AU2007232919A1 - Bubble column type hydrocarbon synthesis reactor - Google Patents

Description

DECLARATION I, Toru ISHIKAWA of c/o SHIGA INTERNATIONAL PATENT OFFICE, GranTokyo South Tower, 1-9-2 Marunouchi, Chiyoda-ku, Tokyo, Japan, understand both English and Japanese, am the translator of the English document attached, and do hereby declare and state that the attached English document contains an accurate translation of PCT International Application PCT/JP2007/056911 as filed on March 29, 2007, and that all statements made herein are true to the best of my knowledge. Declared in Tokyo, Japan This 8th day of September ,2008 Toru ISHIKAWA OSP-27435AU 1 SPECIFICATION BUBBLE COLUMN TYPE HYDROCARBON SYNTHESIS REACTOR 5 TECHNICAL FIELD [0001] The present invention relates to a bubble column type hydrocarbon synthesis reactor, and particularly, to a reactor for performing a Fischer-Tropsch synthesis reaction by blowing a synthesis gas into a slurry having solid catalyst particles suspended in liquid hydrocarbons. Priority is claimed on Japanese Patent Application No. 2006-95020, filed 10 March 30, 2006, the content of which is incorporated herein by reference in its entirety. BACKGROUND ART OF THE INVENTION [0002] As one of the reaction systems of a Fischer-Tropsch synthesis reaction (hereinafter referred to as "FT reaction") which produces a hydrocarbon compound and 15 water from a synthesis gas which is mainly composed of hydrogen and carbon monoxide, a bubble column type slurry bed FT reaction system which carries out the FT reaction by introducing the synthesis gas into a slurry in which solid catalyst particles are suspended in liquid hydrocarbons is available. Further, a hydrocarbon compound synthesized by the FT reaction is mainly utilized as a raw material for fuel oil or lubrication oil. 20 [0003] In an FT reactor (hereinafter simply referred to as "reactor") available for this bubble column type slurry bed FT reaction system, the FT reaction is performed by introducing a synthesis gas as bubbles into a slurry having solid catalyst particles suspended in liquid hydrocarbons from a lower portion of the reactor. At this time, a liquid (slurry) is mixed inside the reactor by the airlift effect of ascending bubbles, or the 25 like. Meanwhile, if the liquid inside the reactor is agitated well as a whole by the OSP-27435AU 2 circulation (hereinafter referred to as "large circulation") over the whole region of the reactor in its height direction, bubbles including a number of gas hydrocarbons (mainly composed of light hydrocarbons of Cl to C 4 ) produced by the FT reaction strongly tend to be moved to the lower portion of the reactor by mixing (hereinafter referred as "back 5 mixing") of a fluid by a downward flow of the slurry. As a result, the reaction rate inside the reactor may be reduced throughout the reactor, and the reaction conversion rate of a synthesis gas which is a raw material may be reduced. [0004] In order to solve such a problem, the following method is conventionally performed in a general bubble column reactor (see Non-Patent Document 1). That is, 10 the inner space of the reactor is split in the height direction (vertical direction) of the reactor by a porous plate, etc., and the flow of the bubbles within the reactor is brought close to a plug flow (a state of no back flow of a fluid) which ascends through the reactor upward from below. Thereby, the mixing (large circulation) in the whole reactor can be suppressed. 15 [0005] NON-PATENT DOCUMENT 1: "Bubbles" Technique: Using, Making, and Excluding" Hideki Tsuge in collaboration with Hajime Uno (First Edition, Kogyo Chosakai Publishing Co., Ltd., April, 2004, pp. 75-81) DETAILED DESCRIPTION OF THE INVENTION 20 PROBLEMS TO BE SOLVED BY THE INVENTION [0006] However, in the bubble column type slurry bed FT reaction system, the flow rate of the liquid may be very small with respect to the volume of the reactor. In this case, the net ascending rate (superficial velocity within a column) of the liquid is close to zero. Therefore, if the porous plate is installed, the ascent of the bubbles is hindered by the 25 resistance of the porous plate, and the ascending rate of the slurry accompanying the OSP-27435AU 3 ascent of the bubbles is reduced, and a sufficient ascending rate of the slurry is not obtained. Therefore, the catalyst particles may be unevenly dispersed in the lower portion of the reactor, or may be deposited on the porous plate. Thus, the dispersed state of the catalyst particles may become worse. 5 [0007] The invention has been made in view of such problems, and the object of the invention is to provide a bubble column type hydrocarbon synthesis reactor for performing the Fischer-Tropsch synthesis reaction, capable of suppressing the back mixing of the bubbles within the reactor, and maintaining the dispersed state of catalyst particles well without hindering the upward flow of a slurry. 10 MEANS FOR SOLVING THE PROBLEMS [0008] The present inventors have intensively studied in order to solve the above object, and have found that if a member (for example, a baffle plate, etc.) which covers the vicinity of the side wall inside a reactor, and opens the central side of the reactor is 15 provided, and an inner space of the reactor is divided into a plurality of sections in the height direction, the back flow of bubbles between adjacent sections can be suppressed, and an upward flow of the bubbles and the slurry can be maintained on the central side of the reactor, and as a result, have contrived the invention on the basis of above knowledge. [0009] That is, a bubble column type hydrocarbon synthesis reactor of the invention 20 includes a reactor body containing a slurry having solid catalyst particles suspended in liquid hydrocarbons; a synthesis gas supplying section disposed in a lower portion of the reactor body to supply a synthesis gas including hydrogen and carbon monoxide as main components to the slurry; and a baffle member provided within the reactor body to hinder a downward flow of the slurry. 25 [0010] In the bubble column type hydrocarbon synthesis reactor of the invention, the OSP-27435AU 4 baffle member may cover a portion of a cross-section of the reactor body. [0011] In the bubble column type hydrocarbon synthesis reactor of the invention, the baffle member may be provided inside the reactor body so as to cover a region near a side wall of the reactor body and open the center of the reactor body and a region in the 5 vicinity of the center. [0012] In the bubble column type hydrocarbon synthesis reactor of the invention, the baffle member may be formed with a plurality of through-holes. [0013] In the bubble column type hydrocarbon synthesis reactor according to the invention, the through-holes may be sized such that the catalyst particles can pass through 10 the holes, or may be sized such that passage of bubbles including the synthesis gas or gas hydrocarbons produced by the reaction of the synthesis gas can be suppressed. [0014] In the bubble column type hydrocarbon synthesis reactor according to the invention, the diameter of the through-holes may be 10 times to 100 times the mean particle diameter of the catalyst particles. 15 [0015] In the bubble column type hydrocarbon synthesis reactor according to the invention, at least a portion of each of the through-holes may be formed in a substantially tapered shape of which the cross-sectional area becomes smaller downward. [0016] In the bubble column type hydrocarbon synthesis reactor of the invention, the baffle member may be inclined so as to become lower at the center of the reactor body 20 than at the side wall thereof. ADVANTAGEOUS EFFECTS OF THE INVENTION [0017] According to the invention, in a bubble column type hydrocarbon synthesis reactor for performing the Fischer-Tropsch synthesis reaction, the back mixing of the 25 bubbles within the reactor can be suppressed, and the dispersed state of catalyst particles OSP-27435AU 5 can be maintained well without hindering the upward flow of a slurry. Accordingly, according to the invention, the reaction conversion rate of the synthesis gas which is a raw material can be improved, and a reaction can be efficiently performed throughout the inner space of the reactor. 5 BRIEF DESCRIPTION OF THE DRAWINGS [0018] FIG. 1 is a longitudinal sectional view showing the overall configuration of an FT reactor according to a first embodiment of the invention. FIG. 2 is a perspective view showing a baffle plate provided in the FT reactor 10 shown in FIG. 1. FIG. 3 is a perspective view showing a modified example of the baffle plate provided in the FT reactor shown in FIG. 1. FIG. 4 is a sectional view showing a through-hole formed in the baffle plate shown in FIG 2. 15 FIG. 5 is a sectional view showing a modified example of the through-hole formed in the baffle plate shown in FIG. 2. FIG. 6 is a sectional view showing a modified example of the through-holes formed in the baffle plate shown in FIG. 2. FIG. 7 is a sectional view showing a modified example of the through-hole 20 formed in the baffle plate shown in FIG. 2. FIG. 8 is a sectional view showing a modified example of the through-hole formed in the baffle plate shown in FIG. 2. FIG. 9 is a sectional view showing a modified example of the through-hole formed in the baffle plate shown in FIG. 2. 25 FIG. 10 is an explanatory view showing the flow of a slurry and bubbles inside OSP-27435AU 6 the FT reactor shown in FIG. 1. FIG. 11 is an explanatory view showing the flow of the slurry and bubbles in the vicinity of the baffle plate shown in FIG. 2. FIG. 12 is an explanatory view showing the flow of the slurry and bubbles in the 5 vicinity of the baffle plate shown in FIG. 3. FIG. 13 is an explanatory view showing the flow of the slurry and bubbles in the vicinity of the through-holes formed in the baffle plate shown in FIG. 2. FIG. 14 is a longitudinal sectional view showing the overall configuration of an FT reactor according to a second embodiment of the invention. 10 FIG. 15 is a longitudinal sectional view showing the overall configuration of an FT reactor according to a third embodiment of the invention. FIG. 16 is a longitudinal sectional view showing the overall configuration of a conventional FT reactor. 15 Reference Numerals [0019] 100,200, 300: SYNTHESIS REACTOR 110,210,310: REACTORBODY 120, 220, 320: SLURRY 122: LIQUID HYDROCARBON 20 124: CATALYST PARTICLE 130: BUBBLE 140, 240, 340: DISTRIBUTOR (SYNTHESIS GAS SUPPLYING SECTION) 142, 242, 342: SYNTHESIS GAS INJECTION PORT 150, 250, 350: BAFFLE PLATE (BAFFLE MEMBER) 25 152, 252, 352: THROUGH-HOLE OSP-27435AU 7 152a, 152b, 152c, 152d: TAPERED PORTION 153: STRAIGHT PORTION BEST MODE FOR CARRYING OUT THE INVENTION 5 [0020] Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. In addition, in the present specification and drawings, duplicate description is omitted by giving the same reference numerals to constituent elements having substantially the same functional configurations. [0021] 10 (Configuration of Conventional Bubble Column Reactor) First, the configuration of a conventional bubble column reactor 1 will be described with reference to FIG. 16. In addition, FIG. 16 is a vertical sectional view showing the overall configuration of the conventional bubble column reactor 1. In addition, as the bubble column reactor, a slurry bed type reactor in which solid catalyst 15 particles are dispersed in a liquid will be exemplified and described in the following description. However, the conventional bubble column reactor 1 is not limited to this slurry bed type reactor, but may be a bubble column reactor which produces gas by a reaction or a bubble column reactor including a gas component which is not involved in a reaction in a source gas. For example, the conventional bubble column reactor may be a 20 bubble column reactor in which a liquid which does not include a solid catalyst is contained. [0022] As shown in FIG. 16, the conventional bubble column reactor 1 mainly includes a reactor body 10, a distributor 40 as an example of a source gas supplying section, and a porous plate 50. 25 [0023] The reactor body 10, a substantially cylindrical metallic vessel, contains a slurry OSP-27435AU 8 20 having solid catalyst particles 24 suspended in a liquid (for example, liquid hydrocarbons) 22. Further, a slurry inlet 11 for introducing the slurry 20 into the reactor body 10 is provided at the bottom of the reactor body 10. A slurry outlet 12 for discharging the slurry 20 is provided at the side wall of the reactor body 10. A gas 5 outlet 14 for discharging a gas produced by a reaction or an unreacted source gas is provided at the top of the reactor body 10. In addition, the positions in which the slurry inlet 11, the slurry outlet 12, and the gas outlet 14 are provided are not limited to the above-mentioned positions. [0024] In the reactor body 10 configured as described above, the liquid 22 is discharged 10 from the slurry outlet 12 together with the catalyst particles 24, and the catalyst particles 24 are separated from the liquid. Then, a portion of the liquid is extracted out of a system (to the outside of the reactor body 10), and the remainder of the liquid is returned to the inside of the reactor body 10 from the slurry inlet 11 together with the separated catalyst particles 24. 15 [0025] Here, the flow rate of the liquid 22 returned to the inside of the reactor body 10 from the slurry inlet 11 varies depending on individual reaction systems. [0026] Further, in a reaction system in which the liquid 22 is produced by a reaction, and the catalyst particles 24 are extracted to the outside of the reactor body 10 by using a filter, etc., the flow rate of the liquid 22 returned to the inside of the reactor body 10 from 20 the slurry inlet 11 may be set to zero. [0027] The distributor 40 is arranged at a lower portion of the reactor body 10 to supply the source gas into the slurry 20. A plurality of source gas injection ports 42 are provided at an upper portion of the distributor 40. In addition, the number and position of the source gas injection ports 42 to be provided are not particularly limited. 25 [0028] The source gas supplied through the distributor 40 from the outside is injected OSP-27435AU 9 toward the upper portion (direction indicated by arrows in the drawing) from the source gas injection ports 42. The source gas introduced from the distributor 40 in this way becomes bubbles 30. These bubbles are dissolved in the liquid 22 when they flow through the slurry 20 upward from the bottom of the reactor body 10 in the height 5 direction (the vertical direction). As the dissolved source gas component contacts with the catalyst particles 24, a predetermined reaction is performed. [0029] Further, as described above, the source gas is introduced from the bottom of the reactor body 10, and the introduced source gas is made into bubbles 30 and ascends inside the reactor body 10. Thereby, inside the reactor body 10, an upward flow K of 10 the slurry 20 is generated mainly at the center portion (that is, in the vicinity of the center axis of the reactor body 10) inside the reactor body 10, and a downward flow J of the slurry 20 is generated in the vicinity of the side wall of the reactor body 10 (that is, in the vicinity of the inner peripheral portion). Thereby, the flow (large circulation) that the slurry 20 is circulated through the whole inside of the reactor body 10 is produced. Here, 15 the arrows K and J in FIG. 16 represent the direction of flows of the slurry 20 which are mainly produced within the reactor body 10. These flows change with time, and are not flows through a fixed place in a fixed direction at a fixed speed. [0030] If the slurry 20 inside the reactor body 10 is agitated well as a whole by such a large circulation, the bubbles 30 of which the concentration of the source gas has become 20 small strongly tend to move to the lower portion of the reactor body 10 by back mixing. As a result, the reaction rate inside the reactor body 10 may be reduced as a whole, and the reaction conversion rate of the source gas may be reduced. [0031] In order to solve such a problem, in the conventional bubble column reactor 1, the porous plate 50 is provided in the reactor body 10, for example, as a barrier member 25 which partially hinders the flow within the reactor body 10. The porous plate 50, a OSP-27435AU 10 substantially disk-like member provided so as to divide the inner space of the reactor body 10 into a plurality of sections in the height direction (vertical direction), suppresses the bubbles 30 of which the concentration of the source gas has become low from flowing into the lower portion of the reactor body 10. The porous plate 50 is provided with a 5 plurality of through-holes 52, and the bubbles 30 and the slurry 20 can pass through the through-holes 52. Moreover, the slurry 20 (or the liquid 22 which does not include the catalyst particles 24) is extracted to the outside of the reactor body 10 and is circulated such that the slurry 20 (or the liquid 22 which does not include the catalyst particles 24) flows upward from the bottom of the reactor body 10. This prevents the bubbles 30 10 from flowing downward from above via a barrier member, such as the porous plate 50. [0032] By providing a barrier member, such as the porous plate 50, in this manner, the flow of the slurry 20 within the reactor body 10 is brought close to a plug flow (a state of no back flow of a fluid) which goes through the reactor body 10 upward from below. Thereby, overall mixing (large circulation) inside the reactor body 10 can be suppressed. 15 [0033] Meanwhile, in a bubble column type slurry bed FT reaction system, the flow rate of the slurry 20 may be very small compared with the volume of the reactor body 10. In this case, the net ascending rate of the slurry 20 is close to zero. Therefore, if the porous plate 50 is installed similarly to the conventional bubble column reactor 1, the ascent of the bubbles 30 is hindered due to the resistance of the porous plate 50 when the bubbles 20 30 and the slurry 20 pass through the porous plate 50. Further, the rate of the upward flow K of the slurry 20 accompanying the ascent of the bubbles 30 is reduced, and the rate of the upward flow K of the slurry 20 is not sufficiently obtained. Therefore, as shown in FIG. 16, the catalyst particles 24 may be unevenly dispersed in the lower portion of the reactor body 10, or may be deposited on the porous plate 50. Thus, the 25 dispersed state of the catalyst particles 24 may become worse. If the dispersed state of OSP-27435AU 11 the catalyst particles 24 is poor as such, the reaction rate decreases in the region where the concentration of the catalyst particles 24 is small, and the reaction efficiency degrades throughout the inside the reactor body 10. [0034] Thus, in the FT reactor according to the invention, instead of the porous plate 50, 5 a member which covers the vicinity of the side wall inside the reactor body 10 and opens the central side thereof is provided. Hereinafter, the FT reactor according to the invention will be described in detail referring to specific embodiments. [0035] 10 (First Embodiment) First, the configuration of the bubble column type slurry bed FT synthesis reactor 100 (hereinafter simply referred to as "FT reactor 100") as an example of the bubble column type hydrocarbon synthesis reactor according to the first embodiment of the invention will be described with reference to FIG. 1. In addition, FIG. 1 is a vertical 15 sectional view showing the overall configuration of the FT reactor 100 according to this embodiment. [0036] As shown in FIG. 1, the FT reactor 100 according to this embodiment mainly includes a reactor body 110, a distributor 140 as an example of a synthesis gas supplying section according to the invention, and a baffle plate 150 as an example of a baffle 20 member according to the invention. [0037] The reactor body 110 is a substantially cylindrical metallic vessel the diameter of which is about 1 to 20 meters, preferably about 2 to 10 meters. The height of the reactor body 10 is about 10 to 50 meters, preferably about 15 to 45 meters. A slurry 120 having solid catalyst particles 124 suspended in liquid hydrocarbons (product of the FT 25 reaction) 122 is contained in the reactor body 10. Further, a slurry inlet 111 for OSP-27435AU 12 introducing the slurry 120 into the reactor body 110 is provided at the bottom of the reactor body 110. A slurry outlet 112 for discharging the slurry 120 is provided at the side wall of the reactor body 110. A gas outlet 114 for discharging a light hydrocarbon gas produced by the FT reaction or an unreacted synthesis gas is provided at the top of 5 the reactor body 110. In addition, the positions in which the slurry inlet 111, the slurry outlet 112, and the gas outlet 114 are provided are not limited to the above-mentioned positions. [0038] The distributor 140, which is an example of a reaction gas supplying section according to this embodiment, is disposed at the lower portion of the reactor body 110 to 10 supply a synthesis gas including hydrogen and carbon monoxide as main components into the slurry 120. A plurality of synthesis gas injection ports 142 are provided at an upper portion of the distributor 140. In addition, the number and position of synthesis gas injection ports 142 to be provided are not particularly limited. [0039] The synthesis gas supplied through the distributor 140 from the outside is 15 injected, for example, upward (directions indicated by arrows in the drawing) from the synthesis gas injection ports 142. The synthesis gas introduced from the distributor 140 in this way becomes bubbles 130. These bubbles 130 are dissolved in the liquid hydrocarbons 122 when they flow through the slurry 120 upward from the bottom of the reactor body 110 in the height direction (the vertical direction). As the dissolved 20 synthesis gas component contacts with the catalyst particles 124, the synthesis reaction (FT synthesis reaction) is performed. [0040] The baffle plate 150 is provided inside the reactor body 110 so as to cover a region near the side wall of the reactor body 110 and open the center of the reactor body 110 and a region in the vicinity of the center. The inner space of the reactor body 110 is 25 divided into a plurality of sections in the height direction by the baffle plate 150. In this OSP-27435AU 13 embodiment, two baffle plates 150 are provided inside the reactor body 110. Thereby, the inner space of the reactor body 110 is divided into three sections. [0041] Although described below in detail, as the baffle plate 150 is provided so as to cover the region near the side wall of the reactor body 110 in this way, the bubbles 130 5 including a number of light hydrocarbons produced by the FT reaction are circulated through the sections where they exist. As a result, the bubbles become difficult to flow into other sections. This can suppress the back flow (back mixing) between each section. Further, as the baffle plate 150 is provided so as to open the center of the reactor body 110 and a region in the vicinity of the center, the upward flow of the slurry 120 which is 10 going to ascend through the center of the reactor body 110 is not hindered. [0042] Here, the number of baffle plates 150 or the vertical length L of each section can be suitably determined according to the height of the reactor body 110. Specifically, the length L in the height direction of each of the sections of the reactor body 110 divided by the baffle plate 150 is preferably about 0.5 to 10 times, more preferably about 1 to 5 times 15 the inner diameter D of the reactor body 110. [0043] If the ratio of the length L in the height direction of each section of the reactor body 110 to the inner diameter D of the reactor body 110, i.e., L/D, deviates from the above range and is too small, sufficient circulation flow will not be developed in each section, but the back mixing will be suppressed excessively. Therefore, the dispersed 20 state of the catalyst particles 124 becomes worse, or the residence time of bubbles 130 becomes short due to the shortcut of the bubbles 130. As a result, there is a possibility that the reaction conversion rate of the synthesis gas which is a raw material may decrease. On the other hand, if the L/D deviates from the above range and is too large, the effect of dividing by the baffle plate 150, i.e., the effect of suppressing the back 25 mixing will not be sufficiently exhibited.

OSP-27435AU 14 [0044] Hereinafter, the configuration of the baffle plate 150 according to this embodiment will be described in detail with reference to FIGS. 2 to 9. In addition, FIG. 2 is a perspective view showing the configuration of the baffle plate 150 according to this embodiment, and FIG. 3 is a perspective view showing the configuration of a baffle-plate 5 150' according to a modified example of this embodiment. Further, FIGS. 4 to 9 are respectively sectional views showing exemplary configurations of the through-holes 152 according to this embodiment. [0045] As shown in FIG. 2, the baffle plate 150 is a substantially disk-like member in the center of which an opening 150a is formed. By this baffle plate 150, a region near 10 the side wall of the reactor body 110 is covered, and the center of the reactor body 110 and a region near the center are opened. In addition, the baffle member of the invention is not limited to one in which the opening 150a is formed in the center of substantially disk-like member, like just the baffle plate 150 according to this embodiment, but has only to be provided with a space opened in the center of the reactor body 10 and in a 15 region near the center. For example, as shown in FIG. 3, the baffle member may be a baffle-plate 150' in which two substantially semi-lunar plates provided at the side wall of the reactor body 10 (in other words, one in which substantially a disk-like baffle plate is divided into three pieces, and an open portion 150'a is formed by removing a central divided piece) make one set. 20 [0046] Here, the area Ac of the portion (the opening 150a in the example of FIG. 2, and the open portion 150' a in the example of FIG. 3) in which the above baffle plate 150 (or 150' (omitted below)) is opened is preferably about 10 to 90%, more preferably about 35 to 65%, of the area At of the horizontal section inside the reactor body 10. [0047] If the ratio of the area Ac of the portion in which the baffle plate 150 to the area 25 At of the horizontal section inside the reactor body 10 is opened, i.e., Ac/At, deviates OSP-27435AU 15 from the above range and is too small, the upward flow of the bubbles 130 and the slurry 120 is hindered. Thus, there is a possibility that the sufficient dispersion effect of the catalyst particles 124 cannot be obtained. On the other hand, if the Ac/At deviates from the above range and is too large, the effect of dividing by the baffle plate 150, i.e., the 5 effect of suppressing the back mixing will not be sufficiently exhibited. [0048] Further, the baffle plate 150 is provided with a plurality of through-holes 152 (or 152' (omitted below)). The through-holes 152 are formed with a suitable size so that the passage of the liquid hydrocarbons 122 and the catalyst particles 124 can be allowed, and the passage of the bubbles 130 including light hydrocarbons produced by the FT reaction 10 can be controlled. By setting the size of the through-holes 152 as described above, the catalyst particles 124 can be prevented from clogging the through-holes 152. Further, the bubbles 130 can be kept from passing through the through-holes 152 of the baffle plate 150 downward from above with the downward flow of the slurry 120, or the ascending bubbles 130 can be kept from passing through the baffle plate 150 upward 15 from below. [0049] More specifically, in a case where the cross-section of the through-holes 152 is substantially circular, the diameter of the through-holes 152 is preferably 10 to 100 times, more preferably 30 to 50 times the mean particle diameter of the catalyst particles 124. Further, as the catalyst particles 124 according to this embodiment, their mean particle 20 diameter is preferably 10 to 1000 pm, more preferably 20 to 500 pm. About 100 pm is still more preferable. For example, in a case where those of which the mean particle diameter is about 100 ptm are used as the catalyst particles 124, the diameter of the through-holes 152 is preferably about 1 to 10 mm, more preferably about 3 to 5 mm. The diameter of the through-holes 152 is set to 10 or more times the mean particle 25 diameter of the catalyst particles 124 because it is necessary to make the diameter of the OSP-27435AU 16 through-holes sufficiently larger than the diameter of the catalyst particles so that the catalyst particles 124 which are going to deposit on the baffle plate 150 can pass through the baffle plate 150 downward from above without clogging the through-holes 152. Further, the diameter of the through-holes 152 is set to 100 or less times the mean particle 5 diameter of the catalyst particles 124 because, if the diameter of the through-holes 152 is too large, the flow rate of the slurry 120 which passes through the through-holes 152 becomes large, and consequently, the possibility that the bubbles 130 (of which the size is several millimeters to several centimeters) pass through the through-holes 152 together with the slurry 120 increases. In addition, this is because the possibility that the 10 ascending bubbles 130 pass through the through-holes 152 increases. In addition, the diameter of the through-holes 152 means a characteristic length (for example, if the cross-section of a through-hole 152 is circular, the characteristic length is the diameter of the hole, or if the cross-section is square, the characteristic length is the length of one side) of the narrowest portion of the through-hole 152, in a case where the diameter of the 15 through-hole 152 is not constant, for example, in a case where the through-hole 152 is provided with a tapered portion as will be described below. [0050] Further, the opening ratio 6 of the through-holes 152, i.e., the ratio (s = Ah/Ap) of a total of the opening areas Ah of the through-holes 152 to the area Ap (excluding the area of the central opening 150a) of the baffle plate 150 is preferably 1 to 50%, more 20 preferably 5 to 25%. The opening ratio c is set to 1% or more (preferably 5% or more) because it is necessary to obtain a sufficient amount of downward flow of the slurry 120 which passes through the baffle plate 150. Here, if the diameter of the through-holes 152 is increased excessively in order to increase the opening ratio e, the possibility that bubbles 130 may pass through the through-holes 152 increases as described above, which 25 is not preferable. Further, if the number of through-holes 152 is increased in order to OSP-27435AU 17 increase the opening ratio s, the area of the upper surface of the baffle-plate 150 with a sufficient size cannot be secured when a tapered portion to be described is provided, which is not preferable. From such a viewpoint, the opening ratio 6 is required to be 50% or less (preferably 25% or less). In addition, the opening area of a through-hole 5 152 used for calculation of this opening ratio s means an opening area of the narrowest portion of the through-hole 152, in a case where the diameter of the through-hole 152 is not constant, for example, in a case where the through-hole 152 is provided with a tapered portion as will be described below. [0051] For example, as shown in FIG. 4, a through-hole 152 may be formed such that 10 the cross-sectional area (opening area) of the through-holes 152 is constant. Further, as shown in FIG. 5, a tapered portion 152a the cross-sectional area of which becomes small downward may be provided at at least a portion of a through-hole 152, for example, the upper surface of the baffle-plate 150. [0052] The shape of this tapered portion is not limited to the case shown in FIG. 5, but 15 arbitrary shapes can be adopted so long as they are shapes the cross-sectional area of which becomes small downward. For example, as shown in FIGS. 6 to 8, a shape (FIG. 6) in which a straight portion 153 (vertical length R) the cross-sectional area of which is constant is provided above a tapered portion 152b, a shape (FIG. 7) in which the vertical cross-section of a tapered portion 152c is curved, a step-like shape (FIG. 8) in which a 20 tapered portion 152d is composed of a plurality of steps, etc. can be adopted. [0053] By providing at least a portion of a through-hole 152 with a tapered portion (152a, 152b, 152c, 152d, etc.), the area of the flat portion of the upper surface of the baffle plate 150 can be minimized, and thus any deposition of the catalyst particles 124 on the upper surface of the baffle plate 150 can be suppressed to the minimum. Further, 25 by providing a tapered portion to increase the cross-sectional area of a through-hole 152 OSP-27435AU 18 at the upper surface of the baffle-plate 150, the flow rate of the slurry 120 to pass through the through-hole 152 on the upper surface of the baffle-plate 150 can be reduced. This can further improve the effect of keeping the bubbles 130 from passing through the through-holes 152 together with the slurry 120. 5 [0054] In addition, although the shape of the (horizontal) cross-section of the through holes 152 can be made substantially circular as shown in FIG. 2, FIG. 3, etc., it is not limited to the substantially circular shape, and may be other shapes (for example, a substantially square shape, etc.). [0055] Further, the ratio a (= A 1 /Ao) of the cross-sectional area Al (hereinafter referred 10 to as "the upper surface cross-sectional area A,") of a through-hole 152 on the side of the upper surface of the baffle plate 150 to the cross-sectional area A 0 (hereinafter referred to as "the lower surface cross-sectional area Ao") of the through-hole on the side of the lower surface of the baffle plate 150 can be set to 1 < a 5 100. [0056] This reason is that, in order to enhance the separation effect (effect of keeping 15 the bubbles 130 from passing through the through-holes 152 together with the slurry 120) of the bubbles 130 in the tapered portion 152a, etc., larger a is preferable. This is because the flow rate of the slurry 120 which passes through the through-holes 152 can be further reduced by increasing a. [0057] Specifically, the numeric range of a is determined from the following 20 viewpoints. That is, in a case where the lower surface cross-sectional area A 0 and the upper surface cross-sectional area A 1 are equal to each other (in a case where a tapered portion is not provided like FIG. 4), since a = 1 is established, it is necessary to set a to 1 or more. In addition, although it is also possible to set a < 1, i.e., A 0 > A

I

, the flow rate on the side of the lower surface of the slurry 120 which passes through the through 25 holes 152 is reduced. Thereby, bubbles may pass through the baffle plate 150 upward OSP-27435AU 19 from below. Thus, cc _ 1 is preferable. On the other hand, since the upper limit of a is determined by the lower limit of the opening ratio c, and the maximum value of a is set to c = 100 at e = 1% (lower limit), c <: 100 is preferable. [0058] Further, in a case where the tapered portion 152a of which the vertical cross 5 section as shown in FIG. 9 has a straight inclined surface is applied as the tapered portion, the angle (aperture angle) 0 of this inclined surface is preferably about 30 to 60 degrees with respect to the central axis of the through hole 152. As for the aperture angle 0, the aperture angle 0 is required to be made small (sharply inclined) such that catalyst particles 124 flow down through the through-holes 152 smoothly. However, if the 10 aperture angle 0 is too small, it will be necessary to increase the thickness of a baffle plate 150 in order to secure the required upper surface cross-sectional area A,. On the other hand, if the aperture angle 0 is too large, it will not be substantially different from the case where no tapered portion is provided. From such a viewpoint, it is preferable that the aperture angle 0 be about 30 to 600. 15 [0059] Further, although the array of the through-holes 152 is not particularly limited, it is preferable that the through-holes be arrayed substantially uniformly as a whole baffle plate 150. Moreover, in order to reduce the area of the flat portion of the baffle plate 150, it is preferable that the through-holes 152 be arrayed in a triangular pattern. Thus, by arraying the through-holes 152 in a triangular pattern, deposition of the catalyst 20 particles 124 on the baffle plate 150 can be suppressed. [0060] The configuration of the FT reactor 100 according to this embodiment has been described hitherto with reference to FIGS. 1 to 9. Next, the functions and operation of the FT reactor 100 will be described with reference to FIGS. 10 to 13, while showing the flow of the slurry 120 and bubbles 130 inside the reactor body 110. In addition, FIG. 10 25 is an explanatory view showing the flow of the slurry 120 and bubbles 130 in the whole OSP-27435AU 20 inside of the reactor body 110 according to this embodiment. FIG. 11 and FIG. 12 are explanatory views showing the flow of the slurry 120 and bubbles 130 in the vicinity of the baffle plate 150 (or 150') according to this embodiment. In addition, FIG. 13 is an explanatory view showing the flow of the slurry 120 and bubbles 130 in the vicinity of 5 the through-holes 152 according to this embodiment. Here, the arrows in FIGS. 10 to 13 represent the direction of flows which are mainly produced within the reactor body 110. These flows change with time, and are not flows through a fixed place in a fixed direction at a fixed speed. [0061] First, the flow of the slurry 120 and bubbles 130 in the whole inside of the 10 reactor body 110 and in the vicinity of the baffle-plate 150 (or 150') will be described with reference to FIGS. 10 to 12. As shown in FIG. 10, the synthesis gas introduced from the bottom of the reactor body 110 through the synthesis gas injection port 142 of the distributor 140 become the bubbles 130, and ascends through the inside of the reactor body 110. Thereby, inside the reactor body 110, the upward flow A of the slurry 120 is 15 provided mainly in the central portion (center of the reactor body 110 and a region near the center), and the downward flow of the slurry is produced mainly in the vicinity of the side wall of the reactor body 110. [0062] However, in this embodiment, the baffle plate 150 is provided. Thus, the flow (large circulation) that the bubbles 130 are circulated through the whole inside of the 20 reactor body 110 together with the slurry 120 is not produced unlike before. That is, the baffle plate 150 is provided so as to cover the region in the vicinity of the side wall of the reactor body 110. Therefore, the flow of the bubbles 130 including a number of light hydrocarbons produced by the FT reaction, as indicated by an arrow B of FIGS. 10 and 11, is hindered on the side of the upper surface and lower surface of the baffle plate 150, 25 and thus, the bubbles will be circulated only in the sections split by the baffle plate 150.

OSP-27435AU 21 Therefore, the bubbles 130 can be kept from flowing back between each section (back mixing). Accordingly, since the bubbles 130 including a number of light hydrocarbons can be kept from being circulated in the whole inside of the reactor body 110, the reaction conversion rate of the synthesis gas can be increased. 5 [0063] On the other hand, in this embodiment, the baffle plate 150 is provided such that the center of the reactor body 110 and the region near the center are opened. Therefore, unlike before, as shown in FIGS. 10 and 11, the upward flow A of the slurry 120 and bubbles 130 in the central portion of the reactor body 110 is not hindered. Accordingly, the catalyst particles 124 can be kept from being unevenly dispersed in the lower portion 10 of the reactor body 110, and the dispersed state of the catalyst particles 124 can be maintained well. [0064] Moreover, in this embodiment, a plurality of through-holes 152 are provided in the baffle plate 150. Therefore, as indicated by an arrow C of FIG. 10, the slurry including the liquid hydrocarbons 122 and the catalyst particles 124 passes through the 15 through-holes 152, and flows down toward the lower portion of the reactor body 110. Accordingly, deposition of the catalyst particles 124 onto the baffle-plate 150 can be prevented by making the catalyst particles 124 deposited on the baffle plate 150 flow down from the top of the baffle plate 150 through the through-holes 152. Further, by providing the through-holes 152 to secure the downward flow C of the slurry 120 which 20 passes through the baffle plate 150, the upward flow A of the slurry 120 and bubbles 130 in the opening 150a of the baffle plate 150 can be further promoted. As such, by preventing the deposition of the catalyst particles 124 onto the baffle-plate 150, and by promoting the upward flow A of the slurry 120 which passes through the baffle plate 150, the dispersed state of the catalyst particles 124 can be kept better. 25 [0065] In addition, the above description is also the same in a case where the baffle- OSP-27435AU 22 plate 150' according to the modified example of this embodiment as shown in FIG. 12 is used. [0066] Next, the functions and operation of the through-holes 152 will be described in more detail with reference to FIG. 13. As shown in FIG. 13, the flow of the bubbles 130 5 including a number of light hydrocarbon gases produced by the FT reaction, as indicated by the arrow B, is hindered by the baffle plate 150. Thus, the bubbles can be kept from passing through the baffle plate 150 and moving between the sections adjacent to each other. Further, the catalyst particles 124, as indicated by the arrow Cl 1, are directed toward the through-holes 152 together with the downward flow of the slurry 120, and as 10 indicated by the arrow C2, pass through the through-holes 152, and flow to the lower portion of the reactor body 110. [0067] If the rate of the flow B of the bubbles 130 and the rate of the flow Cl of the catalyst particles 124 (and liquid hydrocarbons 122) are compared, the rate of the flow B is faster than the rate of the flow Cl. Therefore, the bubbles 130 with smaller specific 15 gravity compared with the slurry 120 hardly pass through the through-holes 152 together with the flow Cl of the slurry 120, etc. Moreover, if the tapered portion 152a is provided in the through-holes 152, the rate of the flow Cl of the slurry 120 which passes through the upper surface of the through-holes 152 can be further reduced, and thereby, the effect of keeping the bubbles 130 passing through the through-holes 152 together with 20 the slurry 120 can be further improved. [0068] The bubbles 130 are circulated in each section as mentioned above, and the slurry 120 passes through the baffle plate 150, so that they can be circulated in the whole reactor body 110. [0069] 25 (Second Embodiment) OSP-27435AU 23 Next, the configuration of the bubble column type slurry bed FT synthesis reactor 200 (hereinafter simply referred to as "FT reactor 200") as an example of the bubble column type hydrocarbon synthesis reactor according to the second embodiment of the invention will be described with reference to FIG. 14. In addition, FIG. 14 is a 5 vertical sectional view showing the overall configuration of the FT reactor 200 according to this embodiment. [0070] As shown in FIG. 14, the FT reactor 200 according to this embodiment mainly includes a reactor body 210, a distributor 240 as an example of a synthesis gas supplying section according to this embodiment, and a baffle plate 250 as an example of a baffle 10 member according to this embodiment. [0071] A slurry 220 is contained in the reactor body 210. Further, a slurry inlet 211 for introducing the slurry 220 into the reactor body 210 is provided at the bottom of the reactor body 210. A slurry outlet 212 for discharging the slurry 220 is provided at the side wall of the reactor body 210. A gas outlet 214 for discharging a light hydrocarbon 15 gas produced by the FT reaction or an unreacted synthesis gas is provided at the top of the reactor body 210. [0072] The distributor 240, which is an example of a reaction gas supplying section according to this embodiment, is disposed at the lower portion of the reactor body 210 to supply a synthesis gas including hydrogen and carbon monoxide as main components 20 into the slurry 220. A plurality of synthesis gas injection ports 242 are provided at an upper portion of the distributor 240. [0073] The baffle plate 250 is provided inside the reactor body 210 so as to cover a region near the side wall of the reactor body 210 and open the center of the reactor body 210 and a region in the vicinity of the center. The inside of the reactor body 210 is 25 divided into a plurality of sections in the height direction by the baffle plate 250.

OSP-27435AU 24 Further, the baffle plate 250 is provided with a plurality of through-holes 252. [0074] In the FT reactor 200 according to this embodiment, by providing this configuration, an upward flow D of the synthesis gas and the slurry 220 from the distributor 240 inside the reactor body 10 can ascend through an open portion provided in 5 the center of the baffle plate 250. Further, the bubbles including a number of light hydrocarbons produced by the FT reaction hardly flow into other sections by the baffle plate 250, and a circulation flow E in the section where the bubbles exist is produced. Moreover, the slurry 220 passes through the through-holes 252 to produce a downward flow F. Here, the arrows in FIG. 14 represent the direction of flows which are mainly 10 produced within the reactor body 210. These flows change with time, and are not flows through a fixed place in a fixed direction at a fixed speed. [0075] Here, in the FT reactor 200 according to this embodiment, unlike the above described first embodiment, the baffle plate 250 is installed such that its center becomes lower than a peripheral edge near the side wall of the reactor body 110, that is, so as to 15 incline downward toward the center of the reactor body 110. As such, in addition to providing the through-holes 252, the effect of preventing deposition of the catalyst particles onto the baffle-plate 250 can be further improved by making the baffle plate 250 incline downward. [0076] In addition, since the configuration and working effects of the FT reactor 200 20 other than the above are the same as those of the FT reactor 100 according to the above described first embodiment, detailed description thereof is omitted. [0077] (Third Embodiment) Next, the configuration of the bubble column type slurry bed FT synthesis 25 reactor 300 (hereinafter simply referred to as "FT reactor 300") as an example of the OSP-27435AU 25 bubble column type hydrocarbon synthesis reactor according to the third embodiment of the invention will be described with reference to FIG. 15. In addition, FIG. 15 is a vertical sectional view showing the overall configuration of the FT reactor 300 according to this embodiment. 5 [0078] As shown in FIG. 15, the FT reactor 300 according to this embodiment mainly includes a reactor body 310, a distributor 340 as an example of a synthesis gas supplying section according to this embodiment, and a baffle plate 350 as an example of a baffle member according to this embodiment. [0079] A slurry 320 is contained in the reactor body 310. Further, a slurry inlet 311 10 for introducing the slurry 320 into the reactor body 310 is provided at the bottom of the reactor body 310. A slurry outlet 312 for discharging the slurry 320 is provided at the side wall of the reactor body 310. A gas outlet 314 for discharging a light hydrocarbon gas produced by the FT reaction or an unreacted synthesis gas is provided at the top of the reactor body 310. 15 [0080] The distributor 340, which is an example of a reaction gas supplying section according to this embodiment, is disposed at the lower portion of the reactor body 310 to supply a synthesis gas including hydrogen and carbon monoxide as main components into the slurry 320. A plurality of synthesis gas injection ports 342 are provided at an upper portion of the distributor 340. 20 [0081] The baffle plate 350 is provided inside the reactor body 310 so as to cover a portion of the cross-section of the reactor body 310. The inside of the reactor body 310 is divided into a plurality of sections in the height direction by the baffle plate 350. Further, the baffle plate 350 is provided with a plurality of through-holes 352. Specifically, in the FT reactor 300 according to this embodiment, unlike the above 25 described first and second embodiments, baffle plates 350 are installed on both sides OSP-27435AU 26 inside the reactor body 310 so as to become alternate. At the boundary between each section, one side of the cross-section inside the reactor body 310 is opened and the other side is covered, by the baffle plate 350. [0082] In the FT reactor 300 according to this embodiment, by providing this 5 configuration, an upward flow G of the synthesis gas and the slurry 320 from the distributor 340 inside the reactor body 310 can ascend through an open portion which is not covered by the baffle plate 350. Further, the bubbles including a number of light hydrocarbons produced by the FT reaction hardly flow into other sections by the baffle plate 350, and a circulation flow H in the section where the bubbles exist is produced. 10 Moreover, the slurry 320 passes through the through-holes 252 to produce a downward flow I. Here, the arrows in FIG. 15 represent the direction of flows which are mainly produced within the reactor body 310. These flows change with time, and are not flows through a fixed place in a fixed direction at a fixed speed. [0083] As such, by installing the baffle plates 350 so as to become alternate, the upward 15 flow G can be prevented from being biased toward one side within the reactor body 310, and the slurry 320 can be prevented from stagnating on the other side, or the mixed state of the slurry 320 can be prevented from getting worse. [0084] In addition, since the configuration and working effects of the FT reactor 300 other than the above are the same as those of the FT reactor 100 according to the above 20 described first embodiment, detailed description thereof is omitted. [0085] Although the preferred embodiments of the invention have been described with reference to the accompanying drawings, it is needless to say that the invention is not limited to such embodiments. It is apparent to those skilled in the art that various alternations or modifications can be made in the category as set forth in the claims, and it 25 will be understood that these alternations or modifications naturally belong to the OSP-27435AU 27 technical scope of the invention. [0086] For example, although the case where the baffle member is the plate-like baffle plate 150, 250, or 350 has been described in the above-described embodiment, the shape of the baffle member is not limited to the plate shape, but can be made arbitrary, as long 5 as the vicinity of the side wall inside the reactor body is covered, and the central side thereof is opened. INDUSTRIAL APPLICABILITY [0087] The invention relates to a bubble column type hydrocarbon synthesis reactor 10 including a reactor body containing a slurry having solid catalyst particles suspended in liquid hydrocarbons; a synthesis gas supplying section disposed in a lower portion of the reactor body to supply a synthesis gas including hydrogen and carbon monoxide as main components to the slurry; and a baffle member provided within the reactor body to hinder a downward flow of the slurry. 15 According to the bubble column type hydrocarbon synthesis reactor of the invention, the reaction conversion rate of the synthesis gas which is a raw material can be improved, and a reaction can be efficiently performed throughout the inner space of the reactor.

Claims (8)

1. A bubble column type hydrocarbon synthesis reactor comprising: a reactor body containing a slurry having solid catalyst particles suspended in 5 liquid hydrocarbons; a synthesis gas supplying section disposed in a lower portion of the reactor body to supply a synthesis gas including hydrogen and carbon monoxide as main components to the slurry; and a baffle member provided within the reactor body to hinder a downward flow of 10 the slurry.

2. The bubble column type hydrocarbon synthesis reactor according to claim 1, wherein the baffle member covers a portion of a cross-section of the reactor body. 15

3. The bubble column type hydrocarbon synthesis reactor according to claim 1, wherein the baffle member is provided inside the reactor body so as to block a region near a side wall of the reactor body and open the center of the reactor body and a region 20 in the vicinity of the center.

4. The bubble column type hydrocarbon synthesis reactor according to claim 1, wherein the baffle member is formed with a plurality of through-holes. 25 OSP-27435AU 29

5. The bubble column type hydrocarbon synthesis reactor according to claim 4, wherein the through-holes are sized such that the catalyst particles can pass therethrough, or are sized such that passage of the synthesis gas or bubbles including gas hydrocarbons 5 produced by the reaction of the synthesis gas can be suppressed.

6. The bubble column type hydrocarbon synthesis reactor according to claim 4, wherein the diameter of the through-holes is 10 times to 100 times the mean particle 10 diameter of the catalyst particles.

7. The bubble column type hydrocarbon synthesis reactor according to claim 4, wherein at least a portion of each of the through-holes is formed in a substantially tapered 15 shape of which the cross-sectional area becomes small downward.

8. The bubble column type hydrocarbon synthesis reactor according to claim 1, wherein the baffle member is inclined so as to become lower at the center of the reactor 20 body than at the side wall thereof.