A hydro-gasification process

Abstract

The present disclosure relates to a hydro-gasification method, which comprises: (1) using inert gas with a certain pressure to transport coal powder raw material to a gasification reaction device; (2) in the gasification reaction device, the coal powder raw material is subjected to a hydro-gasification reaction with hydrogen. In the hydro-gasification method provided by the present disclosure, the inert gas is used to replace high-pressure hydrogen to transport the coal powder, which can avoid the problem of "hydrogen brittleness" of the conveying pipeline, and can also avoid the problems of spontaneous combustion of the coal powder, explosion caused by static spark and the like; the coal powder raw material is replaced by methanol coal powder as the raw material, which can reduce the demand for hydrogen in the hydro-gasification process; the raw material is transported in a solid state, which can expand the conveying capacity range, reduce the number of reactor nozzles, and reduce the design difficulty of the hydro-gasification reaction device.

Description

Technical Field

[0001] This disclosure relates to the field of coal gasification technology, and more particularly to a hydrogenation gasification method. Background Technology

[0002] Typically, coal hydrogasification involves pressurizing pulverized coal of a specific particle size and feeding it into a hydrogasification reactor using high-pressure hydrogen. The pulverized coal reacts with the hydrogen gas introduced into the reactor, producing methane-rich gas, oil, and semi-coke. During this process, the pulverized coal is propelled through the pipeline by high-pressure hydrogen and controlled pressure differential.

[0003] However, there are the following risks in using hydrogen to transport pulverized coal: (1) Hydrogen molecules or atoms can enter the voids in the crystal lattice of many metals, causing stress concentration in the transition or defect areas of the material, resulting in plastic deformation and cracks, causing "hydrogen embrittlement". Long-term operation will lead to cracking and leakage of pulverized coal pipelines. (2) Hydrogen has a low density and is a flammable and explosive gas. During the transportation of pulverized coal, there may be a risk of spontaneous combustion of pulverized coal. (3) When using hydrogen gas pressure to transport pulverized coal, a long pipeline (>30 meters) is usually required to achieve stable flow. The long pipeline will lead to more bends in the pipeline. Pulverized coal is prone to stagnation at the bends, and there is also a risk of spontaneous combustion after coal is stopped. (4) The pulverized coal used for hydrogenation has a high volatile content and fine particles with an average particle size in the micrometer range. It is also a flammable material. If the flow velocity in the pipeline is high during the mixing and transportation of fine pulverized coal with high-pressure hydrogen, it will cause static sparks, which can easily cause an explosion, and there is also a safety hazard.

[0004] Therefore, there is an urgent need to find a new hydrogenation gasification method to solve the above-mentioned problems in using high-pressure hydrogen to transport pulverized coal. Summary of the Invention

[0005] To address the aforementioned technical problems, this disclosure provides a hydrogenation gasification method. In this method, an inert gas is used instead of high-pressure hydrogen for coal powder transportation, which avoids hydrogen embrittlement in the transport pipeline and prevents problems such as spontaneous combustion of coal powder and explosions caused by electrostatic sparks.

[0006] In a first aspect, this disclosure provides a method for hydrogenation gasification, the method comprising:

[0007] (1) Use an inert gas with a certain pressure to transport pulverized coal to the gasification reaction unit;

[0008] (2) In the gasification reaction device, the pulverized coal raw material undergoes a hydrogenation gasification reaction with hydrogen.

[0009] In this disclosure, high pressure is generated using an inert gas instead of high-pressure hydrogen. Since the molecules or atoms of the inert gas are relatively large, it is difficult for the inert gas to penetrate the metal, thus avoiding hydrogen embrittlement. Furthermore, because hydrogen and pulverized coal are transported to the gasification reactor via separate pipelines, introducing an inert gas to transport the pulverized coal can also, to some extent, prevent spontaneous combustion of the pulverized coal or explosions caused by electrostatic sparks.

[0010] Furthermore, using inert gas instead of high-pressure hydrogen to transport pulverized coal enables the pulverized coal to achieve a stable flow rate within a shorter pipeline, thereby solving problems such as long pipelines and complex design that exist when using high-pressure hydrogen to transport pulverized coal.

[0011] Since the pressure of the inert gas determines the conveying rate and conveying volume of pulverized coal, as a preferred technical solution of this disclosure, the pressure is 7.5-8 MPa, for example 7.6 MPa, 7.7 MPa, or 7.8 MPa.

[0012] During the process of transporting pulverized coal to the gasification reactor via pipeline, the pressure needs to be controlled at around 7.5-8 MPa to ensure the amount of pulverized coal delivered to the gasification reactor. If the pressure is too low, the delivery volume may be too small, which will reduce the amount of products generated by the reaction. If the pressure is too high, it will not only put a heavy burden on the pipeline, but also cause the amount of pulverized coal delivered to the gasification reactor to be too large, which will lead to incomplete coal reaction and waste of raw materials.

[0013] As a preferred embodiment of this disclosure, the inert gas is selected from any one or a combination of at least two of nitrogen, carbon dioxide, or argon, preferably nitrogen and / or carbon dioxide.

[0014] As a preferred technical solution of this disclosure, the pulverized coal raw material is pulverized coal containing methanol.

[0015] Using methanol-containing coal powder as a reaction raw material has two advantages. First, due to the principle of "like dissolves like," methanol has a certain dissolving effect on the organic matter in the coal powder. This dissolution can remove some organic matter blocking the coal structure. After the organic matter is dissolved, micropores will form in the original locations of the organic matter in the coal structure, which will play a role in opening up, expanding, and increasing the porosity of the coal powder, thus promoting the coal hydrogasification reaction. Second, methanol can be considered a hydrogen generator, which can decompose to produce active hydrogen. Active hydrogen can further promote the hydrogasification reaction and optimize the product distribution. The thermal decomposition reaction of methanol at the pressure and temperature corresponding to the hydrogasification reaction is as follows:

[0016] Main reaction:

[0017] CH3OH→CO+4H·-90.7KJ / mol

[0018] Side reactions:

[0019] 2CH3OH→CO2+CH4+4H·

[0020] 2CH3OH + 3O2 → 2CO2 + 4H2O

[0021] As shown in the above reactions, the thermal decomposition of methanol mainly produces carbon monoxide and active hydrogen (H·), as well as small or trace amounts of carbon dioxide, methane, and water vapor. Furthermore, since the main reaction is endothermic, the higher the reaction temperature, the more complete the methanol decomposition, the more stable the products, and the fewer side reactions occur. Compared to directly using H2 in the reaction, the active hydrogen (H·) formed after the -OH bond breaks during the methanol decomposition process has higher reactivity than stable H2, making it easier to undergo hydrogasification with coal. Therefore, it reduces the difficulty of coal powder contacting hydrogen and undergoing hydrogasification, increases the degree of hydrogasification reaction, and is beneficial for improving the overall carbon conversion rate of the hydrogasification reaction and promoting the lightness of the product oil, thereby improving the oil quality. Furthermore, the products of methanol decomposition are the same as those of the hydrogasification reaction, and no impurity gases are added to the products, so the post-hydrogasification processing is not affected. Therefore, in this disclosure, in order to avoid the presence of too many impurities affecting the hydrogasification reaction and product separation, the purity of liquid methanol is preferably 95%-98%, such as 95.5%, 96%, 96.5%, 97%, 97.5%, etc.

[0022] Furthermore, since 1 mol of methanol produces 4 mol of active hydrogen (H·), and the active hydrogen can react with coal powder to generate products, this disclosure reduces the amount of raw material hydrogen required for the hydrogasification process by using methanol coal powder as raw material. Meanwhile, considering that hydrogasification is usually a reaction with excess hydrogen, the reaction process only consumes a portion of the raw material hydrogen, and the remaining hydrogen can be recycled back into the reactor to maintain the hydrogen pressure in the reactor. In addition, to ensure that the methanol and coal powder are mixed in a solid state for easy transportation, and to prevent the addition of too much methanol to the coal powder from causing a significant drop in reactor temperature after the cold methanol-coal powder enters the hydrogasification reactor, thus affecting a series of reactions, as a preferred technical solution of this disclosure, the preferred amount of methanol added to the coal powder is mainly based on the methanol providing sufficient hydrogen consumption. That is, in the coal powder containing methanol, the mass ratio of methanol to coal powder is 0.03-0.05:1, for example 0.04:1, so as to provide sufficient active hydrogen for the hydrogasification reaction, obtain better product distribution, and make the role of the raw material hydrogen mainly as circulating hydrogen to maintain sufficient hydrogen pressure in the hydrogasification system, thereby reducing the demand for raw material hydrogen in the hydrogasification process.

[0023] In the methanol-coal powder provided in this disclosure, the amount of methanol is preferably within the range specified in this disclosure. If the amount of methanol added is too low, the improvement in efficiency of the hydrogenation gasification reaction will not be significant. However, if the amount of methanol added is too high, on the one hand, it will increase the cost of using methanol, and on the other hand, it will also lead to the presence of more C and O impurities in the product, which will increase the cost of product impurity removal. Furthermore, if the amount of methanol introduced is too high, after entering the reaction device, sufficient hydrogen needs to be provided to maintain the reaction pressure, that is, it will actually increase the amount of hydrogen used.

[0024] Considering the dissolving effect of methanol on pulverized coal and the time cost of industrial production, as a preferred technical solution of this disclosure, the pulverized coal containing methanol is mixed with methanol by spraying, preferably by spraying methanol into the pulverized coal in a mist-like manner. The spray nozzles are located at the top of the methanol-pulverized coal tank, preferably distributed in a spiderweb pattern from the outside in. Simultaneously, mixing can be achieved by mechanically agitating the pulverized coal within the tank to ensure that the methanol and pulverized coal are mixed as thoroughly as possible. The preferred mechanical agitation speed is 200-350 rpm, such as 220 rpm, 250 rpm, 280 rpm, 300 rpm, 320 rpm, etc., to ensure uniform mixing of methanol and pulverized coal, while preventing methanol and pulverized coal from splashing to the top of the tank during agitation to avoid clogging the methanol spray nozzles.

[0025] Regarding the flow rate of methanol spraying, the methanol flow rate per unit time during spraying is calculated and controlled based on the methanol / coal mass ratio of 0.03-0.05:1 and the preparation time cycle of methanol-coal powder.

[0026] As a preferred embodiment of this disclosure, the mixing temperature of methanol and pulverized coal is 20-80℃, such as 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, etc.; the mixing time is 1-2 hours, such as 1.1 hours, 1.2 hours, 1.4 hours, 1.5 hours, 1.6 hours, 1.8 hours, etc. The mixing temperature range of 20-80℃ in this disclosure ensures thorough mixing of methanol and pulverized coal and allows methanol to dissolve some organic matter in the pulverized coal to a certain extent, enhancing the promoting effect of methanol on the hydrogenation gasification reaction. Simultaneously, a lower preparation temperature ensures the safety of the methanol-pulverized coal preparation process.

[0027] This disclosure utilizes inert gas to transport methanol-coal powder, which is transported under high pressure in a solid state. Solid transport facilitates the control of the coal powder transport volume and expands the range of transport volume. In practical applications, the expanded range of transport volume means that the number of nozzles required for the hydrogenation gasification reactor can be freely adjusted, or even reduced, thereby reducing the design difficulty of the reactor.

[0028] As a preferred embodiment of this disclosure, the conveying is carried out by a tubular screw feeder.

[0029] Methanol-coal powder, prepared by combining methanol and coal powder, is fed into a reactor using a screw feeder for hydrogasification. As mentioned earlier in industrial production, the coal powder conveying capacity of a single screw feeder ranges from 0.1 tons / hour to 900 tons / hour. To match the different settings of the hydrogen and oxygen injection nozzles, the preferred coal powder conveying capacity of a single screw feeder is 5 tons / hour to 300 tons / hour. The overall coal powder conveying capacity is determined by the designed processing capacity of the hydrogasification reactor and the number of coal powder screw feeders installed.

[0030] For pressurized operations, high-pressure tubular screw feeders are generally selected. The conveying pipeline of this type of feeder is generally less than 10 meters to achieve stable conveying. The conveying distance required is very short, which simplifies the pipeline design. Moreover, the short pipeline distance can be used entirely with straight pipes, greatly reducing the use of bends and solving the problem of needing long pipelines and many bends to maintain a stable flow rate when conveying high-pressure hydrogen pulverized coal.

[0031] Furthermore, current high-pressure hydrogen-coal powder conveying technologies utilize pressure differential and pipe diameter to regulate the conveying rate, with each pipeline typically having a conveying rate range of 0.2 tons / hour to 4.2 tons / hour. This limited range necessitates an increase in the number of coal powder nozzles in industrial installations, complicating pressure vessel design. In contrast, the high-pressure screw feeder disclosed in this invention has a conveying rate related to screw shaft speed, screw pitch, screw diameter, filling coefficient, and the characteristics of the conveyed material. By adjusting the screw shaft speed, the methanol-coal powder conveying rate can be effectively controlled. Adjusting the screw shaft speed to a range of 20-150 rpm allows for a coal powder conveying rate range of 0.1 tons / hour to 900 tons / hour, significantly reducing the number of coal powder nozzles required in industrial installations and lowering the design complexity of the hydrogasification reaction pressure vessel.

[0032] As a preferred technical solution of this disclosure, the conveying capacity of the pulverized coal is 0.1-900 tons / hour, such as 1 ton / hour, 5 tons / hour, 10 tons / hour, 20 tons / hour, 50 tons / hour, 100 tons / hour, 150 tons / hour, 200 tons / hour, 250 tons / hour, 300 tons / hour, 350 tons / hour, 400 tons / hour, 500 tons / hour, 600 tons / hour, 700 tons / hour, 800 tons / hour, etc., preferably 5-300 tons / hour.

[0033] As a preferred embodiment of this disclosure, in the hydrogenation gasification reaction, the mass ratio of hydrogen to pulverized coal is 0.05-0.6:1, for example, 0.1:1, 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, 0.55:1, etc., preferably 0.2-0.4:1.

[0034] In this disclosure, since the added methanol can generate active hydrogen through thermal decomposition, the amount of raw material hydrogen used can be reduced when methanol-coal powder is used, thereby reducing production costs to a certain extent.

[0035] As a preferred technical solution of this disclosure, the D of the pulverized coal 90 ≤75μm, such as 70μm, 65μm, 50μm, etc., and moisture content ≤5%, such as 4.5%, 4%, 3%, 2%, etc.

[0036] The pulverized coal used in this disclosure has a small particle size, which could pose certain risks if transported using high-pressure hydrogen. This disclosure uses an inert gas instead of high-pressure hydrogen, which satisfies the transportation requirements while reducing the risks of hydrogen embrittlement and spontaneous combustion. Furthermore, using methanol-coal powder instead of pulverized coal as the feedstock reduces the amount of hydrogen required for the hydrogasification process. Transporting it in solid form increases the transport capacity, reduces the number of nozzles, and simplifies the design of the hydrogasification reactor.

[0037] In this disclosure, the hydrogenation gasification reactor has an independent integrated hydrogen and oxygenation nozzle and a pulverized coal nozzle, which are conventional hydrogenation gasification reactors in the current field, and this disclosure does not impose any further limitations.

[0038] In the hydrogasification reactor, the pulverized coal pipe (nozzle) is preferably located at the top of the reactor and symmetrically arranged at the top to ensure uniform distribution of pulverized coal within the reactor and sufficient contact with hot hydrogen for reaction. In the hydrogen-oxygenation nozzle, the hydrogen pipe is arranged adjacent to the oxygen pipe or in an epoxy-coated configuration with an oxygen pipe nested inside the hydrogen pipe, ensuring that a small amount of oxygen only burns with hydrogen and does not participate in the hydrogasification reaction of coal. Here, the hydrogen-oxygenation nozzle is preferably located at the top of the reactor and symmetrically arranged below the pulverized coal pipe (nozzle) to ensure uniform gas distribution within the reactor and sufficient contact between the falling pulverized coal and hot hydrogen. When the hydrogen and oxygen pipes are arranged adjacent to each other, the vertical distance between the pulverized coal pipe (nozzle) and the hydrogen pipe is less than the vertical distance between the pulverized coal pipe (nozzle) and the oxygen pipe to avoid the reaction of coal and oxygen to produce carbon oxides, thus reducing the yield of effective product gas.

[0039] The technical solution provided in this disclosure has the following advantages compared with the prior art:

[0040] (1) In the hydrogenation gasification method provided in this disclosure, inert gas is used instead of high-pressure hydrogen for coal powder transportation, which can avoid "hydrogen embrittlement" in the transportation pipeline and avoid problems such as spontaneous combustion of coal powder and explosion caused by electrostatic sparks.

[0041] (2) Using methanol-coal powder as raw material can save some hydrogen usage and promote the coal hydrogenation gasification reaction, thereby increasing the product yield.

[0042] (3) Methanol pulverized coal is transported in solid form, which facilitates the control of the amount of pulverized coal transported and expands the range of transport volume. It can reduce the number of reactor nozzles and reduce the design difficulty of hydrogenation gasification reaction device. Attached Figure Description

[0043] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0044] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0045] Figure 1 This is a photograph of a delivery pipeline that did not exhibit "hydrogen embrittlement" during the performance testing of this publication.

[0046] Figure 2 This is a photograph showing "hydrogen embrittlement" in the pipeline during performance testing as disclosed in this publication. Detailed Implementation

[0047] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0048] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0049] Example 1

[0050] This embodiment provides a method for hydrogenation.

[0051] (1) 140t of qualified coal powder at room temperature (particle size D) 90<75μm, moisture content about 2%) are filled into the methanol-coal powder tank. The coal powder is sprayed with methanol at a methanol:coal powder mass ratio of 0.032:1. At the same time, the mechanical agitator in the tank is started. The coal powder is stirred at 250 rpm at room temperature. After stirring for 1.5 hours, a methanol-coal powder mixture is obtained.

[0052] (2) The methanol pulverized coal tank is pressurized with nitrogen to about 8 MPa and methanol pulverized coal is fed into the hydrogasification reactor at a flow rate of 67.1 tons / hour (the coal powder conveying capacity is 65 tons / hour) using a screw feeder.

[0053] (3) Hydrogen gas is supplied to the hydrogenation gasification reactor through a hydrogen oxygenation nozzle at a hydrogen-to-coal ratio of 0.245:1, where it undergoes a gasification reaction with methanol-coal powder. The oxygen flow rate is 7500 Nm³. 3 / h, the hydrogen flow rate is 190,000 Nm 3 / h, the gasification reaction temperature is 850℃, and the pressure is 7.0MPa.

[0054] Example 2

[0055] This embodiment provides a method for hydrogenation.

[0056] (1) 140t of qualified coal powder at room temperature (particle size D) 90 <70μm, moisture content about 4%) are filled into the methanol-coal powder tank. The coal powder is sprayed with methanol at a methanol:coal powder mass ratio of 0.05:1. At the same time, the mechanical agitator in the tank is started. The coal powder is stirred at 350 rpm at 40℃. After stirring for 1 hour, a mixture of methanol and coal powder is obtained.

[0057] (2) The methanol pulverized coal tank is pressurized with nitrogen to about 7.5 MPa and methanol pulverized coal is fed into the hydrogasification reactor at a flow rate of 105 tons / hour (the coal powder conveying capacity is 100 tons / hour) using a screw feeder.

[0058] (3) Hydrogen gas is supplied to the hydrogenation gasification reactor through a hydrogen oxygenation nozzle at a hydrogen-to-coal ratio of 0.40:1, where it undergoes a gasification reaction with methanol-coal powder. The oxygen flow rate is 16000 Nm³. 3 / h, the hydrogen flow rate is 462000 Nm 3 / h, the gasification reaction temperature is 850℃, and the pressure is 7.0MPa.

[0059] Example 3

[0060] This embodiment provides a method for hydrogenation.

[0061] (1) 140t of qualified coal powder at room temperature (particle size D) 90<60μm, moisture content about 3%) are filled into the methanol-coal powder tank. The coal powder is sprayed with methanol at a methanol:coal powder mass ratio of 0.04:1. At the same time, the mechanical agitator in the tank is started and the coal powder is stirred at a speed of 300 rpm. After stirring for 1.2 hours, a methanol-coal powder mixture is obtained.

[0062] (2) The methanol pulverized coal tank is pressurized with nitrogen to about 7.8 MPa and methanol pulverized coal is fed into the hydrogasification reactor at a flow rate of 208 tons / hour (the coal powder conveying capacity is 200 tons / hour) using a screw feeder.

[0063] (3) Hydrogen gas is supplied to the hydrogenation gasification reactor through a hydrogen oxygenation nozzle at a hydrogen-to-coal ratio of 0.20:1, where it undergoes a gasification reaction with methanol-coal powder. The oxygen flow rate is 17000 Nm³. 3 / h, the hydrogen flow rate is 469000 Nm 3 / h, the gasification reaction temperature is 850℃, and the pressure is 7.0MPa.

[0064] Comparative Example 1

[0065] This comparative example provides a method for hydrogenation.

[0066] (1) 140t of qualified coal powder at room temperature (particle size 90% < 75μm, moisture content about 2%) is loaded into the coal powder tank and pressurized with hydrogen to about 7.5-8MPa; coal powder is transported to the hydrogenation gasification reactor at a rate of 65 tons / hour through 16 coal powder conveying pipelines.

[0067] (2) Based on a hydrogen / coal mass ratio of 0.252, the oxygen flow rate introduced into the hydrogen oxygenation nozzle of the hydrogenation gasification reactor is 7500 Nm³. 3 / h, hydrogen flow rate 195000 Nm 3 / h, hydrogen and oxygen are burned to preheat the remaining hydrogen and promote the hydrogenation gasification reaction between the hydrogen and the pulverized coal entering the reactor. The gasification reaction temperature is 850℃ and the pressure is 7.0MPa.

[0068] Comparative Example 2

[0069] This embodiment provides a method for hydrogenation.

[0070] (1) 140t of qualified coal powder at room temperature (particle size D) 90 <75μm, moisture content about 2%) are filled into the pulverized coal tank, pressurized with nitrogen to about 8MPa, and then fed into the hydrogasification reactor by a screw feeder at a pulverized coal flow rate of 65 tons / hour.

[0071] (2) Hydrogen gas is supplied to the hydrogenation gasification reactor through a hydrogen oxygenation nozzle at a hydrogen-to-coal ratio of 0.250:1, where it undergoes a gasification reaction with methanol-coal powder. The oxygen flow rate is 7500 Nm³.3 / h, the hydrogen flow rate is 193000 Nm 3 / h, the gasification reaction temperature is 850℃, and the pressure is 7.0MPa.

[0072] Comparative Example 3

[0073] This comparative example provides a method for hydrogenation.

[0074] (1) 140t of qualified coal powder at room temperature (particle size D) 90 <75μm, moisture content about 2%) are filled into the methanol-coal powder tank. The coal powder is sprayed with methanol at a methanol:coal powder mass ratio of 0.010:1. At the same time, the mechanical agitator in the tank is started and the coal powder is stirred at a speed of 250 rpm. After stirring for 1.5 hours, a methanol-coal powder mixture is obtained.

[0075] (2) The methanol pulverized coal tank is pressurized with nitrogen to about 8 MPa and methanol pulverized coal is fed into the hydrogasification reactor at a flow rate of 65.7 tons / hour (65 tons / hour by mass of pulverized coal) using a screw feeder.

[0076] (3) Hydrogen gas is supplied to the hydrogenation gasification reactor through a hydrogen oxygenation nozzle at a hydrogen-to-coal ratio of 0.248:1, where it undergoes a gasification reaction with methanol-coal powder. The oxygen flow rate is 7500 Nm³. 3 / h, the hydrogen flow rate is 192000 Nm 3 / h, the gasification reaction temperature is 850℃, and the pressure is 7.0MPa.

[0077] Comparative Example 4

[0078] This comparative example provides a method for hydrogenation.

[0079] (1) 140t of qualified coal powder at room temperature (particle size D) 90 <75μm, moisture content about 2%) are filled into the methanol-coal powder tank. The coal powder is sprayed with methanol at a methanol:coal powder mass ratio of 0.070:1. At the same time, the mechanical agitator in the tank is started and the coal powder is stirred at a speed of 250 rpm. After stirring for 1.5 hours, a methanol-coal powder mixture is obtained.

[0080] (2) The methanol pulverized coal tank is pressurized with nitrogen to about 8 MPa and methanol pulverized coal is fed into the hydrogasification reactor at a flow rate of 69.8 tons / hour (65 tons / hour by mass of pulverized coal) using a screw feeder.

[0081] (3) Hydrogen gas is supplied to the hydrogenation gasification reactor through a hydrogen oxygenation nozzle at a hydrogen-to-coal ratio of 0.255:1, where it undergoes a gasification reaction with methanol-coal powder. The oxygen flow rate is 9000 Nm³. 3 / h, the hydrogen flow rate is 200,000 Nm3 / h, the gasification reaction temperature is 850℃, and the pressure is 7.0MPa.

[0082] Performance testing

[0083] (1) Safety performance comparison: After conveying pulverized coal using the methods for conveying hydrogen provided in Examples 1-3 or Comparative Example 1 for a period of time, the occurrence of "hydrogen embrittlement" in the pipeline was observed. The results are shown in Table 1:

[0084] Table 1

[0085]

[0086] As can be seen from the examples and safety comparisons, the hydrogenation method provided in this disclosure can still avoid the phenomenon of "hydrogen embrittlement" and reduce the risk of spontaneous combustion after long-term operation.

[0087] (2) Comparison of hydrogen consumption: The hydrogen consumption of the hydrogenation methods provided in Example 1 and Comparative Examples 1-4 is compared, and the results are shown in Table 2:

[0088] Table 2

[0089] Hydrogenation method <![CDATA[Hydrogen consumption, Nm 3 / h]]> Example 1 190000 Comparative Example 1 195000 Comparative Example 2 193000 Comparative Example 3 192000 Comparative Example 4 200000

[0090] As shown in Table 2, the hydrogenation method provided in this disclosure can reduce the amount of hydrogen used. Specifically:

[0091] Comparative Example 1 represents the current existing process. On one hand, the transportation of solid pulverized coal requires pressurized hydrogen, which increases the demand for hydrogen. On the other hand, since the raw material used in Comparative Example 1 is qualified pulverized coal at room temperature, which does not contain methanol, a certain amount of hydrogen needs to be added to meet the reaction pressure requirements in the hydrogasification reaction. Therefore, a comparison between Example 1 and Comparative Example 1 shows that, compared with the current existing process (Comparative Example 1), under the same pulverized coal processing capacity, the hydrogasification method provided in this disclosure can reduce hydrogen consumption by 5000 Nm³. 3 Based on an annual operating time of 8,000 hours, this can reduce hydrogen consumption by 40 million cubic meters per hour.

[0092] Meanwhile, in Comparative Example 1, high-pressure hydrogen is used as the carrier gas for transporting pulverized coal, which places high demands on the pressure differential and pipelines. To achieve stable transport, a pressure differential of 0.2 MPa must be maintained between the pulverized coal tank and the hydrogasification reactor. The maximum transport capacity is approximately 4.2 tons / hour. For a total pulverized coal transport capacity of 65 tons / hour, a total of 16 pulverized coal transport pipelines are needed to supply the hydrogasification reactor. Therefore, a comparison between Example 1 and Comparative Example 1 shows that this disclosure, by using an inert gas to generate high pressure instead of high-pressure hydrogen, can reduce the use of transport pipelines and lower the requirements for pulverized coal transport.

[0093] Comparative Example 2 uses qualified coal powder at room temperature. To meet the reaction pressure requirements in the hydrogasification reaction, a sufficient amount of hydrogen is required. Example 1 uses coal powder containing methanol (methanol-coal powder). Since methanol provides a certain reaction pressure and can also replace hydrogen in the gasification reaction, a comparison between Comparative Example 2 and Example 1 shows that using methanol-coal powder reduces hydrogen consumption compared to using raw coal powder. With the same coal powder processing capacity, using methanol-coal powder reduces hydrogen consumption by 3000 Nm³. 3 Based on an annual operating time of 8,000 hours, this can reduce hydrogen consumption by 24 million cubic meters per hour.

[0094] In Comparative Example 3, the amount of methanol introduced was relatively small (methanol:coal powder mass ratio was 0.010:1). A comparison of the hydrogen usage in Comparative Example 3 and Example 1 shows that while a lower methanol content can reduce hydrogen usage to some extent, the reduction is minimal. In Comparative Example 4, the amount of methanol introduced was relatively large (methanol:coal powder mass ratio was 0.070:1). A comparison of the hydrogen usage in Comparative Example 4 and Example 1 shows that if the methanol usage is too high, the rapid decomposition of methanol upon entering the reaction apparatus will cause pressure instability, necessitating the supply of sufficient hydrogen to maintain the reaction pressure, thus increasing hydrogen usage. Therefore, a comparison of Example 1 and Comparative Examples 3-4 indicates that in coal powder containing methanol, a methanol:coal powder mass ratio of 0.03-0.05:1 provides sufficient active hydrogen for the hydrogenation reaction while avoiding an increase in hydrogen usage and minimizing hydrogen consumption.

[0095] (3) Reaction efficiency: The yield and carbon conversion of the final products obtained in Examples 1-3 and Comparative Examples 1-4 are compared, and the results are shown in Table 3:

[0096] Table 3

[0097]

[0098] As can be seen from the examples and performance tests, the hydrogasification method provided in this disclosure can improve the carbon conversion rate. Specifically, compared with the existing process (Comparative Example 1), the carbon conversion rate of the method provided in Example 1 is increased by about 4%, the methane yield is increased by about 10%, and the light aromatics yield is increased by about 17%.

[0099] Comparative Example 1 does not use inert gas for transportation, nor does it use coal powder containing methanol, while Comparative Example 2 uses inert gas for transportation but does not use coal powder containing methanol. Therefore, by comparing Comparative Example 2 and Comparative Example 1, it can be seen that when using the transportation method in the hydrogenation gasification reaction method provided in this disclosure, even if methanol coal powder is not used, it will not have any adverse effects on the reaction.

[0100] The raw material used in Comparative Example 2 was qualified coal powder at room temperature, while the raw material used in Example 1 was coal powder containing methanol. The comparison between Comparative Example 2 and Example 1 shows that using coal powder containing methanol as a reaction raw material can improve the carbon conversion rate of coal powder and increase the product yield.

[0101] In Comparative Example 3, the amount of methanol introduced was relatively small (methanol:coal powder mass ratio was 0.010:1). A comparison between Comparative Example 3 and Example 1 shows that a low methanol introduction does not significantly improve the carbon conversion rate of the coal powder. In Comparative Example 4, the amount of methanol introduced was relatively large (methanol:coal powder mass ratio was 0.070:1). A comparison between Comparative Example 4 and Example 1 shows that an excessive methanol introduction will not further improve the carbon conversion rate of the coal powder; instead, it will lead to more impurities in the product (the decrease in carbon conversion rate indicates that other side reactions of the coal powder have occurred, generating impurities). Therefore, a comparison between Example 1 and Comparative Examples 3-4 shows that a methanol:coal powder ratio in the range of 0.03-0.05:1 can improve the yield of the hydrogasification reaction, avoid the generation of excessive C and O impurities, and reduce the amount of hydrogen used.

[0102] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0103] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for hydrogenation gasification, characterized in that, The method includes: (1) The pulverized coal raw material is transported to the gasification reaction unit using an inert gas with a certain pressure; (2) In the gasification reaction device, the pulverized coal raw material undergoes a hydrogenation gasification reaction with hydrogen; The inert gas is selected from at least one of the following: nitrogen, carbon dioxide, and argon; The coal powder raw material is coal powder containing methanol; In the methanol-containing coal powder, the mass ratio of methanol to coal powder is 0.03-0.05:1; The methanol-containing coal powder is produced by mixing methanol with coal powder through spraying.

2. The method according to claim 1, characterized in that, The pressure is 7.5-8 MPa.

3. The method according to claim 1, characterized in that, The inert gas is nitrogen and / or carbon dioxide.

4. The method according to claim 1, characterized in that, The methanol-containing coal powder is prepared by mixing methanol with coal powder in a mist spray manner.

5. The method according to claim 4, characterized in that, The mixing temperature is 20-80℃.

6. The method according to claim 4 or 5, characterized in that, The mixing time is 1-2 hours.

7. The method according to claim 1, characterized in that, The conveying is carried out by a tubular screw feeder.

8. The method according to claim 7, characterized in that, The conveying capacity of the pulverized coal is 0.1-900 tons / hour.

9. The method according to claim 8, characterized in that, The conveying capacity of the pulverized coal is 5-300 tons / hour.

10. The method according to claim 1, characterized in that, In the hydrogenation gasification reaction, the mass ratio of hydrogen to pulverized coal is 0.05-0.6:

1.

11. The method according to claim 10, characterized in that, The mass ratio of hydrogen to pulverized coal is 0.2-0.4:

1.

12. The method according to claim 1, characterized in that, The coal powder D 90 ≤75 μm, moisture content ≤5%.

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