JP6499882B2 - Continuous fixed bed catalytic reactor and gas reforming method using the same - Google Patents

Description

  The present invention relates to a continuous fixed bed catalytic reactor for performing a gas fluid reforming reaction using a bulk catalyst and a gas reforming technique using the same.

  In a chemical reaction of a fluid using a fixed bed catalyst reactor filled with a catalyst, there is often a problem that a large amount of impurities accumulate in the catalyst layer and hinder the flow of the raw material gas. Contaminants may be derived from dust flying from upstream (that is, dust contained in the raw material gas), but when a product such as a solid is produced by a catalytic reaction, this solid product can be a contaminant. . In particular, when catalytic reforming is performed using coal dry distillation gas or the like as a raw material gas, solid hydrocarbons (coke) generated by decomposition of hydrocarbons in the raw material gas grow in the space between the catalyst particles to form a catalyst layer. May be blocked. The coke particles generated in the catalyst layer in this way are often sized so as not to pass through the neck portion of the space between the catalyst particles (the portion where the gap cross-sectional area between the catalyst particles is minimum). Coke cannot be removed from the catalyst layer by a commonly used method such as backwashing. For this reason, various techniques have been tried to remove coke in the catalyst layer.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2010-77219), hydrogen, carbon dioxide, water vapor, and a tar-containing gas are brought into contact with a catalyst containing nickel, cerium, and aluminum in a fixed bed catalytic reactor. A technique for reforming the contained gas is disclosed. In this technique, it is described that a regeneration treatment is necessary in which water vapor or air is brought into contact with the catalyst in order to remove coke.

  Patent Document 1 also illustrates the use of moving bed type and fluidized bed type catalytic reactors. In these systems, carbon deposited on the catalyst surface can be removed during the reaction operation. However, such a reactor treats high-temperature, high-pressure, and highly corrosive fluids in particular because of the complexity of the equipment and the severe damage and wear of the catalyst compared to the fixed-bed catalyst reactor. As a reactor for this is not common.

  On the other hand, in the fixed bed reactor which does not have the above-mentioned problems in moving bed type and fluidized bed type catalyst reactors, solid precipitates as by-products are deposited as impurities in the catalyst layer during the reaction, and the catalyst A problem often occurs that the reactivity of the catalyst layer is lowered and the ventilation resistance of the catalyst layer is remarkably increased to block the catalyst layer.

  As a means for preventing the clogging of the catalyst layer due to the deposition of solid precipitates during the reaction without performing the regeneration treatment, for example, Patent Document 2 discloses an inflow path for a raw material gas for catalytic reaction and an outflow of reformed gas. A catalyst reaction vessel that is connected to the passage, is connected to the inflow passage and the outflow passage and accommodates the catalyst layer of the bulk catalyst, has a gas permeability that allows passage of fluid, and holds the catalyst layer, and a catalyst holder A continuous fixed bed catalytic reactor having a drive mechanism (elevating device) for elevating and lowering a catalyst layer is disclosed. Here, the catalyst layer is in contact with the inner wall of the reaction vessel. FIG. 1 shows the configuration of a continuous fixed bed catalytic reactor disclosed in Patent Document 2. 1A is a plan view, FIG. 1B is a side sectional view, and FIG. 1C is a BB sectional view of FIG.

JP 2010-77219 A JP 2013-146703 A

  In the apparatus of Patent Document 2, when the generation rate of impurities is relatively low, a majority of the impurities generated in the catalyst layer can be dropped by gravity and removed from the catalyst layer. However, in the case where the generation rate of contaminants in the catalyst layer is particularly large, the generation rate of contaminants exceeds the removal rate of contaminants, and the contaminants remaining in the catalyst layer gradually accumulate in the catalyst layer. There is a case.

  An object of the present invention is to provide a continuous fixed-bed catalyst reactor capable of efficiently removing solid products generated and deposited in a fixed-bed catalyst layer, that is, contaminants, and using this, a raw material gas, particularly tar containing The object is to provide a gas reforming method using a catalyst for reforming a raw material gas with high efficiency.

In order to solve the above-mentioned problems, the following solutions have been invented as a result of the inventor's research.
(1) a raw material gas supply unit for supplying a raw material gas for catalytic reaction;
A catalyst layer is formed by accommodating the bulk catalyst so that the bulk catalyst contacts the inner wall of the container, and the raw material gas is passed through the catalyst layer to reform the raw material gas. A catalytic reaction vessel to be produced;
The source gas inflow path and the reformed gas outflow path;
A catalyst holder which is installed below the inside of the catalyst reaction vessel to hold the catalyst layer, has air permeability and can be raised and lowered;
A continuous fixed bed catalyst reaction device comprising a drive mechanism for raising and lowering the catalyst holder,
Furthermore, a removal gas supply unit that supplies a removal gas for removing impurities in the catalyst layer to the catalyst reaction vessel;
A control unit that supplies the removal gas to the catalyst layer by controlling the removal gas supply unit during the raising and lowering of the catalyst holder by the drive mechanism,
The raw material gas contains coal dry distillation gas containing tar, and the contaminants in the catalyst layer are coke,
The removal gas supply unit can increase the supply flow rate of the removal gas higher than the supply flow rate of the raw material gas when reforming the raw material gas,
And the said removal gas supply part can supply the said removal gas from which the linear velocity in the said catalyst layer becomes 0.4 m / s or more vertically upwards, or 0.2 m / s or more vertically downwards A continuous fixed bed catalytic reactor characterized by the above.

(2) The continuous fixed bed catalytic reactor according to (1) , wherein the removal gas supply unit is configured so that the removal gas flows downward in the catalyst layer.

(3) The removal gas supply unit is configured so that the removal gas flows upward in the catalyst layer, and is configured so that the flow rate of the removal gas can be changed to two or more values. The continuous fixed bed catalytic reactor according to (1) , characterized in that:

(4) the raw material gas supply unit, characterized in that the Ru with the coal carbonization gas generator (1) to a continuous fixed bed catalytic reactor according to any one of (3).

(5) The source gas supply unit also serves as the removal gas supply unit, and is configured so that the source gas can be used as the removal gas, and as the removal gas to the catalytic reaction vessel The continuous fixed-bed catalytic reactor according to any one of (1) to (4) , further comprising a speed increasing portion for the supply flow rate of the raw material gas capable of increasing the supply flow rate of the raw material gas.

(6) A gas reforming method using the apparatus according to any one of (1) to (4),
The raw material gas contains coal dry distillation gas containing tar, and the contaminants in the catalyst layer are coke,
When supplying the removal gas to the catalyst reaction vessel, the supply of the raw material gas is stopped, and the catalyst holder is moved up and down so that the linear velocity in the catalyst layer is vertically upward. A gas reforming method using a continuous fixed bed catalytic reactor, wherein the gas is supplied at 0.4 m / s or more, or 0.2 m / s or more vertically downward .

(7) A gas reforming method using the apparatus according to any one of (1) to (4),
The raw material gas contains coal dry distillation gas containing tar, and the contaminants in the catalyst layer are coke,
0.4m when supplying the stripping gas into the catalytic reaction vessel, said catalyst retainer to lift during supply of the raw material gas, the stripping gas, the linear velocity of said catalyst layer is vertically upward / S or more, or a gas reforming method using a continuous fixed bed catalytic reactor characterized by being fed vertically 0.2 m / s or more .

(8) The gas reforming using the continuous fixed bed catalytic reactor according to (6) or (7) , wherein the removed gas is a non-reactive gas that does not react with the bulk catalyst. Method.

(9) The gas reforming method using the continuous fixed bed catalytic reactor according to (8) , wherein the removal gas is nitrogen gas.

(10) A gas reforming method using the apparatus according to (5),
The raw material gas contains coal dry distillation gas containing tar, and the contaminants in the catalyst layer are coke,
When supplying the removal gas to the catalytic reaction vessel, the supply of the raw material gas is increased by an increase part of the supply flow rate of the raw material gas, and the catalyst holder is moved up and down to supply the raw material gas to the catalyst reaction vessel. A continuous fixed bed catalyst, characterized in that it is supplied as a removal gas so that the linear velocity in the catalyst layer is 0.4 m / s or more vertically upward or 0.2 m / s or more vertically downward. Gas reforming method using a reactor.

Here, the features of the present invention are as follows.
(Feature 1 of the present invention)
(Prior Art 1) About the technique of Patent Document 2 There are cases where impurities in the catalyst layer cannot be sufficiently removed simply by raising and lowering the catalyst layer.
The reason is that, as a result of the inventor's investigation, it has been found that impurities are likely to remain immediately after the lifting operation immediately above the portion where the catalyst holder and the catalyst are in contact (contact portion of the holder). Since this part performs almost the same movement as the cage, the relative movement between the catalysts that promotes the fall and scattering of coke is small, and the contact portion of the cage prevents the fall and scattering of coke. Coke accumulates on the contact area. For these reasons, the technology described in Patent Document 2 may not be able to sufficiently remove impurities.

(Prior art 2) About the technique which ventilates a high-speed air current to a stationary catalyst layer The technique which supplies a high-speed air current to a catalyst layer can also be assumed as a technique of removing a contaminant from a catalyst layer. However, this technique hardly removes impurities in the catalyst layer. The first reason is that coke particles generated between the catalyst particles and growing larger than the space neck portion dimension between the catalyst particles cannot pass through the neck portion by the air flow. The second reason is that a channel that is relatively easy to vent is formed in a part of the catalyst layer, and only impurities along the channel can be removed. In addition, since the flow path formed in this way also becomes a flow path for the raw material gas at the time of reforming, the discharge speed of coke cannot catch up with the coke generation speed in this flow path, and this flow path is eventually closed. After this flow path is closed, the flow path is formed at the next place where it is easy to ventilate, but the air flow resistance in the new flow path is much larger than the air flow resistance in the initial flow path. As a result of repeated formation of a proper flow path, the entire catalyst layer eventually becomes blocked.

(Technology of the present invention)
Only during the raising and lowering of the catalyst layer, a high-speed air flow is passed through the catalyst layer. As a result, it is possible to remove the most of the impurities in the catalyst layer while suppressing the damage and wear of the catalyst as compared with the moving bed and the fluidized bed. Hereinafter, the principle will be described.

  In the prior art 2, the gas flow path is fixed. However, in the present invention, the gas flow path is changed by a relative position change between the catalyst particles by raising and lowering the catalyst layer. For this reason, in this invention, the contaminant along a new flow path can be removed.

  In particular, when the catalyst layer descends, the upper portion of the catalyst layer tends to fall behind the lower portion due to the effect of wall friction, so the filling rate of the catalyst layer temporarily decreases. At this time, since the average gap between the catalysts is enlarged, the airflow reaches a portion where the airflow is difficult to pass (for example, a catalyst or the like immediately above the contact portion of the catalyst holder), and impurities can be removed there. In addition, since the generation | occurrence | production speed | velocity | rate of coke is originally low in the site | part to which an airflow (raw material gas) does not reach | attain, it may be thought that it is not necessary to aim at coke removal in this site | part. However, in practice, contaminants are gradually generated through diffusion of the raw material gas even in a region where the airflow is difficult to reach, and the contaminants generated here overflow from this region and reach a region where the adjacent airflow is easily ventilated. Therefore, since the ventilation resistance is increased at the site where the airflow is easily ventilated, there is a need to remove impurities even at the site where the airflow is difficult to reach.

  The region directly above the contact portion of the cage is inherently (when stationary) also a region that is difficult to vent. If the catalyst layer is moving up and down, it is easy to ventilate the high-speed airflow here, so that the coke deposited between the catalysts immediately above the cage can be removed by venting.

(Regarding the difficulty of combining conventional techniques 1 + 2)
Since a relatively large load is applied to the catalyst when raising or lowering the catalyst, there is a possibility that the catalyst strength may be adversely affected. Therefore, raising and lowering of the catalyst should be performed intermittently for a short time. For this reason, the catalyst layer is stationary without moving up and down during most of the operation. When a high-speed air flow is generated without raising or lowering the catalyst layer, various problems arise. Hereinafter, problems will be described for each method for generating a high-speed airflow.
(1) Method for obtaining a high-speed air flow by increasing the flow rate of the source gas Even if the amount of catalyst is the same, the space velocity (SV) of the source gas increases by increasing the flow rate of the source gas. For this reason, the consumption rate (selectivity) of source gas falls. Therefore, there is a problem in reaction characteristics. Further, when the flow rate of the source gas is increased, the flow rate of the source gas is increased. Therefore, even if the amount of impurities in the catalyst layer is the same, the ventilation resistance increases, and the allowable upper limit of the ventilation resistance is reached earlier during operation.

  When a high-speed air current is forcibly supplied to the catalyst layer having a large ventilation resistance, a high pressure difference is generated between the upstream and downstream of the catalyst layer. When the airflow resistance is suddenly reduced due to the scattering of some impurities, the high air pressure explosively increases the air flow velocity, which may cause the catalyst to scatter (in the case of upward flow).

(2) Method for obtaining a high-speed air flow by reducing the cross section of the reaction vessel When the cross section of the reaction vessel is reduced, the flow rate of the raw material gas is increased. Therefore, even if the amount of impurities in the catalyst layer is the same, the ventilation resistance increases, and the allowable upper limit of the ventilation resistance is reached earlier during operation.

(3) A method of obtaining a high-speed air flow by mixing a non-reactive gas or the like into the raw material gas has the same problem as (1).

  (4) In the first place, it has not been known to those skilled in the art that if a high-speed air flow is supplied to the catalyst layer while the catalyst layer is moved up and down, a dramatic effect can be obtained in removing impurities. It has been known that the airflow flows around all the particles in the case where the gap between the particles is extremely large as in the case of the airflow conveying technique (the case where the particles hardly contact each other). However, in the catalyst layer ascending / descending technology in which the relative position between the catalyst particles changes only slightly, it has not been known at all that this slight change in relative position has a great influence on the air flow around the contaminant and can remove the contaminant. .

  In fact, applying a low linear velocity (LV) air flow corresponding to an SV suitable for reforming in a standard size catalytic reaction vessel during raising and lowering the cage hardly affects the contaminant removal performance. In the present invention, it has been found that the contaminant removal performance can be remarkably improved if the LV applied during raising and lowering of the cage exceeds a critical value. This critical value is smaller than that in the case where impurities are removed only by high-speed air flow without moving up and down the catalyst layer. The linear velocity (LV [m / s]) in the present invention is defined as the gas flow rate (not including the reaction product gas) input to the catalyst layer per cross-sectional area of the catalyst layer. Further, when the cross-sectional area of the catalyst layer changes in the gas traveling direction, the cross-sectional area at the catalyst layer inlet is calculated. Further, the cylinder velocity (SV [1 / h]) of the reaction gas is defined as the raw material gas flow rate (not including the reaction product gas) per catalyst layer volume (reactor volume). Furthermore, both LV and SV are defined as values converted to gas standard states.

  On the other hand, if an attempt is made to supply a high-speed air stream without raising or lowering the already-occluded packed bed (catalyst layer in the present invention), since most of the contaminants are not removed at the initial stage of the air flow supply, the upstream-downstream area It was necessary to give an extremely large pressure difference. For this reason, a high-temperature apparatus causes a problem in strength, and once a certain amount of impurities is removed, the ventilation resistance rapidly decreases, and this large pressure difference explosively increases the air flow velocity and scatters to the catalyst. Caused problems. For this reason, it has been considered that a method of removing impurities by supplying a high-speed air flow to the packed bed is not preferable. For the above reasons, it has not been assumed at all to supply a high-speed air flow to the catalyst layer that is moving up and down.

  However, in the present invention, the closed catalyst layer is moved up and down to create a state of low ventilation resistance, and a high-speed air flow is supplied thereto. This eliminates the need for a high pressure difference to remove contaminants. Therefore, the above problem does not occur.

(About this time's knowledge about the influence of the air flow while moving up and down)
A cold test described below has revealed that most of the impurities in the catalyst layer can be removed by applying a high-speed air flow during ascending and descending (FIG. 2).

  On the other hand, even if a high-speed air flow similar to that shown in FIG.

(About device in the present invention)
By controlling the air flow so that a high-speed air flow is supplied only during the ascending / descending operation in conjunction with the ascending / descending of the catalyst layer, it is possible to improve the removability of contaminants and to process the raw material gas under suitable SV conditions when it is not elevated it can.

(Feature 2 of the present invention)
In the conventional reactor technology for processing a raw material gas (eg, coke oven gas) containing a large amount of dust in the raw material gas described in Patent Document 2 and the like, large dust flying from the upstream is not mixed in the catalyst layer. The raw material gas was vented upward with respect to the catalyst layer, and large dust was dropped before flowing into the catalyst layer.

  As a result of the investigation by the present inventors, when removing gas is supplied upward when blowing away foreign substances (by-products + dust) in the catalyst layer, specific dimensions that balance the ascending force of the removing gas and the gravity of the foreign substances themselves It was found that the contaminant particles remained in the catalyst layer.

  In order to avoid this, this specific dimension is changed by supplying the removal gas under two or more flow rate conditions during raising and lowering of the catalyst layer. In other words, even if contaminant particles of a specific size that balance the ascending force and gravity remain in the catalyst layer at a certain flow rate condition, the contaminant particles remain at the ascending force at other flow rate conditions that are changed while the catalyst layer is raised or lowered. Either gravity or gravity works preferentially to move through the catalyst layer and can be discharged from the catalyst layer.

  That is, in the movement of the contaminants in the upward flow, the contaminants are scattered above the catalyst layer if the ascending force is superior, but the contaminants fall below the catalyst layer if the gravity is superior.

(Feature 3 of the present invention)
By supplying the removal gas downward, all of the forces acting on the particles are lowered, so there is no particular size of contaminants remaining in the catalyst layer due to the balance between the above-mentioned ascending force and gravity, Contaminants can be suitably removed by the dimensions.

(Feature 4 of the present invention)
By using a non-reactive gas as the removal gas, the removal gas flow rate can be freely set regardless of the generation rate of the raw material gas. For example, when the raw material gas is a coke oven gas, since the raw material gas generation rate depends on the coal decomposition rate, it is not easy to change the generation rate rapidly.

(Feature 5 of the present invention)
Even if the removal gas is supplied at a flow rate corresponding to the above critical LV, the workability can be improved by increasing the removal gas flow rate higher than the raw material gas flow rate during reforming. For example, in FIG. 2, under the condition of LV = 0.2 m / s (that is, the critical LV condition of less than 0.4 m / s), the condition corresponding to the raw material flow rate at the time of reforming with respect to the coke removal performance ( LV = 0.1 m / s). However, under the condition of LV = 0.2 m / s, it was possible to remove about 2 mass% of the packed coke mainly from fine particles having a diameter of about several tens of μm upward from the catalyst layer. Such fine particles are liable to enter a narrow gap between the catalyst holder and the inner wall of the reaction vessel, and may hinder the catalyst layer from being raised or lowered. Therefore, it is preferable to remove the fine particles from the catalyst layer. That is, when LV = 0.2 m / s, it can be said that fine particles that may hinder the raising and lowering of the catalyst layer can be efficiently removed. Since the condition of LV = 0.2 m / s is not a preferable SV condition at the time of reforming, it is necessary to use the present invention.

  According to the catalytic reaction apparatus of the present invention, impurities can be efficiently removed by moving the entire catalyst layer up and down and supplying a removal gas to the catalyst layer.

It is a schematic diagram of a prior art. It is a figure which shows the relationship between the linear velocity of removal gas, and a contaminant (coke) removal rate. It is a schematic diagram which shows an example of the whole structure of this invention. It is a schematic diagram which shows an example of the structure around the catalyst reactor of this invention. It is a schematic diagram which shows an example of the structure around the catalyst reactor of this invention. It is a schematic diagram which shows an example of the structure around the catalyst reactor of this invention. It is a schematic diagram which shows an example of the whole structure of this invention. It is a schematic diagram which shows an example of the catalyst reactor periphery of this invention. It is a schematic diagram which shows an example of the catalyst reactor periphery of this invention. It is a schematic diagram which shows an example of the whole structure of this invention. It is a graph which shows an example of the time transition of coke removal in the present invention.

[First Embodiment]
(overall structure)
FIG. 3 shows the overall configuration of the continuous fixed bed catalytic reactor according to the first embodiment.

(Structure around the reactor)
The structure around the reactor is shown in FIG.
As the catalytic reactor, the catalytic reactor described in Patent Document 2, for example, the catalytic reactor shown in FIG. 1 can be used. In FIG. 4, the catalyst reaction vessel, the catalyst layer, the catalyst holder, the elevating mechanism, the driving device and the like are basically the same as those in FIG. 3 and 4, a removal gas supply pipe, a removal gas cutoff valve / flow rate adjustment valve (supplying a removal gas), a raw material gas cutoff valve, a control device, and the like are further added to the configuration described in Patent Document 2. ing. Of the continuous fixed bed catalytic reactor, the configuration described in Patent Document 2 has the function described in Patent Document 2. Therefore, here, a configuration newly added to the configuration described in Patent Document 2 will be described.

(Raw gas supply unit)
The raw material gas supply unit supplies the raw material gas to the catalytic reactor. The source gas supply unit is, for example, a gas holder or a gas generation furnace (coke furnace or the like). Here, the coke oven is an example of a coal dry distillation gas generator.

(Removal gas supply unit)
The removal gas supply unit supplies the removal gas to the catalytic reactor. The removal gas supply unit is, for example, a gas holder or a gas cylinder.

(Raw gas shutoff valve)
The raw material gas cutoff valve is a valve capable of shutting off the supply of the raw material gas to the catalytic reactor. The raw material gas cutoff valve may be kept at a high temperature so as not to cool the raw material gas, and when the raw material gas is a tar-containing gas, so as not to condense the tar in the raw material gas. For example, when the shutoff valve is heated to the reaction temperature of the raw material gas (eg, 800 ° C.), for example, a high temperature furnace gas gate valve disclosed in Japanese Patent Application Laid-Open No. 2011-099559 is used as the raw material gas shutoff valve. be able to.

(Removal gas shutoff valve, removal gas flow rate adjustment valve)
The removal gas shut-off valve is a valve that can shut off the supply of the removal gas to the catalytic reactor. The removal gas flow rate adjustment valve is a valve capable of adjusting the supply amount of the removal gas to the catalytic reactor. The removal gas cutoff valve and the removal gas flow rate adjustment valve are not particularly limited, and may be a commercially available electric valve, air cylinder valve, or the like.

(Blower)
The blower supplies (blows) the reformed gas cooled by the cooling device to the gas holder. The blower is not particularly limited, and may be a commercially available turbo or positive displacement blower.

(Dust collector)
The dust collector is a device for removing and collecting dust in the reformed gas and the removed gas. The collected dust (for example, coke) can be reused for fuel or the like. When a scrubber is used as the cooling device, the scrubber can also be used for dust collection, and an independent dust collector can be omitted. Specific examples of the dust collector include a cyclone, an impactor, and a bag filter.

(Cooling system)
The cooling device is a device for removing condensed components (such as tar) in the reformed gas and cooling the reformed gas to a temperature (eg, less than 80 ° C.) that can be supplied to a commercially available blower or gas holder. Specific examples of the cooling device include a heat exchanger and a scrubber.

(Speed increase part)
The speed increasing unit is a device for maintaining the supply flow rate of the removal gas at a predetermined value (predetermined range) larger than the raw material gas flow rate during reforming. In the configuration of the present embodiment, the speed increasing part can be used also by giving a sufficiently large gas supply capability to the removed gas supply part. The speed increasing unit may have a configuration different from that of the removal gas supply unit. In this case, the speed increasing part may be a blower, for example.

(Control device)
The control device switches the source gas cutoff valve, the removal gas cutoff valve, and the removal gas flow rate adjustment valve according to the procedure of the operation method described later, and executes a sequence for adjusting the operation state of the blower as necessary It is. Specific examples of the control device include a sequencer and a general purpose computer. In addition, all the raw material gas cutoff valves etc. may be operated manually, and a control apparatus may be abbreviate | omitted in this case.

(Raw material gas)
The source gas is not particularly limited as long as it is reformed by the catalyst when passing through the catalyst layer. For example, the source gas may be a gas containing hydrocarbons, a gas containing tar together with hydrocarbons, or the like. When the raw material gas is a gas containing tar, coke produced as a by-product during the reforming of the raw material gas is likely to be deposited in the catalyst layer as a contaminant. Therefore, when the source gas is a gas containing tar, the effect of the present embodiment is likely to appear remarkably. Examples of the gas containing hydrocarbon include natural gas, LPG, naphtha and the like. Examples of the gas containing tar together with hydrocarbons include coke oven gas (coal dry distillation gas) and biomass dry distillation gas. The source gas is heated to the vicinity of the reaction temperature (reforming temperature) (eg, 800 ° C.) using a heating unit (not shown) or the like, and then supplied to the catalyst layer. The heating unit heats the source gas in the heating section.

(Removed gas)
The removal gas is a gas for removing impurities from the catalyst layer. The removal gas may be any gas as long as it does not react with the catalyst and does not cause a phase change under the reaction temperature and pressure conditions when the raw material gas is reformed. As the removal gas, for example, nitrogen gas, argon gas, refined coke oven gas (coke oven gas from which tar and moisture have been removed) and the like can be used. Moreover, since the removal gas is supplied to the catalytic reactor in a short time, even if the removal gas is at room temperature, the cooling of the reactor by the removal gas is limited. For this reason, the removal gas may be supplied at room temperature.

(Catalyst cage lifting stroke)
In order to sufficiently perform the relative movement between the catalysts, it is preferable that the raising / lowering stroke of the cage is large. For example, the effect of removing coke is present even with a lifting stroke of about 0.1 times the representative size of catalyst particles (eg, catalyst particle diameter). Therefore, even with such an up / down stroke, a certain degree of removal of impurities such as solid hydrocarbons (coke) on the catalyst surface can be obtained. However, in order to obtain a sufficient contaminant removal effect, the lifting / lowering stroke of the cage 12 is preferably 0.5 times or more, more preferably 1 or more times the representative size of the catalyst particles.

  On the other hand, when the lift stroke is extremely large, the reaction vessel and the drive mechanism are increased in size, which is not efficient. Moreover, the effect similar to a bigger raising / lowering stroke is acquired by repeatedly raising / lowering a small stroke (however, 1 times or more). Therefore, the lifting stroke is preferably 10 times or less of the representative dimension of the catalyst particles.

(Catalyst cage lifting speed)
The required ascending force required to raise the catalyst layer together with the cage is smaller as the ascent rate is smaller. As a result of the investigation by the present inventors, it has been found that the required ascending force when raising the catalyst layer together with the cage at 10 mm / s needs to be double that when raising at 1 mm / s. Further, at a high rising speed, the catalyst is easily destroyed. Therefore, it is preferable that the rising speed is small. However, the difference in required ascending force between the case of raising at 1 mm / s and the case of raising at 0.5 mm / s is small, so it is not always necessary to make it slower than 1 mm / s. Further, even if the rising speed is 10 mm / s, it may be applied as long as the catalyst is not destroyed. Usually, it may be raised at about 1 to 10 mm / s.

  On the other hand, as described above, the descending speed of the cage is preferably large. In particular, if the cage is lowered at a speed (for example, 100 mm / s) larger than the free fall speed of the catalyst at the lowermost end, the catalyst is detached from the cage and the restriction between the catalysts is reduced, and the relative relationship between the catalysts is reduced. It is preferable because a large amount of exercise can be taken. However, there is no difference in the effect obtained even if the cage is lowered at a speed extremely higher than the free fall speed of the catalyst. Also, if the lift stroke is large, care should be taken because if the catalyst is lowered at a speed significantly higher than the free fall speed of the catalyst, the catalyst may be cracked or pulverized due to the drop impact. . Usually, it may be lowered at about 1000 mm / s or less. Further, the lowering speed of the cage does not necessarily need to be higher than the free fall speed. This is because the catalyst in the catalyst reaction vessel is strongly bound by the inner wall of the catalyst vessel, so even if the lower end constraint (holding) is removed, the catalyst falls on average at a lower speed than the free fall speed and between the catalysts. This is because a drop speed difference (relative motion between the catalysts) is generated, so that the effect of removing impurities in the catalyst layer can be obtained to a certain degree even if the descending speed of the cage is less than the free falling speed. From this viewpoint, the descending speed of the cage may be about 10 mm / s or more.

(Catalyst type)
Any catalyst that can reform the source gas (for example, steam reforming or cracking) can be used. As the catalyst, for example, when the raw material gas is a coke oven gas containing tar, a Ni-alumina catalyst, a Ni-magnesia-alumina catalyst, or the like can be used.

(Catalyst size)
In general, a catalyst configured by supporting a substance having a catalytic action on a porous simple substance needs to remain in a catalyst layer located on a cage. Therefore, the catalyst needs to have a size that does not pass through the opening of the cage.

  Further, in order to leave the catalyst on the cage and pass the cage through the powdered coke and remove it from the catalyst layer, the catalyst is usually a powdered coke having a size of several tens to several hundreds of μm. Need to be larger, i.e. agglomerated. From such a viewpoint, it is preferable that the representative dimensions, for example, the diameter, of the bulk catalyst are 1 mm or more and 100 mm or less.

(Catalyst shape)
As described above, when a catalyst is held by a specific cage, a minimum value exists in the smallest representative dimension of the same catalyst outer surface. When the volume of the catalyst layer is constant, generally, the greater the number of catalysts, the greater the total surface area of the catalyst, and the reaction rate of the reaction vessel 11 can be improved. Therefore, a sphere or a catalyst having a shape close to a sphere is preferable because the number of catalysts can be easily increased in a certain volume. Even if the volume surrounded by the outer periphery of the catalyst is the same, a shape having a larger surface area, for example, a cylindrical shape or a ring shape is also preferable.

(Catalyst layer height)
The aspect ratio is preferably 2.5 or less. It is preferable that the height of the catalyst is three or more layers (the maximum height in which three catalysts are stacked in the vertical direction), that is, three times or more of the catalyst representative dimension (diameter, etc.). Here, the aspect ratio is a value obtained by dividing the height / of the catalyst layer by the thickness (or diameter).

(Timing for removing impurities)
The operation for removing impurities may be appropriately performed between reforming of the raw material gas. For example, it may be performed at regular time intervals such as every hour. Alternatively, the removal operation may be performed at a stage where the ventilation resistance of the catalyst layer becomes a predetermined value or more according to the accumulation state of the contaminants in the catalyst layer.

  It is preferable that the removal gas supply time is a time period including the period from the start of raising / lowering of the cage to the completion of raising / lowering. However, when a high-speed air current is ventilated through a catalyst layer having extremely large ventilation resistance, such as a blocked catalyst layer, a high pressure difference may occur. For this reason, supply of the removal gas should be started after the removal of contaminants by raising and lowering the catalyst layer, or the flow velocity of the removal gas should be gradually increased in accordance with the progress of removal of the impurities by raising and lowering the catalyst layer. Is more preferable. Contaminants in the catalyst layer are removed from the catalyst layer by being dropped or scattered upward or downward by the removal operation. Contaminants (for example, coke particles) adhering to or depositing on the catalyst surface are separated from the catalyst surface by the removal gas, and the separated impurities are conveyed to the outside of the catalyst layer by the removal gas. Therefore, the removal gas promotes the removal of coke.

(how to drive)
Hereinafter, the operation method of the continuous fixed bed catalytic reactor, specifically, the raw material gas and removal gas valves and the gas flow state will be described.
(1) During reforming operation Raw material gas shutoff valve: Open Removed gas shutoff valve: Closed Removed gas flow control: No matter Raw material gas flow (specifically, flow rate; the same applies hereinafter): SV conditions suitable for reaction (in catalyst layer) (Upward flow, details will be described later)
Removed gas flow: 0

(2) During catalyst layer ascending / descending Source gas shutoff valve: Closed Removed gas shutoff valve: Open Removed gas flow control valve: Predetermined opening (set so that the removed gas flow described later is realized)
Here, the shut-off valves may be opened and closed simultaneously or with a time difference.
Raw material gas flow: 0
Removal gas flow: It is preferable that the flow rate larger than the raw material gas flow rate in (1) and the upward flow linear velocity (LV) in the catalyst layer be 0.4 m / s or more.

  When LV is less than 0.4 m / s, the effect of removing impurities due to the airflow of the removal gas is not significant. In the case of LV of 0.4 m / s or more, the contaminant removal effect is improved. The upper limit of LV does not exist in principle, and may be determined appropriately in engineering. When the LV is extremely large, the bulk catalyst is fluidized or scattered. When the catalyst strength is relatively low, there is a problem with the catalyst strength, so the maximum flow velocity at which no catalyst scatters becomes the LV upper limit value. On the other hand, when a tough catalyst is used, there is no problem if an anti-scattering measure such as a net is applied above the catalyst layer even if the LV is larger than this.

(3) Moving up and down the catalyst layer (can be implemented as an option after the operation in (2))
Source gas shutoff valve: Closed Removed gas shutoff valve: Open Removed gas flow control valve: Predetermined opening (set to achieve the later-described removed gas flow)
Raw material gas flow: 0
Removal gas flow: LV smaller than raw material gas flow rate in (2), upward flow in catalyst layer LV is preferably about 50 to 70% with respect to LV in (2).
This makes it possible to remove the coke particles having a specific size that cannot be removed from the catalyst layer due to the balance between the ascending force and gravity in (2).

(Source gas space velocity (SV) conditions during reforming)
The SV during reforming is preferably about 100 (1 / h) or more and 1000 (1 / h) or less.
SV = [Raw material gas flow rate] / [Catalyst volume]
Note that SV is defined in terms of a standard value of gas.

[Second Embodiment]
(Reactor peripheral structure)
The structure around the reactor is shown in FIG.
The difference from the first embodiment (FIG. 4) is that the inflow pipe and the outflow pipe of the reactor are turned upside down. As a result, the source gas and the removal gas flow downward in the catalyst layer. The rest is the same as in the first embodiment.

(how to drive)
(1) During reforming operation Material gas shut-off valve: Open Removal gas shut-off valve: Closed Remove gas flow control: No matter Raw material gas flow: SV condition suitable for reaction (downward flow in catalyst layer)
Removed gas flow: 0

(2) During catalyst layer ascending / descending Source gas shutoff valve: Closed Removed gas shutoff valve: Open Removed gas flow control valve: Predetermined opening (set so that the removed gas flow described later is realized)
Raw material gas flow: 0
Removal gas flow: Flow rate larger than the raw material gas flow rate in (1), the absolute value of the downward flow linear velocity (LV) in the catalyst layer is preferably 0.2 m / s or more, more preferably 0.4 m / s or more .

  When the absolute value of LV is less than 0.2 m / s, the effect of removing impurities by the airflow is not significant. In the absolute value of LV of 0.2 m / s or more, the larger the absolute value of LV, the higher the effect of removing impurities. The upper limit of the absolute value of LV does not exist in principle. When the cage strength is relatively low, a cage strength problem occurs. Therefore, the maximum flow rate that does not break the cage is the upper limit of the absolute value of LV, and there is an upper limit when using a strong cage. However, it may be determined appropriately from an engineering point of view.

  Unlike the first embodiment, there are no coke particles that cannot be removed from the catalyst layer by balancing the ascending force and gravity, and therefore it is not always necessary to change the removal gas flow rate during the catalyst ascent and descent.

[Third Embodiment]
(Reactor peripheral structure)
The structure around the reactor is shown in FIG. The source gas supply mode is the same as in the second embodiment, and the removal gas supply mode is the same as in the first embodiment. This is an example in which the supply direction of the source gas and the supply direction of the removal gas are not necessarily matched, and such a form may be adopted if there is an engineering convenience. Other than this (for example, the preferable linear velocity of the removal gas) is the same as that of the first embodiment.

[Fourth Embodiment]
(Removed gas)
In this embodiment, the source gas is used as the removal gas.

(overall structure)
The overall configuration is shown in FIG.

(Reactor peripheral structure)
The reactor peripheral structure may be, for example, any one of the first and second embodiments. However, since supply of the removal gas is unnecessary, for example, as shown in FIGS. 8 and 9, the removal gas-related device may be omitted.

(Raw gas supply unit)
The source gas supply unit may be the same as that in the first embodiment. For example, the raw material gas supply unit is a gas holder or a gas generation furnace (coke furnace or the like).

(Raw gas shutoff valve)
The raw material gas shut-off valve may be a high-temperature valve as in the first embodiment, but there is no need to place the shut-off valve in the high-temperature portion because there is no non-reactive removal gas. For example, as shown in FIG. 7, an inexpensive shut-off valve for room temperature can be used by disposing a shut-off valve downstream of the cooling device.

(Bypass configuration)
In the fourth embodiment, the bypass pipe and the bypass valve are provided in parallel with the blower. The bypass pipe and the bypass valve adjust the flow rate of the gas flowing into the blower.

(how to drive)
(1) During reforming operation Material gas shut-off valve: Open Bypass valve: Closed Blower: Operated at a predetermined speed Raw material gas flow: SV conditions suitable for reaction (The direction of flow in the catalyst layer depends on the selected structure)

(2) Immediately before raising or lowering the catalyst Material gas shutoff valve: Closed Bypass valve: Open Blower: Operate at the same rotation speed as (1) Raw material gas flow: 0 → From the material shutoff valve The pressure in the system rises upstream.
The blower performs a bypass operation and prepares for ventilation in (3).

(3) Catalyst layer is moving up and down Raw material gas shutoff valve: Open Bypass valve: Closed Blower: Operated at the same rotation speed as (1) Removed gas (raw material gas) flow: Since the upstream piping was pressurized until just before, the raw material gas Along with the opening of the shutoff valve, a large differential pressure with the downstream side generates a flow rate larger than the raw material gas flow rate in (1), and acts as a high-speed removal gas. When the reactor of FIG. 9 is used, the linear velocity (LV) of the raw material gas is preferably 0.2 m / s or more, and more preferably 0.4 m / s or more.

  Although the raw material gas is reformed during the raising and lowering of the catalyst, the selectivity of hydrocarbons in the raw material gas is generally lower than that in (1) because of the large SV. However, since the time required for the lifting operation is short and the amount of reformed gas to be generated is relatively small, it is a big problem even if such reformed gas is mixed with the reformed gas in (1) and stored in the gas holder. There is no. In the present embodiment, the source gas can be passed through the catalyst layer while raising and lowering the catalyst layer (that is, while reducing the ventilation resistance of the catalyst layer). Therefore, impurities can be removed at a lower flow rate than when the catalyst layer is not moved up and down. That is, it is possible to suppress a decrease in selectivity when the source gas is used as the removal gas.

(Speed increase part)
When the configuration of the source gas generator, source gas shut-off valve, blower, etc. is operated by the method described in “Operation method” (2) and (3), the flow rate of the removed gas (the source gas being moved up and down) is reformed. Can be increased. That is, in this example, the bypass pipe and the bypass valve function as a speed increasing portion.

  Alternatively, if the blower capacity and the capacity of the raw material gas generating furnace are sufficient, the flow rate of the raw material gas (removed gas) may be increased by simply increasing the rotational speed of the blower during the raising and lowering of the catalyst layer. When such an operation is performed, a necessary large flow rate is generated by gradually decreasing the pressure of the source gas generating furnace (by reducing the amount of source gas accumulated in the furnace). In this case, the blower functions as a speed increasing portion.

  Alternatively, as shown in FIG. 10, a pressure vessel is provided on the outlet side of the cooling device, the inside of the pressure vessel is evacuated in advance during reforming, and when the cage is raised and lowered, the pressure vessel valve is opened to remove the gas (catalyst layer raising and lowering). The removal gas flow rate may be increased by sucking the raw material gas) into the pressure vessel. As a method of reducing the pressure vessel during reforming, the inside of the pressure vessel may be reduced using a vacuum pump with the pressure vessel valve closed. Commercially available pressure vessels and vacuum pumps can be used. In this case, the pressure vessel valve, the pressure vessel, and the vacuum pump function as a speed increasing unit.

  Except for the above configuration, it may be the same as in the first or second embodiment (depending on the selected reactor type).

[Example 1]
In order to verify the effect of the present invention on the impurities in the catalyst layer, a cold test was performed in which a simulated gas imitating the raw material gas was supplied cold into a catalyst reactor containing the impurities.

(Cold test conditions)
(Simulated gas)
Air at normal temperature and pressure was used.

(apparatus)
In the case of upward flow, the apparatus of FIG. 4 was used, and in the case of downward flow, the apparatus of FIG. 5 was used.
However, the removed gas supply unit and the flow rate adjustment valve are omitted. The simulated gas acts as a removal gas.

  Simulation gas flow rate adjustment: The removal gas flow rate during raising and lowering of the catalyst layer was maintained at a predetermined value by adjusting the blower rotational speed control by VVVF using the indicated value of the flow rate (flow velocity) meter.

(Catalyst layer)
An actual catalyst (φ15 mm, Ni-alumina catalyst) was used.
Aspect ratio: 1.2 (value at each stage)
Number of catalyst layers: 2 in the vertical direction Catalyst amount: 3 kg / stage

(Contamination)
Coke (solid hydrocarbon) powder generated in the coke oven gas reforming test was recovered and used. A total of 150 g / stage (filled coke mass) was mixed with the catalyst in advance and supplied to the catalyst layer.

(Elevator)
15 mm stroke, 100 reciprocations in each test Lifting speed: 5 mm / s (when rising), 15 mm / s (when descending), reciprocating operation cycle: 30 s

(Method of measuring the amount of coke splashed)
An electronic balance was placed below the catalyst layer in the reaction vessel, and the falling mass of coke was measured in real time.

  Furthermore, a cyclone was provided on the outlet side of the outflow pipe, and this was periodically decomposed during the cold test to collect the stored coke, and the mass of the coke was weighed to calculate a time-series coke scattering amount. After completion of the test, the reaction vessel was disassembled and the catalyst was recovered together with the coke remaining in the catalyst. This was sieved to separate the coke, and then weighed to measure the residual coke mass.

(Removed gas (simulated gas) flow rate)
LV: Cold tests were conducted under the conditions of -0.4, -0.2, -0.1, 0.1, 0.2, and 0.4 m / s. (A negative sign indicates a downward flow and a positive sign indicates an upward flow). For comparison, a cold test was also performed under conditions of a flow rate of 0 (equivalent to Patent Document 2). In addition, the absolute value of LV of the raw material gas at the time of coal dry distillation gas reforming is about 0.1 m / s or less in the catalyst layer.

(Test results)
The test results are shown in FIG. The coke removal rate is defined by the following equation.
Coke removal rate = 1- (residual coke mass / filled coke mass)

  The coke removal rate is higher than that of the conventional technique (LV = 0) under the condition that the absolute value of LV is 0.4 m / s or more in the upward flow and under the condition that the absolute value of LV is 0.2 m / s or more in the downward flow. Improved. In particular, the maximum removal rate was obtained under the condition of downward 0.4 m / s.

  The condition of LV = 0 corresponds to the prior art (comparative example), and the LV of 0.4 m / s or more or −0.2 m / s or less corresponds to the preferable LV condition (example) in the present invention. Since the LV determined from the preferred SV conditions during coal dry distillation gas reforming is generally in the range of −0.1 m / s to 0.1 m / s, the raising / lowering of the cage without particularly increasing the feed gas. However, the contaminant removal performance is not particularly improved as compared with the LV = 0 condition. On the other hand, it was found that if the conditions of LV of 0.4 m / s or more or −0.2 m / s or less, which cannot be achieved at the time of reforming, are generated when raising and lowering the cage, the contaminant removal performance is greatly improved. .

  When LV = 0.2 m / s, the coke removal rate was lower than the coke removal rate when LV = −0.1 m / s to 0.1 m / s. However, the cyclone was able to recover about 2% by mass of the filled coke mass. Further, when the diameters of these cokes were measured, most of the cokes were particles having a diameter of less than 50 μm. The diameter of the coke was classified by sieving. Therefore, under the condition of LV = 0.2 m / s, about 2% by mass of the packed coke mainly composed of fine particles having a diameter of less than 50 μm was scattered and removed from the catalyst layer. Such fine particles are liable to enter a narrow gap between the catalyst holder and the inner wall of the reaction vessel, and may hinder the catalyst layer from being raised or lowered. Therefore, it is preferable to remove the fine particles from the catalyst layer. That is, when LV = 0.2 m / s, it can be said that fine particles that may hinder the raising and lowering of the catalyst layer can be efficiently removed. Since the condition of LV = 0.2 m / s is not a preferable SV condition at the time of reforming, it can be said that the present invention needs to be used.

  Further, as shown in the time transition of the coke (contaminant) removal rate in the present invention in FIG. 11, in the present invention, the maximum removal effect is obtained at the initial stage of the removal operation (period until the fifth round after the start of the round trip). In addition, it was found that the removal effect persists even in the final stage (the 91st to 100th reciprocating periods). In addition, the coke removal rate in FIG. 11 is a ratio with respect to the filling coke mass of the scattering coke mass (the mass of the coke measured by the electronic balance + the mass of the coke recovered by the cyclone) measured by the coke scattering amount measuring method. Calculated.

[Comparative Example 1]
(Test conditions)
(Equipment / Catalyst layer / Coke)
Same as Example 1. However, in the steps (1) and (3) described later, the catalyst layer is not raised or lowered.

(Removed gas (simulated gas) flow rate)
LV = −0.4 m / s

(Test procedure)
(1) Ventilate for 10 minutes after setting up the catalytic reactor, weigh the fallen coke that is being vented with an electronic balance, disassemble the cyclone after aeration is complete, collect and weigh the coke that flows downstream, and scatter from the total of both The coke mass and coke scattering rate (= scattered coke mass / treatment (aeration) time) were calculated. This operation is referred to as “initial”.

(2) A cold test involving raising and lowering of the catalyst layer similar to the LV = 0 m / s condition in Example 1 (corresponding to the technique of Patent Document 2) is performed (100 reciprocations), the scattered coke is collected, and the electronic balance The weighed value was recorded at This operation is for previously removing coke that easily falls in the catalyst layer by raising and lowering the catalyst.

(3) After completion of the cold test, the same test as in (1) was performed again, and the scattered coke mass (recovered amount from the cyclone + (2) increment of the electronic balance measurement value after the flow rate) was calculated. This operation is referred to as “after initial”. The operations of (1) (= “initial”) and (3) (= “after initial”) are the main parts of this comparative example.

(Test results (Table 1))
Table 1 shows a comparison of the coke scattering speed in this comparative example with the test result in the LV = −0.4 m / s condition (corresponding to the present invention) in Example 1. Here, the “initial stage” in the present invention is the period from the start of lifting to the fifth round, and the “end stage” is the period from the 91st to the 100th. When high-speed airflow is supplied to the stationary catalyst layer, the effect of removing contaminants close to the present invention is obtained in the initial stage, but the coke that easily falls in the catalyst layer has already been removed. About 30% of the coke still remained in the catalyst layer (the coke residual rate is the coke removal rate under the condition of LV = 0 m / s in Example 1 (FIG. 2) (1.0). Despite this, the contaminants could hardly be removed. That is, even if a high-speed air flow is passed through the catalyst layer in this comparative example, it is considered that the coke removal rate rapidly decreases after the coke that is easily removed is scattered in the initial stage. On the other hand, at the end of the present invention, although the coke that easily falls in the catalyst layer has already been removed as in the end of the LV = 0 m / s condition in Example 1, the catalyst layer The coke can be continuously scattered by moving up and down. In addition, the operation is sequentially performed such that the operation of applying the high-speed airflow (“after the initial stage” in the present comparative example) is performed after the raising / lowering operation of the catalyst layer (LV = 0 m / s condition in Example 1). It was found that a sufficient coke removal effect could not be obtained even after separation. That is, the high-speed air flow application operation can improve the coke removal effect only when it is performed simultaneously with the catalyst lifting operation as in the present invention.

  On the other hand, as shown in FIG. 11, in the present invention, the contaminant removal effect was maintained even during the “after initial period”. In other words, it was found that the removal of impurities according to this comparative example, which is simply the application of a high-speed air flow, has a significantly shorter effect time than the present invention.

[Comparative Example 2]
(Test conditions)
(Equipment / Catalyst layer / Coke)
Same as Example 1. However, the catalyst layer is not raised or lowered. There is no ventilation.
The outside of the reaction vessel was hit with a hammer (total of 300 hits).

(Test procedure)
The amount of coke falling during striking was measured in the same manner as in Example 1. In Comparative Example 2, the amount of coke falling was the scattered coke mass.

(Test results (Table 1))
In Table 1, “Initial” is the period of the first to fifteenth hits, and “End” is the period of the 271th to 300th hits. When hammering is performed, the effect of removing impurities similar to that of the present invention can be obtained in the initial stage. This effect decreases rapidly when the blow is continued, and at the end, more than half of the coke still remains in the catalyst layer. Despite this, almost no impurities could be removed.

  On the other hand, as shown in FIG. 11, in the present invention, the contaminant removal effect was maintained even during the “after initial period”. That is, it has been found that the removal of impurities according to this comparative example, which is simply imparting vibration to the catalyst layer, has a significantly shorter effective time than the present invention. From the above results, it was found that the ability to remove impurities from the catalyst layer according to the present invention was high.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

Claims (10)

A raw material gas supply unit for supplying a raw material gas for catalytic reaction;
A catalyst layer is formed by accommodating the bulk catalyst so that the bulk catalyst contacts the inner wall of the container, and the raw material gas is passed through the catalyst layer to reform the raw material gas. A catalytic reaction vessel to be produced;
The source gas inflow path and the reformed gas outflow path;
A catalyst holder which is installed below the inside of the catalyst reaction vessel to hold the catalyst layer, has air permeability and can be raised and lowered;
A continuous fixed bed catalyst reaction device comprising a drive mechanism for raising and lowering the catalyst holder,
Furthermore, a removal gas supply unit that supplies a removal gas for removing impurities in the catalyst layer to the catalyst reaction vessel;
A control unit that supplies the removal gas to the catalyst layer by controlling the removal gas supply unit during the raising and lowering of the catalyst holder by the drive mechanism,
The raw material gas contains coal dry distillation gas containing tar, and the contaminants in the catalyst layer are coke,
The removal gas supply unit can increase the supply flow rate of the removal gas higher than the supply flow rate of the raw material gas when reforming the raw material gas,
And the said removal gas supply part can supply the said removal gas from which the linear velocity in the said catalyst layer becomes 0.4 m / s or more vertically upwards, or 0.2 m / s or more vertically downwards A continuous fixed bed catalytic reactor characterized by the above.   The continuous fixed bed catalytic reactor according to claim 1, wherein the removal gas supply unit is configured such that the removal gas flows downward in the catalyst layer.   The removal gas supply unit is configured so that the removal gas flows upward in the catalyst layer, and is configured to be able to change the flow rate of the removal gas to two or more values. The continuous fixed bed catalytic reactor according to claim 1. Continuous fixed bed catalytic reactor according to any one of claims 1-3, wherein the raw material gas supply unit, characterized in that the Ru with the coal carbonization gas generator.   The source gas supply unit also serves as the removal gas supply unit, and is configured such that the source gas can be used as the removal gas, and the source gas as the removal gas to the catalytic reaction vessel The continuous fixed bed catalytic reactor according to any one of claims 1 to 4, further comprising a speed increasing portion for the supply flow rate of the raw material gas capable of increasing the supply flow rate. A gas reforming method using the apparatus according to any one of claims 1 to 4,
The raw material gas contains coal dry distillation gas containing tar, and the contaminants in the catalyst layer are coke,
When supplying the removal gas to the catalyst reaction vessel, the supply of the raw material gas is stopped, and the catalyst holder is moved up and down so that the linear velocity in the catalyst layer is vertically upward. A gas reforming method using a continuous fixed bed catalytic reactor, wherein the gas is supplied at 0.4 m / s or more, or 0.2 m / s or more vertically downward . A gas reforming method using the apparatus according to any one of claims 1 to 4,
The raw material gas contains coal dry distillation gas containing tar, and the contaminants in the catalyst layer are coke,
0.4m when supplying the stripping gas into the catalytic reaction vessel, said catalyst retainer to lift during supply of the raw material gas, the stripping gas, the linear velocity of said catalyst layer is vertically upward / S or more, or a gas reforming method using a continuous fixed bed catalytic reactor characterized by being fed vertically 0.2 m / s or more .   The gas reforming method using the continuous fixed bed catalytic reactor according to claim 6 or 7, wherein the removed gas is a non-reactive gas that does not react with the bulk catalyst.   9. The gas reforming method using a continuous fixed bed catalytic reactor according to claim 8, wherein the removed gas is nitrogen gas. A gas reforming method using the apparatus according to claim 5,
The raw material gas contains coal dry distillation gas containing tar, and the contaminants in the catalyst layer are coke,
When supplying the removal gas to the catalytic reaction vessel, the supply of the raw material gas is increased by an increase part of the supply flow rate of the raw material gas, and the catalyst holder is moved up and down to supply the raw material gas to the catalyst reaction vessel. A continuous fixed bed catalyst, characterized in that it is supplied as a removal gas so that the linear velocity in the catalyst layer is 0.4 m / s or more vertically upward or 0.2 m / s or more vertically downward. Gas reforming method using a reactor.

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