Catalytic coal-oil slurry and method for its preparation, method for direct coal liquefaction, and use

Abstract

The present invention relates to the field of direct coal liquefaction, and discloses a catalytic coal-oil slurry and its preparation method, method of direct coal liquefaction, and use. The method includes mixing an oil-soluble molybdenum source, a solvent, pulverized coal, and an optional sulfur source to obtain the catalytic coal-oil slurry. When the catalytic coal-oil slurry is used for direct coal liquefaction, it can achieve a higher oil yield and reduce the production cost.

Description

Detailed Description of the Invention

[0001] [Technical field] The present invention relates to the technical field of direct coal liquefaction, in particular to a catalyst oil-coal slurry and its preparation method, method for direct coal liquefaction, and use.

[0002] 〔background〕 Direct coal liquefaction is a clean coal technology that converts coal into liquid products by injecting hydrogen into the molecular structure of coal and its derivatives under high temperature and pressure conditions with the assistance of hydrogen donor solvents and catalysts. At the beginning of the development of direct liquefaction, the two important influencing factors of coal liquefaction catalysts and pre-hydrogenation of solvents were not found to promote coal liquefaction, so the reaction conditions of coal liquefaction at that time were quite severe, and the reaction pressure was as high as 70 MPa. For more than 100 years since the development of direct coal liquefaction, research in various countries has begun to pay attention to the use of catalysts and solvent hydrogenation technology, and thus the reaction conditions tend to be relaxed. However, the current direct coal liquefaction technology still faces the problems of low oil yield and high production costs caused by low oil yield. Therefore, it is urgent to develop a direct coal liquefaction technology that can significantly improve the oil yield.

[0003] 〔overview〕 The object of the present invention is to overcome the above-mentioned problems existing in the prior art and provide a catalytic oil-coal slurry and its preparation method, and a method for direct coal liquefaction and its use. The use of the catalytic oil-coal slurry in direct coal liquefaction can obtain a higher oil yield and reduce the production cost.

[0004] In order to achieve the above object, a first aspect of the present invention is a method for preparing a catalyst oil-coal slurry, comprising the steps of: The method includes the step of combining an oil soluble molybdenum source, a solvent, coal powder, and an optional sulfur source to obtain the catalyst oil-coal slurry.

[0005] A second aspect of the present invention is a process for producing a sulphur-based oil-soluble catalyst comprising an oil-soluble molybdenum source, a solvent, coal powder and an optional sulphur source. or There is provided a catalyst oil-coal slurry prepared by the method according to the first aspect.

[0006] In a third aspect, the present invention relates to a process for producing a catalyst oil-coal slurry according to the second aspect, the process comprising the steps of: subjecting the catalyst oil-coal slurry according to the second aspect to direct coal liquefaction; or subjecting the coal powder to direct coal liquefaction in the presence of a solvent, an oil soluble molybdenum source, and an optional sulfur source; The present invention provides a method for direct coal liquefaction, comprising:

[0007] In a fourth aspect, the present invention provides the use of a catalyst oil-coal slurry according to the second aspect, or a method according to the first aspect, in direct coal liquefaction.

[0008] Through the above technical solutions, the present invention can achieve the following beneficial effects:

[0009] 1. Compared with the prior art, in the catalyst oil-coal slurry provided by the present invention, the catalyst is highly dispersed therein, has better dispersibility under liquefaction conditions, and is highly supported on coal powder. After being converted to molybdenum disulfide, the catalyst has higher activity, can better catalyze the reaction, and can effectively prevent the aggregation of polymer during the reaction.

[0010] 2. Compared with the existing iron-based catalyst, under the same liquefaction conditions, by using the catalytic oil-coal slurry provided by the present invention for direct coal liquefaction, the oil yield can be increased by about 10 percentage points, and the conversion rate is also significantly improved, thereby reducing the production cost.

[0011] 3. In particular, when the oil-soluble molybdenum source is molybdenum dialkyldithiophosphate and molybdenum dialkyldithiocarbamate, the above two substances are commonly used lubricating oil additives that are cheap and do not require additional sulfur sources, which can reduce the complexity of the operation and further reduce the production cost.In addition, when the oil-soluble molybdenum source is molybdenum dialkyldithiocarbamate, the use of phosphorus is avoided, thus further reducing the pollution to the environment, and the chemical stability is better, which is more advantageous than direct liquefaction reaction.

[0012] Detailed Description The range endpoints and any values ​​disclosed herein are not intended to be limited to the precise range or value, and the range endpoints and any values ​​should be understood to include values ​​that are close to the range or value. For ranges of values, each range endpoint and each range endpoint and each individual point value can be combined with each other to produce one or more new value ranges, and these value ranges should be considered as specifically disclosed herein.

[0013] In a first aspect, the present invention provides a method for preparing a catalyst oil-coal slurry comprising: The method includes the step of combining an oil soluble molybdenum source, a solvent, coal powder, and an optional sulfur source to obtain the catalyst oil-coal slurry.

[0014] Current direct coal liquefaction technology still faces the problems of low oil yield and high production cost.

[0015] In the course of research, the inventors of the present invention have found that the use of the above-mentioned method for preparing catalytic oil-coal slurry, especially the use of the above-mentioned oil-soluble molybdenum source as catalyst, not only avoids the problems of high water consumption and complicated preparation steps in the preparation of conventional water-soluble and highly dispersed catalysts, but also avoids the problems of large particle size and poor dispersibility of powdered inorganic catalysts. The oil-soluble molybdenum source is highly dispersed in the catalytic oil-coal slurry, highly supported on the coal powder, and converted into ultrafine catalytic molybdenum disulfide under liquefaction conditions, which has better activity and can exert higher hydrogenation catalytic activity, thus obtaining higher oil yield and conversion rate, and effectively preventing macromolecular agglomeration during the reaction. In addition, depending on the specific oil-soluble molybdenum source used, it can be determined whether to add a sulfur source. Furthermore, the inventors of the present invention have also found that the use of the above-mentioned catalytic oil-coal slurry can obtain a significantly higher oil yield under the same liquefaction conditions than the catalytic oil-coal slurry using an iron-based catalyst.

[0016] According to the present invention, preferably, the amount of the oil-soluble molybdenum source based on elemental molybdenum is 0.005-1 part by weight, preferably 0.1-0.3 parts by weight, more preferably 0.2-0.25 parts by weight, based on 100 parts by weight of coal powder. The inventors of the present invention found in their research that when the above range is satisfied, a significantly high catalytic effect can be obtained, and a higher oil yield and conversion rate can be obtained.

[0017] According to the present invention, the oil-soluble molybdenum source is preferably selected from at least one of molybdenum phosphate, molybdenum hexacarbonyl, molybdenum naphthenate, molybdenum carboxylate, molybdenum sulfonate, molybdenum hydroxythiol, and molybdenum xanthate. More preferably, the oil-soluble molybdenum source is at least one of molybdenum dialkyldithiophosphate (a type of molybdenum phosphate), molybdenum dialkyldithiocarbamate (a type of molybdenum carboxylate), molybdenum hexacarbonyl, and molybdenum naphthenate, more preferably at least one of molybdenum dialkyldithiophosphate (MoDTP) and molybdenum dialkyldithiocarbamate (MoDTC).

[0018] It should be understood that naphthenic acid is a mixture of organic acids in the form of a dark oil separated from petroleum products during refining, and the corresponding prepared molybdenum naphthenate is also a mixture, and the molybdenum naphthenate is mainly a carboxyl derivative of a five-membered carbon ring. In addition, in molybdenum dialkyldithiocarbamates, different lengths of the alkyl carbon chain correspond to different specific substances, and the same is true for molybdenum dialkyldithiophosphates, i.e., in molybdenum dialkyldithiophosphates, different lengths of the alkyl carbon chain correspond to different specific substances. For molybdenum dialkyldithiocarbamates, when the alkyl carbon chain has fewer carbon atoms (e.g., 2-6, e.g., 3, 4, or 5), the substance is generally in the form of a powder (solid), and when the alkyl carbon chain has a higher number of carbon atoms (e.g., 12-14), the substance is generally in the form of an oil (liquid). Molybdenum dialkyldithiophosphates are generally in the form of an oil (liquid). Liquid molybdenum dialkyldithiocarbamates are even more preferred.

[0019] The inventors of the present invention have found in their research that the use of oil-soluble molybdenum sources as described above can achieve better catalytic effect and obtain higher oil yield. In particular, molybdenum dialkyldithiophosphate or molybdenum dialkyldithiocarbamate is a component commonly used in lubricating oil, which is inexpensive and can reduce production costs, and can also be directly decomposed to form MoS2, which has direct catalytic effect under liquefaction conditions without the need to add additional sulfur for sulfurization, making production operations simpler and more cost-effective. The inventors of the present invention have further found in their research that when liquid molybdenum dialkyldithiocarbamate is used, not only can it obtain better dispersion effect and higher oil yield, but it can also avoid the use of phosphorus, further reducing the impact on the environment.

[0020] According to the present invention, the amount of the solvent is preferably 80 to 220 parts by weight, preferably 100 to 190 parts by weight, more preferably 120 to 150 parts by weight, relative to 100 parts by weight of coal powder.

[0021] According to the present invention, preferably, the solvent is a hydrogen donor solvent, and the hydrogen donor solvent has a viscosity of 0.98 g cm -3 Lower than 20 , 5mm 2 The hydrogen donor solvent has a kinematic viscosity at 40° C. lower than 1 / s and a molar ratio of H to C higher than 0.25. The hydrogen donor solvent refers to a solvent that can dissolve coal during the coal liquefaction process (i.e., swell the coal and then form a homogeneous oil-coal slurry with the hydrogen donor solvent) and supply and transport hydrogen by diffusing it to the surface of the coal or catalyst, and the solvent also has the effect of preventing polycondensation of free radical fragments due to thermal decomposition of coal.

[0022] The hydrogen donor solvent may include one or more of tetrahydronaphthalene, dihydrophenanthrene, and dihydroanthracene. In direct coal liquefaction, the hydrogen donor solvent used may generally be the self-generated circulating solvent of direct coal liquefaction, for example, in CN104893751A, partially liquefied oil was used as the circulating solvent. It should be understood that during the continuous operation of the direct coal liquefaction device, the mixed oil of medium viscosity oil and heavy oil generated by direct coal liquefaction itself is called the self-generated circulating solvent of direct coal liquefaction. The use of such a solvent not only plays the role of hydrogen donor solvent, but also can reuse materials and avoid waste. ρ 20 refers to the density measured at 20°C, and the kinematic viscosity is measured by the method in GB / T265-1988. The molar ratio of H to C is an indicator of the hydrogen content of the solvent, and the higher the ratio, the stronger the hydrogen donating ability.

[0023] The use of the solvent as mentioned above can further improve the dispersibility of the oil-soluble molybdenum source in the catalyst oil-coal slurry, and further control the concentration of each material within a more suitable range, thereby further improving the oil yield.

[0024] According to the present invention, the sulfur source is a sulfur-containing substance that can convert the oil-soluble molybdenum source into a sulfur-containing substance (e.g., molybdenum disulfide). Therefore, when the oil-soluble molybdenum source itself contains sulfur and can convert the oil-soluble molybdenum source into molybdenum disulfide (especially under direct coal liquefaction conditions), there is no need to additionally introduce a sulfur source. Preferably, the amount of the sulfur source is such that the molar ratio of the sulfur element to the molybdenum element in the catalyst oil-coal slurry is 0-3.5, preferably 2-2.8, more preferably 2.2-2.5. It should be understood that the oil-soluble molybdenum source may also contain sulfur element, and the amount of the sulfur source is based on the principle that the molar ratio of the total amount of the sulfur element to the molybdenum element in the catalyst oil-coal slurry satisfies the above molar ratio.

[0025] According to the invention, preferably, the sulfur source is selected from at least one of elemental sulfur, inorganic sulfur, and organic sulfur, preferably from at least one of sulfur, carbon disulfide, sodium sulfide, and sodium hydrosulfide.

[0026] Here, the order of mixing the oil-soluble molybdenum source, the solvent, the coal powder, and the optional sulfur source is not particularly limited, as long as the oil-soluble molybdenum source can be dispersed as much as possible and the material can be made as uniform as possible. However, preferably, the method includes a step of first mixing the oil-soluble molybdenum source and the solvent, and then mixing with the coal powder to obtain the catalytic oil-coal slurry with or without adding the sulfur source. In their research, the inventors of the present invention found that the step of first mixing the oil-soluble molybdenum source and the solvent can make the oil-soluble molybdenum source more uniformly dispersed in the catalytic oil-coal slurry, thereby obtaining a higher oil yield.

[0027] In the present invention, there is no particular limitation on the coal powder, and the coal powder may be coal from various sources. The inventors of the present invention have found that the method of the present invention can achieve good conversion effect for coal powder with low vitrinite content, such as coal with vitrinite content of 40-48 wt% (e.g., 42 wt%, 44 wt%, or 46 wt%). It should be understood that coal generally includes vitrinite, inertinite, and exinite. Vitrinite has high oxygen content, low carbon content, and moderate hydrogen content. During hydroliquefaction, vitrinite is easier to liquefy than the other two, and thus the vitrinite content can generally characterize the difficulty of coal liquefaction. In general, the higher the vitrinite content in the coal powder, the easier it is to liquefy. In the prior art, it is generally desired to use coal powder with a higher vitrinite content. The method of the present invention can achieve good conversion effects not only for coal powders with higher vitrinite contents, but also for coal powders with lower vitrinite contents (e.g., vitrinite contents of 40-48% by weight) which are difficult to convert in the prior art.

[0028] In a second aspect, the present invention provides a process for producing a soluble molybdenum extractant comprising an oil soluble molybdenum source, a solvent, coal powder, and an optional sulfur source. or Provided is a catalyst oil-coal slurry prepared by the method according to the first aspect, in which the amounts and types of each raw material are as described above and will not be repeated here.

[0029] In a third aspect, the present invention relates to a process for producing a catalyst oil-coal slurry according to the second aspect, the process comprising the steps of: subjecting the catalyst oil-coal slurry according to the second aspect to direct coal liquefaction; or subjecting the coal powder to direct coal liquefaction in the presence of a solvent, an oil soluble molybdenum source, and an optional sulfur source; In this embodiment, the amount and type of each feedstock are as described above and will not be repeated here.

[0030] According to the present invention, when carrying out direct coal liquefaction, the direct coal liquefaction conditions can be adopted as those commonly used in the art, such as those disclosed in CN104893751A and CN100381540C. In one embodiment, the conditions for direct coal liquefaction include a pressure of 18-22 MPa (e.g., a pressure of 20 MPa), a temperature of 435-475°C (e.g., a temperature of 450°C or 460°C), and a reaction time of 0.5-1.5 hours (e.g., a reaction time of 1 hour). Direct coal liquefaction is generally carried out in the presence of hydrogen, and the amount of hydrogen makes the pressure fall within the above range.

[0031] In a fourth aspect, the present invention provides the use of a catalyst oil-coal slurry according to the second aspect, or a method according to the first aspect, in direct coal liquefaction.

[0032] According to a particularly preferred embodiment of the present invention, mixing liquid molybdenum dialkyldithiocarbamate thoroughly with a solvent, stirring them uniformly, then adding coal powder into the mixture, adding sulfur, mixing them thoroughly, stirring them uniformly to obtain a catalytic oil-coal slurry, in which for 100 parts by weight of coal powder, the amount of the oil-soluble molybdenum source based on molybdenum element is 0.24-0.25 parts by weight, the amount of the solvent is 125-140 parts by weight, and the sulfur is added in an amount such that the molar ratio of sulfur to molybdenum in the catalytic oil-coal slurry is 2.25-2.35; adding the catalyst oil-coal slurry to a reactor, adding hydrogen, and setting the reaction pressure at 19-20 MPa, the reaction temperature at 455-460°C, and the reaction time at 1-1.3 hours; According to the method, a catalyst oil-coal slurry is prepared and direct coal liquefaction is carried out.

[0033] The present invention will be described in detail by the following examples. The coal powder in Examples 1-11 is Shendong coal, and more than 80% of it has a particle size less than 200 mesh.

[0034] [Table 1]

[0035] In Table 1, the symbols have the following meanings:

[0036] Part of technical analysis:Mad refers to moisture content on air dry basis;Ad refers to ash on dry basis;Vdaf refers to volatiles on dry ashless basis. Determined according to the methods in GB / T211-2017 and GB / T212-2008.

[0037] Elemental analysis part: FC daf refers to the fixed carbon on a dry ash-free basis. C, H, O, N, and S refer to the contents of each element, respectively. Determined according to the methods in GB / T214-2007, GB / T476-2008, and GB / T19227-2008.

[0038] Petrographic analysis part:Vitrinite refers to the vitrinite content.Inertinite refers to the inertinite content.Ecdinite refers to the ecdinite content.Measured according to the method in GB / T8899-2013.

[0039] The solvents in Examples 1 to 11 were self-generated circulating solvents for direct coal liquefaction, and the main properties of the solvents are shown in Table 2.

[0040] [Table 2]

[0041] <Example 1> Description of the method for preparing catalyst oil-coal slurry provided by the present invention The liquid molybdenum dialkyldithiophosphate (with a molybdenum content of 10.45% by weight, the carbon atoms in the alkyl carbon chain were 13) and the solvent were thoroughly mixed and stirred uniformly, then the coal powder was added into the mixture, sulfur was added, and then the mixture was thoroughly mixed and stirred uniformly to obtain a catalytic oil-coal slurry, where for 100 parts by weight of the coal powder, the amount of the oil-soluble molybdenum source based on elemental molybdenum was 0.22 parts by weight, the amount of the solvent was 150 parts by weight, and sulfur was added in an amount such that the molar ratio of elemental sulfur to elemental molybdenum in the catalytic oil-coal slurry was 2.2.

[0042] <Example 2> Description of the method for preparing catalyst oil-coal slurry provided by the present invention The liquid molybdenum dialkyldithiocarbamate (10.45 wt. % molybdenum content, the carbon atoms in the alkyl carbon chain were 13) and the solvent were thoroughly mixed and stirred uniformly, then the coal powder was added into the mixture, the carbon disulfide was added, and the mixture was thoroughly mixed and stirred uniformly to obtain a catalytic oil-coal slurry, where, for 100 wt. parts of coal powder, the amount of the oil-soluble molybdenum source based on elemental molybdenum was 0.2 wt. parts, the amount of the solvent was 120 wt. parts, and sulfur was added in an amount such that the molar ratio of elemental sulfur to elemental molybdenum in the catalytic oil-coal slurry was 2.5.

[0043] <Example 3> Description of the method for preparing catalyst oil-coal slurry provided by the present invention The liquid molybdenum dialkyldithiocarbamate (with a molybdenum content of 9.86% by weight, the carbon atoms in the alkyl carbon chain were 13) and the solvent were thoroughly mixed and stirred uniformly, then the coal powder was added into the mixture, the sulfur was added, and the mixture was thoroughly mixed and stirred uniformly to obtain a catalytic oil-coal slurry, where, for 100 parts by weight of the coal powder, the amount of the oil-soluble molybdenum source based on elemental molybdenum was 0.25 parts by weight, the amount of the solvent was 130 parts by weight, and the sulfur was added in an amount such that the molar ratio of elemental sulfur to elemental molybdenum in the catalytic oil-coal slurry was 2.3.

[0044] <Example 4> Description of the method for preparing catalyst oil-coal slurry provided by the present invention A catalyst oil-coal slurry was prepared according to the method of Example 3, with the difference that no sulfur source was added.

[0045] <Example 5> A catalyst oil-coal slurry was prepared according to the method of Example 3, except that the liquid molybdenum dialkyldithiocarbamate was replaced by molybdenum hexacarbonyl powder.

[0046] <Example 6> A catalyst oil-coal slurry was prepared according to the method of Example 3, except that the liquid molybdenum dialkyldithiocarbamate was replaced by molybdenum naphthenate powder.

[0047] <Example 7> A catalytic oil-coal slurry was prepared according to the method of Example 3, except that the amount of the oil-soluble molybdenum source based on elemental molybdenum was 0.1 parts by weight, the amount of the solvent was 100 parts by weight, and sulfur was added in an amount such that the molar ratio of elemental sulfur to elemental molybdenum in the catalytic oil-coal slurry was 2, relative to 100 parts by weight of coal powder.

[0048] <Example 8> A catalytic oil-coal slurry was prepared according to the method of Example 3, except that, per 100 parts by weight of coal powder, the amount of the oil-soluble molybdenum source based on elemental molybdenum was 0.3 parts by weight, the amount of the solvent was 190 parts by weight, and sulfur was added in an amount such that the molar ratio of elemental sulfur to elemental molybdenum in the catalytic oil-coal slurry was 2.8.

[0049] <Example 9> The catalyst oil-coal slurry was prepared according to the method of Example 3, except that the liquid molybdenum dialkyldithiocarbamate was replaced by powdered molybdenum dialkyldithiocarbamate (the number of carbon atoms in the alkyl carbon chain was 4).

[0050] <Example 10> The catalyst oil-coal slurry was prepared according to the method of Example 3, except that the liquid molybdenum dialkyldithiocarbamate, solvent, coal powder, and sulfur were mixed simultaneously.

[0051] <Example 11> A catalyst oil-coal slurry was prepared according to the method of Example 3, except that the liquid molybdenum dialkyldithiocarbamate was replaced by molybdenum butyrate powder.

[0052] <Example 12> The catalyst oil-coal slurry was prepared according to the method of Example 3, except that the solvent was tetrahydronaphthalene (its ρ 20 is 0.9659 g cm -3 The kinetic viscosity at 40°C is 1.8mm 2 / s and the molar ratio of H to C was 1.2).

[0053] <Comparative Example 1> The method in Example 3 was followed, with the difference that the liquid molybdenum dialkyldithiocarbamate was replaced by molybdenum trioxide powder (not oil soluble). The results are shown in Table 1.

[0054] <Comparative Example 2> The method in Example 3 was followed, with the difference that the liquid molybdenum dialkyldithiocarbamate was replaced by molybdenum disulfide powder (not oil soluble). The results are shown in Table 1.

[0055] <Comparative Example 3> The method in Example 3 was followed, with the difference that the liquid molybdenum dialkyldithiocarbamate was replaced by ammonium heptamolybdate powder (not oil soluble). The results are shown in Table 1.

[0056] <Comparative Example 4> 4.67g of iron-based catalyst (containing 3.97g of coal powder) was thoroughly mixed with 24.03g of coal powder, 42g of solvent, and 0.32g of sulfur, and stirred uniformly to obtain iron-based catalyst oil-coal slurry, i.e., for 100 parts by weight of coal powder, the amount of iron element was 1 part by weight, and the amount of the solvent was 150 parts by weight.

[0057] Here, the preparation method of iron-based catalyst was as follows: the raw coal was Shendong coal, more than 80% of which had a particle size less than 200 mesh, the solvent oil was the self-generated circulating solvent oil of direct coal liquefaction, and the precipitant was ammonia water. 49.64g of FeSO4·7H2O crystals were dissolved by 446.44g of deionized water at room temperature to prepare a specific aqueous solution, the solution was fully dissolved and stirred uniformly, and 158.864g of coal powder was added to the solution and stirred thoroughly to obtain a water-coal slurry with a coal powder concentration of about 24.12%. 24.272g of commercial ammonia water with a concentration of 26% by weight was added to 330.58g of deionized water to dilute the ammonia water with a concentration of about 1.71%. The water-coal slurry and the above dilute ammonia water were subjected to a neutralization reaction with co-flow and precipitation to produce an amorphous precipitate of ferrous iron, which was uniformly supported on the coal powder. The air flow rate was set to 1.456 L / min, and the aeration time was set to 1 hour. During the flow of oxygen, ammonia water was continuously added thereto by dropwise addition to ensure that the pH of the process was 7-7.5. Then, the slurry was centrifuged by a centrifuge, and the filter cake was placed in a 40°C blast drying oven and dried overnight. The obtained catalyst was crushed to less than 200 mesh for later use. The iron content in the catalyst was 6 wt%.

[0058] <Test Example 1> The same amount of catalyst oil-coal slurries prepared in Examples 1-11 and Comparative Examples 1-4 were taken, and direct coal liquefaction was carried out according to the following method: The catalyst oil-coal slurry was added to the reactor, hydrogen was added, the reaction pressure was set to 19 MPa, the reaction temperature was set to 455° C., and the reaction time was set to 1 hour.

[0059] After the reaction was completed, gas-phase and liquid-solid products were obtained. The composition of the gas-phase products was determined by gas chromatography. The liquid-solid products were subjected to Soxhlet extraction with n-hexane and tetrahydrofuran in turn, and the n-hexane solubles were defined as oil, and the tetrahydrofuran solubles were defined as asphaltenes and pre-asphaltenes. The residue of the tetrahydrofuran insolubles after drying and then calcining at 815°C in a muffle furnace for 6 hours was defined as residual ash (RA). The coal conversion (X), gas yield (G), hydrogen consumption (H), oil yield (O), and asphaltenes (including pre-asphaltenes and asphaltenes, A) yield were calculated according to the following formulas: X=1-(TI-RA) / F daf A=(HI-TI) / F daf H=(H0-H1) / F daf G=(G1-H1) / F daf O=X+HGWA Where: F daf : Coal mass on dry and ash-free basis, g; H0: mass of hydrogen charged in the reactor before the reaction, g; H1: mass of hydrogen remaining in the reactor after the reaction, g; G1: mass of gas in the reactor after the reaction, g; HI: mass of n-hexane insolubles, g; TI: mass of tetrahydrofuran insolubles, g; RA: mass of tetrahydrofuran insoluble residue after calcination, g; H: hydrogen consumption; G: gas yield; W: water yield, calculated by subtracting the oxygen element contained in the gas products CO and CO2 from the oxygen element in the coal / F daf ; A: Yield of asphaltene, difference between the mass of n-hexane insolubles and the mass of tetrahydrofuran insolubles / F daf ; O: oil yield.

[0060] The coal conversion and oil yield are shown in Table 3.

[0061] [Table 3]

[0062] From the results in Table 3, it can be seen that by using Examples 1-12 of the present invention, higher conversion rate and higher oil yield can be obtained, and the oil yield can be increased by about 10 percentage points compared to Comparative Examples 1-4. In addition, the molybdenum dialkyldithiocarbamate and molybdenum dialkyldithiophosphate used in Examples 1-4 are inexpensive, which can further reduce the production cost.

[0063] Moreover, the Shendong coal used above is a type of coal with low vitrinite content and difficult to liquefy. By using the technical solution of the present invention, a better conversion effect can be achieved for the Shendong coal which is difficult to liquefy, and when applied to other types of coal with higher vitrinite and easier to liquefy, a better conversion effect can be achieved.

[0064] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited thereto. Within the scope of the technical idea of ​​the present invention, various simple modifications can be made to the technical solutions of the present invention, including combining various technical features in any other suitable manner. These simple modifications and combinations should also be regarded as the contents disclosed in the present invention, and all belong to the protection scope of the present invention.

Claims

1. 1. A method for preparing a catalyst oil-coal slurry, comprising:

13. A method comprising the steps of: combining an oil soluble molybdenum source, a solvent, coal powder, and an optional sulfur source to obtain said catalytic oil-coal slurry.

2. the amount of the oil-soluble molybdenum source based on elemental molybdenum is 0.005 to 1 part by weight, preferably 0.1 to 0.3 parts by weight, more preferably 0.2 to 0.25 parts by weight, based on 100 parts by weight of coal powder; and / or 2. The method of claim 1, wherein the oil soluble molybdenum source is selected from at least one of molybdenum phosphate, molybdenum hexacarbonyl, molybdenum naphthenate, molybdenum carboxylate, molybdenum sulfonate, molybdenum hydroxythiol, and molybdenum xanthate, preferably at least one of molybdenum dialkyldithiophosphate, molybdenum dialkyldithiocarbamate, molybdenum hexacarbonyl, and molybdenum naphthenate, more preferably at least one of molybdenum dialkyldithiophosphate and molybdenum dialkyldithiocarbamate, and most preferably liquid molybdenum dialkyldithiocarbamate.

3. The amount of the solvent is 80 to 220 parts by weight, preferably 100 to 190 parts by weight, more preferably 120 to 150 parts by weight, based on 100 parts by weight of the coal powder; and / or The solvent is a hydrogen donor solvent, and the hydrogen donor solvent has a hydrogen donor capacity of 0.98 g cm －３ Lower than ２０ , 5mm ２ 2. The process of claim 1, wherein the copolymer has a kinematic viscosity at 40° C. lower than 1 / s and a molar ratio of H to C higher than 0.

25.

4. The amount of the sulfur source is such that the molar ratio of elemental sulfur to elemental molybdenum in the catalyst oil-coal slurry is 0 to 3.5, preferably 2 to 2.8, and more preferably 2.2 to 2.5; and / or 2. The method of claim 1, wherein the sulfur source is selected from at least one of elemental sulfur, inorganic sulfur, and organic sulfur, preferably at least one of sulfur, carbon disulfide, sodium sulfide, and sodium hydrosulfide.

5. 5. The method according to any one of claims 1 to 4, comprising the steps of first mixing the oil soluble molybdenum source with the solvent and then mixing with the coal powder to obtain the catalytic oil-coal slurry with or without the addition of the sulfur source.

6. an oil soluble molybdenum source, a solvent, coal powder, and an optional sulfur source; or A catalytic oil-coal slurry, characterized in that it is prepared by the method according to any one of claims 1 to 5.

7. the amount of the oil-soluble molybdenum source based on elemental molybdenum is 0.005 to 1 part by weight, preferably 0.1 to 0.3 parts by weight, more preferably 0.2 to 0.25 parts by weight, based on 100 parts by weight of coal powder; and / or 7. The catalyst oil-coal slurry according to claim 6, wherein the oil-soluble molybdenum source is selected from at least one of molybdenum phosphate, molybdenum hexacarbonyl, molybdenum naphthenate, molybdenum carboxylate, molybdenum sulfonate, molybdenum hydroxythiol, and molybdenum xanthate, preferably at least one of molybdenum dialkyldithiophosphate, molybdenum dialkyldithiocarbamate, molybdenum hexacarbonyl, and molybdenum naphthenate, more preferably at least one of molybdenum dialkyldithiophosphate and molybdenum dialkyldithiocarbamate, and most preferably liquid molybdenum dialkyldithiocarbamate.

8. subjecting the catalyst oil-coal slurry according to claim 6 or 7 to direct coal liquefaction; or subjecting the coal powder to direct coal liquefaction in the presence of a solvent, an oil soluble molybdenum source, and an optional sulfur source; 1. A method for direct coal liquefaction comprising:

9. 9. The method of claim 8, wherein the conditions for direct coal liquefaction include a pressure of 18-22 MPa, a temperature of 435-475°C, and a time of 0.5-1.5 hours.

10. Use of the catalyst oil-coal slurry according to claim 6 or the method according to any one of claims 1 to 5 in direct coal liquefaction.

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