[0001]The present invention relates to a gas purifier and a gas purification method, for example, it relates to a gas purification unit and a gas purification method for purifying a gas to be treated, such as coal gasification gas.
BACKGROUND
[0002]Traditionally, the presence of a catalyst, the gas purification system equipped with a COS converter for converting carbonyl sulfide to be treated in a gas such as coal gasification gas to hydrogen sulfide has been proposed (e.g., see Patent Document 1). In this COS converter gas purifier, carbonyl sulfide contained in the coal gasification gas is hydrolyzed to carbon dioxide and hydrogen sulfide by hydrolytic reaction represented by the following reaction formula (1). + H
　COS 2 O⇔H 2 S + CO　　2 · · · formula (1)
CITATION
Patent Document
[0003]
Patent Document 1: Japanese Patent No. 4227676
Summary of the Invention
Problems that the Invention is to Solve
[0004]
　Meanwhile, the hydrolysis reaction shown in the reaction formula (1) is because it is reversible reaction with fever, in reducing carbonyl sulfide from the relationship of the equilibrium limitations is cold conditions advantageous. However, there are cases where ammonia reaction temperature for the hydrolysis of carbonyl sulfide is contained in too low coal gasification gas, the trace components such as a halogen and hydrocarbon deposited. Therefore, in the COS converter, although minor components are hydrolyzed carbonyl sulfide at a higher temperature than the temperature at which precipitation, and the concentration of carbonyl sulfide in the treated gas high (e.g., above 1000 ppm), carbonyl sulfide it may become difficult to reduce to the desired concentration.
[0005]
　The present invention, even when carbonyl sulfide concentration in the treated gas is high, and an object thereof is to provide a gas purifier and a gas purification method carbonyl sulfide concentration can effectively reduce the processing gas.
Means for Solving the Problems
[0006]
　Gas purification apparatus of the present invention, the presence of a first catalyst, the first predetermined temperature, a first conversion unit which the first conversion processing for the hydrogen cyanide contained in the gas to be treated with ammonia, the presence of the second catalyst under the in the first lower than the predetermined temperature the second predetermined temperature, and a second converter for a second conversion processing to the first conversion process hydrogen sulfide to carbonyl sulfide of the treated gas after said object to be processed a cleaning unit for cleaning process of cleaning and removing the ammonia gas is contacted washing liquid and gas-liquid, the hydrogen sulfide of the treated gas to the gas to be treated after the cleaning process by absorbing liquid and gas-liquid contact a desulfurization unit for absorbing and removing, characterized by comprising a.
[0007]
　According to this configuration, halogen and since such first conversion process ammonia by the first conversion portion is washed away with the first cleaning process, the process gas be cooled gas to be treated below the first predetermined temperature it is possible to prevent the precipitation of trace components in. Thus, not only the process of hydrogen cyanide contained in the gas to be treated is not required, carbonyl sulfide while cooled in a second predetermined temperature suitable for the processed gas after the first conversion processing in the conversion processing of carbonyl sulfide it is possible hydrolysis hydrogen sulfide, since converts carbonyl sulfide to be treated in the gas to hydrogen sulfide in two stages of the first conversion processing and the second conversion process, a carbonyl sulfide concentration in the treated gas to the desired concentration efficiency well it becomes possible to decrease. Therefore, even if the carbonyl sulfide concentration in the treated gas is high, it is possible to realize a gas purifier capable of efficiently reducing the carbonyl sulfide concentration in the treated gas.
[0008]
　The gas purification apparatus of the present invention, the cleaning unit includes a first cleaning unit for the first cleaning process the gas to be treated after the first conversion processing by contacting the cleaning solution and the gas-liquid, the second conversion process it is preferred to have been the subject gas to and a second cleaning unit to the second cleaning process by contacting the cleaning solution and gas-liquid. With this configuration, the gas purification device, the ammonia and the halogen to be treated in the gas after the first conversion process can be removed by the first cleaning process of the first cleaning portion, efficiently precipitation of trace components in the treated gas it is possible to prevent the impurities contained in the treated gas after the second conversion process can be removed by the second cleaning process of the second cleaning unit.
[0009]
　The gas purification apparatus of the present invention, raw material to produce the treated gas containing said carbonyl sulfide and gasified, that the generated the gas to be treated with the gasification unit to be supplied to the first converter preferable. With this configuration, the gas purification system, the raw materials such as heavy oil and coal even if the gas to be treated higher carbonyl sulfide concentration gasified is obtained, can be efficiently reduced carbonyl sulfide to be treated in the gas.
[0010]
　The gas purification apparatus of the present invention, the first converter is preferably set to the ammonia the hydrogen cyanide together with a hydrogen sulfide carbonyl sulfide. With this configuration, the first conversion processing, it is possible to use a first catalyst for selectively degrades hydrogen cyanide decomposition of hydrogen cyanide relative to carbonyl sulfide, first different from the second catalyst carbonyl sulfide hydrolyze the catalyst may also be used.
[0011]
　The gas purification apparatus of the present invention, the first predetermined temperature is preferably at 240 ° C. or higher 350 ° C. or less. With this configuration, it is possible to prevent ammonia contained in coal gasification gas after the first conversion process, the deposition of trace components, such as halogen and hydrocarbon more efficiently.
[0012]
　The gas purification apparatus of the present invention, the second predetermined temperature is preferably at 0.99 ° C. or higher 240 ° C. or less. With this configuration, it is possible to convert processed carbonyl sulfide in the second conversion processing efficiently hydrogen sulfide.
[0013]
　Gas purification method of the present invention, the presence of a first catalyst, the first predetermined temperature, a first conversion step of the first transformation process of the hydrogen cyanide contained in the gas to be treated with ammonia, the presence of the second catalyst under the in the first lower than the predetermined temperature the second predetermined temperature, and a second conversion step of the second conversion process for carbonyl sulfide of the treated gas after the first converting process with hydrogen sulfide, the treated a cleaning step of cleaning and removing the ammonia gas is contacted washing liquid and gas-liquid, the ammonia was removed by washing the gas to be treated absorbing solution and gas-liquid contacting said removing absorbed hydrogen sulfide to be treated in the gas characterized in that it comprises a desulfurization step.
[0014]
　According to this method, halogen and since such first conversion process ammonia by the first conversion portion is washed away with the first cleaning process, the process gas be cooled gas to be treated below the first predetermined temperature it is possible to prevent the precipitation of trace components in. Thus, the process of hydrogen cyanide not only becomes unnecessary, the second conversion processing carbonyl sulfide to hydrogen sulfide while cooled gas to be treated was first conversion process to a second predetermined temperature suitable for conversion of carbonyl sulfide It is possible, since converts carbonyl sulfide to be treated in the gas to hydrogen sulfide in two stages of the first conversion processing and the second conversion process, be reduced efficiently carbonyl sulfide concentration in the treated gas to the desired concentration It can become. Therefore, even if the carbonyl sulfide concentration in the treated gas is high, it is possible to realize a gas purification method that can effectively reduce the carbonyl sulfide concentration in the treated gas.
[0015]
　In the gas purification method of the present invention, examples of the washing step, a first cleaning step of the first cleaning process the gas to be treated after the first conversion processing by contacting the cleaning solution and the gas-liquid, the second conversion process it is preferred to have been the subject gas to and a second cleaning step of the second cleaning process by contacting the cleaning solution and gas-liquid. In this way, the gas purification device, the ammonia and the halogen to be treated in the gas after the first conversion process can be removed by the first cleaning process, it is possible to prevent efficiently the precipitation of trace components in the treated gas the impurities contained in the treated gas after the second conversion process can be removed by the second cleaning process.
[0016]
　In the gas purification method of the present invention, it is preferable that raw material is gasified containing gasification step of generating the gas to be treated containing the carbonyl sulfide. In this way, a gas purification apparatus, the raw materials such as heavy oil and coal even if the gas to be treated higher carbonyl sulfide concentration gasified is obtained, can be efficiently reduced carbonyl sulfide to be treated in the gas.
Effect of the invention
[0017]
　According to the present invention, even when the concentration of carbonyl sulfide in the treated gas high, it is possible to realize a gas purifier and a gas purification method carbonyl sulfide can efficiently reduce the processed gas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018]
[1] Figure 1 is a schematic diagram showing an example of a gas purification system according to a first embodiment of the present invention.
FIG. 2 is a schematic view showing another example of a gas purification apparatus according to a first embodiment of the present invention.
FIG. 3 is a schematic view showing another example of a gas purification apparatus according to a first embodiment of the present invention.
[4] FIG. 4 is a schematic diagram showing an example of a gas purification unit according to the second embodiment of the present invention.
FIG. 5 is a schematic view showing another example of a gas purification apparatus according to a second embodiment of the present invention.
FIG. 6 is a schematic view showing another example of a gas purification apparatus according to a second embodiment of the present invention.
DESCRIPTION OF THE INVENTION
[0019]
　The present inventors have found that the carbonyl sulfide converter used in conventional gas purification unit, not be effectively reduced carbonyl sulfide concentration in the processed gas containing a high concentration of carbonyl sulfide such as coal gasification gas focusing on. Then, the present inventors have found that even when using the gas to be treated containing a high concentration of carbonyl sulfide, from the decomposition of hydrogen cyanide contained in the gas to be treated, suitable for conversion of carbonyl sulfide by conversion process carbonyl sulfide to hydrogen sulfide at a temperature, it found that can be reduced to the desired concentration carbonyl sulfide while preventing precipitation of trace components in the treated gas, and have completed the present invention.
[0020]
　Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the following embodiments can be implemented by appropriate modifications.
[0021]
(First Embodiment)
　FIG. 1 is a schematic diagram showing an example of a gas purification device 1 according to a first embodiment of the present invention.
　As shown in FIG. 1, a gas purifying device 1 according to this embodiment, gasifier feed F and oxidant O is fed (gasification unit) 11, disposed downstream of the gasification furnace 11 the first carbonyl sulfide converter (first converter) 12 (hereinafter, referred to as "first 1COS converter 12") and the first spray tower disposed downstream of the 1COS converter 12 (first cleaning portion) 13 and the second carbonyl sulfide converter (second converter) 14 disposed downstream of the first washing column 13 (hereinafter, referred to as "first 2COS converter 14") and, provided on the subsequent stage of the 2COS transducer 14 comprises a second washing column (second cleaning portion) 15, and a desulfurization tower (desulfurization section) 16 disposed downstream of the second washing column 15. Gas turbine 17 is disposed following the desulfurization tower 16.
[0022]
　Gasifier 11, the supplied raw material F and oxidant O gasification gas (gas to be treated) G containing carbonyl sulfide and hydrogen cyanide gasified 1 generates a. Further, the gasification furnace 11, the gasification gas G generated hot 1 supplies to the 1COS transducer 12. As the raw material F, not particularly limited as long as by-produced carbonyl sulfide, for example, higher sulfur concentrations such as coal and heavy oil are used. Among them, the gas purification unit 1, it is possible to reduce the concentration of efficiently carbonyl sulfide even with high coal content of sulfur component carbonyl sulfide frequently occur. The oxidizing agent O, in particular as long as it can oxidize the raw material is no limitation, for example, oxygen or the like can be used. Incidentally, the gasifier 11 is gasified gas G 1 is not necessarily provided if it is possible to supply to the 1COS transducer 12.
[0023]
　The 1COS converter 12, the presence of a first catalyst, the first predetermined temperature, as shown in the following reaction formula (1), the gasification gas G 1 while the hydrogen cyanide contained in the ammonia, the following reaction formula (2) and as shown in the following reaction formula (3), a first conversion processing to hydrogen sulfide carbonyl sulfide. Further, the 1COS converter 12, the gasification gas G containing ammonia and hydrogen sulfide produced by the first conversion process 2 for supplying the first washing column 13. Such first conversion process, the gasification gas G 1 it is possible to decompose both carbonyl sulfide and hydrogen cyanide contained in the gasification gas G 1 to remove hydrogen cyanide while reducing the concentration of carbonyl sulfide in the be able to. + H
　COS 2 O⇔H 2 S + CO　　2 · · · formula 　(1) HCN + H 2 O⇔NH 3 + CO 　· · · formula 　(2) HCN + 3H 2 ⇔NH 3 + CH 4
　
　　· Formula (3)
[0024]
　As the first catalyst is not particularly limited as long as it can decomposing hydrogen cyanide and carbonyl sulfide, for hydrolysis comprising the active ingredient decomposing carbonyl sulfide and hydrogen cyanide, and titanium oxide carrier carrying the active ingredient catalyst or the like can be used.
[0025]
　The active ingredient, for example, may be used barium, nickel, ruthenium, cobalt, as a main component at least one metal selected from the group consisting of molybdenum. These metals may be used alone or in combination of two or more thereof. By mainly of these metals, can be obtained not only carbonyl sulfide, a high decomposition performance for hydrogen cyanide. Supported amount of the active ingredient, for example, preferably 0.1 wt% to 25 wt% or less, more preferably 22 mass% 1 mass% or more.
[0026]
　Titanium oxide based support, for example, can be formed using a composite oxide of titanium oxide and titanium oxide and other oxides. By using such a titanium oxide-based carrier, it is possible to reliably fix the active ingredient, since it is chemically stable under the conditions of use of the first catalyst, to inhibit the action of the catalyst there is no. Titanium oxide, titanium oxide crystal structure of large anatase specific surface area are preferred. Accordingly, since many supported amount of the active ingredient, thereby improving the catalytic activity. As the composite oxide, for example, include a composite oxide of titanium oxide and silicon oxide, a composite oxide of titanium oxide, aluminum oxide, titanium oxide-based composite oxide and composite oxide of titanium oxide zirconium oxide It is. Combined ratio of the metal oxide composite and titanium oxide, 1:99 to 99: and is preferably 1, 50: 50-95: range of 5 is more preferable. Thus, the specific surface area is a place carrying the active ingredient can be increased, catalytic performance of the first catalyst is improved. By using such a titanium oxide-based composite oxide, the specific surface area of ​​the first catalyst is increased, heat resistance is improved. These titanium oxide-based carrier may be used alone or in combination of two or more thereof.
[0027]
　The titanium oxide-based carrier, barium carbonate, nickel carbonate, ruthenium nitrate, cobalt carbonate, can be added as additives at least one metal salt selected from the group consisting of ammonium molybdate preferred. These additives, since stable under the conditions of use of the first catalyst can be stably used the first catalyst.
[0028]
　The first catalyst is preferably a honeycomb shape. Thus, even in the use environment where such dust coexists, it is possible to prevent clogging and pressure loss of the first catalyst, it is possible to maintain the first catalyst highly active state.
[0029]
　As the first predetermined temperature, preferably 240 ° C. or higher 350 ° C. or less, more preferably 240 ° C. or higher 320 ° C. or less, more preferably a temperature range of 240 ° C. or higher 300 ° C. or less. In such a temperature range, the gasification gas G after the first conversion process 1 with hydrogen cyanide in sufficiently reduced, it becomes possible to decompose the carbonyl sulfide efficiently hydrogen sulfide.
[0030]
　First washing column 13, gasification gas G is first conversion process 2 is contacted washing liquid and gas-liquid gasification gas G 2 with the exception of ammonia in gasification gas G 2 lower the than the first predetermined temperature a first cleaning process of cooling to the second predetermined temperature performed. The first washing column 13, the gasification gas G after the first cleaning process 3 for supplying to the 2COS converter 14. As the cleaning liquid, gasification gas G 2 is not particularly limited as long as it can be cleaned removing ammonia in, for example, it may be used various washing water. In the first cleaning process, the gasification gas G 2 not only washed off ammonia in gasification gas G 2 cooled by the contact with the washing liquid (e.g., 120 ° C. or higher 140 ° C. or less) by the. Such by the first cleaning process gasification gas G 2 together can remove ammonia as the precipitating cause of trace components in, the gasification gas to a temperature suitable for the hydrolysis of carbonyl sulfide in the 2COS converter 14 in the subsequent stage G 2 can be cooled. Incidentally, the gasification gas G after the first cleaning process 2 to the temperature of efficiently second predetermined temperature, gasification gas G between the first washing column 13 and the 2COS converter 14 2The temperature may be provided a heat exchanger for adjusting the second predetermined temperature.
[0031]
　The 2COS converter 14, the presence of a second catalyst, the lower than the first predetermined temperature the second predetermined temperature, as shown in the following reaction formula (1), gasification gas G was first cleaning process 3 in carbonyl sulfide to remaining second conversion process to hydrogen sulfide. Further, the 2COS converter 14, the gasification gas G after the second conversion process 4 supplies the second washing column 15. In the second conversion process, the gasification gas G by the first cleaning process 3 so is cooled to a temperature suitable for the hydrolysis of carbonyl sulfide, the following reaction formula becomes exothermic reaction chemical equilibrium of carbonyl sulfide (1) be advantageous in the hydrolysis reaction, the gasification gas G 3 can be effectively reduce the concentration of carbonyl sulfide in the. + H
　COS 2 O⇔H 2 S + CO　　2 · · · formula (1)
[0032]
　The second catalyst is not particularly limited as long as it can hydrolyze the carbonyl sulfide, for example, for hydrolysis comprising the active ingredient decomposing carbonyl sulfide and hydrogen cyanide, and titanium oxide carrier carrying the active ingredient catalyst or the like can be used. Further, as the second catalyst, it may be used first catalyst and same catalyst. Further, as the second catalyst, it may be used those suitable for hydrolysis of different carbonyl sulfide from the first catalyst. Further, as the second catalyst, it is also possible to use a pellet form.
[0033]
　The second predetermined temperature, preferably 0.99 ° C. or higher 240 ° C. or less, and more preferably the temperature range of 180 ° C. or higher 200 ° C. or less. In such a temperature range, the hydrolysis reaction of carbonyl sulfide proceeds rapidly, since the chemical equilibrium in the above reaction formula (1) is advantageous in the hydrolysis reaction of the carbonyl sulfide, after the second conversion process the gasification gas G 3 and it is possible to sufficiently reduce the carbonyl sulfide concentration in the.
[0034]
　The second washing column 15, gasification gas G is second conversion processing 4 is contacted washing liquid and gas-liquid gasification gas G 4 performs a second cleaning process, except for ammonia and trace components in the. The second cleaning process, the gasification gas G 4 impurities in are washed away. The second washing column 15, the gasification gas G after the second washing process 5 for supplying to the desulfurization tower 16. As the cleaning liquid, gasification gas G 4 is not particularly limited as long as it can be cleaned remove hydrogen sulfide in, for example, it may be used various washing water.
[0035]
　Desulfurization tower 16, the second cleaning process the gas of the gas G 5 is contacted washing liquid and gas-liquid gasification gas G 5 hydrogen sulfide absorbing and removing contained in. Thus, the gasification gas G 5 purified gas G hydrogen sulfide contained in is removed 6 can be obtained. The absorbing liquid is not particularly limited as long as it can absorb hydrogen sulfide, amine-based absorbing solution used for various desulfurization apparatus or the like is used. Desulfurization tower 16, the purified gas G to remove hydrogen sulfide 6 for supplying the gas turbine 17.
[0036]
　Gas turbine 17, the purified gas G supplied from the desulfurization tower 16 6 to generate electric power was combusted with oxygen. Further, the gas turbine 17, the purified gas G 6 combustion exhaust gas G produced by the combustion of 7 to discharge to the outside. Incidentally, the purified gas G 6 is also applicable to various chemicals synthesized in addition to the fuel of the gas turbine 17.
[0037]
　Next, a description will be given of the overall operation of the gas purification unit 1. Gasification gas G feed F is gasified in the gasification furnace 11 1 is supplied to the 1COS transducer 12. In a 1COS converter 12, the gasification gas G 1 is a first predetermined temperature (e.g., 240 ° C. or higher 350 ° C. or less) to the hydrogen cyanide ammonia together with the first conversion processing has been carbonyl sulfide at is hydrolyzed to hydrogen sulfide is decomposed and removed by gasification gas G 2 is supplied to the first washing column 13 as. In the first washing column 13, the gasification gas G 2 is a cleaning liquid and the gas-liquid contact with the first cleaning process with ammonia and a second predetermined temperature with a halogen is washed out (e.g., 240 ° C. or less 0.99 ° C. or higher) is cooled gasification gas G 3 is supplied as to the 2COS converter 14. Here, the gasification gas G after cleaning if necessary 2 a may be heated below 240 ° C. 0.99 ° C. or higher in the heat exchangers. In a 2COS converter 14, the gasification gas G 3 is carbonyl sulfide concentration carbonyl sulfide is hydrolyzed by the second conversion process is gasified gas G which is reduced to a predetermined concentration 4 is supplied to the second washing column 15 as that. In the second washing column 15, the gasification gas G 4 is removed impurities by a second cleaning process of contacting the cleaning solution and gas-liquid and gasification gas G 5It is supplied to the desulfurization tower 16 as. In the desulfurization tower 16, the gasification gas G 5 , the absorption liquid and the gas-liquid contact with hydrogen sulfide purified gas G are removed 6 is supplied to the gas turbine 17 as. Here, the purified gas G hydrogen sulphide has been removed by the desulfurization tower 16 to the gas turbine 17 6 so is supplied, it is possible to prevent corrosion of the gas turbine 17 with hydrogen sulfide. In the gas turbine 17, the purified gas G 6 are being burned with oxygen the combustion exhaust gas G 7 is discharged as.
[0038]
　In the gas purifying apparatus 1 shown in FIG. 1, an example is described in which two wash column of the first washing column 13 and the second washing column 15 may be configured to provide one of the scrubbing column . Figure 2 is a schematic view showing another example of a gas purification unit according to the present embodiment. As shown in FIG. 2, the gas purification unit 2, washing column 18 is provided after the first 1COS transducer 12, desulfurization tower 16 is provided downstream of the 2COS transducer 14. That is, in the gas purification unit 2, washing column 18 is provided instead of the first washing column 13 of the gas purification apparatus 1 shown in FIG. 1, the second washing column 15 is omitted. Between the first 1COS transducer 12 and wash column 18, the gasification gas G 2 may be provided with a heat exchanger for adjusting to the second predetermined temperature. The other configuration is not described because it is similar to the gas purifying apparatus 1 shown in FIG.
[0039]
　In the gas purification device 2, first 1COS converter 12, the gasification gas G 1 gasified gas G was first conversion process 2 for supplying the washing tower 18. Wash column 18, like the first washing column 13 described above, gasification gas G while a cleaning process of contacting the cleaning solution and the gas-liquid 2 for cooling the second treatment temperature. Thus, halogen and gasification gas G 2 such as ammonia to hydrogen cyanide in was decomposed is washed out. The cleaning tower 18, the gasification gas G after the cleaning process 3 for supplying to the 2COS converter 14. The 2COS converter 14, the gasification gas G 3 after reducing the second conversion processing to carbonyl sulfide in the predetermined concentration or less, the gasification gas G 4 is supplied to the desulfurization tower 16 as. Thus even when the structure, gasification gas G by washing tower 18 2 Since hydrogen cyanide have been removed, the gasification gas G 2 can be prevented precipitation of trace components in.
[0040]
　Figure 3 is a schematic view showing another example of a gas purification unit according to the present embodiment. As shown in FIG. 3, the gas purification unit 3, the 2COS converter 14 is provided after the first 1COS transducer 12, cleaning tower 18 is provided downstream of the 2COS transducer 14. That is, in the gas purification unit 3, washing column 18 is provided in place of the second washing column 15 of the gas purification apparatus 1 shown in FIG. 1, the first washing column 13 is omitted. Further, the first 1COS transducer 12 between the first 2COS converter 14, the gasification gas G 2 may be provided with a heat exchanger for adjusting to the second predetermined temperature. The other configuration is not described because it is similar to the gas purifying apparatus 1 shown in FIG.
[0041]
　In the gas purifier 3, the 1COS converter 12, the gasification gas G 1 gasified gas G was first conversion process 2 for supplying to the 2COS converter 14. The 2COS converter 14, the gasification gas G 2 was reduced to a predetermined concentration carbonyl sulfide and by second conversion processing, gasification gas G 4 is supplied to the wash column 18 as. Wash column 18, as in the second washing column 15 described above, the cleaning process of contacting the cleaning solution and gas-liquid. Thus, the gasification gas G 4 such as ammonia and halogen hydrogen cyanide in was decomposed is washed out. The cleaning tower 18, the gasification gas G after the cleaning process 5 for supplying to the desulfurization tower 16. Thus even when the structure, gasification gas G by washing tower 18 4 since hydrogen cyanide have been removed, the gasification gas G 2 can be prevented precipitation of trace components in.
[0042]
　As described above, according to the above embodiment, since a halogen and a 1COS transducer 12 with ammonia, which is the first conversion process is washed out in the first cleaning process, the gasification gas G 2 a first be cooled to a predetermined temperature below the gasification gas G 2 can be prevented precipitation of trace components in. This not only the process of hydrogen cyanide is unnecessary, the gasification gas G and the first conversion process 2 in a state in which cooled to a second predetermined temperature suitable for the second conversion process of the first predetermined temperature below carbonyl sulfide with carbonyl sulfide can second conversion process to hydrogen sulfide, the first conversion and gasification gas G in two stages of the second conversion process 1 so converting the carbonyl sulfide in the hydrogen sulfide, the gasification gas G 1 in carbonyl sulfide concentration it is possible to decrease efficiently to the desired concentration. Accordingly, the gasification gas G 1 even when high carbonyl sulfide concentration in the gasification gas G 1 can be realized gas purification device 1, 2, 3 capable of efficiently reducing carbonyl sulfide concentration in the.
[0043]
(Second Embodiment)
　Next explained is the second embodiment of the present invention. In the following embodiments will be described by focusing on differences from the first embodiment described above, avoid duplication of description. Also the same reference numerals are used to designate elements common to the first embodiment described above. Furthermore, the following embodiments can be implemented in appropriate combination.
[0044]
　Figure 4 is a schematic diagram showing an example of a gas purification unit 4 according to a second embodiment of the present invention.
　As shown in FIG. 4, a gas purification unit 4 according to this embodiment, gasifier feed F and oxidant O is fed (gasification unit) 11, disposed downstream of the gasification furnace 11 hydrogen cyanide converter 21 (hereinafter, referred to as "HCN converter 21") and the first spray tower disposed downstream of the HCN converter 21 (first cleaning unit) 13, provided after the first washing column 13 and carbonyl sulfide converter (second converter) 22 (hereinafter, "COS converter 22") and, second washing column disposed downstream of COS converter 22 (second cleaning unit) 15, a second washing column (second cleaning portion) 15 desulfurizing tower disposed downstream of and a (desulfurization unit) 16. That is, in the gas purification unit 4, HCN converter 21 is provided in place of the first 1COS transducer 12 of the gas purification apparatus 1 shown in FIG. 1, and COS converter 22 is provided in place of the first 2COS converter 14 there.
[0045]
　HCN converter 21, the presence of a first catalyst, the first predetermined temperature, as shown in the following reaction formula (2) and (3), primarily gasification gas G 1 second to hydrogen cyanide contained in the ammonia performing one conversion processing. Here, the first conversion process hydrogen cyanide, also proceeds as a side reaction conversion to hydrogen sulfide carbonyl sulfide represented by the following reaction formula (1). Further, HCN converter 21, the gasification gas G containing ammonia and a small amount of hydrogen sulfide produced by the first conversion processing 8 for supplying the first washing column 13. Such first conversion process, the gasification gas G 1 can be decomposed and removed the hydrogen cyanide contained in the. + H
　COS 2 O⇔H 2 S + CO　　2 · · · formula 　(1) HCN + H 2 O⇔NH 3 + CO 　· · · formula 　(2) HCN + 3H 2 ⇔NH 3 + CH　　4 · · · formula (3)
　
[0046]
　As the first catalyst is not particularly limited as long as it can decomposing hydrogen cyanide, it can be a conventionally known catalyst for hydrogen cyanide decomposition.
[0047]
　As the first predetermined temperature, preferably 240 ° C. or higher 350 ° C. or less, preferably 240 ° C. or higher 320 ° C. or less, and more preferably the temperature range of 240 ° C. or higher 300 ° C. or less. In such a temperature range, the gasification gas G after the first conversion processing 8 it is possible to sufficiently reduce the residual hydrogen cyanide in.
[0048]
　First washing column 13, gasification gas G is first conversion process 8 is contacted washing liquid and gas-liquid gasification gas G 8 gasification gas G with the exception of ammonia in 8 the first cleaning process for cooling the do. The first washing column 13, the gasification gas G after the first cleaning process 3 for supplying a COS converter 22. In the first cleaning process, the gasification gas G 8 not only washed off ammonia in gasification gas G 8 cooled by the contact with the washing liquid (e.g., 100 ° C. or higher 200 ° C. or less) by the. Such first cleaning gasification gas G 8 is possible remove ammonia as the precipitating cause of trace components in gasification gas G to a temperature suitable for the hydrolysis of carbonyl sulfide in the subsequent COS converter 22 8 can be cooled. Incidentally, the gasification gas G after the first cleaning process 3 to the temperature of efficiently second predetermined temperature, gasification gas G between the first washing column 13 and the COS converter 22 3 the temperature of the a heat exchanger for adjusting the second predetermined temperature may be provided.
[0049]
　COS converter 22, the presence of a second catalyst, the lower than the first predetermined temperature the second predetermined temperature, as shown in the following reaction formula (1), gasification gas G was first cleaning process 3 remaining in the carbonyl sulfide to be the second conversion process to hydrogen sulfide. Further, COS converter 22, the gasification gas G after the second conversion process 9 supplies the second washing column 15. In the second conversion process, the gasification gas G by the first cleaning process 3 so is cooled to a temperature suitable for the hydrolysis of carbonyl sulfide, the following reaction formula becomes exothermic reaction chemical equilibrium of carbonyl sulfide (1) be advantageous in the hydrolysis reaction, the gasification gas G 3 can be effectively reduce the concentration of carbonyl sulfide in the. + H
　COS 2 O⇔H 2 S + CO　　2 · · · formula (1)
[0050]
　The second catalyst is not particularly limited as long as it can hydrolyze the carbonyl sulfide, for example, it can be used as the first catalyst identical to the catalyst according to the first embodiment described above. Further, as the second catalyst, it may be used those suitable for hydrolysis of different carbonyl sulfide from the first catalyst. Further, as the second catalyst, it is also possible to use a pellet form.
[0051]
　The second predetermined temperature, preferably 0.99 ° C. or higher 240 ° C. or less, and more preferably the temperature range of 180 ° C. or higher 210 ° C. or less. In such a temperature range, the hydrolysis reaction of carbonyl sulfide proceeds rapidly, since the chemical equilibrium in the above reaction formula (1) is advantageous in the hydrolysis reaction of the carbonyl sulfide, after the second conversion process gasification gas G 9 it is possible to sufficiently reduce the carbonyl sulfide concentration in the.
[0052]
　The second washing column 15, the second conversion processing gasification gas G 9 is contacted washing liquid and gas-liquid gasification gas G 9 performs second cleaning process except hydrogen sulfide in. The second cleaning process, the gasification gas G 9 impurities in are washed away. The second washing column 15, the gasification gas G after the second washing process 5 for supplying to the desulfurization tower 16. The other configuration is not described because it is similar to the gas purifying apparatus 1 shown in FIG.
[0053]
　Next, a description will be given of the overall operation of the gas purification unit 4. Gasification gas G feed F is gasified in the gasification furnace 11 1 is supplied to the HCN converter 21. The HCN converter 21, the gasification gas G 1 is a first predetermined temperature (e.g., 240 ° C. or higher 350 ° C. or less) in the first conversion process has been hydrogen cyanide is removed are decomposed into ammonia gasification gas G 8 as It is supplied to the first washing column 13. In the first washing column 13, the gasification gas G 8 is, the cleaning liquid and the gas-liquid contact with the first cleaning process with ammonia and a second predetermined temperature with a halogen is washed out (e.g., 240 ° C. or less 0.99 ° C. or higher) is cooled gasification gas G 3 is supplied to the COS converter 22 as. The COS converter 22, the gasification gas G 3 is carbonyl sulfide concentration carbonyl sulfide is hydrolyzed gasification gas G is reduced to a predetermined concentration by the second conversion process 9 is supplied to the second washing column 15 as . In the second washing column 15, the gasification gas G 9 are impurities gasification gas G are removed by the second cleaning process of contacting the cleaning solution and gas-liquid 5 is supplied to the desulfurization tower 16 as. In the desulfurization tower 16, the gasification gas G 5 are purified gas absorbing liquid and the gas-liquid contact with hydrogen sulfide has been removed G 6As it supplied to the gas turbine 17. In the gas turbine 17, the purified gas G 6 are being burned with oxygen the combustion exhaust gas G 7 is discharged as.
[0054]
　In the gas purification unit 4 shown in FIG. 4, an example is described in which two wash column of the first washing column 13 and the second washing column 15 may be configured to provide one of the scrubbing column . Figure 5 is a schematic view showing another example of a gas purification unit according to the present embodiment. As shown in FIG. 5, the gas purification unit 5, washing column 18 is provided after the HCN converter 21, desulfurization tower 16 is provided downstream of the COS converter 22. That is, in the gas purification unit 5, washing column 18 is provided instead of the first washing column 13 of the gas purification unit 4 shown in FIG. 4, the second washing column 15 is omitted. Between the HCN converter 21 and wash column 18, the gasification gas G 8 may be provided a heat exchanger for adjusting to a predetermined temperature. The other configuration is not described because it is similar to the gas purification unit 4 shown in FIG.
[0055]
　In the gas purifier 5, HCN converter 21, the gasification gas G 1 gasified gas G and the first conversion processing to a first predetermined temperature 8 supplied to wash tower 18. Wash column 18, like the first washing column 13 described above, gasification gas G while a cleaning process of contacting the cleaning solution and the gas-liquid 8 is cooled to a second treatment temperature. Thus, gasification gas G 8 such as ammonia and halogen hydrogen cyanide in was decomposed is washed out. The cleaning tower 18, the gasification gas G after the cleaning process 3 for supplying a COS converter 22. COS converter 22, gasification gas G at a second predetermined temperature 3 after was second conversion processing, gasification gas G 9 supplied to the desulfurization tower 16 as. Even when configured in this manner, the gasification gas G by washing tower 18 8 Since ammonia have been removed, gasification gas G 8 can prevent the precipitation of trace components in.
[0056]
　Figure 6 is a schematic view showing another example of a gas purification unit according to the present embodiment. As shown in FIG. 6, the gas purification unit 6, COS converter 22 is provided after the HCN converter 21, cleaning tower 18 is provided downstream of the COS converter 22. That is, in the gas purification unit 6, washing column 18 is provided in place of the second washing column 15 of the gas purification unit 4 shown in FIG. 4, the first washing column 13 is omitted. Between the HCN converter 21 and the COS converter 22, the gasification gas G 8 may be provided a heat exchanger for adjusting to a predetermined temperature. The other configuration is not described because it is similar to the gas purification unit 4 shown in FIG.
[0057]
　In the gas purification device 6, HCN converter 21, the gasification gas G 1 gasified gas G and the first conversion processing to a first predetermined temperature 8 supplies a COS converter 22. COS converter 22, the gasification gas G 8 after second conversion processing to a second predetermined temperature, gasification gas G 9 supplied to wash column 18 as. Wash column 18, as in the second washing column 15 described above, the cleaning process of contacting the cleaning solution and gas-liquid. Thus, gasification gas G 8 such as ammonia halogen and hydrogen cyanide in was decomposed is washed out. The cleaning tower 18, the gasification gas G after the cleaning process 5 for supplying to the desulfurization tower 16. Even when configured in this manner, the gasification gas G by washing tower 18 9 since hydrogen cyanide have been removed, gasification gas G 8 can prevent the precipitation of trace components in.
[0058]
　As described above, according to the above embodiment, since such as ammonia, which is the first conversion processing by halogen and HCN converter 21 is washed away in the first washing treatment, gasification gas G 8 first predetermined the be cooled to a temperature below gasification gas G 8 can prevent the precipitation of trace components in. This not only the process of hydrogen cyanide is unnecessary, the gasification gas G and the first conversion processing 8 while cooled to a second predetermined temperature suitable for the second conversion process of the first predetermined temperature below carbonyl sulfide carbonyl sulfide can second conversion process to hydrogen sulfide. Further, in the first conversion processing, it is possible to use selectively degrades the first catalytic hydrogen cyanide relative to carbonyl sulphide, it may also be used different first catalyst and the second catalyst carbonyl sulfide hydrolyze together, it is also possible to reduce the amount of the second catalyst required for the hydrolysis of carbonyl sulfide. Accordingly, the gasification gas G 1 even when high carbonyl sulfide concentration in the gasification gas G 1 can be realized gas purifier 4,5,6 capable of efficiently reducing the carbonyl sulfide concentration in the.
DESCRIPTION OF SYMBOLS
[0059]
　1,2,3,4,5,6 gas purifier
　11 gasifier
　12 first 1COS converter
　13 first spray tower
　14 first 2COS converter
　15 second washing column
　16 desulfurizer
　17 gas turbine
　21 HCN converter
　22 COS converter
　F raw material
　G 1 , G 2 , G 3 , G 4 , G 5 , G 8 , G 9　gasified gas
　G 6　the purified gas
　G 7　flue gas
　O oxidant

WE CLAIM

The presence of a first catalyst, the first predetermined temperature, a first conversion unit which the first conversion processing for the hydrogen cyanide contained in the gas to be treated with ammonia,
　the presence of a second catalyst, than the first predetermined temperature at low second predetermined temperature, and a second converter for a second conversion process for carbonyl sulfide of the treated gas after the first converting process with hydrogen sulfide,
　the gas to be treated into contact cleaning liquid and gas-liquid a cleaning unit for cleaning process of cleaning and removing the ammonia Te,
　a desulfurization unit for absorbing and removing hydrogen sulfide of the treated gas to the gas to be treated after the cleaning process by contacting the absorption liquid and gas-liquid, the gas purification system characterized by comprising.
[Requested item 2]
　The cleaning unit includes a first cleaning unit for the first cleaning process the gas to be treated after the first conversion processing by contacting the cleaning solution and the gas-liquid, the gas to be treated which is the second conversion processing and the washing solution and a second cleaning unit to the second cleaning process by gas-liquid contact, a gas purifying apparatus according to claim 1.
[Requested item 3]
　Raw material to produce the treated gas containing said carbonyl sulfide and gasified, the resulting the gas to be treated with the gasification unit to be supplied to the first converter, according to claim 1 or claim 2 gas purifier.
[Requested item 4]
　Said first conversion unit, and the ammonia the hydrogen cyanide together with a hydrogen sulfide carbonyl sulfide, a gas purifying apparatus according to any one of claims 1 to 3.
[Requested item 5]
　Wherein the first predetermined temperature is 240 ° C. or higher 350 ° C. or less, the gas purifying apparatus according to any one of claims 1 to 4.
[Requested item 6]
　The second predetermined temperature is 0.99 ° C. or higher 240 ° C. or less, the gas purifying apparatus according to any one of claims 1 to 5.
[Requested item 7]
　The presence of a first catalyst, the first predetermined temperature, a first conversion step of the first transformation process of the hydrogen cyanide contained in the gas to be treated with ammonia,
　the presence of a second catalyst, than the first predetermined temperature at low second predetermined temperature, and a second conversion step of the second conversion process for carbonyl sulfide of the treated gas after the first converting process with hydrogen sulfide,
　the gas to be treated into contact cleaning liquid and gas-liquid a cleaning step of cleaning and removing the ammonia Te,
　to include a desulfurization step of removing absorbed hydrogen sulfide of the treated absorbing solution and gas-liquid contact is not the object to be treated gas with a gas washing away the ammonia gas purification method characterized.
[Requested item 8]
　As the cleaning step, a first cleaning step of the first cleaning process the gas to be treated after the first conversion processing by contacting the cleaning solution and the gas-liquid, the second conversion processing by said gas to be treated and the cleaning liquid and a second cleaning step of the second cleaning process by gas-liquid contact, a gas purification method according to claim 7.
[Requested item 9]
　Raw material comprising a gasification process to produce the treated gas containing said carbonyl sulfide and gasified gas purification method according to claim 7 or claim 8.