FIELD

[0001] The present specification relates generally to a multi-stage reaction system, specifically a multi-stage reaction system for facilitating a Fischer Tropsch reaction.

INTRODUCTION

[0002] U.S. Patent Application No. 2002/0143075 (Agee et al.) discloses reactor systems, apparatus, and processes which are useful for conducting chemical reactions that may be effected in a three phase slurry system. One particular application converts synthesis gas (syngas) into hydrocarbons. Syngas is comprised of carbon monoxide and hydrogen. In general, a low profile bed reactor is capable of conducting an exothermic catalytic conversion. The reactor may also include a catalyst contained in a moving fluid system which ascends in the reactor in one or more stages. A heat exchanger optionally may be used to remove heat, and water may be removed from the reaction as it proceeds from one stage to another. The reactor is designed in a relatively low profile horizontal design, and is usually more efficient and inexpensive to operate (and build) than taller vertically oriented reactors of the same type.

[0003] U.S. Patent 3,368,875 (Tulleners) discloses an apparatus for the treatment of mineral oils. Mineral oils are hydrogenated (e.g. hydrofined and/ or hydrocracked) in the liquid phase by passing the oil horizontally through a plurality of juxtaposed hydrogenation zones, while effecting a generally countercurrent, horizontal flow of powdered, suspended hydrogenation catalyst serially through the hydrogenation zones. Apparatus is also described, including means for transporting the catalyst serially through the zones and for transferring catalyst free oil from one zone to the next.

[0004] European Patent 1 ,095,697 (Clerici et al.) discloses a horizontal modular reactor for reactions which develop triphasic systems were a gas phase bubbles in a suspension of a solid in a liquid. More specifically, Clerici et al. discloses a horizontal modular reactor for Fischer Tropsch synthesis which is carried out at temperatures ranging from 150 to 400 deg. C and at a pressure of 0.5-20 MPa. SUMMARY

[0005] This summary is intended to introduce the reader to the more detailed description that follows and not to define or limit any claimed subject matter.

[0006] According to one broad aspect there is provided a reaction apparatus for reacting a first fluid with a second fluid. The reaction apparatus comprises at least two reaction cells through which both the first and second fluids are actively transported when the reaction apparatus is in use. Optionally, the reaction apparatus can be configured in a co-current configuration, in which the first and second fluids are transferred through the reaction apparatus in the same direction. Alternatively, the reaction apparatus can be configured in a counter-current configuration, in which the first fluid is transported through the reaction apparatus in a first flow direction and the second fluid is transported through the reaction apparatus in an opposing, second flow direction.

[0007] In some examples the first and second fluids are of sufficiently different densities that the second fluid can be bubbled through the first fluid. In some examples the first fluid is a liquid and the second fluid is a gas. In such examples the gas can be bubbled through the liquid to facilitate a reaction between the gas and the liquid.

[0008] In one example, the reaction apparatus can be configured to facilitate a Fischer Tropsch reaction. In this example the first fluid can be a liquid catalyst slurry, for example a paraffin catalyst slurry, and the second fluid can comprise syngas. The syngas can be reacted with the catalyst by bubbling the syngas into one or more of the liquid catalyst slurry filled reaction cells in the reaction apparatus. In such examples, the liquid catalyst slurry can be pumped through the reaction apparatus in a first, liquid flow direction and, the syngas can be transported through the reactor in either a co-current or counter-current second, gas flow direction.

[0009] According to another broad aspect there is provided a reaction apparatus comprising at least a first reaction cell and a second reaction cell. The first reaction cell includes a first liquid inlet for introducing a liquid into the first reaction cell, and a first liquid outlet fluidly connected to the first liquid inlet for drawing primarily at least a portion of the liquid from the first reaction cell. The first reaction cell further can also include a first gas inlet for introducing a gas into the first reaction cell to be reacted with the liquid in the first reaction cell, and a first gas outlet fluidly connected to the first gas inlet for drawing at least a portion of the gas from the first reaction cell. The second reaction cell comprises a second liquid inlet that is fluidly connected to the first liquid outlet enabling at least a portion of the liquid drawn out of the first reaction cell to flow into the second reaction cell in a liquid flow direction. The second reaction cell also comprises a second liquid outlet fluidly connected to the second fluid inlet for drawing at least a portion of the liquid from the second reaction cell. The second reaction cell also comprises a second gas inlet for introducing the gas into the second reaction cell to be reacted with the liquid in the second reaction cell, and a second gas outlet fluidly connected to the second fluid inlet for drawing at least a portion of the gas from the second reaction cell. The reaction apparatus also includes at least one pump fluidly connected to the first reaction cell for pumping the liquid through the reaction apparatus in the liquid flow direction when the reaction apparatus is in use, and at least one gas processor fluidly connected to at least one of the first gas outlet and the second gas outlet. The gas processor is adapted to process the gas drawn out of a respective one of the first and second reaction cells.

[0010] In some examples, the reaction apparatus is configured as a co-current reaction apparatus in which the second gas inlet is fluidly connected to the first gas outlet enabling at least a portion of the gas drawn out of the first reaction cell to flow in a gas flow direction into the second reaction cell to be reacted with the liquid in the second reaction cell. The at least one gas processor is fluidly connected between the first gas outlet and the second gas inlet and is adapted to process the gas drawn out of the first reaction cell before the gas flows into the second reaction cell.

[0011] In some examples, the first gas outlet is connected to the second gas inlet by a gas recycle conduit and the at least one gas processor is communicably connected to the gas recycle conduit.

[0012] In some examples, the reaction apparatus is configured as a counter- current reaction apparatus in which the first gas inlet is fluidly connected to the second gas outlet enabling a least a portion of the gas drawn out of the second reaction cell to flow in a gas flow direction into the second reaction cell to be reacted with the liquid in the second reaction cell. The at least one gas processor is fluidly connected between the second gas outlet and the first gas inlet and is adapted to process the gas drawn out of the second reaction cell before the gas flows into the first reaction cell [0013] In some examples, the second gas outlet is connected to the first gas inlet by a gas recycle conduit, the at least one gas processor being communicably connected the gas recycle conduit.

[0014] In some examples, the reaction apparatus further comprises a liquid supply conduit fluidly connected to the first reaction cell for supplying the liquid to the first liquid inlet, a liquid removal conduit fluidly connected to second liquid outlet for receiving the liquid drawn from second section reaction cell and a liquid recycle conduit fluidly connecting the liquid removal conduit to the liquid supply conduit for reintroducing at least a portion of the liquid from the liquid removal conduit into the fluid supply conduit upstream of the first liquid inlet.

[0015] In some examples, the reaction apparatus further comprises at least one liquid processor fluidly connected to the liquid recycle conduit connected between the second liquid outlet and the first liquid inlet for processing the portion of liquid that flows from the liquid removal conduit to the liquid supply conduit.

[0016] In some examples, the at least one liquid processor is configured to process the liquid while the reaction apparatus is in use.

[0017] In some examples, the reaction apparatus further comprises a reactor having a shell surrounding at least the first and second reaction cells are contained within a shell of a reactor vessel and the at least one liquid processor is disposed outside of the shell.

[0018] In some examples, the shell defines an interior volume, wherein and the first and second reaction cells are defined by portions of the interior volume separated by at least one baffle extending from the shell.

[0019] In some examples, the first liquid outlet and the second fluid inlet are communicably linked by a fluid flow channel.

[0020] In some examples, the fluid flow channel comprises a gap formed between a free end of the baffle and the vessel reactor shell.

[0021] In some examples, the gas drawn from at least one of the first and second reaction cells comprises unreacted syngas, reaction products and reaction by-products and the gas processor is a separator adapted to substantially separate the unreacted syngas from the reaction products and the reaction by-products. [0022] In some examples, the separator is configured to remove substantially all of the reacted gas and reaction products and the reaction by-products from the reaction apparatus and allow the unreacted syngas to flow into at least one of the first and second gas inlets.

[0023] In some examples, the reaction apparatus further comprises at least one intermediate reaction cell disposed between the first reaction cell and the second reaction cell; the at least one intermediate reaction cell comprises an intermediate liquid inlet fluidly connected to the liquid outlet of the first reaction cell for receiving at least a portion of the liquid drawn from the first reaction cell and an intermediate liquid outlet in fluid communication with the intermediate fluid inlet for drawing at least a portion of the liquid from the intermediate reaction cell, the intermediate liquid outlet fluidly connected to the liquid inlet of the second reaction cell for conveying at least a portion of the liquid removed from the intermediate cell to the second reaction cell. The at least one intermediate reaction cell also comprises an intermediate gas inlet fluidly connected to the gas outlet of one of the first reaction cell and the second reaction cell for receiving at least a portion of the gas drawn from the one of the first reaction cell and the second reaction cell and an intermediate gas outlet fluidly connected to the intermediate gas inlet for drawing at least a portion of the gas from the intermediate reaction cell. The intermediate gas outlet is fluidly connected to the gas inlet of the other of the first reaction cell and the second reaction cell for conveying at least a portion of the gas removed from the one of the first reaction cell and the second reaction cell to the other the first reaction cell and the second reaction cell.

[0024] In some examples, the at least one gas processor comprises at least one gas processor fluidly connected upstream of the intermediate gas inlet and at least one gas processor fluidly connected downstream of the intermediate gas outlet.

[0025] In some examples, the liquid is a catalyst slurry and the gas comprises syngas.

[0026] According to another broad aspect there is disclosed a method of reacting a liquid with a gas, the method comprises:

a) providing at least first and second fluidly connected reaction cells; b) actively transporting the liquid through the first and second reaction cells; c) introducing the gas into one of the first and second reaction cells, reacting the gas with the liquid present in the one of the first and second reaction cells and drawing primarily at least a portion of the gas from the one of the first and second reaction cells;

d) introducing the portion of the gas drawn from the one of the first and second reaction cells into the other of the first and second reaction cells and reacting the gas with the liquid contained in the other of the first and second reaction cells;

e) providing a gas processor in fluid communication with the one of the first and second reaction cells processing the portion of the gas drawn from the one of the first and second reaction cells before introducing the portion of the gas into the other of the first and second reaction cells.

[0027] In some examples the method further comprises providing a liquid recycle conduit fluidly connecting the second reaction cell to the first reaction cell for reintroducing the at least a portion of the liquid drawn from the second reaction cell into the first reaction cell.

[0028] In some examples the method further comprises providing a liquid processor in the liquid recycle conduit and the further step of processing the at least a portion of the liquid removed from the second reaction cell with the liquid processor before it is reintroduced into the first reaction cell.

[0029] In some examples, the step of processing the at least a portion of the liquid removed from the second reaction cell with the liquid processor before it is reintroduced into the first reaction cell is carried out simultaneously with at least steps b) - d).

DRAWINGS

[0030] For a better understanding of the multi-cell reactor described herein and to show more clearly how they may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings which show at least one exemplary embodiment, and in which:

[0031] Figure 1 is a schematic representation of one example of a reaction system; and [0032] Figure 2 is a schematic representation of another example of a reaction system.

[0033] For simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.

DESCRIPTION OF VARIOUS EMBODIMENTS

[0034] Various apparatuses or processes will be described below to provide an example of an embodiment of each claimed invention. No embodiment described below limits any claimed invention and any claimed invention may cover processes or apparatuses that are not described below. The claimed inventions are not limited to apparatuses or processes having all of the features of any one apparatus or process described below or to features common to multiple or all of the apparatuses described below. It is possible that an apparatus or process described below is not an embodiment of any claimed invention. Any invention disclosed in an apparatus or process described below that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors or owners do not intend to abandon, disclaim or dedicate to the public any such invention by its disclosure in this document.

[0035] The following text describes examples of a reaction apparatus for reacting a first fluid with a second fluid. The reaction apparatus includes a multi-stage reactor that includes at least first and second reaction cells, and can comprise one or more intermediate reaction cells disposed therebetween. The first and second fluids are mixed within each reaction cell to facilitate a desired reaction. In examples where the first fluid is denser than the second fluid, the second fluid can be introduced toward the bottom of the reaction cells, bubbled up through the first fluid and then withdrawn from an upper portion of the reaction cells.

[0036] In the present examples the first fluid is a liquid and the second fluid is a gas. Examples of the reaction apparatus described herein can be used to react a variety of different fluids in a variety of different chemical and/or physical reactions. In the present examples, described in detail below, the reaction apparatus is configured to facilitate a Fischer Tropsch reaction, in which the liquid is a catalyst slurry (for example a paraffin catalyst slurry) and the gas comprises syngas.

[0037] Referring to Figures 1 and 2, examples of a reaction apparatus 100 adapted for facilitating the Fischer Tropsch reaction include a multi-cell reactor 102 that has a fluid impermeable outer shell 104 surrounding an internal volume 106. The reactor can be an autoclave or other suitable reactor.

[0038] As used herein, the term syngas refers to the synthesis gas produced by a gasification process and can be a mixture of gaseous compounds including, for example, carbon monoxide, hydrogen, water vapour and carbon dioxide, and may also include smaller or trace amounts of other gases including hydrogen sulphide, carbonyl sulphide, hydrogen cyanide, ammonia and methane.

[0039] In the illustrated examples, the catalyst slurry contains catalyst particles (for example in the form of a fine powder) that are suspended within a wax base. In operation, the wax base can be heated past its melting point so that the catalyst slurry can flow as a liquid and be pumped through the reactor 102.

[0040] The properties of the catalyst (e.g. size, shape, chemical composition, etc.) used the catalyst slurry may be selected based on the desired operating conditions of the reaction apparatus 100 and the nature of the syngas that is to be reacted with the catalyst during use. Examples of catalysts include iron based catalysts, cobalt based catalysts, nickel based catalysts and ruthenium based catalysts. Examples of suitable wax compositions that can serve as the wax base of the first fluid include, for example, paraffin wax and microcrystalline wax.

[0041] The internal volume 106 of the reactor 102 is sub-divided into a plurality of reaction cells 108, 108a-d by a plurality of generally fluid impermeable baffles 1 10 that extend from the shell 104. The plurality of reaction cells 108 includes a first reaction cell, a second reaction cell and two intermediate reaction cells. Each reaction cell 108a- d defines a respective internal cell volume 109a-d. Each baffle 1 10 extends between a proximal end 11 1 a adjacent the shell 104 to a distal or free end 1 1 1 b spaced away from the shell 104.

[0042] The reactor 102 has a liquid supply aperture 154 that is connected to a liquid supply conduit 1 12 for introducing a stream or flow of liquid, for example the catalyst slurry 1 13 into the reactor 102, and a liquid removal aperture 156 that is connected to a liquid removal conduit 1 14 for removing the catalyst slurry 1 13 from the reactor 102. The reactor 102 also includes a gas supply aperture 158 that is connected to a gas supply conduit 1 16 for introducing a stream of fresh syngas 1 15 into the reactor 102, and a gas removal aperture 160 that is connected to a gas removal conduit 1 8 for removing gaseous compounds, including, for example unreacted syngas 1 15, reaction products and gaseous reaction by-products, from the reactor 102.

[0043] Each reaction cell 108a-d in the reactor 102 also includes a liquid inlet 162, for introducing the catalyst slurry 113 into the reaction cells 108a-d, and a liquid outlet 164, in fluid communication with the corresponding liquid inlet 162 for drawing at least a portion of the catalyst slurry 113 (and any entrained reaction products and/or byproducts) from the reaction cells 108a-d.

[0044] In the illustrated examples, the reaction cells 108a-d are fluidly connected in series to each other to provide a continuous liquid flow pathway between the liquid supply aperture 154 and the liquid removal aperture 156, enabling the catalyst slurry 1 3 to be circulated through all of the reaction cells 108a-d as it is pumped through the reactor 102

[0045] Each reaction cell 108a-d also includes a gas inlet 166 for receiving syngas 1 15 and a gas outlet 168, fluidly connected to the gas inlet 166, for drawing at least a portion of the syngas 1 15 (and any entrained reaction products and/or byproducts) from the reaction cells 108a-d. Connecting the gas outlet 168 of a first reaction cell (for example reaction cell 108a) to the gas inlet 166 of a second reaction cell (for example reaction cell 108d) can allow the syngas 1 15 to flow between the connected reaction cells 108a,d. In the example illustrated in Figure 1 , the gas outlet 168 of the first reaction cell 108a is fluidly connected to the gas inlet 166 of the second reaction cell 108d via the intermediate reaction cells 108b, c.

[0046] When the reaction apparatus 100 is in use, the catalyst slurry 1 13 is actively transported into the first reaction cell (for example reaction cell 108a in Figure 1 , and reaction cell 108d in Figure 2). In the illustrated example, the catalyst slurry 113 is actively transported by pumping the catalyst slurry 1 13 through the reactor 102 using a pump 122 that is connected to the liquid supply conduit 1 12. Alternatively, or in addition, the pump 122 can be replaced by, or used in combination with, one or more other suitable fluid moving systems or devices, including, for example, accumulators, compressors and gravity. The pump 122 can be any suitable pump that can be adapted to provide the desired flow rate and operating pressure for the catalyst slurry 1 13. The reaction apparatus 100 may include more than one pump 122 (not shown) connected in parallel to provide a redundant or spare pump 122 as known in the art.

[0047] From reaction cell 108a, the catalyst slurry 1 3 can be pumped through a plurality of fluid flow channels 128 connecting the liquid outlets 164 and liquid inlets 162 of adjacent reaction cells 108a-d. As illustrated in Figure 1 , the catalyst slurry 1 13 can be pumped sequentially, via fluid flow channels 128, into reaction cells 108b, 108c and 08d. From reaction cell 108d, the catalyst slurry 1 13 can exit the reactor 102 via liquid removal aperture 164 and be carried downstream within the liquid removal conduit 114.

[0048] In the illustrated examples, the catalyst slurry 1 13 is denser than the syngas 1 15 so that the catalyst slurry 1 15 that is received in internal cell volume 109a of reaction cell 108a will tend to settle toward the lower portion of the reaction cell 108a, beneath the syngas 1 15 under the influence of gravity.

[0049] The boundary or interface between the catalyst slurry 1 13 and the syngas 115 is represented by interface line 120. In the illustrated example interface line 120 is represented as a generally straight, smooth line, however, it is understood that the actual interface between the catalyst slurry 1 3 and syngas 5 may be uneven and can have irregular features including, for example, a meniscus. The location of the interface line 120 between catalyst slurry 3 and syngas 1 15 can be based on the relative pressures of the catalyst slurry 1 13 and syngas 1 15 and/or other system conditions and reactor 102 design features.

[0050] In the illustrated examples, adjacent reaction cells 108a-d, for example reaction cell 108a and cell 108b, are connected by a fluid flow channels 128. In these examples, the fluid flow channels 128 connecting respective liquid outlets 164 and liquid inlets 162 of adjacent reaction cells 108a-d are formed by the gaps or spaces defined between the free ends 1 1 1 b of the baffles 1 10 and the shell 104 of the reactor 102.

[0051] The size and shape of the baffles 1 10 can be selected so that the fluid flow channels 128 (i.e. the gaps between the free ends 1 1 1 b and the shell 104) are located below the interface line 120 between the catalyst slurry 113 and syngas 115 in each reaction cell 108a-d. Configuring the reactor 102 and baffles 1 0 so that the fluid flow channels 128 are located below the interface lines 120 of each reaction cell 108a-d can enable the denser, catalyst slurry 1 13 to flow through the fluid flow channels 128 while inhibiting the transfer of the syngas 1 15 between adjacent reaction cells 108a-d through the fluid flow channels 128.

[0052] In the illustrated example, the baffles 1 10 are the same size and the fluid flow channels 128 between adjacent reaction cells 108a-d are the same size throughout the reactor 102. In other examples, the baffles 1 10 may be different sizes so that the size and location of the fluid flow channels 128 can be different at different locations in the reactor 102. For example, the fluid flow channel 12 between reaction cells 108a and 108b may be larger, or positioned higher, than the fluid flow channel 1 12 between reaction cells 108c and 108d.

[0053] In other examples, the baffles 1 10 can be extended across the entire the width of the reactor 102 such that there is no gap between a free end 1 1 1b of a baffle 1 10 and the shell 104 of the reactor 102. In these examples, each baffle 1 10 can be provided with one or more apertures or openings (not shown) extending through the baffles 1 10 and allowing a fluid on a first side of a baffle 1 0 to flow through to a second side of the baffle 1 10 (for example from one reaction cell to another, adjacent reaction cell). In these examples, fluid flow channels 128 may be defined by one or more aperture(s) in each baffle 1 10.

[0054] Optionally, baffles 110 which do not extend across the entire reactor 102, thereby forming fluid flow channels 128 comprising gaps between the free ends 1 1 1b of the baffles 1 10 and the shell 104 as illustrated, may also comprise one or more apertures (not shown) as described above. In such examples, the fluid flow channels 128 can include both the gap between the free ends 1 1 1 b and the shell 104, and the apertures, and any combination thereof.

[0055] In other examples, the multi-cell reactor 102 may comprise a plurality of separate reaction vessels (not shown), each vessel containing one or more reaction cells. In such examples, at least a portion of the fluid flow channels 128 may be suitable, external fluid conduits that extend between two or more of the separate reaction vessels. Examples of such fluid conduits include pipes and hoses.

[0056] In some examples, the reactor 102 may be connected to multiple liquid supply conduits 112 (for example at least one liquid supply conduit 1 12 connected to the first fluid inlet 162 of each reaction cell 108, not shown) and additionally, or alternatively, to multiple liquid removal conduits 114.

[0057] Referring to Figure 1 , syngas 115 introduced into the reactor 102 flows generally from the gas inlet 158, connected to the gas supply conduit 116, to the gas outlet 160, connected to the gas removal conduit 1 8. In this example, the syngas 115 is less dense than the catalyst slurry 113 and can be bubbled through the catalyst slurry 113 to promote a chemical reaction between the catalyst slurry 113 and syngas 115. To facilitate this syngas 115 flow, the gas inlet 158,166, in this example a sparger 124, is configured to bubble the syngas 115 (e.g. a gas) into the reaction cells 108a-d containing the catalyst slurry 113 (e.g. a liquid).

[0058] In the illustrated examples, the sparger 24 is located toward the bottom of the reaction cell 108a, which can increase the volume of catalyst slurry 113 the injected syngas 115 can bubble through before reaching the interface line 120. Optionally, the sparger 124 can be positioned above the bottom of the reaction cell 108a (i.e. not in contact with shell 104), which can reduce the likelihood that the sparger 124 will be fouled or otherwise affected by particulate, sediment or other compounds in the catalyst slurry 113. In other examples, the sparger 124 can be located in any desired position within the reaction cell 108a, including, for example, a sidewall, in the centre of the cell and toward the top of the cell.

[0059] In other examples, the syngas 115 delivered by the gas supply conduit 116 can be introduced into the reactor 102 using any suitable means or apparatus in alternative or in addition to the sparger 124, including, for example, a nozzle, a jet, an orifice plate and a valve.

[0060] In the example illustrated in Figure 1 , after exiting the sparger 124, the syngas 1 5 bubbles upward, toward an upper portion of the reaction cell 108a. In the upper portion of the reaction cell 108a the syngas 115 is collected and exits the reaction cell 108a, through a gas outlet 168, and is routed through a gas recycle conduit 126.

The gas recycle conduit 126 from reaction cell 108a is connected to the gas inlet 166, i.e. sparger 24, of at least one other reaction cell 108. In the co-current example illustrated in Figure 1 , the plurality of reaction cells 108a-d are connected in series, such that the gas outlet 168 of reaction cell 108a is connected to the gas inlet 168, i.e. sparger 124 of reaction cell 108b by the gas recycle conduit 126. Similarly, the outlet

168 of reaction cell 108b is connected to the sparger 124 of reaction cell 108c and the outlet 168 of from reaction cell 108c is connected to the sparger 124 of reaction cell 108d. Syngas 1 15 collected in reaction cell 108d can be removed from the reactor 102 via gas removal conduit 1 18.

[0061] The gas recycle conduits 126 can include any suitable type of fluid handling conduit, including, for example, pipes, ducts and hoses. In some examples the gas recycling counduits 126 may run outside the shell 104 of the reactor 102. In other examples the gas recycling streams 126 (i.e. the conduits carrying the recycled syngas 1 5) may run at least partially within the reactor shell 104.

[0062] In this example, the catalyst slurry 1 13 and syngas 15 flow through the reactor 102 in generally the same direction. Both the liquid and gas flow directions are generally from right to left as illustrated in Figure 1 . In this configuration, the catalyst slurry 1 13 and syngas 1 5 pass through the reaction cells 108a-d in the same order, namely from reaction cell 108a to reaction cell 108d. A reactor 102 configured to operate in this manner may be described as having co-current gas and liquid flows.

[0063] In a co-current reactor 102, as illustrated in Figure 1 , a fresh supply of syngas 1 15 is reacted with a fresh supply of catalyst slurry 1 13, which may produce a relatively high reaction rate in the first reaction cell 108a, and the reaction rate may decrease in subsequent reaction cells 108b-d which are filled with progressively more "used" catalyst slurry 1 13.

[0064] Referring to Figure 2, another example of a reaction apparatus 100 is illustrated in a counter-current configuration. In this example, the syngas 115 is less dense than the catalyst slurry 13 and can be bubbled through the catalyst slurry 1 13 to promote a chemical reaction between the catalyst slurry 1 13 and syngas 1 15. To facilitate this example, the gas supply conduit 116 is connected to gas inlet 158, 166, in this example a sparger 124, that is configured to introduce the syngas 1 15 into the catalyst slurry 113. In this example, the frist reaction cell to which the gas supply conduit 1 16 is connected is reaction cell 108d, instead of reaction cell 108a. The sparger 124 used in this example can be the same as the sparger 124 (and any alternative thereto) described above with reference to Figure 1.

[0065] As illustrated in Figure 2, after exiting the sparger 124, the syngas 15 bubbles upward, toward an upper portion of the reaction cell 108d. In the upper portion of the reaction cell 108d the syngas 1 15 is collected and exits the reaction cell 108d, through a gas outlet 168, as a gas flow that travels within gas recycle conduit 126. The gas outlet 168 of reaction cell 108d is connected to the gas inlet 166, i.e. sparger 124, of at least one other reaction cell 108. In the illustrated example, the plurality of reaction cells 108a-d are connected in series, such that the gas outlet 168 of reaction cell 108d is connected to the sparger 124 of reaction cell 108c, the gas outlet 168 of reaction cell 108c is connected to the sparger 124 of reaction cell 108b and the gas outlet 168 of reaction cell 108b is connected to the sparger 124 of reaction cell 108a. Syngas 115 collected in reaction cell 108a can be removed from the reactor 102 via gas removal conduit 118.

[0066] In this counter-current example, the catalyst slurry 113 and syngas 115 flow through the reactor 102 in generally opposing directions. The catalyst slurry 113 flows in a liquid flow direction, generally from right to left as illustrated in Figure 2, and the syngas 115 flows in a gas flow direction, generally from left to right as illustrated in Figure 2. In this configuration, the catalyst slurry 113 passes through the reaction cells 108a-d in a first order, namely from reaction cell 108a to reaction cell 108d, while the syngas 115 passes through the reaction cells 108a-d in a second, opposite order, namely from reaction cell 108d to reaction cell 108a. A reactor 102 configured to operate in this manner may be described as having counter-current fluid flows or fluid pathways, because the catalyst slurry 113 and syngas 115 move in generally the opposite directions through the reactor 02.

[0067] In a counter-current reactor 102, as illustrated in Figure 2, the fresh supply of syngas (from gas supply conduit 116) is reacted with the most "used" catalyst slurry 113 in reaction cell 108d producing a first reaction rate. The reaction rate in the remaining reaction cells 108c-a between a progressively more "used" syngas stream 115 (as the amount of unreacted syngas in the gas streams is decreased by passing through each preceding reaction cells) and a progressively "fresher" catalyst slurry 113 (i.e. slurry that has been exposed to a smaller amount of syngas) may remain generally the same as the reaction rate in the first reaction cell 108d, or may gradually increase or decrease. Under certain operating conditions, a counter-current reactor 102 may provide a reactor 102 in which the reaction rate remains generally constant within each of the plurality of reaction cells 108a-d.

[0068] As used herein, the flow direction can be broadly understood as the order in which a fluid passes through the plurality of reaction cells 108. For example, the liquid and gas flows can be in generally the same direction (a co-current configuration) if both fluids move, for example, from reaction cell 108a to reaction cell 108d, despite the fact that the catalyst slurry 113 moves generally horizontally through each cell 108a-d (under the baffles 110) and the syngas 115 moves generally vertically through each cell 108a-d (bubbled up from spargers 124 and routed through gas recycle streams 126).

[0069] In some examples, the temperature of the catalyst slurry 113 can be controlled throughout the operation of the reaction apparatus 100 so that the catalyst slurry 113 can remain a liquid having desired properties (e.g. viscosity, density, etc.). In some examples the operating temperature of the reaction apparatus 100 may be between 100 and 1000 degrees Celsius. In other examples the operating temperature of the reaction apparatus 100 may be between 200 and 500 degrees Celsius. In the illustrated example, the operating temperature of the reaction apparatus 100 can be between 220 and 250 degrees Celsius and can be approximately 230 degrees Celsius. The operating temperature of any given the reaction apparatus 100 can be selected based on the nature catalyst slurry used and/or of the reaction contained therein.

[0070] To modify and/or control the temperature of the catalyst slurry 13 when the reactor 102 is in use, the reactor 102 can include one or more heat exchangers 130. The heat exchangers 30 can be any suitable type of heat exchanger that can operate in the expected operating conditions of a given reactor 102. In some examples the reaction within the reactor 102 may be an endothermic reaction and the heat exchangers 130 may be configured to provide heat to the reactor 102. In other examples, the reaction within the reactor 102 may be an exothermic reaction and the heat exchangers 130 may be configured to remove heat from the reactor 02.

[0071] In the illustrated examples, each reaction cell 108a-d includes a separate heat exchanger 130 that can be operable to regulate the temperature of the catalyst slurry 113 within the respective reaction cell 108a-d. Optionally, the reactor 102 can be operated such that the catalyst slurry 113 temperature in each reaction cell 108a-d is the same, or, the reactor 102 can be operated such that the catalyst slurry 113 can be at a different temperature in each reaction cell 108a-d.

[0072] In other examples, the reactor 102 can be configured such that each reaction cell 108 does not have an individual heat exchanger 130 and the reactor 102 can include one or more heat exchangers 130 that each extend through one or more reaction cells 108. For example, a reactor 102 could include a single heat exchanger (or optionally more than one heat exchanger) that extends from reaction cell 108a to reaction cell 108d.

[0073] The reaction rate (between the syngas 1 15 and the catalyst slurry 1 13) in the reactor 102 can be affected by the relative partial pressures of unreacted syngas and active catalyst contained within a particular reaction cell 108a-d. Increasing the reaction rate, and/or inhibiting a decrease in reaction rate as the syngas moves through the reaction cells 108a-d of the reactor 102, may improve reactor efficiency. During operation of the reactor 102, for example as the syngas introduced into reaction cell 108a reacts with the catalyst slurry in reaction cell 108a, the partial pressure of the syngas may decrease, which may reduce the reaction rate. Alternatively, or in addition, the accumulation of Fischer-Tropsch reaction by-products may have unwanted or adverse affects on the catalyst in the reactor 102. For example, water can deactivate catalyst particles in the catalyst slurry 1 13, which may reduce the amount of active catalyst available to react with the syngas 115.

[0074] In the illustrated examples, the reaction apparatus 100 includes gas treatment means or processors, for example separators 132, in communication with the gas recycle conduits 126 and the gas removal conduit 1 18.

[0075] The gas processors can be configured to treat or process the syngas 1 15 exiting a first reaction cell before it is re-introduced into a subsequent reaction cell. The separators 132 can be any suitable separator that is configured to separate unreacted syngas 1 15 from reaction products and by-products, including, for example, a condensate separator.

[0076] In the illustrated examples, fresh syngas 115 is introduced into a first reaction cell (108a in Figure 1 and 108d in Figure 2) from the gas supply conduit 16.

As the syngas 1 15 bubbles up through the reaction cell 108a/d, it reacts with the catalyst particles suspended in the catalyst slurry 1 13 to produce desired hydrocarbon products (reaction products), as well as undesired reaction by-products, including water and carbon dioxide. At least a portion of the reaction products and unwanted reaction by-products may become entrained in the syngas 1 15 as it exits the reaction cell

108a/d. For the purposes of this description, a gas flow containing syngas 1 15 that is to be reacted is referred to as the gas flow or syngas flow even though it can contain measurable amounts of other compounds, including, for example, reaction products, reaction by- products and other contaminants or impurities. Similarly, the term liquid flow or catalyst slurry flow is used to describe the liquid material flowing through the reactor 102, which includes the catalyst slurry 1 13 supplied into the first reaction cell 108a/d, as well as measurable amounts of other compounds, including, for example, liquid reaction products, liquid reaction by-products and other contaminants or impurities.

[0077] As the gas flow (which may now contain syngas, reaction products and reaction by-products) exits the first reaction cell 108a/d via gas recycle conduits 126 it is passed through the separator 132. In the separator 132, the unreacted syngas can be substantially separated from the reaction products and by-products. The unreacted syngas 1 15 can then continue along the gas recycle conduit 126 to enter the next reaction cell 108b/c, while the reaction products and unwanted by-products can be separated and transported away as a separator output stream 34 for further processing as desired. In some examples, additional fresh syngas 1 15 can be introduced into some or all of the gas recycle conduits 126, which can further increase the concentration of syngas 1 15 entering the reaction cells 108a-d.

[0078] The syngas 115 flowing through the gas recycle conduits 126 is processed in the manner described above after exiting each reaction cell 108a-d. Removing or separating the reaction products and by-products from the syngas 1 15 after each step in the reaction process (i.e. after passing through each reaction cell 108a-d) may reduce the amounts of reaction products and by-products that are accumulated within or carried through the reactor 102 by the syngas 1 15, and may inhibit the decrease of the partial pressure of unreacted syngas in the gas stream as the syngas 1 15 moves through each cell 108. Removing reaction by-products after each reaction cell 108 may also reduce the accumulation of unwanted by-products, for example water, within the reactor 102. Reducing the accumulation of by-products in the reactor 102 may enable the reactor 102 to be configured to operate with a smaller liquid flow capacity compared to a similar reactor in which reaction by-products in the gas stream are not removed after one or more reaction cells 108. This may enable the multi-cell reactor 102 to be smaller than a conventional single cell reactor adapted to process a comparable quantity of syngas. Reducing the size of a reactor may, in some examples, reduce the manufacturing costs of the reactor and simplify transportation of the reactor to an installation site.

[0079] When the syngas 1 15 exits the last reaction cell 108d/a, the gas removal conduit 118 can also include a separator 132 for separating reaction products and by- products from the syngas stream. In some examples, as illustrated in Figures 1 and 2, the reaction conditions can be selected by a user such that substantially all of the syngas in the gas stream is reacted or consumed as the syngas 115 reacts with the catalyst slurry 113 as it passes through the reaction cells 108a-d. In such examples, the reaction apparatus 100 may not include a syngas overall recycle circuit (not shown) and any residual tail gases or small amounts of unreacted syngas can be disposed of, or sent for further processing, via tail gas stream 136.

[0080] In some examples tail gas stream 136 can be integral with the separator output stream 134 of the separator 132 in the gas removal conduit 1 18. Operating the reaction apparatus 100 without a syngas overall recycle circuit can reduce the required volumetric flow rate capacity of the gas conduits 1 16, 1 18, 126 because the gas flow conduits only need to convey fresh syngas and do not need to accommodate a volume of recycled syngas that is being passed through the reactor 102 for a second (or higher) pass. Reducing the required syngas flow rate may reduce the required reactor 102 size (e.g. a smaller shell 104 cross-sectional area may be sufficient to accommodate a smaller volume of syngas 1 15) and operating costs (e.g. less syngas 1 15 needs to be compressed and transported).

[0081 ] In other examples, the syngas flowing through the gas removal conduit 1 18 can include a practically useable or significant amount of unreacted syngas. In such examples, the reaction apparatus 100 can include an overall recycle circuit (not shown) for combining unreacted syngas from the gas removal conduit 118 with the gas supply conduit 1 16, or other suitable fluid stream (such as one or more of the gas recycle conduits 126).

[0082] In the illustrated examples the reaction apparatus 100 includes a plurality of separators 132 disposed so that each gas recycle conduit 126 includes one separator 132. In other examples, one or more gas recycle conduits 126 can be in communication with the same separator 132, for example the reaction apparatus 100 can include a single separator 132 connected to all of the gas recycle conduits 126. In other examples, one or more of the gas recycle streams 126 can include more than one separator 132, for example a first separator 132 to extract water and a second separator 132 to extract desired reaction products.

[0083] Reaction products and reaction by-products can also become mixed with or entrained within the catalyst slurry 1 13 as it flows through the reactor 102. In the illustrated examples desired hydrocarbon products and liquid water (amongst other compounds) can become entrained in the catalyst slurry such that the water and hydrocarbons flow along with the catalyst slurry 113 between adjacent reaction cells 108a-d and can removed from the reactor 102 via the liquid removal conduit 114 along with the catalyst slurry 113. The liquid removal conduit 114 can include a liquid processor, for example a separator 138 for separating the reaction products and/or reaction by-products from the catalyst slurry 113.

[0084] The liquid separator 138 can be any type of suitable separator apparatus that can be configured to separate the reaction products and/or by-products from the catalyst slurry 113. For example, the separator 138 illustrated in Figures 1 and 2 can be operable to separate hydrocarbon reaction products from the catalyst slurry and can be, for example, a condensate separator, a filter, an evaporator, an electrofilter, a chemical separator or any combination thereof. Separated compounds (including reaction products and/or by-products) can exit the liquid separator 138 as a liquid separator output stream via output conduit 140 and can be sent for further processing and/or storage as desired. In some examples, the first fluid separator 138 can have more than one liquid separator output conduits 140 which may enable the output from the separator 138 to be diverted to more than one downstream location, based on user requirements. For example, outputs from the first fluid separator 138 can be divided based on flow rate, chemical composition, downstream processing requirements, any other user defined requirement and any combination thereof.

[0085] In the illustrated examples, the catalyst slurry 113 exits the first liquid separator 138 and enters a liquid recycle conduit 142. The catalyst slurry 113 in the liquid recycle conduit 142 can be conveyed through the liquid recycle conduit 142 by any suitable conveying means 144, including, for example a pump 144 if the catalyst slurry 113 is a liquid or a compressor in examples where the catalyst fluid is a gas. Catalyst slurry 113 exiting the liquid recycle conduit 142 can be combined with the liquid supply conduit 12 upstream of the liquid inlet aperture 154 of the reactor 102 so that the recycled catalyst slurry 113 (i.e. fluid from the liquid recycle conduit 142) can be reintroduced into, and re-circulated through, the reactor 102.

[0086] In some examples, the recapture or recycle rate of the catalyst slurry 113 can be high enough that the reaction apparatus 100 can be operated with the catalyst slurry 113 flowing in a closed system (i.e. without the introduction of additional or "fresh" catalyst slurry into the reactor 102). In other examples, as illustrated in Figures 1 and 2, the reaction apparatus 100 can include a fresh liquid supply conduit 148 that can introduce a required amount of fresh catalyst slurry 113 during operation of the reaction apparatus 100 to account for any catalyst slurry 113 that is lost or consumed during the reaction. The fresh liquid supply conduit 148 can also be used to introduce catalyst slurry 113 into the reactor 102 prior to the initial start-up of the reaction apparatus 100 and/or after any reactor 102 shut downs (e.g. for maintenance and/or production scheduling reasons).

[0087] After passing through the liquid separator 138 the catalyst slurry 13 may still contain some undesirable contaminants or reaction by-products. For example, the catalyst slurry 113 flowing in the liquid recycle conduit 142 can include some catalyst particles that have been fouled and/or deactivated by reacting with water molecules that were present in the reactor 102. Catalyst slurry 13 containing fouled and/or deactivated catalyst particles may not react as efficiently with the syngas 115 as clean or fresh catalyst slurry, which may inhibit reaction apparatus 100 efficiency. Optionally (as indicated by the use of dotted lines), the liquid recycle conduit 142 can contain a liquid processor 146 for processing and/or reconditioning the catalyst slurry 113. In the illustrated examples, the liquid processor 146 is a catalyst regenerator 147 that is operable to regenerate or reactivate the catalyst particles in the catalyst slurry 113 by, for example, removing water molecules from the catalyst slurry 3.

[0088] Passing the catalyst slurry 3 through the catalyst regenerator 147 may reduce the accumulation of water and other contaminants in the catalyst slurry 113 over successive cycles (i.e. passages through the reactor 02) and may extend the useful or productive life of the catalyst. Providing the catalyst regenerator 147 in the external, liquid recycle conduit 142 can allow at least a portion of the catalyst slurry 1 3 to be regenerated on each cycle through the reactor 102 and can enable the catalyst slurry 113 to be treated while the reactor 102 is in use and without requiring the complete shut down of the reactor 102. Providing a means for processing the catalyst slurry 113 while the reactor 102 is online (i.e. in use) may increase the amount of time between the reactor 102 shut-downs, which are required in order to remove and process the catalyst slurry from some traditional, single-stage, vertical reactors.

[0089] The conditions in the liquid recycle conduit 142 can be adjusted using any suitable mechanism (for example orifice plates, pressure regulators, valves, heat exchangers, etc. not shown) to enhance the operation of the catalyst regenerator 142 without affecting the operating conditions of reactor 102.

[0090] In other examples, the reaction apparatus 100 may not include a liquid recycle conduit 142, used catalyst slurry 113 exiting the reactor 102 may be disposed of or otherwise treated and an ongoing supply of fresh catalyst slurry can be supplied, as needed, via the fresh liquid supply conduit 148 when the reaction apparatus 100 is in operation.

[0091] In the illustrated example, the multi-cell reactor vessel 102 is a generally cylindrical single vessel, arranged substantially horizontally, that contains a plurality of internal sub-compartments or chambers that form the reaction cells 108a-d. While the reactors 102 illustrated include four reaction cells 180a-d, it is understood that in other examples the plurality of reaction cells 108 in a reactor 102 may include fewer than four reaction cells or more than four reaction cells.

[0092] In other examples, the reactor 02 may be of any suitable cross-sectional shape (i.e. rectangular, polygonal) and may be of any suitable, desired size. The cross- sectional area of the reactor 102 can be selected based on the desired capacity and flow-rate requirements of the reactor 102. The shell 104, baffles 10 and any other components of the reaction apparatus 100 and reactor 102 can be formed from any material having the suitable mechanical properties to withstand the expected operating temperatures and pressures of the reactor 102, including, for example, steel. In some examples the reactor 102 operating pressure can be between 10 and 30 bar, and can be approximately 18 bar. Operating the reactor 102 as a high-pressure, horizontal reactor may enable the reactor 102 to be smaller than a traditional vertical slurry bubble column reactor configured to process comparable quantities of syngas. A smaller multi- cell reactor may be cheaper to manufacture and transport than a conventional bubble column reactor.

[0093] In the illustrated examples the reactor 102 is configured to facilitate a

Fisher Tropsch reaction, in which the catalyst slurry 113 is reacted with the syngas 115.

In other examples, other desired first and second fluids that a user wishes to mix or react within the reactor can be used in place of the catalyst slurry 113 and syngas 115.

Optionally, the first fluid can comprise solid catalyst particles that have been fluidized or are otherwise capable of "flowing" through the reactor 102 (e.g. small, gravel-like particles may be able to sufficiently "flow" through a reactor 102 that is disposed on an incline in the absence of a wax base). In some examples the firs fluid can be a particulate material moved through the reactor 102 using a positive conveyance mechanism, such as, for example, an auger or a conveyor system.

[0094] What has been described above has been intended to be illustrative of the invention and non-limiting and it will be understood by persons skilled in the art that other variants and modifications may be made without departing from the scope of the invention as defined in the claims appended hereto.