Device for extracting high-purity hydrogen and carbon monoxide from methanol pyrolysis gas
Through the device for extracting high-purity hydrogen and carbon monoxide from methanol cracking gas, the methanol buffer tank and PSA pressure-switching adsorption system are used to solve the high cost and pollution problems of the traditional coal-to-CO process, and realize the low-cost and simple operation of high-purity gas Extraction, suitable for multi-industry applications.
Patent Information
- Application Number
- CN202420147481.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-22
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2034-01-22
AI Technical Summary
The traditional coal-to-CO process has high investment costs, complex process, large area, serious pollution, and difficult to completely remove sulfur-containing compounds, making it difficult to meet the needs of other industries except the chemical industry.
The device for extracting high-purity hydrogen and carbon monoxide from methanol cracking gas is used, and the methanol cracking and PSA pressure swing adsorption are used through components such as methanol buffer tank, heat exchanger, gasifier, superheater, catalytic reactor, PSA pressure swing adsorption system. The method is used to prepare a mixture of hydrogen and carbon monoxide, which avoids the formation of sulfur-containing compounds and improves the purity of the gas.
It realizes the extraction of high-purity hydrogen and carbon monoxide with low cost, simple operation and small footprint, reducing the cost of product gas. Hydrogen and carbon monoxide do not contain sulfides, suitable for multi-industry applications and is environmentally friendly.
Smart Images
Figure CN222274120U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a device for extracting high-purity hydrogen and carbon monoxide from methanol cracking gas, belonging to the technical field of chemical industry. Background Art
[0002] CO gas is used as a raw material and is widely used in pharmaceutical intermediates, carboxyl synthesis, metallurgical industry, chemical industry, etc. The traditional method of producing CO is to produce CO from coal. The main components of coal gasification are CO, H2, O2, CO2, CH4, and N2. The content of the above components varies depending on the method of coal gasification. Then, CO gas is extracted from the coal gasification mixed gas by PSA. However, for industries other than the coal chemical industry, coal-to-CO has many inconveniences in use due to factors such as high investment cost, complex process, large land area, and serious pollution. At the same time, because coal contains S, sulfur-containing compounds are inevitably contained in the gasification gas during the gasification process. In the subsequent PSA, the sulfur-containing compounds cannot be completely removed. Utility Model Content
[0003] In order to solve the technical problems existing in the prior art, the utility model provides a device for extracting high-purity hydrogen and carbon monoxide from methanol cracking gas, which has low investment cost, simple operation, small footprint and can effectively improve the purity of product gas.
[0004] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is a device for extracting high-purity hydrogen and carbon monoxide from methanol cracking gas, comprising a methanol buffer tank, wherein the methanol buffer tank is connected to the methanol inlet of a first heat exchanger through a metering pump, the methanol outlet of the first heat exchanger is connected to the methanol inlet of a gasifier, the methanol outlet of the gasifier is connected to the methanol inlet of a superheater, the methanol outlet of the superheater is connected to the methanol inlet of a methanol catalytic reactor, the mixed gas outlet of the superheater is connected to the medium inlet of a second heat exchanger, the medium outlet of the second heat exchanger is connected to the medium inlet of the first heat exchanger, the medium outlet of the first heat exchanger is connected to the inlet of a first water cooler, the outlet of the first water cooler is connected to the inlet of a freezer, the outlet of the freezer is connected to the inlet of a gas-liquid separation tank, the liquid outlet of the gas-liquid separation tank is connected to the methanol buffer tank, the outlet of the gas-liquid separation tank is connected to the mixed gas inlet of the second heat exchanger, and the mixed gas outlet of the second heat exchanger is connected to a PSA pressure swing adsorption system.
[0005] Preferably, the gasifier is a shell and tube heat exchanger, the heat exchange medium is low-pressure steam, the superheater is a shell and tube heat exchanger, the methanol catalytic reactor is a shell and tube heat exchanger, and the heat exchange medium of the superheater and the methanol catalytic reactor are both heat transfer oil.
[0006] Preferably, the PSA pressure swing adsorption system includes a carbon dioxide PSA pressure swing adsorption component, a second water cooler, a carbon monoxide PSA pressure swing adsorption component, and a hydrogen PSA pressure swing adsorption component, and the carbon dioxide PSA pressure swing adsorption component, the second water cooler, the carbon monoxide PSA pressure swing adsorption component, and the hydrogen PSA pressure swing adsorption component are connected in sequence.
[0007] Compared with the prior art, the utility model has the following technical effects: the utility model adopts the method of methanol cracking to produce a mixed gas of hydrogen and carbon monoxide. This mixed gas does not contain sulfur compounds, is relatively easy to separate and purify, and has no harm to the catalysts in the subsequent processes; the PSA pressure swing adsorption method is adopted to obtain different products under the selective adsorption of special adsorbents. Not only can the cost of the product gas be reduced, but also the purity of the product gas can be improved. In addition, the investment cost of the device is low, the operation is simple, and the footprint is small. Methanol is a clean energy and is environmentally friendly. The raw material is high-quality industrial methanol. High-purity hydrogen can be obtained while producing CO gas, and hydrogen and CO do not contain sulfides. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Figure 1 It is a structural schematic diagram of the utility model. DETAILED DESCRIPTION
[0009] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0010] like Figure 1 As shown, a device for extracting high-purity hydrogen and carbon monoxide from methanol cracking gas comprises a methanol buffer tank 1, the methanol buffer tank 1 is connected to the methanol inlet of a first heat exchanger 3 through a metering pump 2, the methanol outlet of the first heat exchanger 3 is connected to the methanol inlet of a gasifier 4, the methanol outlet of the gasifier 4 is connected to the methanol inlet of a superheater 5, the methanol outlet of the superheater 5 is connected to the methanol inlet of a methanol catalytic reactor 6, the mixed gas outlet of the superheater 5 is connected to the medium inlet of a second heat exchanger 7, and the second The medium outlet of the heat exchanger 7 is connected to the medium inlet of the first heat exchanger 3, the medium outlet of the first heat exchanger 3 is connected to the inlet of the first water cooler 8, the outlet of the first water cooler 8 is connected to the inlet of the freezer 9, the outlet of the freezer 9 is connected to the inlet of the gas-liquid separation tank 10, the liquid outlet of the gas-liquid separation tank 10 is connected to the methanol buffer tank 1, the outlet of the gas-liquid separation tank 10 is connected to the mixed gas inlet of the second heat exchanger 7, and the mixed gas outlet of the second heat exchanger 7 is connected to the PSA pressure swing adsorption system.
[0011] In the utility model, raw material methanol is input into a methanol catalytic reactor for high-temperature cracking after heat exchange, gasification and overheating. Methanol is pumped into the methanol liquid from the methanol buffer tank to the first heat exchanger 3 by a metering pump, and preheated by the first heat exchanger 3, and then transported to the gasifier 4 through a pipeline. The pipeline is provided with flow meters, regulating valves and other flow accurate metering and control devices, and the methanol flow can be adjusted according to production needs; the rough adjustment of the methanol flow can be achieved by the metering pump, and the flow meter and the regulating valve can accurately adjust the methanol flow. The gasifier 4 is a shell and tube heat exchanger, and the heat exchange medium is low-pressure steam or other medium that provides heat to methanol until methanol is gasified but does not make the methanol temperature too high; the superheater 5 is a shell and tube heat exchanger, and the methanol catalytic reactor 6 is a shell and tube heat exchanger. The heat exchange medium of the superheater 5 and the methanol catalytic reactor 6 is heat transfer oil. The mixed gas produced by cracking is recovered by the second heat exchanger 7, the first water cooler 8, the freezer 9, and the gas-liquid separation tank 10. After recovery, the methanol flows back into the methanol buffer tank 1. The mixed gas after methanol recovery enters the PSA pressure swing adsorption system to separate CO2, CO and H2.
[0012] Among them, the PSA pressure swing adsorption system includes a carbon dioxide PSA pressure swing adsorption component 11, a second water cooler 12, a carbon monoxide PSA pressure swing adsorption component 13, and a hydrogen PSA pressure swing adsorption component 14, and the carbon dioxide PSA pressure swing adsorption component 11, the second water cooler 12, the carbon monoxide PSA pressure swing adsorption component 13, and the hydrogen PSA pressure swing adsorption component 14 are connected in sequence. The carbon dioxide PSA pressure swing adsorption component 11 and the hydrogen PSA pressure swing adsorption component 14 both use multi-stage adsorption towers, the adsorption towers are eight towers, and the towers are filled with adsorbents. The carbon monoxide PSA pressure swing adsorption component 13 is a PSA adsorption tower, the adsorption towers are six towers, and the towers are filled with adsorbents, and there are multiple types of PSA adsorbents, depending on the type and quality requirements of the product gas.
[0013] When used specifically:
[0014] S1: Raw material pretreatment: pressurize, meter, vaporize and superheat methanol to obtain superheated methanol gas with a temperature between 220 and 300°C and a pressure between 0.4 and 1.9 MPag;
[0015] S2: Cracking reaction: The obtained superheated methanol gas is introduced into a methanol catalytic reactor, and a cracking reaction occurs in the catalyst bed to obtain a mixed gas whose main products are hydrogen and carbon monoxide. In addition to the main products hydrogen (content accounting for about 64-66% of the total volume) and carbon monoxide (content accounting for about 28-30% of the total volume), the mixed gas also contains a small amount of methane, carbon dioxide, dimethyl ether and trace macromolecular organic matter and other by-products and unreacted methanol vapor, accounting for about 4% of the total gas volume;
[0016] S3: Heat recovery: The high-temperature cracking gas from the reactor is heat-exchanged with the PSA raw gas, and then heat-exchanged with the methanol raw material to recover the heat of the cracking gas, and the raw material is preheated at the same time to achieve the purpose of energy saving of the device; the PSA raw gas enters the heat exchanger and is preheated to 60°C, and the raw methanol is preheated to 80°C;
[0017] S4: Unreacted product recovery: The cracked gas obtained in S3 is cooled to room temperature by a water cooler, and then enters a freezer to be cooled to about 10~-10℃ to liquefy and recover the unreacted methanol. The gas enters a gas-liquid separator, in which a wire mesh foam collector is provided to separate the liquid droplets entrained in the gas from the gas;
[0018] S5: Removal of by-products: The cracked gas obtained in S4 is subjected to PSA pressure swing adsorption to remove carbon dioxide and macromolecular by-products, and the content of CO2 after removal is below 0.1%;
[0019] S6: Extracting high-purity CO: The de-CO2 gas obtained in step S5 is purified by PSA pressure swing adsorption method, and the product gas CO is obtained by vacuuming the bottom of the tower by a vacuum pump. The CO product yield is more than 90%, and the vacuum pump adopts a screw type or claw type vacuum pump;
[0020] S7: preparing high-purity hydrogen: purifying the gas output from the other end of the adsorption tower in step S6 by PSA pressure swing adsorption to obtain high-purity hydrogen, with a hydrogen yield of up to 90%;
[0021] S8: PSA tail gas recovery and utilization: The adsorbed tail gas produced by S4, S5 and S6 is transported to the catalytic combustion furnace to heat the heat transfer oil and provide heat for the reaction of S2 and the overheating of S1.
[0022] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.
Claims
1. A device for extracting high-purity hydrogen and carbon monoxide from methanol cracking gas, comprising a methanol buffer tank, characterized in that: The methanol buffer tank is connected to the methanol inlet of the first heat exchanger through a metering pump, the methanol outlet of the first heat exchanger is connected to the methanol inlet of the gasifier, the methanol outlet of the gasifier is connected to the methanol inlet of the superheater, the methanol outlet of the superheater is connected to the methanol inlet of the methanol catalytic reactor, the mixed gas outlet of the superheater is connected to the medium inlet of the second heat exchanger, the medium outlet of the second heat exchanger is connected to the medium inlet of the first heat exchanger, the medium outlet of the first heat exchanger is connected to the inlet of the first water cooler, the outlet of the first water cooler is connected to the inlet of the freezer, the outlet of the freezer is connected to the inlet of the gas-liquid separation tank, the liquid outlet of the gas-liquid separation tank is connected to the methanol buffer tank, the outlet of the gas-liquid separation tank is connected to the mixed gas inlet of the second heat exchanger, and the mixed gas outlet of the second heat exchanger is connected to a PSA pressure swing adsorption system.
2. The device for extracting high-purity hydrogen and carbon monoxide from methanol cracking gas according to claim 1, characterized in that: The gasifier is a shell and tube heat exchanger, the heat exchange medium is low-pressure steam, the superheater is a shell and tube heat exchanger, the methanol catalytic reactor is a shell and tube heat exchanger, and the heat exchange medium of the superheater and the methanol catalytic reactor is heat transfer oil.
3. The device for extracting high-purity hydrogen and carbon monoxide from methanol cracking gas according to claim 1, characterized in that: The PSA pressure swing adsorption system includes a carbon dioxide PSA pressure swing adsorption component, a second water cooler, a carbon monoxide PSA pressure swing adsorption component, and a hydrogen PSA pressure swing adsorption component, and the carbon dioxide PSA pressure swing adsorption component, the second water cooler, the carbon monoxide PSA pressure swing adsorption component, and the hydrogen PSA pressure swing adsorption component are connected in sequence.