Coke oven gas hydrogen extraction system

Abstract

The utility model belongs to the technical field of hydrogen extraction, and particularly relates to a coke oven gas hydrogen extraction system. The heater is communicated with the coalescence type filter through a pipeline; the membrane separation skid is communicated with the heater, and the membrane separation skid comprises a plurality of membrane separators which are connected in sequence. In the working process, hydrodesulfurization gas is filtered through the coalescence type filter, then enters the heater to be heated to high-temperature gas and enters the membrane separation skid to be separated, the membrane separation skid is composed of a plurality of sets of membrane separators, and after the hydrodesulfurization gas enters the membrane separators, under the action of the pressure difference between the inner side and the outer side of membrane filaments, the hydrodesulfurization gas enters the membrane separators. And fast gases such as hydrogen preferentially penetrate through the surfaces of the fibers and are diffused into the inner sides of the fibers, so that hydrogen-enriched high-concentration permeable gases are obtained on the inner sides of the fibers and are output from the membrane separator. Hydrogen with the purity of 91% can be extracted through the hydrogen extraction system, and the hydrogen is pressurized by the hydrogen compressor and sent to synthetic ammonia, so that the yield of liquid ammonia is greatly improved, and the unit consumption of gas is reduced.

Description

Technical Field

[0001] This application belongs to the technical field of hydrogen extraction, and particularly relates to a hydrogen extraction system for coke oven gas. Background Art

[0002] The polyimide membrane separation technology uses the gas after fine desulfurization in the process device. After hydrogen extraction by membrane separation, the hydrogen-rich gas is sent to the synthetic ammonia system as raw material gas through a hydrogen booster. The process flow of membrane separation hydrogen extraction can be divided into two basic processes. One is the heating pretreatment of coke oven gas after removing sulfur, ammonia, and naphthalene, and the other is the membrane separation process.

[0003] In the existing production process of synthetic ammonia, hydrogen is usually extracted from methanol purge gas to produce synthetic ammonia. Since the hydrogen content in methanol purge gas is only about 65%, it not only seriously affects the liquid ammonia production, but also cannot achieve the treatment effect on the gas recovery of the final system. Summary of the Invention

[0004] The embodiment of this application provides a hydrogen extraction system for coke oven gas. Through this hydrogen extraction system, hydrogen with a purity of 91% can be extracted. The hydrogen is pressurized by a hydrogen compressor and sent to synthetic ammonia, thus greatly increasing the liquid ammonia production and reducing the specific gas consumption.

[0005] A hydrogen extraction system for coke oven gas includes:

[0006] A coalescing filter;

[0007] A heater, which is connected to the coalescing filter through a pipeline;

[0008] A membrane separation skid, which is connected to the heater. The membrane separation skid includes a plurality of membrane separators connected in sequence.

[0009] For the hydrogen extraction system for coke oven gas according to other embodiments of the present utility model, a plurality of coalescing filters are provided, and each of the coalescing filters is arranged in parallel.

[0010] For the hydrogen extraction system for coke oven gas according to other embodiments of the present utility model, it further includes a pre-treatment system. The pre-treatment system includes a desulfurized coal gas pipeline, a hydrodesulfurized coal gas pipeline, and a heat exchange module. Both the desulfurized coal gas pipeline and the hydrodesulfurized coal gas pipeline are connected to the heat exchange module, and the hydrodesulfurized coal gas pipeline is connected to the coalescing filter.

[0011] For the hydrogen extraction system for coke oven gas according to other embodiments of the present utility model, the pre-treatment system further includes a deoxidation module, and the deoxidation module is arranged on the desulfurized coal gas pipeline.

[0012] For the hydrogen extraction system of coke oven gas according to some other embodiments of the present utility model, the pre-treatment system further includes a waste heat recovery module. The hydrodesulfurized coal gas pipeline is connected to the waste heat recovery module. One end of the waste heat recovery module is connected to a deoxidized water pipeline, and the other end is connected to a low-pressure steam pipeline.

[0013] For the hydrogen extraction system of coke oven gas according to some other embodiments of the present utility model, a water heater is installed on the hydrodesulfurized coal gas pipeline, and the water heater is connected to a cold desalted water system.

[0014] For the hydrogen extraction system of coke oven gas according to some other embodiments of the present utility model, a water cooler is installed on the hydrodesulfurized coal gas pipeline.

[0015] For the hydrogen extraction system of coke oven gas according to some other embodiments of the present utility model, a separator module is installed on the hydrodesulfurized coal gas pipeline. The separator module is used for dewaxing and deoiling the hydrodesulfurized coal gas in the hydrodesulfurized coal gas pipeline.

[0016] The hydrogen extraction system of coke oven gas in the embodiments of the present utility model has at least the following beneficial effects: During the working process, the hydrodesulfurized coal gas is filtered through a coalescing filter, then enters a heater to be heated to a high-temperature gas, and then enters a membrane separation skid for separation. The membrane separation skid is composed of multiple groups of membrane separators. After the hydrodesulfurized coal gas enters the membrane separator, under the pressure difference on both sides of the membrane filament, fast gases such as hydrogen preferentially penetrate through the surface of the fiber filament and diffuse into the inner side of the fiber filament. Thus, a high-concentration permeate gas enriched with hydrogen is obtained on the inner side of the fiber filament and output from the membrane separator. Through this hydrogen extraction system, hydrogen with a purity of 91% can be extracted. The hydrogen is pressurized by a hydrogen compressor and sent to synthetic ammonia, thereby greatly increasing the liquid ammonia production and reducing the unit gas consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a partial structural schematic diagram of the hydrogen extraction system of coke oven gas provided by an embodiment of the present application;

[0018] Figure 2 is a schematic diagram of the pre-treatment system of the hydrogen extraction system of coke oven gas provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In order to enable those skilled in the art to better understand the technical solutions in the present application, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0020] The following further describes the implementation manners of the present application in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0021] In the description of the embodiments of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the embodiments of the present application 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 a limitation to the embodiments of the present application. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0022] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "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 directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0023] In the embodiments of the present application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0024] The polyimide membrane separation technology uses the coal gas after fine desulfurization by the process device. After hydrogen is separated by the membrane, the hydrogen-rich gas is sent to the synthetic ammonia system as raw material gas through a hydrogen booster. The process flow of membrane separation for hydrogen production can be divided into two basic processes. One is the heating pretreatment of the coke oven gas after removing sulfur, ammonia, and naphthalene, and the other is the membrane separation process.

[0025] In the existing process of making synthetic ammonia, usually methanol purge gas is used to produce hydrogen for synthetic ammonia. Since the hydrogen content in the methanol purge gas is only about 65%, it not only seriously affects the liquid ammonia production, but also cannot achieve the treatment effect for the gas recovery in the final system.

[0026] SeeFigure 1 , Figure 2 , this application provides a hydrogen extraction system for coke oven gas, which includes a coalescing filter 1, a heater 2 and a membrane separation skid 3. The heater 2 is connected to the coalescing filter 1 through a pipeline, and the membrane separation skid 3 is connected to the heater 2. The membrane separation skid 3 includes a plurality of membrane separators connected in sequence.

[0027] During the working process, the hydrodesulfurized gas passes through the coalescing filter 1 for filtration, then enters the heater 2 to be heated into a high-temperature gas, and then enters the membrane separation skid 3 for separation. The membrane separation skid 3 consists of multiple groups of membrane separators. After the hydrodesulfurized gas enters the membrane separator, under the pressure difference on both sides of the membrane filament, fast gases such as hydrogen preferentially permeate through the surface of the fiber filament and diffuse into the inner side of the fiber filament, so that a high-concentration permeate gas enriched with hydrogen is obtained on the inner side of the fiber filament and output from the membrane separator. Through this hydrogen extraction system, hydrogen with a purity of 91% can be extracted. The hydrogen is pressurized by a hydrogen compressor and sent to synthetic ammonia, thus greatly increasing the output of liquid ammonia and reducing the gas consumption per unit volume.

[0028] In some embodiments, a plurality of coalescing filters 1 are provided, and the coalescing filters 1 are arranged in parallel. This can improve the filtration efficiency.

[0029] In the embodiment shown in this application, two coalescing filters 1 are provided. After the hydrodesulfurized gas comes in, it first divides into two paths and enters the two coalescing filters 1 respectively for filtration. The filtered hydrodesulfurized gas is collected and then enters the heater 2 for heat treatment.

[0030] In some embodiments, this application further includes a pre-treatment system. The pre-treatment system includes a desulfurized coal gas pipeline 4, a hydrodesulfurized coal gas pipeline 8 and a heat exchange module 5. Both the desulfurized coal gas pipeline 4 and the hydrodesulfurized coal gas pipeline 8 are connected to the heat exchange module 5, and the hydrodesulfurized coal gas pipeline 8 is connected to the coalescing filter 1.

[0031] The gas in the desulfurized coal gas pipeline 4 is a low-temperature gas and needs to be heated, while the gas in the hydrodesulfurized coal gas pipeline 8 is a high-temperature gas and needs to be cooled. In this application, the desulfurized coal gas pipeline 4, the hydrodesulfurized coal gas pipeline 8 and the heat exchange module 5 are connected together. When the high-temperature gas in the hydrodesulfurized coal gas pipeline 8 passes through the heat exchange module 5, it will transfer heat to the low-temperature gas in the desulfurized coal gas pipeline 4, so that the gas in the desulfurized coal gas pipeline 4 is heated, and at the same time, the gas in the hydrodesulfurized coal gas pipeline 8 is cooled, realizing energy utilization.

[0032] In this application, the heat exchange module 5 includes two heat exchangers 50 connected in sequence.

[0033] In some embodiments, the pre-treatment system further includes a deoxidation module 6, and the deoxidation module 6 is arranged on the desulfurized coal gas pipeline 4.

[0034] When the gas in the desulfurized gas pipeline 4 passes through the heat exchange module 5 and then enters the deoxidation module 6, the oxygen component in the gas is removed through the deoxidation module 6, facilitating the subsequent hydrogenation treatment of the desulfurized gas.

[0035] Specifically, the deoxidation module 6 includes a deoxidation tank.

[0036] In some embodiments, to recover the heat in the hydrodesulfurized gas, the pre-treatment system further includes a waste heat recovery module 9. The hydrodesulfurized gas pipeline 8 is connected to the waste heat recovery module 9. One end of the waste heat recovery module 9 is connected to the deoxidized water pipeline, and the other end is connected to the low-pressure steam pipeline.

[0037] The deoxidized water pipeline supplies deoxidized water to the preheating recovery module. The high-temperature hydrodesulfurized gas heats the deoxidized water into steam after passing through the waste heat recovery module 9, and the steam enters the low-pressure steam pipeline for other heating processes. This can not only recover heat and by-product steam, but also better control the temperature of each tank in the fine desulfurization within the specified range, improving the membrane hydrogen production volume and hydrogen production rate.

[0038] In some embodiments, a water heater 10 is installed on the hydrodesulfurized gas pipeline 8, and the water heater 10 is connected to the cold demineralized water system.

[0039] Cold demineralized water is introduced into the water heater 10. When the hydrodesulfurized gas passes through the water heater 10, it will heat the cold demineralized water inside the water heater 10. This not only cools the hydrodesulfurized gas but also realizes heat utilization.

[0040] In some embodiments, a water cooler 11 is installed on the hydrodesulfurized gas pipeline 8 to further cool the hydrodesulfurized gas.

[0041] Specifically, the water cooler 11 is arranged in parallel with the water heater 10. When the hydrodesulfurized gas passing through the water heater 10 still needs to be cooled, the valves at both ends of the water cooler 11 can be controlled to open, so that the hydrodesulfurized gas enters the water cooler 11 for further cooling.

[0042] In some embodiments, a separator module 12 is installed on the hydrodesulfurized gas pipeline 8. The separator module 12 is used for naphthalene and oil removal treatment of the hydrodesulfurized gas in the hydrodesulfurized gas pipeline 8. After the hydrodesulfurized gas passes through the separator module 12, the separator module 12 can extract hydrogen from the coke oven gas and recover and utilize the rich methane gas. Under the condition of stable production load, through the optimization and adjustment of production technology, the liquid ammonia production can be increased.

[0043] Specifically, in the embodiments shown in the present application, the separator module 12 includes two V61202 type composite high-efficiency separators. The hydrodesulfurized coal gas in the hydrodesulfurized coal gas pipeline 8 will enter the two composite high-efficiency separators respectively, be subjected to naphthalene and oil removal treatment, and then converge, and then enter the coalescing filter 1.

[0044] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

Claims

1. A hydrogen extraction system for coke oven gas, characterized in that, Comprising: A coalescing filter; A heater, which is communicated with the coalescing filter through a pipeline; A membrane separation skid, which is communicated with the heater, and the membrane separation skid includes a plurality of membrane separators connected in sequence.

2. The hydrogen extraction system for coke oven gas according to claim 1, wherein A plurality of the coalescing filters are provided, and each of the coalescing filters is arranged in parallel.

3. The hydrogen extraction system for coke oven gas according to claim 1, wherein It further includes a pre-treatment system, the pre-treatment system includes a desulfurized coal gas pipeline, a hydrodesulfurized coal gas pipeline and a heat exchange module, both the desulfurized coal gas pipeline and the hydrodesulfurized coal gas pipeline are connected to the heat exchange module, and the hydrodesulfurized coal gas pipeline is communicated with the coalescing filter.

4. The hydrogen extraction system for coke oven gas according to claim 3, wherein The pre-treatment system further includes a deoxidation module, and the deoxidation module is arranged on the desulfurized coal gas pipeline.

5. The hydrogen extraction system for coke oven gas according to claim 3, characterized in that, The pre-treatment system further includes a waste heat recovery module, the hydrodesulfurized coal gas pipeline is connected to the waste heat recovery module, one end of the waste heat recovery module is connected to a deoxygenated water pipeline, and the other end is connected to a low-pressure steam pipeline.

6. The hydrogen production system for coke oven gas according to claim 3, characterized in that, A water heater is installed on the hydrodesulfurized coal gas pipeline, and the water heater is connected to a cold desalted water system.

7. The hydrogen extraction system for coke oven gas according to claim 3, characterized in that, A water cooler is installed on the hydrodesulfurized coal gas pipeline.

8. The hydrogen extraction system for coke oven gas according to claim 3, characterized in that, A separator module is installed on the hydrodesulfurized coal gas pipeline, and the separator module is used for dewaxing and deoiling the hydrodesulfurized coal gas in the hydrodesulfurized coal gas pipeline.

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