Gas purification device, waste treatment device, gas purification method, and method for operating waste treatment device

Abstract

A gas purification device according to the present invention is provided with: an acid cleaning device that performs cleaning by bringing acid cleaning water into contact with a gas that is generated by thermally decomposing and gasifying a waste; an alkali cleaning device that cleans the gas that has been cleaned by the acid cleaning device, by bringing alkali cleaning water into contact with the gas; and a desulfurization device that removes hydrogen sulfide from the gas that has been cleaned by the alkali cleaning device. The desulfurization device is provided with: a first desulfurization tower which internally comprises a first spray device that sprays a desulfurization liquid onto the gas supplied from the alkali cleaning device; a second desulfurization tower which internally comprises a fluidized bed through which the gas supplied from the first desulfurization tower passes, and a second spray device that sprays the desulfurization liquid toward the fluidized bed; and a regeneration tank which supplies the desulfurization liquid to the first spray device and the second spray device, and recovers the desulfurization liquid used in the first desulfurization tower and the second desulfurization tower. The desulfurization device is also provided with: a first liquid feed pipe for sending the desulfurization liquid from the first desulfurization tower to the regeneration tank; and a second liquid feed pipe for sending the desulfurization liquid from the second desulfurization tower to the regeneration tank.

Description

Gas purification device, waste treatment device, gas purification method, and method for operating a waste treatment device

[0001] The present invention relates to a gas purification apparatus, a waste treatment apparatus, a gas purification method, and a method for operating a waste treatment apparatus.

[0002] In a gasification reforming furnace, which generates reformed gas by thermally decomposing and gasifying waste, the reaction in the furnace is carried out in a reducing atmosphere in which there is no excess oxygen. Therefore, the sulfur content in the waste is mainly hydrogen sulfide (H ) rather than sulfur oxide. ２ In Patent Document 1, hydrogen sulfide (H S) in the reformed gas is converted into hydrogen sulfide (H S) by a desulfurization liquid containing an iron chelate in a desulfurization tower. ２ A desulfurization device for removing sulfur dioxide (S) is disclosed.

[0003] Japanese Patent Application Laid-Open No. 2006-111768

[0004] Since the sulfur content in waste varies, the hydrogen sulfide concentration in the reformed gas derived from waste fluctuates constantly. In particular, reformed gas derived from industrial waste may momentarily record a very high hydrogen sulfide concentration. Such a peak high concentration of hydrogen sulfide (H ２ If hydrogen sulfide (H2S) flows into the desulfurization equipment, the hydrogen sulfide concentration at the outlet of the desulfurization equipment may exceed the allowable limit, which may cause quality assurance issues. Furthermore, in a desulfurization equipment, the contact efficiency between the reformed gas and the desulfurization liquid can be improved by providing a fluidized bed using multiple resin balls inside the desulfurization tower. However, if the hydrogen sulfide concentration in the reformed gas before treatment exceeds the design value for a long period of time, the amount of solid sulfur precipitated in the desulfurization liquid flowing down the fluidized bed increases significantly, restricting the flow of the resin balls in the fluidized bed. As a result, the desulfurization capacity decreases and the self-purification function deteriorates due to poor fluidization of the fluidized bed, leading to blockage of the desulfurization tower. Furthermore, overdesigning the desulfurization equipment to accommodate the increase in hydrogen sulfide concentration leads to increased equipment costs and operating costs for the desulfurization liquid and electricity.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a gas purification apparatus, a waste treatment apparatus, a gas purification method, and an operation method of a waste treatment apparatus that can improve desulfurization capacity while suppressing increases in equipment costs and operating costs.

[0006] In order to solve the above-mentioned problems and achieve the object, (1) a gas purification system according to the present invention is a gas purification system including an acid washing unit that brings acid washing water into contact with gas generated by pyrolysis and gasification of waste to wash the gas, an alkali washing unit that brings alkaline washing water into contact with the gas washed by the acid washing unit to wash the gas, and a desulfurization unit that removes hydrogen sulfide contained in the gas washed by the alkaline washing unit, wherein the desulfurization unit includes a first desulfurization tower having therein a first spray unit that sprays a desulfurization liquid onto the gas supplied from the alkaline washing unit, and a fluidized bed through which the gas supplied from the first desulfurization tower passes and a fluidized bed through which the gas passes. The desulfurization system comprises a second desulfurization tower having a second spray device therein that sprays the desulfurization liquid toward the moving bed, and a regeneration tank that supplies the desulfurization liquid to the first spray device and the second spray device and recovers the desulfurization liquid used in the first desulfurization tower and the second desulfurization tower, characterized by comprising: a first liquid feed pipe connected to the first desulfurization tower and the regeneration tank for feeding the desulfurization liquid from the first desulfurization tower to the regeneration tank; and a second liquid feed pipe connected to the second desulfurization tower and the regeneration tank for feeding the desulfurization liquid from the second desulfurization tower to the regeneration tank.

[0007] (2) The waste treatment apparatus according to the present invention is a waste treatment apparatus comprising a gasification reforming furnace that thermally decomposes and gasifies waste and reforms the resulting gas to produce reformed gas, a gas purification device that purifies the reformed gas produced in the gasification reforming furnace, and a chemical product manufacturing apparatus that uses the purified gas purified in the gas purification device as a raw material to manufacture liquid chemical products, characterized in that the gas purification device is the gas purification device of the invention described in (1) above.

[0008] (3) A gas purification method according to the present invention is a gas purification method comprising an acid washing step in which acid washing water is brought into contact with gas generated by thermal decomposition and gasification of waste to wash the gas; an alkaline washing step in which alkaline washing water is brought into contact with the gas washed in the acid washing step to wash the gas; and a desulfurization step in which hydrogen sulfide contained in the gas washed in the alkaline washing step is removed, wherein the desulfurization step comprises a first desulfurization step in which a desulfurization liquid is sprayed onto the gas washed in the alkaline washing step by a first spray device; and a second desulfurization step in which the desulfurization liquid is sprayed by a second spray device toward a fluidized bed through which the gas desulfurized in the first desulfurization step passes, and wherein the desulfurization liquid used in the first desulfurization step and the desulfurization liquid used in the second desulfurization step are each recovered independently.

[0009] (4) A method for operating a waste treatment device according to the present invention is a method for operating a waste treatment device comprising a gasification and reforming furnace that thermally decomposes and gasifies waste and reforms the resulting gas to produce a reformed gas, a gas purification device that purifies the reformed gas produced in the gasification and reforming furnace, and a chemical product manufacturing device that produces liquid chemical products using the purified gas purified in the gas purification device as a raw material, wherein the gas purification device purifies the reformed gas using the gas purification method of the invention in (3) above.

[0010] The gas purification apparatus, waste treatment apparatus, gas purification method, and method for operating a waste treatment apparatus according to the present invention have the effect of improving desulfurization capacity while suppressing increases in equipment costs and operating costs.

[0011] Fig. 1 is a block diagram showing a schematic configuration of a waste treatment device according to an embodiment. Fig. 2 is a diagram showing a schematic configuration of a desulfurization device according to an embodiment.

[0012] Hereinafter, embodiments of a gas purification apparatus, a waste treatment apparatus, a gas purification method, and an operating method of a waste treatment apparatus according to the present invention will be described. However, the present invention is not limited to these embodiments.

[0013] Fig. 1 is a block diagram showing a schematic configuration of a waste treatment apparatus 1 according to an embodiment. As shown in Fig. 1, the waste treatment apparatus 1 according to an embodiment includes a waste input device 10, a gasification and reforming furnace 50, a cooling and cleaning water circulation device 70, a gas purification device 80, a cleaning water treatment device 90, and a chemical product manufacturing device 100.

[0014] The waste input device 10 inputs waste into the gasification and reforming furnace 50. The gasification and reforming furnace 50 thermally decomposes and gasifies the waste, and reforms the generated gas to produce reformed gas. The gasification and reforming furnace 50 is a vertical furnace, and its approximately lower half is formed as a thermal decomposition section 52 and a melting section 54 located below the thermal decomposition section 52, and its approximately upper half is formed as a gas reforming section 53.

[0015] In the pyrolysis section 52, waste is piled up to form a waste pile layer Q. The waste that forms the waste pile layer Q is gasified by pyrolysis and the incombustible matter is melted. At the bottom of the side wall of the gasification and reforming furnace 50, oxygen (O ２ ) are provided. The gas supply members 20 also function as gas burners for burning liquefied natural gas (LNG) to keep the pyrolysis section 52 at a high temperature. Note that FIG. 1 illustrates one of the gas supply members 20 provided at the bottom of the side wall of the gasification and reforming furnace 50. When the waste is pyrolyzed in the pyrolysis section 52, hydrogen (H ２ ) and carbon monoxide (CO), etc. are generated.

[0016] In the gas reforming section 53, in order to maintain the temperature of the gas generated from the waste deposition layer Q in the thermal decomposition section 52, an oxygen-containing gas is blown in to burn a part of the gas, and the gas is reformed at a high temperature of about 1200°C to produce carbon monoxide (CO), carbon dioxide (CO ２ ), hydrogen (H ２ ) is supplied into the furnace from the gas supply member 20. ２ ) reacts with carbon (C) in the waste to produce carbon monoxide (CO) and carbon dioxide (CO ２) is generated. In addition, because there is high-temperature steam generated from the waste or supplied as water from the outside, carbon (C) and water vapor (H ２ O) to form hydrogen (H ２ ) and carbon monoxide (CO). Furthermore, hydrocarbons generated by the thermal decomposition and partial oxidation of waste materials are converted into water vapor (H ２ O) to form hydrogen (H ２ ) and carbon monoxide (CO). Hydrogen (H ２ The gasification and reforming furnace 50 has a gas reforming section 53 at the top of its side wall, which is filled with liquefied natural gas (LNG) and oxygen (O ２ ) and carbon dioxide (CO ２ ) are provided. The gas supply members 20 also function as gas burners that combust liquefied natural gas (LNG) during start-up to keep the gas reforming unit 53 at a high temperature. Note that FIG. 1 illustrates one of the multiple gas supply members 20 provided at the upper part of the side wall of the gasification reforming furnace 50.

[0017] In the melting section 54, the molten material produced in the pyrolysis section 52 is further heated, and carbon and other substances contained in the molten material are gasified and removed. In the melting section 54, a molten material outlet 58 for discharging the molten material to the outside is provided at the bottom of the gasification and reforming furnace 50.

[0018] A gas duct 60 is provided at the top of the gasification and reforming furnace 50. The gas duct 60 extends from a reformed gas outlet 59 formed at the top and discharges the reformed gas generated in the gas reforming section 53 outside the furnace. A cooling and cleaning water circulating device 70 is provided downstream of the gas duct 60 to cool and clean the reformed gas. The cooling and cleaning water circulating device 70 includes a cooling and cleaning device 71, a settling tank 72, and a heat exchanger 73. The cooling and cleaning device 71 is connected to the gas duct 60 and cools the reformed gas with cooling and cleaning water while removing water-soluble components, dust, carbon particles, and the like from the reformed gas. The settling tank 72 stores the cooling and cleaning water used to cool and clean the reformed gas in the cooling and cleaning device 71 and separates solids contained in the cooling and cleaning water by settling. The heat exchanger 73 cools the cooling and cleaning water from which the solids have been separated. The cooling and cleaning water cooled by the heat exchanger 73 is returned to the cooling and cleaning device 71.

[0019] A gas purification unit 80 is provided downstream of the cooling and cleaning unit 71 to purify the reformed gas cooled and cleaned in the cooling and cleaning unit 71, to produce purified gas that can be used as fuel gas. The gas purification unit 80 has an acid cleaning unit 81, an alkali cleaning unit 82, a desulfurization unit 83, and a dehumidification unit 84. The acid cleaning unit 81 performs an acid cleaning process in which the reformed gas cooled and cleaned in the cooling and cleaning unit 71 is brought into contact with acid cleaning water to dissolve and remove heavy metals, thereby cleaning the reformed gas. The alkali cleaning unit 82 performs an alkali cleaning process in which the reformed gas cleaned in the acid cleaning process is brought into contact with alkali cleaning water to remove hydrogen chloride from the reformed gas for cleaning. The desulfurization unit 83 removes hydrogen sulfide (H ２ In the dehumidifying device 84, a desulfurization process is carried out to remove hydrogen sulfide (H ２ A dehumidification process is then carried out to remove moisture from the reformed gas from which the sulfur dioxide (S) has been removed. Depending on the required specifications of the downstream equipment, the dehumidification process may be omitted or an electric dust remover or the like may be added.

[0020] The acid washing device 81 and the alkaline washing device 82 of the gas purification device 80 are connected to a washing water treatment device 90. The washing water treatment device 90 receives a portion of the acid washing water and a portion of the alkaline washing water used for washing the reformed gas from the acid washing device 81 and the alkaline washing device 82, respectively, and removes components dissolved and captured in the acid washing device 81 and the alkaline washing device 82 from the acid washing water and the alkaline washing water.

[0021] The chemical product manufacturing apparatus 100 receives purified gas from the gas purification apparatus 80 and extracts hydrogen (H ２ ) and carbon monoxide (CO) as raw materials, and synthesizes and produces ethanol as a liquid chemical product by, for example, a catalytic reaction. In addition to ethanol, the chemical product manufacturing apparatus 100 also synthesizes hydrogen (H ２ Liquid chemical products such as dimethyl ether and methanol may be produced using ethanol (O2) and carbon monoxide (CO) as raw materials.

[0022] 2 is a diagram showing a schematic configuration of a desulfurization device 83 according to an embodiment. The desulfurization device 83 according to an embodiment includes a first desulfurization tower 831, a second desulfurization tower 832, a regeneration tank 833, and the like.

[0023] The first desulfurization tower 831 has a first spray device 8312 inside a cylindrical hollow tower that sprays a desulfurization liquid 830 onto the reformed gas that has been cleaned by the alkali cleaning device 82. A gas duct 8311 is connected to the side wall of the lower part of the first desulfurization tower 831. The reformed gas (undesulfurized gas) that has been cleaned by the alkali cleaning device 82 is sent into the first desulfurization tower 831 through the gas duct 8311. Inside the first desulfurization tower 831, a first spray device 8312 is arranged above the gas duct 8311. The first spray device 8312 sprays a desulfurization liquid 830 containing an iron chelating agent (iron chelate complex) onto the reformed gas that has been sent into the first desulfurization tower 831 through the gas duct 8311, thereby removing hydrogen sulfide (H ２ The desulfurization liquid 830 is not limited to one containing an iron chelating agent, and may be any liquid containing hydrogen sulfide (H ２ Any material capable of removing hydrogen sulfide (H ２The reformed gas from which a portion of the hydrogen sulfide (H S) has been removed is discharged from a gas duct 8313 connected to the top of the first desulfurization tower 831. The reformed gas is sprayed from a first spray device 8312 to remove hydrogen sulfide (H S) from the reformed gas. ２ The desulfurization liquid 830 used to remove sulfur dioxide and sulfur dioxide (S) accumulates in the lower part of the first desulfurization tower 831. The desulfurization liquid 830 accumulated in the lower part of the first desulfurization tower 831 is discharged to the outside through a first recovery pipe 8304, which is a first liquid transfer pipe connected to the bottom of the first desulfurization tower 831, and is sent to the regeneration tank 833 by a first recovery pump 834.

[0024] The second desulfurization tower 832 has a fluidized bed 8321 and a second spray device 8322 that sprays the desulfurization liquid 830 toward the fluidized bed 8321 inside a cylindrical hollow tower. A gas duct 8313 is connected to the side wall of the lower part of the second desulfurization tower 832. Hydrogen sulfide (H ２ The reformed gas from which a portion of the sulfur dioxide (SO2) has been removed (desulfurized) is sent through a gas duct 8313 into the second desulfurization tower 832. Inside the second desulfurization tower 832, a fluidized bed 8321 is arranged above the gas duct 8313. In the fluidized bed 8321, a plurality of resin balls are packed on a perforated plate-shaped support member as gas-liquid contact packing. The fluidized bed 8321 is configured so that the plurality of resin balls easily flow as the reformed gas sent into the second desulfurization tower 832 through the gas duct 8313 and injected from below rises. Inside the second desulfurization tower 832, a second spray device 8322 is arranged above the fluidized bed 8321. The second spray device 8322 sprays desulfurization liquid 830 toward the fluidized bed 8321 below. The desulfurization liquid 830 sprayed from the second spray device 8322 toward the fluidized bed 8321 is promoted to come into contact with the reformed gas by the plurality of resin balls moving in the fluidized bed 8321, and the hydrogen sulfide (H ２ S) is efficiently removed. ２ The reformed gas (desulfurized gas) from which sulfur dioxide (S) has been removed is discharged from a gas duct 8324 connected to the top of the second desulfurization tower 832 and sent to the dehumidification device 84.

[0025] Also, hydrogen sulfide (H ) in the reformed gas is sprayed from the second spray device 8322. ２The desulfurization liquid 830 used to remove sulfur dioxide and sulfur dioxide (S) is discharged and accumulated in the lower part of the second desulfurization tower 832 through a discharge pipe 8323 provided below the fluidized bed 8321. The desulfurization liquid 830 accumulated in the lower part of the second desulfurization tower 832 is discharged to the outside through a second recovery pipe 8305, which is a second liquid transfer pipe connected to the bottom of the second desulfurization tower 832, and is sent to the regeneration tank 833 by a second recovery pump 835.

[0026] In the regeneration tank 833, the desulfurization liquid 830 containing the iron chelating agent is sent by a supply pump 836 from a supply pipe 8301 connected to the side wall of the regeneration tank 830, and is supplied to the first spray device 8312 and the second spray device 8322 via a first branch pipe 8302 and a second branch pipe 8303. At the same time, the desulfurization liquid 830 used for desulfurization in the first desulfurization tower 831 and the second desulfurization tower 832 is recovered in the regeneration tank 833. The regeneration tank 833 receives a supply of air from the outside, and hydrogen sulfide (H ２ The desulfurized liquid 830 is regenerated by oxidizing sulfur dioxide (S) and reducing it. The solid sulfur contained in the recovered desulfurized liquid 830 is discharged to the outside from the bottom. The desulfurized liquid 830 from which the solid sulfur has been removed is then supplied again to the first spray device 8312 of the first desulfurization tower 831 and the second spray device 8322 of the second desulfurization tower 832, thereby circulating the desulfurized liquid 830.

[0027] In the desulfurization device 83 according to this embodiment, even if the hydrogen sulfide concentration in the reformed gas at the inlet side of the first desulfurization tower 831 increases suddenly or over a long period of time, the desulfurization liquid 830 is sprayed onto the reformed gas by the first spray device 8312 in the first desulfurization tower 831, so the hydrogen sulfide concentration at the inlet side of the second desulfurization tower 832 is suppressed to approximately the design concentration. Therefore, it is possible to suppress the hydrogen sulfide concentration at the outlet side of the second desulfurization tower 832 from exceeding the design concentration.

[0028] Furthermore, since the sulfur concentration in the desulfurization liquid 830 in the second desulfurization tower 832 is kept low, it is possible to prevent the flow of the resin balls in the fluidized bed 8321 from being hindered, and it is possible to achieve the desulfurization performance of the second desulfurization tower 832 as designed. Furthermore, since the self-cleaning function of the resin balls due to their flow operates normally in the fluidized bed 8321, it is possible to avoid unplanned equipment shutdowns due to blockage of the fluidized bed 8321 in the second desulfurization tower 832. Furthermore, since the second desulfurization tower 832 does not need to be over-designed to increase its desulfurization capacity, it is possible to prevent excessive capital expenses (CAPEX) and operating expenses (OPEX).

[0029] In the desulfurization device 83 according to this embodiment, the desulfurization liquid 830 is independently recovered from the first desulfurization tower 831 and the second desulfurization tower 832 into the regeneration tank 833. Therefore, even if the hydrogen sulfide concentration in the reformed gas increases suddenly or over a long period of time at the inlet side of the first desulfurization tower 831, the solid sulfur generated in the first desulfurization tower 831 is transported to the regeneration tank 833 through the first recovery pipe 8304 without passing through the second desulfurization tower 832. Therefore, it is possible to prevent the solid sulfur from interfering with the flow of the resin balls in the fluidized bed 8321 provided in the second desulfurization tower 832, and it is also possible to prevent problems caused by poor flow of the resin balls.

[0030] In addition, the desulfurization performance of the first desulfurization tower 831, which is simply gas-liquid contact between the desulfurized liquid 830 sprayed and the reformed gas, is lower than that of the second desulfurization tower 832 using the fluidized bed 8321. For example, in the second desulfurization tower 832 using the fluidized bed 8321, the desulfurization performance of the second desulfurization tower 832 using the fluidized bed 8321 is lower than that of the second desulfurization tower 832 using the fluidized bed 8321. ２ The first desulfurization tower 831, which only uses spray, has a removal efficiency of 98% or more. ２ On the other hand, when the hydrogen sulfide concentration in the reformed gas at the inlet side of the first desulfurization tower 831 rises to an extremely high concentration (for example, on the order of several thousand ppm), the first desulfurization tower 831 exhibits a sufficiently effective desulfurization capability. For example, when the design concentration at the inlet side of the second desulfurization tower 832 is 2000 ppm, the first desulfurization tower 831 can remove 50% of the hydrogen sulfide (H ２If S) can be removed, the first desulfurization tower 831 can handle reformed gas up to 4000 ppm at the inlet side.

[0031] The first desulfurization tower 831 is not provided with a fluidized bed for desulfurization, and is equipped with only the first spray device 8312, so that even when operated for a long period of time under high load, it is possible to prevent the first desulfurization tower 831 from being clogged with solid sulfur. Furthermore, the equipment costs for the first desulfurization tower 831 are cheaper than those for the second desulfurization tower 832 because a fluidized bed is not provided.

[0032] The desulfurization apparatus 83 according to the embodiment can reduce planned shutdown periods for equipment maintenance while minimizing increases in equipment costs. Furthermore, the desulfurization apparatus 83 according to the embodiment can reduce the frequency of unexpected shutdowns of the desulfurization apparatus 83 and, ultimately, the waste treatment apparatus 1, caused by blockage of the second desulfurization tower 832. These improvements significantly improve the continuity and safety of gas supply to processes downstream of the desulfurization step in the desulfurization apparatus 83, thereby improving the yield of final products (such as ethanol) in the waste treatment apparatus 1. Furthermore, the cost required for maintenance of the desulfurization apparatus 83, including the second desulfurization tower 832, can be reduced, greatly contributing to improved profits.

[0033] The present invention can provide a gas purification apparatus, a waste treatment apparatus, a gas purification method, and a method for operating a waste treatment apparatus that can improve desulfurization capacity while suppressing increases in equipment costs and operating costs.

[0034] REFERENCE SIGNS LIST 1 Waste treatment device 10 Waste input device 20 Gas supply member 50 Gasification reforming furnace 52 Pyrolysis section 53 Gas reforming section 54 Melting section 58 Melt outlet 59 Reformed gas outlet 60 Gas duct 70 Cooling and cleaning water circulation device 71 Cooling and cleaning device 72 Settling tank 73 Heat exchanger 80 Gas purification device 81 Acid cleaning device 82 Alkali cleaning device 83 Desulfurization device 84 Dehumidification device 90 Cleaning water treatment device 100 Chemical product manufacturing device 830 Desulfurization liquid 831 First desulfurization tower 832 Second desulfurization tower 833 Regeneration tank 834 First recovery pump 835 Second recovery pump 836 Supply pump 8301 Supply pipe 8302 First branch pipe 8303 Second branch pipe 8304 First recovery pipe 8305 Second recovery piping 8311 Gas duct 8312 First spray device 8313 Gas duct 8321 Fluidized bed 8322 Second spray device 8323 Discharge piping 8324 Gas duct

Claims

1. A gas purification device comprising: an acid washing device that contacts and washes acid washing water with a gas generated by pyrolyzing and gasifying waste; an alkali washing device that contacts and washes alkali washing water with the gas washed by the acid washing device; and a desulfurization device that removes hydrogen sulfide contained in the gas washed by the alkali washing device, wherein the desulfurization device includes: a first desulfurization tower having a first spray device inside for spraying desulfurization liquid onto the gas supplied from the alkali washing device; a second desulfurization tower having a fluidized bed through which the gas supplied from the first desulfurization tower passes and a second spray device for spraying the desulfurization liquid toward the fluidized bed; and a regeneration tank for supplying the desulfurization liquid to the first spray device and the second spray device and recovering the desulfurization liquid used in the first desulfurization tower and the second desulfurization tower, and is characterized in that a first liquid supply pipe connected to the first desulfurization tower and the regeneration tank for sending the desulfurization liquid from the first desulfurization tower to the regeneration tank and a second liquid supply pipe connected to the second desulfurization tower and the regeneration tank for sending the desulfurization liquid from the second desulfurization tower to the regeneration tank are provided.

2. A waste treatment device comprising: a gasification reforming furnace that reforms a gas generated by pyrolyzing and gasifying waste to generate a reformed gas; a gas purification device that purifies the reformed gas generated by the gasification reforming furnace; and a chemical product manufacturing device that manufactures liquid chemical products using the purified gas purified by the gas purification device, wherein the waste treatment device is characterized in that the gas purification device according to claim 1 is used.

3. An acid washing step of contacting the gas generated by pyrolyzing and gasifying waste with acid washing water for washing, an alkali washing step of contacting the gas washed in the acid washing step with alkali washing water for washing, and a desulfurization step of removing hydrogen sulfide contained in the gas washed in the alkali washing step. The gas purification method includes: the desulfurization step includes a first desulfurization step of spraying a desulfurization liquid onto the gas washed in the alkali washing step by a first spraying device, and a second desulfurization step of spraying the desulfurization liquid onto a fluidized bed through which the gas desulfurized in the first desulfurization step passes by a second spraying device. The gas purification method is characterized in that the desulfurization liquid used in the first desulfurization step and the desulfurization liquid used in the second desulfurization step are independently recovered respectively.

4. An operating method of a waste treatment apparatus including a gasification reforming furnace for reforming the gas generated by pyrolyzing and gasifying waste to generate a reformed gas, a gas purification apparatus for purifying the reformed gas generated in the gasification reforming furnace, and a chemical product manufacturing apparatus for manufacturing a liquid chemical product using the purified gas purified by the gas purification apparatus. The operating method of the waste treatment apparatus is characterized in that the gas purification apparatus purifies the reformed gas using the gas purification method according to claim 3.

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