System for producing carbon nanotubes and hydrogen by using carbonaceous material
By integrating a gasifier, a shift converter, and a tail gas treatment unit into the chemical process, and adjusting the H2 to CO ratio, carbon nanotube raw materials are generated and hydrogen is recovered. This solves the problems of CO2 emissions and high costs in traditional coal chemical industry, and realizes low-cost and environmentally friendly carbon nanotube production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-27
- Publication Date
- 2026-03-06
AI Technical Summary
In traditional chemical processes, the production of methanol, methane, olefins and other compounds from coal emits a large amount of CO2 and loses carbon elements, resulting in poor environmental performance. Furthermore, the cost of existing carbon nanotube raw materials is high.
A system for producing carbon nanotubes and hydrogen using carbon-containing materials includes a syngas unit, a syngas conversion unit, carbon nanotube production equipment, and a tail gas treatment unit. The system adjusts the H2 to CO ratio through a gasifier and a converter to generate carbon nanotube raw materials and recovers hydrogen from the tail gas, thereby reducing CO2 emissions and raw material consumption.
It reduces the raw material cost of carbon nanotubes, reduces CO2 emissions, improves the environmental friendliness of the production process, and reduces equipment investment and transportation costs.
Smart Images
Figure CN223969940U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of carbon-containing material utilization equipment, specifically relating to a system for producing carbon nanotubes and hydrogen using carbon-containing materials. Background Technology
[0002] Carbon-containing materials include coal, petroleum coke, semi-coke, and biomass. These contain large amounts of carbon, fixing most of the carbon in nature in carbon form, making them abundant energy sources. In the chemical industry, the carbon in these materials can be used to produce compounds such as methanol, methane, and olefins, which are crucial bulk chemical raw materials. For example, in a typical coal-to-methanol / methane process, coal gasification yields crude coal gas. The ratio of hydrogen to carbon monoxide in this crude coal gas is low, requiring the addition of steam for a syngas shift process. The carbon monoxide reacts with the steam to produce carbon dioxide and hydrogen, increasing the hydrogen content while simultaneously releasing carbon dioxide. Once the hydrogen-to-carbon monoxide ratio is properly adjusted, it can be used to produce compounds such as methanol, dimethyl ether, methane, ethylene, propylene, and aromatics.
[0003] As can be seen from the above reaction process, adjusting the H2 to CO ratio involves consuming an equimolar amount of CO and producing an equimolar amount of H2 and CO2, which is equivalent to converting the carbon in the coal into CO2 and consuming it. CO2 is a greenhouse gas, and internationally, strict restrictions have been implemented on large-scale CO2 emissions. Currently, producing one ton of methanol from coal emits more than three tons of carbon dioxide; producing one ton of olefins from coal emits more than six tons of carbon dioxide. Such high carbon emissions are very environmentally unfriendly. Utility Model Content
[0004] The technical problem this invention aims to solve is that, according to traditional chemical processes, the crude coal gas obtained from coal gasification, especially coal, needs to be reacted with water vapor. After adjusting the ratio of H2 to CO, compounds such as methanol, methane, and olefins are then produced. This process emits a large amount of CO2 and loses carbon elements, resulting in poor environmental performance. Currently, the raw materials for producing carbon nanotubes are polymer-grade pure ethylene or pure propylene, which have extremely high raw material costs.
[0005] This utility model proposes a system for producing carbon nanotubes and hydrogen using carbon-containing materials, including a syngas unit, a syngas conversion unit, a carbon nanotube production equipment and a tail gas treatment unit connected in sequence. The syngas unit includes a gasifier and a converter connected in sequence. The carbon-containing material is fed into the gasifier and gasified to obtain crude syngas. The crude syngas is fed into the converter to adjust the ratio of H2 to CO to obtain syngas.
[0006] Syngas is converted into carbon-containing organic compounds in the syngas conversion unit, which serve as raw materials for the production of carbon nanotubes. The carbon nanotube production equipment contains a catalyst and is connected to a tail gas treatment unit via a tail gas pipe. The tail gas treatment unit includes a dust removal device, a cooling device, and a gas separation device connected in sequence. After dust removal and cooling, the tail gas generated by the carbon nanotube production equipment is fed into the gas separation device to separate hydrogen. The hydrogen outlet of the gas separation device is connected to the front end of the syngas unit and / or the syngas conversion unit via a hydrogen pipeline. The separated hydrogen is fed into the front end of the syngas unit and / or the syngas conversion unit via a hydrogen pipeline to adjust the ratio of H2 to CO.
[0007] Optionally, the system further includes a pretreatment device for pretreating carbonaceous materials. The pretreatment device is selected from one or more of crushing equipment, pulverizing equipment, drying equipment, and granulation equipment.
[0008] Optionally, the carbon-containing material is selected from one of coal, petroleum coke, semi-coke, and biomass.
[0009] Optionally, the gasifier is provided with a feed inlet at the top, a slag discharge outlet at the bottom, and an exhaust outlet on the side, which are used to discharge the ash and slag after the gasification of carbonaceous materials and to discharge the crude syngas, respectively.
[0010] The exhaust port of the gasifier is connected to the inlet of the converter via a gas pipe. The hydrogen pipeline is connected to this gas pipe, and the separated hydrogen and crude syngas are fed into the converter.
[0011] Optionally, the top of the converter is provided with an air inlet for inputting a mixture of crude syngas and hydrogen, and the bottom of the converter is provided with an exhaust port for discharging syngas.
[0012] A purification device is installed between the converter and the syngas conversion unit. The exhaust port 2 is connected to the inlet of the purification device through a pipeline to remove impurities from the syngas. The outlet of the purification device is connected to the syngas conversion unit through a pipeline.
[0013] Optionally, the syngas conversion unit includes a syngas reactor in which syngas is converted into carbon-containing organic compounds.
[0014] The carbon-containing organic compound is one of methane, ethylene, propylene, or aromatic hydrocarbons. The carbon-containing organic compound is directly input into the carbon nanotube production equipment to produce carbon nanotubes.
[0015] Optionally, the syngas conversion unit includes a syngas reactor in which syngas is converted into carbon-containing organic compounds; the carbon-containing organic compounds are either methanol or dimethyl ether. Between the syngas conversion unit and the carbon nanotube reactor, there is also a catalytic decomposition reactor, a second cooling device, a water washing device, and a second drying device connected in sequence. The catalytic decomposition reactor is equipped with a heating device and contains a molecular sieve catalyst. The carbon-containing organic compounds are input into the catalytic decomposition reactor and decomposed into a mixed gas containing hydrocarbons under the action of the molecular sieve catalyst.
[0016] Optionally, the catalytic decomposition reactor is provided with an exhaust port four at the top, which is connected to a cooling device two. The cooling device two, the water washing device, and the drying device two are connected in series. The exhaust port at the top of the upstream device is connected to the inlet of the downstream device, which cools, washes, and dries the mixed gas containing hydrocarbons, respectively, to remove carbon dioxide, water, and a small amount of oxygen-containing organic impurities, thus avoiding poisoning the catalyst in the carbon nanotube production equipment. The exhaust port of the drying device is connected to the inlet of the carbon nanotube reactor.
[0017] The system for producing carbon nanotubes and hydrogen using carbon-containing materials proposed in this invention has the following beneficial effects:
[0018] (1) A large amount of hydrogen produced by the carbon nanotube production equipment is returned to the conversion furnace through the hydrogen pipeline, that is, returned to the synthesis gas production process, to adjust the H2 / CO ratio. This avoids using the reaction of CO with water vapor to generate H2 and CO2 to adjust the H2 / CO ratio, reduces the loss of C elements, reduces the consumption of carbon-containing materials, reduces CO2 emissions, and improves the environmental friendliness of the production process.
[0019] At the same time, reduce facilities that allow CO to react with water vapor, thus reducing equipment investment;
[0020] (2) Using carbon-containing materials as raw materials, compounds such as methanol, methane, and olefins can be prepared at low cost, and then carbon nanotubes can be further produced, which greatly reduces the raw material cost of carbon nanotubes. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of a system for producing carbon nanotubes and hydrogen using carbon-containing materials.
[0022] Figure 2 This is a schematic diagram of another system that uses carbon-containing materials to produce carbon nanotubes and hydrogen.
[0023] In the attached diagram, 1-gas separation equipment, 2-gasification furnace, 3-conversion furnace, 4-exhaust port one, 5-exhaust port two, 6-exhaust port three, 7-exhaust port four, 8-hydrogen pipeline, 9-purification equipment, 10-syngas reactor, 11-catalytic decomposition reactor, 12-cooling equipment one, 13-water washing equipment, 14-drying equipment two, 15-cooling equipment two, 16-carbon nanotube production equipment, 17-dust removal equipment, 18-slag discharge port. Detailed Implementation
[0024] This embodiment proposes a system for producing carbon nanotubes and hydrogen using carbon-containing materials, such as... Figures 1-2 As shown, it includes a syngas unit, a syngas conversion unit, a carbon nanotube production device 16 and a tail gas treatment unit connected in sequence. The syngas unit includes a gasifier 2 and a converter 3 connected in sequence. Carbon-containing materials are fed into the gasifier 2 for gasification to obtain crude syngas. The crude syngas is fed into the converter 3 to adjust the ratio of H2 to CO to obtain syngas.
[0025] Syngas is converted into carbon-containing organic compounds in the syngas conversion unit, which are used as raw materials for the production of carbon nanotubes. The carbon nanotube production equipment 16 is equipped with a catalyst and is connected to the tail gas treatment unit through a tail gas pipe. The tail gas treatment unit includes a dust removal device 17, a cooling device 12, and a gas separation device 1 connected in sequence. After dust removal and cooling, the tail gas generated by the carbon nanotube production equipment 16 is fed into the gas separation device to separate hydrogen. The hydrogen outlet of the gas separation device 1 is connected to the front end of the syngas unit and / or the syngas conversion unit through a hydrogen pipeline 8. The separated hydrogen is fed into the front end of the syngas unit and / or the syngas conversion unit through a hydrogen pipeline to adjust the ratio of H2 to CO.
[0026] Optionally, the system further includes a pretreatment device for pretreating carbonaceous materials. The pretreatment device is selected from one or more of crushing equipment, pulverizing equipment, drying equipment, and granulation equipment.
[0027] Optionally, the carbon-containing substances include, but are not limited to, coal, petroleum coke, semi-coke, biomass, plastic waste, heavy oil, natural gas, naphtha, and residual oil.
[0028] Select appropriate pretreatment equipment based on the specific type of carbonaceous material. For coal, petroleum coke, or semi-coke, the pretreatment device includes a crushing device, a pulverizing device, and a drying device connected in sequence. This device is used to crush lumpy coal to a small particle size and remove most of the moisture, or to prepare a coal-water slurry for easy feeding into the gasifier for gasification.
[0029] For biomass, such as branches, leaves, sawdust, wheat straw, corn stalks, rice husks, rice seedlings, peanut vines, peanut shells, and weeds, as well as domestic waste, urban sludge, and livestock manure, the pretreatment device includes a crushing device, a pulverizing device, a drying device, and a granulation device connected in sequence. This device is used to crush the biomass to a suitable particle size. Generally, biomass contains a lot of moisture, so most of the moisture needs to be removed before it can be granulated into a suitable form and then it can continue to react and gasify.
[0030] Optionally, the gasifier 2 is provided with a feed inlet at the top, a slag discharge port 18 at the bottom, and an exhaust port 4 on the side, which are used to discharge the ash and slag after the gasification of carbonaceous materials and to discharge the crude syngas, respectively.
[0031] The exhaust port 4 of the gasifier 2 is connected to the inlet of the converter 3 via a gas pipe. The hydrogen pipeline 8 is connected to the gas pipe, and the separated hydrogen and crude syngas are input into the converter 3.
[0032] Gasifier 2 can be a conventional fixed-bed gasifier, fluidized-bed gasifier, entrained-flow gasifier, or plasma gasifier in this field. The appropriate type of gasifier can be selected based on the specific type of carbon-containing substance.
[0033] Optionally, the top of the converter 3 is provided with an air inlet for inputting a mixture of crude syngas and hydrogen, and the bottom is provided with an exhaust port 5 for discharging syngas.
[0034] A purification device 9 is installed between the converter 3 and the syngas conversion unit. The exhaust port 2 5 is connected to the inlet of the purification device 9 through a pipeline to remove impurities from the syngas, such as organic sulfides and carbon dioxide. The outlet of the purification device is connected to the syngas conversion unit through a pipeline. The purification device 9 is a conventional gas purification device in this field.
[0035] Optionally, the converter 3 may also be provided with a water inlet for spraying water into the converter through a humidifier, where carbon monoxide reacts with water vapor to produce carbon dioxide and hydrogen.
[0036] Optionally, the syngas conversion unit includes a syngas reactor 10, in which syngas is converted into carbon-containing organic compounds.
[0037] The carbon-containing organic compound is one of methane, ethylene, propylene, and aromatic hydrocarbons. The carbon-containing organic compound is directly input into the carbon nanotube production equipment 16 to produce carbon nanotubes.
[0038] Optionally, the syngas conversion unit includes a syngas reactor in which syngas is converted into carbon-containing organic compounds; the carbon-containing organic compounds are either methanol or dimethyl ether. Between the syngas conversion unit and the carbon nanotube reactor, there is also a catalytic decomposition reactor 11, a second cooling device 15, a water washing device 13, and a second drying device 14 connected in sequence. The catalytic decomposition reactor is equipped with a heating device and contains a molecular sieve catalyst. The carbon-containing organic compounds are input into the catalytic decomposition reactor and decomposed into a mixed gas containing hydrocarbons under the action of the molecular sieve catalyst.
[0039] Optionally, the top of the catalytic decomposition reactor is provided with an exhaust port 4, which is connected to a cooling device 2. The cooling device 2, the water washing device, and the drying device 2 are connected in series. The exhaust port at the top of the upstream device is connected to the inlet of the downstream device, which cools, washes, and dries the mixed gas containing hydrocarbons, respectively, to remove carbon dioxide, water, and a small amount of oxygen-containing organic impurities, thus avoiding poisoning the catalyst in the carbon nanotube production equipment. The exhaust port of the drying device is connected to the inlet of the carbon nanotube reactor.
[0040] Optionally, the syngas reactor 10 is provided with an inlet and an outlet 36, the outlet 3 being used to discharge gaseous carbon-containing organic compounds.
[0041] When the carbon-containing organic compound is one of methane, ethylene, propylene, or aromatics, exhaust port 36 is connected to the air inlet of carbon nanotube production equipment 16.
[0042] When the carbon-containing organic compound is methanol or dimethyl ether, exhaust port 36 is connected to the inlet of catalytic decomposition reactor 11.
[0043] Optionally, the carbon-containing organic compound is methanol, dimethyl ether, methane, or a low-carbon olefin. Depending on the ratio of hydrogen to carbon monoxide in the purified syngas, different chemical reactions occur within the syngas reactor 10. For example, when the H2 / CO ratio in the syngas is 2:1, methanol is produced; when the H2 / CO ratio is 3:1, methane is produced.
[0044] In one specific implementation, when the carbon-containing organic compound is methanol or dimethyl ether, the carbon-containing organic compound is discharged from exhaust port 6 to catalytic decomposition reactor 11. Under the action of 600-800K and a catalyst, the methanol or dimethyl ether decomposes to obtain a mixed gas containing hydrocarbons. This mixed gas is sequentially fed into cooling equipment 15, water washing equipment 13, and drying equipment 14 for processing to obtain purified mixed hydrocarbon gas. This mixed hydrocarbon gas is used as raw material and fed into carbon nanotube production equipment. Under the action of a catalyst, it undergoes a high-temperature chemical vapor deposition reaction to produce carbon nanotubes and hydrogen.
[0045] As another specific implementation, when the carbon-containing organic compound is methane or a low-carbon olefin, it can be discharged directly from the exhaust port 36 to the carbon nanotube production equipment without decomposition, to produce carbon nanotubes and hydrogen.
[0046] Optionally, the hydrogen pipeline 8 of the gas separation device 1 is connected in parallel with the converter 3 and the hydrogen storage device to store excess hydrogen.
[0047] Optionally, the outlet of the hydrogen pipeline 8 can also be connected to a pipeline upstream of the inlet of the syngas reactor to mix the hydrogen with the gas that will be input into the syngas reactor, so that the ratio of hydrogen to carbon monoxide ultimately meets the process requirements.
[0048] The carbon nanotube production equipment, cooling equipment 12, cooling equipment 2 15, water washing equipment 13, drying equipment 1, drying equipment 2 14, dust removal equipment 17, and gas separation equipment 1 are all conventional equipment in the field, and can be selected according to specific needs.
[0049] This utility model has many advantages overall:
[0050] (1) Using carbon-containing materials, especially coal, to prepare organic compounds such as methanol, methane, and olefins at low cost, and then further produce carbon nanotubes, avoiding the use of expensive and high-purity polymer-grade ethylene and polymer-grade propylene, thereby greatly reducing the production cost of carbon nanotubes.
[0051] (2) Traditionally, the production of carbon nanotubes requires the use of polymer-grade polyethylene and polypropylene. Polyethylene and polypropylene are special chemical raw materials that can only be used in large quantities in a few large petrochemical parks designated by the state.
[0052] According to the national safety production standard "Identification of Major Hazard Installations of Hazardous Chemicals (GB18218-2009)," storing 50 tons of polyethylene and polypropylene constitutes a major hazard installation and requires a very high level of safety protection.
[0053] In addition, polymer-grade polyethylene and polypropylene raw materials require special vehicles for transportation, resulting in high transportation costs, high transportation safety risks, and high storage safety requirements.
[0054] Carbon-containing materials, such as coal, are readily available throughout the country. Using carbon-containing materials to produce carbon nanotubes and hydrogen can bypass special safety regulations, allowing factories to be built across the country. This also reduces the cost of transporting raw materials, further lowering the production cost of carbon nanotubes. The storage and use of coal are also much simpler.
[0055] (3) The hydrogen produced by the carbon nanotube production equipment is returned to the conversion furnace through the hydrogen pipeline, that is, returned to the synthesis gas production process, to adjust the H2 / CO ratio, reduce the use of CO and water vapor to generate H2 and CO2 to adjust the H2 / CO ratio, reduce the loss of C element, that is, reduce the ineffective loss of carbon-containing raw materials such as coal, that is, reduce the amount of coal consumed in the production process.
[0056] (4) The hydrogen produced by the carbon nanotube production equipment is returned to the conversion furnace through the hydrogen pipeline, that is, returned to the synthesis gas production process, to adjust the H2 / CO ratio, which greatly reduces the amount of CO2 produced. In other words, the amount of CO2 emitted into the atmosphere during the production process is greatly reduced, making the production process more low-carbon and environmentally friendly.
[0057] (5) The hydrogen produced by the carbon nanotube production equipment is returned to the converter through the hydrogen pipeline, reducing the equipment and facilities for the reaction of CO and water vapor, thereby reducing the demand and size of converter equipment and purification equipment, and reducing a large amount of equipment investment.
[0058] (6) Using carbon-containing materials as raw materials, such as coal, traditionally they can only be used to generate electricity or produce low-value products such as methanol, methane, polyethylene, and polypropylene. These traditional coal chemical products are overproduced and have very low added value. The technology of this invention converts carbon-containing elements into high-value carbon nanotubes and hydrogen, which greatly improves the economic value of traditional coal chemical industry.
Claims
1. A system for producing carbon nanotubes and hydrogen gas from a carbonaceous material, characterized by, The system comprises a synthetic gas unit, a synthetic gas conversion unit, a carbon nanotube production device and a tail gas treatment unit connected in sequence, the synthetic gas unit comprises a gasifier and a shift converter connected in sequence, carbonaceous material is input into the gasifier to be gasified to obtain crude synthetic gas, the crude synthetic gas is input into the shift converter to adjust the ratio of H2 to CO to obtain synthetic gas; The synthetic gas is converted into carbon-containing organic compounds in the synthetic gas conversion unit, and the carbon-containing organic compounds are used as raw materials for producing carbon nanotubes; the carbon nanotube production device is provided with a catalyst, and is connected to the tail gas treatment unit through a tail gas pipe; the tail gas treatment unit comprises a dust removal device, a cooling device I and a gas separation device connected in sequence, the tail gas generated by the carbon nanotube production device is subjected to dust removal and cooling, and then is input into the gas separation device to separate hydrogen gas, the hydrogen gas outlet of the gas separation device is connected to the front end of the synthetic gas unit and / or the synthetic gas conversion unit through a hydrogen gas pipeline, and the separated hydrogen gas is input into the front end of the synthetic gas unit and / or the synthetic gas conversion unit through the hydrogen gas pipeline to adjust the ratio of H2 to CO.
2. The system for producing carbon nanotubes and hydrogen gas using carbonaceous material according to claim 1, wherein The system further comprises a pretreatment device for pretreating the carbonaceous material, and the pretreatment device is selected from one or more of a crushing device, a pulverizing device, a drying device I and a granulating device.
3. The system for producing carbon nanotubes and hydrogen gas using carbonaceous material according to claim 1, wherein The carbonaceous material is selected from one of coal, petroleum coke, semicoke and biomass.
4. The system for producing carbon nanotubes and hydrogen gas using carbonaceous material according to claim 1, wherein The top of the gasifier is provided with a feeding port, the bottom of the gasifier is provided with a slag discharge port, and the side surface is provided with an exhaust port I for discharging the ash after the carbonaceous material is gasified and discharging the crude synthetic gas; The exhaust port I of the gasifier is connected to the gas inlet of the shift converter through a gas pipe, and the hydrogen gas pipeline is connected to the gas pipe to input the separated hydrogen gas and the crude synthetic gas into the shift converter.
5. The system for producing carbon nanotubes and hydrogen gas using carbonaceous material according to claim 4, wherein The top of the shift converter is provided with a gas inlet for inputting the mixed gas of the crude synthetic gas and hydrogen gas, and the bottom of the shift converter is provided with an exhaust port II for discharging the synthetic gas; A purification device is arranged between the shift converter and the synthetic gas conversion unit, the exhaust port II is connected to the inlet of the purification device through a pipeline, impurities in the synthetic gas are removed, and the outlet of the purification device is connected to the synthetic gas conversion unit through a pipeline.
6. The system for producing carbon nanotubes and hydrogen gas using carbonaceous material of claim 1, wherein, The synthetic gas conversion unit comprises a synthetic gas reactor, and the synthetic gas is converted into carbon-containing organic compounds in the synthetic gas reactor; The carbon-containing organic compounds are one of methane, ethylene, propylene and aromatic hydrocarbons, and the carbon-containing organic compounds are directly input into the carbon nanotube production device to produce carbon nanotubes.
7. The system for producing carbon nanotubes and hydrogen gas using carbonaceous material of claim 1, wherein, The synthetic gas conversion unit comprises a synthetic gas reactor, and the synthetic gas is converted into carbon-containing organic compounds in the synthetic gas reactor; the carbon-containing organic compounds are one of methanol and dimethyl ether, and a catalytic decomposition reactor, a cooling device II, a water washing device and a drying device II connected in sequence are further arranged between the synthetic gas conversion unit and the carbon nanotube reactor, the catalytic decomposition reactor is provided with a heating device and is internally provided with a molecular sieve catalyst, the carbon-containing organic compounds are input into the catalytic decomposition reactor, and the carbon-containing organic compounds are decomposed into a mixed gas containing hydrocarbons under the action of the molecular sieve catalyst.
8. The system for producing carbon nanotubes and hydrogen gas using carbonaceous material according to claim 7, wherein The top of the catalytic decomposition reactor is provided with an exhaust port four, which is connected with a cooling device two; the cooling device two, a water washing device and a drying device two are connected in series; the gas outlet at the top of the upstream side device is connected with the gas inlet of the downstream side device, so as to cool, wash and dry the mixed gas containing hydrocarbons, remove carbon dioxide, water and a small amount of oxygen-containing organic impurities, and avoid poisoning the catalyst in the carbon nanotube production device; the gas outlet of the drying device is connected with the gas inlet of the carbon nanotube reactor.