Abstract:
The speed of coal gas desulfurization is improved and the total size of the apparatus can be made compact. The apparatus comprises a sulfide-ion-producing portion ( 54 ), which reacts with a sulfur compound being supplied by the coal gas and produces sulfide ion S 2−  in molten carbonate. A sulfur compound discharge portion ( 53 ) discharges a sulfur compound produced by a reaction with sulfur discharge gas ( 56 ).

Description:
BACKGROUND OF THE INVENTION 
     1 Field of the Invention 
     The present invention relates to a desulfurization apparatus for coal gas containing sulfur, and an electric power plant using the same. 
     2 Description of the Related Art 
     Among fossil fuels, coal is distributed widely in the world in comparison with oil and natural gas. Fossil fuel reserves are plentiful and are expected to be used in the future for generating electric power. A known method of generating electric power involves pulverizing coal in order to be burned. 
     In view of thermal efficiency and adaptability to the environment, there has been developed a coal gasification compound electric power plant in which coal is gasified. The gasified coal is first desulfurized, burned, and then the burned gas is then fed to a gas turbine and a steam turbine to generate electric power. 
     FIG. 1 is a block diagram of a conventional coal gasification combined electric power plant using a desulfurization apparatus. Electric power plant  21  has coal gasification equipment  22 , gas purification equipment  41 , and compound electric power generating equipment  24 . The coal gasification equipment  22  includes gasification furnaces  27   a  and  27   b , that mix pulverized coal  25  and a gasification agent  26  (normally, oxygen) and perform gasification under predetermined conditions. A gas cooler  28  cools coal gas  11  which is exhausted from the gasification furnace  27   b.    
     The coal gas  11  exhausted from the gas cooler  28  passes through the desulfurization tower  2  within the dry desulfurization apparatus  1 . Thereafter, the gas  11  passes through a filter  29  provided within the scrubbing apparatus  23 . Then, the gas  11  is supplied to the combined electric power generating equipment  24 . 
     The coal gas  11  is burned in a burner  30  provided within the combined electric power generating equipment  24 . The burned gas is supplied to an exhaust heat recovery boiler  33  through a gas turbine  31 . A condenser  36  and a steam turbine  35  are provided in the exhaust heat recovery boiler  33 . 
     Operation of the coal gasification combined electric power plant  21  having the above structure will be described below. The pulverized coal  25  and the gasification agent  26  are mixed. The mixed gas is supplied to the gasification furnace  27   a  which has a high temperature. In the gasification furnace  27   a , a reaction occurs in which carbon is mainly oxidized to carbon dioxide. An inner portion of the gasification furnace  27   b  is under high pressure and a reduction reaction takes place mainly between the carbon dioxide and carbon therein. Carbon monoxide is produced through the reduction reaction. Accordingly, the gasification furnaces  27   a  and  27   b  gasify the coal at a high temperature and a high pressure (which varies according to the gasification method, for example, about 1400° C. and about 2 MPa) so as to produce the coal gas  11 . The produced coal gas  11  is composed of carbon monoxide, hydrogen, carbon dioxide, and water vapor. 
     The coal gas  11  is cooled to a suitable temperature (about 500° C.) in the gas cooler  28 . The cooled coal gas  11  is fed to the desulfurization tower  2  within the gas purification equipment  41 . 
     The desulfurization tower  2  removes H 2 S contained in the coal gas  11 . The coal gas  11  exhausted from the desulfurization tower  2  passes through the filter  29  thereafter. The filter  29  removes dust contained in the coal gas  11 . Accordingly, the desulfurization tower  2  and the filter  29  remove sulfur and fine particles that cause corrosion and abrasion of the gas turbine by passing the coal gas  11  therethrough. 
     The clean coal gas  11  from which sulfur and fine particles are removed is supplied to the combined electric power generating equipment  24 . 
     The clean coal gas  11 , purified in the gas purification equipment  41 , is burned in the burner  30 . The burned combustion gas rotates the gas turbine  31  to generate electric power. Exhaust gas  32  is exhausted from the gas turbine  31  and fed to the exhaust heat recovery boiler  33 . The exhaust heat recovery boiler  33  takes the heat from the exhaust gas  32  so as to produce steam  34 . Steam  34  rotates the steam turbine  35  to generate electric power. The steam  34 , exhausted from the steam turbine  35 , is condensed in the condenser  36 . A part of the condensed steam is fed back to the exhaust heat recovery boiler  33 . The remainder of the condensed steam is fed to the gas cooler  28 . 
     Further, heat recovered from the coal gas  11  in the gas cooler  28  is combined with the steam  34  fed from the exhaust heat recovery boiler  33  fed to the steam turbine  35 . Thereafter, the steam  34  is discharged from the steam turbine  35  and returned to the gas cooler  28  through the condenser  36 . 
     When coal is gasified, most of the sulfur contained in the coal becomes hydrogen sulfide and becomes mixed with the coal gas  11 . A convention desulfurization apparatus for removing the hydrogen sulfide at a high temperature using iron oxide as the desulfurization agent, is the dry desulfurization apparatus  1 . The dry desulfurization apparatus  1  performs desulfurization while keeping the temperature of the coal gas  11  high for as long as possible. The fluid upon which the desulfurization function has been performed is supplied to the compound electric power generating equipment  24 . The dry desulfurization method exhibits excellent thermal efficiency. 
     The structure of the dry desulfurization apparatus  1  will be described below with reference to FIG.  2 . It comprises a desulfurization tower  2 , a regeneration tower  3 , a reduction tower  37 , a sulfur condenser  8 , a circulation gas compressor  9  and a heater  10 . 
     The coal gas  11  flows from an end (the lower portion in the drawing) of the desulfurization tower  2 . The flowing coal gas  11  is mixed with desulfurization agent  38  provided within the desulfurization tower  2 . A chemical reaction between the coal gas  11  and the desulfurization agent  38  occurs according to formula (1). 
     
       
         Fe 2 O 3 +2H 2 S+H 2 →2FeS+3H 2 O  (1) 
       
     
     The coal gas  11  from which the sulfur is removed thereafter flows out from the other end (the upper portion in the drawing) of the desulfurization tower  2 . 
     The desulfurization agent  38  which absorbs the sulfur contained in the coal gas  11 , thus becoming a sulfide, and is fed to an end (the upper end in the drawing) of the regeneration tower  3 . Air  39 , including oxygen, is supplied from the other end (the lower portion in the drawing) of the regeneration tower  3 . A chemical reaction shown in formula (2) occurs between the sulfide and the air within the regeneration tower  3 , so that the sulfide is oxidized. The sulfide can be regenerated by this oxidizing reaction. 
     
       
         4FeS+7O 2 →2Fe 2 O 3 +4SO 2   (2) 
       
     
     The regenerated desulfurization agent  38  is again fed to the desulfurization tower  2  and reused. The desulfurization agent  38  is moved between the desulfurization tower  2  and the regeneration tower  3  by air current transmission. 
     The sulfur removed from the desulfurization agent  38  becomes a sulfurous acid gas in the regeneration tower  3 . That gas is then fed to the reduction tower  37  as a regeneration tower outlet gas  14 . The regeneration tower outlet gas  14  is supplied to an end (the lower portion in the drawing) of the reduction tower  37  and undergoes a chemical reaction (3) with a smokeless coal  40  supplied to the other end (the upper portion in the drawing) of the reduction tower  37 , as shown in the following formula: 
     
       
         2C+2SO 2 →2CO 2 +S 2   (3) 
       
     
     A sulfur steam is produced by the chemical reaction that flows into the sulfur condenser  8  (the upper portion in the drawing). 
     The sulfur steam is cooled within the sulfur condenser  8 . The sulfur steam is condensed by the cooling and discharged to an outer portion of the dry desulfurization apparatus  1  as the chemical element sulfur  16 . 
     The tail gas  17  that flows from the other end (the lower portion in the drawing) of the sulfur condenser  8  is fed to the circulation compressor  9  and the pressure thereof increases. The tail gas  17  discharged from the circulation compressor  9  is fed to the heater  10  and the temperature thereof increases. A portion of the heated tail gas  17  is mixed with the coal gas  11  supplied to the desulfurization tower  2  and is then fed to the desulfurization tower  2 . Some of the tail gas  17  is mixed with air  39  for regeneration and is then fed to the regeneration tower  3 . 
     In the conventional desulfurization apparatus described above and the electric power plant using the same, the following problem has occurred. Since the desulfulrization reaction in tower  2  and the regeneration reaction in regeneration tower  3  involve solid-to-gas reactions, the overall reaction speed is less than that of a wet desulfurization apparatus. Furthermore, the reaction rate of each of the chemical reactions is low. Accordingly, the amount of desulfurization agent  38  required in the desulfurization tower  2  and the regeneration tower  3  is large and so tower  2  and regeneration tower  3  must be large in comparison to those required in a wet desulfurization apparatus. As a result, the dry process is costly. 
     Further, as the amount of desulfurization agent  38  increases and the power required for the air current transmission equipment of the desulfurization agent  38  and the electric power plant increases, the total size of the compound electric power plant using the conventional dry desulfurization apparatus increases. In addition, the power consumed within the electric power plant increases. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a compact and inexpensive desulfurization apparatus. Another object of the invention is to provide an electric power plant in which the temperature of the gas to be processed is not lowered and circulation and regeneration of the desulfurization agent are not required. 
     In order to achieve the above objects in accordance with the invention, there is provided a desulfurization apparatus comprising a sulfide-ion-producing portion which reacts with a sulfur compound to producing sulfide ions; a sulfur compound supply portion disposed at one end of the sulfide-ion-producing portion; and a sulfur compound discharge portion disposed at the other end of the sulfide-ion-producing portion, that discharges the sulfur compound produced by a reaction with the sulfide ions. A plurality of the sulfur compound supply portions and a plurality of the sulfur compound discharge portions are alternately disposed through the sulfide-ion-producing portions, and the flow direction within the sulfur compound supplying portion is different from the flow direction within the sulfur compound discharging portion. 
     Further, in accordance with the invention, there is provided a desulfurization apparatus comprising a sulfide-ion-producing portion having a hollow cylindrical shape, reacting with sulfur compounds and producing sulfide ions; the sulfur compound supplying portion is disposed at the inner or outer side of the cylinder of the sulfide-ion-producing portion; and supplies the sulfur compound to the sulfide-ion-producing portion, and the sulfur compound discharge portion is disposed at the opposite side of the cylinder of the sulfide-ion-producing portion. It discharges the sulfur compounds produced by a reaction with the sulfide ions from the sulfide-ion-producing portion. A plurality of the sulfide-ion-producing portions are provided, and the flow direction of the fluid communicating with the inner side of the sulfide-ion-producing portion is different from the flow direction of the fluid communicating with the outer side of the sulfide-ion-producing portion. 
     Still further, in accordance with the invention, there is provided an electric power plant comprising a sulfide-ion-producing portion reacting with a sulfur compound and producing sulfide ions; a sulfur compound supplying portion is disposed at one end of the sulfide-ion-producing portion; and a sulfur compound discharging portion is disposed at the other end of the sulfide-ion-producing portion which discharges the sulfur compounds produced by a reaction with the sulfide ions. A plurality of the sulfur compound supplying portions and a plurality of the sulfur compound discharging portions are alternately disposed through the sulfide-ion-producing portions in an adjacent manner; the desulfurization apparatus is structured in such a manner that the direction of the fluid within the sulfur compound supplying portion is different from that of the fluid within the sulfur compound discharging portion. An electric power generating apparatus using the fluid discharged from the sulfur compound supplying portion is also taught. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of an electric power plant using a conventional desulfurization apparatus; 
     FIG. 2 is a block diagram of the conventional desulfurization apparatus; 
     FIG. 3 is a perspective view of a first embodiment of the desulfurization apparatus in accordance with this invention; 
     FIG. 4 is a block diagram of an electric power plant using the desulfurization apparatus in accordance with the invention; 
     FIG. 5 is a perspective view of a second embodiment of a desulfurization apparatus in accordance with the invention; 
     FIGS.  6 ( a ) and  6 ( b ) are a front elevational view and a cross sectional view of a third embodiment of a desulfurization apparatus in accordance with the invention; and 
     FIG. 7 is a perspective view of a fourth embodiment of a desulfurization apparatus in accordance with the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments in accordance with the invention will be described below with reference to the drawings. 
     FIG. 3 is a perspective view of a desulfurization apparatus of a preferred embodiment in accordance with the invention. And FIG. 4 is an electric power generating system using the desulfurization apparatus. 
     The coal gasification compound electric power plant  61  (FIG. 4) (an electric power generating system) using the desulfurization apparatus  51  has as its major components the coal gasification equipment  22 , the desulfurization apparatus  51 , a scrubbing apparatus  23 , and a compound electric power generating unit  24  (an electric power generating apparatus). 
     In the coal gasification equipment  22 , at first, coal  25  is supplied to a gasification furnace  27   a  having a high temperature together with a gasification agent (oxygen)  26  and they are mixed. The mixed coal and gasification agent  26  are gasified within the gasification furnace  27   a  at a high temperature and gas pressure, which varies in accordance with the gasification method. One example is an internal temperature of about 1400° C. and an internal pressure of about 2 MPa. 
     The produced coal gas  11  is mainly carbon monoxide, hydrogen, carbon dioxide, and water vapor, and normally contains less than 1% hydrogen sulfide. The coal gas  11  is cooled to a suitable temperature (about 700° C.) in a gas cooler  28 . In the cooled coal gas  55 , solid material is removed by a filter  62 . Thereafter, the coal gas  55  is introduced into the flowing passage  52  in order to be processed in the desulfurization apparatus  51 . 
     In FIG. 3, the desulfurization apparatus  51  is structured such that a flowing passage  52  through which the gas flows in order to be to be processed (the sulfur compound-supply portion) is disposed at one end of the sulfur-moving body  54  having a planar shape (the sulfide-ion-producing portion) and a sulfur discharge gas flowing passage  53  (the sulfur compound discharge portion) is disposed at the other end thereof. 
     The sulfur-moving body  54  (which can be considered as an example of the sulfide-ion-producing portion) in the desulfurization apparatus  51  is shaped as a plate having a thickness of about 1 mm. In this embodiment, the sulfur-moving body  54  includes a molten carbonate which functions as a sulfur-dissolved medium, impregnated into a porous member to which a ceramic such as lithium aluminate is sintered. As the carbonate, one or a mixture of carbonates of alkali metals, such as Li, Na and K, or a mixture of alkali metal carbonate and an alkaline earth element carbonate, such as Mg, Ca, Sr and Ba, is used. 
     When the carbonate is melted at a predetermined temperature (ranging from, for example, 400° C. to 850° C., there is a lot of carbonate ion CO 3   2−  within the solution. Hydrogen sulfide H 2 S contained in the coal gas  55  flows through passage  52  in order to be processed and is absorbed into the molten carbonate. Thereafter, a chemical reaction occurs, as shown by formula (4). 
     
       
         H 2 S+CO 3   2− →H 2 O+CO 2 +S 2−   (4) 
       
     
     The sulfide ion S 2−  produced by the chemical reaction of the formula (4) diffuses through the thickness of the sulfur-moving body  54  within the molten carbonate. The diffused sulfide ion reaches an interface with respect to the sulfur discharge gas  56  flowing through the sulfur discharge gas passage  53  arranged at the back of the sulfur moving-body  54 . 
     The sulfur discharge gas  56  is mainly composed of H 2 O and CO 2 . The flow of the sulfur discharge gas  56  is different from the flow of the coal gas  55 . Concretely speaking, they flow opposite to each other. 
     Accordingly, in the interface between the molten carbonate and the sulfur discharge gas  56 , a chemical reaction occurs, as shown in formula (5), which operates in the reverse direction of the reaction in formula (4). 
     
       
         H 2 S+CO 3   2− ←H 2 O+CO 2 +S 2−   (5) 
       
     
     The produced hydrogen sulfide (a gas phase) is mixed into the sulfur discharge gas  56 . At this time, when the product of the partial pressure of H 2 O and the partial pressure of CO 2  contained in the sulfur discharge gas  56  is larger than the product of the partial pressure of H 2 O and the partial pressure of CO 2  contained in the coal gas  55 , the chemical reaction shown in the formula (5) is promoted. 
     Further, in FIG. 4 the coal gas  55  from which sulfur is removed in the desulfurization apparatus  51  is scrubbed by the scrubbing apparatus  23 . The scrubbed coal gas  55  is supplied to the combined electric power equipment  24 . The coal gas  55  supplied to the burner  30  is burned within the combined electric power generating equipment  24 . The combustion gas rotates the gas turbine  31  and generates electric power while expanding within the gas turbine  31 . 
     After burning, the coal gas  55  is discharged as an exhaust gas  32  from the gas turbine  31 . A portion of the exhaust gas  32  becomes a heat source for generating steam  34  by exhaust heat recovery boiler  33 . The remaining exhaust gas  32  is supplied to the desulfurization apparatus  51  as the sulfur discharge gas  56 . 
     After the heat is recovered by the exhaust heat recovery boiler  33 , the exhaust gas  32  is discharged to an outer portion. The steam  34 , heat-exchanged and produced in the exhaust heat recovery boiler  33 , is fed to the steam turbine  35  to generate electric power. A portion of the steam  34  is discharged from the steam turbine  35  and condensed in the condenser  36 . Then, the condensed steam is again supplied to the exhaust heat recovery boiler  33 . The remaining steam  34  is supplied to the gas cooler  28 . 
     The steam  34  produced by the heat recovered from the coal gas  11  in the gas cooler  28  is fed to the steam turbine  35 . 
     The sulfur discharge gas  56  containing H 2 S produced in the above manner has its sulfur removed in a Claus reactor or in sulfur recovery equipment  63  using a lime plaster process. The gas  56  in which the sulfur has been removed is discharged into ambient air as a clean gas  68  (a tail gas). The removed sulfur is recovered. The gas  68  can be reused as a gas passing through the sulfur discharge gas communication passage  53 . 
     In the present desulfurization apparatus and electric power plants using the same, the chemical reaction shown in formula (4) occurs in the end of passage  52  for the gas to be processed in the sulfur-moving body  54 . Further, the chemical reaction shown in formula (5) occurs in the end of the sulfur discharge gas passage  53  in the sulfur-moving body  54 . Accordingly, hydrogen sulfide continuously moves to the sulfur discharge gas  56  from the coal gas  55  which is flowing through passage  52 , so that the concentration of hydrogen sulfide contained in the sulfur discharge gas becomes higher than the concentration of hydrogen sulfide contained in the coal gas  55 . Therefore, hydrogen sulfide can be efficiently concentrated. 
     Further, the sulfur discharge gas  56  uses the burned exhaust gas  32  flowing out from the gas turbine  31 , so that the partial pressure of H 2 O and CO 2  is higher than the partial pressures of H 2 O and CO 2  in the coal gas  55 . Accordingly, the chemical reaction shown in formula (5) occurs at the end of the sulfur discharge gas passage  53 , and the reaction largely proceeds to the left. Therefore, the concentration of hydrogen sulfide contained in the sulfur discharge gas  56  becomes higher than the concentration of hydrogen sulfide contained in the coal gas  55 , and hydrogen sulfide can be efficiently condensed. 
     Further, when the difference between the temperature of the sulfur discharge gas  56  and the temperature of the coal gas  55  is large, the chemical reaction is promoted and the recovery rate of sulfur is improved. Preferably, when the temperature of the sulfur discharge gas  56  is higher than the temperature of the coal gas  55 , the chemical reaction is promoted, so that the recovery efficiency of sulfur is improved. 
     Still further, since the sulfur-moving body  54  is constituted of a porous member containing a molten carbonate, the carbonate is in a liquid state at operating temperature, so that ions move faster than if the carbonate were in a solid state, thereby improving the reaction efficiency. 
     Furthermore, since the flow direction of the coal gas  55  and the flow direction of the sulfur discharge gas  56  are different from each other, that is, they flow in opposite directions, the concentration of hydrogen sulfide contained in the sulfur discharge gas  56  increases as it flows, so that a sulfur discharge gas  56  containing a high concentration of hydrogen sulfide can be obtained. 
     In the embodiment shown in FIG. 3, directly opposing flows are illustrated. While directly opposing flows may be preferred, the invention is not limited to directly opposing flows. For example the flows may cross or may be set at some other angle relative to each other. 
     Next, the structure and operation of a second embodiment in accordance with the invention will be described below with reference to FIG.  5 . 
     In each of the following embodiments, the same reference numerals are attached to the same elements as those of the first embodiment, and overlapping explanations will be omitted. 
     The key feature of the second embodiment is that the desulfurization apparatus  51  is structured by laminating the sulfur-moving bodies  54  and alternately inserting the passage  52  and the sulfur discharge gas passage  53  therebetween. Accordingly, a lot of sulfide can be efficiently recovered from the coal gas  55 . 
     FIG. 5 is a cross sectional view of the second embodiment of the desulfurization apparatus in accordance with the invention. 
     The passage  52  and the sulfur discharge gas passage  53  are alternately layered along with planar sulfur-moving bodies  54 , thereby constituting the desulfurization apparatus  51 . 
     The flow directions of the coal gas  55  and the sulfur discharge gas  56  are different from each other. That is, they flow in directions opposite to each other. 
     In the second embodiment of the desulfurization apparatus mentioned above, by increasing the reaction area for producing the sulfide ions from the sulfide supplied to the sulfur-moving body  54 , the desulfurization process is performed on a large amount of coal gas  55 , so that the sulfide can be recovered. Further, the desulfurization apparatus  51  can be made compact by layering the sulfur-moving bodies  54 . 
     Next, the structure and operation of a third embodiment in accordance with the invention will be described below with reference to FIGS.  6 ( a ) and  6 ( b ). 
     The key feature of the third embodiment is that the desulfurization apparatus  51  is structured by disposing the sulfur-moving bodies  54  in a honeycomb manner. A lot of sulfide can be efficiently recovered from the coal gas  55 . 
     FIG.  6 ( a ) is a front elevational view of the third embodiment of the desulfurization apparatus in accordance with the invention and FIG.  6 ( b ) is a cross sectional view along a line A—A in FIG.  6 ( a ). 
     The cylindrical sulfur-moving bodies  54  are disposed in a honeycomb manner. A partition plate  64  having an opening portion  61  is provided in one end in a longitudinal direction of the sulfur-moving body  54 . The other end of the sulfur-moving body  54  is closed. A supply manifold  62  for supplying the coal gas  55  to the sulfur-moving body  54  from the opening portion  61  and a recovery manifold  63  for recovering the sulfur discharge gas  56  from the opening portion  61 , are provided in the opening portion  61  end of the sulfur-moving body  54 . 
     That is, a sulphide-ion producing structure is in the form of a grid of intersecting platelike bodies made of the sulphur moving bodies  54  and extending in two transverse directions to define a honeycomb array of gas passages. Sulphur bearing gas manifolds and gas discharge manifolds  55  and  56  are arranged alternatingly and extend at a diagonal to the two transverse directions of the intersecting platelike bodies. The sulphur bearing gas manifolds and the discharge manifolds are arranged such that alternating ones of the gas passages in both of the two transverse directions are connected to the sulphur bearing gas manifolds, while intervening ones of the gas passages in both of the two directions of connected to the gas discharge (recovering) manifolds  63  via the openings  61 . 
     The sulfur discharge gas  56  is discharged from four opening portions  61  adjacent to one opening portion  61  from which the coal gas  55  is supplied. 
     The coal gas  55  supplied from the supply manifold  62  reaches the cylindrical sulfur-moving body  54  from the opening portion  61 . The sulfide ion is produced in the sulfur-moving body  54 . The sulfide is produced by the produced sulfide ion. The produced sulfide is exhausted from the exhaust manifold  63  through the opening portion  61  by the sulfur discharge gas  56 . 
     In the third embodiment of the desulfurization apparatus mentioned above, by increasing the reaction area for producing the sulfide ions in the sulfur-moving body  54 , the desulfurization process is performed on a large amount of coal gas  55 . Accordingly, the sulfide can be efficiently recovered. Further, the desulfurization apparatus  51  can be made compact by layering the sulfur-moving bodies  54 . 
     Next, the structure and operation of a fourth embodiment in accordance with the invention will be described below with reference to FIG.  7 . 
     According to the fourth embodiment, the desulfurization apparatus  51  is structured by disposing the sulfur-moving bodies  54  in a shell tube manner. A lot of sulfide can be efficiently recovered from the coal gas  55  in this way. 
     A plurality of cylindrical sulfur-moving bodies  54  are disposed. A hollow portion of the sulfur-moving body  54  becomes a supply manifold  62  for supplying the coal gas  55  to the sulfur-moving body  54 . Further, a hollow cylindrical recovery manifold  63  for housing a plurality of sulfur-moving bodies  54  therewithin is provided. The recovery manifold  63  recovers the sulfur discharge gas  56  discharged from the sulfur-moving body  54 . 
     A plurality of sulfur-moving bodies  54 , a plurality of supply manifolds  62 , and the recovery manifold  63  are disposed in a shell tube manner. 
     The coal gas  55  supplied from the supply manifold  62  reaches the cylindrical sulfur-moving body  54 . The sulfide ion is produced in the sulfur-moving body  54  as described above. The sulfide thus produced is discharged from the exhaust manifold  63  through the sulfur discharge gas  56 . 
     In this case, the flow direction within the supply manifold  62  and the flow direction within the recovery manifold  63  are opposed to each other. Further, when the diameter of the supply manifold  62  is made small, the concentration of the sulfide contained in the coal gas  55  can be made small. 
     Further, in the case of using the desulfurization apparatus  51  having the above structure for an electric power plant, since the pressure within the supply manifold  62  is higher than the pressure within the recovery manifold  63 , it is suitable to dispose the recovery manifold  63  within the sulfur-moving body  54  and dispose the supply manifold  62  at the outer side of the sulfur-moving body  54 . By making the structure in the above manner, even when the thickness of the sulfur-moving body  54  is thin and the curvature thereof is large, the structure can sufficiently withstand the pressure from the outer portion. 
     In the fourth embodiment of the desulfurization apparatus mentioned above, by increasing the reaction area for producing sulfide ions from the sulfide supplied to the sulfur-moving body  54 , the desulfurization process can be performed on a large amount of coal gas  55 . Further, since the diameter of the supply manifold  62  is made small, the concentration becomes small, so that desulfurization can be efficiently performed. Still further, the desulfurization apparatus  51  can be made compact by disposing a plurality of the sulfur-moving bodies  54  in a shell tube manner. Furthermore, the manufacture thereof can be easily performed. Moreover, the manufacturing cost for the desulfurization apparatus  51  can be reduced. 
     The invention is not limited to the embodiments mentioned above, and can be variously modified and realized in a range within the scope of the invention. For example, it is not necessary to directly use the exhaust gas from the gas turbine for the sulfur discharge gas, and it is possible to use the gas from which the sulfur is removed as the sulfur discharge gas where the desulfurization apparatus and the sulfur recovery equipment are a closed loop. Further, while the desulfurization apparatus can be shaped in a planar manner or a honeycomb manner in order to increase the reaction area, it can also be shaped in a shell tube manner whereby the method of manufacture is simplified and the manufacturing cost is reduced.