A system and method for removing organic sulfur from coal gas

Abstract

The present invention provides a system and method for removing organic sulfur from coal gas. The system includes at least two desulfurization towers, an incinerator, a regenerated gas blower and an air blower; in the flue gas discharge chamber of the incinerator, there are at least arranged a gas heating device, a steam generating device and an air preheating device; the inlets of the desulfurization towers are respectively connected to the main coal gas inlet pipe through coal gas inlet branch pipes in a switchable manner; the coal gas inlet branch pipes are respectively connected to the regenerated desorption gas branch pipes, and these branch pipes are respectively connected to the main regenerated desorption gas pipe in a switchable manner; the outlets of the desulfurization towers are respectively connected to the main clean coal gas outlet pipe through clean coal gas outlet branch pipes in a switchable manner; the clean coal gas outlet branch pipes are also respectively connected to the regenerated gas inlet branch pipes, and these branch pipes are respectively connected to the main regenerated gas inlet pipe in a switchable manner; the main clean coal gas outlet pipe is connected to the inlet of the regenerated gas blower, and its outlet is respectively connected to the main regenerated gas inlet pipe and the inlet of the gas heating device through pipelines in a switchable manner; the outlet of the gas heating device is connected to the main regenerated gas inlet pipe through a pipeline in a switchable manner.

Description

Technical Field

[0001] The present invention relates to a system and method for removing organic sulfur from coal gas, belonging to the technical field of coal gas desulfurization. Background Art

[0002] The sulfur in coal gas (including blast furnace gas, coke oven gas, producer gas, etc.) is mainly divided into inorganic sulfur (mainly hydrogen sulfide) and organic sulfur such as COS, CS2, thioether, thiol, and thiophene. Inorganic sulfur (mainly H2S) is easy to remove, while organic sulfur is extremely difficult to remove. After the purification of coal gas, due to the large amount of organic sulfur contained, the sulfur content in the exhaust gas discharged by subsequent users exceeds the standard. With the increasingly strict environmental protection requirements, it is very necessary to remove organic sulfur from coal gas. Generally, the methods for removing organic sulfur include adsorption method, pyrolysis method, hydrolysis method, and hydroconversion method. The adsorption method is divided into chemical adsorption and physical adsorption. The commonly used desulfurizer is activated carbon or molecular sieve. However, activated carbon is volatile at medium and high temperatures and has strong water absorption. It is only suitable for low-temperature desulfurization and is not suitable for coal gas with high water content; the pyrolysis method has low efficiency and is difficult to be popularized and applied; the hydrolysis method and the hydroconversion method, when applied to the removal of organic sulfur from coal gas, have the disadvantages of large scale and high investment. With the increasing attention to the treatment of organic sulfur, it is imperative to develop a suitable method for removing organic sulfur from coal gas.

[0003] Chinese Patent CN 108102728A discloses a method for removing organic sulfur from coke oven gas, which includes the following steps: a. The coke oven gas coming out of the coke oven enters the crude benzene removal unit, and after crude benzene removal, a stream Ⅰ is formed; b. The stream Ⅰ enters the crude desulfurization unit, and after crude desulfurization, a stream Ⅱ is formed; c. The stream Ⅱ enters the comprehensive purification tower. The comprehensive purification tower contains a molecular sieve adsorbent, and at the same time removes aromatics and organic sulfides in the coal gas to form a stream Ⅲ; e. The stream Ⅲ is compressed by a compressor and then sent to a gas turbine for combustion power generation, and then the tail gas after the combustion of the gas turbine is discharged. In this invention, the final tail gas can meet the emission standards, but the adsorbed organic sulfur is only transferred and not treated, which will cause secondary pollution.

[0004] Chinese Patent CN 101323799A discloses a temperature swing adsorption process for dry purification of coke oven gas, which processes the raw coke oven gas through an impurity removal system and an impurity recovery and treatment system to achieve the purpose of removing impurities and purifying the coke oven gas. After the coke oven gas is purified by this invention, solid impurities, liquid impurities, and gases are separated by a cooling method, and the organic sulfur is not treated. To sum up, there is no system and method in the current prior art that has small investment, simple process, and is suitable for removing organic sulfur from coal gas.

[0005] Therefore, providing a new type of incinerator, a system and method for removing organic sulfur from coal gas has become an urgent technical problem to be solved in this field. Summary of the Invention

[0006] To solve the above-mentioned disadvantages and deficiencies, the purpose of the present invention is to provide a system and method for removing organic sulfur from coal gas. The system and method provided by the present invention adopt a method of coupling hydrophobic molecular sieve adsorption, regenerated gas incineration, and high-temperature flue gas heat recovery to remove organic sulfur from coal gas. It is a practical technical route that can achieve desulfurization and fine desulfurization of coal gas and then achieve up-to-standard discharge. It does not require pre-converting organic sulfur in large-scale coal gas into inorganic sulfur, only needs to treat a small amount of regenerated gas, and has the advantages of low investment, simple process, high purification efficiency, high organic sulfur conversion rate, no secondary pollution, high thermal efficiency, and high resource recovery utilization rate.

[0007] To achieve the above purpose, on the one hand, the present invention provides a system for removing organic sulfur from coal gas, wherein the system for removing organic sulfur from coal gas includes: at least two desulfurization towers, an incinerator, a regenerated gas blower, and an air blower;

[0008] The incinerator includes a main combustion chamber and a flue gas discharge chamber, and at least a gas heating device, a steam generating device, and an air preheating device are arranged in the flue gas discharge chamber;

[0009] The air inlets of the desulfurization towers are respectively connected to the main coal gas inlet pipe through coal gas inlet branch pipes in a switchable manner; the coal gas inlet branch pipes are also respectively connected to regenerated desorption gas branch pipes, and the regenerated desorption gas branch pipes are respectively connected to the main regenerated desorption gas pipe in a switchable manner;

[0010] The gas outlets of the desulfurization towers are respectively connected to the main clean coal gas outlet pipe through clean coal gas outlet branch pipes in a switchable manner; the clean coal gas outlet branch pipes are also respectively connected to regenerated gas inlet branch pipes, and the regenerated gas inlet branch pipes are respectively connected to the main regenerated gas inlet pipe in a switchable manner;

[0011] The main clean coal gas outlet pipe is connected to the inlet of the regenerated gas blower, and the outlet of the regenerated gas blower is respectively connected to the inlet of the main regenerated gas inlet pipe and the inlet of the gas heating device through pipelines in a switchable manner; the outlet of the gas heating device is connected to the main regenerated gas inlet pipe through a pipeline in a switchable manner;

[0012] The outlet pipeline of the air blower is connected to the inlet of the main combustion chamber of the incinerator after passing through the air preheating device;

[0013] The main regenerated desorption gas pipe is also connected to the inlet of the main combustion chamber of the incinerator.

[0014] According to a specific implementation plan of the present invention, in the system for removing organic sulfur from coal gas, the desulfurization towers used are conventional desulfurization towers in the art, which are provided with air inlets, gas outlets, packing layers, packing filling holes, discharge holes, manholes, condensate discharge outlets, etc.

[0015] According to a specific embodiment of the present invention, in the system for removing organic sulfur from coal gas, the regenerated desorbed gas and the preheated air are mixed in the main combustion chamber of the incinerator and burn sufficiently.

[0016] According to a specific embodiment of the present invention, in the system for removing organic sulfur from coal gas, the incinerator is respectively provided with a main combustion chamber and a flue gas discharge chamber, and a plurality of heat recovery devices are also provided in the flue gas discharge chamber for recovering the waste heat of the incinerator to generate steam, preheat air, etc.; in addition, by using the heat recovery device, it is also possible to realize the energy grading recovery and utilization of the flue gas containing a high concentration of SO2 according to the reduction of the temperature gradient.

[0017] According to a specific embodiment of the present invention, preferably, the system further includes a steam drum, the liquid inlet of the steam drum is connected to the deaerated water pipeline, the liquid outlet of the steam drum is connected to the steam inlet of the steam drum via a pipeline through a steam generating device, and the steam outlet of the steam drum is connected to the regenerated gas blower via a pipeline.

[0018] In a specific embodiment of the present invention, deaerated water is provided to the steam generating device through the steam drum, the deaerated water is heated by the steam generating device to generate steam, the generated steam is sent into the steam drum for steam-water separation to obtain steam after water removal, and the steam after water removal is sent into the regenerated gas blower to drive the regenerated gas blower, which can save power consumption; the water vapor can also be supplied to other users, saving costs.

[0019] Wherein, the steam generating device is a conventional device used in the art, and in a specific embodiment of the present invention, it can be a heat exchanger;

[0020] The regenerated gas blower is also a conventional device used in the art, and it can be driven by electricity. In the present invention, it is preferably driven in a form combining electricity and steam.

[0021] According to a specific embodiment of the present invention, in the system for removing organic sulfur from coal gas, preferably, the main pipe of the clean coal gas outlet is connected to the inlet of the regenerated gas blower, and the outlet of the regenerated gas blower is connected to the main pipe of the regenerated gas inlet through a pipeline in a switchable manner;

[0022] The steam outlet of the steam drum is also connected to the main pipe of the regenerated gas inlet through a pipeline in a switchable manner;

[0023] The main pipe of the regenerated desorbed gas is connected to the inlet of the main combustion chamber of the incinerator via a condensation device.

[0024] In a specific embodiment of the present invention, the main pipe of the clean coal gas outlet is connected to the inlet of the regenerated gas blower, and the outlet of the regenerated gas blower is connected to the main pipe of the regenerated gas inlet through a pipeline via a cut-off valve;

[0025] The steam outlet of the steam drum is also connected to the main inlet pipe of the regenerated gas through a pipeline via a cut-off valve;

[0026] The main pipe of the regenerated desorbed gas is connected to the inlet of the main combustion chamber of the incinerator through a condensation device.

[0027] According to a specific embodiment of the present invention, in the system for removing organic sulfur from coal gas, preferably, the outlet of the regenerated gas blower is also connected to the inlet of the gas heating device through a pipeline in a switchable manner; the outlet of the gas heating device is connected to the inlet of the main combustion chamber of the incinerator through a pipeline.

[0028] In a specific embodiment of the present invention, the outlet of the regenerated gas blower is also connected to the inlet of the gas heating device through a pipeline via a cut-off valve; the outlet of this gas heating device is connected to the inlet of the main combustion chamber of the incinerator through a pipeline.

[0029] According to a specific embodiment of the present invention, in the system for removing organic sulfur from coal gas, preferably, cut-off valves are provided on the coal gas inlet branch pipe, the regenerated desorbed gas branch pipe, the clean coal gas outlet branch pipe, and the regenerated gas inlet branch pipe;

[0030] The pipeline connecting the outlet of the regenerated gas blower to the main inlet pipe of the regenerated gas is provided with a cut-off valve, and the pipeline connecting the outlet of the regenerated gas blower to the inlet of the gas heating device is provided with a cut-off valve;

[0031] The pipeline connecting the outlet of the gas heating device to the main inlet pipe of the regenerated gas is provided with a cut-off valve.

[0032] According to a specific embodiment of the present invention, in the system for removing organic sulfur from coal gas, preferably, the packing used in the packing layer of the desulfurization tower is a hydrophobic molecular sieve material, and the hydrophobic molecular sieve material contains a catalyst for converting organic sulfur into inorganic sulfur; this hydrophobic molecular sieve material has an adsorption performance in the temperature range of 20°C - 120°C, undergoes desorption and regeneration in the temperature range of 180°C - 400°C, and can convert organic sulfur into inorganic sulfur during regeneration.

[0033] Among them, the packing used in the present invention is a new type of hydrophobic molecular sieve material, which is less affected by the water content in the coal gas, has high adsorption selectivity and efficiency, and has the functions of low-temperature adsorption, high-temperature desorption, and catalytic conversion of organic sulfur into inorganic sulfur;

[0034] The service life of this new type of hydrophobic molecular sieve material can reach 5 - 10 years, can be regenerated repeatedly, is resistant to high temperatures, and its structure does not change during long-term use at a temperature of 800°C.

[0035] According to the specific embodiments of the present invention, the hydrophobic molecular sieve material is a material containing at least one element among elements such as magnesium, calcium, strontium, yttrium, lanthanum, cerium, europium, iron, cobalt, nickel, copper, silver, zinc, etc.; specifically, the hydrophobic molecular sieve material is selected from at least one of X-type molecular sieve, Y-type molecular sieve, A-type molecular sieve, ZSM-type molecular sieve, mordenite, β-type molecular sieve, MCM-type molecular sieve, SAPO-type molecular sieve;

[0036] The catalyst for converting organic sulfur into inorganic sulfur includes at least one of iron-cobalt-manganese-molybdenum-nickel-based catalysts, CO-K-Al2O3, and ZrO2 / TiO2-based catalysts; and in actual implementation, those skilled in the art can reasonably set the dosage of the catalyst according to on-site operation needs. For example, in a specific embodiment of the present invention, the space velocity of the desulfurization tower can be 500-1000 h -1 , and the coal gas flow rate can be 0.5-1.0 m / s.

[0037] According to the specific embodiments of the present invention, in the system for removing organic sulfur from coal gas, since the used desulfurization tower needs to adopt different operations at different temperatures, preferably, a temperature and pressure measuring device is provided in the packing layer of the desulfurization tower.

[0038] According to the specific embodiments of the present invention, in the system for removing organic sulfur from coal gas, preferably, a blow-off pipe is provided on the clean coal gas outlet branch pipe.

[0039] Among them, when the system of the present invention stops operating, it is necessary to purge the system with steam or inert gas to drive out the coal gas therein. At this time, the expelled coal gas needs to be discharged from the blow-off pipe to ensure the safety of the overhauled system.

[0040] According to the specific embodiments of the present invention, in the system for removing organic sulfur from coal gas, the used cut-off valve can be a gate valve, a butterfly valve, a blind plate valve, etc., and the starting forms of the cut-off valve include one or a combination of manual, pneumatic, and electric forms.

[0041] According to the specific embodiments of the present invention, in the system for removing organic sulfur from coal gas, when the temperature of the used pipeline is higher than 50 °C, it is necessary to insulate it. When insulating, the insulation layer can adopt composite silicate materials, and a galvanized aluminum sheet is coated outside the insulation layer.

[0042] On the other hand, the present invention also provides a method for removing organic sulfur from coal gas. Among them, the method for removing organic sulfur from coal gas uses the above-mentioned system for removing organic sulfur from coal gas, and it includes the following steps:

[0043] (1) The coal gas after rough purification enters the desulfurization tower to adsorb the inorganic sulfur and organic sulfur in the coal gas to obtain clean coal gas;

[0044] (2) After the adsorption in the desulfurization tower reaches the preset level, the desulfurization tower is regenerated with the pressurized and heated clean gas as the regeneration gas. After the desulfurization tower is heated up to the set temperature (i.e., the temperature of the pressurized and heated clean gas, 180°C - 400°C) by the regeneration gas, heat preservation is carried out. During the heat preservation process, the adsorbed inorganic sulfur and organic sulfur are desorbed, and the organic sulfur is catalytically converted into inorganic sulfur; the pressurized and heated clean gas is cut off, and the desulfurization tower is cooled with the unheated clean gas to complete the regeneration process of the desulfurization tower;

[0045] (3) The regeneration desorption gas obtained in step (2) is mixed with the preheated air and burned in the incinerator to convert the inorganic sulfur and organic sulfur in the regeneration desorption gas into SO2;

[0046] (4) The flue gas obtained in step (3) is subjected to hierarchical heat recovery, and after the flue gas temperature is reduced to the target temperature, it is sent to the subsequent treatment section.

[0047] According to the specific implementation of the present invention, in the method for removing organic sulfur from coal gas, preferably, in step (1), the temperature range of the coarsely purified coal gas is 20°C - 120°C, the pressure is less than 0.1 MPa, the total sulfur ≥ 100 mg / m 3 , the dust content < 10 mg / m 3 ;

[0048] The total sulfur of the clean gas < 20 mg / m 3 .

[0049] Among them, the coarsely purified coal gas includes blast furnace gas, coke oven gas, producer gas, etc.

[0050] According to the specific implementation of the present invention, in the method for removing organic sulfur from coal gas, preferably, in step (1), 1 desulfurization tower is reserved for standby, and the rest of the desulfurization towers work for adsorption.

[0051] According to the specific implementation of the present invention, in the method for removing organic sulfur from coal gas, preferably, in step (2), after the adsorption in the desulfurization tower reaches the preset level, the desulfurization tower is regenerated with water vapor as the regeneration gas. After the desulfurization tower is heated up to the set temperature by the regeneration gas, heat preservation is carried out. During the heat preservation process, the adsorbed inorganic sulfur and organic sulfur are desorbed, and the organic sulfur is catalytically converted into inorganic sulfur;

[0052] The obtained regeneration desorption gas is subjected to condensation separation, and then the gas containing inorganic sulfur and organic sulfur obtained after condensation separation is mixed with the preheated air and burned in the incinerator;

[0053] The temperature of the water vapor is greater than 180°C, and the pressure range is 0.4 MPa - 0.6 MPa.

[0054] According to a specific embodiment of the present invention, when using water vapor as the regeneration gas to regenerate the desulfurization tower, the desulfurization tower is cooled by the clean gas. After the cooling is completed, the used clean gas can be sent to other desulfurization towers for adsorption desulfurization treatment together with the raw gas or sent to the incinerator for combustion.

[0055] According to a specific embodiment of the present invention, when using water vapor as the regeneration gas to regenerate the desulfurization tower, the regeneration process specifically includes: First, the water vapor as the regeneration gas can desorb the sulfide in the desulfurization tower. After that, the obtained regenerated desorbed gas needs to be condensed and separated. The gas containing high-concentration inorganic sulfur and organic sulfur such as hydrogen sulfide separated is sent to the incinerator for incineration; then the desulfurization tower is cooled with unheated clean gas.

[0056] In addition, in this regeneration process, clean gas can be supplemented to the incinerator for auxiliary combustion according to different situations. After combustion, the flue gas containing SO2 is sent to the subsequent section for treatment and then discharged up to standard.

[0057] Among them, the water vapor used as the regeneration gas comes from the flue gas discharge chamber (steam generation device) of the incinerator, and there is no need to input steam from the outside, with high energy utilization rate.

[0058] According to a specific embodiment of the present invention, in the method for removing organic sulfur in the gas, when the temperature of the heated clean gas is lower than 180°C, the desorption effect is poor. When its temperature is higher than 400°C, the adsorption efficiency can be improved, but the energy consumption is high at this time; in addition, the system provided by the present invention operates under normal pressure, the gas pressure is lower than 0.1 MPa, and the pressure loss of this system is less than 3 KPa. To increase the pressure difference, additional energy consumption is required. Therefore, the pressure of the regeneration gas does not need to be too high.

[0059] Therefore, preferably, in step (2), the temperature range of the heated clean gas is 180°C - 400°C, and the pressure difference range of the clean gas before and after pressurization is 4 KPa - 100 KPa.

[0060] According to a specific embodiment of the present invention, in the method for removing organic sulfur in the gas, preferably, in step (2), the heat preservation time range is 24 h - 48 h.

[0061] According to a specific embodiment of the present invention, in the method for removing organic sulfur in the gas, in step (2), the regeneration process of any desulfurization tower generally takes 1 - 5 days, preferably 3 days.

[0062] According to a specific embodiment of the present invention, in the method for removing organic sulfur in the gas, in step (2), the cooling is to cool to the operating temperature of the desulfurization tower, that is, to cool to 20°C - 120°C.

[0063] According to a specific embodiment of the present invention, in the method for removing organic sulfur from coal gas, preferably, in step (3), the temperature range of the combustion is 800°C - 1200°C.

[0064] According to a specific embodiment of the present invention, in the method for removing organic sulfur from coal gas, if the flue gas temperature in the pipeline is too high, it is not conducive to the pipeline for transporting it. Therefore, preferably, in step (4), the flue gas temperature is reduced to 200°C - 500°C.

[0065] According to a specific embodiment of the present invention, in the method for removing organic sulfur from coal gas, the pressure difference between the inlet and outlet of the desulfurization tower (which refers to the pressure difference between the inlet of the coal gas after rough purification in the desulfurization tower and the outlet of the clean coal gas during the adsorption process) is less than 3 KPa.

[0066] Among them, in the present invention, the pressure difference between the inlet and outlet of the desulfurization tower is less than 3 KPa. Correspondingly, the inlet coal gas pressure of the desulfurization tower is relatively low, and the system energy consumption is low.

[0067] According to a specific embodiment of the present invention, in a specific embodiment of the present invention, when the first desulfurization tower is regenerated, it is necessary to ensure that the second desulfurization tower and the third desulfurization tower are in the adsorption state; when the second desulfurization tower is regenerated, it is necessary to ensure that the first desulfurization tower and the third desulfurization tower are in the adsorption state.

[0068] According to a specific embodiment of the present invention, in the method for removing organic sulfur from coal gas, in step (4), the subsequent treatment section can use a traditional process to remove SO2. For example, a conventional sulfuric acid production process in the art can be used to recover and utilize sulfur from the flue gas containing a relatively high concentration of SO2 to make the flue gas meet the discharge standards.

[0069] The method for removing organic sulfur from coal gas provided by the present invention passes a large volume of coal gas through a desulfurization tower filled with a new type of hydrophobic molecular sieve material to adsorb and remove inorganic sulfur and organic sulfur such as hydrogen sulfide therein. Then, a small volume of clean coal gas heated in an incinerator is used as the regeneration gas to regenerate the desulfurization tower. During regeneration, organic sulfur is converted into inorganic sulfur, and then the small amount of regenerated desorbed gas containing a relatively high concentration of hydrogen sulfide and unreacted organic sulfur is sent to the incinerator for combustion to convert it into flue gas containing SO2. After the heat of the flue gas is recovered in stages, it is sent to the subsequent section for treatment to meet the discharge standards.

[0070] The system and method for removing organic sulfur from coal gas provided by the present invention can achieve the following beneficial technical effects:

[0071] The present invention uses clean coal gas or steam for regeneration, without the need for external resources and with low energy consumption; and the amount of the regeneration gas is small, the sulfur concentration is high, and the scale of the equipment used for subsequent treatment of the regeneration gas is small, with low investment;

[0072] The present invention sends the regenerated gas containing high-concentration sulfur into an incinerator for incineration to convert sulfur into SO2. Subsequently, the flue gas treatment technology for the flue gas containing SO2 is simple, the flue gas can meet the discharge standards, the sulfur resources are recycled, energy is saved, and there is no secondary pollution.

[0073] In summary, the technical solution provided by the present invention does not require pre-converting the organic sulfur in a large-scale coal gas into inorganic sulfur. Only a small amount of regenerated gas needs to be treated. It has the advantages of low investment, simple process, high purification efficiency, high conversion rate of organic sulfur, no secondary pollution, high thermal efficiency, and high resource recovery and utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0075] Figure 1 It is a schematic structural diagram of the system for removing organic sulfur from coal gas in Embodiment 1 of the present invention.

[0076] Figure 2 It is a schematic structural diagram of the system for removing organic sulfur from coal gas in Embodiment 2 of the present invention.

[0077] Main reference numeral descriptions:

[0078] 1—Main coal gas inlet pipe;

[0079] 2—Main clean coal gas outlet pipe;

[0080] 3—Main regenerated gas inlet pipe;

[0081] 4—Main regenerative desorbed gas pipe;

[0082] 5—First desulfurization tower;

[0083] 6—Second desulfurization tower;

[0084] 7—Third desulfurization tower;

[0085] 8—Incinerator;

[0086] 9—Drum;

[0087] 10—Regenerated gas blower;

[0088] 11—Air blower;

[0089] 12—Steam generating device;

[0090] 13—Gas heating device;

[0091] 14 - Air preheating device;

[0092] 15 - Condensation device;

[0093] V1 - V17 - The first to the seventeenth shut-off valves. Detailed implementation manners

[0094] For a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the following detailed description of the technical solution of the present invention is provided in conjunction with the following specific embodiments, but it should not be construed as a limitation on the implementable scope of the present invention.

[0095] Embodiment 1

[0096] This embodiment provides a system for removing organic sulfur from coal gas. Among them, the structural schematic diagram of the system for removing organic sulfur from coal gas is as Figure 1 shown. It can be seen from Figure 1 that this system includes:

[0097] Three desulfurization towers (in the form of 2 in use and 1 standby), namely the first desulfurization tower 5, the second desulfurization tower 6, the third desulfurization tower 7, an incinerator 8, a regeneration gas blower 10, and an air blower 11;

[0098] The incinerator 8 includes a main combustion chamber and a flue gas discharge chamber. A gas heating device 13, a steam generation device 12, and an air preheating device 14 are arranged in the flue gas discharge chamber;

[0099] The intake ports of the first desulfurization tower 5, the second desulfurization tower 6, and the third desulfurization tower 7 are respectively connected to the coal gas intake main pipe 1 through coal gas intake branch pipes. Shut-off valves (the first shut-off valve V1, the third shut-off valve V3, and the fifth shut-off valve V5 in sequence) are arranged on each of these coal gas intake branch pipes; Each of the coal gas intake branch pipes is also respectively connected to a regeneration desorption gas branch pipe, and each of these regeneration desorption gas branch pipes is connected to the regeneration desorption gas main pipe 4. Shut-off valves (the second shut-off valve V2, the fourth shut-off valve V4, and the sixth shut-off valve V6 in sequence) are arranged on each of these regeneration desorption gas branch pipes;

[0100] The outlet ports of the first desulfurization tower 5, the second desulfurization tower 6, and the third desulfurization tower 7 are respectively connected to the clean coal gas outlet main pipe 2 through clean coal gas outlet branch pipes. Shut-off valves (the seventh shut-off valve V7, the ninth shut-off valve V9, and the eleventh shut-off valve V11 in sequence) are arranged on each of these clean coal gas outlet branch pipes; Each of the clean coal gas outlet branch pipes is also respectively connected to a regeneration gas intake branch pipe, and each of these regeneration gas intake branch pipes is connected to the regeneration gas intake main pipe 3. Shut-off valves (the eighth shut-off valve V8, the tenth shut-off valve V10, and the twelfth shut-off valve V12 in sequence) are arranged on each of these regeneration gas intake branch pipes;

[0101] The main outlet pipe 2 of the clean gas is connected to the inlet of the regeneration gas blower 10. The outlet of the regeneration gas blower 10 is connected to the main inlet pipe 3 of the regeneration gas and the inlet of the gas heating device 13 through pipelines via the fourteenth cut-off valve V14 and the sixteenth cut-off valve V16 respectively; the outlet of the gas heating device 13 is connected to the main inlet pipe 3 of the regeneration gas through a pipeline via the thirteenth cut-off valve V13;

[0102] The outlet pipeline of the air blower 11 is connected to the inlet of the main combustion chamber of the incinerator 8 after being preheated by the air preheating device 14;

[0103] The main pipe 4 of the regenerative desorption gas is also connected to the inlet of the main combustion chamber of the incinerator 8.

[0104] In this embodiment, the system further includes a steam drum 9. The liquid inlet of the steam drum 9 is connected to the deaerated water pipeline. The liquid outlet of the steam drum 9 is connected to the steam inlet of the steam drum through a pipeline via the steam generating device 12. The steam outlet of the steam drum is connected to the regeneration gas blower 10 through a pipeline.

[0105] In this embodiment, the fillers used in the packing layers of the first desulfurization tower 5, the second desulfurization tower 6, and the third desulfurization tower 7 are all copper-modified ZSM-5 molecular sieve materials. The silica-alumina ratio of the molecular sieve material is 150, and it contains a cobalt-molybdenum-nickel series catalyst; the space velocity of the desulfurization tower is 500 h -1 , and the gas flow velocity is 0.7 m / s.

[0106] In this embodiment, temperature and pressure measuring devices are also provided in the packing layers of the first desulfurization tower 5, the second desulfurization tower 6, and the third desulfurization tower 7.

[0107] In this embodiment, a blow-off pipe is also provided on the outlet branch pipe of the clean gas.

[0108] Embodiment 2

[0109] This embodiment provides a system for removing organic sulfur from coal gas. Among them, the structural schematic diagram of the system for removing organic sulfur from coal gas is as shown in Figure 2 shown. It can be seen from Figure 2 that this system includes:

[0110] Three desulfurization towers (in the form of 2 in use and 1 in standby), namely the first desulfurization tower 5, the second desulfurization tower 6, the third desulfurization tower 7, the incinerator 8, the regeneration gas blower 10, and the air blower 11;

[0111] The incinerator 8 includes a main combustion chamber and a flue gas emission chamber. A gas heating device, a steam generating device 12, and an air preheating device are arranged in the flue gas emission chamber;

[0112] The inlet ports of the first desulfurization tower 5, the second desulfurization tower 6, and the third desulfurization tower 7 are respectively connected to the main gas inlet pipe 1 through gas inlet branch pipes, and cut-off valves (the first cut-off valve V1, the third cut-off valve V3, and the fifth cut-off valve V5 in sequence) are provided on each of these gas inlet branch pipes; each of the gas inlet branch pipes is also connected to a regeneration desorption gas branch pipe, and these regeneration desorption gas branch pipes are respectively connected to the main regeneration desorption gas pipe 4, and cut-off valves (the second cut-off valve V2, the fourth cut-off valve V4, and the sixth cut-off valve V6 in sequence) are provided on each of these regeneration desorption gas branch pipes;

[0113] The outlet ports of the first desulfurization tower 5, the second desulfurization tower 6, and the third desulfurization tower 7 are respectively connected to the main clean gas outlet pipe 2 through clean gas outlet branch pipes, and cut-off valves (the seventh cut-off valve V7, the ninth cut-off valve V9, and the eleventh cut-off valve V11 in sequence) are provided on each of these clean gas outlet branch pipes; each of the clean gas outlet branch pipes is also connected to a regeneration gas inlet branch pipe, and these regeneration gas inlet branch pipes are respectively connected to the main regeneration gas inlet pipe 3, and cut-off valves (the eighth cut-off valve V8, the tenth cut-off valve V10, and the twelfth cut-off valve V12 in sequence) are provided on each of these regeneration gas inlet branch pipes;

[0114] The main clean gas outlet pipe 2 is connected to the inlet of the regeneration gas blower 10, and the outlet of the regeneration gas blower 10 is connected to the main regeneration gas inlet pipe 3 and the inlet of the gas heating device 13 through pipelines via the fourteenth cut-off valve V14 and the sixteenth cut-off valve V16 respectively; the outlet of the gas heating device 13 is connected to the inlet of the main combustion chamber of the incinerator 8 through a pipeline via the thirteenth cut-off valve V13;

[0115] The outlet pipeline of the air blower 11 is connected to the inlet of the main combustion chamber of the incinerator 8 after being preheated by the air preheating device 14;

[0116] The main regeneration desorption gas pipe 4 is also connected to the inlet of the main combustion chamber of the incinerator 8.

[0117] In this embodiment, the system further includes a steam drum 9. The liquid inlet of the steam drum 9 is connected to the deaerated water pipeline, the liquid outlet of the steam drum 9 is connected to the steam inlet of the steam drum through a pipeline via the steam generating device 12, and the steam outlet of the steam drum is connected to the regeneration gas blower 10 through a pipeline;

[0118] The steam outlet of the steam drum 9 is also connected to the main regeneration gas inlet pipe 3 through a pipeline via the cut-off valve V17;

[0119] The main regeneration desorption gas pipe 4 is connected to the inlet of the main combustion chamber of the incinerator 8 through the condensation device 15.

[0120] In this embodiment, the packing materials used in the packing layers of the first desulfurization tower 5, the second desulfurization tower 6, and the third desulfurization tower 7 are all copper-modified ZSM-5 molecular sieve materials. The silicon-aluminum ratio of this molecular sieve material is 150, and it contains a cobalt-molybdenum-nickel-based catalyst. The space velocity of the desulfurization tower is 500 h -1 , and the gas flow velocity is 0.7 m / s.

[0121] In this embodiment, temperature and pressure measuring devices are also provided in the packing layers of the first desulfurization tower 5, the second desulfurization tower 6, and the third desulfurization tower 7.

[0122] In this embodiment, a relief pipe is also provided on the clean gas outlet branch pipe.

[0123] Embodiment 3

[0124] This embodiment provides a method for removing organic sulfur from coal gas. Among them, this method for removing organic sulfur from coal gas uses the system for removing organic sulfur from coal gas provided in Embodiment 1, and it includes the following steps:

[0125] The coal gas used in this embodiment is the blast furnace gas after rough purification. The total sulfur in the coal gas is less than 300 mg / m 3 and greater than or equal to 100 mg / m 3 , the coal gas pressure is 12 KPa, the dust content is less than 10 mg / m 3 , the coal gas temperature is 80 °C, and the flow rate is 300000 Nm 3 / h;

[0126] Open the first cut-off valve V1, the third cut-off valve V3, the seventh cut-off valve V7, and the ninth cut-off valve V9, and keep other valves such as the eighth cut-off valve V8, the tenth cut-off valve V10, the second cut-off valve V2, and the fourth cut-off valve V4 in the closed state;

[0127] The blast furnace gas enters the first desulfurization tower 5 and the second desulfurization tower 6 respectively through the coal gas inlet main pipe 1 and the coal gas inlet branch pipe. When the blast furnace gas passes through the packing layer in the desulfurization tower, inorganic sulfur such as H2S and organic sulfur (COS, CS2, thiophene, mercaptan, thioether, etc.) are adsorbed by the loaded new hydrophobic molecular sieve. The total sulfur of the purified coal gas is less than 20 mg / m 3 , and this purified coal gas (clean gas) respectively passes through the clean gas outlet branch pipe from the outlet of the desulfurization tower, converges to the clean gas outlet main pipe 2, and is sent to the subsequent process section;

[0128] After operating for 3 days, the desulfurization tower is regenerated. Open the fifth cut-off valve V5 and the eleventh cut-off valve V11, and close the first cut-off valve V1 and the seventh cut-off valve V7 to regenerate the first desulfurization tower 5. Start the regeneration gas blower 10, open the fifteenth cut-off valve V15, and make the clean gas enter the regeneration gas blower 10. The gas volume is 4000 Nm 3 / h, boost its pressure by 10 KPa, open the sixteenth cut-off valve V16, the thirteenth cut-off valve V13, the eighth cut-off valve V8, and the second cut-off valve V2. The pressurized clean coal gas regenerated gas enters the first desulfurization tower 5 through the gas heating device 13, and enters the incinerator 8 through the regeneration desorption gas branch pipe and the regeneration desorption gas main pipe 4. The clean coal gas is mixed with air and burned. When the temperature in the main combustion chamber reaches above 500 °C, the regenerated gas is heated in the gas heating device 13 in the flue gas discharge chamber of the incinerator to a temperature of 200 °C. When the heated regenerated gas passes through the packing layer in the first desulfurization tower 5, it heats the packing layer. The packing layer is equipped with a temperature measuring device to monitor the temperature change; when the temperature of the packing layer reaches 200 °C, heat preservation is carried out to maintain the temperature at 180 °C - 210 °C. At this time, the inorganic sulfur and organic sulfur such as H2S adsorbed by the adsorbent are desorbed. When the organic sulfur is desorbed, it is converted into inorganic sulfur. After the sulfur is desorbed, it enters the regenerated gas, which is called the regeneration desorption gas;

[0129] The regeneration desorption gas enters the incinerator 8 through the regeneration desorption gas branch pipe and the regeneration desorption gas main pipe 4. The air supplied by the air blower 11 is also preheated by the air preheating device 14 in the flue gas discharge chamber and then enters the incinerator 8. The regeneration desorption gas and air are burned in the incinerator, and the combustion temperature is 900 °C; at this time, the inorganic sulfur such as H2S contained in the regeneration desorption gas, and the organic sulfur that has not been converted into inorganic sulfur is converted into SO2. The flue gas after combustion contains a high concentration of SO2, which is discharged into the flue gas discharge chamber and sent to the subsequent treatment section for acid making after hierarchical heat recovery; the high-pressure steam generated by the heat recovery in the flue gas discharge chamber can be used to drive the regenerated gas blower to save electric energy; after the heat preservation desorption lasts for 1 d, the first desulfurization tower 5 is cooled. The specific cooling process includes: closing the sixteenth cut-off valve V16 and the thirteenth cut-off valve V13, opening the fourteenth cut-off valve V14, and the clean coal gas enters the first desulfurization tower 5 as the regenerated gas through the regenerated gas intake main pipe 3 for cooling. After the cooling process ends (cooled to 80 °C), the first desulfurization tower 5 has the adsorption capacity, and the regeneration of the first desulfurization tower 5 is completed; close the eighth cut-off valve V8, the second cut-off valve V2, and the fourteenth cut-off valve V14, open the first cut-off valve V1 and the seventh cut-off valve V7, close the third cut-off valve V3 and the ninth cut-off valve V9, open the sixteenth cut-off valve V16, the thirteenth cut-off valve V13, the tenth cut-off valve V10, and the fourth cut-off valve V4 to carry out desorption regeneration on the second desulfurization tower 6. The process is the same as the regeneration process of the first desulfurization tower 5, and then the third desulfurization tower 7 is regenerated in turn.

[0130] According to this process, it circulates. When the number of desulfurization towers increases, the regeneration process is carried out step by step as described above.

[0131] In this embodiment, deaerated water can also be provided to the steam generating device through the steam drum. The deaerated water is heated by the steam generating device to generate steam, and the generated steam is then sent to the steam drum for steam-water separation to obtain steam after water removal. The steam after water removal is then sent to the regeneration air blower to drive the regeneration air blower, which can save power consumption. The steam can also be supplied to other users externally to save costs.

[0132] As mentioned above, the above are only specific embodiments of the present invention, and the scope of the invention cannot be limited by them. Therefore, the replacement of equivalent components or equivalent changes and modifications made according to the scope of protection of the present invention should still fall within the scope covered by this patent. In addition, the technical features in the present invention, between technical features, between technical features and technical inventions, and between technical inventions can be freely combined and used.

Claims

1. A system for removing organic sulfur from coal gas, characterized in that, The system for removing organic sulfur from coal gas includes: at least two desulfurization towers, an incinerator, a regenerated gas blower, a steam drum, and an air blower; The incinerator includes a main combustion chamber and a flue gas discharge chamber, and at least a gas heating device, a steam generating device, and an air preheating device are arranged in the flue gas discharge chamber; The liquid inlet of the steam drum is connected to a deaerated water pipeline, the liquid outlet of the steam drum is connected to the steam inlet of the steam drum through a pipeline via the steam generating device, and the steam outlet of the steam drum is connected to the regenerated gas blower through a pipeline; wherein, the regenerated gas blower is driven in a form combining electricity and steam; The gas inlets of the desulfurization towers are respectively and switchably connected to the main coal gas inlet pipe through coal gas inlet branch pipes; the coal gas inlet branch pipes are also respectively connected with regenerated desorption gas branch pipes, and the regenerated desorption gas branch pipes are respectively and switchably connected to the main regenerated desorption gas pipe; The gas outlets of the desulfurization towers are respectively and switchably connected to the main clean coal gas outlet pipe through clean coal gas outlet branch pipes; the clean coal gas outlet branch pipes are also respectively connected with regenerated gas inlet branch pipes, and the regenerated gas inlet branch pipes are respectively and switchably connected to the main regenerated gas inlet pipe; the packing used in the packing layer of the desulfurization tower is a copper-modified ZSM-5 molecular sieve material, which contains a cobalt-molybdenum-nickel series catalyst; The main clean coal gas outlet pipe is connected to the inlet of the regenerated gas blower, and the outlet of the regenerated gas blower is respectively and switchably connected to the main regenerated gas inlet pipe and the inlet of the gas heating device through a pipeline; the outlet of the gas heating device is switchably connected to the main regenerated gas inlet pipe through a pipeline, and the main regenerated desorption gas pipe is also connected to the inlet of the main combustion chamber of the incinerator; or the main clean coal gas outlet pipe is connected to the inlet of the regenerated gas blower, and the outlet of the regenerated gas blower is switchably connected to the main regenerated gas inlet pipe through a pipeline; the steam outlet of the steam drum is also switchably connected to the main regenerated gas inlet pipe through a pipeline; the outlet of the regenerated gas blower is also switchably connected to the inlet of the gas heating device through a pipeline; the outlet of the gas heating device is connected to the inlet of the main combustion chamber of the incinerator through a pipeline, and the main regenerated desorption gas pipe is connected to the inlet of the main combustion chamber of the incinerator via a condensation device; The outlet pipeline of the air blower is connected to the inlet of the main combustion chamber of the incinerator after passing through the air preheating device.

2. The system for removing organic sulfur from coal gas according to claim 1, wherein Cut-off valves are arranged on the coal gas inlet branch pipes, the regenerated desorption gas branch pipes, the clean coal gas outlet branch pipes, and the regenerated gas inlet branch pipes; A cut-off valve is arranged on the pipeline connecting the outlet of the regenerated gas blower and the main regenerated gas inlet pipe, and a cut-off valve is arranged on the pipeline connecting the outlet of the regenerated gas blower and the inlet of the gas heating device; A cut-off valve is arranged on the pipeline connecting the outlet of the gas heating device and the main regenerated gas inlet pipe.

3. The system for removing organic sulfur from coal gas according to claim 1 or 2, characterized in that, Temperature and pressure measuring devices are arranged in the packing layer of the desulfurization tower.

4. The system for removing organic sulfur from coal gas according to claim 1 or 2, characterized in that, A blow-off pipe is arranged on the clean coal gas outlet branch pipe.

5. A method for removing organic sulfur from coal gas, characterized in that, The method for removing organic sulfur from coal gas uses the system for removing organic sulfur from coal gas according to any one of claims 1-4, and it includes the following steps: (1) The coarsely purified gas enters the desulfurization tower to adsorb the inorganic sulfur and organic sulfur in the gas, obtaining purified gas; among them, the temperature range of the coarsely purified gas is 20 o °C - 120 o °C, the pressure is less than 0.1 MPa, the total sulfur ≥ 100 mg / m 3 , and the dust content < 10 mg / m 3 ; The total sulfur content of the clean gas < 20 mg / m 3 ; After the adsorption of the desulfurization tower reaches the preset level, the desulfurization tower is regenerated with the pressurized and heated clean gas as the regeneration gas. After the desulfurization tower is heated and raised to the set temperature by the regeneration gas, heat preservation is carried out. During the heat preservation process, the adsorbed inorganic sulfur and organic sulfur are desorbed, and the organic sulfur is catalytically converted into inorganic sulfur; the pressurized and heated clean gas is cut off, and the desulfurization tower is cooled with the unheated clean gas to complete the regeneration process of the desulfurization tower; wherein, the temperature range of the heated clean gas is 180 o C-400 o C, and the pressure difference between the clean gas before and after pressurization ranges from 4KPa to 100KPa; Or after the adsorption of the desulfurization tower reaches the preset level, the desulfurization tower is regenerated with water vapor as the regeneration gas. After the desulfurization tower is heated up to the set temperature by the regeneration gas and kept warm, the adsorbed inorganic sulfur and organic sulfur are desorbed during the heat preservation process, and the organic sulfur is catalytically converted into inorganic sulfur; the obtained regeneration desorption gas is condensed and separated, and then the gas containing inorganic sulfur and organic sulfur obtained after the condensation and separation is mixed with the preheated air and burned in the incinerator; the temperature of the water vapor is greater than 180 o °C, and the pressure range is 0.4 MPa - 0.6 MPa; (3) The regenerated desorbed gas obtained in step (2) is mixed with preheated air and burned in an incinerator to convert the inorganic sulfur and organic sulfur in the regenerated desorbed gas into SO2; (4) The flue gas obtained in step (3) is subjected to staged heat recovery to reduce the flue gas temperature to the target temperature and then sent to the subsequent treatment section; Among them, in step (2), the heat preservation time range is 24h - 48h; In step (3), the temperature range of the combustion is 800 o °C - 1200 o °C; In step (4), the flue gas temperature is reduced to 200 o °C - 500 o °C.

6. The method for removing organic sulfur from coal gas according to claim 5, wherein, In step (1), 1 desulfurization tower is used as a standby and the rest of the desulfurization towers are used for adsorption.

Images