Biomass gasification furnace, liquid fuel manufacturing facility, and operation method of biomass gasification furnace

Abstract

To provide a biomass gasification furnace capable of achieving favorable combustion or thermal decomposition in a gasification furnace body.SOLUTION: A biomass gasification furnace comprises: a gasification furnace body 11 that gasifies a biomass feedstock; a biomass feedstock input part 22 that feeds the biomass feedstock into the gasification furnace body 11; a steam input pipe 17 that is provided in a second cylindrical part 11e below the biomass feedstock input part 22, and supplies a gasifying agent into the gasification furnace body 11; and a tar removal facility that adsorbs tar from a product gas generated in the gasification furnace body 11 with an adsorbent and removes it, wherein the tar removal facility comprises a tar-containing steam discharge part that discharges tar-containing steam generated when regenerating the adsorbent by desorbing the tar adsorbed to the adsorbent with steam, and a tar-containing steam supply pipe 20 is provided to supply the tar-containing steam guided from the tar-containing steam discharge part to the second cylindrical part 11e.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a biomass gasification furnace, a liquid fuel production facility, and an operation method of a biomass gasification furnace.

Background Art

[0002] As a gasification technology using a biomass gasification furnace, a jet fluidized bed type is known. The jet fluidized bed type has a feature that the amount of tar generated is low because the gasification temperature is higher than that of the fluidized bed type. (The tar mentioned here means an organic compound (PAH: Polycyclic Aromatic Hydrocarbons) in which the carbon content contained in the biomass raw material cannot be completely converted into low molecular components such as CO and CH4 in the gasification furnace and remains as a polycyclic aromatic hydrocarbon).

[0003] However, when producing synthetic fuels such as SAF (Sustainable Aviation Fuel) by combining a gasification furnace with a synthesis facility using the Fischer-Tropsch method or the like, the tar generated in the gasification furnace becomes a poisoning component of the catalyst of the synthesis facility. Therefore, even in the case of a jet fluidized bed type gasification furnace, it is necessary to remove tar upstream of the synthesis facility.

[0004] As a tar removal method, scrubbers and adsorption towers are known. However, since the scrubber has a large replacement cost of the scrubber liquid and is not suitable for high-purity purification (removing tar to the required value of the synthesis facility), an adsorption tower is often applied.

[0005] Adsorption towers are roughly classified into non-regenerative type and regenerative type. In the non-regenerative type, when the adsorbent adsorbs more than a predetermined amount of tar and breakthrough occurs, the required removal performance cannot be ensured from the downstream, so the adsorbent needs to be replaced periodically, which has a great impact on the running cost.

[0006] The regenerative adsorption tower has, for example, an adsorption step of adsorbing tar onto the adsorbent, a regeneration step of supplying steam to desorb the adsorbed tar from the activated carbon for regeneration, and a standby step of waiting for the next adsorption step.

[0007] By using the above-mentioned regenerative adsorption tower to repeatedly use the adsorbent, it is possible to reduce the replenishment amount of the new adsorbent and significantly reduce the running cost.

[0008] On the other hand, in the process of cooling the tar discharged to the outside of the system together with steam in the regeneration step, there is a concern that a highly viscous slurry substance is formed by the condensed and solidified tar. As a result, the slurry substance may adhere and grow on the heat transfer surface of the cooler and in the subsequent pipes, leading to a decrease in the heat transfer performance of the cooler and blockage in the cooler and pipes. The over-design of the equipment size (heat transfer area) of the cooler or the adverse effects of stable operation have become problems in the conventional process.

[0009] In addition, since tar has a certain calorific value, discharging it directly to the outside of the system results in heat loss (unburned loss) for the plant and becomes one of the factors causing a decrease in thermal efficiency. Furthermore, although the steam used for the regeneration of activated carbon retains a certain enthalpy even after regeneration, it is exhausted to the outside of the system and causes heat loss.

[0010] Patent Document 1 discloses supplying the tar-containing steam subjected to regeneration treatment in an activated carbon adsorption tower to a gasification furnace.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0012] However, as a result of intensive studies by the inventors, it has been found that when the tar-containing steam after desorbing tar from the adsorbent is introduced into the gasification furnace body, the tar-containing steam has an adverse effect on the combustion or pyrolysis state in the gasification furnace body.

[0013] For example, when the temperature of the tar-containing steam is less than the desired temperature, if the tar-containing steam is supplied to the gasification furnace body, there is a risk that the combustion temperature or pyrolysis temperature in the gasification furnace body will decrease and the desired combustion or pyrolysis cannot be achieved.

[0014] Also, in the case of a fluidized bed type gasification furnace, it is designed to maintain a desired superficial velocity in the combustion section etc. depending on the flow rate of the steam (gasifying agent) introduced into the gasification furnace body. However, if tar-containing steam is additionally introduced, there is a risk that the desired superficial velocity cannot be maintained depending on the position where the tar-containing steam is additionally introduced.

[0015] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a biomass gasification furnace, a liquid fuel production facility, and an operation method of a biomass gasification furnace that can achieve good combustion or pyrolysis in the gasification furnace body.

Means for Solving the Problems

[0016] A biomass gasification furnace according to an aspect of the present disclosure includes a gasification furnace body that gasifies a biomass raw material, a biomass raw material input unit that inputs the biomass raw material into the interior of the gasification furnace body, a gasifying agent input unit that is provided in a lower region below the biomass raw material input unit and inputs a gasifying agent into the interior of the gasification furnace body, and a tar removal facility that adsorbs and removes tar from the product gas generated in the gasification furnace body with an adsorbent. The tar removal facility includes a tar-containing steam discharge unit that discharges the tar-containing steam generated when the tar adsorbed on the adsorbent is desorbed by steam to regenerate the adsorbent, and a tar-containing steam supply pipe that supplies the tar-containing steam led from the tar-containing steam discharge unit to the lower region is provided.

[0017] A biomass gasification furnace according to one aspect of the present disclosure includes a gasification furnace body for gasifying a biomass raw material, a biomass raw material input section for introducing the biomass raw material into the interior of the gasification furnace body, a gasifying agent input section provided in a lower region below the biomass raw material input section for introducing a gasifying agent into the interior of the gasification furnace body, a product gas cooler for cooling the product gas generated in the gasification furnace body, and a tar removal facility for adsorbing and removing tar from the product gas led from the product gas cooler with an adsorbent. The tar removal facility includes a tar-containing water vapor discharge section for discharging the tar-containing water vapor generated when the tar adsorbed on the adsorbent is desorbed by steam to regenerate the adsorbent. The tar removal facility includes a tar-containing water vapor supply pipe for guiding the tar-containing water vapor led from the tar-containing water vapor discharge section. The tar-containing water vapor supply pipe is connected to the gasification furnace body through a cooling medium flow path of the product gas cooler.

[0018] A biomass gasification furnace according to one aspect of the present disclosure includes a gasification furnace body for gasifying a biomass raw material, a biomass raw material input section for introducing the biomass raw material into the interior of the gasification furnace body, a gasifying agent input section provided in a lower region below the biomass raw material input section for introducing a gasifying agent into the interior of the gasification furnace body, and a tar removal facility for adsorbing and removing tar from the product gas generated in the gasification furnace body with an adsorbent. The tar removal facility includes a tar-containing water vapor discharge section for discharging the tar-containing water vapor generated when the tar adsorbed on the adsorbent is desorbed by steam to regenerate the adsorbent. The tar removal facility includes a tar-containing water vapor supply pipe for guiding the tar-containing water vapor led from the tar-containing water vapor discharge section. The biomass gasification furnace according to one aspect of the present disclosure includes a control section for controlling the amount of steam introduced into the gasification furnace body according to the amount of tar-containing water vapor supplied from the tar-containing water vapor supply pipe to the gasification furnace body.

[0019] A liquid fuel production facility according to one aspect of the present disclosure includes the biomass gasification furnace described in any one of the above aspects and a liquid fuel synthesis facility for synthesizing a liquid fuel from at least a part of the product gas generated in the gasification furnace body.

[0020] The operation method of a biomass gasification furnace according to an aspect of the present disclosure includes a gasification furnace body for gasifying biomass raw materials, a biomass raw material input section for inputting biomass raw materials into the interior of the gasification furnace body, a gasifying agent input section provided in a lower region below the biomass raw material input section for inputting a gasifying agent into the interior of the gasification furnace body, and a tar removal facility for adsorbing and removing tar from the product gas generated in the gasification furnace body with an adsorbent. The operation method of the biomass gasification furnace is such that the tar removal facility includes a tar-containing water vapor discharge section for discharging tar-containing water vapor generated when the tar adsorbed on the adsorbent is desorbed by steam to regenerate the adsorbent, and the tar-containing water vapor led from the tar-containing water vapor discharge section is supplied to the lower region.

Effect of the Invention

[0021] Good combustion or pyrolysis in the gasification furnace body can be realized.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0023] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 shows a liquid fuel production facility 1 according to this embodiment.

[0024] The liquid fuel manufacturing facility 1 includes a biomass gasification furnace 3 and an FT synthesis facility (liquid fuel synthesis facility) 5 using the Fischer-Tropsch method.

[0025] The biomass gasification furnace 3 includes a gasification furnace main body 11, an SGC (Syn Gas Cooler: synthesis gas cooler) 12, a dust collection device 13, a gas purification facility 14, and a tar removal facility 15.

[0026] The gasification furnace main body 11 uses oxygen and steam as gasifying agents. The gasification furnace main body 11 is of the entrained flow type and generates synthesis gas (producer gas) from biomass raw materials. Biomass raw materials pulverized into fine particles by a mill (not shown) are fed into the gasification furnace main body 11. As the biomass raw materials, for example, thinned wood, waste wood, driftwood, bark, paper sludge, agricultural residues, etc. are used.

[0027] The SGC 12 cools the high-temperature synthesis gas generated in the gasification furnace main body 11. The SGC 12 uses feed water or steam as a cooling medium and includes a heat transfer pipe (steam flow path) 12a through which feed water or steam flows. The steam cooled by the SGC 12 is led to the gasification furnace main body 11 through a steam input pipe (gasifying agent input section) 17.

[0028] An oxygen input pipe (gasifying agent input section) 18 is connected to the gasification furnace main body 11. Oxygen is supplied, for example, from an air separation facility (not shown) that separates and purifies oxygen from air in the atmosphere. The steam and oxygen fed into the gasification furnace main body 11 from each of the steam input pipe 17 and the oxygen input pipe 18 are used as gasifying agents for gasifying the biomass raw materials. That is, in the gasification furnace main body 11, the particulate biomass raw materials supplied therein are partially burned by oxygen and, through an aqueous shift reaction with steam, generate a synthesis gas containing hydrogen and carbon monoxide.

[0029] The dust collection device 13 is composed of one or more cyclones and porous filters, and separates the ash contained in the product gas generated in the gasification furnace main body 11. The product gas from which the ash has been separated is sent to the gas purification facility 14. The ash separated from the product gas is sent to, for example, a hopper (not shown) and temporarily stored, and then discharged to the outside at a predetermined timing.

[0030] The gas purification facility 14 uses a scrubber or the like to purify the gas by removing impurities such as nitrogen compounds and heavy metals from the product gas from which the ash has been separated. The purified product gas is supplied to the tar removal facility 15.

[0031] The tar removal facility 15 removes the tar contained in the product gas led from the gas purification facility 14. The tar removal facility 15 is, for example, a regenerative adsorption tower using activated carbon as an adsorbent, and the tar-containing water vapor discharged during regeneration is led from the tar-containing water vapor discharge section 15a to the gasification furnace main body 11 through the tar-containing water vapor supply pipe 20. The specific configuration of the tar removal facility 15 will be described later.

[0032] In the FT synthesis facility 5, a liquid synthetic fuel containing SAF is produced using the product gas as a raw material by the Fischer-Tropsch method. Also, by appropriately selecting the synthesis facility combined with the gasification furnace, it is also possible to produce liquid fuels such as methanol and ammonia from the product gas.

[0033] <Gasification furnace main body 11> Figure 2 shows the gasification furnace main body 11. The gasification furnace main body 11 is a dry furnace that separates the ash generated from the biomass raw material from the product gas with a dust collection device 13 arranged on the downstream side of the gasification furnace main body 11 in a solid state without melting the ash in the gasification furnace main body 11.

[0034] As shown in FIG. 2, the gasification furnace main body 11 has a cylindrical shape with a central axis CL extending in the vertical direction. The gasification furnace main body 11 includes a main body portion 11a, a first tapered portion 11b connected to the lower end of the main body portion 11a and gradually decreasing in diameter downward, a first cylindrical portion 11c connected to the lower end of the first tapered portion 11b and having a constant diameter, a second tapered portion 11d connected to the lower end of the first cylindrical portion 11c and gradually decreasing in diameter downward, and a second cylindrical portion 11e connected to the lower end of the second tapered portion 11d and having a constant diameter. Therefore, the flow path area of the gas flowing in the gasification furnace main body 11 increases in the order of the second cylindrical portion 11e, the first cylindrical portion 11c, and the main body portion 11a.

[0035] The raw material input section 22 for inputting biomass raw materials includes, for example, a screw feeder, and a predetermined amount of biomass raw materials is supplied into the gasification furnace main body 11. The raw material input section 22 is connected to the first cylindrical portion 11c. Note that as the raw material supply method, other input methods such as pneumatic conveying may be used instead of the screw feeder.

[0036] A steam input pipe 17 and an oxygen input pipe 18 are provided in a lower region below the raw material input section 22. Specifically, the steam input pipe 17 and the oxygen input pipe 18 are provided in the second cylindrical portion 11e. The steam input pipe 17 and the oxygen input pipe 18 are provided at the same height position as shown in FIG. 2.

[0037] A tar-containing steam supply pipe 20 is connected to the second cylindrical portion 11e. Thereby, the tar-containing steam discharged from the tar removal facility 15 is guided to the gasification furnace main body 11.

[0038] As described above, the lower second cylindrical portion 11e is a blowing portion where a gasifying agent in the form of steam and oxygen and tar-containing steam are input and blown up, the middle first cylindrical portion 11c is a combustion portion where biomass raw materials are input and partial combustion is performed, and the upper main body portion 11a is a gasification portion where a gasification reaction is performed.

[0039] The gas blowing-up speed (empty tower speed) of the second cylinder part 11e that is blown upward is controlled by a control part (not shown in the figure) to a speed at which the biomass raw material introduced from the first cylinder part 11c does not descend due to gravity.

[0040] The control part is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and a computer-readable storage medium, etc. And a series of processes for realizing various functions are stored in a storage medium, etc. in the form of a program as an example. The CPU reads out this program to the RAM, etc., and executes information processing and arithmetic processing, whereby various functions are realized. Note that the program may be in a form pre-installed in the ROM or other storage media, in a form provided in a state stored in a computer-readable storage medium, in a form distributed via wired or wireless communication means, etc. A computer-readable storage medium is a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, etc.

[0041] <Tar removal facility 15> In FIG. 3, a tar removal facility 15 is shown. The tar removal facility 15 is a regenerative adsorption tower and includes a first adsorption tower 31 and a second adsorption tower 32 provided in parallel with each other. Inside the first adsorption tower 31 and the second adsorption tower 32, activated carbon (adsorbent) for removing tar contained in the generated gas is accommodated. Note that the number of adsorption towers is two in this embodiment, but may be three or more.

[0042] The first adsorption tower 31 is provided with a first product gas introduction pipe 31a for introducing the product gas led from the gas purification facility 14, and a first product gas discharge pipe 31b for discharging the product gas after tar has been removed by activated carbon. On the first product gas introduction pipe 31a and the first product gas discharge pipe 31b, on-off valves 31a1 and 31b1 controlled by a control unit are provided respectively. Further, the first adsorption tower 31 is provided with a first steam introduction pipe 31c for introducing steam led from a steam source (not shown), and a first tar-containing steam discharge pipe 31d for discharging the steam together with the tar desorbed from the activated carbon by the steam as tar-containing steam. The upstream end of the first tar-containing steam discharge pipe 31d is connected to the tar-containing steam discharge section 15a. On the first steam introduction pipe 31c and the first tar-containing steam discharge pipe 31d, on-off valves 31c1 and 31d1 controlled by a control unit are provided respectively.

[0043] The second adsorption tower 32 is provided with a second product gas introduction pipe 32a for introducing the product gas led from the gas purification facility 14, and a second product gas discharge pipe 32b for discharging the product gas after tar has been removed by activated carbon. On the second product gas introduction pipe 32a and the second product gas discharge pipe 32b, on-off valves 32a1 and 32b1 controlled by a control unit are provided respectively. Further, the second adsorption tower 32 is provided with a second steam introduction pipe 32c for introducing steam led from a steam source (not shown), and a second tar-containing steam discharge pipe 32d for discharging the steam together with the tar desorbed from the activated carbon by the steam as tar-containing steam. The upstream end of the second tar-containing steam discharge pipe 32d is connected to the tar-containing steam discharge section 15a. On the second steam introduction pipe 32c and the second tar-containing steam discharge pipe 32d, on-off valves 32c1 and 32d1 controlled by a control unit are provided respectively.

[0044] The first tar-containing steam discharge pipe 31d and the second tar-containing steam discharge pipe 32d merge on the downstream side into the tar-containing steam supply pipe 20 and are led to the gasification furnace main body 11.

[0045] <Operation of the tar removal facility 15> The tar removal facility 15 configured as described above operates as follows. (1) Adsorption step (the first adsorption tower 31 in Fig. 3) Of the adsorption towers 31 and 32 filled with activated carbon, the generated gas is passed through one of the first adsorption towers 31 to remove tar. Specifically, the on-off valves 31a1, 31b1 of the first adsorption tower 31 are opened, and the on-off valves 31c1, 31d1 are closed. As a result, the generated gas led from the gas purification facility 14 is led into the first adsorption tower 31 through the first generated gas introduction pipe 31a, and the generated gas from which tar has been removed is supplied to the FT synthesis facility 5 through the first generated gas discharge pipe 31b.

[0046] In Fig. 3, the on-off valves 31a1, 31b1, 31c1, 31d1 are shown with white indicating open and black indicating closed (the same applies to the following figures).

[0047] (2) Regeneration step (the second adsorption tower 32 in Fig. 3) Steam is fed into the other second adsorption tower 32 where the supply of the generated gas has been stopped to desorb tar from the activated carbon based on the principle of TSA (Thermal Swing Adsorption). Specifically, the on-off valves 32c1, 32d1 of the second adsorption tower 32 are opened, and the on-off valves 32a1, 32b1 are closed. As a result, the regeneration steam is led into the second adsorption tower 32 through the second steam introduction pipe 32c to desorb tar from the activated carbon and regenerate the activated carbon. The steam after regeneration is discharged as tar-containing steam together with the desorbed tar from the tar-containing steam discharge section 15a through the second tar-containing steam discharge pipe 32d. The discharged tar-containing steam is supplied to the gasification furnace main body 11 through the tar-containing steam supply pipe 20.

[0048] (3) Rest period The adsorption tower that has completed the regeneration step waits for the next adsorption step. Alternatively, if there are other adsorption towers, those adsorption towers also wait for the next adsorption step. When the adsorption tower through which the generated gas is flowing shifts to the regeneration step, the waiting adsorption tower shifts to the adsorption step.

[0049] <Control of the amount of steam supplied to the gasification furnace body 11> Next, the control of the amount of steam supplied to the gasification furnace body 11 will be described. As shown in Fig. 3, a flow meter 20a is provided in the tar-containing steam supply pipe 20. The flow rate of the tar-containing steam is measured by the flow meter 20a, and its output is transmitted to the control unit. The control unit controls the amount of steam input supplied from the steam input pipe 17 to the gasification furnace body 11 by the steam control valve 17a according to the amount of steam contained in the tar-containing steam.

[0050] The control unit calculates the amount of steam in the tar-containing steam from the measurement value of the flow meter 20a based on the duration (hereinafter referred to as "opening time") from the start of the opening operation of the on-off valve 31c1 of the first steam introduction pipe 31c or the on-off valve 32c1 of the second steam introduction pipe 32c. Specifically, as a function Fx stored in the storage unit of the control unit, the relationship between the opening time of the on-off valves 31c1 and 32c1 and the tar concentration is obtained. This relationship can be obtained, for example, in advance through tests or the like. As the trend of the function Fx, the tar concentration is large at the initial stage of the opening time, and the tar concentration decreases as the opening time elapses. This is because more tar is desorbed at the initial stage of the discharge of the tar-containing steam and the tar concentration is high.

[0051] The current value of the tar flow rate is obtained by multiplying the output (tar concentration) of the function Fx obtained using the opening time of the on-off valves 31c1 and 32c1 by the flow rate of the tar-containing steam obtained by the flow meter 20a in the multiplication unit 34a. The current value of the steam flow rate is obtained by subtracting this tar flow rate from the flow rate of the tar-containing steam in the comparison operation unit 34b. The difference between this steam flow rate and the steam flow rate command value is obtained in the comparison operation unit 34c and used as the opening degree instruction value of the steam control valve 17a. The steam flow rate command value is the desired flow rate given as the appropriate operating condition of the gasification furnace body 11. Thereby, the total flow rate supplied to the gasification furnace body 11 is controlled to match the steam flow rate command value.

[0052] <Control of the amount of oxygen supplied to the gasification furnace body 11> Using the tar flow rate obtained by the flow meter 20a as described above, the amount of oxygen supplied from the oxygen supply pipe 18 (see FIG. 2) to the gasification furnace main body 11 is controlled. Specifically, based on the amount of tar supplied to the gasification furnace main body 11 and the input amount of the biomass raw material, the amount of oxygen supplied to the gasification furnace main body 11 is controlled. This control adjusts the supply amount of oxygen so that the oxygen ratio during the regeneration process is the same as the oxygen ratio before the regeneration process. Here, the oxygen ratio is the ratio of the supply amount of oxygen to the theoretical amount of oxygen required to completely burn the biomass raw material and the amount of tar supplied to the gasification furnace main body 11.

[0053] The effects of the present embodiment described above are as follows.

[0054] Since the tar-containing steam supply pipe 20 is connected to the second cylindrical portion 11e which is the lower region of the gasification furnace main body 11, the tar-containing steam generated when the activated carbon is regenerated is burned in the gasification furnace main body 11. Thereby, the calorific value of the tar desorbed from the activated carbon and the sensible heat of the steam can be effectively reused in the gasification furnace main body 11.

[0055] By introducing the tar-containing steam into the gasification furnace main body 11 through the tar-containing steam supply pipe 20 from the same second cylindrical portion 11e as the steam supply pipe 17 and the oxygen supply pipe 18 located in the second cylindrical portion 11e which is the lower region, it becomes possible to operate without reducing the total amount of the gas flow rate supplied to the second cylindrical portion 11e. Thereby, the superficial gas velocity in the second cylindrical portion 11e is maintained at a desired value, the fall of the biomass raw material is prevented, and by preventing an increase in the oxygen concentration in the second cylindrical portion 11e, abnormal temperature rise in the second cylindrical portion 11e during the regeneration process of the tar removal facility 15 and in the first cylindrical portion 11c located above the second cylindrical portion 11e can be avoided, and good combustion or pyrolysis in the gasification furnace main body 11 can be realized.

[0056] By introducing tar-containing steam from the tar-containing steam supply pipe 20 into the gasification furnace body 11, the combustion and pyrolysis states in the gasification furnace body 11 may change in relation to the steam introduced into the gasification furnace body 11. Therefore, the control unit controls the amount of steam introduced from the steam input pipe 17 according to the supply amount of the tar-containing steam supplied to the gasification furnace body 11. Thereby, good combustion or pyrolysis of the gasification furnace body 11 can be realized.

[0057] Based on the tar flow rate supplied to the gasification furnace body 11 and the biomass raw material, the supply amount of oxygen is adjusted so that the oxygen ratio during the regeneration process is the same as the oxygen ratio before the regeneration process. Thereby, good combustion or pyrolysis of the gasification furnace body 11 can be realized.

[0058] [Modification Example 1] The above embodiment can be modified as shown in FIG. 4. FIG. 4 corresponds to FIG. 3, and the control method of the steam control valve 17a is different.

[0059] As shown in FIG. 4, in addition to the flow meter 20a, a tar concentration measuring device 20b is provided in the tar-containing steam supply pipe 20. The tar concentration measuring device 20b is, for example, a laser type, and measures the tar concentration in the tar-containing steam. The output of the tar concentration measuring device 20b is transmitted to the control unit.

[0060] The tar concentration measured by the tar concentration measuring device 20b is multiplied by the output of the flow meter 20a in the multiplication unit 35a of the control unit, whereby the current value of the tar flow rate in the tar-containing steam is obtained. By subtracting this tar flow rate from the flow rate of the tar-containing steam in the comparison operation unit 35b, the current value of the steam flow rate is obtained. The difference between this steam flow rate and the steam flow rate command value is obtained by the comparison operation unit 35c and used as the opening degree command value of the steam control valve 17a. Thereby, the total flow rate supplied to the gasification furnace body 11 is controlled to match the steam flow rate command value.

[0061] Further, based on the tar flow rate calculated using the tar concentration obtained by the tar concentration measuring device 20b and the biomass raw material supplied to the gasification furnace main body 11, similar to the embodiment described with reference to FIG. 3, the supply amount of oxygen is adjusted so that the oxygen ratio during the regeneration process is the same as the oxygen ratio before the regeneration process.

[0062] [Modification Example 2] The above embodiment can be modified as shown in FIG. 5. FIG. 5 corresponds to FIG. 3, and the control method of the steam control valve 17a is different.

[0063] As shown in FIG. 5, in addition to the flow meter 20a, a density meter 20c is provided in the tar-containing steam supply pipe 20. The density meter 20c measures the density of the tar-containing steam. The output of the density meter 20c is transmitted to the control unit.

[0064] The density of the tar-containing steam measured by the density meter 20c is subtracted from the tar density by the comparison calculator 36a of the control unit. The tar density used in this modification example is stored in the storage unit of the control unit and is given as a function of, for example, temperature and pressure. Therefore, the tar density used by the comparison calculator 36a is corrected by the temperature and pressure of the tar-containing steam measured by the density meter 20c (the temperature and pressure measured by a temperature sensor and a pressure sensor not shown). In the comparison calculator 36b, the steam density is subtracted from the tar density corrected by the temperature and pressure of the tar-containing steam. The steam density is also a function of temperature and pressure similar to the tar density. By dividing the output of the comparison calculator 36a by the output of the comparison calculator 36b by the divider 36c, the current value of the steam concentration in the tar-containing steam is obtained. By multiplying this steam concentration by the flow rate of the tar-containing steam by the multiplier 36d, the current value of the steam flow rate in the tar-containing steam is obtained. The difference between this steam flow rate and the steam flow rate command value is obtained by the comparison calculation unit 36e and used as the opening degree instruction value of the steam control valve 17a. Thereby, the total flow rate supplied to the gasification furnace main body 11 is controlled to match the steam flow rate command value.

[0065] Also, based on the tar flow rate calculated using the tar density obtained by the densitometer 20c and the biomass raw material supplied to the gasification furnace main body 11, the oxygen supply amount is adjusted so that the oxygen ratio during the regeneration process is the same as the oxygen ratio before the regeneration process, in the same manner as the embodiment described with reference to FIG. 3.

[0066] [Modification Example 3] The above embodiment can be modified as shown in FIG. 6. FIG. 6 corresponds to FIG. 1, and the supply destination of the tar-containing steam discharged from the tar removal facility 15 is different.

[0067] As shown in FIG. 6, a header portion 12e is provided at an intermediate position of the heat transfer tube 12a between the SGCs 12. The tar-containing steam supply pipe 20 connected to the tar-containing steam discharge portion 15a merges with the steam flowing through the heat transfer tube 12a of the SGC 12 at a merging portion 12b provided in the header portion 12e. After the tar-containing steam merges with the steam flowing through the heat transfer tube 12a at the merging portion 12b, it is guided to the gasification furnace main body 11 through the steam input pipe 17.

[0068] An auxiliary steam branch pipe 12d branches from a branch portion (extraction portion) 12c provided in the header portion 12e. The steam extracted from the auxiliary steam branch pipe 12d can be used, for example, for drying the biomass raw material, as a heating medium for a heat exchanger installed in the facility, or as a heating source for heat insulation of equipment and piping.

[0069] The branch portion 12c from which the auxiliary steam branch pipe 12d branches is provided on the upstream side of the steam flow flowing through the header portion 12e, rather than the merging portion 12b of the tar-containing steam supply pipe 20. Thereby, since there is no possibility that the tar-containing steam is contained in the extracted steam, it is possible to prevent the extracted steam from being led to other equipment and contaminated with tar.

[0070] In the above-described embodiments, as a specific example of the tar removal facility 15, as shown in FIGS. 3 to 5, the adsorption and desorption of tar are alternately performed in each of the adsorption towers 31 and 32 installed in parallel. However, the present invention is not limited to this. For example, a method of simultaneously performing adsorption and desorption in one cylinder may be adopted. Specifically, it includes a fluidized bed adsorption section in which activated carbon (adsorbent) forms a fluidized bed to adsorb tar, a moving bed desorption section in which the activated carbon adsorbed with tar is guided downward and moves while desorbing tar, and an air flow conveyance section that conveys the activated carbon that has completed desorption to the upper fluidized bed adsorption section by air flow. Thereby, the adsorption and desorption of tar are continuously performed in one cylinder. In this case, the tar-containing water vapor is discharged from the moving bed desorption section.

[0071] The biomass gasification furnace, the liquid fuel production facility, and the operation method of the biomass gasification furnace described in each of the above-described embodiments can be understood as follows, for example.

[0072] The biomass gasification furnace (3) according to the first aspect of the present disclosure includes a gasification furnace main body (11) that gasifies a biomass raw material, a biomass raw material input section (22) that inputs the biomass raw material into the interior of the gasification furnace main body (11), a gasification agent input section (17, 18) provided in a lower region below the biomass raw material input section (22) that inputs a gasification agent into the interior of the gasification furnace main body (11), and a tar removal facility (15) that adsorbs and removes tar from the product gas generated in the gasification furnace main body (11) with an adsorbent. The tar removal facility (15) includes a tar-containing water vapor discharge section (15a) that discharges the tar-containing water vapor generated when the tar adsorbed on the adsorbent is desorbed by water vapor to regenerate the adsorbent, and a tar-containing water vapor supply pipe (20) that supplies the tar-containing water vapor led from the tar-containing water vapor discharge section (15a) to the lower region is provided.

[0073] Since the tar-containing steam supply pipe is connected to the lower region of the gasification furnace body, the tar-containing steam generated when the adsorbent is regenerated is burned in the gasification furnace body. As a result, the calorific value of the tar desorbed from the adsorbent and the sensible heat of the steam can be effectively reused in the gasification furnace body. Also, by introducing the tar-containing steam into the gasification furnace body from the same lower region as the gasifying agent inlet located in the lower region, it becomes possible to operate without reducing the total amount of the gas flow rate supplied to the lower region. As a result, the superficial velocity in the lower region is maintained at a desired value, preventing the biomass raw material from falling, and preventing an increase in the oxygen concentration in the lower region, thereby avoiding abnormal temperature rises in the lower region during the regeneration process of the tar removal facility and in the biomass raw material inlet located above the lower region, and enabling good combustion or pyrolysis in the gasification furnace body.

[0074] The biomass gasification furnace (3) according to the second aspect of the present disclosure includes a gasification furnace body (11) for gasifying a biomass raw material, a biomass raw material inlet (22) for introducing the biomass raw material into the interior of the gasification furnace body (11), a gasifying agent inlet (17, 18) provided in a lower region below the biomass raw material inlet (22) for introducing a gasifying agent into the interior of the gasification furnace body (11), a product gas cooler (12) for cooling the product gas generated in the gasification furnace body (11), and a tar removal facility (15) for adsorbing and removing tar from the product gas led from the product gas cooler (12) with an adsorbent. The tar removal facility (15) includes a tar-containing steam discharge section (15a) for discharging the tar-containing steam generated when the tar adsorbed on the adsorbent is desorbed by steam to regenerate the adsorbent, and a tar-containing steam supply pipe (20) for guiding the tar-containing steam led from the tar-containing steam discharge section (15a). The tar-containing steam supply pipe (20) is connected to the gasification furnace body (11) via the cooling medium flow path (12a) of the product gas cooler (12).

[0075] Since the tar-containing steam is passed through the cooling medium flow path of the product gas cooler, the temperature of the tar-containing steam can be raised. Since the tar-containing steam is led to the gasifier main body after the temperature is raised, good combustion or pyrolysis can be realized without lowering the temperature inside the gasifier main body. In addition, since the tar-containing steam discharge part is connected to the gasifier main body via the tar-containing steam supply pipe and the cooling medium flow path of the product gas cooler, the tar-containing steam generated when the adsorbent is regenerated is burned in the gasifier main body. Thereby, the calorific value of the tar desorbed from the adsorbent can be effectively reused in the gasifier main body. Note that the tar-containing steam may be supplied to the lower region of the gasifier main body as in the first embodiment.

[0076] The biomass gasifier (3) according to the third aspect of the present disclosure includes a gasifier main body (11) for gasifying a biomass raw material, a biomass raw material input part (22) for inputting the biomass raw material into the gasifier main body (11), a gasifying agent input part (17, 18) provided in a lower region below the biomass raw material input part (22) for inputting a gasifying agent into the gasifier main body, and a tar removal facility (15) for adsorbing and removing tar from the product gas generated in the gasifier main body (11) with an adsorbent. The tar removal facility (15) includes a tar-containing steam discharge part (15a) for discharging the tar-containing steam generated when the tar adsorbed on the adsorbent is desorbed by steam and the adsorbent is regenerated, and a tar-containing steam supply pipe (20) for guiding the tar-containing steam led from the tar-containing steam discharge part (15a). It is provided with a control part for controlling the input amount of steam input to the gasifier main body (11) according to the supply amount of the tar-containing steam supplied from the tar-containing steam supply pipe (20) to the gasifier main body (11).

[0077] Since the tar-containing steam discharge section is connected to the gasification furnace body via the tar-containing steam supply pipe, the tar-containing steam generated when the adsorbent is regenerated is combusted in the gasification furnace body. As a result, the calorific value of the tar desorbed from the adsorbent can be effectively reused in the gasification furnace body. On the other hand, by introducing the tar-containing steam into the gasification furnace body, the state of combustion and pyrolysis in the gasification furnace body may change in relation to the steam introduced into the gasification furnace body. Therefore, the control unit controls the amount of steam introduced from the gasification agent input section according to the amount of tar-containing steam supplied from the tar-containing steam supply pipe to the gasification furnace body. Thereby, good combustion or pyrolysis of the gasification furnace body can be realized. Note that this aspect can be combined with the first aspect or the second aspect.

[0078] The biomass gasification furnace (3) according to the fourth aspect of the present disclosure is any one of the first aspect to the third aspect, and in the cooling medium flow paths (12a, 12e) of the product gas cooler (12), an extraction section (12c) for extracting a part of the steam as the cooling medium is provided, and the tar-containing steam discharge section (15a) is connected so that the tar-containing steam is guided to the downstream side of the extraction section (12c) in the cooling medium flow.

[0079] Steam extracted from the extraction section of the cooling medium flow path of the product gas cooler is used as auxiliary steam used in the biomass gasification furnace. The tar-containing steam discharge section is connected so that the tar-containing steam is guided to the downstream side of the extraction section in the cooling medium flow. As a result, there is no possibility that the tar-containing steam is contained in the extracted steam, so that it is possible to prevent contamination with tar when the extracted steam is guided to other equipment.

[0080] The biomass gasification furnace (3) according to the fifth aspect of the present disclosure is the same as that in the third aspect or the fourth aspect, wherein sensors (20a, 20b, 20c) for detecting the physical quantity of the tar-containing steam flowing through the tar-containing steam supply pipe (20) are provided, and the control unit calculates the amount of steam contained in the tar-containing steam flowing through the tar-containing steam supply pipe (20) using the sensors (20a, 20b, 20c), and controls the input amount of steam input into the gasification furnace main body (11) according to the amount of steam.

[0081] The amount of steam contained in the tar-containing steam is calculated by a sensor provided in the tar-containing steam supply pipe. Since the input amount of steam input into the gasification furnace main body (11) is controlled based on this amount of steam, it is possible to control the amount of steam supplied to the gasification furnace main body by eliminating the influence of the tar contained in the tar-containing steam. Examples of the sensor for detecting the physical quantity of the tar-containing steam include a flow meter, a tar concentration measuring instrument, a density meter, and the like.

[0082] The biomass gasification furnace (3) according to the sixth aspect of the present disclosure is the same as that in any one of the third aspect to the fifth aspect, wherein the control unit controls the amount of oxygen supplied to the gasification furnace main body (11) according to the tar flow rate contained in the tar-containing steam supplied from the tar-containing steam supply pipe (20) to the gasification furnace main body (11).

[0083] The supply amount of oxygen is adjusted according to the tar flow rate supplied to the gasification furnace main body. Thereby, good combustion or pyrolysis of the gasification furnace main body can be realized.

[0084] The liquid fuel production facility (1) according to the first aspect of the present disclosure includes the biomass gasification furnace (3) described in any one of the first aspect to the sixth aspect, and a liquid fuel synthesis facility (5) for synthesizing liquid fuel from at least a part of the produced gas generated in the gasification furnace main body (11).

[0085] The operation method of the biomass gasification furnace (3) according to the first aspect of the present disclosure includes a gasification furnace main body (11) for gasifying biomass raw materials, a biomass raw material input section (22) for inputting biomass raw materials into the interior of the gasification furnace main body (11), a gasifying agent input section (17, 18) provided in a lower region below the biomass raw material input section (22) for inputting a gasifying agent into the interior of the gasification furnace main body (11), and a tar removal facility (15) for adsorbing and removing tar from the produced gas generated in the gasification furnace main body (11) with an adsorbent. The operation method of the biomass gasification furnace (3) is such that the tar removal facility (15) includes a tar-containing water vapor discharge section (15a) for discharging the tar-containing water vapor generated when the tar adsorbed on the adsorbent is desorbed by water vapor to regenerate the adsorbent, and the tar-containing water vapor led from the tar-containing water vapor discharge section (15a) is supplied to the lower region.

Explanation of Reference Numerals

[0086] 1 Liquid fuel production facility 3 Biomass gasification furnace 5 FT synthesis facility (liquid fuel synthesis facility) 11 Gasification furnace main body 11a Main body section 11b First tapered section 11c First cylindrical section 11d Second tapered section 11e Second cylindrical section (lower region) 12 SGC (produced gas cooler) 12a Heat transfer tube (water vapor flow path) 12b Confluence section 12c Branch section (extraction section) 12d Auxiliary steam branch pipe 12e Header section 13 Dust collector 14 Gas purification facility 15 Tar removal facility 15a Tar-containing water vapor discharge section 17 Steam input pipe (gasifying agent input section) 17a Steam control valve 18 Oxygen input pipe (gasifying agent input section) 20 Tar-containing steam supply pipe 20a Flow meter 20b Tar concentration measuring device 20c Density meter 22 Raw material input section (biomass raw material input section) 31 First adsorption tower 31a First product gas inlet pipe 31a1 On-off valve 31b First product gas discharge pipe 31b1 On-off valve 31c First steam inlet pipe 31c1 On-off valve 31d First tar-containing steam discharge pipe 32 Second adsorption tower 32a Second product gas inlet pipe 32a1 On-off valve 32b Second product gas discharge pipe 32b1 On-off valve 32c Second steam inlet pipe 32c1 On-off valve 32d Second tar-containing steam discharge pipe 34a Multiplication unit 34b Comparison operation unit 34c Comparison operation unit 35a Multiplication unit 35b Comparison operation unit 35c Comparison operation unit CL Central axis

Claims

1. A gasification furnace body for gasifying biomass raw materials, a biomass raw material input section for inputting the biomass raw materials into the interior of the gasification furnace body, a gasifying agent input section provided in a lower region below the biomass raw material input section for inputting a gasifying agent into the interior of the gasification furnace body, tar removal equipment for adsorbing and removing tar from the produced gas generated in the gasification furnace body with an adsorbent, comprising: the tar removal equipment includes a tar-containing water vapor discharge section for discharging the tar-containing water vapor generated when the tar adsorbed on the adsorbent is desorbed by steam to regenerate the adsorbent, a biomass gasification furnace provided with a tar-containing water vapor supply pipe for supplying the tar-containing water vapor led from the tar-containing water vapor discharge section to the lower region.

2. A gasification furnace body for gasifying biomass raw materials, a biomass raw material input section for inputting the biomass raw materials into the interior of the gasification furnace body, a gasifying agent input section provided in a lower region below the biomass raw material input section for inputting a gasifying agent into the interior of the gasification furnace body, a produced gas cooler for cooling the produced gas generated in the gasification furnace body, tar removal equipment for adsorbing and removing tar from the produced gas led from the produced gas cooler with an adsorbent, comprising: the tar removal equipment includes a tar-containing water vapor discharge section for discharging the tar-containing water vapor generated when the tar adsorbed on the adsorbent is desorbed by steam to regenerate the adsorbent, comprising a tar-containing water vapor supply pipe for guiding the tar-containing water vapor led from the tar-containing water vapor discharge section, the tar-containing water vapor supply pipe is connected to the gasification furnace body through a cooling medium flow path of the produced gas cooler, a biomass gasification furnace.

3. A gasification furnace body for gasifying biomass raw materials, a biomass raw material input section for inputting the biomass raw materials into the interior of the gasification furnace body, a gasifying agent input section provided in a lower region below the biomass raw material input section for inputting a gasifying agent into the interior of the gasification furnace body, tar removal equipment for adsorbing and removing tar from the produced gas generated in the gasification furnace body with an adsorbent, comprising: the tar removal equipment includes a tar-containing water vapor discharge section for discharging the tar-containing water vapor generated when the tar adsorbed on the adsorbent is desorbed by steam to regenerate the adsorbent, comprising a tar-containing water vapor supply pipe for guiding the tar-containing water vapor led from the tar-containing water vapor discharge section, A biomass gasification furnace comprising a control unit that controls the amount of steam input into the gasification furnace main body according to the amount of tar-containing steam supplied from the tar-containing steam supply pipe to the gasification furnace main body.

4. An extraction section for extracting a part of the steam as a cooling medium is provided in the cooling medium flow path of the product gas cooler. The biomass gasification furnace according to claim 2, wherein the tar-containing steam discharge section is connected such that tar-containing steam is led to the downstream side of the extraction section in the cooling medium flow.

5. A sensor for detecting the physical quantity of the tar-containing steam flowing through the tar-containing steam supply pipe is provided. The biomass gasification furnace according to claim 3, wherein the control unit calculates the amount of steam contained in the tar-containing steam flowing through the tar-containing steam supply pipe using the detection value of the sensor, and controls the amount of steam input into the gasification furnace main body according to the amount of steam.

6. The biomass gasification furnace according to claim 3, wherein the control unit controls the amount of oxygen supplied to the gasification furnace main body according to the tar flow rate contained in the tar-containing steam supplied from the tar-containing steam supply pipe to the gasification furnace main body.

7. The biomass gasification furnace according to any one of claims 1 to 6, Liquid fuel synthesis equipment for synthesizing liquid fuel from at least a part of the product gas generated in the gasification furnace main body, A liquid fuel production facility comprising.

8. A gasification furnace main body for gasifying biomass raw materials, A biomass raw material input section for inputting biomass raw materials into the interior of the gasification furnace main body, A gasification agent input section provided in a lower region below the biomass raw material input section for inputting a gasification agent into the interior of the gasification furnace main body, Tar removal equipment for adsorbing and removing tar from the product gas generated in the gasification furnace main body with an adsorbent, A method for operating a biomass gasification furnace comprising: The tar removal equipment includes a tar-containing steam discharge section for discharging tar-containing steam generated when the tar adsorbed on the adsorbent is desorbed by steam to regenerate the adsorbent, A method for operating a biomass gasification furnace in which the tar-containing steam led from the tar-containing steam discharge section is supplied to the lower region.

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