Reactor for catalytic processing of hydrocarbon-containing raw materials

Abstract

The solution relates to gas chemistry, more specifically to technologies for the catalytic processing of hydrocarbon-containing feedstock and the production of synthesis gas. The reactor comprises a body 1, the upper portion of which contains a burner 5 and an inlet 6 for feeding a feedstock mixture. A target product outlet 7 is provided at the base 2, and a layer of inert material 9, a layer of catalytic material 10, and a protective layer 11 are arranged in sequence. A multi-zone temperature sensor 12 is installed at the base 2, implemented in the form of a vertical protective tube, in which lower and upper temperature sensors are installed for measuring the temperature in the catalyst layer at different heights. The lower temperature sensor is installed at a height of 20% to 30% of the catalyst layer thickness, and the upper sensor is installed at a height of 40% to 60% of the catalyst layer thickness. The technical result consists of a simplified design.

Description

[0001] Field of technology to which the utility model belongs

[0002] The utility model relates to the field of gas chemistry, more specifically to technologies for the catalytic processing of hydrocarbon-containing raw materials, the production of synthesis gas, in particular, to autothermal reforming reactors.

[0003] Technology Level

[0004] A prior art discloses a method and reactor for the catalytic processing of hydrocarbon-containing feedstock. The reactor comprises a housing with a burner and an inlet for feeding a feedstock mixture at the top, a bed of catalytic material at the base, and an outlet for the target product. Multi-zone temperature sensors are installed in the reactor walls to measure the temperature in the catalyst bed (patent document US 2023016861, published January 19, 2033). A disadvantage of this known solution is the horizontal arrangement of the multi-zone sensors, which interferes with catalyst loading into the reactor and creates uneven filling. Excessive sensors take up space within the reactor, reducing its useful volume and decreasing productivity.

[0005] The essence of the utility model

[0006] This utility model solves the problem of simplifying the reactor design and increasing its efficiency.

[0007] The achieved technical result consists in reducing the loss of useful volume of the reactor, increasing the uniformity of filling the reactor with catalyst due to the vertical arrangement of temperature sensors.

[0008] The specified technical result is achieved in that the reactor for catalytic processing of hydrocarbon-containing raw materials contains a housing, in the upper part of which a burner and an inlet for feeding a raw material mixture are installed, and in the base there is an outlet for the target product and a layer of inert material, a layer of catalytic material and a protective layer are sequentially located, in the base there is a multi-zone temperature sensor, made in the form of a vertical protective tube, in which temperature sensors are installed for measuring the temperature in the catalyst layer at different heights.

[0009] Lower and upper sensors can be installed inside the vertical protective tube, wherein the said lower temperature sensor is installed at a height of 20% to 30% of the thickness of the catalyst layer, and the upper sensor is installed at a height of 40% to 60% of the thickness of the catalyst layer.

[0010] A distinctive feature of the proposed solution is the vertical placement of a multi-zone sensor inside the catalyst layer and temperature measurement at only two points at different heights.

[0011] List of drawing figures

[0012] Fig. 1 shows a sectional view of the reactor.

[0013] Fig. 2 shows a cross-section of a multi-zone temperature sensor.

[0014] In FIG. 3 shows the burner.

[0015] Fig. 4 shows the inner and outer nozzles of the burner.

[0016] Fig. 5 shows a top view of the protective layer.

[0017] Fig. 6 shows a tile of the peripheral part of the protective layer.

[0018] Fig. 7 shows the tile of the central part of the protective layer.

[0019] Fig. 8 shows a section of the supporting vault.

[0020] Fig. 9 shows the structure of the supporting arch block.

[0021] Implementation of a utility model

[0022] The autothermal reforming (ATR) reactor and process are designed to convert hydrocarbon feedstock into syngas, a mixture of hydrogen (H2), carbon monoxide (CO), and carbon dioxide (CO) in varying proportions. A key feature of the ATR technology is the implementation of two thermodynamically opposed processes within a single reactor: exothermic non-catalytic partial oxidation and endothermic catalytic steam reforming. The thermal energy required for the endothermic reactions is generated directly within the reactor due to exothermic reactions, eliminating the need for external heat input, unlike tubular reforming furnaces.

[0023] The ATR reactor comprises a vertical cylindrical body 1, including a base 2, a combustion chamber 3 and an upper part 4.

[0024] The upper part 4 of the reactor body 1 contains an oxygen burner 5 and an inlet 6 for feeding the feedstock. The base 2 contains an outlet 7 for the target product.

[0025] Burner 5 provides:

[0026] - intensive and uniform mixing of hydrocarbon feedstock, steam and oxidizer flows;

[0027] - formation of a stable torch with controlled geometry to protect the reactor walls and catalyst from overheating;

[0028] - high flow rate into the combustion chamber.

[0029] The upper part 4 of the body with the burner 5 installed in it is also designed for feeding reagents (raw materials and oxidizer) through separate channels.

[0030] Combustion chamber 3 of body 1 is located directly below the upper part 4 and homogeneous reactions of partial oxidation and steam reforming take place in it.

[0031] At the base 2 of the reactor 1, a support vault 8 is installed, on top of which an inert layer 9, a catalyst layer 10 and a protective layer 11 are placed. The catalyst layer 10 (catalytic zone) is a region with a fixed catalyst bed located below the combustion zone in which steam reforming reactions occur.

[0032] Support dome 8 ensures uniform distribution of the target product gas flow and can be designed as a truncated pyramid with evenly spaced gas flow channels in the side walls. Support dome 8 can be constructed from blocks of inert, heat-resistant material with a high alumina or corundum content.

[0033] Combustion chamber 3 is separated from catalyst layer 10 by a protective layer 11 of inert heat-resistant material, which may consist, for example, of a solid and perforated heat-resistant tile with a special laying pattern or a layer of aluminum oxide balls.

[0034] The protective layer 11, made, for example, in the form of balls of material with a high content of aluminum oxide or corundum, serves as a barrier and protects the catalyst from direct exposure to flame, and also prevents the catalyst from moving under the influence of gas flows in the chamber.

[0035] The inner surface of reactor vessel 1 is equipped with a protective lining made of refractory brick or concrete with a high alumina content. The lining can be multilayered, consisting of materials with different thermal conductivities, to protect the steel vessel from high temperatures, minimize heat loss, and create the required temperature profile inside the reactor.

[0036] The efficiency of hydrocarbon processing in a catalytic process is determined by the optimal operating temperature of the catalyst. Overheating the catalyst leads to degradation of its properties and deterioration of processing quality, since the upper layers of the catalyst, located closer to the combustion chamber, are at the highest risk of overheating. Therefore, real-time monitoring of the catalyst's temperature allows for early detection of when the permissible temperature is exceeded and the implementation of process measures to reduce the temperature in the combustion chamber, for example, by reducing the oxidizer supply to the combustion zone.

[0037] Currently, there are tools for modeling the temperature regime in the catalyst bed and the ability to calculate the thermal field and temperature value at any point in the catalyst bed based on temperature measurements at several points.

[0038] At least one multi-zone temperature sensor 12 is vertically installed in the base 2 of the housing 1, configured to simultaneously measure the temperature at several points at different heights inside the catalyst bed 10. To improve the quality of monitoring the state of the catalyst, two or more sensors 12 can be installed in the reactor. It is advisable to ensure their uniform distribution in the catalyst bed relative to the axis of symmetry of the reactor.

[0039] It is advisable to use a two-zone temperature sensor 12, which can be made in the form of thermocouples 13, 14 installed inside a protective tube 15, as shown in Fig. 2.

[0040] The lower sensor 14 is preferably installed within the catalyst bed 10 at a height A, which is between 20% and 30% of the catalyst bed thickness. The upper sensor 15 is preferably installed within the catalyst bed 10 at a height B, which is between 40% and 60% of the catalyst bed thickness. Measuring the temperature at at least two points along the height of the catalyst bed 10 allows for highly accurate determination of the temperature regime of the catalyst particles throughout the bed 10 and, thereby, the onset of catalyst overheating in the upper portions of the bed 10. This, in turn, allows for control of the operating mode of the burner 5 to reduce the combustion temperature.

[0041] To improve the accuracy of measuring the temperature state of the catalyst, it is advisable to install several sensors 12 with several meters along the height of the catalyst layer 10. In large reactors, three- and four-zone sensors 12 can be used to improve the accuracy of determining the temperature in the catalyst layer.

[0042] The reactor body 1 can be equipped with sensors for measuring the temperature and pressure in the combustion zone, the temperature of the walls of the body 1 at the base and the combustion chamber.

[0043] Torch 5 contains devices for uniform mixing of gas flows, cooling and protective channels to prevent overheating of the metal.

[0044] Burner 5 includes a channel 16 for supplying oxidizer, a branch pipe 17 for supplying water vapor into channels 18 located parallel to channel 16. Inside channel 16 for supplying oxidizer, a fairing 19 is located, equipped with a temperature sensor 20, and a protective tube 40 for connection with the temperature sensor 20. Fairing 19 is a bluff body for imparting developed turbulence to the gas flow.

[0045] The burner 5 includes an inner nozzle 21 having an edge 26 and a shell 25 for creating an annular channel 27 for supplying water vapor around the inner nozzle 21. The channel 27 communicates with the channels 18 for supplying water vapor.

[0046] Burner 5 is equipped with an outer nozzle 23, which communicates with an annular feed channel 28 for the raw material. The outer nozzle 23 may be equipped with a perforated baffle 22 to equalize the flow of raw materials.

[0047] A fairing 24 is installed outside the outer nozzle 23, creating an annular bypass around the edges of the outer nozzle.

[0048] The structural elements of burner 5 are made of special heat-resistant and corrosion-resistant steels.

[0049] The oxidizer is fed into the internal cavity of the burner into the combustion zone through the internal nozzle 21 with the fairing 19. The raw material is fed through the inlet 6 into the annular channel 28, preferably through the perforated partition 22 and the external nozzle 23. The presence of the perforated partition 22 increases the uniformity of the feed gas mixture supply to the external nozzle and further into the combustion zone.

[0050] A small portion of the raw gas mixture can pass through the fairing 24 and the annular bypass, providing cooling of the outer surface of the outer nozzle 23 and protecting it from hot flows in the combustion chamber 3. The bypassed raw gas, mixing with the hot gas from the outer nozzle 23, is additionally converted under the influence of high temperatures.

[0051] The protective steam is supplied through the channels 18 into the space of the shell 25, forming an annular flow for cooling the edge 26 of the inner nozzle 21 and moving the ignition zone away from the edge 26 of the inner nozzle.

[0052] Separation of the supply channels for the oxidizer, raw mixture and water vapor allows controlling the operating mode of the burner 5 and controlling the temperature in the combustion chamber 3 based on information from sensors 12.

[0053] The protective layer 11 is made of tiles made of a material with a high content of alumina or zirconium dioxide and having the shape of a straight regular hexagonal prism with a height of 150 mm to 250 mm. The protective layer 11 has a gas-impermeable central portion 29 and a peripheral portion 30 made of tiles with openings. The central portion 29 prevents direct communication between the catalyst layer and the high-temperature gas flow from the burner 5 and prevents the high-temperature gas flow from entering the catalyst layer 10, ensuring internal recirculation of the high-temperature gas for the most complete completion of the partial oxidation and reforming reactions in the combustion chamber. The catalyst layer 10 communicates with the combustion chamber 3 through the openings 31 of the tiles 32 of the peripheral part 30, which ensures the equalization of the temperature regime in the catalyst layer 10. The tiles 33 of the central part 29 are made solid.

[0054] It is advisable to make the openings 31 in the tiles 32 of the peripheral part of the protective layer 11 along the sides of the hexagons equidistant from the outer sides of the tile 32, as shown in Fig. 6. It has been experimentally established that the optimal total area of ​​the openings 31 should be from 0.2 to 0.3 of the area of ​​the tile 32.

[0055] The supporting arch 8 is made of blocks 34 made of a material with a high content of alumina or zirconium dioxide. The blocks 34 are laid in the shape of a pyramid and form an internal space 39, which communicates with the external space through a channel 38 in the blocks 34. The block 34 has a base 35 in the form of an annular segment with side walls 36 and an end wall 37, in which a recess is made forming a channel 38. The blocks 34 are laid in rows, wherein the walls 36 and 37 of the blocks of the upper row are installed on the bases 35 of the blocks of the lower row to form a hollow pyramid in the shape of a right circular cone. The channels 28 ensure the alignment of the gas flow of the target product before it enters the outlet 7 of the body 1.

[0056] The reforming process in the ATR reactor includes the following steps.

[0057] Stage 1: Partial oxidation in combustion chamber 3.

[0058] The raw steam-gas mixture and oxidizer are fed through separate channels into the combustion chamber via burner device 5. Combustion of some hydrocarbons occurs, characterized by high temperatures in the combustion chamber (1100-1500°C) and occurs without a catalyst.

[0059] СН4+ 1 / 2O2→ CO + 2H2(ΔH = -36 kJ / mol)

[0060] СН4+ 1 1 / 2O2→ CO + 2H2O (ΔH ≈ -520 kJ / mol)

[0061] 2H2+ O2 → 2H2O (ΔH = -242 kJ / mol)

[0062] The released heat heats the flow to a temperature sufficient to initiate endothermic reactions in the homogeneous phase of the combustion zone and steam reforming in the catalyst bed (catalytic zone) 10.

[0063] Stage 2: Homogeneous reactions of steam reforming and conversion in the combustion zone.

[0064] Below the direct flame oxidation zone, in combustion chamber 3, where the temperature remains high (1100-1400°C), homogeneous (non-catalytic) steam methane reforming reactions begin. These reactions are endothermic and are initiated by the heat released during the partial oxidation stage.

[0065] Steam reforming of methane occurs according to the scheme

[0066]

[0067] At this stage, there is a significant increase in the volume of synthesis gas due to the formation of hydrogen and a decrease in the flow temperature to a level optimal for the subsequent catalytic stage (about 1100-1350°C at the entrance to catalytic zone 10).

[0068] Stage 3: Catalytic steam reforming.

[0069] A hot syngas stream containing unreacted methane, water vapor, CO, CO2, and H2 enters the catalytic zone into a fixed bed 10 of high-temperature nickel-based catalyst (Ni / Al2O3, Ni / MgAl2O4) or, for special applications, noble metals. Catalysts of various types and sizes are loaded in layers to ensure conversion, reduce temperature, and prevent carbon formation.

[0070] In the catalytic layer 10, the following chemical reactions occur at high speed on the catalyst surface:

[0071] - catalytic steam methane reforming:

[0072] - catalytic conversion of carbon monoxide:

[0073] Catalyst layer (catalytic zone) 10 provides:

[0074] 1) achieving (approaching the optimal value) thermodynamic equilibrium of reforming reactions, ensuring almost complete conversion of methane (residual CH4 content is usually 0.5-3% of dry gas).

[0075] 2) establishing the required H2 / CO ratio in the final synthesis gas by regulating the degree of CO conversion.

[0076] The endothermic nature of the primary reforming reaction leads to a further decrease in the gas flow temperature along the catalytic bed. The outlet temperature of the target product (syngas) is typically 950-1100°C.

[0077] To ensure safe and efficient operation of the ATR reactor, the following key parameters are monitored:

[0078] - O2 / C and H2O / C ratios.

[0079] - optimal values ​​of temperature and pressure.

[0080] The O2 / C ratio determines the heat balance, the H2 / CO ratio in the target product, and the process temperature. The H2O / C ratio determines the composition of the target product (syngas) and prevents soot formation.

[0081] In most cases, the optimal process operating pressure is 15-50 bar.

[0082] Example of implementation of the utility model.

[0083] The raw material mixture used is a steam-gas mixture consisting of methane (CH4), water vapor (H2O), hydrogen (H2), carbon monoxide (CO) and carbon dioxide (CO2) in the following volumetric proportions:

[0084] СН4- 0.58;

[0085] H2O - 0.33;

[0086] H2- 0.05;

[0087] CO - 0.01;

[0088] CO2- 0.03.

[0089] The feedstock mixture is fed to inlet 6 of reactor vessel 1 at a temperature of 600 to 750°C. Oxidizer (oxygen) is fed into channel 16 at a temperature of 150-300°C. After passing through fairing 18, the oxidizer flow becomes turbulent and exits from inner nozzle 21 into the combustion chamber.

[0090] Water vapor is supplied through pipe 17 to channels 18 at a temperature of 350-450°C and a pressure 2-8 Bar higher than the pressure of the supplied raw mixture.

[0091] At the outlet of the inner nozzle 21, the oxidizer mixes with the feed gas mixture inside the outer nozzle 23, forming a gas flame in which the chemical reactions described above occur. The gas mixture then penetrates the peripheral section 30 of the insulating layer 11 into the catalyst layer 10, where the feed gas is converted into the target product.

[0092] Streams of water vapor and raw gas mixture create a curtain around the edges of the inner nozzle 21 and outer nozzle 23, ensuring their cooling and increasing the homogeneity of the combustible mixture.

[0093] For the catalyst type used (nickel), a thermal field model (temperature distribution) is constructed within the catalyst bed. By measuring the temperature with dual-zone sensors 12, the temperature regime of the upper portion of the catalyst bed 10 is determined using the calculated thermal field model. If the optimum temperature is exceeded, the temperature in combustion chamber 3 is controlled by regulating the oxidizer flow through channel 16.

[0094] The gas flow passing through the catalyst layer 10 passes the inert layer 9 and through the channels 38 and uniformly enters the inner part 39 of the support arch 8 and then to the outlet 7 of the housing 1.

[0095] This solution provides the following benefits.

[0096] There is no need for external heat supply through the reactor vessel walls, simplifying the design. The ATR reactor offers high flexibility in terms of feedstock and target product. The proposed ATR reactor can process a wide range of feedstocks, from natural gas to heavy hydrocarbons, including with carbon dioxide recycle. By adjusting the O2 / C and H2O / C ratios, syngas can be produced with a wide range of H2 / CO ratios, from 1.5 for Fischer-Tropsch synthesis to values ​​above 3.0 for hydrogen and ammonia production.

[0097] The proposed solution provides high productivity per unit volume of equipment in a compact design of the ATR reactor and burner relative to a traditional tubular furnace with faster start-up and load change compared to tubular reforming.

[0098] The carbon dioxide capture rate reaches 99%, minimizing atmospheric emissions. A single unit can produce large volumes of syngas for various process lines and products.

Claims

1. A reactor for the catalytic processing of hydrocarbon-containing raw materials, comprising a housing, in the upper part of which a burner and an inlet for feeding a raw material mixture are installed, and in the base of which an outlet for the target product is provided and a layer of inert material, a layer of catalytic material and a protective layer are arranged in sequence, a multi-zone temperature sensor is installed in the base, made in the form of a vertical protective tube, in which temperature sensors are installed for measuring the temperature in the catalyst layer at different heights.

2. The reactor according to paragraph 1, characterized in that lower and upper sensors are installed inside the vertical protective tube, wherein said lower temperature sensor is installed at a height of 20% to 30% of the thickness of the catalyst layer, and the upper sensor is installed at a height of 40% to 60% of the thickness of the catalyst layer.

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