Method for grading and utilizing by-product of coal liquefaction of coal and heavy oil hydrogenation

Abstract

The application provides a method for grading and quality utilization of coal and heavy oil hydrogenation by-product coal liquefaction products, comprising the following steps: carrying out a first reaction on the coal liquefaction products and an acid-containing aqueous solution, and then carrying out a second solid-liquid separation to obtain a first filtrate and a third solid residue; and carrying out an oxidation reaction on the first filtrate and an oxygen source and an alkali source to obtain a nanoscale iron-based catalyst. The method can treat a large amount of liquefaction residues or heavy products by-produced in the conversion of coal and heavy oil, and obtain a nanoscale iron-based catalyst, super-low-ash pitch and high-concentration and stable-performance coal water slurry meeting the raw material requirements of the coal water slurry, so that the product added value is greatly improved and pollutant emission is reduced.

Description

Technical Field

[0001] This application relates to the field of coal chemical technology, and in particular to a method for the graded and classified utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation. Background Technology

[0002] Direct coal liquefaction, coal tar hydrogenation, and coal-oil co-processing are all technologies that convert coal and heavy oil into clean oil products with low sulfur and low nitrogen.

[0003] Direct coal liquefaction (CDL) is a technology that hydrocracking coal into smaller molecule compounds under high temperature, high pressure, and hydrogen-containing conditions. my country built and put into operation a million-ton-scale CDL demonstration plant in 2008. Coal tar hydrogenation is a widely used technology for the clean processing of coal tar. China already has a million-ton-scale capacity, with suspended bed or slurry bed technologies capable of processing heavy coal tar being one of the processing technologies. Coal-oil co-processing technology is a technology that co-processes and converts coal and heavy oil. my country has built and successfully operated a 450,000-ton / year coal-oil co-processing demonstration plant. Because the raw materials for direct coal liquefaction, coal tar suspension or slurry bed hydrogenation, and coal-oil co-refining technologies contain coal powder, ash, or other solid substances that are difficult to dissolve in solvent oil, and because catalysts are usually added to the reactants to promote the conversion of coal or oil, these catalysts are typically compounds containing one or more metals such as iron, nickel, molybdenum, and cobalt. This results in direct coal liquefaction and coal-oil co-refining producing coal liquefaction residue or coal liquefaction pitch, which accounts for about one-third of the coal input, while coal tar hydrogenation produces heavy residue, which accounts for about 5-20 wt% of the oil. Whether it's the liquefaction residue or heavy residue produced as a byproduct of direct coal liquefaction, coal-oil co-refining, or coal tar hydrogenation, it is a mixture of high-ash and high-sulfur substances that is difficult to process and handle. However, this type of residue also contains some heavy oil, bituminous substances, and unconverted or insufficiently converted coal.

[0004] To address the issue of large-scale utilization of coal liquefaction residues or similar heavy residues, extensive research has been conducted both domestically and internationally on the pyrolysis, combustion, coking, gasification, and extraction of organic matter from these residues. For example, CN103695057A discloses a method for preparing coal-water slurry from direct coal liquefaction residue, the coal-water slurry and its gasification method, CN107892935A discloses a method for generating metallurgical coke by replacing coking coal with direct coal liquefaction residue, and CN109385286A discloses a continuous pyrolysis device and method suitable for direct coal liquefaction residue. However, since most of the organic matter in the residue is heavy oil and asphaltenes, very little light oil can be generated after pyrolysis. The resulting coke is more difficult to process due to its higher ash and sulfur content. Similarly, due to the high viscosity of heavy oil and asphaltenes, it is easy to cause nozzle blockage when used for combustion and gasification. When the residue is used for coking, the high ash and sulfur content seriously affect the quality of the coke. Therefore, such methods are difficult to effectively utilize and process large amounts of liquefaction residue.

[0005] To increase the added value of liquefaction residue, CN105273734A discloses a method for producing carbon black raw materials using coal direct liquefaction residue, CN105802652A discloses a method for preparing modified asphalt from coal liquefaction residue, and CN101962560A and CN104845652A also disclose this method. Patents such as CN103275744A disclose methods for extracting heavy liquefied oil and asphalt from coal liquefaction residues. CN103756703A, CN101580729A, CN106986340A, and CN105720233A further disclose methods for preparing high-value-added carbon material products using coal liquefaction residues. CN101885976A develops a method for extracting heavy liquefied oil and mesophase asphalt-like substances from direct coal liquefaction residues. CN10210741A and CN112029527A disclose a method for recycling the extracted heavy liquefied oil and asphalt together with the raw materials into the liquefaction hydrogenation reaction system. This type of technology is mainly based on separating the organic matter from the residues or using the separated and deashed organic matter to prepare carbon materials or further hydrocracking, thereby further increasing oil production. However, due to the special composition of the residue material, its high ash content and difficulty in separation make it difficult for the deashing system to operate stably for a long period of time, or for the material, heavy oil, and asphaltene to undergo further hydrocracking, thus hindering efficient and high-value utilization. Even if the residue is separated by extraction, about 40% of the high-ash solvent-insoluble matter in the residue is still difficult to utilize effectively and becomes industrial waste, causing not only resource waste but also environmental pollution. Summary of the Invention

[0006] In view of this, the purpose of this application is to solve the problems of existing technologies that cannot process large quantities of coal direct liquefaction residue or cannot efficiently utilize the residue, and to provide a graded and classified utilization method for coal liquefaction products by-products of coal and heavy oil hydrogenation. This method can process large quantities of liquefaction residue or heavy products by-products produced during the coal and heavy oil conversion process, and can improve the added value of each component and reduce pollutant emissions.

[0007] Therefore, this application proposes a method for the graded and graded utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation, including: The coal liquefaction product is reacted with an acidic aqueous solution in the first reaction, followed by a second solid-liquid separation to obtain a first filtrate and a third solid residue. The first filtrate was subjected to an oxidation reaction with an oxygen source and an alkali source to obtain a nano-sized iron-based catalyst.

[0008] In some embodiments, the oxygen source includes at least one of air, oxygen, and hydrogen peroxide.

[0009] In some embodiments, the alkali source includes an alkaline solution or an alkaline gas.

[0010] In some embodiments, the alkaline solution includes at least one of sodium hydroxide solution, calcium hydroxide solution, ammonia, and Lewis base.

[0011] In some embodiments, the alkaline gas is at least one of ammonia or ammonia-containing water vapor.

[0012] In some embodiments, the amount of the alkali source is adjusted to control the pH of the reaction liquid for the oxidation reaction to be 6.5-13.

[0013] In some embodiments, the oxidation reaction is carried out at a temperature of room temperature to 180°C and for a reaction time of 0.1 to 4 hours.

[0014] In some embodiments, the method for graded and differentiated utilization of coal and heavy oil hydrogenation by-products of coal liquefaction further includes a third solid-liquid separation step after the oxidation reaction.

[0015] In some embodiments, the third solid-liquid separation method includes static separation or centrifugal separation, and the centrifugal separation speed is 200-5000 r / min.

[0016] In some embodiments, the acidic aqueous solution comprises an acid solution, or comprises an acid solution and a demulsifier.

[0017] In some embodiments, the acid solution includes at least one of formic acid, acetic acid, hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, and citric acid.

[0018] In some embodiments, the concentration of the acid solution is 1-80 wt%.

[0019] In some embodiments, the demulsifier includes at least one of sodium hexametaphosphate, SP-type demulsifier, AP-type demulsifier, and AE-type demulsifier.

[0020] In some embodiments, the demulsifier in the acidic aqueous solution has a mass content of 0.1-15%.

[0021] In some embodiments, the reaction temperature of the first reaction is room temperature - 300°C.

[0022] In some embodiments, the method for graded and differentiated utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation further includes a step of pretreating the coal liquefaction products before the first reaction; the pretreatment method includes: The coal liquefaction product is dissolved in a first composite solvent under a first stirring condition, followed by a first solid-liquid separation to obtain a first agent-oil mixed solution and a first solid residue. The first solid residue is subjected to a first drying process to obtain a second agent-oil mixture solution and a second solid residue. The first and second agent oil mixtures are mixed and then subjected to a first distillation to obtain the recovered first composite solvent, heavy oil, and light asphalt.

[0023] In some embodiments, the coal liquefaction products include at least one of direct coal liquefaction residue, coal liquefaction pitch, coal-oil co-processing residue, and coal tar hydrogenation residue.

[0024] In some embodiments, the first composite solvent includes at least one of coal-based light oil, benzene, toluene, xylene, petroleum ether, and tetrahydrofuran.

[0025] In some embodiments, the mass ratio of the first composite solvent to the third solid slag is (1-20):1.

[0026] In some embodiments, the first stirring rate is 20-400 r / min, the first stirring temperature is 30-250°C, and the first stirring time is 0.5-3 h.

[0027] In some embodiments, the first solid residue is subjected to a first drying process to obtain a second agent-oil mixture and a second solid residue, comprising: The first solid residue is first dried, and the gas that escapes during the first drying process is first condensed and collected to obtain the second agent oil mixture solution. The first dried solid is dispersed to obtain the second solid residue.

[0028] In some embodiments, the temperature of the first drying is 90-300°C.

[0029] In some embodiments, the temperature of the first condensation is room temperature - 150°C.

[0030] In some embodiments, the first distillation includes a first primary distillation and a first vacuum distillation performed sequentially.

[0031] In some embodiments, the distillation temperature of the material in the first primary distillation column is the initial boiling point -250°C, and the time for the first primary distillation is 0.5-12 hours.

[0032] In some embodiments, the pressure of the first vacuum distillation is 10-1000 Pa, the temperature of the first vacuum distillation is 50-300 °C, and the time of the first vacuum distillation is 0.5-12 h.

[0033] In some embodiments, the method for graded and classified utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation further includes the step of recycling the recovered first composite solvent.

[0034] In some embodiments, the method for graded and differentiated utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation further includes obtaining high-purity asphalt and coal-water slurry products from the third solid residue.

[0035] In some embodiments, obtaining high-purity bitumen and coal-water slurry products from the third solid slag includes: The third solid residue is dissolved in the second composite solvent, followed by a fourth solid-liquid separation to obtain a third oil-liquid mixture and a fourth solid residue. The fourth solid residue is subjected to a second drying process to obtain a fourth agent-oil mixture solution and a fifth solid residue. The third and fourth oil mixtures are subjected to a second distillation to obtain the recovered second composite solvent and heavy asphaltene. The heavy oil, the light asphalt, and the heavy asphalt are first mixed to obtain the high-purity asphalt; The fifth solid slag, coal powder, and coal-water slurry additives are mixed in a second process to obtain the coal-water slurry product.

[0036] In some embodiments, the high-purity asphalt refers to asphalt with an ash content of less than 50 ppm.

[0037] In some embodiments, the second composite solvent includes at least one of coal-based wash oil, decrystalline anthracene oil, coal liquefaction middle distillate, tetrahydrofuran, quinoline, N,N-dimethylformamide, and N,N-dimethylpyrrolidone.

[0038] In some embodiments, the fourth solid-liquid separation is performed using either a filter screen or centrifugation.

[0039] In some embodiments, the fourth solid-liquid separation is performed using a filter screen, and the pressure during the filter screen filtration is 0.2-5 MPa, and the temperature is 150-350°C.

[0040] In some embodiments, the temperature of the second drying is 200-350°C.

[0041] In some embodiments, the fourth solid residue is subjected to a second drying to obtain a fourth oil-based mixture and a fifth solid residue, comprising: The fourth solid residue is subjected to a second drying process, and the gas that escapes during the second drying process is collected after a second condensation to obtain a fourth agent oil mixed solution. The fifth solid residue is obtained by dispersing the second dried solid.

[0042] In some embodiments, the second distillation includes a second primary distillation and a second vacuum distillation performed sequentially.

[0043] In some embodiments, the distillation temperature of the material in the second primary distillation column is the initial boiling point -150°C, and the time for the second primary distillation is 0.5-12 hours.

[0044] In some embodiments, the pressure of the second vacuum distillation is 10-1000 Pa, the temperature of the second vacuum distillation is 50-350 °C, and the time of the second vacuum distillation is 0.5-12 h.

[0045] In some embodiments, the temperature of the second condensation is room temperature - 150°C.

[0046] In some embodiments, the ash content of the heavy asphalt is 1-150 ppm.

[0047] In some embodiments, the coal powder includes coal powder of different particle size grades.

[0048] In some embodiments, the mass ratio of the fifth solid slag, the pulverized coal, and the coal-water slurry additive is (1-2):(2-8):(0.001-0.04).

[0049] In some embodiments, the concentration of the fifth solid slag is 20-50 wt%.

[0050] In some embodiments, the method for graded and classified utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation further includes the step of selling the heavy oil as a solvent oil or a product, and / or the step of using at least one of the heavy oil, light asphaltene, and heavy asphaltene in the production of high-end carbon materials or selling it as a product.

[0051] The method for graded and differentiated utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation in this application can bring at least the following beneficial effects: 1. For the first time, the active metals in iron-based catalysts used in coal and heavy oil hydrogenation processes have been recovered, and the recovered active metals have been prepared into nanoscale catalysts.

[0052] 2. Multi-stage separation of coal liquefaction products not only enables the comprehensive utilization of this type of asphalt, but also allows for the high-value utilization of each component of the asphalt.

[0053] 3. It fully avoids the operational difficulties caused by the characteristics of each component in this type of asphalt to the separation process, such as high content of heavy oil, small particles of metal substances that easily clog the filter screen and are easily mixed with asphalt, and high viscosity of asphalt that easily adheres to inorganic minerals, resulting in high impurity content in heavy asphalt.

[0054] 4. It can maximize the recovery of heavy pitch from coal tar pitch, a byproduct of coal and heavy oil hydrogenation, and the resulting pitch has high aromatic carbon content, extremely low impurity content, controllable quality, and wide range of applications.

[0055] 5. The organic solvents used, such as the first composite solvent and the second composite solvent, are all reliable in origin, low in cost, stable and controllable in properties, and have low recycling costs, thus exhibiting good economic efficiency.

[0056] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0057] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings. in: Figure 1 This is a flowchart illustrating a method for the graded and graded utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation, as an exemplary embodiment of this application.

[0058] Figure 2 This is a field emission transmission electron microscope (TEM) image of the catalyst recovered in Example 1. Detailed Implementation

[0059] The embodiments of this application are described in detail below, with examples of these embodiments illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0060] In this application, the disclosure of numerical ranges includes all values ​​throughout the range and the disclosure of further subdivisions of the range, including the endpoints and subranges given for these ranges.

[0061] Unless otherwise specified, all raw materials and equipment involved in this application are self-made through commercial means or known methods; and all methods involved are conventional methods unless otherwise specified.

[0062] In this application, room temperature refers to 20-30°C.

[0063] The method for graded and differentiated utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation in this application involves directly or indirectly recovering nanoscale iron-based catalysts from coal liquefaction products to obtain high-purity asphalt and high-concentration coal-water slurry products.

[0064] The following describes a method for graded and differentiated utilization of coal liquefaction products, a byproduct of coal and heavy oil hydrogenation, according to an embodiment of this application, with reference to the accompanying drawings.

[0065] Figure 1 This is a flowchart illustrating a method for the graded and graded utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation, as an exemplary embodiment of this application.

[0066] like Figure 1 As shown, the method for graded and differentiated utilization of coal and heavy oil hydrogenation by-products of coal liquefaction includes the following steps: 1) The coal liquefaction products are added to the first composite solvent and stirred and dissolved to obtain the first liquid-solid mixture.

[0067] 2) Perform a first solid-liquid separation on the first liquid-solid mixture obtained in step 1) to obtain a first agent oil mixture solution and a first solid residue.

[0068] 3) The first solid residue obtained in step 2) is subjected to a first drying process to recover the first composite solvent, heavy oil and light asphalt that are adsorbed and adhered in the first solid residue. The gas that escapes during the first drying process is collected after the first condensation to obtain a second solvent-oil mixture solution. After the solid is dispersed, a second solid residue is obtained.

[0069] 4) Perform a first distillation on the first agent oil mixture obtained in step 2) and the second agent oil mixture obtained in step 3) to obtain the recovered first composite solvent, heavy oil and light asphalt.

[0070] 5) Add the second solid residue obtained in step 3) into an acidic aqueous solution and stir to disperse it to obtain a second liquid-solid mixture. After the reaction is completed, perform a second solid-liquid separation to obtain the first filtrate and the third solid residue.

[0071] 6) Add an oxygen source and an alkali source to the first filtrate obtained in step 5) to carry out an oxidation reaction.

[0072] 7) The oxidation reaction product obtained in step 6) is subjected to a third solid-liquid separation to obtain the nano-sized iron-based catalyst.

[0073] 8) Add the third solid residue obtained in step 5) into the second composite solvent and stir to dissolve it to obtain the third liquid-solid mixture.

[0074] 9) The third liquid-solid mixture obtained in step 8) is subjected to a fourth solid-liquid separation to obtain a third agent oil mixture solution rich in heavy oil and asphaltenes and a fourth solid residue.

[0075] 10) The fourth solid residue obtained in step 9) is subjected to a second drying to recover the second composite solvent and heavy asphaltene adsorbed and adhered in the fourth solid residue. The gas that escapes during the second drying process is collected after a second condensation to obtain the fourth agent oil mixed solution. After the solid is dispersed, the fifth solid residue is obtained.

[0076] 11) A second distillation of the third agent oil mixture in step 9) and the fourth agent oil mixture in step 10) yields the recovered second composite solvent and heavy asphaltene.

[0077] 12) The heavy oil and light asphalt in step 3) and the heavy asphalt in step 11) are mixed in proportion to obtain high-purity asphalt.

[0078] 13) By mixing the fifth solid slag with coal powder and coal-water slurry additives in the second batch, a high-concentration coal-water slurry product with good stability can be obtained.

[0079] The graded and graded utilization method of coal and heavy oil hydrogenation by-product coal liquefaction products in this application embodiment refers to the solid residues or remnants remaining in the liquefaction or lightening process of coal and heavy oil, including but not limited to at least one of coal liquefaction pitch, direct coal liquefaction residue, coal-oil co-refining residue, and coal tar hydrogenation residue.

[0080] In some embodiments, in step 1), the first composite solvent includes, but is not limited to, at least one of coal-based light oil, benzene, toluene, xylene, petroleum ether, tetrahydrofuran, etc.

[0081] By way of a non-limiting example, coal-based light oil includes, but is not limited to, at least one of coking light oil, coal liquefaction light oil, and coal tar hydrogenated oil.

[0082] In some embodiments, in step 1), the mass ratio of the first composite solvent to the coal liquefaction product is (1-20):1, including but not limited to 1:1, 3:1, 5:1, 8:1, 10:1, 12.5:1, 15:1, 17.5:1, or 20:1. A mass ratio of the first composite solvent to the coal liquefaction product within the above range can improve the dissolution efficiency and separation rate of the raw coal liquefaction product; a ratio lower than 1:1 makes it difficult to effectively separate the insoluble matter of the first composite solvent; a ratio higher than 10:1 results in excessive use of the first composite solvent, increasing recovery volume and energy consumption.

[0083] In some embodiments, in step 1), the first stirring rate is 20-400 r / min, preferably 100-300 r / min; the first stirring temperature is 30-250°C; and the first stirring time is 0.5-3 h.

[0084] In some embodiments, before step 1), the method further includes: crushing the coal liquefaction residue in the coal liquefaction product to less than 3 mm.

[0085] In some embodiments, step 2) includes, but is not limited to, centrifugal separation.

[0086] It should be noted that, in the embodiments of this application, the first oil mixture obtained in step 2) is rich in heavy oil and light asphaltene. In some embodiments, the mass content of heavy oil in the first oil mixture is 1-30%, and the mass content of light asphaltene in the first oil mixture is 1-20%.

[0087] In some embodiments, in step 2), when the first solid-liquid separation is centrifugal separation, the centrifugal speed is 300-10000 r / min, preferably 2000-5000 r / min; the centrifugal separation time is 10-40 min, preferably 20-30 min.

[0088] In some embodiments, step 2) involves subjecting the first solid residue to a first drying process to obtain a second agent-oil mixture and a second solid residue, comprising: The first solid residue is first dried, and the gas that escapes during the first drying process is first condensed and collected to obtain the second oil-mixed solution. The first dried solid was dispersed to obtain the second solid residue.

[0089] As an optional example, in step 3), the first solid residue obtained in step 2) is sent to the first drying tower for drying to recover the first composite solvent, heavy oil and light asphaltene adsorbed and viscous in the first solid residue. The gas that escapes during the first drying process is collected after being condensed to below 150°C by the first condenser to obtain the second solvent oil mixture solution.

[0090] In some embodiments, in step 3), the temperature of the first drying is 90-300°C, preferably 120-250°C.

[0091] In some embodiments, the temperature of the first condensation is room temperature - 150°C.

[0092] In some embodiments, step 4) includes a first primary distillation and a first vacuum distillation performed sequentially.

[0093] In some embodiments, the distillation temperature of the first primary distillation column feed is from the initial boiling point to 250°C. It should be noted that the "initial boiling point" in the distillation temperature of the first primary distillation column feed refers to the temperature at which the first composite solvent begins to distill.

[0094] In some embodiments, the time for the first initial distillation is 0.5-12 hours, including but not limited to 0.5 hours, 2 hours, 4 hours, 8 hours, 10 hours, or 12 hours.

[0095] In some embodiments, the pressure of the first vacuum distillation is 10-1000 Pa, including but not limited to 10 Pa, 100 Pa, 250 Pa, 500 Pa, 750 Pa or 1000 Pa.

[0096] In some embodiments, the temperature of the first vacuum distillation is 50-300°C, including but not limited to 50°C, 100°C, 150°C, 200°C, 250°C, or 300°C.

[0097] In some embodiments, the time for the first vacuum distillation is 0.5-12 hours, including but not limited to 0.5 hours, 2 hours, 4 hours, 8 hours, 10 hours, or 12 hours.

[0098] As an optional example, in step 4), the first solvent oil mixture obtained in step 2) and the second solvent oil mixture obtained in step 3) are respectively sent to storage tanks for solvent recovery, and then pumped into a distillation column for the first primary distillation. The distillation temperature of the material in the first primary distillation column is controlled at the initial boiling point -250°C. Then, a first vacuum distillation is carried out under reduced pressure to further separate the heavy oil and asphaltene. The heavy oil and asphaltene are respectively sent to product storage tanks. Part of the heavy oil is sold as solvent oil or product, and at least one of the heavy oil and light asphaltene is used as one of the raw materials for the production of high-end carbon materials or sold as a product.

[0099] In some embodiments, the recovered first composite solvent obtained in step 4) is returned to step 1) for dissolving coal liquefaction products such as residues.

[0100] In some embodiments, in step 5), the acid-containing aqueous solution includes an acid solution.

[0101] In some other embodiments, in step 5), the acidic aqueous solution includes an acid solution and a demulsifier.

[0102] By way of non-limiting example, acid solutions include, but are not limited to, solutions of one or more of the following organic and inorganic acids: formic acid, acetic acid, hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, citric acid, etc.

[0103] In some embodiments, the mass concentration of the added acid solution is 1-80 wt%, preferably between 5-50%.

[0104] By way of non-limiting example, demulsifiers include, but are not limited to, sodium hexametaphosphate, SP type demulsifier with polyoxyethylene polyoxypropylene octadecyl alcohol ether as the main component, AP type demulsifier with polyoxyethylene polyoxypropylene polyether as the main component with polyethylene polyamine as the initiator, AE type demulsifier with polyoxyethylene polyoxypropylene polyether as the main component with polyethylene polyamine as the initiator, and a mixture of several of these.

[0105] In some embodiments, the demulsifier has a mass content of 0.1-15% in an acidic aqueous solution, more preferably 1-8%.

[0106] As an alternative example, in step 5), the obtained second solid residue is dispersed and then added to an acidic solution containing a demulsifier.

[0107] In some embodiments, in step 5), the rate of addition of the acidic aqueous solution is controlled by the temperature inside the reactor (the temperature of the reaction in step 5).

[0108] In some embodiments, in step 5), the reaction temperature for the reaction between the second solid residue and the acidic aqueous solution is room temperature to 300°C, preferably between room temperature and 200°C, such as 30°C, 50°C, 70°C, 100°C, 150°C, or 200°C.

[0109] In some embodiments, in step 5), the second solid-liquid separation method includes pressure filtration separation, centrifugal separation, etc., with pressure filtration separation being preferred.

[0110] In some embodiments, in step 5), the mass content of the second solid residue in the second liquid-solid mixture is 5-50%, including but not limited to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%. That is, in step 5), the mass ratio of the second solid residue to the acid-containing aqueous solution is (1-10):(1-20).

[0111] In some embodiments, in step 6), the oxygen source includes, but is not limited to, at least one of air, oxygen, hydrogen peroxide, etc.

[0112] As an alternative example, when hydrogen peroxide is used as the oxygen source, the mass concentration of hydrogen peroxide is 5-30 wt%.

[0113] In some embodiments, in step 6), the amount of oxygen source used is based on exceeding the amount required for the reaction during metal oxidation.

[0114] As an optional example, in step 6), the oxygen source is oxygen, and the amount of oxygen introduced is controlled to be 1-15 times the amount of active metal (iron).

[0115] In some embodiments, in step 6), the alkali source includes, but is not limited to, alkali solution or alkali gas.

[0116] Among them, the alkaline solution contains OH- - An alkaline solution.

[0117] By way of non-limiting example, alkaline solutions include, but are not limited to, sodium hydroxide solution, calcium hydroxide solution, ammonia water or ammonia gas, and other solutions that can ionize into OH- in aqueous solution. - A mixture of one or more Lewis bases of the ion.

[0118] In some embodiments, OH in alkaline solutions - The concentration is 0.1-5 mol / L.

[0119] By way of non-limiting example, alkaline gases include, but are not limited to, at least one of ammonia or ammonia-containing water vapor.

[0120] It should be noted that the higher the volume content of ammonia in the ammonia-containing steam, the better.

[0121] In some embodiments, in step 6), the amount of alkali source used is determined by controlling the pH of the reaction liquid of the oxidation reaction to be 6.5-13.

[0122] As an optional example, in step 6), the amount of alkali source used is adjusted to control the pH of the reaction liquid for the oxidation reaction to be 7-9.

[0123] In some embodiments, in step 6), the rate at which the alkali source is added is determined by controlling the temperature of the oxidation reaction in the reactor to the target reaction temperature and the time of the oxidation reaction to the target reaction time.

[0124] In some embodiments, in step 6), the reaction temperature of the oxidation reaction is between room temperature and 180°C, preferably between room temperature and 100°C, such as 10°C, 25°C, 50°C, 75°C, or 100°C.

[0125] In some embodiments, in step 6), the reaction time of the oxidation reaction is 0.1-4h, preferably 0.2h-2h, for example, 10℃, 25℃, 50℃, 75℃ or 100℃.

[0126] In some embodiments, in step 6), the oxidation reaction is carried out in a bubble reactor, and the first filtrate is added first, followed by the simultaneous addition of an oxygen source and an alkali source.

[0127] In some embodiments, in step 7), the third solid-liquid separation method includes, but is not limited to, static separation or centrifugal separation.

[0128] As an optional example, in step 7), when the third solid-liquid separation method is centrifugal separation, low-speed centrifugal separation is used, with a centrifugal separation speed of 500-5000 r / min.

[0129] It should be noted that in step 7), the purpose of the third solid-liquid separation of the oxidation reaction obtained in step 6) is to remove excess water and obtain a nano-sized iron-based catalyst. As a non-limiting example, the water content in the nano-sized iron-based catalyst is 5-60 wt%.

[0130] In some embodiments, in step 8), the second composite solvent includes, but is not limited to, at least one of the following solvents: coal-based wash oil distillate, decrystalline anthracene oil, coal liquefaction middle distillate, tetrahydrofuran, quinoline, N,N-dimethylformamide, and N,N-dimethylpyrrolidone.

[0131] In some embodiments, in step 8), the mass ratio of the second composite solvent to the third solid slag is (1-10):1, including but not limited to 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1, etc.

[0132] In some embodiments, in step 9), the fourth solid-liquid separation employs either filter filtration or centrifugal separation.

[0133] As an optional example, in step 9), the fourth solid-liquid separation uses a filter screen, and more preferably, the filter screen is pressure filtration, such as plate and frame filter press.

[0134] In some embodiments, in step 9), the pressure when the fourth solid-liquid separation is performed using a filter screen is 0.2-5 MPa, preferably 0.8-3 MPa.

[0135] In some embodiments, in step 9), the filtration temperature when the fourth solid-liquid separation is performed using a filter screen is 150-350°C, preferably between 200-300°C.

[0136] In some embodiments, in step 10), the temperature of the second drying is 200-350°C, preferably 200-300°C.

[0137] In some embodiments, in step 10), the temperature of the second condensation is below 150°C, preferably room temperature - 150°C.

[0138] As an optional example, in step 10), the fourth solid residue obtained in step 9) is sent to the second drying tower for drying to recover the second composite solvent and heavy asphaltene adsorbed and adhered in the fourth solid residue. The gas that escapes during the second drying process is collected after being condensed to below 150°C by the third condenser to obtain the fourth agent oil mixture solution.

[0139] In some embodiments, step 11) includes a second primary distillation and a second vacuum distillation performed sequentially.

[0140] In some embodiments, in step 11), the distillation temperature of the material from the second primary distillation column is the initial boiling point -150°C. It should be noted that the "initial boiling point" in the distillation temperature of the material from the second primary distillation column refers to the temperature at which the second composite solvent begins to dissolve.

[0141] In some embodiments, in step 11), the time for the second initial distillation is 0.5-12 hours, including but not limited to 0.5 hours, 2 hours, 4 hours, 8 hours, 10 hours, or 12 hours.

[0142] In some embodiments, in step 11), the pressure of the second vacuum distillation is 10-1000 Pa, including but not limited to 10 Pa, 100 Pa, 250 Pa, 500 Pa, 750 Pa or 1000 Pa.

[0143] In some embodiments, in step 11), the temperature of the second vacuum distillation is 50-350°C, including but not limited to 50°C, 100°C, 150°C, 200°C, 250°C, or 300°C.

[0144] In some embodiments, in step 11), the second vacuum distillation time is 0.5-12h, including but not limited to 0.5h, 2h, 4h, 8h, 10h or 12h.

[0145] As an optional example, in step 11), the third agent oil mixture obtained in step 9) and the fourth agent oil mixture obtained in step 10) are respectively sent to the storage tank of the solvent recovery unit, and then pumped into the distillation tower for the second primary distillation. The distillation temperature of the material in the second primary distillation tower is controlled at the initial boiling point -150°C. Then, the second vacuum distillation is carried out under reduced pressure to obtain the recovered second composite solvent and heavy asphaltene.

[0146] In some embodiments, in step 11), heavy bitumen can be used as one of the raw materials for producing high-end carbon materials or sold directly as a product.

[0147] In some embodiments, in step 11), the ash content of heavy asphalt is controlled to be 1-150 ppm, preferably 5-50 ppm.

[0148] In some embodiments, in step 12), the mass ratio of the three components—heavy oil, light asphalt, and heavy asphalt—in the first mixing is (0.5-5):(1-15):(0.1-5), including but not limited to 0.5:1:0.1, 0.5:15:5, 0.5:1:5, 0.5:15:0.1, 5:15:5, or 3:8:2.5, etc.

[0149] In some embodiments, in step 12), high-purity asphalt refers to ultra-low ash asphalt with an ash content of less than 50 ppm.

[0150] As a non-limiting example, in step 12), the ash content in the high-purity asphalt includes, but is not limited to, 5ppm, 10ppm, 15ppm, 20ppm, 25ppm, 30ppm, 35ppm, 40ppm, or 45ppm.

[0151] In some embodiments, in step 13), the coal powder includes coal powder of different particle size grades.

[0152] As an optional example, in step 13), the coal powder includes: 0.5-5 wt% of coal powder with a particle size >0.425 mm, 20-35 wt% of coal powder with a particle size of 0.15-0.425 mm, and 15-30 wt% of coal powder with a particle size of 0.075-0.15 mm.

[0153] In some embodiments, in step 13), the mass ratio of the fifth solid slag, pulverized coal, and coal-water slurry additive is (1-2):(2-8):(0.001-0.04), including but not limited to 1:2:0.001, 1:2:0.04, 1:8:0.001, 1:8:0.04, 2:8:0.04, 2:2:0.001, 2:2:0.04, 2:8:0.001, or 1:5:0.02, etc.

[0154] In the embodiments of this application, the coal-water slurry additive used in step 13) is not specifically limited, and any commercially available coal-water slurry additive in the art can be used. As a non-limiting example, the coal-water slurry additive in step 13) includes, but is not limited to, sodium naphthalene sulfonate or a substance containing sodium naphthalene sulfonate, sodium lignosulfonate or a substance containing sodium lignosulfonate, polyacrylamide flocculant or a substance containing polyacrylamide, and at least one of hydroxymethyl cellulose and a substance containing hydroxymethyl cellulose.

[0155] In some embodiments, in step 13), the fifth solid residue is mixed with coal powder of different particle sizes and coal-water slurry additives to prepare a slurry, which can obtain a coal-water slurry product with good stability, high calorific value and high concentration. The concentration of the fifth solid residue (explanation: the fifth solid residue is a water-insoluble powder solid composed of organic and inorganic matter, which can replace the fine coal powder in the coal-water slurry, thereby reducing the amount of coal powder prepared for the coal-water slurry raw material, and thus reducing the amount of raw material prepared and reducing energy consumption) is controlled to be between 15-50 wt%, preferably between 20-40 wt%.

[0156] The method for graded and differentiated utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation in this application embodiment can recover and utilize some of the metals in the inorganic matter of coal liquefaction products as nanoscale iron-based catalysts, achieving efficient utilization of the active component iron in the residue. Simultaneously, after removing some of the active component metallic iron, it is more conducive to reducing the ash content in asphalt and effectively separating asphalt-like substances. Furthermore, the final residue after removing some of the active component metallic iron has a relatively increased organic matter content and smaller particle size, making it suitable for direct use in preparing high-concentration and stable coal-water slurry. Therefore, it can replace the minimum particle size of coal powder required for coal-water slurry preparation, reducing the amount of coal powder used and grinding, thereby reducing the energy consumption of coal powder preparation and achieving the goal of resource utilization of high-ash and high-sulfur coal liquefaction byproduct asphalt.

[0157] The following non-limiting embodiments further illustrate certain features of the present technology.

[0158] Example 1 This embodiment provides a method for graded and quality-based utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation. It uses coal liquefaction pitch byproducts from a domestic demonstration direct liquefaction plant, and its basic properties are shown in Table 1 below.

[0159] Table 1. Properties of Coal Liquefaction Bituminous Pitch By-product from a Million-Ton Coal Direct Liquefaction Unit

[0160] The graded and graded utilization method for coal liquefaction products byproducts of coal and heavy oil hydrogenation is as follows: 100 kg of coal direct liquefaction by-product pitch, crushed to less than 3 mm, was added to 450 kg of a first composite solvent. The first composite solvent was a mixture of coking light oil, coal-based light oil, xylene, and petroleum ether, with a mass ratio of coking light oil: coal-based light oil: xylene: petroleum ether of 1:1:1:1. The coal-based light oil was coal liquefaction light oil. The liquid-solid mixture was stirred at 60°C and 200 r / min for 1 hour. Then, the homogenized liquid-solid mixture was pumped into a centrifuge at 4000 r / min for separation. The residence time of the material in the centrifuge was approximately 15 minutes, yielding a first oil-based mixed solution and a first solid residue. The first solid residue from centrifugation is sent to a dryer for drying to recover the first composite solvent and other liquids adsorbed and adhered to it, yielding a second solid residue. The escaped gas is condensed to below 50°C in a condenser (condensing medium temperature between 30~120°C, e.g., 40°C) and then sent to a distillation system along with the centrifuged liquid (i.e., the first solvent oil mixture). Distillation separates the first composite solvent, heavy oil, and light asphaltene. Specifically, distillation is performed using a combination of atmospheric and vacuum distillation. Atmospheric distillation begins at a distillation temperature of 120°C and slowly reduces the pressure for approximately 3.5 hours. Vacuum distillation controls the pressure from atmospheric pressure to 1000 Pa and then back to 100 Pa, with a temperature range of 120~260°C and a distillation time of 4.5 hours. The resulting first composite solvent is recycled, while the heavy oil and light asphaltene are retained, with masses of 16 kg and 11.8 kg, respectively.

[0161] The 67.2 kg of the second solid residue obtained after drying was dispersed in water, and then H was added. + A 40% acid solution was prepared using a mixture of sulfuric acid, acetic acid, and SP-type demulsifier (mass ratio of sulfuric acid, acetic acid, and SP-type demulsifier: 70:28:2). The reaction temperature was controlled at 38℃, and the reaction time was 1 hour. After the reaction, the aqueous solution (i.e., the first filtrate) and the third solid residue were separated by pressure filtration. The aqueous solution was pumped into a bubble bed reactor, and 5.7 kg of 20 wt% ammonia water and 4 kg of 15 wt% hydrogen peroxide were added to the reactor sequentially. A flow rate of 10 m³ / h was introduced into the reactor. 3 The air was supplied at a constant rate of 1 h, and the pH was controlled between 7 and 9. The oxidation reaction was carried out at room temperature for 2.5 h (with air continuously supplied during the reaction). After the reaction was completed, the material was placed in a storage tank and allowed to stand for 1.5 h. The lower precipitate obtained by separation was the nano-sized iron-based catalyst. A total of 11.1 kg of catalyst (dry basis) was collected.

[0162] The third solid residue collected by pressure filtration is added to the second composite solvent, which is a mixture of decrystalline anthracene oil, quinoline, tetrahydrofuran, and coal-based wash oil prepared in a mass ratio of 1:1:1:7. The resulting liquid-solid mixture is stirred at 150°C and 200 r / min for 1 hour. The material is then pumped into a screen filter at a pressure of 1.2 MPa and a filtration temperature of 220°C. The fourth solid residue separated by filtration is sent to a dryer for drying to recover the adsorbed and adhered second composite solvent and other liquids to obtain the fifth solid residue. The escaped gas is condensed to below 50°C in a condenser (condensing medium temperature between 30 and 120°C, for example, 40°C) and then sent to a distillation system together with the filtered liquid. Distillation separates the gas into the recovered second composite solvent and heavy asphaltene. Distillation separation was performed using a combination of atmospheric distillation and vacuum distillation. Atmospheric distillation began with a slow reduction in pressure at a distillation temperature of 100℃, and the distillation time was approximately 3 hours. Vacuum distillation involved controlling the pressure from atmospheric pressure to 1000 Pa and then back to 100 Pa, with a temperature range of 200–320℃ and a distillation time of 6.5 hours. The recovered second composite solvent was recycled, while the resulting heavy asphaltene (17.8 kg) was retained.

[0163] The obtained 47 kg of fifth solid residue was mixed with 20 kg of coal powder of four different particle sizes (0.425 mm to 0.9 mm), 34 kg of coal powder of four different particle sizes (0.15 to 0.425 mm), 12 kg of coal powder of four different particle sizes (0.075 to 0.15 mm), and 7 kg of coal powder of four different particle sizes (0.045 to 0.0755 mm), totaling 73 kg of coal powder from a certain long-flame coal in Xinjiang, as well as a mixture of 0.4 kg of sodium naphthalenesulfonate and polyacrylamide flocculant (the mass ratio of sodium naphthalenesulfonate and polyacrylamide flocculant was 1:2) as a coal-water slurry additive. A coal-water slurry product with an apparent viscosity of 1008.5 mPa·s, no anhydrous or precipitation after 24 hours, and a coal slurry concentration of 63.5 wt% was prepared, in which the fifth solid residue accounted for 39 wt% of the total mass fraction of the solid materials (the sum of solid residue and dry coal powder).

[0164] High-purity refined asphalt can be obtained by thermally mixing the recovered heavy oil (also known as heavy oil), light asphalt, and heavy asphalt in a mass ratio of 1:14:5. The property analysis results are shown in Table 2 below. The morphology of the prepared catalyst is shown in [Table 2]. Figure 2 .

[0165] Table 2. Property Analysis Results of High-Purity Refined Asphalt

[0166] As can be seen from Table 2, the high-purity asphalt prepared using the obtained heavy oil, light asphalt, and heavy asphalt has an extremely low ash content of only 0.0038 wt%, a quinoline insoluble content of only 1.81 wt%, and a toluene insoluble content of 21 wt%. This high-purity asphalt (ultra-low ash) containing a small amount of highly active components, a small amount of quinoline insolubles, and certain intermediate components is a high-quality raw material for the production of high-performance electrode carbon materials.

[0167] from Figure 2 It can be seen that the graded and graded utilization method of coal liquefaction products byproducts of coal and heavy oil hydrogenation in this embodiment can not only obtain nanoscale iron-based catalysts, but also the catalyst particles have the characteristics of rich apparent structure layers and wide distribution of active metal sites.

[0168] Example 2 This embodiment provides a method for graded and differentiated utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation, using coal liquefaction pitch byproducts of coal-oil co-refining as raw material. The basic properties of this raw material are shown in Table 3 below.

[0169] Table 3 Properties of Coal Liquefied Pitch By-products from Co-refining of Kerosene and Oil

[0170] The graded and graded utilization method for coal liquefaction products byproducts of coal and heavy oil hydrogenation is as follows: 100 kg of coal tar pitch, a byproduct of kerosene co-refining and crushed to less than 3 mm, was added to 450 kg of a first composite solvent, which was a mixture of coal-based light oil and toluene, wherein the mass ratio of coal-based light oil to toluene was 1:1, and the coal-based light oil was coal liquefaction light oil. The liquid-solid mixture was stirred at 60°C and 200 r / min for 1 hour. Then, the homogenized liquid-solid mixture was pumped into a centrifuge at 4000 r / min for separation. The residence time of the material in the centrifuge was approximately 10 minutes, yielding a first oil-liquid mixture solution and a first solid residue. The first solid residue separated by centrifugation is sent to a dryer for drying to recover the first composite solvent and other liquids adsorbed and adhered in the solid residue, resulting in a second solid residue. The escaped gas is condensed to below 50°C in a condenser (condensing medium temperature between 30~120°C, for example 40°C) and then sent together with the centrifuged liquid (i.e., the first solvent oil mixture) into a distillation system. Distillation separates it into the first composite solvent, heavy oil, and light asphaltene (the specific distillation method is the same as in Example 1—using atmospheric distillation followed by vacuum distillation. Atmospheric distillation begins with a slow reduction in pressure at a distillation temperature of 120°C, and the atmospheric distillation time is approximately 3.5 hours. The pressure control range for vacuum distillation is from atmospheric pressure to 1000 Pa and then back to 100 Pa, and the temperature control range for vacuum distillation is 120~260°C). The vacuum distillation time is 5 hours. The obtained first composite solvent is recycled, while the obtained heavy oil and light asphaltene are retained, with masses of 32.1 kg and 4.8 kg, respectively.

[0171] The 67.2 kg of the second solid residue obtained after drying was dispersed in water, followed by the addition of a 40% (w / w) acid solution. This acid solution was a mixture of sulfuric acid, phosphoric acid, and SP-type demulsifier (mass ratio of sulfuric acid, phosphoric acid, and SP-type demulsifier: 50:48:2). The reaction temperature was controlled at 45°C, and the reaction time was 2 hours. After the reaction, the aqueous solution (i.e., the first filtrate) and the third solid residue were separated by pressure filtration. The aqueous solution was pumped into a bubble bed reactor, and 8.7 kg of 20 wt% ammonia water and 3 kg of 15 wt% hydrogen peroxide were added sequentially. A flow rate of 12 m³ / h was introduced into the reactor. 3 The air was supplied at a constant rate of 1 h, and the pH was controlled between 7 and 9. The oxidation reaction was carried out at room temperature for 1.5 h (with air continuously supplied during the reaction). After the reaction was completed, the material was placed in a storage tank and allowed to stand for 2.0 h. The lower precipitate obtained by separation was the nano-sized iron-based catalyst. A total of 18.3 kg of catalyst was collected.

[0172] The third solid residue is then added to the second composite solvent, which is a mixture of decrystalline anthracene oil, tetrahydrofuran, and coal-based wash oil in a mass ratio of 1:1:8. The resulting liquid-solid mixture is stirred at 160°C and 200 r / min for 1 hour. The material is then pumped into a filter screen at a pressure of 1.2 MPa and a filtration temperature of 220°C. The filtered fourth solid residue is then dried in a dryer to recover the adsorbed and adhered second composite solvent and other liquids, yielding a fifth solid residue. The escaped gas is condensed to below 50°C in a condenser (condensing medium temperature between 30 and 120°C, for example, 40°C) and then sent to a distillation system along with the filtered liquid. Distillation separates the gas into the recovered second composite solvent and heavy asphaltene. Distillation separation was performed using a combination of atmospheric distillation and vacuum distillation. Atmospheric distillation began with a slow reduction in pressure at a distillation temperature of 100℃, and the distillation time was approximately 3 hours. Vacuum distillation involved controlling the pressure from atmospheric pressure to 1000 Pa and then back to 100 Pa, with the temperature ranged from 200 to 320℃, and the distillation time was 7 hours. The recovered second composite solvent was recycled, while the resulting heavy asphaltene (16.7 kg) was retained.

[0173] Approximately 35 kg of solid slag insoluble in the second composite solvent (i.e., the fifth solid slag) was mixed with 55 kg of coal powder from a certain Yulin coal source with four different particle sizes: 16 kg of coal powder with a particle size of 0.425 mm-0.9 mm, 24 kg of coal powder with a particle size of 0.15-0.425 mm, 9 kg of coal powder with a particle size of 0.075-0.15 mm, and 5 kg of coal powder with a particle size of 0.045-0.075 mm. A mixture of 0.2 kg of sodium lignosulfonate and polyacrylamide flocculant (mixed at a mass ratio of 1:2) was also used as an additive for coal-water slurry preparation. This resulted in a coal-water slurry product with an apparent viscosity of 1031.6 mPa·s, no anhydrous or precipitate after 48 hours, and a slurry concentration of 62.1 wt%. The fifth solid slag accounted for 38.89 wt% of the total solid material (the sum of solid slag and dry coal powder).

[0174] Example 3 This embodiment provides a method for graded and graded utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation. The method uses pitch produced by a continuous experimental device for coal tar hydrogenation, and its basic properties are shown in Table 4 below.

[0175] Table 4 Properties of components in hydrogenated coal tar asphalt enrichment

[0176] The graded and graded utilization method for coal liquefaction products byproducts of coal and heavy oil hydrogenation is as follows: 100 kg of coal tar pitch, a byproduct of coal tar hydrogenation and crushed to less than 3 mm, was added to 400 kg of a first composite solvent, which was a mixture of coal-based light oil and toluene, wherein the mass ratio of coal-based light oil to toluene was 1:1, and the coal-based light oil was coal liquefaction light oil. The liquid-solid mixture was stirred at 50°C and 200 r / min for 1 hour. Then, the homogenized liquid-solid mixture was pumped into a centrifuge at 4000 r / min for separation. The residence time of the material in the centrifuge was approximately 10 minutes, yielding a first oil-liquid mixture solution and a first solid residue. The first solid residue separated by centrifugation is sent to a dryer for drying to recover the first composite solvent and other liquids adsorbed and adhered in the solid residue, resulting in a second solid residue. The escaped gas is condensed to below 50°C in a condenser (condensing medium temperature between 30~120°C, for example 40°C) and then sent together with the centrifuged liquid (i.e., the first solvent oil mixture) into a distillation system. Distillation separates it into the first composite solvent, heavy oil, and light asphaltene (the specific distillation method is the same as in Example 1—using atmospheric distillation followed by vacuum distillation. Atmospheric distillation begins with a slow reduction in pressure at a distillation temperature of 120°C, and the atmospheric distillation time is approximately 3.5 hours. The pressure control range for vacuum distillation is from atmospheric pressure to 1000 Pa and then back to 100 Pa, and the temperature control range for vacuum distillation is 120~260°C). The vacuum distillation time is 5.5 hours. The obtained first composite solvent is recycled, while the obtained heavy oil and light asphaltene are retained, with masses of 27.3 kg and 7.1 kg, respectively.

[0177] The 65.6 kg of the second solid residue obtained after drying was dispersed in water, followed by the addition of a 40% (w / w) acid solution. This acid solution was a mixture of sulfuric acid, acetic acid, and SP-type demulsifier (mass ratio of sulfuric acid, acetic acid, and SP-type demulsifier: 80:17:3). The reaction temperature was controlled at 32℃, and the reaction time was 3 hours. After the reaction, the aqueous solution (i.e., the first filtrate) and the third solid residue were separated by pressure filtration. The aqueous solution was pumped into a bubble bed reactor, and 5.7 kg of 20 wt% ammonia water and 50 g of 15 wt% hydrogen peroxide were added sequentially to the reactor. A flow rate of 11.5 m³ / h was introduced into the reactor. 3 The air was supplied at a constant rate of 1 h, and the pH was controlled between 7 and 9. The oxidation reaction was carried out at room temperature for 2 h (with air continuously supplied during the reaction time). After the reaction was completed, the material was placed in a storage tank and allowed to stand for 2.0 h. The lower precipitate obtained by separation was the nano-sized iron-based catalyst. A total of 25.4 kg of catalyst was collected.

[0178] The collected insoluble solid residue (i.e., the third solid residue) was dispersed and then added to the second composite solvent, which was a mixture of four solvents—decrystalline anthracene oil, tetrahydrofuran, coal-based wash oil, and quinoline—in a mass ratio of 1:2.5:6:0.5. The resulting liquid-solid mixture was stirred at 160°C and 200 r / min for 1 hour. The material was then pumped into a filter screen at a pressure of 1.5 MPa and a filtration temperature of 200°C. The filtered fourth solid residue was sent to a dryer for drying to recover the adsorbed and adhered second solvent and other liquids, resulting in the fifth solid residue. The escaped gas was condensed to below 50°C in a condenser (condensing medium temperature between 30 and 120°C, for example, 40°C) and then sent to a distillation system along with the centrifuged liquid. Distillation separated the gas into the recovered second composite solvent and heavy asphaltene. Distillation separation was performed using a combination of atmospheric distillation and vacuum distillation. Atmospheric distillation began with slow depressurization at a distillation temperature of 100℃, and the distillation time was approximately 3 hours. Vacuum distillation involved controlling the pressure from atmospheric pressure to 1000 Pa and then back to 100 Pa, with the temperature ranged from 200 to 320℃, and the distillation time was 6 hours. The recovered second composite solvent was recycled, while the resulting heavy asphaltene (15.6 kg) was retained.

[0179] Approximately 34 kg of solid slag insoluble in the second composite solvent (i.e., the fifth solid slag) was mixed with 53 kg of coal powder from a certain type of Yulin coal with four different particle sizes: 15 kg of coal powder with a particle size of 0.425-0.9 mm, 24 kg of coal powder with a particle size of 0.15-0.425 mm, 9 kg of coal powder with a particle size of 0.075-0.15 mm, and 5 kg of coal powder with a particle size of 0.045-0.0755 mm, as well as a mixture of 0.18 kg of sodium naphthalenesulfonate and polyacrylamide flocculant (the mass ratio of sodium naphthalenesulfonate and polyacrylamide flocculant was 1:1) as a coal-water slurry additive. A coal-water slurry product with an apparent viscosity of 1031.6 mPa·s, no anhydrous or precipitate after 48 h, and a coal slurry concentration of 62.1 wt% was prepared. The fifth solid slag accounted for 39.08 wt% of the total mass of solid materials (the sum of solid slag and dry coal powder).

[0180] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0181] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0182] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for graded and differentiated utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation, characterized in that, include: The coal liquefaction products are dissolved in a first composite solvent under a first stirring condition, followed by a first solid-liquid separation to obtain a first agent-oil mixture solution and a first solid residue; the coal liquefaction products include at least one of direct coal liquefaction residue, coal liquefaction pitch, coal-oil co-refining residue, and coal tar hydrogenation residue; the first composite solvent includes at least one of coal-based light oil, benzene, toluene, xylene, petroleum ether, and tetrahydrofuran. The first solid residue is subjected to a first drying process to obtain a second agent-oil mixture solution and a second solid residue. The first agent-oil mixture and the second agent-oil mixture are mixed and then subjected to a first distillation to obtain the recovered first composite solvent, heavy oil and light asphalt. The second solid residue is reacted with an acidic aqueous solution in a first reaction, followed by a second solid-liquid separation to obtain a first filtrate and a third solid residue; the reaction temperature of the first reaction is room temperature - 300℃; The first filtrate is subjected to an oxidation reaction with an oxygen source and an alkaline source to obtain a nano-sized iron-based catalyst; the reaction temperature of the oxidation reaction is room temperature to 180℃, and the reaction time of the oxidation reaction is 0.1-4h. The third solid residue is dissolved in the second composite solvent, followed by a fourth solid-liquid separation to obtain a third agent-oil mixture solution and a fourth solid residue; the second composite solvent includes at least one of coal-based wash oil distillate, decrystalline anthracene oil, coal liquefaction middle distillate, tetrahydrofuran, quinoline, N,N-dimethylformamide, and N,N-dimethylpyrrolidone. The fourth solid residue is subjected to a second drying process to obtain a fourth agent-oil mixture solution and a fifth solid residue. The third and fourth oil mixtures are subjected to a second distillation to obtain the recovered second composite solvent and heavy asphaltene. The heavy oil, the light asphalt, and the heavy asphalt are first mixed to obtain high-purity asphalt; The fifth solid slag, coal powder, and coal-water slurry additives are mixed in a second batch to obtain the coal-water slurry product.

2. The graded and quality-based utilization method according to claim 1, characterized in that, The oxygen source includes at least one of air, oxygen, and hydrogen peroxide; And / or, the alkali source includes an alkaline solution or an alkaline gas; And / or, the amount of the alkali source used is such that the pH of the reaction liquid for the oxidation reaction is controlled to be 6.5-13; And / or, the method for graded and classified utilization of coal and heavy oil hydrogenation by-products of coal liquefaction further includes a third solid-liquid separation step after the oxidation reaction.

3. The graded and quality-based utilization method according to claim 2, characterized in that, Alkaline solutions include at least one of sodium hydroxide solution, calcium hydroxide solution, and ammonia solution; And / or, the alkaline gas includes at least one of ammonia or ammonia-containing water vapor; And / or, the third solid-liquid separation method includes static separation or centrifugal separation, and the centrifugal separation speed is 200-5000 r / min.

4. The graded and quality-based utilization method according to claim 2, characterized in that, The alkaline solution includes Lewis bases.

5. The graded and quality-based utilization method according to claim 1, characterized in that, The acid-containing aqueous solution is an acid solution, or an acid solution and a demulsifier.

6. The graded and quality-based utilization method according to claim 5, characterized in that, The acid solution includes at least one of formic acid, acetic acid, hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, and citric acid; And / or, the concentration of the acid solution is 1-80 wt%; And / or, the demulsifier includes at least one of sodium hexametaphosphate, SP type demulsifier, AP type demulsifier, and AE type demulsifier; And / or, the demulsifier in the acidic aqueous solution has a mass content of 0.1-15%.

7. The graded and quality-based utilization method according to claim 1, characterized in that, The mass ratio of the first composite solvent to the coal liquefaction product is (1-20):1; And / or, the first stirring rate is 20-400 r / min, the first stirring temperature is 30-250℃, and the first stirring time is 0.5-3 h.

8. The graded and quality-based utilization method according to claim 1, characterized in that, The first solid residue is subjected to a first drying process to obtain a second oil-based mixed solution and a second solid residue, comprising: The first solid residue is first dried, and the gas that escapes during the first drying process is first condensed and collected to obtain the second agent oil mixture solution. The first dried solid is dispersed to obtain the second solid residue; And / or, the first distillation includes a first primary distillation and a first vacuum distillation performed sequentially; And / or, the method for graded and classified utilization of coal and heavy oil hydrogenation by-product coal liquefaction products further includes the step of recycling the recovered first composite solvent.

9. The graded and quality-based utilization method according to claim 8, characterized in that, The temperature for the first drying step is 90-300℃; And / or, the temperature of the first condensation is room temperature - 150°C; And / or, the distillation temperature of the material in the first primary distillation column is the initial boiling point -250°C, and the time of the first primary distillation is 0.5-12h; And / or, the pressure of the first vacuum distillation is 10-1000 Pa, the temperature of the first vacuum distillation is 50-300 °C, and the time of the first vacuum distillation is 0.5-12 h.

10. The graded and quality-based utilization method according to claim 1, characterized in that, The high-purity asphalt refers to asphalt with an ash content of less than 50 ppm.

11. The graded and quality-based utilization method according to claim 1, characterized in that, The fourth solid-liquid separation method employs either filter screen filtration or centrifugal separation. And / or, the temperature of the second drying is 200-350°C; And / or, subjecting the fourth solid residue to a second drying process to obtain a fourth agent-oil mixture solution and a fifth solid residue, comprising: The fourth solid residue is subjected to a second drying process, and the gas that escapes during the second drying process is collected after a second condensation to obtain a fourth agent oil mixed solution. The fifth solid residue is obtained by dispersing the second dried solid. And / or, the second distillation includes a second primary distillation and a second vacuum distillation performed sequentially.

12. The graded and quality-based utilization method according to claim 11, characterized in that, The fourth solid-liquid separation method uses a filter screen, and the pressure during the filter screen filtration is 0.2-5MPa, and the temperature is 150-350℃. And / or, the distillation temperature of the material in the second primary distillation column is the initial boiling point -150°C, and the time of the second primary distillation is 0.5-12 hours; And / or, the pressure of the second vacuum distillation is 10-1000 Pa, the temperature of the second vacuum distillation is 50-350 °C, and the time of the second vacuum distillation is 0.5-12 h; And / or, the temperature of the second condensation is room temperature - 150°C.

13. The graded and quality-based utilization method according to claim 1, characterized in that, The ash content of the heavy asphalt is 1-150 ppm; And / or, the coal powder includes coal powder of different particle size grades; And / or, the mass ratio of the fifth solid slag, the pulverized coal, and the coal-water slurry additive is (1-2):(2-8):(0.001-0.04). And / or, the concentration of the fifth solid slag is 20-50 wt%; And / or, the method for graded and classified utilization of coal liquefaction products byproducts of coal and heavy oil hydrogenation further includes the step of selling the heavy oil as a solvent oil or a product, and / or, the step of using at least one of the heavy oil, light asphaltene, and heavy asphaltene in the production of high-end carbon materials or selling it as a product.

Images