JP4561481B2 - Gas purification equipment - Google Patents

Description

The present invention relates to a gas purification apparatus for purifying a gas obtained by thermochemical gasification of biomass, fossil fuel or waste.
Biomass refers to organic resources derived from living organisms, such as forest resources, marine biological resources (fishery products, seaweed), agricultural products, livestock products themselves, or organic waste (wood waste, thinned wood, rice husks) after using them. , Palm empty fruit bunch, palm oil residue, construction generated wood, etc.).
In addition, in the present specification, the term “biomass” includes not only the above-mentioned biomass but also biomass and solid fuel such as general waste, industrial waste, sludge, coal, RDF / RPF, and liquid fuel such as kerosene / heavy oil. It shall also contain a mixture. Further, the present invention is also applied to a mixed gas of a gas obtained by thermochemically gasifying biomass and a gas fuel such as natural gas.
Examples of fossil fuels include coal, petroleum, oil shale, and oil sand. Examples of waste include general waste, industrial waste, and sludge.

In recent years, development of biomass conversion technology that converts biomass resources into energy, industrial raw materials, and the like has been progressing.
In particular, development related to thermochemical gasification of biomass is advancing, and research and development related to power generation using gas, gas turbines, boilers and steam turbines, and power generation introduced into fuel cells using biomass gas as gas fuel. Has been done.
In the present invention, a gas obtained by thermochemical gasification of biomass, that is, gasification by biomass pyrolysis reaction, partial oxidation reaction or the like is referred to as biomass gas.
When biomass gas is used, the first problem is that biomass gas contains a large amount of tar, so if this is not removed, tar will adhere to the gas utilization device, causing the device to deteriorate or become clogged. It is to cause. Therefore, removal of tar from biomass gas is an important technology that is a prerequisite for using biomass gas.
However, few technologies have been proposed in Japan for removing tar from biomass gas, and there are few examples overseas.

  According to the inventor's investigation, as an example in a foreign country, there is one in which wood biomass is gasified and supplied to a gas engine to generate electricity, and tar in the gas is cleaned. In the example shown here, biomass gas generated in a gasifier is introduced into a two-stage cyclone to remove dust having a large particle size, and then washed with a wet scrubber to further remove dust and tar. This is a wet removal device that lowers the temperature and further removes tar with a wet electric dust collector (see Non-Patent Document 1).

In addition to tar, biomass gas often contains sulfur compounds such as H ₂ S and COS (carbonyl sulfide), and the following problems arise if this is not removed.
When the biomass gas is burned as it is, the sulfur compound is discharged as sulfur oxides from the chimney to the atmosphere and becomes an environmental destruction source such as acid rain, and the problem of corrosion of the apparatus occurs.
Also in fuel cell power generation, there are problems of a decrease in power generation efficiency at the electrodes and a decrease in device durability.
Further, when a liquid fuel such as dimethyl ether or methanol is synthesized from biomass gas, the synthesis catalyst is poisoned.

In this way, sulfur compounds contained in biomass gas become a source of various problems, so removing sulfur compounds from biomass gas is an important technology that is a prerequisite for using biomass gas as well as tar removal. is there.
However, as with the case of tar, there has been little proposal for a technique for removing sulfur compounds from biomass gas.
However, although it is not biomass gas, the following has been proposed as a technique for refining gasification gas obtained from coal or heavy oil.
As a method for removing the sulfur compound, H ₂ S (hydrogen sulfide) is removed with a wet scrubber using an aqueous solution of amines. Then, COS that cannot be removed with an aqueous solution of amines is converted into a form of H ₂ S that can be removed with an aqueous solution of amines by performing a hydrolysis reaction represented by the following formula using a COS conversion catalyst. (See Patent Document 1)
COS + H ₂ O → H ₂ S + CO ₂
Gas engine operation on fuel gas from CFBbiomass gasifer, LPLMRabou, Contributions ECN biomass to the “12thEuropean conference and Technology exhibition on biomass for energy, industry and climate protection”, Amsterdam, 2002, p12 Japanese Patent Laying-Open No. 2004-75712 (see paragraph “0004”)

  Those described in Non-Patent Document 1 and Patent Document 1 described above cannot efficiently remove both tar and sulfur compounds contained in biomass gas, but remove both tar and sulfur compounds contained in biomass gas. Thus, there is no gas refining apparatus that makes it possible to use biomass gas as energy, and there is a problem that the present technology cannot effectively use biomass gas.

Further, for example, as shown in Non-Patent Document 1, when the biomass gas generated in the gasification furnace is washed with a wet scrubber to remove dust and tar, the treatment of washing waste water containing tar is performed. As a result, the wastewater treatment load is large and the entire gas refining facility becomes large. As a result, there is a problem that the facility cost and the operation cost increase in terms of facility cost, installation area, facility maintenance, and the like.
Furthermore, although the above method seems to have a certain effect on the removal of tar, it also removes mixed gas components that become gas fuel among biomass gas components and mixed gas components useful for liquid fuel synthesis. There is also the problem of end up.

In addition, when biomass gas is washed with a wet scrubber to remove sulfur compounds, it is necessary to treat the waste water containing sulfur compounds, and the equipment and operating costs are in terms of equipment costs, installation area, equipment maintenance, etc. There is a problem that increases.
Further, such as that shown in Patent Document 1, the COS and converted to H _{2 S,} when so removed by washing H 2 _S, the conversion reactor is required, the problem of processing of the washing waste water In addition, there is a problem that the equipment cost related to the conversion reaction apparatus is increased.
Furthermore, the above-described method also has a problem that a mixed gas component that becomes a gas fuel among biomass gas components and a mixed gas component useful for liquid fuel synthesis are also removed.

In the so-called gasification-liquid fuel synthesis system, which is one of the biomass gas utilization methods, gas is once gasified and liquid fuel is synthesized. An apparatus that is easy to operate and maintain and that can effectively remove sulfur compounds is desired so that the gas can be directly used for gas fuel or liquid fuel synthesis. However, the conventional apparatus as described above cannot meet this demand. .
The problem in the removal of tar and sulfur compounds as described above is the same for the gas obtained by thermochemical gasification of fossil fuel or waste other than biomass gas.

The present invention has been made to solve such problems, and a first object is to efficiently remove tar and sulfur compounds in gas obtained by thermochemical gasification of biomass, fossil fuel or waste. The object is to obtain a gas purifier that can be used.
A second object is to obtain a gas purifier capable of removing tar and sulfur compounds in the gasification gas without reducing the useful mixed gas components generated by the gasification.

(1) A gas purification apparatus according to the present invention is an apparatus for purifying a gasification gas obtained by thermochemical gasification, and is filled with a tar remover that passes the gasification gas and removes the tar. A tar removal device having a tar removal agent layer, and a sulfur compound removal agent that is disposed on the downstream side of the tar removal device and passes through the gasification gas to remove H ₂ S and / or COS. A sulfur compound removing device having a sulfur compound removing agent layer,
The tar removal device includes a moving bed type tar removal device that renews the tar removal agent layer by moving the tar removal agent layer, and the tar removal agent layer disposed on the downstream side of the moving bed type tar removal device. There will be a fixed bed tar removal device comprising a fixed, said sulfur compound removal device, characterized in that consists of a fixed bed of sulfur compound removal apparatus for removing sulfur compounds agent layer are fixed is there.

  In the above gas purifier, the moving bed type tar removing device is arranged upstream for tar removal, and the fixed bed type tar removing device is arranged on the downstream side. The treatment of a large amount of washing water as in the case of installation is not required, and since it is a dry type, the equipment scale is reduced in size and the cost is reduced. In addition, since the moving bed type tar removal device is arranged on the upstream side, the activated carbon with reduced tar removal ability can be renewed, so even if a large amount of tar is removed on the upstream side, smooth operation is possible without causing clogging. it can.

(2) An apparatus for purifying a gasification gas obtained by thermochemical gasification,
A tar removal device having a tar removal agent layer filled with a tar removal agent that removes tar by passing the gasification gas; and a gas removal gas disposed downstream of the tar removal device to pass the gasification gas. A sulfur compound removing apparatus having a sulfur compound removing agent layer filled with a sulfur compound removing agent that removes H ₂ S and / or COS, and the atmospheric temperature of the tar removing agent layer is 130 to 500 ° C. Temperature adjusting means for adjusting the temperature of the gasification gas,
The tar remover is activated carbon, and the tar remover includes a moving bed type tar remover that moves the tar remover layer to renew the tar remover layer, and the sulfur compound remover is a sulfur compound. It consists of a fixed bed type sulfur compound removing device to which a remover layer is fixed.
Since the activated carbon is used as the remover and the ambient temperature of the remover layer is set to 130 to 500 ° C., only the tar contained in the biomass gas is removed by the activated carbon and effectively purified.
In addition, adjustment of the atmospheric temperature of a removal agent layer is performed by adjusting the temperature of the biomass gas introduce | transduced into a removal agent layer, or heating or cooling a removal agent layer from the outside or the inside.

(3) An apparatus for purifying a gasification gas obtained by thermochemical gasification,
A tar removal device having a tar removal agent layer filled with a tar removal agent that removes tar by passing the gasification gas; and a gas removal gas disposed downstream of the tar removal device to pass the gasification gas. and a sulfur compound removal device having a H 2 _S and / or sulfur compound removal agent layer formed by filling a sulfur compound removal agent to remove COS,
The tar removal device includes a fixed bed type tar removal device in which the tar removal agent layer is fixed, and the sulfur compound removal device includes a fixed layer type sulfur compound removal device in which a sulfur compound removal agent layer is fixed. It is characterized by.

(4) An apparatus for purifying a gasification gas obtained by thermochemical gasification,
A moving bed type tar removal that has a tar removal agent layer that is filled with a tar removal agent that passes through the gasification gas and removes the tar, and moves the tar removal agent layer to renew the tar removal agent layer. A tar removal agent layer disposed downstream of the tar removal device to remove tar that has not been removed by the tar removal device; and the gasification gas disposed downstream of the tar removal agent layer. And a tar / sulfur compound removal device having a sulfur compound removal agent layer that is filled with a sulfur compound removal agent that passes H ₂ S and / or COS.
In the tar / sulfur compound removing apparatus, the tar removing agent layer and the sulfur compound removing agent layer are fixed to each other.

(5) An apparatus for purifying a gasification gas obtained by thermochemical gasification,
Tar remover / sulfur compound remover formed by mixing and filling a tar remover for removing tar in the gasified gas and a sulfur compound remover for removing H ₂ S and / or COS in the gasified gas The tar removal agent / sulfur compound removal agent mixed layer has a mixing layer, and the tar removal agent / sulfur compound removal agent mixed layer is moved to update the tar removal agent / sulfur compound removal agent mixed layer. It is a layer type.

(6) An apparatus for purifying a gasification gas obtained by thermochemical gasification,
Tar remover / sulfur compound remover formed by mixing and filling a tar remover for removing tar in the gasified gas and a sulfur compound remover for removing H ₂ S and / or COS in the gasified gas It has a mixed layer, and the tar remover / sulfur compound remover mixed layer is a fixed layer type.

(7) An apparatus for purifying a gasification gas obtained by thermochemical gasification,
A moving bed type tar removal that has a tar removal agent layer that is filled with a tar removal agent that passes through the gasification gas and removes the tar and moves the tar removal agent layer to renew the tar removal agent layer. Tar remover / sulfur obtained by mixing and filling a device, a tar remover for removing tar in the gasified gas, and a sulfur compound remover for removing H ₂ S and / or COS in the gasified gas And a tar / sulfur compound removing device having a compound remover mixed layer, wherein the tar remover / sulfur compound remover mixed layer is a fixed-bed type.

(8) Moreover, the tar removing agent according to any one of the above (1) to (7) is activated carbon, and the activated carbon has a specific surface area of 250 m ² / g or more and / or an average pore diameter of 0.1 nm or more. It is characterized by being.

(9) Moreover, the sulfur compound removing agent according to any one of the above (1) to (8) is a carbonaceous material.
The carbonaceous material referred to in the present invention is a substance mainly containing carbon having a sulfur compound removing function, such as activated carbon, coke, activated coke, coal, charcoal, graphite (graphite), graphite, fullerene, carbon. There are black and carbon nanotubes.

(10) Moreover, the sulfur compound removing agent according to any one of the above (1) to (8) is activated carbon.

(11) Moreover, the sulfur compound removing agent according to any one of the above (1) to (8) is activated carbon, and the gasification gas is adjusted so that the atmospheric temperature of the sulfur compound removing agent layer is 160 to 500 ° C. A temperature adjusting means for adjusting the temperature is provided.

(12) Moreover, the sulfur compound removing agent according to any one of the above (1) to (8) is a biomass char, lignite char, or iron-supported lignite char .
Char is a carbon substance that remains after pyrolysis, gasification, dry distillation, and carbonization. Includes those using char as it is and those activated by activation treatment. In addition, when the activation treatment is performed, the sulfur removal performance is further improved.

(13) The sulfur compound remover according to any one of the above (1) to (8) is a biomass char, lignite char or iron-supported lignite char , and the sulfur compound remover layer has an atmospheric temperature of 160 to 500 ° C. it is characterized in further comprising a temperature adjusting means for adjusting the temperature of the gasification gas so.

In the inventions of the above (12) to (13) , the sulfur compound remover uses biomass char, lignite char or iron-supported lignite char , whereby the decomposition reaction of H ₂ S and / or COS is promoted, and H ₂ S and / or COS can be effectively removed.

  In the present invention, the tar removal device is arranged on the upstream side, and the sulfur compound removal device is arranged on the downstream side of the tar removal device, whereby tar and sulfur compounds contained in the biomass gas can be efficiently removed, The gas can be purified as a gas that can be effectively used as energy.

[Embodiment 1]
FIG. 1 is an explanatory view for explaining the entire gas purification apparatus according to an embodiment of the present invention. As shown in FIG. 1, the gas purification apparatus according to the present embodiment includes a temperature adjustment device 2 that adjusts the temperature of biomass gas generated by the gasification furnace 1 so as to fall within a predetermined temperature range, and biomass. A dust removing device 3 that removes dust contained in the gas, a moving bed type tar removing device 5 that is provided downstream of the dust removing device 3 to remove tar in biomass gas, and the moving bed type tar removing device 5 Further, a fixed bed type tar removing device 7 provided further on the downstream side to further remove tar in the biomass gas, and a sulfur compound provided on the downstream side of the fixed bed type tar removing device 7 to remove sulfur compounds in the biomass gas. And a removing device 9. The biomass gas from which tar has been removed by the moving bed type tar removing device 5 and the fixed bed type tar removing device 7 and from which the sulfur compound has been removed by the sulfur compound removing device 9 is adjusted to an appropriate temperature by the cooler 10 as necessary. To the gas utilization facility 11.
Hereinafter, each configuration will be described in more detail.

<Gasification furnace>
The gasification furnace is not limited in its form, and various types can be used. For example, a fixed bed, a fluidized bed, a circulating fluidized bed, a rotary furnace, a moving bed, a spouted bed, an indirect heating gasification furnace, and combinations thereof There are things. The biomass is heated while supplying steam, air, oxygen, etc., and gas such as hydrogen, CO, hydrocarbons, etc. is generated by a thermochemical reaction such as thermal decomposition or partial oxidation.

<Temperature control device>
The temperature adjusting device 2 includes, for example, a temperature-decreasing tower, a heat exchanger, a cooling chamber having a water-cooled wall or an air-cooled wall, and the like, and a downstream moving bed type tar removing device 5, a fixed bed type tar removing device 7 and a sulfur compound removing device. The temperature of the biomass gas introduced into 9 is adjusted to a predetermined temperature.
The predetermined temperature here is a temperature at which the atmosphere temperature of the remover layer is suitable for tar removal by the biomass gas introduced into the moving bed type tar removing device and the fixed bed type tar removing device by the biomass gas. In addition, the biomass gas introduced into the sulfur compound removing device 9 is a temperature at which the atmospheric temperature of the remover layer in the sulfur compound removing device is suitable for removing sulfur compounds.

The atmosphere temperature of the remover layer suitable for tar removal is 130 ° C to 500 ° C, more preferably 200 ° C to 400 ° C, and even more preferably 300 ° C. The reason that the atmospheric temperature range of the remover layer is set to 130 ° C. to 500 ° C. is that if the atmospheric temperature of the remover layer is lower than 130 ° C., the tar is likely to condense and adhere to the inside of the apparatus, causing trouble. This is because pyrolysis of activated carbon occurs when the temperature is higher than 500 ° C. In addition, the strength of maintaining the remover layer may be insufficient, which may hinder gas flow. Also, the atmospheric temperature range of the remover layer is more preferably 200 ° C. to 400 ° C., and even more preferably 300 ° C. The tar removal ability of activated carbon is sufficiently high in this temperature range, and the usefulness of biomass gas This is because there is no influence on the gas component.

Moreover, the predetermined temperature for the atmospheric temperature of the removal agent layer suitable for sulfur compound removal is 160 ° C to 500 ° C.
The atmospheric temperature range of the remover layer is set to 160 ° C. to 500 ° C. when the atmospheric temperature of the remover layer is lower than 160 ° C., the conversion reaction of COS + H ₂ O → H ₂ S + CO in the sulfur compound removing device 9 This is because the rate in the decomposition reaction of H ₂ S and COS is remarkably reduced, and the sulfur compound removal efficiency is reduced. Further, because the corrosion caused by _{H 2} S occurs.
On the other hand, if the atmospheric temperature of the remover layer is higher than 500 ° C., the carbonaceous remover is thermally decomposed. In addition, the strength for maintaining the carbonaceous remover layer may be insufficient, which may hinder gas flow.

  The atmospheric temperature of the remover layer is more preferably 300 ° C. to 450 ° C., and further about 450 ° C. is most preferable because the decomposition reaction of the sulfur compound occurs actively. This is because the activated carbon has a sufficiently high ability to remove sulfur compounds in this temperature range and does not affect the useful gas components of the biomass gas. Moreover, the liquid fuel synthesis efficiency can be improved by utilizing the sensible heat of the purified gas.

The temperature control in the temperature adjusting device 2 is performed by the temperature detecting device that detects the removal layer atmosphere temperature in the moving bed type tar removing device 5, the fixed bed type tar removing device 7 and the sulfur compound removing device 9 in the device. May be performed based on the temperature detected by this.
In addition, when the gasification furnace is provided with a device for reducing and adjusting the temperature of the biomass gas so as to be a predetermined temperature, such as a water cooling wall or a heat recovery boiler, When the gasification operation is performed so as to reach the temperature, the temperature adjusting device is not always necessary.

<Dust remover>
The dust remover 3 removes dust in biomass gas, and specifically includes a cyclone, a filter, a moving bed type dust remover, and the like.
In addition, since the moving bed type tar removing device 5 installed on the downstream side of the dust removing device 3 has a dust removing capability, the dust in the gas can be removed by the moving bed type tar removing device 5. Therefore, it is not essential to separately provide the dust removing device 3 upstream of the moving bed type tar removing device 5. However, by providing the dust removing device 3 separately, it is possible to prevent clogging due to dust of the moving bed type tar removing device 5 and to prevent a reduction in tar removal efficiency due to clogging due to dust.
Further, when almost no dust is generated in the biomass gas due to the properties of the biomass and the type of the gasification furnace, it is not necessary to provide a dust removing device.

<Moving bed type tar removal device>
The moving bed type tar removing device 5 is provided on the downstream side of the dust removing device 3 to remove tar in the biomass gas.
As shown in FIG. 2, the moving bed type tar removing apparatus 5 includes a cylindrical main body 12 and an activated carbon layer 13 as a removing agent layer formed therein as main components. A gas inlet 15 is formed on the lower side surface of the main body 12, and a gas outlet 17 is formed on the upper side surface of the main body 12. An activated carbon inlet 19 for introducing activated carbon is provided at the upper end of the main body 12, and an activated carbon outlet 21 for discharging activated carbon from which tar has been removed is provided at the lower end of the main body 12. That is, the activated carbon forming the activated carbon layer 13 is sequentially discharged from the lower one, and new activated carbon is supplied upward. That is, the activated carbon layer 13 is a moving layer in which the layer sequentially moves downward by discharge and supply.
The activated carbon layer 13 is formed between the gas inlet 15 and the gas outlet 17 in the main body, and a gas introduced from the gas inlet 15 is dispersed immediately below the activated carbon layer 13 so as to pass through the activated carbon layer 13. A disperser 23 is provided.

The activated carbon forming the activated carbon layer 13 is preferably activated carbon having a particle size of 2 to 10 mm. This is because most of the tar contained in the biomass gas is heavy tar, and activated carbon having the above-described properties is preferable for efficiently removing heavy tar.
The moving bed type tar removal device 5 is located upstream of the tar removal step and mainly aims to remove heavy tar contained in a large amount of biomass gas. Activated carbon having suitable properties, clogging, etc. This is a moving bed type.
In addition, heavy tar means a thing with a relatively high dew point temperature and mainly polycyclic aromatic compounds.

The activated carbon of the activated carbon layer 13 preferably has a specific surface area of 250 m ² / g or more. When the specific surface area is smaller than 250 m ² / g, the tar removing ability in the biomass gas is not sufficient. The activated carbon of the activated carbon layer 13 preferably has an average pore size of 0.1 nm or more. If the average pore diameter is smaller than 0.1 nm, the pore diameter is too small, so that a large molecular weight such as tar cannot enter the pores.
Moreover, it is preferable that the atmospheric temperature of the activated carbon layer 13 shall be 130 to 500 degreeC as above-mentioned by adjusting biomass gas temperature with the temperature control apparatus 2, and 200 to 400 degreeC is more preferable. If the activated carbon layer 13 satisfies such conditions, only the tar contained in the biomass gas is effectively removed, and a purified gas containing almost no tar can be produced. In addition, when the activated carbon layer 13 satisfies the above conditions, H ₂ , CO, and hydrocarbons contained in the biomass gas pass through the voids of the activated carbon layer 13, so that useful gas does not decrease.
In addition to adjusting the temperature of the biomass gas introduced into the remover layer as described above, a jacket is provided around the remover layer, or a heat exchanger is installed inside the remover layer. The removal agent layer may be provided by heating or cooling from the outside or the inside.

<Fixed bed tar removal device>
The fixed bed type tar removing device 7 is configured to remove light tar and heavy tar that has not been removed by the moving bed type tar removing device 5 from the biomass gas from which the heavy tar is mainly removed by the moving bed type tar removing device 5. The portion is removed so that the gas utilization facility 11 can be used without any problem. As an example of the fixed bed type tar removing device 7, there is a structure in which an activated carbon cartridge 27 is installed inside a main body 25 as shown in FIG. 3. As shown in FIG. 4, the activated carbon cartridge 27 has an activated carbon layer 29 formed by filling activated carbon therein and a treatment gas introduction space 31, and the activated carbon layer 29 and the introduction space 31 are viewed in plan view. It is arranged in a staggered pattern.

The activated carbon layer 29 is a fixed layer, and the filling rate of activated carbon is higher than the filling rate of the moving bed type tar removing device 5. Moreover, it is preferable that the particle size of the activated carbon which forms the activated carbon layer 29 is 1-3 mm. The reason is that the fixed bed type tar removing device 7 is intended to remove the remaining heavy tar and light tar that could not be completely removed by the moving bed type tar removing device 5. The activated carbon having the above properties is preferred.
The light tar has a relatively low dew point temperature and is mainly composed of heterocyclic compounds and aromatic compounds.

Further, as described in the moving bed type tar removing device 5, in order to effectively remove only the tar contained in the biomass gas, the fixed layer type tar removing device 7 also uses the activated carbon layer 29 in the ratio. The surface area is 250 m ² / g or more, the average pore diameter is 0.1 nm or more, and the atmospheric temperature of the activated carbon layer 29 is preferably 130 ° C. to 500 ° C., more preferably 200 ° C. to 400 ° C.
Moreover, by adjusting the atmospheric temperature of the activated carbon layer 29 of the fixed bed type tar removing device 7 to be lower than the atmospheric temperature of the activated carbon layer 13 of the moving bed type tar removing device 5, tars having different dew point temperature regions can be removed. This is preferable because it can be effectively removed.

In the fixed bed type tar removing device 7 configured as described above, the gas from which most of the tar has been removed by the moving bed type tar removing device 5 is introduced into the main body from the gas inlet 25a of the main body 25, and the activated carbon cartridge After passing through the activated carbon layer 29 via the introduction space 31 of 27, the remaining tar is removed and discharged from the gas outlet 25b (see FIG. 4).
A fixed bed type tar removing device other than the above cartridge type fixed bed type tar removing device may be used. For example, in the moving bed type tar removing apparatus 5 shown in FIG. 2, the activated carbon layer 13 may be used as a fixed layer without being moved continuously. In order to use the activated carbon layer 13 as a fixed layer, for example, gas is flowed from the lower side to the upper side of the activated carbon layer 13 to remove tar with activated carbon, and when tar removal is performed for a predetermined time, the activated carbon outlet 21 The activated carbon having a reduced tar removing ability is discharged from the activated carbon, and new activated carbon corresponding to the discharged amount is introduced from the activated carbon inlet 19 to update the activated carbon layer 13.

<Sulfur compound removal device>
The sulfur compound removing device 9 is provided on the downstream side of the fixed bed type tar removing device 7 to remove sulfur compounds in the biomass gas.
As shown in FIG. 5, the sulfur compound removing device 9 includes a cylindrical main body 33 and an activated carbon layer 35 as a removing agent layer formed therein as main components.
A gas inlet 37 is formed on the lower side surface of the main body 33, and a gas outlet 39 is formed on the upper side surface of the main body 33. An activated carbon inlet 41 for introducing activated carbon is provided at the upper end of the main body 33, and an activated carbon outlet 43 for discharging activated carbon from which sulfur compounds have been removed from biomass gas is provided at the lower end of the main body 33. And constitutes a fixed bed type removal device.
The activated carbon layer 35 is formed between the gas inlet 37 and the gas outlet 39 in the main body, and the biomass gas introduced from the gas inlet 37 is dispersed and passed through the activated carbon layer 35 immediately below the activated carbon layer 35. Disperser 45 is provided.

In the sulfur compound removing device 9, biomass gas is flowed from the lower side to the upper side of the activated carbon layer 35, and the sulfur compound is removed by activated carbon. When the sulfur compound removal is performed for a predetermined time, the activated carbon having a reduced sulfur compound removing ability is discharged from the activated carbon outlet 43, and new activated carbon corresponding to the discharged amount is introduced from the activated carbon inlet 41 to update the activated carbon layer 35. .
In addition, a cartridge type fixed layer type removing device in which an activated carbon cartridge is installed inside the main body or a fixed layer type removing device using a single layer or a plurality of activated carbon layers having a predetermined layer thickness may be used.

The activated carbon of the activated carbon layer 35 preferably has a specific surface area of 250 m ² / g or more and an average pore diameter of 0.1 nm or more.
Moreover, it is preferable that the atmospheric temperature of the activated carbon layer 35 shall be 160 degreeC-500 degreeC as above-mentioned by adjusting biomass gas temperature with the temperature control apparatus 2, and 300 degreeC-450 degreeC is more preferable. If the activated carbon layer 35 satisfies such conditions, only the sulfur compound contained in the biomass gas can be effectively removed, and a purified gas containing almost no sulfur compound can be produced. In addition, when the activated carbon layer 35 satisfies the above conditions, H ₂ , CO, and hydrocarbons contained in the biomass gas pass through the voids of the activated carbon layer 35, so that useful gas does not decrease.

  In addition, when making the removal agent layer atmosphere temperature of the sulfur compound removal device 9 higher than the tar removal agent layer atmosphere temperature of the upstream tar removal device, heat exchange is performed with the burner exhaust gas or the exhaust gas from the gas utilization equipment. The biomass gas introduced into the sulfur compound removing device 9 may be heated.

  Further, the sulfur compound removing device 9 is not limited to the above fixed bed type removing device, and a moving bed type removing device may be used. In the moving bed type removal device, the activated carbon forming the activated carbon layer 35 is always discharged sequentially from the lower one, and new activated carbon is supplied upward.

<Gas equipment>
A gas utilization facility is a facility that uses biomass gas from which tar has been removed as gas fuel, and examples thereof include a gas engine, a gas turbine, a boiler, a burner combustor used in an industrial furnace, a fuel cell, and the like.
A cooler 8 for cooling the purified biomass gas in the downstream of the fixed bed tar removing device 7 is provided as necessary, and adjusted to a temperature suitable for the gas utilization facility.

In the present embodiment configured as described above, the biomass gas generated in the gasification furnace 1 is reduced to a predetermined temperature by the temperature control device 2. The temperature at this time is preferably set so that the atmosphere of the remover layer in the moving bed type tar removing device 5 and the fixed bed type tar removing device 7 is 200 ° C to 400 ° C. The dust removed by the dust removing device 3 is removed from the biomass gas whose temperature has been reduced to a predetermined temperature by the temperature adjusting device 2. The biomass gas from which dust has been removed by the dust removing device 3 is introduced from the gas inlet 15 into the moving bed tar removing device 5. The biomass gas introduced into the moving bed type tar removing device 5 is dispersed by the disperser 23 and passes through the activated carbon layer 13. At this time, the activated carbon of the activated carbon layer 13 has a specific surface area of 250 m ² / g or more, an average pore diameter of 0.1 nm or more, and further, the removal layer atmosphere temperature is adjusted to about 300 ° C. Only the tar contained in the biomass gas is removed by the activated carbon layer 13 and purified effectively.

In the moving bed type tar removing device 5, gas flows from the lower side of the activated carbon layer 13 toward the upper side, so that tar is removed in order from the lower side activated carbon. Therefore, the activated carbon having a reduced tar removing ability is discharged from the activated carbon discharge port 21, and new activated carbon corresponding to the discharge is introduced from the activated carbon introduction port 19 to sequentially move the activated carbon layer 13 downward. By doing so, the activated carbon layer 13 always forms a moving layer while maintaining a predetermined layer thickness, and does not reduce the tar removal ability.
Thus, by installing the moving bed type tar removing device 5 on the upstream side, heavy tar in the biomass gas can be effectively removed without causing clogging in the removal layer.

  Biomass gas from which tar has been almost removed by the moving bed type tar removing device 5 is introduced into the fixed bed type tar removing device 7, so that light tar and heavy tar that cannot be completely removed by the moving bed type tar removing device 5. The remaining part is removed.

  The biomass gas from which tar has been removed by the moving bed type tar removing device 5 and the fixed bed type tar removing device 7 is introduced into the sulfur compound removing device 9 from the gas inlet 15. The biomass gas introduced into the sulfur compound removing device 9 is dispersed by the disperser 45 and passes through the activated carbon layer 35.

At this time, the sulfur compounds of H ₂ S and COS contained in the biomass gas are adsorbed and decomposed on the activated carbon and captured.
In particular, since the atmosphere temperature of the activated carbon layer 35 is set to 160 ° C. or higher, the conversion reaction and the decomposition reaction represented by the following formulas of H ₂ S and COS are promoted, and the decomposed sulfur is captured by the activated carbon layer 13. The
COS + H ₂ O → H ₂ S + CO
H ₂ S → H ₂ + S
COS → CO + S

In particular, it is most preferable that the temperature at this time is such that the atmosphere of the removing agent layer in the sulfur compound removing device 9 is about 450 ° C. By adjusting the remover layer atmospheric temperature to about 450 ° C., the decomposition reaction of H ₂ S and COS is most promoted, and only the sulfur compound contained in the biomass gas is effectively removed by the activated carbon layer 13. Purified.
When the temperature of the removal agent layer atmosphere is about 450 ° C., when the temperature is higher than the temperature of the upstream tar removal agent layer (about 400 ° C. in this example), the upstream of the sulfur compound removal device 9 A heater that heats biomass gas by exchanging heat with burner exhaust gas or exhaust gas from gas utilization equipment may be provided on the side.

  In the sulfur compound removing device 9, gas flows from the lower side to the upper side of the activated carbon layer 35, so that the sulfur compound is sequentially removed from the lower side activated carbon. When the activated carbon discharge port 43 is opened, the activated carbon is discharged sequentially from the activated carbon on the lower side subjected to adsorption and decomposition capture, which is efficient.

  The biomass gas from which the sulfur compounds have been removed by the sulfur compound removing device 9 after the tar removal by the moving bed type tar removing device 5 and the fixed bed type tar removing device 7 is temperature-adjusted by the cooler 10 as necessary. Then, it is introduced into the gas utilization facility 11 and used as gas fuel or the like in the gas utilization facility 11.

As described above, in the present embodiment, when purifying biomass gas, the moving bed type tar removing device 5 is arranged upstream and the fixed bed type tar removing device 7 is arranged downstream, The treatment of a large amount of washing water as in the case where tar is removed by a wet removal apparatus as in the prior art becomes unnecessary, and since it is a dry type, the equipment scale is reduced in size and cost is reduced.
Further, since the moving bed type tar removing device 5 is arranged on the upstream side, the activated carbon having a reduced tar removing ability can be renewed, so that smooth operation is possible without causing clogging even when removing a large amount of tar on the upstream side. it can.

Moreover, the activated carbon which forms the activated carbon layer 13 of the moving bed type tar removing apparatus 5 has a particle diameter of 2 to 10 mm, and the activated carbon which forms the activated carbon layer 29 of the fixed bed type tar removing apparatus 7 has a particle diameter of 1 to 3 mm, heavy tar is effectively removed by the moving bed type tar removing device 5 on the upstream side, and light tar and heavy are removed by the fixed bed type tar removing device 7 on the downstream side. The residue of the quality tar is effectively removed, and the tar can be efficiently removed as a whole.
In this way, the combination of removal devices suitable for tar properties makes it possible to remove both heavy tar and light tar by using a small and compact device. it can.
In addition, since the specific surface area of the activated carbon of the activated carbon layer is 250 m ² / g or more, the average pore diameter is 0.1 nm or more, and the atmosphere temperature of the activated carbon layer is adjusted to about 300 ° C., it is included in the biomass gas. Only the tar is removed by the activated carbon layer and effectively purified.

Further, as described above, in the present embodiment, since the dry-type sulfur compound removing device 9 including the activated carbon layer 35 is employed as the sulfur compound removing device, the wet-type removing device shown in the conventional example is used. Such a treatment of the washing water is unnecessary, and the equipment scale is reduced in size and cost.
Further, since the removal agent layer atmosphere temperature can be adjusted to 160 ° C. to 500 ° C., the decomposition reaction of the sulfur compound contained in the biomass gas is promoted, and only the sulfur compound is removed by the activated carbon layer 35. Effectively purified.

  In the above-described embodiment, biomass gas is described as a gasification gas that is gasified thermochemically, but the same effect can be obtained for a gasification gas obtained by gasifying fossil fuel or waste.

  In the above embodiment, as an example of the moving bed type tar removing device 5, as shown in FIG. However, the present invention is not limited to this, for example, as shown in FIG. 6, two moving layers filled with activated carbon are provided in a cylindrical space whose side is partitioned by a net or louver as shown in FIG. The upstream moving layer 13a and the downstream moving layer 13b may be used. In FIG. 6, the same or corresponding parts as those in the moving bed type tar removing device 5 shown in FIG. The biomass gas introduced from the gas inlet 15 passes through the upstream moving bed 13a, further passes through the downstream moving bed 13b, and is discharged from the gas outlet 17. In the case of such a two-layer structure, the upstream moving layer 13a mainly focuses on dust removal, and the activated carbon cutting speed is increased to smoothly renew the activated carbon. The downstream moving layer 13b mainly focuses on tar removal. It is preferable to slow down the cutting speed of activated carbon. In addition, when the two-layer structure is used in this way, the upstream moving layer 13a may be specialized exclusively for the dust removal function, and sand, slag particles, ceramic particles, or the like may be used as the filler.

  Moreover, in the said embodiment, although the example which provided one fixed bed type tar removal apparatus 7 in one line was shown, as shown in FIG. 7, several fixed bed type tar removal apparatuses are provided in one line. 7, and if the tar removal ability of one fixed bed type tar removing device 7 is lowered, the gas flow may be switched to another fixed bed type tar removing device 7 for use. By doing in this way, a process is not interrupted also at the time of replacement | exchange of the activated carbon of the fixed tar removal apparatus 7. FIG.

  Further, as shown in FIG. 7, a heater 7b is provided around the activated carbon layer 7a in the fixed bed type tar removing device 7, and a part of the purified gas is introduced into the heater 7b and this is used as a fuel gas by a burner. The activated carbon layer 7a may be heated in an inert gas atmosphere or under reduced pressure to desorb tar, which is then introduced into the gasification furnace 1 and gasified for use as a useful gas. In this way, it is unnecessary to replace the activated carbon or the frequency thereof is reduced, and the desorbed tar can be used effectively.

  In the above embodiment, activated carbon is given as an example of a carbon agent for removing tar. However, in addition to activated carbon, activated coke, coal, coke, charcoal, graphite, carbon black, fullerene, carbon nanotube, derived from organic matter Can be used.

Moreover, in said embodiment, the example which used activated carbon as a sulfur compound removal agent of the sulfur compound removal apparatus 9 was shown.
However, the present invention is not limited to this, and in order to promote the decomposition reaction of H ₂ S and COS, as a sulfur compound remover, 1A group, 1B group, 2A group, 2B group, 6 It is also preferable to use a carbonaceous removal agent in which at least one of the elements of group 8 and group 8 is supported on a carbonaceous material, for example, activated carbon. By supporting at least one of the elements of Group 1A, Group 1B, Group 2A, Group 2B, Group 6 and Group 8, the sulfur oxide can be decomposed by the catalytic action of the element.

For example, when iron (Fe) is supported, Fe promotes the reaction of the following formula.
H ₂ S → H ₂ + S
COS → CO + S
Moreover, there exists an effect | action which capture | acquires the sulfur (S) produced | generated when Fe decomposed | disassembled. This is because the metal Fe becomes FeS, and iron oxide is trapped by a reaction such that O in Fe ₂ O ₃ exchanges with S, and is trapped as S in the pores of the carbonaceous removal agent.

In the above example, as the carbonaceous remover, an example using a carbonaceous remover carrying at least one of the elements of Group 1A, 1B, 2A, 2B, 6 and 8 of the periodic table of elements is used. However, even when carbonized raw materials containing the above elements, for example, residues obtained by gasifying thermochemically biomass (biomass char) or residues obtained by dry distillation gasification of low quality coal such as lignite (brown coal char) examples and has an action to promote the decomposition reaction of H _{2 S} and COS as well.

Moreover, as an example of the sulfur compound removing device 9, the fixed layer type removing device and the cartridge type fixed layer removing device filled with activated carbon are shown in the above embodiment, but the present invention is not limited to this. Alternatively, other fixed layer type or moving layer type removing devices may be used.
Further, the carbonaceous material supporting at least one of the elements of Group 1A, 1B, 2A, 2B, 6 and 8 of the periodic table of elements is not limited to activated carbon, but also activated carbon. In addition, carbonaceous materials such as activated coke, coal, coke, charcoal, graphite, carbon black, fullerene, carbon nanotubes, and organic-derived carbides can be used.
In addition, carbonaceous materials such as activated coke, coal, coke, charcoal, graphite, carbon black, fullerene, carbon nanotube, and organic-derived carbide can be used as the sulfur compound remover.
Moreover, the shape of the sulfur compound removing agent for removing the sulfur compound may be powder, granule, pellet, plate, honeycomb or the like, or may be supported on a carrier of another substance.

[Embodiment 2]
The gas purification apparatus according to the present embodiment is provided with a wet tar removal apparatus in place of the fixed bed type tar removal apparatus 7 in the first embodiment. And since the temperature of biomass gas falls by passing this wet tar removal apparatus by having installed the wet tar removal apparatus, it seems that the heater which raises the temperature of biomass gas is provided in the downstream of a wet tar removal apparatus. It is a thing. Other configurations are the same as those of the embodiment shown in FIG.
Hereinafter, details of the apparatus newly provided in this embodiment will be described.

<Wet tar removal device>
The wet tar removing device removes further tar from the biomass gas from which tar has been almost removed by the moving bed type tar removing device 5 to such an extent that it can be used in a gas utilization facility without any problem. As an example of the wet tar removing device, there is a wet electrostatic precipitator 47 as shown in FIG.
As shown in FIG. 8, the wet electric dust collector 47 has a large number of flat plate-like dust collecting electrodes 53 arranged at equal intervals along a vertical plane in a casing 51 that encloses the entire device. A discharge electrode 55 is disposed therebetween. A fixing fitting 57 is provided on the upper part of the dust collecting electrode 53, and the dust collecting electrode 53 is fixed in a state of being suspended in the casing 51 through the fixing fitting 57.
On the other hand, the discharge electrode 55 is supported by a support insulator 61 in an insulator chamber 59 provided in the upper part of the casing 51, and the discharge electrode 55 is fixed on both sides of each dust collecting electrode 53, whereby the discharge electrode 55 is fixed in the casing 51. A dust collection space 63 is formed.

  A nozzle 65 for injecting cleaning water is disposed on the upper portion of the casing 51, and a water film is formed on the surface of the dust collection electrode 53 (dust collection electrode surface) by the water jetted from each nozzle 65. That is, the water discharged from the nozzle 65 reaches the dust collecting electrode surface, flows downward while falling on the hopper 67 while forming a water film on the dust collecting electrode surface, and is discharged to the outside by the discharging device 69.

  In the wet electric dust collector 47 configured as described above, the processing gas that has passed through the mobile tar removing device 5 is introduced into the dust collecting space 63 from the gas inlet 71. When a negative DC high voltage is applied to the discharge electrode 55 from the power supply device (not shown) via the support insulator 61, a negative ion current starts to flow (corona discharge) toward the dust collection electrode 53 (positive ground electrode). Tar and other mists contained in the processing gas are charged by negative ions and are attracted to the surface of the dust collection electrode by the Coulomb force generated by the electric field between the electrodes. Thus, tar and mist are washed down together with the water film, and clean gas from which tar and the like have been removed is discharged from the gas outlet 73.

  The wet tar removing device can use a wet scrubber in addition to the wet electrostatic precipitator 47 described above.

<Heater>
As the heater, a heater that heats biomass gas by exchanging heat with burner exhaust gas or exhaust gas from gas utilization equipment can be used.

In the second embodiment configured as described above, the biomass gas from which most of the tar has been removed by the moving bed type tar removing device 5 is introduced into the wet electrostatic precipitator 47 to further remove the tar.
In addition, although the washing waste water containing tar discharged from the wet electrostatic precipitator 47 is subjected to a predetermined treatment, the amount of the treated water is small, and the tar is removed only by the wet tar removal device as in the past. Compared to the case of cleaning water treatment, an extremely small amount is sufficient.
After tar removal is performed by the wet electrostatic precipitator 47, the biomass gas is introduced into the gas utilization facility 11 and used as gas fuel or the like in the gas utilization facility 11.

  As described above, in the present embodiment, when purifying biomass gas, the moving bed type tar removing device 5 is arranged upstream, and the wet tar removing device is arranged downstream thereof. As in the case where only a wet tar removal device is installed, it is not necessary to process a large amount of washing water, and the moving bed type tar removal device removes most of the tar. Cost reduction is realized.

[Embodiment 3]
In the gas purification apparatus of the present embodiment, the dry bed type tar removal apparatus 5 and the fixed bed type tar removal apparatus 7 are both used as the tar removal apparatus in the first embodiment. A wet tar removing device is used. As the wet tar removing device, for example, the wet electrostatic precipitator 47 shown in FIG. 8 or a wet scrubber may be used.

That is, the gas purification apparatus of the present embodiment is such that tar is removed by a wet tar removal apparatus, and sulfur compounds are removed by a dry sulfur compound removal apparatus 9 filled with activated carbon or the like.
By adopting such a configuration when the tar content in the biomass gas is high, the tar can be sufficiently removed by the wet tar removal device, and further, the sulfur compound is removed by the wet removal device. Thus, the apparatus can be simplified and tar and sulfur compounds can be efficiently removed.

[Embodiment 4]
The gas purifying apparatus of the present embodiment uses two apparatuses, the moving bed type tar removing apparatus 5 and the fixed bed type tar removing apparatus 7, as the tar removing apparatus in the first embodiment. Of these two apparatuses, The fixed bed type tar removing device 7 is omitted.
When the tar content in the biomass gas is lower than when the first to third embodiments are applied, the tar removal device can be simplified by adopting such a configuration.

[Embodiment 5]
The gas purification apparatus according to the present embodiment is different from the apparatus in which the two apparatuses of the moving bed type tar removing apparatus 5 and the fixed bed type tar removing apparatus 7 are used as the tar removing apparatus in the first embodiment. Except that only the fixed bed type tar removing device 7 is used as the tar removing device.

When the tar content in the biomass gas is relatively low, by adopting such a configuration, the apparatus becomes compact and tar and sulfur compounds can be efficiently removed.
In this case, the removal agent layers of the fixed bed type tar removing device 7 and the sulfur compound removing device 9 may be provided in one device. In this way, the apparatus can be made more compact.

[Embodiment 6]
The gas purifying apparatus of the present embodiment uses the three apparatuses of the moving bed type tar removing apparatus 5, the fixed bed type tar removing apparatus 7 and the fixed bed type sulfur compound removing apparatus 9 in the first embodiment. The removal agent layers of the fixed bed type tar removing device 7 and the fixed bed type sulfur compound removing device 9 are provided in one device to form a tar / sulfur compound removing device.
In this way, the device can be made compact.

[Embodiment 7]
The gas purification apparatus of the present embodiment has a tar remover / sulfur compound remover mixed layer filled with the tar remover and sulfur compound remover shown in Embodiment 1 as a remover layer. . The removal agent layer may be the moving bed type shown in FIG. 2 or the fixed layer type shown in FIG.
The gas purification apparatus of the present embodiment is suitable when the tar content in the biomass gas is relatively low, the apparatus becomes compact, and tar and sulfur compounds can be efficiently removed.

[Embodiment 8]
The gas purification apparatus of the present embodiment is provided with a moving bed type tar removal apparatus upstream of the apparatus using the tar removal agent / sulfur compound removal agent mixed layer shown in the seventh embodiment as a removal agent layer. .
By setting it as such a structure, even when the tar content rate in biomass gas is high, a tar and a sulfur compound can be removed efficiently.

  In the above-described embodiment, the gas purification apparatus for biomass gas has been described. However, the fossil fuel or waste other than biomass gas is converted into gas by thermochemical gasification, that is, by pyrolysis reaction or partial oxidation reaction. The same applies to gas purification of the resulting gas.

An experiment was conducted to confirm the tar removal effect of the mobile tar removing device 5 and the fixed tar removing device 7 shown in the first embodiment, and the results are shown below. The specifications of the moving bed type tar removing device 5 and the fixed bed type tar removing device 7 are those shown in the above embodiment, and the activated carbon used has a specific surface area of 250 m ² / g or more. The ambient temperature of the layer 13 is 330 ° C. in the moving bed type tar removing device 5 and 270 ° C. in the fixed bed type tar removing device 7.

The tar concentration in the biomass gas introduced into the moving bed type tar removing device 5 was 20 g / Nm ³ , but the tar concentration in the gas discharged from the moving bed type tar removing device 5 was 2 g / Nm ³ . 90% of tar was removed by the moving bed type tar removing device 5.
Further, the biomass gas introduced into the fixed bed type tar removing device 7 with a tar concentration of 2 g / Nm ³ has a tar concentration of 0.01 g / Nm ³ at the outlet side of the fixed bed type tar removing device 7, and is a fuel for a gas engine. As a result, it was able to be removed to a concentration without any problem.

Next, an experiment for confirming the sulfur compound removal efficiency of the sulfur compound removing apparatus 9 shown in the first embodiment was performed.
The biomass gas in which 100 ppm of H ₂ S and COS are contained in the biomass gas from which tar has been removed is circulated through the removal agent layer filled with the various carbonaceous removal agents shown in Embodiment 1, and the outlet gas composition of the removal agent layer And the removal rate was measured.
Table 1 summarizes the measurement results in a table. In Table 1, the specific surface area of each removal agent is also described.

As can be seen from Table 1, the activated carbon, biomass char, lignite char, and iron-supported lignite char all have a H ₂ S and COS removal rate of 100%. From this, activated carbon, biomass char, lignite char, iron-supported lignite char can be used as a remover, and by setting the ambient temperature to 400 ° C, H ₂ S and COS can be effectively removed, which is a problem as a gas engine fuel. It is shown that it can be removed even to a concentration without any.
The biomass char shown in Table 1 is made from wood chips. The iron-supporting lignite char is prepared by immersing the lignite char in an aqueous solution containing the Fe element and drying it.

Next, in order to confirm the transition of the removal rate of the activated charcoal, biomass char, lignite char, and iron-supported lignite char through the passage of time, the various removal agents H ₂ S and COS after 1000 hours have passed since the start of gas passage. The removal rate was measured. The measurement results are shown in Table 2.

As can be seen from Table 2, the activated carbon is reduced in both H ₂ S and COS removal rates after 1000 hours. This is presumed to be because activated carbon has mainly removed H ₂ S and COS by adsorption, and its adsorption power has decreased with time.
In contrast, lignite char, a reduction in the removal rate of _{H 2} S and COS is small, _{H 2} S and COS removal rate after the lapse of 1000 hours is higher than the activated carbon. The reason for this is considered to be that the Ca component derived from the ash remains in the lignite char, and this Ca component acts as a catalyst to promote the decomposition reaction of H ₂ S and COS. That is, when accompanied by a decomposition reaction, mainly the decomposed S is trapped on the surface of the removing agent, so that the trapping power does not decrease.
Moreover, in iron carrying | support lignite char, since decomposition | disassembly reaction is accelerated | stimulated more by the catalytic effect | action of the iron part carried | supported in addition to said Ca part, the fall of the removal rate by time passage can be suppressed further.

Moreover, even in the biomass char, the removal rate of H ₂ S and COS after 1000 hours is higher than that of the activated carbon even if it does not reach the lignite char and the iron-supported lignite char. This is because the alkali metal or alkaline earth metal contained in the wood chip, which is the raw material of biomass char, also remains in the biomass char, and these metals decompose catalytically in the decomposition reaction of H ₂ S and COS. This is because the reaction is promoted.

Next, using activated carbon as a removing agent, an experiment was conducted to examine the influence of the atmospheric temperature on the removal rate. In the experiment, the removal rates of H ₂ S and COS were examined when the atmospheric temperature was changed to 140 ° C., 160 ° C., 200 ° C., 300 ° C., 400 ° C., 450 ° C. The results are shown in Table 3.

As can be seen from Table 3, when the ambient temperature is 140 ° C., the removal rate of H ₂ S and COS is extremely low. This is because when the ambient temperature is lower than 160 ° C., the decomposition reaction cannot be expected.
On the other hand, when the ambient temperature is 160 ° C. or higher, particularly 400 ° C. or higher, the removal rate of H ₂ S and COS is extremely high. This is because the decomposition reaction of H ₂ S and COS becomes active when the atmospheric temperature is set to 160 ° C. or higher.
From the above, it has been demonstrated that it is preferable to set the atmosphere temperature of the remover layer to 160 ° C. or higher when removing H ₂ S and COS.

It is explanatory drawing explaining the whole structure of the gas purification apparatus which concerns on one embodiment of this invention. It is explanatory drawing of the moving bed type | mold tar removal apparatus which is a part of gas purification apparatus shown in FIG. It is explanatory drawing of the fixed bed type | mold tar removal apparatus which is a part of gas purification apparatus shown in FIG. It is explanatory drawing explaining a part of FIG. 3 in detail. It is explanatory drawing of the sulfur compound removal apparatus which is a part of gas purification apparatus shown in FIG. It is explanatory drawing of the other aspect of the moving bed type tar removal apparatus shown in FIG. It is explanatory drawing of the other aspect of the gas purification apparatus shown in FIG. It is explanatory drawing of the wet tar removal apparatus used for other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gasification furnace 2 Temperature control device 3 Dust removal device 5 Moving bed type tar removal device 7 Fixed bed type tar removal device 9 Sulfur oxide removal device 10 Cooler 11 Gas utilization equipment

Claims (13)

An apparatus for purifying gasified gas obtained by thermochemical gasification,
A tar removal device having a tar removal agent layer filled with a tar removal agent that removes tar by passing the gasification gas; and a gas removal gas disposed downstream of the tar removal device to pass the gasification gas. A sulfur compound removing device having a sulfur compound remover layer filled with a sulfur compound remover that removes H ₂ S and / or COS;
The tar removal device includes a moving bed type tar removal device that renews the tar removal agent layer by moving the tar removal agent layer, and the tar removal agent layer disposed on the downstream side of the moving bed type tar removal device. There will be a fixed bed tar removal device comprising a fixed,
The said sulfur compound removal apparatus consists of a fixed bed type sulfur compound removal apparatus by which a sulfur compound removal agent layer is fixed, The gas purification apparatus characterized by the above-mentioned. An apparatus for purifying gasified gas obtained by thermochemical gasification,
A tar removal device having a tar removal agent layer filled with a tar removal agent that removes tar by passing the gasification gas; and a gas removal gas disposed downstream of the tar removal device to pass the gasification gas. A sulfur compound removing apparatus having a sulfur compound removing agent layer filled with a sulfur compound removing agent that removes H ₂ S and / or COS, and the atmospheric temperature of the tar removing agent layer is 130 to 500 ° C. Temperature adjusting means for adjusting the temperature of the gasification gas,
The tar remover is activated carbon, and the tar remover includes a moving bed type tar remover that moves the tar remover layer to renew the tar remover layer, and the sulfur compound remover is a sulfur compound. A gas purification apparatus comprising a fixed bed type sulfur compound removing apparatus having a removing agent layer fixed thereto. An apparatus for purifying gasified gas obtained by thermochemical gasification,
A tar removal device having a tar removal agent layer filled with a tar removal agent that removes tar by passing the gasification gas; and a gas removal gas disposed downstream of the tar removal device to pass the gasification gas. A sulfur compound removing device having a sulfur compound remover layer filled with a sulfur compound remover that removes H ₂ S and / or COS;
The tar removal device includes a fixed bed type tar removal device in which the tar removal agent layer is fixed, and the sulfur compound removal device includes a fixed layer type sulfur compound removal device in which a sulfur compound removal agent layer is fixed. A gas purifier characterized by comprising: An apparatus for purifying gasified gas obtained by thermochemical gasification,
A moving bed type tar removal that has a tar removal agent layer that is filled with a tar removal agent that passes through the gasification gas and removes the tar, and moves the tar removal agent layer to renew the tar removal agent layer. Equipment,
A tar removal agent layer disposed downstream of the tar removal device for removing tar that has not been removed by the tar removal device; and a gas removal gas disposed downstream of the tar removal agent layer to allow the gasification gas to pass therethrough. it and a H _{2 S} and / or tar-sulfur compound removal device having a sulfur compound removal agent layer formed by filling a sulfur compound removal agent to remove COS Te,
A gas purification apparatus, wherein the tar removal agent layer and the sulfur compound removal agent layer in the tar / sulfur compound removal apparatus are of a fixed bed type. An apparatus for purifying gasified gas obtained by thermochemical gasification,
Tar remover / sulfur compound remover formed by mixing and filling a tar remover for removing tar in the gasified gas and a sulfur compound remover for removing H ₂ S and / or COS in the gasified gas The tar removal agent / sulfur compound removal agent mixed layer has a mixing layer, and the tar removal agent / sulfur compound removal agent mixed layer is moved to update the tar removal agent / sulfur compound removal agent mixed layer. A gas purification apparatus characterized by being a layer type. An apparatus for purifying gasified gas obtained by thermochemical gasification,
Tar remover / sulfur compound remover formed by mixing and filling a tar remover for removing tar in the gasified gas and a sulfur compound remover for removing H ₂ S and / or COS in the gasified gas A gas purification apparatus comprising a mixed layer, wherein the tar removing agent / sulfur compound removing agent mixed layer is a fixed bed type. An apparatus for purifying gasified gas obtained by thermochemical gasification,
A moving bed type tar removal that has a tar removal agent layer that is filled with a tar removal agent that passes through the gasification gas and removes the tar and moves the tar removal agent layer to renew the tar removal agent layer. Tar remover / sulfur obtained by mixing and filling a device, a tar remover for removing tar in the gasified gas, and a sulfur compound remover for removing H ₂ S and / or COS in the gasified gas A gas purification apparatus comprising: a tar / sulfur compound removal device having a compound removal agent mixed layer, wherein the tar removal agent / sulfur compound removal agent mixed layer is a fixed bed type. Tar removal agent is activated carbon, gas according to claim 1, specific surface area of the activated carbon, characterized in that 250 meters 2 / ^g or more, and / or average pore diameter of 0.1nm or more Purification equipment.   The gas purification apparatus according to any one of claims 1 to 8, wherein the sulfur compound removing agent is a carbonaceous material.   The gas purification apparatus according to any one of claims 1 to 8, wherein the sulfur compound removing agent is activated carbon. Sulfur compound removal agent is activated carbon, claim and further comprising a temperature control unit in ambient temperature of the sulfur compound removal agent layer to adjust the temperature of the gasification gas to be from 160 to 500 ° C.. 1 to The gas purification apparatus according to any one of 8. The gas purification apparatus according to any one of claims 1 to 8, wherein the sulfur compound removing agent is biomass char, lignite char or iron-supported lignite char . Sulfur compound removal agent biomass char, a brown coal char or supporting iron brown coal char, with a temperature control unit in ambient temperature of the sulfur compound removal agent layer to adjust the temperature of the gasification gas to be 160-500 ° C. The gas purification apparatus according to any one of claims 1 to 8, wherein

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