A device and method for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming

Abstract

A device and method for direct steam reforming of high-temperature coke oven gas to produce hydrogen, relating to the field of hydrogen production technology in energy and chemical engineering, includes a reformer, a primary cyclone separator, heat recovery equipment I, a high-temperature filter, heat recovery equipment II, a water washing tower, a syngas compressor, a shift converter, a low-temperature methanol washing device, a steam jet pump, a steam drum, a circulating pump, a cooler, and a secondary cyclone separator. The top reactant gas inlet of the reformer is connected to an oxygen pipeline, and the top side reactant gas inlet is connected to the outlet pipeline of the high-temperature coke oven gas and high-temperature steam mixture from the steam jet pump. Without additional mechanical transmission equipment, the pressure of high-temperature coke oven gas under slightly positive pressure within the range of atmospheric pressure or several hundred Pascals can be increased several times. Due to the increased pressure, the density of the gas medium in the system increases several times accordingly, effectively improving the unit volume reaction intensity of the reformer equipment and significantly reducing the fixed investment costs of the reformer and its downstream equipment and process pipelines.

Description

Technical Field

[0001] The invention relates to the technical field of energy chemical hydrogen production, and in particular to a device and method for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming. Background Art

[0002] As a highly efficient and clean energy source with high calorific value, no pollution and abundant sources, the demand for hydrogen has been growing in recent years.

[0003] At present, the main methods of large-scale hydrogen production are fossil fuel hydrogen production and water electrolysis hydrogen production. However, fossil fuels are facing depletion, and water electrolysis hydrogen production consumes a lot of energy. Coke oven gas is the main by-product of the coking process. One ton of coal can produce about 330m3 of hydrogen in the coking process. 3 Coke oven gas. China is the world's largest producer of coke oven gas, with an annual output of 190 billion m 3 , because the contents of hydrogen and C1 and C2 light hydrocarbons account for about 45% and 28% of the total (mass fraction) respectively, it is an ideal raw material for hydrogen production.

[0004] At present, hydrogen production from coke oven gas is mainly achieved by separating the original hydrogen in the coke oven gas discharged from the coke oven carbonization chamber by physical methods. Since the coke oven gas discharged from the coke oven carbonization chamber at 700-900℃ contains tar accounting for about 30% of the total gas, it is called coke oven waste gas. Tar has a high viscosity and is easy to clog pipelines and other equipment. It needs to be removed by spraying ammonia water, but spraying ammonia water reduces the temperature of coke oven gas to below 90℃, resulting in a large amount of sensible heat waste. In addition, the physical method can only separate the original hydrogen in the coke oven gas, but cannot effectively utilize the carbon monoxide and hydrocarbons in it, which account for about 35%. At the same time, the purification and chemical recovery process is also the most important source of pollutant emissions in the coking plant, especially the phenol-cyanide wastewater produced, which has complex components and is the most difficult type of industrial wastewater to treat.

[0005] In the patent application with application number 201910045562.0 and publication number CN109485016A, a system and method for producing hydrogen or ammonia by direct steam reforming of coke oven raw gas is involved. The raw gas coming out of the coke oven directly enters the non-catalytic reforming furnace, first reacts with oxygen to raise the temperature to 1300~1500℃, and then reforms with water vapor to generate synthesis gas mainly composed of H2 and CO. The synthesis gas is converted into CO, desulfurized and separated into gases to obtain hydrogen or generate ammonia. In the system and method, the coke oven raw gas at normal pressure or a few hundred Pa slightly positive pressure coming out of the coke oven is directly sent to the reforming furnace. The outlet of the reforming furnace passes through the heat exchange equipment, cyclone dust removal equipment and high-temperature induced draft fan in sequence, and relies on the high-temperature induced draft fan for air extraction and transportation, and then is sent to the carbon monoxide conversion furnace. That is, the reforming furnace, heat exchange equipment, cyclone dust removal equipment and conversion furnace equipment and their corresponding gas phase connecting pipelines between the reforming furnace and the carbon monoxide conversion furnace are all in a slightly negative pressure or slightly positive pressure state. When the device scale is the same, the investment cost of equipment and pipelines will inevitably increase greatly compared with the pressurized operation condition. At the same time, the gas phase outlet of the cyclone dust removal equipment used in the process flow will still contain a relatively high concentration of fly ash dust. The high-temperature centrifugal fan arranged downstream of the cyclone dust removal equipment is operated in a dusty atmosphere for a long time, and the normal operation cycle will be greatly shortened. In addition, the dust will also have an adverse effect on the conversion catalyst bed in the conversion furnace arranged downstream of the induced draft fan, which is easy to reduce the catalyst activity and cause the bed to be blocked. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a device and method for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming to solve the problems raised in the above background technology.

[0007] The present invention is achieved through the following technical solutions:

[0008] A device for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming, characterized in that it comprises a reforming furnace, a primary cyclone separator, a heat recovery device I, a high-temperature filter, a heat recovery device II, a water scrubber, a synthesis gas compressor, a conversion device, a low-temperature methanol scrubbing device, a steam jet pump, a steam drum, a circulating pump, a cooler and a secondary cyclone separator;

[0009] The reaction gas inlet at the top of the reforming furnace is connected to the oxygen pipeline, the reaction gas inlet at the top side is connected to the outlet pipeline of the high-temperature coke oven raw gas and high-temperature steam mixed gas from the steam jet pump, and the crude synthesis gas outlet at the bottom side is connected to the inlet pipeline of the first-stage cyclone separator; the dust-containing crude synthesis gas outlet after gas-solid separation of the first-stage cyclone separator is connected to the high-temperature crude synthesis gas inlet pipeline of the heat recovery device I; the crude synthesis gas outlet after heat exchange and cooling of the heat recovery device I is connected to the inlet pipeline of the high-temperature filter; the synthesis gas outlet after precise dry filtration of the high-temperature filter is connected to the top synthesis gas inlet pipeline of the heat recovery device II; the synthesis gas outlet at the bottom side of the heat recovery device II after further heat exchange and cooling is connected to the synthesis gas inlet pipeline at the bottom side of the water washing tower; the hot synthesis gas outlet at the top of the water washing tower after further dust removal and purification is connected to the inlet pipeline of the synthesis gas compressor; the synthesis gas outlet pipeline after compression and pressure increase of the synthesis gas compressor is connected to the synthesis gas inlet pipeline of the conversion device; the conversion gas outlet of the conversion device after carbon monoxide conversion is connected to the synthesis gas inlet pipeline of the low-temperature methanol washing device.

[0010] In another aspect of the present invention, part or all of the inside of the reforming furnace, the first-stage cyclone separator, the non-heat exchange area of ​​the heat recovery equipment I near the high-temperature raw synthesis gas inlet side, and the steam jet pump are lined with refractory bricks or refractory castables.

[0011] In another aspect of the present invention, the water / steam side of the heat recovery equipment I is connected to the steam drum through a saturated water / steam pipeline, and a part of the produced superheated steam outlet pipeline is connected to the superheated steam inlet pipeline of the steam jet pump after being reduced in pressure, and a part of it is connected to the external by-product steam pipeline through a regulating valve.

[0012] In another aspect of the present invention, the heat recovery equipment II adopts a vertical fire tube type, the synthesis gas is cooled from top to bottom along the tube side, and the boiler feed water is heated from bottom to top along the shell side. The heated boiler feed water is connected to the boiler feed water inlet pipeline of the end head of the steam drum from the top side outlet of the shell side of the heat recovery equipment II.

[0013] In another aspect of the present invention, the process water outlet at the bottom of the water washing tower is connected to the inlet pipeline of the circulation pump; a part of the circulating pump outlet is connected to the hot side inlet of the cooler process water, and a part is connected to the external waste water pipeline through a regulating valve; the cooling side outlet of the cooler process water is connected to the process water inlet pipeline on the top side of the water washing tower.

[0014] In another aspect of the present invention, the working fluid of the steam jet pump is the decompressed superheated steam from the heat recovery device I, and the induced fluid is the high-temperature coke oven raw gas from the coke oven raw gas collecting pipe.

[0015] In another aspect of the present invention, the steam jet pump is composed of one ejector or a preset number of ejectors connected in series or in parallel.

[0016] In another aspect of the present invention, a secondary cyclone separator is provided between the outlet of the raw synthesis gas after indirect heat exchange in the heat recovery device I and the inlet of the high-temperature filter.

[0017] A method for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming, comprising:

[0018] The coke oven raw gas with a temperature of 550-800°C from the coke oven raw gas collecting pipe enters the steam jet pump from the injection fluid inlet of the steam jet pump, and after being drawn, mixed and pressurized by the superheated steam of the working fluid of the steam jet pump, enters the inside of the catalytic reforming furnace from the top side inlet of the reforming furnace. The superheated steam and high-temperature raw gas after pressurization are quickly mixed with the oxygen sprayed from the top of the reforming furnace and a high-temperature combustion reaction occurs, which instantly makes the temperature in the reforming furnace reach 1200-1500°C, and the carbon-containing organic matter in the coke oven raw gas undergoes a reforming reaction with water vapor to generate a synthesis gas mainly composed of hydrogen and carbon monoxide;

[0019] The boiler feed water with a pressure of 4.0~6.0Mpa from the boiler feed water pipeline first enters the shell side of the heat recovery device II for indirect heat exchange and temperature rise. After the temperature rises to 170~210℃, it enters the steam drum and forms an indirect heating and temperature rise system with the heat recovery device I through the steam drum. After indirect heat exchange with the heat recovery device I, superheated steam with a pressure of 3.0~5.0Mpa and a temperature of 400~600℃ is obtained. Part of the superheated steam is reduced in pressure by the pressure reducing valve and enters the steam jet pump as the working fluid, and the rest of the superheated steam is sent out as by-product steam.

[0020] The high-temperature raw synthesis gas from the side outlet of the bottom of the reforming furnace enters the primary cyclone separator, and some carbon-containing solid fly ash particles entrained in the raw synthesis gas are separated by the primary cyclone separator;

[0021] The high-temperature raw synthesis gas from the top outlet of the first-stage cyclone separator enters the heat recovery device I, and the temperature is reduced to 350~500℃ through indirect heat exchange with water / steam, and then enters the high-temperature filter;

[0022] The 350~500℃ raw synthesis gas after further dust removal from the high temperature filter enters the heat recovery device II, and indirectly exchanges heat with the boiler feed water, reducing the temperature to 150~250℃, and then enters the water scrubber;

[0023] The hot synthesis gas from the top of the water scrubber enters the synthesis gas compressor for compression and transportation, and then enters the shift device. Under the action of the shift catalyst, the carbon monoxide and water vapor in it undergo a shift reaction to produce carbon dioxide and hydrogen to obtain shift gas;

[0024] The conversion gas from the conversion device enters the low-temperature methanol washing device to obtain hydrogen product, liquid carbon dioxide by-product and sulfur by-product.

[0025] In another aspect of the present invention, when the working fluid superheated steam of the steam jet pump is in normal operation, it is the decompressed superheated steam from the heat recovery device I, with a temperature of 400~600℃ and a pressure of 0.6~4.0Mpa; the reaction pressure of the reforming furnace is 0.1~1.0Mpa.

[0026] In another aspect of the present invention, the process water outlet at the bottom of the water washing tower is transported to a cooler through a circulation pump and cooled to 100-150° C. in the cooler.

[0027] In another aspect of the present invention, the outlet of heat recovery device I enters a secondary cyclone separator to further separate part of the carbonaceous solid fly ash particles entrained in the raw synthesis gas, and the top outlet of the secondary cyclone separator enters a high-temperature filter.

[0028] The beneficial effects of the present invention are:

[0029] (1) The steam jet pump pressurizing equipment can double the pressure of the slightly positive pressure high-temperature coke oven raw gas within the pressure range of normal pressure or several hundred Pa without the need for additional mechanical transmission equipment, so that the steam reforming system can be operated under pressurized state, overcoming the pressure loss limitation in the downstream process flow. At the same time, due to the increase in pressure, the density of the gas medium in the system is doubled accordingly, effectively improving the reaction intensity per unit volume of the reforming furnace equipment, and significantly reducing the fixed investment cost of the reforming furnace and its downstream equipment and process pipelines.

[0030] (2) The steam jet pump pressurizing equipment is used. This equipment can be used as a high-temperature raw coal gas pressurizing and conveying equipment, and at the same time it is a good mixer of steam and high-temperature raw coal gas. It can make two fluids of different pressures, namely water vapor and high-temperature raw coal gas, mix with each other, exchange energy, and form a mixed fluid with a certain pressure to be conveyed to the reforming furnace, thereby improving the uniformity of mixing and contact time of the two reactants, and correspondingly effectively improving the reforming reaction conversion rate.

[0031] (3) A high-temperature cyclone separator is installed on the high-temperature outlet gas production pipeline of the reforming furnace to separate the carbon-containing fly ash particles entrained in the outlet gas of the reforming furnace, which greatly reduces the dust concentration in the gas entering the heat recovery equipment I, and correspondingly greatly reduces the wear and dust accumulation of the heat recovery equipment. It not only increases the heat transfer coefficient on the gas side of the heat recovery equipment and reduces the heat exchange area, but also effectively improves the service life of the heat recovery equipment.

[0032] (4) The heat recovery equipment I for the high temperature section of the reforming furnace outlet gas and the heat recovery equipment II for the low temperature section are independently arranged, and the heat recovery equipment II for the low temperature section adopts a vertical fire tube type, thereby avoiding the dust accumulation and scaling problems caused by the horizontal or water tube type, and the heat exchange efficiency and service life are effectively improved and extended respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the structure of embodiment 1 and the principle of embodiment 3 of the present invention.

[0034] Figure 2 It is a schematic diagram of the structure of embodiment 2 and the principle of embodiment 4 of the present invention.

[0035] In the attached figure: 1. reforming furnace, 2. primary cyclone separator, 3. heat recovery equipment I, 4. high temperature filter, 5. heat recovery equipment II, 6. water washing tower, 7. synthesis gas compressor, 8. conversion device, 9. low-temperature methanol washing device, 10. steam jet pump, 11. steam drum, 12. circulation pump, 13. cooler, 14. secondary cyclone separator, 15. oxygen, 16. coke oven raw gas, 17. by-product steam, 18. boiler feed water, 19. waste water, 20. liquid carbon dioxide by-product, 21. hydrogen product, 22. sulfur by-product. DETAILED DESCRIPTION

[0036] The following is a further description of the embodiments of the present invention in conjunction with the accompanying drawings and embodiments:

[0037] In the description of the present invention, it is necessary to understand that the description indicating the orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present invention.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example 1

[0039] A device for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming comprises a reforming furnace 1, a primary cyclone separator 2, a heat recovery device I3, a high-temperature filter 4, a heat recovery device II5, a water scrubber 6, a synthesis gas compressor 7, a conversion device 8, a low-temperature methanol scrubbing device 9, a steam jet pump 10, a steam drum 11, a circulating pump 12, a cooler 13 and a secondary cyclone separator 14.

[0040] The top reaction gas inlet of the reforming furnace 1 is connected to the oxygen pipeline, the top side reaction gas inlet is connected to the high-temperature coke oven raw gas and high-temperature steam mixed gas outlet pipeline from the steam jet pump 10, and the bottom side crude synthesis gas outlet is connected to the inlet pipeline of the first-stage cyclone separator 2; the dust-containing crude synthesis gas outlet after gas-solid separation of the first-stage cyclone separator 2 is connected to the high-temperature crude synthesis gas inlet pipeline of the heat recovery device Ⅰ3; the crude synthesis gas outlet of the heat recovery device Ⅰ3 after heat exchange and cooling is connected to the inlet pipeline of the high-temperature filter 4; the synthesis gas outlet of the high-temperature filter 4 after precise dry filtration is connected to the top of the heat recovery device Ⅱ5 The synthesis gas inlet pipeline is connected; the synthesis gas outlet at the bottom side of the heat recovery device Ⅱ5 after further heat exchange and cooling is connected to the synthesis gas inlet pipeline at the bottom side of the water washing tower 6; the hot synthesis gas outlet at the top of the water washing tower 6 after further dust removal and purification is connected to the synthesis gas compressor inlet pipeline; the synthesis gas outlet pipeline of the synthesis gas compressor 7 after compression and pressure increase is connected to the synthesis gas inlet pipeline of the conversion device; the conversion gas outlet of the conversion device after carbon monoxide conversion is connected to the synthesis gas inlet pipeline of the low-temperature methanol washing device; the export product of the low-temperature methanol washing device is hydrogen, as well as by-product liquid carbon dioxide and sulfur products.

[0041] The reforming furnace 1 is a non-catalytic reforming furnace, and the inner side of the reforming furnace is made of refractory bricks or refractory castables.

[0042] The primary cyclone separator 2 is lined with refractory bricks or refractory castables.

[0043] The heat recovery equipment I3 is lined with refractory bricks or refractory castables at the non-heat exchange part near the high-temperature raw synthesis gas inlet side.

[0044] The water / steam side of the heat recovery device Ⅰ3 is connected to the steam drum 11 through a saturated water / steam pipeline. A part of the produced superheated steam outlet pipeline is connected to the superheated steam inlet pipeline of the steam jet pump 10 after being reduced in pressure, and a part of it is connected to the external by-product steam pipeline through a regulating valve.

[0045] The high temperature filter 4 can be made of a metal filter element or a ceramic filter element.

[0046] The heat recovery equipment Ⅱ5 adopts a vertical fire tube type. The synthesis gas is cooled from top to bottom along the tube side, and the boiler feed water is heated from bottom to top along the shell side. The heated boiler feed water is connected to the boiler feed water inlet pipeline of the end head of the steam drum 11 from the top side outlet of the shell side of the heat recovery equipment Ⅱ5.

[0047] The water washing tower 6 adopts an external circulation indirect heat exchange method. The process water outlet at the bottom of the water washing tower 6 is connected to the inlet pipeline of the circulation pump 12; a part of the outlet of the circulation pump 12 is connected to the inlet of the process water hot side of the cooler 13, and a part is connected to the external waste water pipeline through a regulating valve; the process water cooling side outlet of the cooler 13 is connected to the process water inlet pipeline on the top side of the water washing tower 6.

[0048] The working fluid of the steam jet pump 10 is the decompressed superheated steam from the heat recovery device Ⅰ3, and the injection fluid is the high-temperature coke oven raw gas from the coke oven raw gas collecting pipe.

[0049] The steam jet pump 10 is lined with refractory bricks or refractory castables.

[0050] The steam jet pump 10 is composed of one ejector or several ejectors connected in series or in parallel.

[0051] When the device for producing hydrogen by pressurizing direct steam reforming of high-temperature coke oven raw gas is in use, the coke oven raw gas with a temperature of 550-800°C from the coke oven raw gas collecting pipe enters the steam jet pump 10 from the injection fluid inlet of the steam jet pump 10, and after being drawn, mixed and pressurized by the working fluid superheated steam of the steam jet pump 10, enters the inside of the catalytic reforming furnace from the top side inlet of the reforming furnace 1. The superheated steam and high-temperature raw gas after pressurization are quickly mixed with the oxygen sprayed from the top of the reforming furnace and a high-temperature combustion reaction occurs, which instantly raises the temperature in the reforming furnace to 120°C. At 0~1500℃, the carbon-containing organic matter in the coke oven raw gas reacts with water vapor to form a synthesis gas mainly composed of hydrogen and carbon monoxide; the boiler feed water with a pressure of 4.0~6.0Mpa from the boiler feed water pipeline first enters the shell side of the heat recovery equipment Ⅱ5 for indirect heat exchange and heating, and after the temperature rises to 170~210℃, it enters the steam drum 11 and forms an indirect heating and heating system with the heat recovery equipment Ⅰ3 through the steam drum 11. After the indirect heat exchange of the heat recovery equipment Ⅰ3, a superheated gas with a pressure of 3.0~5.0Mpa and a temperature of 400~600℃ is obtained. Steam, of which part of the superheated steam is reduced in pressure by a pressure reducing valve and then enters a steam jet pump as a working fluid, and the rest of the superheated steam is sent out as a by-product steam; the high-temperature crude synthesis gas from the bottom side outlet of the reforming furnace enters the primary cyclone separator 2, and part of the carbonaceous solid fly ash particles entrained in the crude synthesis gas are separated by the primary cyclone separator 2; the high-temperature crude synthesis gas from the top outlet of the primary cyclone separator 2 enters the heat recovery device Ⅰ3, and the temperature is reduced to 350~500℃ through indirect heat exchange with water / steam, and then enters the high-temperature filter 4; from the high-temperature filter into After one-step dust removal, the 350~500℃ raw synthesis gas enters the heat recovery device II, and indirectly exchanges heat with the boiler feed water, the temperature is reduced to 150~250℃, and then enters the water scrubber 6; the hot synthesis gas from the top of the water scrubber 6 enters the synthesis gas compressor for compression and transportation, and then enters the conversion device. Under the action of the conversion catalyst, the carbon monoxide and water vapor therein undergo a conversion reaction to generate carbon dioxide and hydrogen to obtain conversion gas; the conversion gas from the conversion device enters the low-temperature methanol washing device to obtain hydrogen products, liquid carbon dioxide by-products and sulfur by-products. When the working fluid superheated steam of the steam jet pump 10 is in normal production operation, it is the superheated steam after decompression from the heat recovery device I, with a temperature of 400~600℃ and a pressure of 0.6~4.0Mpa; the reaction pressure of the reforming furnace 1 is 0.1~1.0Mpa; the process water outlet at the bottom of the water scrubber 6 is transported to the cooler 13 through the circulating pump 12, and cooled to 100~150℃ in the cooler 13.

[0052] The beneficial effects of this device for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming are:

[0053] (1) The steam jet pump pressurizing equipment can double the pressure of the slightly positive pressure high-temperature coke oven raw gas within the pressure range of normal pressure or several hundred Pa without the need for additional mechanical transmission equipment, so that the steam reforming system can be operated under pressurized state, overcoming the pressure loss limitation in the downstream process flow. At the same time, due to the increase in pressure, the density of the gas medium in the system is doubled accordingly, effectively improving the reaction intensity per unit volume of the reforming furnace equipment, and significantly reducing the fixed investment cost of the reforming furnace and its downstream equipment and process pipelines.

[0054] (2) The steam jet pump pressurizing equipment is used. This equipment can be used as a high-temperature raw coal gas pressurizing and conveying equipment, and at the same time it is a good mixer of steam and high-temperature raw coal gas. It can make two fluids of different pressures, namely water vapor and high-temperature raw coal gas, mix with each other, exchange energy, and form a mixed fluid with a certain pressure to be conveyed to the reforming furnace, thereby improving the uniformity of mixing and contact time of the two reactants, and correspondingly effectively improving the reforming reaction conversion rate.

[0055] (3) A high-temperature cyclone separator is installed on the high-temperature outlet gas production pipeline of the reforming furnace to separate the carbon-containing fly ash particles entrained in the outlet gas of the reforming furnace, which greatly reduces the dust concentration in the gas entering the heat recovery equipment I, and correspondingly greatly reduces the wear and dust accumulation of the heat recovery equipment. It not only increases the heat transfer coefficient on the gas side of the heat recovery equipment and reduces the heat exchange area, but also effectively improves the service life of the heat recovery equipment.

[0056] (4) The heat recovery equipment I for the high temperature section of the reforming furnace outlet gas and the heat recovery equipment II for the low temperature section are independently arranged, and the heat recovery equipment II for the low temperature section adopts a vertical fire tube type, thereby avoiding the dust accumulation and scaling problems caused by the horizontal or water tube type, and the heat exchange efficiency and service life are effectively improved and extended respectively. Example 2

[0057] In the present embodiment, a set of secondary cyclone separators 14 is arranged between the crude synthesis gas outlet after indirect heat exchange of the heat recovery device Ⅰ in embodiment 1 and the crude synthesis gas inlet of the high-temperature filter 4, so as to further separate part of the carbonaceous solid fly ash particles entrained in the crude synthesis gas, reduce the fly ash concentration at the high-temperature filter inlet, and correspondingly reduce the filtering load of the high-temperature filter. Example 3

[0058] A method for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming, comprising:

[0059] (1) The coke oven raw gas with a temperature of 550-800°C from the coke oven raw gas collecting pipe enters the steam jet pump 10 from the injection fluid inlet of the steam jet pump 10, and after being drawn, mixed and pressurized by the superheated steam of the working fluid of the steam jet pump 10, enters the inside of the catalytic reforming furnace from the top side inlet of the reforming furnace 1. The superheated steam and the high-temperature raw gas after pressurization are quickly mixed with the oxygen injected from the top of the reforming furnace and a high-temperature combustion reaction occurs, which instantly makes the temperature in the reforming furnace reach 1200-1500°C. The carbon-containing organic matter in the coke oven raw gas undergoes a reforming reaction with water vapor to generate a synthesis gas mainly composed of hydrogen and carbon monoxide.

[0060] (2) The boiler feed water with a pressure of 4.0~6.0Mpa from the boiler feed water pipeline first enters the shell side of the heat recovery device Ⅱ5 for indirect heat exchange and temperature rise. After the temperature rises to 170~210℃, it enters the steam drum 11 and forms an indirect heating and temperature rise system with the heat recovery device Ⅰ3 through the steam drum 11. After indirect heat exchange with the heat recovery device Ⅰ3, superheated steam with a pressure of 3.0~5.0Mpa and a temperature of 400~600℃ is obtained. Part of the superheated steam is reduced in pressure by the pressure reducing valve and then enters the steam jet pump as the working fluid, and the rest of the superheated steam is sent out as by-product steam;

[0061] (3) The high-temperature raw synthesis gas from the side outlet of the bottom of the reforming furnace enters the primary cyclone separator 2, and some carbon-containing solid fly ash particles entrained in the raw synthesis gas are separated by the primary cyclone separator 2;

[0062] (4) The high-temperature raw synthesis gas from the top outlet of the primary cyclone separator 2 enters the heat recovery device I3, and is reduced in temperature to 350-500°C through indirect heat exchange with water / steam, and then enters the high-temperature filter 4;

[0063] (5) After further dust removal from the high temperature filter, the 350-500°C crude synthesis gas enters the heat recovery device II, and indirectly exchanges heat with the boiler feed water, reducing the temperature to 150-250°C, and then enters the water scrubber 6;

[0064] (6) The hot synthesis gas from the top of the water scrubber 6 enters the synthesis gas compressor for compression and transportation, and then enters the shift device. Under the action of the shift catalyst, the carbon monoxide and water vapor in the synthesis gas undergo a shift reaction to generate carbon dioxide and hydrogen, thereby obtaining a shift gas;

[0065] (7) The conversion gas from the conversion device enters the low-temperature methanol washing device to obtain hydrogen product, liquid carbon dioxide by-product and sulfur by-product.

[0066] When the working fluid of the steam jet pump 10 is in normal operation, the superheated steam is the decompressed superheated steam from the heat recovery device I, with a temperature of 400-600°C and a pressure of 0.6-4.0 MPa.

[0067] The reaction pressure of the reforming furnace 1 is between 0.1 and 1.0 MPa.

[0068] The process water outlet at the bottom of the water washing tower 6 is transported to the cooler 13 through the circulation pump 12, and is cooled to 100-150°C in the cooler 13.

[0069] The beneficial effects of this method of producing hydrogen by pressurizing high-temperature coke oven waste gas with direct steam reforming are:

[0070] (1) The steam jet pump pressurizing equipment can double the pressure of the slightly positive pressure high-temperature coke oven raw gas within the pressure range of normal pressure or several hundred Pa without the need for additional mechanical transmission equipment, so that the steam reforming system can be operated under pressurized state, overcoming the pressure loss limitation in the downstream process flow. At the same time, due to the increase in pressure, the density of the gas medium in the system is doubled accordingly, effectively improving the reaction intensity per unit volume of the reforming furnace equipment, and significantly reducing the fixed investment cost of the reforming furnace and its downstream equipment and process pipelines.

[0071] (2) The steam jet pump pressurizing equipment is used. This equipment can be used as a high-temperature raw coal gas pressurizing and conveying equipment, and at the same time it is a good mixer of steam and high-temperature raw coal gas. It can make two fluids of different pressures, namely water vapor and high-temperature raw coal gas, mix with each other, exchange energy, and form a mixed fluid with a certain pressure to be conveyed to the reforming furnace, thereby improving the uniformity of mixing and contact time of the two reactants, and correspondingly effectively improving the reforming reaction conversion rate.

[0072] (3) A high-temperature cyclone separator is installed on the high-temperature outlet gas production pipeline of the reforming furnace to separate the carbon-containing fly ash particles entrained in the outlet gas of the reforming furnace, which greatly reduces the dust concentration in the gas entering the heat recovery equipment I, and correspondingly greatly reduces the wear and dust accumulation of the heat recovery equipment. It not only increases the heat transfer coefficient on the gas side of the heat recovery equipment and reduces the heat exchange area, but also effectively improves the service life of the heat recovery equipment.

[0073] (4) The heat recovery equipment I for the high temperature section of the reforming furnace outlet gas and the heat recovery equipment II for the low temperature section are independently arranged, and the heat recovery equipment II for the low temperature section adopts a vertical fire tube type, thereby avoiding the dust accumulation and scaling problems caused by the horizontal or water tube type, and the heat exchange efficiency and service life are effectively improved and extended respectively. Example 4

[0074] In this embodiment, based on the embodiment 3, the outlet of the heat recovery device I enters the secondary cyclone separator 14 to further separate part of the carbonaceous solid fly ash particles entrained in the raw synthesis gas, and the top outlet of the secondary cyclone separator 14 enters the high-temperature filter 4.

[0075] In conclusion, the above is only a preferred embodiment of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the patent of the present invention.

Claims

1. A device for producing hydrogen by direct steam reforming of high-temperature coke oven raw gas under pressure, characterized in that: It comprises a reforming furnace (1), a primary cyclone separator (2), a heat recovery device I (3), a high temperature filter (4), a heat recovery device II (5), a water washing tower (6), a synthesis gas compressor (7), a conversion device (8), a low temperature methanol washing device (9), a steam jet pump (10), a steam drum (11), a circulating pump (12), a cooler (13) and a secondary cyclone separator (14); The top reaction gas inlet of the reforming furnace (1) is connected to an oxygen pipeline, the top side reaction gas inlet is connected to an outlet pipeline of a high-temperature coke oven raw gas and a high-temperature steam mixed gas from a steam jet pump (10), and the bottom side crude synthesis gas outlet is connected to an inlet pipeline of a primary cyclone separator (2); the dust-containing crude synthesis gas outlet after gas-solid separation of the primary cyclone separator (2) is connected to an inlet pipeline of a high-temperature crude synthesis gas of a heat recovery device I (3); the crude synthesis gas outlet after heat exchange and cooling of the heat recovery device I (3) is connected to an inlet pipeline of a high-temperature filter (4); the synthesis gas outlet after precise dry filtration of the high-temperature filter (4) is connected to an inlet pipeline of a top synthesis gas of a heat recovery device II (5); the synthesis gas outlet after further heat exchange and cooling of the bottom side of the heat recovery device II (5) is connected to an inlet pipeline of a bottom side synthesis gas of a water washing tower (6); the water washing tower The hot synthesis gas outlet after further dust removal and purification at the top of (6) is connected to the inlet pipeline of the synthesis gas compressor; the synthesis gas outlet pipeline of the synthesis gas compressor (7) after compression and pressure increase is connected to the synthesis gas inlet pipeline of the conversion device; the conversion gas outlet of the conversion device after carbon monoxide conversion is connected to the synthesis gas inlet pipeline of the low-temperature methanol washing device; the inside of the reforming furnace, the first-stage cyclone separator (2), the non-heat exchange part near the high-temperature raw synthesis gas inlet side of the heat recovery device I (3), and the steam jet pump (10) are partially or completely lined with refractory bricks or refractory castables; the water / steam side of the heat recovery device I (3) is connected to the steam drum (11) through a saturated water / steam pipeline, and a part of the superheated steam outlet pipeline produced is connected to the superheated steam inlet pipeline of the steam jet pump (10) after pressure reduction, and a part is connected to the pipeline for sending by-product steam through a regulating valve.

2. The device for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming according to claim 1, characterized in that: The heat recovery device II (5) adopts a vertical fire tube type. The synthesis gas is cooled from top to bottom along the tube side, and the boiler feed water is heated from bottom to top along the shell side. The heated boiler feed water is connected to the boiler feed water inlet pipeline of the end head of the steam drum (11) from the top side outlet of the shell side of the heat recovery device II (5).

3. The device for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming according to claim 1, characterized in that: The process water outlet at the bottom of the water washing tower (6) is connected to the inlet pipeline of the circulation pump (12); a part of the outlet of the circulation pump (12) is connected to the inlet of the process water hot side of the cooler (13), and a part is connected to the external waste water pipeline through a regulating valve; the process water cooling side outlet of the cooler (13) is connected to the process water inlet pipeline on the top side of the water washing tower (6).

4. The device for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming according to claim 1, characterized in that: The working fluid of the steam jet pump (10) is the decompressed superheated steam from the heat recovery device I (3), and the ejection fluid is the high-temperature coke oven raw gas from the coke oven raw gas collecting pipe.

5. The device for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming according to claim 1, characterized in that: The steam jet pump (10) is composed of one ejector or a preset number of ejectors connected in series or in parallel.

6. The device for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming according to claim 1, characterized in that: A secondary cyclone separator (14) is provided between the outlet of the raw synthesis gas after indirect heat exchange of the heat recovery device I (3) and the inlet of the high-temperature filter (4).

7. A method for producing hydrogen by pressurizing high-temperature coke oven raw gas with direct steam reforming, comprising: Coke oven raw gas with a temperature of 550-800° C. from a coke oven raw gas collecting pipe enters the steam jet pump (10) from the injection fluid inlet of the steam jet pump (10), and after being drawn, mixed and pressurized by the working fluid superheated steam of the steam jet pump (10), enters the interior of the catalytic reforming furnace from the top side inlet of the reforming furnace (1). The pressurized superheated steam and the high-temperature raw gas are quickly mixed with the oxygen injected from the top of the reforming furnace and a high-temperature combustion reaction occurs, instantly causing the temperature in the reforming furnace to reach 1200-1500° C., and the carbon-containing organic matter in the coke oven raw gas undergoes a reforming reaction with the water vapor to generate a synthesis gas mainly composed of hydrogen and carbon monoxide. The boiler feed water from the boiler feed water pipeline with a pressure of 4.0~6.0Mpa first enters the shell side of the heat recovery device II (5) for indirect heat exchange and temperature rise. After the temperature rises to 170~210°C, it enters the steam drum (11) and forms an indirect heating and temperature rise system with the heat recovery device I (3) through the steam drum (11). After indirect heat exchange with the heat recovery device I (3), superheated steam with a pressure of 3.0~5.0Mpa and a temperature of 400~600°C is obtained. Part of the superheated steam is reduced in pressure by the pressure reducing valve and then enters the steam jet pump as the working fluid, and the rest of the superheated steam is sent out as by-product steam. The high-temperature raw synthesis gas from the side outlet of the bottom of the reforming furnace enters the primary cyclone separator (2), and a part of the carbonaceous solid fly ash particles entrained in the raw synthesis gas are separated by the primary cyclone separator (2); The high-temperature raw synthesis gas from the top outlet of the primary cyclone separator (2) enters the heat recovery device I (3), and is reduced in temperature to 350-500°C through indirect heat exchange with water / steam, and then enters the high-temperature filter (4); The 350-500°C raw synthesis gas after further dust removal from the high temperature filter enters the heat recovery device II, and is indirectly heat-exchanged with boiler feed water to reduce the temperature to 150-250°C, and then enters the water scrubber (6); The hot synthesis gas from the top of the water scrubber (6) enters the synthesis gas compressor for compression and transportation, and then enters the shift device. Under the action of the shift catalyst, the carbon monoxide and water vapor in the synthesis gas undergo a shift reaction to generate carbon dioxide and hydrogen, thereby obtaining a shift gas. The conversion gas from the conversion device enters the low-temperature methanol washing device to obtain hydrogen product, liquid carbon dioxide by-product and sulfur by-product.

8. The method for producing hydrogen by pressurized direct steam reforming of high-temperature coke oven raw gas according to claim 7, characterized in that: When the working fluid superheated steam of the steam jet pump (10) is in normal operation, it is the decompressed superheated steam from the heat recovery device I, with a temperature of 400-600° C. and a pressure of 0.6-4.0 MPa; the reaction pressure of the reforming furnace (1) is 0.1-1.0 MPa.

9. The method for producing hydrogen by pressurized direct steam reforming of high-temperature coke oven raw gas according to claim 7, characterized in that: The process water outlet at the bottom of the water washing tower (6) is transported to the cooler (13) through the circulation pump (12) and cooled to 100-150°C in the cooler (13).

10. The method for producing hydrogen by pressurized direct steam reforming of high-temperature coke oven raw gas according to claim 7, characterized in that: The outlet of the heat recovery device I enters the secondary cyclone separator (14) to further separate part of the carbonaceous solid fly ash particles entrained in the raw synthesis gas, and the top outlet of the secondary cyclone separator (14) enters the high-temperature filter (4).

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