KR102858818B1 - Reactor with micro-channel - Google Patents

Abstract

According to one embodiment of the present invention, a microchannel reactor is provided, comprising: a plurality of catalyst layers that promote a Fischer-Tropsch reaction; a plurality of reaction channels extending in one direction defined by the plurality of catalyst layers; and at least one sub-channel provided in the middle of the catalyst layers to connect adjacent reaction channels, wherein a reactant of a Fischer-Tropsch reaction moves through the reaction channels, and when a portion of the reaction channels is blocked, the reactant moves to an adjacent reaction channel through the sub-channel. According to the present application, even if coking or sintering occurs within the reactor, the reaction process can be stably continued.

Description

Reactor with micro-channel

The present invention relates to a microchannel reactor capable of preventing clogging within the reactor by improving the flow of materials within the reactor.

The Fischer-Tropach (F-T) reaction is a reaction that produces synthetic oil from synthesis gas (CO+H2), and synthesis gas is mainly produced by coal gasification or natural gas reforming.

CO + 2H ₂ → C _n H _2n + H ₂ O, △H ₂₉₈ = -160 kJ/mol

As shown in the equation above, the Fischer-Tropsch reaction is a strongly exothermic reaction, making heat of reaction control a critical factor. Failure to control the heat of reaction not only leads to a rapid rise in reactor temperature, which poses serious safety risks to the reaction process, but also a sharp decline in C5+ selectivity. Therefore, an effective solution is needed to control this phenomenon.

Typically, microchannel reactors are structured with stacked plates, with the catalyst layer having refrigerant layers above and below it, and the catalyst layer having a thickness of several millimeters. Compared to traditional tube-shaped fixed-bed catalytic reactors, microchannel reactors have a heat transfer surface area 10 to 100 times larger, offering superior heat exchange performance and attracting attention as reactors for either highly exothermic or endothermic reactions. Currently, microchannel reactors are being commercialized as compact reactors for the highly exothermic Fischer-Tropsch reaction.

Microchannel reactors, as described above, offer the advantage of superior heat exchange performance. However, they can also pose safety risks, such as coking, where carbon accumulates on the catalyst surface during the reaction, reducing reactivity. Furthermore, sintering, where nanoparticles clump together, can also lead to increased reactor pressure. Therefore, an improved structure is needed to prevent coking and sintering in microchannel reactors.

One object of the present invention is to provide a reactor capable of stably performing a reaction process even when coking and sintering phenomena occur by improving the shape of a reaction path in a microchannel reactor.

According to one embodiment of the present invention, a microchannel reactor is provided, comprising: a plurality of catalyst layers that promote a Fischer-Tropsch reaction; a plurality of reaction channels extending in one direction defined by the plurality of catalyst layers; and at least one sub-channel provided in the middle of the catalyst layers to connect adjacent reaction channels, wherein a reactant of a Fischer-Tropsch reaction moves through the reaction channel, and when a portion of the reaction channel is blocked, the reactant moves to the adjacent reaction channel through the sub-channel.

According to one embodiment of the present invention, a microchannel reactor is provided in which the sub-movement paths are provided in a number of 2 to 10 for each of the catalyst layers.

According to one embodiment of the present invention, a microchannel reactor is provided, further comprising a refrigerant layer provided adjacent to the catalyst layer.

According to one embodiment of the present invention, a microchannel reactor is provided, wherein the reaction path has a diameter of 1 mm to 100 mm.

According to one embodiment of the present invention, a microchannel reactor is provided, wherein the sub-channel has a width of 1 mm to 10 mm.

According to the present invention, by improving the shape of the reaction path in a microchannel reactor, a reaction process can be stably performed even when coking and sintering phenomena occur.

In addition, the flow of reactants and products inside the reactor is excellent, so the efficiency of the microchannel reactor can be improved.

FIG. 1 is a perspective view and a cross-sectional view of a microchannel reactor according to one embodiment of the present invention.
Figure 2a shows the results of analyzing the Fischer-Tropsch reaction efficiency at steady state without blockage in the reactors of the examples and comparative examples. Figure 2b shows the results of analyzing the flow velocity within the flow path at steady state without blockage in the reactors of the examples and comparative examples. Figure 2c shows the results of analyzing the temperature distribution within the flow path at steady state without blockage in the reactors of the examples and comparative examples.
Figure 3a shows the results of analyzing the Fischer-Tropsch reaction efficiency when blockage occurred in the reactors of the examples and comparative examples. Figure 3b shows the results of analyzing the flow velocity within the flow path when blockage occurred in the reactors of the examples and comparative examples. Figure 3c shows the results of analyzing the temperature distribution within the flow path when blockage occurred in the reactors of the examples and comparative examples.
Figure 4a shows the results of analyzing the Fischer-Tropsch reaction efficiency when multiple channels were blocked in the reactors of the examples and comparative examples. Figure 4b shows the results of analyzing the flow velocity within the channels when multiple channels were blocked in the reactors of the examples and comparative examples. Figure 4c shows the results of analyzing the temperature distribution within the channels when multiple channels were blocked in the reactors of the examples and comparative examples.
Figure 5a shows the results of analyzing the Fischer-Tropsch reaction efficiency when multiple channels were blocked in the reactors of the examples and comparative examples. Figure 5b shows the results of analyzing the flow velocity within the channels when multiple channels were blocked in the reactor of the examples. Figure 5c shows the results of analyzing the temperature distribution within the channels when multiple channels were blocked in the reactor of the examples.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings and the contents described in the attached drawings, but the present invention is not limited or restricted by the embodiments.

The terminology used herein is for the purpose of describing embodiments only and is not intended to limit the present invention. In this specification, the singular also includes the plural unless the context clearly dictates otherwise. As used herein, the terms "comprises" and/or "comprising" do not exclude the presence or addition of one or more other components, steps, operations, and/or elements.

The terms “embodiment,” “example,” “aspect,” “example,” and the like as used herein are not to be construed as implying that any aspect or design described is better or advantageous over other aspects or designs.

The terms used in the following description have been selected as common and universal in the relevant technical fields. However, other terms may be used depending on technological developments and/or changes, customs, and the preferences of technicians. Therefore, the terms used in the following description should not be construed as limiting the technical concepts, but rather as exemplary terms used to describe the embodiments.

Additionally, in certain cases, the applicant may arbitrarily select terms, in which case their detailed meanings will be described in the relevant description. Therefore, the terms used in the following description should be understood not simply as names, but based on their inherent meaning and the overall context of the specification.

While terms like "first" and "second" can be used to describe various components, the components themselves are not limited by these terms. These terms are used solely to distinguish one component from another.

Additionally, when a part such as a film, layer, area, or component request is said to be "on top" or "over" another part, this includes not only cases where it is directly on top of the other part, but also cases where there are other films, layers, areas, components, etc. intervening therebetween.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in the same sense as commonly understood by those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries shall not be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

Meanwhile, when describing the present invention, if a detailed description of a related known function or configuration is judged to unnecessarily obscure the gist of the present invention, such detailed description will be omitted. Furthermore, the terminology used in this specification is intended to appropriately express embodiments of the present invention and may vary depending on the intent of the user or operator, or the practices of the field to which the present invention pertains. Therefore, the definitions of these terms should be based on the contents throughout this specification.

A microchannel reactor according to one embodiment of the present invention includes a sub-channel connecting adjacent reaction channels, so that a process can be stably continued even if coking or sintering occurs in a part of the reaction channel.

FIG. 1 is a perspective view and a cross-sectional view of a microchannel reactor according to one embodiment of the present invention.

Referring to FIG. 1, a microchannel reactor according to one embodiment of the present invention comprises: a plurality of catalyst layers (100) that promote a Fischer-Tropsch reaction; a plurality of reaction channels (110) extending in one direction defined by the plurality of catalyst layers (100); and at least one sub-channel (120) provided in the middle of the catalyst layers (100) to connect adjacent reaction channels (110), wherein a reactant of a Fischer-Tropsch reaction moves through the reaction channel (110), and when a portion of the reaction channel (110) is blocked, the reactant is configured to move to the adjacent reaction channel (110) through the sub-channel (120).

The catalyst layer (100) includes a catalyst for promoting the Fischer-Tropsch reaction, and refers to a place where reactants are supplied and the reaction occurs. A catalyst capable of promoting the above-described Fischer-Tropsch reaction is provided in the catalyst layer (100). The catalyst lowers the activation energy of the Fischer-Tropsch reaction so that the reaction can occur more quickly. For this purpose, an iron-based catalyst or a cobalt-based catalyst may be provided in the catalyst layer (100). However, the types of catalysts described above are merely exemplary, and the catalyst layer (100) may be composed of a material having excellent activity for the Fischer-Tropsch reaction, if necessary. In addition, the catalyst may be in various forms, such as a porous catalyst, a molecular sieve, a monolithic catalyst, or a supported catalyst.

There is no limitation on the form in which the catalyst is provided to the catalyst layer (100). For example, the catalyst may be provided in various forms, such as by loading a particulate catalyst to form the catalyst layer (100), or by coating the inner wall of the reactor with the catalyst.

The catalyst layer (100) defines a reaction path (110) in which a catalyst is provided. Specifically, an empty space surrounded by the catalyst layer (100) through which reactants can pass and react can be defined as the reaction path (110). Within the reaction path (110), reactants can be introduced and converted into reaction products through an exothermic reaction. That is, the reaction path (110) can be provided in the form of a pipe through which reactants and reaction products can flow, and the catalyst can be provided in the form of being coated on the wall surface of the pipe (reaction path (110)) or filled on the wall surface.

The reaction path (110) has a shape that extends in one direction. Here, the shape that extends in one direction means that the overall shape of the reaction path (110) shows a shape that extends long in one direction. In other words, the reaction path (110) does not necessarily have to be a straight line, and may have a curved shape, and one or more corners may be provided in the reaction path (110). There is no limitation on the shape of the reaction path (110) as long as it has a structure in which the reactants flow into the reaction path (110) and meet the catalyst layer (100) and thus the Fischer-Tropsch reaction can occur as the reactants flow.

A plurality of reaction channels (110) are provided. For example, a plurality of reaction channels (110) may be provided in parallel. The plurality of reaction channels (110) are provided spaced apart from each other. In this case, the catalyst layer (100) may be composed of a catalyst coating on the surface and a buffer layer provided under the catalyst coating. Accordingly, the catalyst layer (100) defining the reaction channel may be composed of a buffer layer and a catalyst coating provided on both sides of the buffer layer.

The reaction path (110) may have a diameter of 1 mm to 100 mm. Therefore, the reactor according to one embodiment of the present invention may be a microchannel reactor. A reactor using microchannels (hereinafter referred to as a microchannel reactor) is a compact reactor that is very effective in performing chemical reactions such as the Fischer-Tropsch reaction, having a structure that combines a plurality of unit reactors equipped with microchannels. In particular, compared to a conventional fixed-bed reactor, it has a structure that allows smooth material and heat exchange to maximize the performance of the catalyst, and therefore is evaluated to be effective in a hydrogen supply device for a small fuel cell, a GTL (gas to liquid) process for producing synthetic oil from natural gas, a GTL-FPSO process applicable to a marine environment, a petrochemical process, a fine chemical process, and an energy and environmental process.

A microchannel reactor is provided with micro-wide microchannels (reaction channels (110)) inside through which various fluids flow to promote reactions. These microchannels can be made by a LIGA method that combines precision machining, chemical etching, X-ray etching, plating, and casting on the surface of a metal sheet.

The above microchannel (reaction path (110)) should be narrow in width and deep in relation to its width, which is desirable in terms of catalytic reaction or heat exchange. In order to increase the capacity of a unit reactor, a plurality of microchannel plates having microchannels formed thereon may be stacked so that the fluid supplied to the reactor is distributed and flows through the microchannels of each plate constituting the reactor. In this case, it is common for each microchannel (reaction path (110)) to constitute an independent reaction space.

However, as described above, if the width of the microchannel (reaction path (110)) is reduced, there is a risk that the reaction path (110) may be blocked due to coking, in which carbon accumulates on the surface of the catalyst during the reaction, lowering the reactivity, and sintering, in which nanoparticles clump together. This may also lead to safety issues caused by increased reactor pressure.

To solve this problem, according to the present invention, at least one sub-movement path (120) is provided in the middle of the catalyst layer (100) to connect adjacent reaction paths (110). The sub-movement path (120) means an opening (hole) from which a portion of the catalyst layer (100) is removed.

The sub-channels (120) connect adjacent reaction channels (110) so that when a particular reaction channel (110) is blocked by coking and/or sintering, the reactants can flow to another adjacent reaction channel (110).

A plurality of sub-movement paths (120) may be provided, and in one embodiment, the number may be 2 or more and 10 or less. When the number of sub-movement paths (120) is less than 2, the effect of connecting the reaction path (110) by the sub-movement paths (120) may be minimal. Conversely, when more than 10 sub-movement paths (120) are provided, the gas flowing through the reaction path (110) does not flow in one direction but continues to fall into the sub-movement paths (120), which may reduce the flowability of the reactants. Accordingly, the reaction efficiency may be reduced. The number of sub-movement paths (120) may be designed in consideration of the size of the reactor, the amount of reactants, etc. When the number of sub-movement paths (120) is 2 or more and 10 or less, the flow rate of the reactants flowing through the reaction path (110) can be appropriately reduced, thereby increasing the Fischer-Tropsch reaction amount.

A sub-movement path (120) may be provided in the middle region of the reaction path (110). In this case, the middle region may mean an area excluding the inlet region and the outlet region of the reaction path (110). The sub-movement path (120) is a member provided to improve the flow of reactants when the reaction path (110) is blocked during a reaction. Since the Fischer-Tropsch reaction has not yet occurred significantly in the inlet region of the reaction path (110), there is little concern that the reaction path (110) will be blocked by the reaction. Therefore, if the sub-movement path (120) is provided in the inlet region of the reaction path (110), the bypass effect when the reaction path (110) is blocked is minimal, and rather, the sub-movement path (120) may spread the reactants like a diffuser, thereby hindering the reactants from flowing along one reaction path (110). In addition, even if the sub-movement path (120) is provided in the outlet area of the reaction path (110), the effect of diversion of the reactants when the reaction path (110) is blocked is minimal because it only affects the movement of the reaction products after the reaction is mostly completed.

When multiple sub-movement paths (120) are provided, the multiple sub-movement paths (120) may be provided spaced apart from each other. This is because when the sub-movement paths (120) are adjacent and clustered together, the amount of reactants falling into the sub-movement paths (120) rather than flowing along the reaction path (110) may be large, which may reduce the flowability of the reactants and the reaction efficiency.

The sub-channel (120) may have a width of 1 mm to 10 mm. By having a width in the above-described range, when used with a microchannel (reaction channel (110)) having a diameter of 1 mm to 100 mm, it is possible to provide a bypass when a blockage occurs in the reaction channel (110) without impeding the flow of reactants along the reaction channel (110).

Meanwhile, a catalyst layer inlet through which reactants are supplied may be provided on one side of the catalyst layer (100), and a catalyst layer outlet through which products are discharged may be provided on the other side. The catalyst layer inlet and the catalyst layer outlet may be provided at opposite positions with a region filled with catalyst therebetween. The catalyst layer (100) inlet and the catalyst layer (100) outlet may be provided at a sufficient distance apart from each other. Accordingly, all reactants may be converted into reaction products through an exothermic reaction, and the reaction products may be discharged.

Additionally, a refrigerant layer may be provided adjacent to the catalyst layer (100). A plurality of refrigerant layers may be provided, and in this case, the refrigerant layers may be provided facing each other with the catalyst layer (100) interposed therebetween. The refrigerant layer can remove heat generated in the Fischer-Tropsch reaction.

Meanwhile, additional safety panels may be provided on the outer surface of the reactor. The safety panels may be provided on both sides of the reactor. The safety panels may be provided to protect the refrigerant layer or catalyst layer (100) provided within the reactor from external impacts. The safety panels may be provided in various thicknesses, shapes, and materials as long as they can prevent external impacts.

The above describes a reactor according to one embodiment of the present invention. Below, the Fischer-Tropsch reaction efficiency of the reactors of the embodiment and comparative examples is compared to confirm the superior effectiveness of the reactor according to the present invention.

In the following examples and comparative examples, a microchannel reactor is disclosed in which eight catalyst layers are provided and reaction channels are provided between the catalyst layers and between the catalyst layers and the outer panel (a total of nine reaction channels). The macrochannel reactor of the comparative example does not provide sub-channels connecting adjacent reaction channels. The reactor of Example 1 is provided with two sub-channels each having a width of 30 mm for each catalyst layer. The reactor of Example 2 is provided with four sub-channels each having a width of 15 mm for each catalyst layer. The reactor of Example 3 is provided with six sub-channels each having a width of 10 mm for each catalyst layer.

The Fischer-Tropsch reaction was performed in the reactors of the examples and comparative examples, at which time the inlet temperature of the reactor was maintained at 233°C and the pressure inside the reactor was maintained at 22 bar. The reaction gas composed of a molar ratio of H ₂ 0.57, CO 0.28, CO ₂ 0.09, and Ar 0.06 was injected into the reactor at a rate of 5921.4 mL/g-cat/h (based on CO+H ₂ ) and the reaction was performed.

Figure 2a shows the results of analyzing the Fischer-Tropsch reaction efficiency at steady state without blockage in the reactors of the examples and comparative examples. Figure 2b shows the results of analyzing the flow velocity within the flow path at steady state without blockage in the reactors of the examples and comparative examples. Figure 2c shows the results of analyzing the temperature distribution within the flow path at steady state without blockage in the reactors of the examples and comparative examples.

Referring to Fig. 2a, when no channeling occurred in the reactor, the comparative example showed a CO conversion rate of 66.815%, Example 1 showed a CO conversion rate of 68.311%, Example 2 showed a CO conversion rate of 68.402%, and Example 3 showed a CO conversion rate of 68.907% according to the Fischer-Tropsch reaction. In the reactor according to the example, the reaction amount increased as the flow rate decreased in the section where the sub-movement path was provided, and accordingly, it was found that the CO conversion rate according to the Fischer-Tropsch reaction increased by about 2% compared to the comparative example.

Referring to Fig. 2b, it can be confirmed that the flow rate of the reactants is significantly reduced in the areas where sub-pathways are provided in Examples 1, 2, and 3. Therefore, it can be seen that by providing sub-pathways, the flow rate of the reactants can be appropriately reduced and the Fischer-Tropsch reaction amount can be increased. However, since the flow rate of the reactants is significantly reduced in the areas where sub-pathways are provided, it can also be seen that if there are too many sub-pathways, the movement speed of the reactants may be reduced, making it difficult to achieve a smooth reaction.

Referring to Fig. 2c, it can be confirmed that when there is no reaction path blockage, the temperature distribution according to the reaction is similar to that of the example and comparative example.

Next, we examined the movement of reactants and the reaction pattern when a blockage occurred in the reaction path.

Figure 3a shows the results of analyzing the Fischer-Tropsch reaction efficiency when blockage occurred in the reactors of the examples and comparative examples. Figure 3b shows the results of analyzing the flow velocity within the flow path when blockage occurred in the reactors of the examples and comparative examples. Figure 3c shows the results of analyzing the temperature distribution within the flow path when blockage occurred in the reactors of the examples and comparative examples.

In Figures 3a to 3c, the reaction efficiency, flow rate, and temperature behavior when channeling occurred in the fifth reaction path were analyzed.

Referring to Fig. 3a, when a blockage occurs in one reaction path, it can be confirmed that in the comparative example, the CO conversion rate was 62.806%, which was significantly reduced compared to when there was no blockage (66.815%) because the reaction did not proceed smoothly in the blocked path. In contrast, in the cases of Examples 1 to 3, the CO conversion rates were 67.825%, 68.236%, and 69.065%, respectively, which were similar to when there was no blockage. In particular, when comparing Examples 1 to 3, it can be confirmed that in Example 3, where the distance between sub-movement paths is relatively short, the effect of the blockage was reduced, and accordingly, the CO conversion rate increased.

Referring to Figures 3b and 3c, it can be confirmed that the reactants do not flow and the reaction does not occur in the area where the blockage occurs, and in the case where the distance between the sub-movement paths is short, as in Example 3, it can be confirmed that the size of the area where the blockage occurs is reduced.

Next, we examined the movement of reactants and the reaction patterns when occlusion occurred in multiple reaction channels.

Figure 4a shows the results of analyzing the Fischer-Tropsch reaction efficiency when multiple channels were blocked in the reactors of the examples and comparative examples. Figure 4b shows the results of analyzing the flow velocity within the channels when multiple channels were blocked in the reactors of the examples and comparative examples. Figure 4c shows the results of analyzing the temperature distribution within the channels when multiple channels were blocked in the reactors of the examples and comparative examples.

In Figures 4a to 4c, the reaction efficiency, flow rate, and temperature behavior when channeling occurred in the first and fifth reaction channels were analyzed.

Referring to Fig. 4a, when blockage occurred in two reaction channels, in the comparative example, two reaction channels did not participate in the reaction, and it can be confirmed that the CO conversion rate decreased significantly to 58.238%. However, in the case of Examples 1 to 3, the CO conversion rate was 66.829%, 67.692%, and 68.993%, respectively, confirming that it did not decrease significantly even when blockage occurred in two channels. In particular, in the case of Example 3, it can be confirmed that the distance between the sub-movement paths was relatively short, so the effect of blockage was reduced, and accordingly, the CO conversion rate increased.

Referring to Figures 4b and 4c, it can be confirmed that the reactants do not flow and the reaction does not occur in the area where the blockage occurs, and in the case where the distance between the sub-movement paths is short, as in Example 3, it can be confirmed that the size of the area where the blockage occurs is reduced.

Finally, we examined the movement of reactants and the reaction patterns when occlusions occurred randomly in multiple regions within the reaction channel.

Figure 5a shows the results of analyzing the Fischer-Tropsch reaction efficiency when multiple channels were blocked in the reactors of the examples and comparative examples. Figure 5b shows the results of analyzing the flow velocity within the channels when multiple channels were blocked in the reactor of the examples. Figure 5c shows the results of analyzing the temperature distribution within the channels when multiple channels were blocked in the reactor of the examples.

Comparing the comparative example with Example 3, it can be confirmed that in Example 3, the CO conversion rate is not significantly reduced because the reactants flow while avoiding the area where the blockage occurred. In particular, referring to the drawing, it can be confirmed that when the blockage area is located at the front of the reactor (close to the inlet), the Fischer-Tropsch reaction occurs as the reactants flow again behind the area where the blockage occurred.

In contrast, in the comparative example, it can be seen that no reaction occurs in the reaction path where blockage occurs, and thus the CO conversion rate is reduced to half.

From the above description, those skilled in the art will understand that the present application can be implemented in other specific forms without altering its technical concept or essential characteristics. In this regard, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of this application should be interpreted to include all changes or modifications derived from the meaning and scope of the following claims and their equivalents, rather than the detailed description above.

Claims (5)

(a) multiple catalyst layers promoting the Fischer-Tropsch reaction;
(b) a refrigerant layer provided adjacent to the catalyst layer;
(c) a plurality of reaction channels having a diameter of 1 mm to 10 mm extending in one direction defined by a plurality of catalyst layers;
(d) at least one sub-movement path is provided in the middle of the catalyst layer and includes two or more and ten or less sub-movement paths connecting the adjacent reaction paths,
A microchannel reactor in which the reactants of the Fischer-Tropsch reaction move through the reaction channel, and when a part of the reaction channel is blocked, the reactants move through the sub-channel to the adjacent reaction channel. delete delete delete delete