A reactor for water-gas shift reaction and its application

Abstract

This invention discloses a reactor for water-gas shift reaction and its application. The reactor is suitable for water-gas shift reaction processes containing gaseous and liquid reactants. A reaction chamber is set inside a hollow, sealed cylinder formed by the reactor walls. The reaction chamber is a hollow, sealed chamber surrounded by porous material as its wall surface. A gaseous reactant inlet pipe penetrates the reactor wall and extends into the upper part of the reaction chamber, a liquid reactant inlet pipe penetrates the reactor wall and extends into the cylinder, and a reaction product outlet pipe penetrates the reactor wall and extends into the lower part of the reaction chamber. The catalyst for the water-gas shift reaction is packed in the reaction chamber. The water-gas shift reaction can be carried out under near-isothermal conditions. Water in the liquid reactant does not need to be pre-vaporized and is directly fed into the reactor in liquid form, saving the energy consumption required to transport the corresponding amount of water vapor. Simultaneously, a high molar ratio of water to carbon monoxide is maintained within the reactor, promoting complete conversion of carbon monoxide.

Description

Technical Field

[0001] This invention relates to a reactor and its application for water-gas shift reaction, belonging to the field of carbon monoxide conversion and hydrogen production technology. Background Technology

[0002] Water-gas shift refers to the reaction in which carbon monoxide and water vapor are converted into hydrogen and carbon dioxide under the action of a catalyst. The reaction equation is: CO + H₂O → H₂ + CO₂. This reaction is used in industrial production for hydrogen production and to adjust the ratio of hydrogen to carbon monoxide in syngas. Existing industrial plants all use adiabatic reactors to carry out gas-solid two-phase reactions at 200-500℃. The gas phase consists of reactants containing carbon monoxide and water vapor, while the solid phase is the catalyst. Water-gas shift is a strongly exothermic reaction with a heat of reaction of approximately 40 kJ / mol. The heat of reaction accumulates in the adiabatic reactor, causing a significant increase in temperature. Excessive temperature is detrimental to plant control and can lead to catalyst deactivation. Therefore, industrial production typically employs a staged, multi-stage shift process; before proceeding to the next stage of the shift reaction, the temperature of the reactants is pre-cooled through heat exchange. Patent documents CN1280180C, CN102001623B, CN102971252B, CN103508416B, CN102992264B, CN103449365B, CN104340958B, CN104098069B, CN105084313B, etc. provide specific examples of the above process.

[0003] Compared to the adiabatic hot water gas shift reaction process, using an isothermal reactor for water-gas shift simplifies the reaction process. Patent document CN1204038C discloses an isothermal sulfur-resistant carbon monoxide shift reaction process. This process uses a tubular or internally heat-exchange coil reactor, removing the heat of reaction from the catalyst bed through a heat transfer medium, thus ensuring the bed temperature is close to isothermal. Patent document CN104085855B discloses an external reverse humidification isothermal carbon monoxide shift reaction process using a dry gas detoxifier. This process incorporates heat exchange bent tubes within the reactor. Patent document CN110550602A discloses a high-concentration, controllable semi-isothermal carbon monoxide shift reaction process for carbonyl synthesis. This process uses a reactor divided into an isothermal reaction zone and an adiabatic reaction zone; the isothermal reaction zone is equipped with heat exchange tubes connected from bottom to top.

[0004] If hydrogen can be removed via a membrane separator during the water-gas shift reaction, not only can the carbon monoxide conversion rate be improved, but high-purity hydrogen can also be obtained directly. Patent document CN102482079B discloses a method for preparing a diluted hydrogen gas mixture. This method uses a membrane reactor for the water-gas shift reaction; the membrane used is a hydrogen-permeable membrane with a hydrogen permeability selectivity relative to carbon dioxide of at least 30. Patent document CN103359688B discloses a method for producing hydrogen of different purity grades using semi-coke oven gas. This method uses a membrane reactor to simultaneously carry out the water-gas shift reaction and separate hydrogen-containing products. Summary of the Invention

[0005] This invention aims to provide a reactor that overcomes the shortcomings of existing technologies and enables efficient and controllable water-gas conversion. To achieve this objective, the invention adopts the following technical solution:

[0006] A reaction chamber (2) is set inside a hollow, sealed cylinder formed by reactor walls (1). The reaction chamber (2) is a hollow, sealed chamber surrounded by porous material as its wall surface. A gaseous reaction feedstock inlet pipe (3) penetrates the reactor wall (1) and extends into the upper part of the reaction chamber (2). A liquid-phase reaction feedstock inlet pipe (4) penetrates the reactor wall (1) and extends into the cylinder. A reaction product outlet pipe (5) penetrates the reactor wall (1) and extends into the lower part of the reaction chamber (2). A catalyst (6) for the water-gas shift reaction is packed in the reaction chamber (2). This type of reactor is suitable for water-gas shift reaction processes containing both gaseous and liquid-phase reaction feedstocks.

[0007] In the reactor described in this invention, the number of reaction chambers arranged inside the cylinder is 1-100.

[0008] In the reactor of the present invention, the porous material constituting the wall of the reaction chamber is at least one of porous sintered metal, porous ceramic, and metal mesh, or is made of two or more of these composite materials.

[0009] In the reactor described in this invention, the number of liquid phase reaction raw material input pipes is 1-10.

[0010] In the reactor described in this invention, the gas-phase reaction feedstock contains carbon monoxide, and the liquid-phase reaction feedstock contains water.

[0011] As needed, the technical solution provided by the present invention can be further optimized. Specifically, a gap can be left between the inner wall surface of the reactor wall and the outer wall surface of the reaction chamber.

[0012] As needed, the technical solution provided by the present invention can be further optimized. Specifically, a catalyst with a particle size of 1-200 mm can be selected and filled into the reaction chamber of the present invention to carry out the water-gas shift reaction.

[0013] As needed, the technical solution provided by the present invention can be further optimized. Specifically, a heat insulation layer can be provided on the outer wall surface of the reactor wall described in the present invention.

[0014] The water-gas shift reaction must be carried out under specific temperature and pressure conditions. The mechanical design of the reactor described in this invention must meet these conditions. The requirements and methods for reactor temperature and pressure design are well known to those skilled in the art.

[0015] The reactor for water-gas shift reaction provided by this invention is completely different from the design of existing water-gas shift reactors. This invention has the following beneficial effects:

[0016] First, using the reactor described in this invention, a water-gas shift reaction process comprising gaseous and liquid reactants can be realized. During this process, the liquid water, as a reactant, absorbs the heat released by the water-gas shift reaction and vaporizes, thereby maintaining a stable reaction temperature. This overcomes the problem of drastic temperature rise in gas-solid two-phase water-gas shift reactions using adiabatic reactors. The liquid water enters the reaction chamber through the sidewalls made of porous material, thus contacting the catalyst. This contact method ensures high heat transfer efficiency while avoiding large fluctuations in catalyst bed temperature due to rapid cooling. Under suitable liquid water input conditions, the water-gas shift reaction can proceed under near-isothermal conditions.

[0017] Secondly, the water in the liquid-phase reaction feedstock does not need to be pre-vaporized and is directly fed into the reactor in liquid form, thus eliminating the energy consumption required to transport the corresponding amount of water vapor. Simultaneously, it ensures that the molar ratio of water to carbon monoxide within the reactor remains at a high level, thereby promoting the reaction and ensuring complete carbon monoxide conversion simply by increasing the water flow rate without increasing energy consumption. Compared to methods using membrane reactors to improve carbon monoxide conversion, the method provided by this invention does not require additional membrane modules, and does not create difficulties in the manufacture, operation, or maintenance of the reaction apparatus. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the reactor described in Example 1;

[0019] Figure 2 This is a top view of the reactor described in Example 2. Detailed Implementation

[0020] The following embodiments will further illustrate the present invention. However, the present invention is not limited to the following embodiments.

[0021] Example 1

[0022] The reaction chamber 2 is constructed using nickel foam welding. The reaction chamber 2 is placed within the cylindrical body formed by the reactor wall 1, and is tightly fitted to the reactor wall 1. A gaseous reactant input pipe 3 and a reaction product output pipe 5, extending into the reaction chamber 2, are respectively installed at the upper and lower ends of the chamber. Both pipes penetrate the reactor wall 1 and connect to an external material system. A liquid-phase reactant input pipe 4, penetrating the reactor wall 1, is installed on the upper and middle parts of the same side of the reactor wall 1, and both pipes connect to an external material system. A cross-sectional view of the reactor is shown in the attached instruction manual. Figure 1 As shown.

[0023] Example 2

[0024] The number and position of the liquid-phase reaction feedstock inlet pipes 4 in the reactor described in Example 1 were adjusted. Three liquid-phase reaction feedstock inlet pipes 4, equidistant from each other, were installed on the upper part of the reactor wall 1. A top view of the resulting reactor is shown in the appendix to the instruction manual. Figure 2 As shown.

[0025] Example 3

[0026] The platinum-based water-gas shift catalyst was sieved, and 5-10 mesh (2-4 mm) particles were loaded into reaction chamber 2 of the reactor described in Example 1. The reactor was sealed, the air inside was replaced with nitrogen, and leaks were tested. Then, gaseous and liquid phase reactants were introduced. The gaseous reactant was an equimolar mixture of carbon monoxide and water vapor, preheated to 300°C before being fed into the reactor. The liquid phase reactant was water at 20°C. The molar ratio of the gaseous to liquid phase reactants was 4. The flow rates of water in the two liquid phase reactant input pipes 4 were equal. The reaction pressure was 4 MPa. After the reaction stabilized, the product exiting the reactor was at 362°C, and the carbon monoxide conversion rate was 86%.

[0027] Example 4

[0028] The reaction was carried out using the reactor described in Example 2. The catalyst dosage and reaction conditions were the same as in Example 3, and the water flow rates in the three liquid-phase reaction feedstock inlet pipes 4 were equal. After the reaction stabilized, the temperature of the product flowing out of the reactor was 368°C, and the carbon monoxide conversion rate was 89%.

Claims

1. A reactor for water-gas shift reaction, characterized in that, A reaction chamber (2) is provided inside a hollow, sealed cylinder formed by the reactor wall (1). The reaction chamber (2) is a hollow, sealed chamber surrounded by porous material as the wall surface. The gas phase reaction raw material input pipe (3) penetrates the reactor wall (1) and extends into the upper part of the reaction chamber (2). The liquid phase reaction raw material input pipe (4) penetrates the reactor wall (1) and extends into the cylinder. The reaction product output pipe (5) penetrates the reactor wall (1) and extends into the lower part of the reaction chamber (2). The catalyst (6) used for the water-gas shift reaction is filled in the reaction chamber (2). A gap is left between the inner wall surface of the reactor wall (1) and the outer wall surface of the reaction chamber (2). The number of liquid phase reaction raw material input pipes (4) is 3-10. The porous material constituting the wall of the reaction chamber (2) is at least one of porous sintered metal, porous ceramic, and metal mesh, or is made of two or more of these composite materials. The gas phase reaction feedstock is an equimolar mixture of carbon monoxide and water vapor, which is preheated to 300°C and then fed into the reactor. The liquid phase reaction feedstock is water.

2. The reactor for water-gas shift reaction according to claim 1, characterized in that, The number of reaction chambers (2) set inside the cylinder is 1-100.

3. The reactor for water-gas shift reaction according to claim 1, characterized in that, The catalyst (6) used for water-gas shift reaction is filled in the reaction chamber (2) with a particle size of 1-200 mm.

4. The reactor for water-gas shift reaction according to claim 1, characterized in that, A heat insulation layer is provided on the upper side of the outer wall surface of the reactor wall (1).

5. The application of the reactor for water-gas shift reaction as described in any one of claims 1-4, characterized in that, The reactor is used for water-gas shift reaction processes that include gaseous and liquid reactants.

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