JP4862449B2 - Desulfurizer - Google Patents

Description

  The present invention relates to a desulfurizer that removes a sulfur content from a liquid raw material such as kerosene so as to lower it to an allowable concentration or less, and more specifically, desulfurization of raw material such as kerosene led to a fuel processing device in a fuel cell power generation system. It relates to a desulfurizer to be performed.

  The fuel cell used in the energy sector that directly converts the chemical energy of the fuel into electrical energy causes the anode to perform an electrochemical reaction with an oxidant gas that supplies a hydrogen-rich gas as a fuel gas to the anode and a cathode. The hydrogen-rich gas supplied to the anode of the fuel cell is produced from a liquid raw material such as natural gas or kerosene.

  In the case of producing hydrogen-rich gas from liquid raw materials such as natural gas and kerosene, in general, liquid fuel is led to a reformer filled with a reforming catalyst and passed through the reforming catalyst. It is made to react with the endothermic heat from the heating chamber to reform into a hydrogen rich gas.

  Incidentally, it is known that the reforming catalyst filled in the reformer is deteriorated by sulfur poisoning. Therefore, when the liquid raw material such as kerosene is to be reformed by the reformer, a desulfurizer is placed upstream of the reformer, and the liquid raw material such as kerosene is first passed through the desulfurizer, and the liquid raw material such as kerosene Conventionally, the sulfur content is removed so as to reduce it to an allowable concentration or less.

  FIG. 3 shows an example of a desulfurizer that has been proposed so far. The raw material supply pipe b is directed from the upper part to the lower part so as to be in contact with the outer periphery of the desulfurizer main body a filled with the desulfurizing agent. A preheating line c is formed by winding in a spiral shape, and the lower end of the raw material supply line b is connected to the lower end of the desulfurizer body a so that the raw material is introduced into the desulfurizer body a from the lower end. is there. Further, a heating jacket d is attached to the outer peripheral portion of the desulfurizer main body a so as to cover the desulfurizer main body a and the raw material supply pipe b, and an electric heater e and water vapor provided in the heating jacket d are provided. Heat supplied from the pipe f is conducted to the desulfurizer body a and the raw material supply pipe b. Denoted at g is a desulfurization raw material take-out line connected to the top of the desulfurizer body a so as to take out the desulfurized raw material.

  Therefore, before the raw material is supplied into the desulfurizer main body a through the raw material supply line b, the raw material is preheated in the preheating line c so that the preheated raw material is supplied into the desulfurizer main body a. It is.

  The preheating line c is constantly heated by heat from the electric heater e and the steam pipe f of the heating jacket d and heat generated by the desulfurizer body a (see, for example, Patent Document 1).

JP 2004-263118 A

  However, the one described in Patent Document 1 is provided with a heating jacket d on the outer peripheral portion of the desulfurizer body a, and a raw material supply pipe b is disposed inside the heating jacket d to form a preheating line c. In addition, the heating jacket d is provided with an electric heater e and a water vapor pipe f so as to be constantly heated.

  Therefore, the raw material supplied to the inside of the desulfurizer main body a is preheated by the heating jacket d by heat of the electric heater e or the like at the start-up and normal operation, and the electric heater e is always operated. It is necessary to keep it. For this reason, when a desulfurizer is used as a fuel cell power generation system, there is a problem in that auxiliary power increases when the one described in Patent Document 1 is used.

  Therefore, the present invention is to provide a desulfurizer that enables preheating of the raw material supplied to the inside of the desulfurizer by heat exchange with the desulfurized raw material during normal operation so that preheating by the heater can be reduced. To do.

  In order to solve the above-mentioned problems, the present invention provides a desulfurization raw material take-out pipe and a raw material supply pipe in a heat exchangeable arrangement in the central portion of a desulfurizer body in which a catalyst other than the central portion is filled with a catalyst. The raw material supply pipe is communicated with the lower part of the catalyst layer of the desulfurizer body so that the raw material flows through the catalyst layer from the lower part of the catalyst layer, and the raw material desulfurized in the desulfurizer body is The desulfurization raw material take-out pipe is taken out from the pipe, and is further provided with a heating device that applies heat to the intermediate position of the raw material supply pipe or the desulfurizer body. An intubation tube is arranged in the center so as to reach the upper end, and a desulfurizer body having a ring-shaped cylindrical portion is filled with a catalyst upward except for the lower end to form a catalyst layer. Desulfurization raw material take-out pipe and raw material supply arranged inside the intubation so that heat can be exchanged Is inserted into the desulfurizer main body, the raw material supply pipe and the lower end portion in the desulfurizer main body are communicated via the raw material flow pipe, and the raw material desulfurized by flowing through the catalyst layer from the lower end portion of the desulfurizer main body Is removed from the top of the desulfurizer body and then passed through the desulfurization raw material take-out pipe in the desulfurizer main body, and further includes an intermediate position of the raw material supply pipe and a heating device for applying heat to the desulfurizer main body. To do.

  Further, in the above configuration, the desulfurization raw material take-out pipe and the raw material supply pipe arranged so as to be capable of heat exchange are arranged concentrically to form a double pipe structure, and the raw material is preheated by the desulfurization raw material.

  Further, in the above configuration, the desulfurization raw material is taken out from the top of the desulfurizer body through the take-out pipe / catalyst filling port, and a filter is attached to the take-out pipe / catalyst filling port in a replaceable manner. The desulfurization raw material is taken out through the pipe. Further, a gas supply port for catalyst reduction is provided at the lower end of the desulfurizer body, and the reducing gas supplied from the supply port is caused to flow through the catalyst layer.

  Moreover, in the said structure, it comprises so that a desulfurizer main body may be covered with a vacuum vessel, a heat insulation container, or a heat insulating material.

According to the desulfurizer of the present invention, the following excellent effects can be obtained.
(1) A desulfurization raw material take-out pipe and a raw material supply pipe are arranged in the shaft central part of the desulfurizer main body in which the catalyst other than the central part is filled with a catalyst so that heat exchange is possible, and the raw material supply pipe is placed in the desulfurization process. The raw material is allowed to flow through the catalyst layer from below the catalyst layer of the vessel body, and the raw material desulfurized in the desulfurizer body is taken out from the top to pass through the inside of the desulfurized raw material take-out pipe. In addition, it is configured to include a heating device that applies heat to the intermediate position of the raw material supply pipe or the desulfurizer body, and specifically, the inner tube reaches the upper end of the axial center of the cylindrical container. A desulfurizer body that is arranged in a ring-shaped cylindrical part and filled with a catalyst above the bottom excluding the lower end part to form a catalyst layer, which is arranged inside the inner tube of the desulfurizer body so that heat exchange is possible. Insert the raw material take-out pipe and raw material supply pipe into the desulfurizer body, The desulfurizer after the pipe and the lower end portion in the desulfurizer body are communicated with each other through a raw material flow pipe, and the raw material desulfurized by flowing through the catalyst layer from the lower end portion of the desulfurizer body is taken out from the top of the desulfurizer body. It is configured to include a heating device that heats the desulfurizer main body and a position in the middle of the raw material supply pipe so that it passes through the desulfurization raw material take-out pipe in the main body. Can be supplied to the desulfurizer body after being preheated at the heat source, and the difference between the temperature in the desulfurizer body heated by the heat from the heating device can be reduced and the desulfurization capacity can be fully exhibited. In normal operation, heat exchange between the desulfurized raw material and the supplied raw material is performed, so that the heating device in the middle of the raw material supply pipe need not be operated.
(2) Also, with the configuration of (1) above, during normal operation, heat is transferred from the bottom to the top of the catalyst layer in the desulfurizer body, eliminating the need to operate the heating device at the top of the desulfurizer body. become.
(3) According to the above (1) and (2), when used in a fuel cell power generation system, the power of the catcher can be reduced.
(4) The desulfurization raw material take-out pipe and the raw material supply pipe, which are arranged so as to be capable of heat exchange, are arranged concentrically to form a double pipe structure, and the raw material is preheated with the desulfurization raw material so that it is desulfurized and removed Thus, heat exchange between the raw material to be supplied and the raw material to be supplied can be performed more reliably, and during normal operation, it is not necessary to use an apparatus for preheating the raw material to be supplied.
(5) The desulfurization raw material is taken out from the top of the desulfurizer body through the take-out pipe / catalyst filling port, and a filter is attached to the take-out pipe / catalyst filling port so that the desulfurization raw material is passed through the filter. By adopting a structure that flows in the pipe, even if the catalyst is taken out into the take-out pipe when the desulfurized raw material is taken out, it can be collected by a filter, and the catalyst is prevented from flowing out into the desulfurized raw material take-out pipe. It is possible to eliminate the failure of the back pressure holding valve.
(6) A gas supply port for catalyst reduction is provided at the lower end of the desulfurizer body, and a reduction gas supplied from the supply port is made to flow through the catalyst layer, whereby a Ni-based catalyst is added to the catalyst. Even if it is used and oxidized, it can be easily reduced and can be used for a long time.
(7) By setting the desulfurizer body to be covered with a vacuum vessel, a heat insulating vessel or a heat insulating material, it is possible to prevent heat from being generated by a heating device or a raw material to be taken out after being desulfurized.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  1 and 2 show an embodiment of a desulfurizer according to the present invention in which kerosene as a raw material is desulfurized in a liquid phase.

  A desulfurizer body 1 in which an inner tube 3 having a required diameter is arranged from below at the axial center portion of a cylindrical container 2 extending in the vertical direction so that a portion excluding the upper end portion becomes a ring-shaped cylindrical portion 4 to the lower end. Form. A sintered metal plate having narrow holes as a catalyst receiving plate 5 is horizontally attached to the lower end portion of the ring-shaped cylindrical portion 4 of the desulfurizer main body 1, and the catalyst receiving plate in the desulfurizer main body 1 is attached. 5 A packed bed of the catalyst 7 filled from the take-out pipe / catalyst filling port 19 with an open / close lid provided at the top of the desulfurizer body 1 is formed above.

  A desulfurized kerosene take-out pipe 8 and a raw kerosene supply pipe 9 are arranged concentrically on the outside of the inner tube 3 in the axial center portion, and have a double pipe structure as schematically shown in FIG. The double pipes 10 are arranged concentrically, and the upper end side of the heat exchange double pipe 10 is inserted into the desulfurizer body 1 through the upper end surface of the inner insertion pipe 3 and positioned. On the other hand, the lower end side of the heat exchanging double pipe 10 is bent at a position below the desulfurizer body 1 to form a heat exchanging portion 11 heated by an externally installed kerosene preheating heater 12 for start-up. During the normal operation, the raw kerosene 13 flowing in the raw kerosene supply pipe 9 can be preheated by the heat from the kerosene preheating heater 12 in the heat exchanging section 11, and desulfurized kerosene flowing in the desulfurized kerosene outlet pipe 8 during normal operation. 14 and the raw material kerosene 13 flowing in the raw material kerosene supply pipe 9 outside thereof are subjected to heat exchange so that the raw material kerosene 13 is preheated.

  A kerosene supply line 15 to a reformer (not shown) is connected to an outlet side end of the desulfurized kerosene outlet pipe 8 in the heat exchange double pipe 10, and is connected to an outlet side end of the raw material kerosene supply pipe 9 outside. The raw material kerosene introduction line 16 is connected.

  Of the heat exchange double pipe 10 that is inserted and positioned in the desulfurizer body 1, the raw kerosene supply pipe 9 is closed at the upper end, and the upper end of the raw kerosene supply pipe 9 and the catalyst receiver are closed. The lower space 17 of the plate 5 is connected to one or more raw kerosene circulation pipes 18 passing through the catalyst 7, and the raw kerosene 13 passes through the raw kerosene circulation pipe 18 from the top of the raw kerosene supply pipe 9. After passing through the catalyst receiving plate 5 and flowing downward, it passes through the fine holes of the catalyst receiving plate 5 and enters the catalyst packed bed so as to flow upward between the catalysts 7.

  Of the double pipe 10 for heat exchange inserted in the desulfurizer body 1, the desulfurized kerosene outlet pipe 8 is extended upward and is provided at the top of the desulfurizer body 1. The desulfurizer body 1 is taken out through the return port 6. On the other hand, an extraction pipe / catalyst filling port 19 for desulfurized kerosene 14 desulfurized while ascending in the catalyst 7 is connected to the top of the desulfurizer body 1, and the extraction pipe / catalyst filling port 19 is connected to the desulfurization unit. The desulfurized kerosene outlet pipe 8 taken out through the kerosene return port 6 is communicated with a joint 20. A filter 21 for preventing catalyst outflow is installed in the middle of the extraction pipe 19 so that the very fine catalyst 7 flows into the extraction pipe / catalyst filling port 19 together with the desulfurized kerosene 14. The catalyst 7 is collected to prevent the catalyst 7 from flowing into the desulfurized kerosene take-out pipe 8.

  Further, the desulfurizer main body 1 is provided with two upper and lower desulfurizer upper heaters 22 and a lower desulfurizer heater 23 on the outer peripheral portion of the desulfurizer main body 1. 23, and the desulfurizer body 1 is covered with a vacuum vessel, a heat insulating vessel or a heat insulating material 24.

  Reference numeral 25 denotes a supply port for supplying the reducing gas 26 to the space 17 of the desulfurizer body 1.

  Since the desulfurizer of the present invention has the above-described configuration, the desulfurizer body 1 is filled with a Ni-based catalyst 7 that is preferable for desulfurization of kerosene, and then the raw kerosene 13 is caused to flow into the catalyst 7 from atmospheric pressure. Desulfurization is performed at a pressure of 1 MPa and a temperature of 150 to 300 ° C.

  The packed bed of the catalyst 7 filled in the desulfurizer body 1 may be biased on the inner and outer diameter sides of the desulfurizer body 1. For example, when the biased filling to the outer diameter side (outer peripheral side) is performed. The raw kerosene 13 is less likely to flow through the catalyst 7 at that portion, and an efficient desulfurization treatment cannot be performed. Therefore, it is necessary to prevent the drift in the catalyst 7 between the outer diameter of the desulfurizer body 1 and the inner diameter formed by the inner intubation 3.

  Since the present invention has a configuration in which the inner intubation tube 3 is arranged at the axial center of the desulfurizer body 1, the diameter of the inner tube 3 is adjusted to adjust the diameter of the ring-shaped tubular portion 4 inside the desulfurizer body 1. By changing the directional dimension (internal / external thickness), the ratio of the width and height of the catalyst filling portion can be made free from drift in the catalyst 7. As preferable values, the thickness of the catalyst layer in the inner and outer directions is about 10 to 150 mm, and the height of the catalyst layer is about 50 to 1500 mm.

  When the raw material kerosene 13 is supplied to the raw material kerosene supply pipe 9 in the heat exchange double tube 10, the raw material kerosene 13 passes through the heat exchanging section 11 and is raised. At the time of start-up, since the high-temperature desulfurized kerosene has not yet flowed into the desulfurized kerosene take-out pipe 8 of the double tube 10, the raw kerosene 13 is not preheated by the desulfurized kerosene 14. Therefore, the heat exchanging part 11 of the double pipe 10 is heated by the kerosene preheating heater 12 for starting, and the raw material kerosene 13 entering the desulfurizer body 1 is preheated.

  When the desulfurizer body 1 is also activated, the upper and lower heaters 22 and 23 are operated to heat from the outer periphery, and the temperature is set to 150 to 300 ° C. as described above.

  In the desulfurizer body 1 that is started as described above and heated by the upper and lower heaters 22 and 23, the raw kerosene 13 that has been preheated and supplied in advance is fed from the top of the double pipe 10 into the raw kerosene circulation pipe 18. And then released into the space below the catalyst layer. The raw material kerosene 13 released below the catalyst backing plate 5 passes through the fine holes of the sintered metal and enters the layer of the catalyst 7, and flows through the catalyst 7 and rises as shown by the arrows. During this time, the raw kerosene 13 is desulfurized. At this time, since the raw kerosene 13 entering the desulfurizer body 1 is preheated, even if it enters the desulfurizer body 1 heated by the heaters 22 and 23, the temperature difference from the temperature inside the desulfurizer body 1 is increased. Thus, the desulfurization ability of the catalyst 7 can be sufficiently exerted.

  The kerosene desulfurized in the desulfurizer body 1 is taken out from the top of the desulfurizer body 1 to the take-out pipe / catalyst filling port 19, passed through the filter 21 and transferred to the desulfurized kerosene take-out pipe 8 through the joint 20, and desulfurized kerosene. It passes through the inside of the double pipe 10 for heat exchange through the desulfurized kerosene outlet pipe 8 passing through the return port 6. As a result, the raw material kerosene 13 flowing through the raw material kerosene supply pipe 9 outside the double pipe 10 undergoes heat exchange with the desulfurized kerosene 14 flowing through the desulfurized kerosene discharge pipe 8 at the axial center of the double pipe 10. The raw kerosene 13 is preheated by the desulfurized kerosene 14 and supplied into the desulfurizer body 1.

  Accordingly, when the desulfurizer of the present invention is in a normal operation state, the startup kerosene preheater heater 12 installed at the lower position of the desulfurizer body 1 is not used, so the operation is stopped. I will let you.

  In addition, when the desulfurizer of the present invention is in a normal operation state, in the catalyst layer in the desulfurizer body 1, heat is transferred from the lower side to the upper side, so that only the lower system heater 23 may be used. The heater 22 does not need to be operated.

  As described above, the kerosene preheating heater 12 and the desulfurizer upper heater 22 provided outside are not required to operate during normal operation. Therefore, the auxiliary power when the desulfurizer of the present invention is applied to the fuel cell power generation system. There is an advantage that can be reduced.

  The desulfurized kerosene 14 that has been desulfurized in the desulfurizer body 1 as described above and taken out through the desulfurized kerosene discharge pipe 8 while exchanging heat with the raw kerosene 13 supplied to the desulfurizer body 1 is supplied from the kerosene supply line 15. It is supplied to a reformer (not shown).

  In the above, since the catalyst 7 in the desulfurizer body 1 uses a Ni-based catalyst for kerosene desulfurization, it is inevitable to oxidize. Therefore, it is necessary to reduce the oxidized catalyst 7, and at the time of catalytic reduction, with the supply of the raw kerosene 13 stopped, the raw kerosene in the desulfurization body 1 is extracted and a large amount of reducing gas 26 such as nitrogen is supplied. The desulfurizer body 1 is supplied from the port 25. The reducing gas 26 supplied into the desulfurizer body 1 passes through the pores of the catalyst receiving plate 5 and enters the catalyst 7, and the filter 21 and the desulfurized kerosene discharge pipe 8 from the take-out pipe 19 at the top of the desulfurizer body 1. The flow is discharged after passing through and the catalyst is reduced.

  In the operation of the desulfurizer of the present invention, degassing of the desulfurizer body 1 when the raw kerosene 13 is supplied and filled into the desulfurizer body 1 is performed by opening the cover of the extraction pipe / catalyst filling port 19. Further, when kerosene desulfurized while flowing through the catalyst layer in the desulfurizer body 1 is taken out to the take-out pipe / catalyst filling port 19 at the top of the desulfurizer body 1, the fine catalyst 7 is also one. However, since the filter 21 is installed, the catalyst 7 is captured by the filter 21 and the outflow is prevented. The mesh diameter of the filter 21 is about 10 to 200 μm. When a large amount of gas is allowed to flow as in the catalytic reduction, the filter 21 having a large mesh diameter is used. Therefore, the filter 21 can be easily replaced.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the desulfurizer of the present invention has been described as performing desulfurization using kerosene as a raw material. May be used for desulfurization of natural gas or the like in addition to kerosene, and in FIG. 1, as the heater for heating the desulfurizer, an upper heater 22 and a lower heater 23 are used as upper and lower systems. However, three or more heaters may be provided in the vertical direction. In this case as well, only the heaters of the lower system may be operated during normal operation. Further, as the catalyst 7, when the raw material is kerosene, Although a case where a Ni-based catalyst is used as preferred is shown, a preferred catalyst may be used according to the raw material, and the fluid flowing inside and outside the double tube 10 for heat exchange is replaced. Even It can of course be variously modified within the scope not departing from the gist of the other present invention.

It is a schematic diagram which shows an example of implementation of the desulfurizer of this invention. It is a schematic sectional drawing from the II-II direction of FIG. It is an example figure of the conventional desulfurizer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Desulfurizer main body 3 Inner intubation 4 Cylindrical part 5 Catalyst receiving plate 7 Catalyst 8 Desulfurization kerosene extraction pipe (desulfurization raw material extraction pipe)
9 Raw material kerosene supply pipe (raw material supply pipe)
10 Double tube for heat exchange 11 Heat exchange part 12 Kerosene preheating heater (heating device)
13 Raw material kerosene (raw material)
14 Desulfurization kerosene (desulfurization raw material)
18 Raw material kerosene distribution pipe (raw material distribution pipe)
19 Take-out pipe / catalyst filling port 21 Filter 22 Desulfurizer upper heater (heating device)
23 Desulfurizer lower heater (heating device)
25 Supply port 26 Reducing gas

Claims (7)

  A desulfurization raw material take-out pipe and a raw material supply pipe are arranged on the shaft central part of the desulfurizer main body, in which the catalyst other than the shaft central part is filled with a catalyst, and the raw material supply pipe is connected to the desulfurizer main body. The lower part of the catalyst layer communicates with the raw material to flow through the catalyst layer from the lower part of the catalyst layer, and the raw material desulfurized in the desulfurizer body can be taken out from the top and taken out through the desulfurized raw material take-out pipe. And a desulfurizer comprising a heating device for applying heat to a midway position of the raw material supply pipe.   A desulfurization raw material take-out pipe and a raw material supply pipe are arranged on the shaft central part of the desulfurizer main body, in which the catalyst other than the shaft central part is filled with a catalyst, and the raw material supply pipe is connected to the desulfurizer main body. The lower part of the catalyst layer communicates with the raw material to flow through the catalyst layer from the lower part of the catalyst layer, and the raw material desulfurized in the desulfurizer body can be taken out from the top and taken out through the desulfurized raw material take-out pipe. And a desulfurizer comprising a heating device for applying heat to the desulfurizer body.   A desulfurizer body is formed in a ring-shaped cylindrical portion by placing an intubation tube at the axial center of the cylindrical container so as to reach the upper end portion. Insert the desulfurization raw material take-out pipe and raw material supply pipe, which are arranged inside the inner pipe of the vessel main body so as to allow heat exchange, into the desulfurizer main body, and connect the raw material supply pipe and the lower end of the desulfurizer main body to the raw material distribution pipe. And the raw material desulfurized by flowing through the catalyst layer from the lower end of the desulfurizer body is taken out from the top of the desulfurizer main body and then passed through the desulfurized raw material take-out pipe in the desulfurizer main body. A desulfurizer having a configuration including a midway position of a raw material supply pipe and a heating device for applying heat to a desulfurizer body.   The desulfurizer according to claim 1, 2 or 3, wherein the desulfurization raw material take-out pipe and the raw material supply pipe arranged so as to be capable of heat exchange are arranged concentrically to form a double pipe structure, and the raw material is preheated by the desulfurization raw material.   A desulfurization raw material is taken out from the top of the desulfurizer main body through the take-out pipe / catalyst filling port, and a filter is attached to the take-out pipe / catalyst filling port in a replaceable manner, and the desulfurization raw material that has passed through the filter flows into the desulfurization raw material take-out pipe The desulfurizer according to claim 1, 2, 3, or 4.   6. The desulfurizer according to claim 1, wherein a gas supply port for catalyst reduction is provided at a lower end portion of the desulfurizer main body, and a reducing gas supplied from the supply port is caused to flow through the catalyst layer.   The desulfurizer of Claim 1, 2, 3, 4, 5 or 6 comprised so that a desulfurizer main body might be covered with a vacuum vessel, a heat insulation container, or a heat insulating material.

Images