JP6191405B2 - Method and apparatus for raising temperature of gasification gas - Google Patents

Description

  The present invention relates to a method and an apparatus for raising the temperature of a gasification gas generated in a two-column gasification furnace.

  In recent years, development of fluidized bed gasifiers that use gasification raw materials of hydrocarbon resources such as coal, biomass, garbage, sewage sludge, etc., and supply generated gas as combustible gas has been underway. For example, a fluidized bed gasifier forms a fluidized bed by supplying water vapor as a gasifying agent while heating a gasified raw material at 700 ° C. to 900 ° C. with heated fluidized particles such as sand. A gasification gas is produced by gasifying a gasification raw material by heat.

  This fluidized bed gasifier can reduce the cost compared to the method of partial oxidation at a high temperature of 2000 ° C. using oxygen or air. However, the generated gasification gas contains more tar than the method of partial oxidation at high temperature. Therefore, when the gasification gas containing such a large amount of tar is used in the apparatus, if the temperature of the gasification gas decreases, the tar contained in the gasification gas will condense, blockage of piping, failure of equipment used in the system Problems such as catalyst poisoning will occur.

  Then, the gasification gas produced | generated with the fluidized bed gasification apparatus provided the tar reforming furnace downstream, and removed the tar. Here, the gasification gas produced | generated with the fluidized bed gasifier is temperature lower than the temperature required for reforming when it is led to the downstream tar reforming furnace. For this reason, the gasified gas produced by the fluidized bed gasifier is heated by a heat exchanger before reforming to raise the temperature necessary for reforming, or the gasified gas produced by oxygen or air is used. Some of them are burned to raise the temperature to the temperature required for reforming (Patent Document 1).

JP 2004-182903 A

  However, the method of raising the temperature to the temperature required for reforming with a heat exchanger complicates the structure and leads to an increase in cost. Moreover, the method of burning a part of the generated gas and raising the temperature to the temperature required for reforming has reduced the gasified gas efficiency by reducing the generated gasified gas.

  Therefore, the gasification gas temperature raising method and apparatus according to the present invention raises the gasification gas to a temperature required for reforming without newly introducing a heat exchanger and without reducing the gasification gas efficiency. The purpose is to warm.

  The method of raising the temperature of gasification gas in the two-column gasification furnace of the present invention includes: The gas separator is gasified in the presence of water vapor by the particle separator to be separated from, the downcomer to which the fluidized particles separated by the particle separator are guided, and the heat of the fluidized particles guided by the downcomer. A fluidized bed gasification furnace that generates gasified gas, and seals between the particle separator and the downcomer by a sealing means that allows the fluidized particles to move and prevents the gasified gas from moving. The gasification gas pipe generated by the fluidized bed gasification furnace is guided by the gasification gas pipe to the downcomer and directly contacted with the fluidized particles to exchange heat, and is necessary for reforming in the reforming furnace. Is characterized in that leading to the reforming furnace after the temperature was raised every time.

  The fluidized particles separated by the particle separator are preferably introduced into the downcomer from the tangential direction.

  The gasification gas temperature raising apparatus of the present invention includes a fluidized combustion furnace that heats fluidized particles and discharges fluidized particles together with exhaust gas from above, a particle separator that separates fluidized particles heated by the fluidized combustion furnace from exhaust gas, and The gasified raw material is gasified in the presence of water vapor by the downcomer to which the fluidized particles separated by the particle separator are guided and the heat of the fluidized particles guided by the downcommer to generate gasified gas. A fluidized bed gasification furnace. Between the particle separator and the downcomer, a fluidized particle can be moved and a gasification gas can be sealed so that the gasification gas cannot move, and the gasification gas generated in the fluidized bed gasification furnace is reformed. A gasification gas pipe, a part of the flow path of which is the downcomer, and the gasification gas is in direct contact with the fluidized particles by the downcomer to exchange heat, and is reformed in the reforming furnace. It is characterized in that the temperature is raised to a temperature required for quality.

  According to the gasification gas temperature rising method and apparatus of the present invention, the gasification gas is raised to a temperature required for reforming without newly introducing a heat exchanger and without reducing the gasification gas efficiency. Can warm.

It is a schematic block diagram which shows the two-column type gasification furnace to which the temperature rising method and apparatus of gasification gas are applied. It is a figure which shows a mode that a fluid particle is thrown into a downcomer from a tangential direction, and is a II-II arrow line view of FIG.

  Hereinafter, an example of a mode for carrying out the present invention (hereinafter referred to as an example) will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic configuration diagram showing a two-column gasification furnace to which the method and apparatus for raising a gasification gas according to the present invention is applied. FIG. 2 is a view showing a state in which flowing particles are introduced into the downcomer from the tangential direction, and is a view taken along the line II-II in FIG. 1. A gasification gas temperature raising apparatus 1 according to the present invention includes a fluidized combustion furnace 2, a cyclone 3 (particle separator), a downcomer 5, sealing means 6 and 7, a fluidized bed gasification furnace 8, and a gasification. Gas pipe 10, and the temperature is raised to a temperature necessary for reforming gasification gas 23 in reforming furnace 11.

  The fluidized combustion furnace 2 is charged with fluidized particles 13 and char 14 from a fluidized bed gasification furnace 8 through an overflow pipe 12. The fluidized combustion furnace 2 is supplied with air 15 from the lower part, heats the fluidized particles 13 by combustion of the char 14, and discharges the fluidized particles 13 together with the exhaust gas 16 from the upper part. Here, the fluidized particles 13 are, for example, sand, cinnabar, lime, alumina or the like. The exhaust gas 16 containing the fluidized particles 13 is guided to the cyclone 3 through the exhaust gas pipe 17.

  The cyclone 3 separates the fluidized particles 13 heated by the fluidized combustion furnace 2 from the exhaust gas 16. The separated fluidized particles 13 are guided to the downcomer 5 through the U-shaped pipe 18. Further, the exhaust gas 16 from which the fluidized particles 13 are separated is guided to the next step.

  The U-shaped pipe 18 constitutes the sealing means 6 by the fluidized particles 13 stored in the U-shaped pipe 18 and the steam blowing nozzle 22 that blows the steam 21 into the U-shaped pipe 18. Then, the fluidized particles 13 stored in the U-shaped pipe 18 flow when the steam 21 is blown from the steam blowing nozzle 22 and flow down to the downcomer 5 when a predetermined amount is accumulated. This sealing means 6 seals between the cyclone 3 and the downcomer 5 so that the fluidized particles 13 can move and the gasified gas 23 cannot move.

  As shown in FIG. 2, the downcomer 5 is a pipe line having a circular cross section perpendicular to the longitudinal direction. In the downcomer 5, the U-shaped pipe 18 is connected from the tangential direction in the upper part, and the flowing particles 13 are guided. As a result, the fluidized particles 13 are guided to swirl into the flow path of the downcomer 5 and fall while spreading uniformly. The downcomer 5 guides the fluidized particles 13 to the lower U-shaped pipe 20.

  The lower U-shaped pipe 20 is similar to the U-shaped pipe 18 described above, and includes a fluidized particle 13 stored in the lower U-shaped pipe 20 and a steam blowing nozzle 22 that blows water vapor 21 into the lower U-shaped pipe 20. The sealing means 7 is configured. This sealing means 7 seals between the downcomer 5 and the fluidized bed gasification furnace 8 so that the fluidized particles 13 can move and the gasified gas 23 cannot move. Then, the fluidized particles 13 stored in the lower U-shaped pipe 20 flow when the water vapor 21 is blown in, and flow down to the fluidized bed gasification furnace 8 when a predetermined amount of water is stored.

  In the fluidized bed gasification furnace 8, the fluidized particles 13 are guided from the lower U-shaped pipe 20. Further, the fluidized bed gasification furnace 8 includes a diffuser 24 at the lower part. For example, water vapor 21 from the boiler B is supplied to the air diffuser 24 as a gasifying agent. Then, the air diffuser 24 supplies the water vapor 21 to the fluidized bed gasification furnace 8 to fluidize the fluidized particles 13 of the fluidized bed gasification furnace 8 to form the fluidized bed 25.

  The fluidized bed gasification furnace 8 has a raw material supply pipe 26 on one side. The raw material supply pipe 26 supplies a gasified raw material into the fluidized bed gasification furnace 8. The gasification raw material supplied to the fluidized bed gasification furnace 8 receives the heat of the fluidized particles 13 and is gasified in the presence of the water vapor 21 to generate a gasified gas 23. That is, the gasification raw material undergoes an endothermic reaction with the heat of the fluidized bed 25 and the water vapor 21, and is gasified to generate a gasified gas 23.

  The fluidized bed gasification furnace 8 has an overflow pipe 12 on the other side. The overflow pipe 12 guides the fluidized particles 13 and char 14 constituting the fluidized bed 25 to the fluidized combustion furnace 2. Here, the char 14 refers to an unreacted gasification raw material.

  The gasification gas pipe 10 is a flow path that guides the gasification gas 23 generated in the fluidized bed gasification furnace 8 to the reforming furnace 11. The gasified gas pipe 10 includes a flow path 10a that guides the gasified gas 23 from the fluidized bed gasification furnace 8 to the lower side of the downcomer 5, and a downcomer 5 that guides the gasified gas 23 from the lower side to the upper side of the downcomer 5. A flow path 10b, a flow path 10c that leads the gasified gas 23 from the upper side of the downcomer 5 to the cyclone 4, and a flow path 10d that guides the gasified gas 23 from the cyclone 4 to the reforming furnace 11. Has been. That is, in the gasification gas pipe 10, a part of the flow path is the downcomer 5.

  The gasified gas 23 is in direct contact with the fluidized particles 13 falling from the top to the bottom when the downcomer 5 is guided from the bottom to the top among the channels of the gasified gas pipe 10. The temperature is raised to a temperature necessary for heat exchange and reforming in the reforming furnace 11. Here, the heat capacity of the fluidized particles 13 is very large compared to the heat capacity of the gasified gas 23. For this reason, in order to raise the temperature of the gasification gas 23, for example, it is sufficient that the temperature is higher than the gasification gas 23 by about 5 to 10 ° C. The temperature adjustment for raising the temperature to the required temperature is performed by adjusting the amount of the circulating fluidized particles 13.

  Thereafter, the gasified gas 23 is guided to the reforming furnace 11 after the fluidized particles 13 contained in the gasified gas 23 are removed by the cyclone 4. The reforming furnace 11 is a furnace that removes tar from the gasification gas 23. The reforming furnace 11 includes, for example, a catalyst having a honeycomb structure inside, and removes tar from the gasification gas 23 when the temperature becomes higher than the temperature at which the catalyst acts.

  According to the gasification gas temperature rising method and apparatus of the present invention, the gasification gas 23 generated in the fluidized bed gasification furnace 8 is guided to the downcomer 5 and directly contacted with the fluidized particles 13 for heat exchange. It is possible to raise the temperature of the gasification gas 23 to a temperature necessary for reforming without newly introducing a heat exchanger and without reducing the generated gasification gas 23 and reducing the gasification efficiency.

  The sealing means 6 seals the fluidized particles 13 between the cyclone 3 and the downcomer 5 and allows the gasification gas 23 to move, and the sealing means 7 seals the downcomer 5 and the fluidized bed gasification furnace. 8 is sealed so that the fluidized particles 13 can move and the gasified gas 23 cannot move. As a result, the gasified gas 23 heated to the temperature required for reforming is guided to the reforming furnace 11 without flowing back to the fluidized bed gasification furnace 8 or flowing out through the cyclone 3.

  Further, according to the gasification gas temperature raising method and apparatus of the present invention, the gasification gas 23 generated in the fluidized bed gasification furnace 8 is guided to the downcomer 5 and directly brought into contact with the fluidized particles 13. A part of the tar is adhered by the fluidized particles 13, and the tar can be reduced in the flow path of the downcomer 5.

  Further, the fluidized particles 13 separated by the cyclone 3 are thrown into the downcomer 5 from the tangential direction. Thereby, the fluidized particles 13 are guided to swirl into the flow path of the downcomer 5, fall while spreading uniformly, and can efficiently contact the gasified gas 23 to perform heat exchange.

  In addition, the temperature rising method and apparatus of the gasification gas of this invention are not limited only to the above-mentioned Example. For example, although U-shaped piping was demonstrated, it is not limited to this, L-shaped piping may be sufficient.

  Further, the gasified gas 23 is guided to the downcomer 5 so as to be opposed to the fluidized particles 13, but is not limited thereto, and may be flowed so as to be a cocurrent flow.

  Further, the downcomer 5 may be provided with a baffle plate that generates a turbulent flow with respect to the fluid flowing inside, or may be provided with a number of partition plates to form a maze.

  The sealing means 6 seals the fluidized particles 13 between the cyclone 3 and the downcomer 5 and allows the gasification gas 23 to move, and the sealing means 7 seals the downcomer 5 and the fluidized bed gasification furnace. Although the embodiment has been described in which the fluidized particles 13 are movable between 8 and the gasified gas 23 is immovably sealed, the present invention is not limited thereto. Only the sealing means 6 may be used.

  The gasified gas temperature raising method and apparatus of the present invention can be variously modified without departing from the scope of the present invention.

1 Gasification gas heating device 2 Fluidized combustion furnace 3 Cyclone (particle separator)
5 Downcomer 6 Sealing means 7 Sealing means 8 Fluidized bed gasification furnace 10 Gasification gas pipe 11 Reforming furnace 13 Fluidized particles 16 Exhaust gas 17 Exhaust gas pipe 21 Steam 23 Gasification gas 25 Fluidized bed

Claims (3)

A fluidized combustion furnace that heats the fluidized particles and discharges the fluidized particles together with the exhaust gas from above;
A particle separator for separating fluidized particles heated by the fluidized combustion furnace from exhaust gas;
A downcomer to which fluidized particles separated by the particle separator are guided;
A gas in a two-column gasification furnace comprising: a fluidized bed gasification furnace that generates gasification gas by gasifying a gasification raw material in the presence of water vapor by heat of fluidized particles guided by the downcomer A method for raising the temperature of the gas,
Sealing is performed between the particle separator and the downcomer by a sealing means that allows the fluidized particles to move and prevents the gasified gas from moving, and gasifies the gasified gas generated in the fluidized bed gasification furnace. A gas pipe, which is led to the downcomer and directly contacted with the fluidized particles to exchange heat, and after being heated to a temperature necessary for reforming in the reforming furnace, the gas is guided to the reforming furnace Method for increasing the temperature of activated gas.   The method for raising a temperature of a gasification gas according to claim 1, wherein the fluidized particles separated by the particle separator are introduced into the downcomer from a tangential direction. A fluidized combustion furnace that heats the fluidized particles and discharges the fluidized particles together with the exhaust gas from above;
A particle separator for separating fluidized particles heated by the fluidized combustion furnace from exhaust gas;
A downcomer to which fluidized particles separated by the particle separator are guided;
A gas in a two-column gasification furnace comprising: a fluidized bed gasification furnace that generates gasification gas by gasifying a gasification raw material in the presence of water vapor by heat of fluidized particles guided by the downcomer A gasification temperature raising device,
Sealing means for sealing the gas particles between the particle separator and the downcomer so that the fluidized particles can move and the gasification gas cannot move;
A gasification gas generated in the fluidized bed gasification furnace is guided to the reforming furnace, and a gasification gas pipe in which a part of the flow path is the downcomer is provided,
Gasification gas temperature rising device characterized in that gasification gas is heated in direct contact with fluidized particles by the downcomer and heated to a temperature required for reforming in the reforming furnace .

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