JP2012071226A - Gas treatment facility with mercury removing function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively remove mercury by a cupric absorbent, in treating gases over a wide temperature range.SOLUTION: This gas treatment facility includes a mercury removing means 2 filled with the cupric absorbent 3 of absorbing mercury containing copper as a principal component, and for absorbing, with the cupric absorbent, the mercury contained in combustion exhaust gas (temperature up to 250°C), by making the combustion exhaust gas from an incineration facility 1 flow therethrough, and removes the mercury contained in the processing gas over the wide temperature range up to 250°C, without using active carbon limited in an applied temperature range.

Description

  The present invention relates to a gas processing facility having a mercury removing function.

  For raw material gas (gasification gas etc.) produced from fossil fuel, biomass, waste, combustion exhaust gas discharged from various incineration facilities and combustion facilities, gas produced from nature (natural gas) Since impurities that have an adverse effect are included, it is essential to remove the impurities. In particular, mercury that has a high vapor pressure and exists as vapor is difficult to remove with a filter or the like, and metal mercury vapor is insoluble in water and cannot be removed by washing with washing water. For this reason, activated carbon using an adsorption phenomenon is used to remove mercury.

  Activated carbon for removing mercury is inexpensive, but the temperature range (application temperature) in which mercury can be adsorbed is limited to a low temperature range of 60 ° C. or less, for example. Moreover, it is necessary to treat the activated carbon after adsorbing mercury as waste, which results in a large amount of waste being discharged in order to remove mercury and the like.

  Under such circumstances, a technique for absorbing mercury using a copper-based absorbent mainly composed of copper (for example, see Patent Document 1) has been proposed. The inventors of the present application have studied various techniques for removing mercury from various processing gases such as raw material gas (such as gasification gas), combustion exhaust gas, and natural gas by using this type of copper-based absorbent. Although copper-based absorbents are thought to be able to remove mercury from processing gases in a wide temperature range, effective techniques for applying copper-based absorbents to processing gases in a wide temperature range have been established. The current state is in the process.

JP 2005-161255 A

  The present invention has been made in view of the above situation, and a mercury removing function capable of removing mercury contained in a processing gas having a wide temperature range of 250 ° C. or lower without using activated carbon with a limited application temperature range. It aims at providing the gas processing equipment which has this.

  In order to achieve the above object, a gas processing facility having a mercury removing function according to the present invention according to claim 1 is filled with a copper-based absorbent that absorbs mercury mainly composed of copper, and a processing gas having a temperature of 250 ° C. or less. Mercury removing means for allowing the copper-based absorbent to absorb mercury contained in the processing gas by being distributed is provided.

  In the present invention according to claim 1, it is possible to remove mercury contained in the processing gas in a wide temperature range of 250 ° C. or less by the mercury removing means without using activated carbon having a limited application temperature range.

  A gas treatment facility having a mercury removal function according to a second aspect of the present invention is the gas treatment facility having the mercury removal function according to the first aspect, wherein the impurities contained in the process gas are removed by a wet process. A removal means is provided.

  In the present invention according to claim 2, impurities can be removed by the wet impurity removing means, and mercury contained in the processing gas having a temperature of 250 ° C. or lower can be removed by the mercury removing means.

  The gas treatment facility having a mercury removal function according to claim 3 is the gas treatment facility having the mercury removal function according to claim 2, wherein the treatment gas is a combustion exhaust gas, A gas processing facility having a mercury removing function according to a fourth aspect of the present invention is the gas processing facility having a mercury removing function according to the second aspect, wherein the processing gas is a gasification gas.

  In the present invention according to claims 3 and 4, impurities contained in the high-temperature combustion exhaust gas and gasification gas can be removed by the wet impurity removing means, and mercury can be removed by the mercury removing means.

  According to a fifth aspect of the present invention, there is provided a gas processing facility having a mercury removing function according to the present invention, wherein the mercury is disposed upstream of the wet impurity removing means in the gas processing facility having the mercury removing function according to the third or fourth aspect. A removal means is provided, and the wet impurity removal means can remove mercury in the processing gas before the temperature drops.

  According to a sixth aspect of the present invention, there is provided a gas processing facility having a mercury removing function according to the present invention, wherein the mercury is disposed downstream of the wet impurity removing means in the gas treating facility having the mercury removing function according to the third or fourth aspect. Metallic mercury that is not removed by the wet impurity removing means (insoluble in water) can be removed.

  A gas processing facility having a mercury removing function according to a seventh aspect of the present invention is the gas processing facility having a mercury removing function according to the third or fourth aspect, wherein the upstream side and the downstream side of the wet impurity removing unit. Mercury removing means is provided on each side, and mercury in the processing gas before the temperature is lowered by the wet impurity removing means and metallic mercury that is not removed by the wet impurity removing means (insoluble in water) can be removed. it can.

  The gas treatment facility having a mercury removal function according to claim 8 is the gas treatment facility having the mercury removal function according to claim 2, wherein the treatment gas is a naturally occurring gas. A feature is that impurities contained in naturally occurring gas (natural gas) can be removed by wet impurity removing means, and mercury contained in gas existing in natural gas at 250 ° C. or lower can be removed by mercury removing means. .

  A gas processing facility having a mercury removing function according to a ninth aspect of the present invention is a gas processing facility having a mercury removing function according to the eighth aspect, wherein the gas (natural gas) existing in nature is liquefied. Means are provided.

  In the present invention according to claim 9, by providing the mercury removing means upstream of the liquefying means for liquefying natural gas or in the middle of the liquefying means, the temperature of 250 ° C. or less before liquefaction (process of liquefaction). Mercury contained in natural gas can be removed, and the influence of mercury on the equipment of the liquefaction means can be prevented.

  The gas treatment facility having a mercury removal function of the present invention can remove mercury contained in a treatment gas in a wide temperature range of 250 ° C. or lower without using activated carbon with a limited application temperature range.

1 is a schematic system diagram of a gas processing facility according to a first embodiment of the present invention. It is a schematic system diagram of the gas treatment equipment concerning the 2nd example of the present invention. It is a schematic system diagram of the gas treatment equipment concerning the 3rd example of the present invention. It is a schematic system diagram of the gas treatment equipment concerning the 4th example of the present invention. It is a schematic system diagram of the gas treatment equipment concerning the 5th example of the present invention. It is a schematic system diagram of the gas treatment equipment concerning the 6th example of the present invention.

  A first embodiment and a second embodiment will be described with reference to FIGS.

  FIG. 1 shows a schematic system of a gas processing facility having a mercury removing function according to the first embodiment of the present invention, and FIG. 2 shows a schematic system of a gas processing facility having a mercury removing function according to a second embodiment of the present invention. It is shown. In the first and second embodiments, combustion exhaust gas from incineration equipment or the like is used as the processing gas.

  The incineration facility 1 is, for example, a waste incineration facility or a facility for processing waste such as a battery or a fluorescent lamp, and is a facility for discharging high-temperature exhaust gas. Examples of equipment that uses combustion exhaust gas as processing gas include exhaust gas processing equipment for power generation equipment.

  A first embodiment will be described with reference to FIG.

  As shown in the figure, the temperature of the combustion exhaust gas as the processing gas from the incineration facility 1 is adjusted by, for example, cooling means (the combustion exhaust gas is cooled), and the temperature of the combustion exhaust gas (250 ° C. or less) is mercury. The mercury removal means 2 absorbs and removes mainly the metallic mercury. The mercury removing means 2 is filled with a copper-based absorbent 3 that mainly absorbs copper and absorbs mercury, and the copper-based absorbent 3 absorbs mercury contained in the combustion exhaust gas when the combustion exhaust gas flows.

  The combustion exhaust gas from which mercury has been removed by the mercury removal means 2 is sent to the wet impurity removal means 4, where the impurities contained in the combustion exhaust gas are washed water (water, alkaline aqueous solution, neutral aqueous solution, acidic aqueous solution). Removed by. That is, a nozzle 5 is provided on the upper part of the wet impurity removing means 4, and cleaning water is ejected from the nozzle 5, whereby impurities in the combustion exhaust gas are removed by the cleaning water. As impurities, dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities are removed by washing water.

  The wet impurity removing means 4 has been described by taking as an example a means of injecting wash water pressurized from above into the combustion exhaust gas, but it is also possible to inject wash water from below into the combustion exhaust gas. is there. Also, means for directly blowing combustion exhaust gas into the wash water to dissolve and remove impurities in the wash water, means for removing the impurities by bringing the combustion exhaust gas into contact with the water film of the wash water sprayed on the filling, and washing It is possible to apply means for removing impurities by dispersing water with a rotating body and bringing it into contact with combustion exhaust gas.

  In addition to water and aqueous solutions (alkaline, neutral, acidic), a slurry mixed with an insoluble substance and a solution containing an organic substance can be used as the washing water for the wet impurity removing means.

  The combustion exhaust gas from which mercury has been removed from the high-temperature combustion exhaust gas by the mercury removal means 2 and dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities have been removed by the wet impurity removal means 4 is sent from the chimney 6 to the atmosphere. Released.

  In the incineration facility 1 described above, it is possible to remove mercury contained in high-temperature combustion exhaust gas at 250 ° C. or lower without using activated carbon with a limited range of application temperatures. In addition, dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities can be removed by a wet process.

  A second embodiment will be described with reference to FIG. The same components as those of the processing facility of the first embodiment are denoted by the same reference numerals.

  As shown in the figure, the temperature of the combustion exhaust gas as the processing gas from the incineration facility 1 is adjusted by, for example, cooling means (the combustion exhaust gas is cooled), and the temperature of the adjusted combustion exhaust gas (250 ° C. or less) is wet. The impurities are sent to the impurity removing means 4, and the impurities contained in the combustion exhaust gas are removed by the washing water in the wet impurity removing means 4. That is, a nozzle 5 is provided on the upper part of the wet impurity removing means 4, and cleaning water is ejected from the nozzle 5, whereby impurities in the combustion exhaust gas are removed by the cleaning water. As impurities, dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities are removed by washing water.

  Combustion exhaust gas from which impurities have been removed by the wet impurity removal means 4 and which has been brought to a low temperature of about room temperature is sent to the mercury removal means 2, and the mercury removal means 2 is not capable of being washed away with washing water (insoluble in water). Absorbed and removed. The mercury removing means 2 is filled with a copper-based absorbent 3 that mainly absorbs copper and absorbs mercury, and the copper-based absorbent 3 absorbs mercury contained in the combustion gas when the combustion exhaust gas flows.

  As the wet impurity removing means 4, other means described in the first embodiment can be applied.

  Dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities are removed by the wet impurity removal means 4, and mercury is removed from the combustion exhaust gas at room temperature by the mercury removal means 2, and impurities such as mercury The combustion exhaust gas from which is removed is discharged from the chimney 6 to the atmosphere.

  In the treatment equipment described above, dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities can be removed by a wet process, and the temperature is set to about room temperature without using activated carbon with a limited application temperature range. Mercury contained in combustion exhaust gas can be removed.

  3rd Example, 4th Example, and 5th Example are described based on FIGS. 3-5.

  3 is a schematic system of a gas processing facility having a mercury removing function according to a third embodiment of the present invention, FIG. 4 is a schematic system of a gas processing facility having a mercury removing function according to a fourth embodiment of the present invention, FIG. 5 shows a schematic system of a gas processing facility having a mercury removing function according to a fifth embodiment of the present invention. The same members as those shown in FIGS. 1 and 2 are denoted by the same reference numerals. In the third to fifth embodiments, the gasification gas of the gasification facility is used as the processing gas.

  The gasification facility is, for example, a facility that generates a high-temperature processing gas using a raw material gas (gasification gas) gasified by the gasification facility using fossil fuel, biomass, and waste as raw materials. Then, impurities in the gasification gas are removed to obtain a chemical raw material product or a combustion fuel.

  A third embodiment will be described with reference to FIG.

  As shown in the figure, the temperature of the gasification gas as the high-temperature processing gas generated in the gasification facility 15 is adjusted by, for example, a cooling means (the gasification gas is cooled), and the temperature is adjusted. The gas (250 ° C. or less) is sent to the mercury removing means 2, and the mercury removing means 2 mainly absorbs and removes metallic mercury. The mercury removing means 2 is filled with a copper-based absorbent 3 that mainly absorbs copper and absorbs mercury, and the copper-based absorbent 3 absorbs mercury contained in the gasification gas when the gasification gas flows.

  The gasified gas from which mercury has been removed by the mercury removing means 2 is sent to the wet impurity removing means 4, and the impurities contained in the gasified gas are removed by the cleaning water in the wet impurity removing means 4. That is, a nozzle 5 is provided on the upper part of the wet impurity removing means 4, and cleaning water is ejected from the nozzle 5, whereby impurities in the gasification gas are removed by the cleaning water. As impurities, dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities are removed by washing water.

  As the wet impurity removing means 4, other means described in the first embodiment can be applied.

  The gasification gas from which mercury has been removed from the high-temperature gasification gas by the mercury removal means 2 and dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities have been removed by the wet impurity removal means 4 is, for example, combustion It is used as a fuel for equipment and power generation equipment and as a raw material for chemical synthesis. Since the source gas supplied to the combustion facility and chemical synthesis facility does not contain mercury, the exhaust gas after combustion and products manufactured by chemical synthesis will not be mixed.

  In the treatment facility described above, it is possible to remove mercury contained in a gasification gas having a high temperature of about 250 ° C. without using activated carbon with a limited application temperature range. In addition, dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities can be removed by a wet process.

  A fourth embodiment will be described with reference to FIG.

  As shown in the figure, the temperature of the gasification gas as the high-temperature processing gas generated in the gasification facility 15 is adjusted by, for example, a cooling means (the gasification gas is cooled), and the temperature is adjusted. The gas (250 ° C. or less) is sent to the mercury removing means 2, and the mercury removing means 2 mainly absorbs and removes metallic mercury. The mercury removing means 2 is filled with a copper-based absorbent 3 that mainly absorbs copper and absorbs mercury, and the copper-based absorbent 3 absorbs mercury contained in the gasification gas when the gasification gas flows.

  The gasified gas from which mercury has been removed by the mercury removing means 2 is sent to the dry impurity removing means 16, where the impurities contained in the gasified gas are removed by chemical conversion, physical absorption, or the like. As impurities, dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities are removed.

  The high-temperature gasification gas from which mercury has been removed from the high-temperature gasification gas by the mercury removal means 2 and impurities such as dust, sulfur compounds, and halogen compounds have been removed by the dry impurity removal means 16 is, for example, a combustor of a power generation facility It is used as fuel gas.

  In the treatment facility described above, it is possible to remove mercury contained in a high-temperature gasification gas of 250 ° C. or lower without using activated carbon with a limited application temperature range. Further, dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities can be removed while the gasification gas is maintained at a high temperature by a dry method.

  A fifth embodiment will be described with reference to FIG.

  As shown in the figure, the temperature of the gasification gas as the high-temperature processing gas generated in the gasification facility 15 is adjusted by, for example, a cooling means (the gasification gas is cooled), and the temperature is adjusted. The gas (250 ° C. or lower) is sent to the wet impurity removing means 4, and the impurities contained in the gasification gas are removed by the cleaning water in the wet impurity removing means 4. That is, a nozzle 5 is provided on the upper part of the wet impurity removing means 4, and cleaning water is ejected from the nozzle 5, whereby impurities in the gasification gas are removed by the cleaning water. As impurities, dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities are removed by washing water.

  The gasified gas, which has been subjected to the removal of impurities by the wet impurity removal means 4 and has been brought to a low temperature of about room temperature, is sent to the mercury removal means 2, and the mercury removal means 2 cannot be washed away with wash water (water insoluble) metallic mercury Is absorbed and removed. The mercury removing means 2 is filled with a copper-based absorbent 3 that mainly absorbs copper and absorbs mercury, and the copper-based absorbent 3 absorbs mercury contained in the gasification gas when the gasification gas flows.

  As the wet impurity removing means 4, other means described in the first embodiment can be applied.

  Dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities are removed by the wet impurity removing means 4, and mercury is removed by the mercury removing means 2 from the gasified gas brought to about room temperature. The gasified gas from which impurities have been removed is used, for example, as a fuel for combustion devices and power generation equipment, or as a raw material for chemical synthesis. Since the source gas supplied to the combustion facility and chemical synthesis facility does not contain mercury, the exhaust gas after combustion and products manufactured by chemical synthesis will not be mixed.

  In the treatment equipment described above, dust, sulfur compounds, halogen compounds, nitrogen compounds, and other gaseous impurities can be removed by a wet process, and the temperature is set to about room temperature without using activated carbon with a limited application temperature range. Mercury contained in the gasification gas can be removed.

  A sixth embodiment will be described with reference to FIG.

  FIG. 6 shows a schematic system of a gas processing facility having a mercury removing function according to the sixth embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same member as the member shown in FIG. In the sixth embodiment, natural gas (naturally existing gas) before being liquefied (process to be liquefied) is used as a processing gas.

  Natural gas existing in nature is liquefied and commercialized as liquefied natural gas. Natural gas is liquefied by being cooled by a cooling means (liquefaction means) such as a heat exchanger, but by removing mercury mixed in the natural gas, components such as a heat exchanger (for example, made of aluminum It is necessary to prevent corrosion of plate fins and tubes. This embodiment is a gas processing facility that removes mercury from natural gas without using activated carbon with a limited application temperature range.

  As shown in the figure, natural gas (about room temperature) produced from nature as a processing gas is sent to the mercury removing means 2, and the mercury removing means 2 mainly removes metal mercury. The mercury removing means 2 is filled with a copper-based absorbent 3 that mainly absorbs copper and absorbs mercury, and the copper-based absorbent 3 absorbs mercury contained in the natural gas by circulating the raw material natural gas.

  The natural gas from which the mercury has been removed by the mercury removing means 2 is sent to a heat exchanger 21 as a liquefying means, and cooled to a predetermined temperature to become liquefied natural gas (LNG) and commercialized. The refrigerant in the heat exchanger 21 is pressurized by the compressor 22, converted into a low-temperature and low-pressure refrigerant by adiabatic expansion, and sent to the heat exchanger 21.

  In addition, although the heat exchanger 21 of 1 step is shown in the figure, a cooling cycle can also be comprised in several steps. In this case, it is possible to provide the mercury removing means 2 in the middle of the heat exchanger 21.

  It is also possible to apply a cooling means that compresses natural gas itself and cools it by drastically reducing the pressure. In this case, the mercury removal means 2 is provided on the downstream side of the compression means, and mercury can be removed from the natural gas that has reached a high temperature.

  In the processing facility described above, it is possible to remove mercury contained in the raw material natural gas without using activated carbon having a limited application temperature range on the upstream side of the heat exchanger 21. For this reason, the corrosion by the mercury of the component apparatus of the heat exchanger 21 can be prevented.

  In addition, in FIG. 6, although the gas processing equipment which liquefies the natural gas which exists naturally in the heat exchanger 21 was mentioned as an example, natural gas was compressed as a gas processing equipment which removes mercury from natural gas, It is also possible to apply a gas processing facility that processes the compressed natural gas as a use gas without liquefying.

  The gas treatment equipment having the mercury removal function according to the first to sixth embodiments described above does not use activated carbon with a limited application temperature range, and does not use activated gas with a wide temperature range of 250 ° C. or less (combustion exhaust gas).・ It is possible to remove mercury contained in gasified gas and natural gas.

  The present invention is not limited to the configuration of each of the above-described embodiments, and any processing equipment can be used as long as it is a gas processing facility provided with mercury removing means for removing mercury contained in a processing gas in a wide temperature range of 250 ° C. or less. The gas is not limited to the exemplified combustion exhaust gas, gasification gas, and natural gas, and high-temperature exhaust gas can also be applied. In addition, the constituent equipment to be used and the processing gas to be used can be arbitrarily selected and combined. Is possible.

  The present invention can be used in the industrial field of gas processing equipment having a mercury removal function.

DESCRIPTION OF SYMBOLS 1 Incineration equipment 2 Mercury removal means 3 Copper type absorbent 4 Wet impurity removal means 5 Nozzle 6 Chimney 15 Gasification equipment 16 Dry type impurity removal means 21 Heat exchanger 22 Compressor

Claims (9)

  It is filled with a copper-based absorbent that absorbs mercury mainly composed of copper, and has a mercury removing means that causes the copper-based absorbent to absorb mercury contained in the processing gas by circulating a processing gas having a temperature of 250 ° C. or less. A gas treatment facility having a mercury removal function. The gas processing facility having a mercury removing function according to claim 1,
A gas processing facility having a mercury removing function, comprising wet impurity removing means for removing impurities contained in the processing gas by a wet method. The gas processing facility having a mercury removing function according to claim 2,
The processing gas is combustion exhaust gas. A gas processing facility having a mercury removing function. The gas processing facility having a mercury removing function according to claim 2,
A gas processing facility having a mercury removing function, wherein the processing gas is a gasification gas. In the gas processing facility having a mercury removing function according to claim 3 or claim 4,
A gas treatment facility having a mercury removing function, comprising a mercury removing means upstream of the wet impurity removing means. In the gas processing facility having a mercury removing function according to claim 3 or claim 4,
A gas treatment facility having a mercury removal function, comprising a mercury removal means downstream of the wet impurity removal means. In the gas processing facility having a mercury removing function according to claim 3 or claim 4,
A gas treatment facility having a mercury removal function, characterized in that mercury removal means are provided on the upstream side and downstream side of the wet impurity removal means, respectively. The gas processing facility having a mercury removing function according to claim 2,
The gas processing facility having a mercury removing function, wherein the processing gas is a naturally occurring gas. The gas processing facility having a mercury removing function according to claim 8,
A gas processing facility having a mercury removing function, characterized by comprising a liquefying means for liquefying the naturally occurring gas.

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