After reactions end, the catalyst is easy to separate and can be reused. The solid acid catalyst obtained by the method is simple in preparation process, is environmentally friendly and has relatively high catalytic activity, so that a new way for realizing the resource-converting utilization of biomass is developed.

The invention provides a preparation method of a carbon material for adsorbing hydrophilic ionic liquid. The method comprises the following steps: performing hydrothermal reaction on cellulose which serves as a raw material in a high-pressure hydrothermal reaction kettle to obtain carbon microspheres rich in oxygen-containing groups such as hydroxyl and carboxyl; and activating the carbon microspheres in a muffle furnace by using KOH under the protection of nitrogen atmosphere to obtain a spongy carbon material with the large specific surface area and the surface rich in the oxygen-containing groups. The carbon microspheres with the surface rich in the oxygen-containing groups can be obtained by incomplete hydrothermal carbonization of the cellulose, the specific surface area of the carbon material can be greatly improved by KOH activation under the condition of retaining oxygen-containing chemical groups on the surface, a pore channel structure is improved, a carbon material adsorbent with unique hydrophilic ionic liquid adsorption performance is finally obtained, and the adsorption efficiency and the adsorption capacity are greatly improved. The needed raw materials are common and easily available, the preparation method is simple, and the obtained carbon material adsorbent has good effects on adsorption and recycling of the hydrophilic ionic liquid in wastewater.

The present invention is to tackle the volume expansion problem of the Si anode materials in the application of lithium ion batteries. In the present invention, a simple and green hydrothermal method is use to form loosely packed Si@C core / shell structure. A carbon coating layer is formed on controllably aggregated silicon nanoparticles in a one-step procedure by the hydrothermal carbonization of a carbon-rich precursor.

The invention relates to the field of treatment to heavy metal pollution in water and soil, in particular to a preparation method of multi-site activated and modified reed-lutarioriparius biochar andapplication thereof to removal of heavy metals zinc and cadmium. The preparation method comprises the following steps: firstly washing, drying and crushing reed-lutarioriparius biomass, ultrasonicallystirring in an aqueous manganese ore powder solution thoroughly, then performing low-temperature hydrothermal carbonization to produce unactivated and unmodified biochar, then soaking the biochar ina calcium chloride-hydrogen peroxide mixed solution, activating a biochar-calcium chloride-hydrogen peroxide mixed solution by using microwave, and then modifying the dried biochar through ultravioletradiation to obtain activated and modified biochar, wherein the obtained biochar is applied to the removal of the heavy metals zinc and cadmium in the water and the soil. An application method comprises the following steps: adding the activated and modified biochar into heavy metal zinc and cadmium wastewater for an adsorption reaction; or directly adding into heavy metal zinc and cadmium contaminated soil, thoroughly mixing uniformly, and aging for a period of time to complete bioremediation of heavy metal zinc and cadmium pollution in the soil.

The invention discloses a low-cost preparing process for one-step synthesis of carbon-coated lithium iron phosphate cathode material with excellent high-rate-performance by in-situ hydrothermal carbonization, and provides a preparation method for solving the defects that the traditional carbon-coated lithium iron phosphate preparing process is complicated, carbon coating is nonuniform and the like. The preparation method of carbon-coated lithium iron phosphate with excellent high-rate-performance comprises the step of: uniformly mixing lithium hydroxide solution, ferrous salt solution, phosphoric acid solution and a carbon source under the protection of inert gas, controlling pH value during reaction process, and after reaction is finished, carrying out solid-liquid separation, drying and high-temperature heat treatment to obtain the high-rate-performance carbon-coated lithium iron phosphate cathode material. According to the invention, lithium iron phosphate has the characteristics of uniform particle size distribution and carbon coating thickness, excellent high-rate-performance, good circulation stability and the like.

The invention relates to the technical field of the resource utilization of livestock and poultry breeding waste, and discloses a continuous hydrothermal carbonization system for livestock and poultryexcrement. The continuous hydrothermal carbonization system comprises a fermentation tank, a high-pressure sludge pump, a heater, a carbonization reactor, a cooler, a storage tank, a sludge pump anda solid-liquid separator, wherein the fermentation tank, the high-pressure sludge pump, the heater, the carbonization reactor, the cooler, the storage tank, the sludge pump and the solid-liquid separator are communicated in sequence; the fermentation tank is also communicated with a first gas collection device through a pipeline; the storage tank is also communicated with a second gas collection device through a pipeline. The invention also discloses a continuous hydrothermal carbonization process for the livestock and poultry excrement. The continuous hydrothermal carbonization process comprises the following steps of fermenting the pretreated livestock and poultry excrement in the anaerobic fermentation tank, then continuously inputting into the heater, the carbonization reactor and cooler through power provided by the high-pressure sludge pump, and separating a temperature-lowered carbonization product through the solid-liquid separator to obtain hydrothermal carbon and carbonized liquid. The system is used for treating the livestock and poultry excrement by adopting a continuous hydrothermal carbonization method to prepare the hydrothermal carbon, meanwhile, is used for obtaining the by-product carbonized liquid, and have the advantages of being convenient to operate, easy to maintain, low in production cost, zero-release in pollutant and low in energy consumption, and thelike.