JP4496950B2 - Reforming furnace system - Google Patents

Description

The present invention relates to a reforming furnace system using gas turbine exhaust gas, and more particularly to a steam reforming furnace system equipped with a pre-reformer of a production plant for hydrogen, ammonia, methanol, etc. using hydrocarbons of C ₂ or higher as a raw material.

The reforming furnace is used for producing synthesis gas, which is a raw material for producing these products, from a hydrocarbon raw material in a production process of hydrogen, ammonia, methanol and the like. The raw material is preheated and desulfurized after the pressure is increased to the required pressure, heated to about 500 ° C. by heat exchange with steam and the exhaust gas of the reforming furnace, and then filled with the reforming catalyst. The heat is supplied from the reforming furnace combustion gas and reformed into synthesis gas. For example, when reforming under a pressure of about 20 atm, the reforming temperature is 800 ° C. or higher, and therefore a large amount of heating fuel is required.

As a method for saving the heating fuel, for example, as disclosed in Japanese Patent Application Laid-Open No. 06-207531, a reformer and a gas turbine are used together to produce electric power, and the high-temperature exhaust gas from the gas turbine is converted into a reformer. By introducing a pre-reformer upstream of the reforming furnace and reforming the heavy fraction in the raw material to methane in advance. The temperature at the reforming furnace inlet, which has been limited to about 500 ° C. or lower in order to prevent trouble of carbon deposition due to thermal decomposition of the raw material at the reforming furnace inlet, is increased to 550 to 600 ° C. by heat exchange with the reforming furnace exhaust gas. A system for reducing the amount of fuel used in the reforming furnace (hereinafter referred to as a pre-reformer system) has been proposed.

  In Japanese Patent Application Laid-Open No. 06-207531, a part of the high-temperature exhaust gas of the gas turbine provided together is directly introduced into the heating furnace through the exhaust gas flow path, and is used for emergency or emergency use in preparation for an emergency stop of the gas turbine. The air blower is provided so that the air from the air blower can be introduced into the exhaust gas flow path.

  In the conventional configuration of the pre-reformer system, the raw material needs to be desulfurized before being introduced into the pre-reformer, and a preheating furnace is installed to preheat the raw material to a temperature necessary for desulfurization. Although it is necessary to further raise the temperature for the preliminary reforming, the exhaust gas from the reforming furnace is used as a heat source for that purpose. That is, a heating coil is inserted into the convection section of the reforming furnace, and the raw material is heated to a temperature required for the pre-reforming and introduced into the pre-reformer.

Japanese Patent Laid-Open No. 06-207531

  However, in the technique of Japanese Patent Laid-Open No. 06-207531, although the fuel reduction effect of the reforming furnace can be expected, an increase in the amount of combustion exhaust gas in the reforming furnace results in a decrease in the average combustion exhaust gas temperature, and the radiant heat absorption efficiency of the reforming furnace There is a problem that the reforming furnace becomes large in order to reduce the temperature. Further, since the temperature of the gas turbine exhaust gas is as high as 500 to 600 ° C., in order to introduce the high temperature exhaust gas into the reforming furnace, a high temperature exhaust gas duct that can withstand this temperature is required, so that the equipment cost can be increased. In order to reduce as much as possible, it is necessary to install the reforming furnace and the gas turbine close to each other, in which case the degree of freedom of arrangement is limited.

  In the pre-reformer system, a part of the reformer exhaust heat conventionally used for steam generation is recovered as heat for raising the raw material to a temperature suitable for pre-reforming, and pre-reforming There is a problem that the amount of steam generated from the reforming furnace is reduced due to the reduction of the reformer exhaust gas heat quantity itself due to the fuel saving effect of the reforming furnace due to the use of the reactor.

  The object of the present invention is not to increase the size of the reforming furnace, without losing the freedom of installation of the reforming furnace and the gas turbine, and to compensate for the reduction in the amount of steam generated from the reforming furnace. The object is to provide a reforming furnace system with high thermal efficiency.

In the present invention, a gas turbine and an exhaust heat recovery heat exchanger are provided together with a reforming furnace that burns fuel to generate reforming furnace combustion gas and performs reforming using the reforming furnace combustion gas as a heat source , In addition to generating electricity with the turbine, the exhaust gas from the gas turbine is used for preheating the reforming furnace raw material and generating steam for preliminary reforming. Specifically, a waste heat recovery heat exchanger is provided in the downstream flow path of the gas turbine exhaust gas (500 to 600 ° C.), and the raw material is vaporized and desulfurized by exchanging heat between the high-temperature exhaust of the gas turbine and the reforming furnace raw material. The temperature is raised to a temperature suitable for the pre-reforming and further raised to a temperature suitable for the pre-reforming, and the remaining heat of the gas turbine exhaust gas is used to generate and superheat steam necessary for the pre-reforming.

In the present invention, since the high-temperature exhaust gas from the gas turbine is not directly introduced into the reforming furnace, the radiant heat absorption efficiency of the reforming furnace does not decrease, and the effect of enabling fuel saving without increasing the reforming furnace is achieved. In addition, since there is no need to route a high-temperature exhaust gas duct, there is no need to install a gas turbine near the reforming furnace, and there is an effect that the degree of freedom in plant layout planning is high.

  Furthermore, when only the pre-reformer is provided and the fuel in the reforming furnace is reduced, the amount of steam generated from the exhaust heat recovery unit of the reforming furnace is reduced, but the present invention compensates for the decrease and this plant. There is an effect that it becomes possible to supply the necessary power of the self.

The present invention relates to a reforming furnace system using gas turbine exhaust gas, and gas is supplied to a steam reforming furnace system equipped with a pre-reformer of a production plant for hydrogen, ammonia, methanol, etc., using hydrocarbons of C ₂ or higher as a raw material. Power is generated by installing a turbine power generation facility, and fuel in the raw material preheating furnace and steam reforming furnace (hereinafter referred to as the reforming furnace) is saved by using the exhaust gas from the gas turbine as a heat source for the raw material preheating furnace and pre-reforming. Related to the system. Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a first embodiment of the present invention, and shows a case where a prereformer and a gas turbine are provided in a conventional hydrogen production plant using naphtha as a raw material.

  In FIG. 1, fuel 53 is supplied to a gas turbine 7 provided in the reforming furnace 18, and power is generated by a generator 8. The gas turbine exhaust gas passes through a GT exhaust gas duct 27 and an exhaust heat recovery heat exchanger 6. , Discharged from the chimney 17. The GT exhaust gas duct 27 includes a damper 32 and a blower 30.

  The exhaust heat recovery heat exchanger 6 includes a heat exchanger such as a feed water heater 13, an evaporator 15, a steam superheater 16, a raw material preheater 9, a raw material heaters 10 and 11, a brackish water separation drum 14, and an auxiliary combustor 31. Is done.

  In the exhaust heat recovery heat exchanger 6, the raw material preheater 9 and the raw material heaters 10 and 11 exchange heat between the gas turbine exhaust gas and the reforming furnace raw material, and the raw material is desulfurized tower 3 and the preliminary reformer 12 (adiabatic type), respectively. Heat to the temperature required for the operation of the pre-reformer). The gas turbine exhaust gas discharged from the raw material preheater 9 further exchanges heat with the steam superheater 16, the evaporator 15, and the feed water heater 13. Superheated steam 56 is generated by heat exchange in the steam heater 16. The steam 56 is divided into a steam 59 necessary for pre-reformation and a steam 58 necessary for reforming, as necessary, by making up for the deficiency of the superheated steam 57 generated in the reformer exhaust heat recovery unit 23. The raw material gas and the pre-reformed gas are mixed upstream of the raw material heater 10 and the raw material heater 11. When the gas turbine stops unexpectedly, the damper 32 is closed and the blower 30 and the auxiliary combustor 31 are started, so that the operation of the preliminary reformer 12 and the reforming furnace 18 can be continued. It is also possible to burn the auxiliary combustor 31 during operation of the gas turbine and adjust the gas temperature of each part of the exhaust heat recovery heat exchanger 6 according to the required raw material preheating temperature.

  The reforming furnace raw material naphtha 50 is boosted to a necessary pressure by the raw material pump 1 and then added with circulating hydrogen 51 and supplied to the raw material preheater 9. The raw material vaporized by the raw material preheater 9 and further heated to a temperature necessary for desulfurization of the raw material, for example, 380 ° C., is introduced into the desulfurization tower 3. The sulfur content contained in the raw material is converted into hydrogen sulfide in the hydrodesulfurization layer 4 of the desulfurization tower 3, and is adsorbed and removed by the adsorption layer 5 downstream thereof. Since the sulfur content in the raw material becomes poisoning of the reforming catalyst, it needs to be almost completely removed. The raw material from which the sulfur content has been removed is mixed with an amount of steam 59 necessary for pre-reformation, and is heated to a temperature necessary for pre-reformation, for example, about 475 ° C., by exchanging heat with the high-temperature exhaust gas of the gas turbine by the raw material heater 10. And introduced into the pre-reformer 12. The raw material naphtha is all reformed into a mixed gas of methane, hydrogen, carbon monoxide and carbon dioxide by a pre-reforming catalyst.

The pre-reformed gas mainly composed of methane is further mixed with the steam 58 in an amount necessary for reforming and then heated by the raw material heater 11 to heat the raw material in the reforming furnace exhaust heat recovery unit 23 of the reforming furnace 18. The reactor 20 is further heated to 550 to 600 ° C., introduced into the catalyst tube 19 of the reforming furnace 18, and reformed into synthesis gas at 800 to 850 ° C. by heat from the reforming furnace combustion gas. When naphtha is not pre-reformed, the temperature at the catalyst tube inlet is limited to, for example, 500 ° C. or less in order to avoid carbon deposition at the catalyst tube inlet. However, in the case of a pre-reformed gas mainly composed of methane, there is a risk of carbon deposition. 550 without doing
Heating up to 600 ° C is possible. Hydrocarbon steam reforming reaction is an endothermic reaction that occurs at high temperature, fuel is burned in a reforming furnace, and (1) heat for raising the temperature of the raw material to a temperature suitable for the reaction, and ( 2) Utilized as reaction heat, if the temperature of the raw material introduced into the reforming furnace increases, the heat required for (1) decreases, and the amount of fuel used in the reforming furnace can be reduced accordingly. According to this embodiment, the exhaust heat of the gas turbine is not directly introduced into the reforming furnace 18, but is used to raise the reforming furnace introduction temperature of the raw material, so that it is not necessary to route a high-temperature GT exhaust gas duct. Yes, the degree of freedom in arrangement planning is high. The synthesis gas that has exited the catalyst tube at about 800 to 850 ° C. is cooled to a necessary temperature, for example, about 450 to 300 ° C. in the subsequent high-temperature CO reformer by generating steam in the exhaust heat recovery boiler 25, and is directed to the subsequent apparatus. .

  Next, the operation of this embodiment will be described.

For example, in the case of a conventional facility that produces 1.5 million Nm ³ / d hydrogen using naphtha as a raw material, raw material preheating is performed in an independent raw material preheating furnace, and the load is raised to a temperature required for desulfurization of the raw material, for example, 380 ° C. Assuming that the temperature rises to 4.7 × 10 ⁶ kcal / h, for example, to 500 ° C. at the inlet of the catalyst tube 19, the heat load of the raw material heater 20 of the reformer exhaust heat recovery unit 23 is about 10.0 × 10 10. ⁶ kcal / h, the heat load required for reforming of the reforming furnace 18 is about 59.0 × 10 ⁶ kcal / h when the S / C ratio is 5.0, for example, and the required steam amount is about 101 t / h. Degree. The amount of steam generated in the reformer exhaust heat recovery unit 23 and the exhaust heat recovery boiler 25 is assumed to be, for example, a pressure of 36.5 Mpa and a medium pressure steam at a temperature of 330 ° C., and the synthesis gas temperature at the exhaust heat recovery boiler 25 outlet is set to For example, when it is 380 ° C., it is about 114 t / h. Therefore, the amount of steam that can be supplied to the outside is approximately 13 t / h.

For example, when the pre-reformer 12, the gas turbine 7 having an output of about 29 MW, the generator 8 and the exhaust heat recovery heat exchanger 6 are installed in the conventional hydrogen production facility as described above, as shown in FIG. Since the raw material naphtha 50 is reformed into a gas containing methane as a main component by the pre-reformer 12, assuming that the inlet temperature of the catalyst tube 19 is raised to, for example, 600 ° C., the hydrogen production amount is compared with the above-described conventional equipment When reforming to an equal amount, the heat load of the reforming furnace 18 is reduced to 53.7 × 10 ⁶ kcal / h by about 9% from the conventional equipment due to the rise of the catalyst tube inlet temperature. There is an effect that the fuel of the furnace can be saved. As for the required amount of steam, the steam consumption in the pre-reformer increases the steam consumption, but the S / C ratio of the reforming furnace decreases to about 4.5 as a result of the pre-reformation. The amount of steam consumed in the plant is 101 t / h, the same as in the case of conventional equipment.

  Moreover, by obtaining about 29 MW of electric power from the generator 8 connected to the gas turbine, there is an effect of improving the balance by supplying the necessary power in the facility in house and selling the surplus power to the outside.

The naphtha pressurized to the required pressure, for example, about 30 MPa, by the raw material pump 1 enters the raw material preheater 9 at room temperature and is heated to a temperature required for desulfurization, for example, 380 ° C. Therefore, there is no need for the raw material preheating furnace of the conventional equipment, and there is an effect that the amount of fuel there is also reduced. The raw material desulfurized in the desulfurization tower 3 is mixed with, for example, pre-reforming steam 59 having an S / C ratio of 1.6 corresponding to about 32.2 t / h, and a temperature required for pre-reforming in the raw material heater 10, for example, 475. The temperature is raised to about ° C. The raw material heated by the raw material heater 10 is reformed into a gas mainly composed of methane by the pre-reformer 12, and then mixed with about 69.2 t / h of steam 58 necessary for the reforming. . The premixed gas mixed with the water vapor 58 is guided to the raw material heater 11, where it is heated to, for example, about 478 ° C. and then supplied to the reforming furnace exhaust heat recovery unit 23. The raw material heater 20 is further heated to, for example, 600 ° C. by the reforming furnace combustion gas and introduced into the catalyst tube 19 to be reformed. The load ratio between the raw material heater 11 and the raw material heater 20 is optimized according to the actual facility characteristics. The reforming furnace 18 is supplied with fuel 62 and burned to generate high-temperature reforming furnace combustion gas to supply heat for reforming. Further, after the reforming furnace combustion gas is given heat for reforming, it is further exhausted by the reforming furnace exhaust heat recovery unit 23 and discharged from the chimney 26.

On the other hand, the exhaust gas from the gas turbine 7 is introduced into the exhaust heat recovery heat exchanger 6 at about 570 ° C., for example, and the temperature is lowered by sequentially exchanging heat with the raw material gas. Still has a sufficient amount of heat, and further, heat recovery is performed by the steam superheater 16, the evaporator 15 and the feed water heater 13 as an exhaust heat recovery boiler, and a chimney 17 at a temperature of 215 ° C., for example, at the exhaust heat recovery boiler section outlet. To be discharged.

The feed water 55 that has entered the exhaust heat recovery boiler heated side inlet at, for example, a temperature of 125 ° C. is heated to, for example, a temperature of 245 ° C. by the feed water heater 13, and becomes saturated steam at a temperature of, for example, about 245 ° C. Further, a part of the feed water 55 is branched and supplied to the feed water heater 22 of the reforming furnace exhaust heat recovery unit 23 and heated by the exhaust heat of the reforming furnace 18. The feed water heated by the feed water heater 22 is supplied to the exhaust heat recovery boiler 25 via the brackish water separation drum 24. The exhaust heat recovery boiler 25 performs exhaust heat recovery from the high-temperature synthesis gas 61 reformed in the reforming furnace 18 to generate steam. The generated steam is supplied to the brackish water separation drum 24, where the feed water and the steam are separated. The separated steam is superheated by the steam superheater 21 to become superheated steam 57. The saturated steam generated in the evaporator 15 of the exhaust heat recovery heat exchanger 6 is superheated to, for example, 330 ° C. in the steam superheater 16 and used as reforming steam together with the steam 57 generated in the reformer exhaust heat recovery unit 23. Is done. The steam generated in the exhaust heat recovery heat exchanger 6 is about 32.6 t / h 2 and substantially corresponds to the amount of steam necessary for the pre-reformation. On the other hand, the steam generated in the reforming furnace exhaust heat recovery section 23 and the exhaust heat recovery boiler 25 is slightly reduced to about 110 t / h from the conventional equipment due to the reduction of the reforming furnace combustion gas amount. Since the required amount of steam is about 101 t / h, there is an effect of enabling steam supply to the outside of 41.6 t / h 2, which is about 29 t / h higher than before.

  According to the present embodiment, since high-temperature exhaust gas from the gas turbine is not directly introduced into the reforming furnace, the radiant heat absorption efficiency of the reforming furnace is not lowered, and fuel can be saved without enlarging the reforming furnace. In addition, since there is no need to route a high-temperature exhaust gas duct, there is no need to install a gas turbine in the vicinity of the reforming furnace, and there is a high degree of freedom in plant layout planning.

  Furthermore, when only the pre-reformer is provided and the fuel in the reforming furnace is reduced, the amount of steam generated from the exhaust heat recovery unit of the reforming furnace is reduced, but this embodiment compensates for the decrease and this There is an effect that the necessary power of the plant can be supplied by itself. In addition, the fuel consumption of both the preheating furnace and the reforming furnace can be reduced, and depending on the size of the installed gas turbine, steam and electric power can be supplied to the outside. Further, unlike the case where the gas turbine exhaust gas is directly introduced into the reforming furnace, the present invention has an effect that a wide selection of the gas turbine capacity can be made with respect to the reforming furnace capacity.

  A second embodiment of the present invention will be described with reference to FIG. Note that description of parts common to the first embodiment is omitted.

  In this embodiment, as shown in FIG. 2, the exhaust heat recovery heat exchanger 6 of the first embodiment is replaced with a first exhaust heat recovery heat exchanger 28 and exhaust heat as a second exhaust heat recovery heat exchanger. The recovery boiler 29 is divided and installed. The exhaust heat recovery heat exchanger 28 is used for preheating and heating the raw material, and the exhaust heat recovery boiler 29 is used for generating steam. The gas turbine exhaust gas is divided by a damper 32 of the GT exhaust gas duct 27 and a damper 33 installed in the GT exhaust gas duct 34 according to the heat capacity of the exhaust heat recovery heat exchanger 28. Further, the GT exhaust gas duct 27 that is divided into the exhaust heat recovery heat exchanger 28 includes a blower 30, and the exhaust heat recovery heat exchanger 28 includes an auxiliary combustor 31. The GT exhaust gas duct 34 installed as a bypass path of the exhaust heat recovery heat exchanger 28 is connected to the GT exhaust gas duct 36 that supplies exhaust gas that has passed through the exhaust heat recovery heat exchanger 28 to the exhaust heat recovery boiler 29. It is composed.

  The second embodiment has the following effects in addition to the effects described in the first embodiment.

In the second embodiment, during normal operation, about 60% of the gas turbine exhaust gas is sent to the exhaust heat recovery heat exchanger 28 via the first GT exhaust gas duct 27, and the exhaust gas recovered as exhaust heat is recovered as exhaust heat. It is introduced into the exhaust heat recovery boiler 29 via a second GT exhaust gas duct 36 connecting the outlet of the heat exchanger 28 and the exhaust heat recovery boiler 29. The remaining 40% of the gas turbine exhaust gas flows through the second GT exhaust gas duct 36 via the exhaust heat recovery heat exchanger 28 via the third GT exhaust gas duct 34 that bypasses the exhaust heat recovery heat exchanger 28. It joins with the exhaust gas to be introduced and is introduced into the exhaust heat recovery boiler 29. Since the preheating and heating of the raw material require a heat quantity in a relatively high temperature portion of the gas turbine exhaust gas, the exhaust temperature of the exhaust heat recovery heat exchanger 28 is sufficiently high, for example, about 350 ° C., and this retained heat quantity is effectively recovered. The exhaust gas is combined with the remaining 40% of the gas turbine exhaust gas and introduced into the exhaust heat recovery boiler 29. As a result, the amount of steam generated in the exhaust heat recovery boiler 29 is 32.6 t / h, as in the first embodiment.

  In the second embodiment, when the gas turbine stops unexpectedly, the blower 30 and the auxiliary combustor 31 are urgently started and the flow rate adjusting dampers 32 and 33 are closed. The capacity of the blower 30 and the auxiliary combustor 31 may be 60% of those of the first embodiment in accordance with the capacity of the exhaust heat recovery heat exchanger 28 by introducing some preliminary reforming steam from the outside. As a result, even if the gas turbine stops, there is an effect that the operation of the reforming furnace 18 can be continued via the preliminary reformer 12 with less equipment cost and operation cost than in the first embodiment. In addition, there is an effect that a wide selection of gas turbine capacities can be made with respect to the reforming furnace capacity.

  A third embodiment of the present invention will be described with reference to FIG. Note that a description of portions common to the first and second embodiments is omitted.

In this embodiment, the gas turbine high-temperature exhaust gas bypassing the exhaust heat recovery heat exchanger 28 is directly introduced into the exhaust heat recovery boiler 29, and the exhaust gas of the exhaust heat recovery heat exchanger 28 is extracted from the exhaust heat recovery heat exchanger 28. Is introduced into the exhaust heat recovery boiler 29 at a portion (intermediate portion) through which the temperature close to the exhaust gas flows. That is, the second GT exhaust gas duct 36 connects the outlet of the exhaust heat recovery heat exchanger 28 and the exhaust gas passageway of the exhaust heat recovery boiler 29, and the third GT exhaust gas duct 34 connects the outlet of the gas turbine 7 (first The exhaust gas path is configured by connecting the GT exhaust gas duct 27) and the exhaust heat recovery boiler 29 inlet.

The third embodiment has the following effects in addition to the effects described in the first and second embodiments.

In the present embodiment, the high-temperature gas turbine exhaust gas bypassing the exhaust heat recovery heat exchanger 28 and the exhaust gas from the relatively low temperature exhaust heat recovery heat exchanger 28 are not merged in the ducts, but at portions corresponding to the respective temperatures. It is configured to merge. In the present embodiment shown in the figure, the exhaust gas that has passed through the exhaust heat recovery heat exchanger 28 is merged with the gas turbine exhaust gas supplied from the GT exhaust gas duct 34 in the middle of the evaporator 15 of the exhaust heat recovery boiler 29. The exhaust gas converging point in the exhaust heat recovery heat boiler 29 is a hot exhaust gas bypassed by the GT exhaust gas duct 34 (for example, 570).
Is equivalent to the position where the exhaust gas having the same temperature as the exhaust gas from the exhaust heat recovery heat exchanger 28 (for example, 385 ° C.) or having a predetermined temperature difference circulates. The exhaust gas flow path to be joined may be used, and is not limited to the configuration shown in FIG. According to the present embodiment, there is an effect that it is possible to avoid problems such as deformation of the duct due to thermal stress when these temperature differences are large, without changing the steam generation amount.

  A fourth embodiment of the present invention will be described with reference to FIG. Note that a description of portions common to the first, second, and third embodiments is omitted.

In this embodiment, an existing reformer system is added to a gas turbine 7, a generator 8, an exhaust heat recovery heat exchanger 6.
This is an embodiment in the case where the preliminary reformer 12 is additionally provided. The existing reforming furnace system includes a raw material pump 1K, a raw material preheating furnace 2K, a desulfurization tower 3K, a reforming furnace 18K, a brackish water separation drum 24K, an exhaust heat recovery boiler 25K, and a chimney 26K. A reformer heat recovery section 23K including a radiation section including the catalyst tube 19K, a raw material heater 20K, a steam superheater 21K, and a feed water heater 22K is configured.

  The fourth embodiment has the following effects.

Since the gas turbine 7 and the exhaust heat recovery heat exchanger 6 are additionally installed in the existing reformer system, the raw material desulfurization preheating is performed by the raw material preheater 9, so that the existing raw material preheating furnace 2K is not necessary, The fuel 4.7 × 10 ⁶ kcal / h consumed in the raw material preheating furnace 2K is effectively saved. FIG. 4 shows an example in which the existing raw material preheating furnace 2K is removed by additionally installing the gas turbine 7 and the exhaust heat recovery heat exchanger 6, but the existing raw material preheating furnace 2K is left and the preheating of the raw material is performed. You may comprise so that it may carry out by both the preheating furnace 2K and the raw material preheater 9 of the waste heat recovery heat exchanger 6.

  In addition, when the pre-reformer system is applied to the existing reformer, it is necessary to partially modify the heat recovery section of the existing reformer to increase the raw material preheating coil, and to recover the steam from the existing reformer. In the fourth embodiment, the raw material heater 11 is designed so that the raw material can be heated to, for example, 600 ° C. at the outlet of the existing raw material heater 20K without modifying the existing raw material heater 20K. This makes it possible to introduce the pre-reformer system into the existing reforming furnace without modifying the heat recovery section of the existing reforming furnace, although it is necessary to replace the existing reforming catalyst. There is.

  In addition, when the reforming S / C is 5, the amount of steam that can be sent to the outside is about 13 t / h, but the exhaust heat recovery heat exchanger 6 also generates 32.6 t / h of steam. The amount of air sent to the outside can be greatly increased to about 41.6 t / h, and the overall thermal efficiency can be improved by partially stopping the existing boiler.

  In the fourth embodiment, unlike the conventional gas turbine exhaust gas reforming system, the gas turbine exhaust gas is not directly introduced into the existing reforming furnace, so that the reforming furnace main body such as an air duct and a burner of the reforming furnace is not used. There is no need for modification, and as mentioned above, modification of the existing reforming furnace heat recovery section is also unnecessary, so there is an effect of significantly reducing / shortening both the modification cost and the modification time of the plant.

  In addition, because gas turbine exhaust gas is not directly introduced into the existing reforming furnace, there is no restriction on the installation location of new equipment such as a gas turbine and a pre-reformer, and it can be applied to existing equipment that has no space around the existing reforming furnace. There is an effect.

  The second and third embodiments are not limited to the newly installed reforming furnace system, but can be applied to the existing reforming furnace system as the fourth embodiment, and are described in the second and third embodiments. The effect does not change even when applied to an existing reformer system.

1 is a schematic configuration diagram showing a first embodiment of the present invention. The schematic block diagram which shows the 2nd Example of this invention. The schematic block diagram which shows the 3rd Example of this invention. The schematic block diagram which shows the 4th Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Raw material pump, 3 ... Desulfurization tower, 4 ... Hydrodesulfurization layer, 5 ... Adsorption layer, 6 ... Waste heat recovery heat exchanger, 7 ... Gas turbine, 8 ... Generator, 9 ... Raw material preheater, 10, 11 , 20 ... Raw material heater, 12 ... Pre-reformer, 13, 22 ... Feed water heater, 14 ... Steam separator drum, 15 ... Evaporator, 16, 21 ... Steam superheater, 17, 26 ... Chimney, 18 ... Kai Quality furnace, 19 ... catalyst tube, 23 ... reforming furnace exhaust heat recovery section, 24 ... brackish water separation drum, 25,29 ... exhaust heat recovery boiler, 27,34,36 ... GT exhaust gas duct, 28 ... exhaust heat recovery heat exchange 30 ... Blower, 31 ... Auxiliary combustor, 32, 33 damper, 1K ... Existing material pump, 2K ... Existing material preheating furnace, 3K ... Existing desulfurization tower, 18K ... Existing reforming furnace, 19K ... Existing catalyst tube, 20K ... Existing raw material heater, 21K ... Existing steam superheater, 22K ... Existing feed water heater, 23 ... existing reformer exhaust heat recovery section, 24K ... existing steam separation drum, 25K ... existing exhaust heat recovery boiler, 50 ... raw material naphtha, 51 ... circulating hydrogen, 52, 53, 62 ... fuel, 54 ... air, 55 ... water supply 56, 57, 58, 59, 60 ... steam, 61 ... synthesis gas.

Claims (15)

A pre-reformer that generates pre-reformed gas mainly composed of methane from the raw material after desulfurization;
A reforming furnace for generating reforming furnace combustion gas by burning fuel, and reforming the preliminary reforming gas into a synthesis gas mainly composed of hydrogen and carbon monoxide using the reforming furnace combustion gas as a heat source; Reforming furnace system,
A gas turbine,
Using the exhaust heat of the gas turbine, the raw material led to the pre-reformer and the pre-reformed gas supplied from the pre-reformer to the reforming furnace are heated, and the raw material is fed by the pre-reformer. A reformer furnace system provided with an exhaust heat recovery heat exchanger that generates water vapor used for preliminary reforming of the furnace. A pre-reformer that generates pre-reformed gas mainly composed of methane from the raw material after desulfurization;
A reforming furnace for generating reforming furnace combustion gas by burning fuel, and reforming the preliminary reforming gas into a synthesis gas mainly composed of hydrogen and carbon monoxide using the reforming furnace combustion gas as a heat source; Reforming furnace system,
A gas turbine,
An exhaust heat recovery heat exchanger that heats the raw material guided to the pre-reformer and the pre-reformed gas supplied from the pre-reformer to the reforming furnace using the exhaust heat of the gas turbine; A reforming furnace system comprising an exhaust heat recovery heat boiler that generates steam used for preliminary reforming of a raw material in the preliminary reformer. A desulfurization tower for desulfurizing hydrocarbon raw materials;
A pre-reformer that generates pre-reformed gas mainly composed of methane from the raw material after desulfurization;
A reforming furnace for generating reforming furnace combustion gas by burning fuel, and reforming the preliminary reforming gas into a synthesis gas mainly composed of hydrogen and carbon monoxide using the reforming furnace combustion gas as a heat source; Reforming furnace system,
A gas turbine,
Utilizing the exhaust heat of the gas turbine, the raw material to be desulfurized in the desulfurization tower, the desulfurized raw material led to the preliminary reformer, and the preliminary reformed gas supplied from the preliminary reformer to the reforming furnace And a waste heat recovery heat exchanger for generating steam used for pre-reforming of the raw material in the pre-reformer. A first exhaust gas duct for supplying exhaust gas from the gas turbine to the exhaust heat recovery heat exchanger;
A second exhaust gas duct for supplying the exhaust gas from the exhaust heat recovery heat exchanger outlet to the exhaust heat recovery boiler inlet; and a part of the exhaust gas supplied to the exhaust heat recovery heat exchanger is bypassed, and the second exhaust gas The reforming furnace system according to claim 2, further comprising a third exhaust gas duct that joins the exhaust gas flowing through the duct. A first exhaust gas duct for supplying exhaust gas from the gas turbine to the exhaust heat recovery heat exchanger;
A second exhaust gas duct for guiding exhaust gas at the exhaust heat recovery heat exchanger outlet to the exhaust heat recovery boiler;
A third exhaust gas duct that bypasses a part of the exhaust gas supplied to the exhaust heat recovery heat exchanger and supplies the exhaust heat recovery heat boiler to the inlet of the exhaust heat recovery heat boiler is provided, wherein the second exhaust gas duct is the exhaust heat recovery heat exchanger. The exhaust gas passing through the exhaust gas is connected to the exhaust gas guided to the exhaust heat recovery boiler via the third exhaust gas duct so as to be merged in the middle of the exhaust gas flow path of the exhaust heat recovery boiler. The reforming furnace system according to claim 2.   The reforming furnace system according to claim 1, 2 or 3, wherein an auxiliary combustor is installed in the exhaust heat recovery heat exchanger, and a blower for supplying air to the auxiliary combustor is provided.   The reforming furnace system according to claim 4 or 5, wherein a damper for adjusting an exhaust gas flow rate through which each exhaust gas duct is circulated is provided in the first and second exhaust gas ducts. Using the exhaust heat of the gas turbine, the raw material and fuel to be pre-reformed are burned to generate a reforming furnace combustion gas, and the reforming furnace combustion gas is used as a heat source and supplied to the reforming furnace. An exhaust heat recovery heat exchanger for use in a reforming furnace system configured to heat the pre-reformed pre-reformed gas and generate steam used for pre-reforming of the raw material. Using the exhaust heat of the gas turbine, the raw material and fuel to be pre-reformed are burned to generate a reforming furnace combustion gas, and the reforming furnace combustion gas is used as a heat source and supplied to the reforming furnace. A first exhaust heat recovery heat exchanger for heating the pre-reformed pre-reformed gas;
Exhaust heat recovery heat used in a reforming furnace system provided with a second exhaust heat recovery heat exchanger that recovers exhaust heat from exhaust gas of the gas turbine and generates steam used for preliminary reforming of the raw material Exchanger. The raw material and fuel to be pre-reformed are burned to generate a reformer combustion gas, and the pre-reformed pre-reformed gas supplied to the reformer that performs reforming using the reformer combustion gas as a heat source is heated. In addition, a gas turbine used in a reforming furnace system is characterized in that the exhaust heat is used as a heat source for generating steam used for preliminary reforming of the raw material. A raw material preheater for preheating the raw material to be desulfurized;
A desulfurization tower for desulfurizing a hydrocarbon raw material preheated by the raw material preheater;
A reforming method for an existing reforming furnace system comprising a raw material after desulfurization , generating a reforming furnace combustion gas by burning fuel, and reforming using the reforming furnace combustion gas as a heat source. ,
A gas turbine, an exhaust heat recovery heat exchanger that uses the exhaust heat of the gas turbine, and a pre-reformer that generates pre-reformed gas mainly composed of methane from the raw material after desulfurization,
The raw heat to be desulfurized in the desulfurization tower is preheated by the exhaust heat recovery heat exchanger, and the desulfurized raw material led to the prereformer and the preliminary reformer supplied from the prereformer to the reforming furnace. A method for remodeling an existing reforming furnace system, wherein a steam generated by heating a quality gas and recovering exhaust heat is remodeled so as to be used for a pre-reformation of a raw material in the pre-reformer. A raw material preheater for preheating the raw material to be desulfurized;
A desulfurization tower for desulfurizing a hydrocarbon raw material preheated by the raw material preheater;
A reforming method for an existing reforming furnace system comprising a raw material after desulfurization , generating a reforming furnace combustion gas by burning fuel, and reforming using the reforming furnace combustion gas as a heat source. ,
A gas turbine, an exhaust heat recovery heat exchanger and an exhaust heat recovery boiler that use the exhaust heat of the gas turbine, and a pre-reformer that generates pre-reform gas mainly composed of methane from the raw material after desulfurization are added. Set up
The raw heat to be desulfurized in the desulfurization tower is preheated by the exhaust heat recovery heat exchanger, and the desulfurized raw material led to the prereformer and the preliminary reformer supplied from the prereformer to the reforming furnace. A method for remodeling an existing reformer system, wherein a gas is heated and the steam generated by the exhaust heat recovery boiler is remodeled so as to be used for pre-reformation of the raw material by the pre-reformer. A pre-reformer that generates pre-reformed gas mainly composed of methane from the raw material after desulfurization;
A reforming furnace that burns fuel to generate a reforming furnace combustion gas, and reforms the preliminary reforming gas into a synthesis gas mainly composed of hydrogen and carbon monoxide using the reforming furnace combustion gas as a heat source ;
A gas turbine,
An exhaust heat recovery heat exchanger for recovering exhaust heat from the exhaust gas of the gas turbine,
The exhaust heat recovery heat exchanger uses the exhaust heat of the gas turbine to heat the raw material guided to the preliminary reformer and the preliminary reformed gas supplied from the preliminary reformer to the reforming furnace. A method for operating the reforming furnace system is characterized in that steam used for preliminary reforming of the raw material is generated in the preliminary reformer. A pre-reformer that generates pre-reformed gas mainly composed of methane from the raw material after desulfurization;
A reforming furnace that burns fuel to generate a reforming furnace combustion gas, and reforms the preliminary reforming gas into a synthesis gas mainly composed of hydrogen and carbon monoxide using the reforming furnace combustion gas as a heat source ;
A gas turbine,
An exhaust heat recovery heat exchanger and an exhaust heat recovery boiler for recovering exhaust heat from the exhaust gas of the gas turbine, and using the exhaust heat of the gas turbine, the raw material led to the preliminary reformer and the preliminary reforming Heating the preliminary reformed gas supplied from the furnace to the reforming furnace with the exhaust heat recovery heat exchanger, and generating steam with the exhaust heat recovery boiler for the preliminary reforming of the raw material in the preliminary reformer A method of operating a reforming furnace system characterized by the above. A desulfurization tower for desulfurizing hydrocarbon raw materials;
A pre-reformer that generates pre-reformed gas mainly composed of methane from the raw material after desulfurization;
A reforming furnace that burns fuel to generate a reforming furnace combustion gas, and reforms the preliminary reforming gas into a synthesis gas mainly composed of hydrogen and carbon monoxide using the reforming furnace combustion gas as a heat source ;
A gas turbine,
An exhaust heat recovery heat exchanger for recovering exhaust heat from the exhaust gas of the gas turbine,
The exhaust heat recovery heat exchanger preheats the raw material to be desulfurized in the desulfurization tower using the exhaust heat of the gas turbine, and feeds the raw material guided to the preliminary reformer and the preliminary reformer to the reforming furnace. A method for operating a reforming furnace system, wherein the supplied pre-reformed gas is heated and steam used for pre-reforming of a raw material is generated in the pre-reformer.

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