Multi-channel reactor with temperature control function and application thereof

Abstract

The present application relates to the technical field of catalytic reaction, and discloses a multi-channel reactor with temperature control function and application thereof.The multi-channel reactor comprises a temperature control zone and at least one reaction tube; the temperature control zone comprises a cold air channel, a wind baffle, a side wall, a fixed end and a moving end; a reaction bed heat exchange area is arranged in the reaction tube, and the reaction bed heat exchange area is arranged in a space formed by the side wall and the outer wall of the cold air channel; wherein, the air outlet of the cold air channel is located in a chamber formed by the side wall, the fixed end and the moving end, the wind baffle and the cold air channel are connected with the fixed end through an adjustable connecting piece, and the wind baffle is arranged on the upper end of the air outlet of the cold air channel, for changing the flow direction of cold air in the cold air channel, so that the cold air enters the space formed by the side wall and the outer wall of the cold air channel. The reactor of the present application can more effectively and accurately realize reaction heat removal, the amount of heat removal medium is small, and energy saving and consumption reduction can be realized.

Description

Technical Field

[0001] This invention relates to the field of catalytic reaction technology, specifically to a multi-channel reactor with temperature control function and its application. Background Technology

[0002] Ethylene is an important product of petrochemicals and organic chemicals, and its demand is increasing year by year with the development of the world economy. Currently, ethylene is mainly produced through petroleum cracking. However, with the depletion of petroleum energy resources, there is a need to find a method to replace petroleum cracking in ethylene production. Methane is a major component of natural gas, shale gas, coalbed methane, and methane hydrate (combustible ice), all of which are abundant in the Earth's reserves and are considered clean energy sources. Therefore, from a long-term perspective, methane-to-ethylene technology has a promising future.

[0003] However, the oxidative coupling of methane to ethylene is a strongly exothermic reaction. During the reaction, the heat of reaction needs to be removed in time to avoid local overheating in the multi-channel reactor, which would affect the performance of the catalyst and cause further exothermic reactions due to deep oxidation.

[0004] 4CH4+O2→2C2H6+2H2O(g)△H=-353.6kJ / mol

[0005] 2CH4+O2→C2H4+2H2O(g)△H=-281.67kJ / mol

[0006] 2CH4+3O2→2CO+4H2O(g)△H=-346.22kJ / mol

[0007] 1 / 2CH4+O2→1 / 2CO2+H2O(g)△H=-401.16kJ / mol

[0008] As can be seen from the above formulas, the process of methane oxidation into ethylene and ethane is exothermic. The excess heat generated by these reactions can promote the conversion of methane into carbon monoxide and carbon dioxide. The deep oxidation reaction further increases the exothermic heat of the reaction. Therefore, the instantaneous large amount of heat released by the reaction places higher demands on the heat removal capacity of the reactor.

[0009] While multichannel reactors are advantageous for increasing feed throughput, they also place higher demands on heat removal capabilities. Therefore, there is an urgent need to find a heat removal method suitable for multichannel reactors. Summary of the Invention

[0010] The purpose of this invention is to overcome the aforementioned technical problems in the prior art and to provide a multi-channel reactor with temperature control function and its application.

[0011] To achieve the above objectives, the first aspect of the present invention provides a multi-channel reactor with temperature control function, the multi-channel reactor including a temperature control zone and at least one reaction tube;

[0012] The temperature control zone includes a cold air channel, a wind baffle, a side wall, a fixed end, and a movable end;

[0013] The reaction tube is provided with a reaction bed heat exchange area, which is located in the space formed by the side wall and the outer wall of the cold air channel;

[0014] The air outlet of the cold air duct is located in the cavity formed by the side wall, the fixed end and the moving end. The wind baffle and the cold air duct are connected to the fixed end through an adjustable connector. The wind baffle is set at the upper end of the air outlet of the cold air duct to change the direction of the cold air flow in the cold air duct, so that the cold air enters the space formed by the side wall and the outer wall of the cold air duct.

[0015] The second aspect of the present invention provides a method for producing C2 hydrocarbons by oxidative coupling of methane, the method comprising, under the reaction conditions for producing C2 hydrocarbons by oxidative coupling of methane, introducing methane and oxygen into a multi-channel reactor as described in the first aspect to contact with a catalyst filled in a reaction tube, and during the contact process, introducing cold air into a cold air channel to reduce the hot spot temperature.

[0016] The multi-channel reactor with temperature control function of the present invention can achieve reaction heat removal more effectively and accurately, and the amount of heat removal medium used is small, which can achieve energy saving and consumption reduction.

[0017] The multi-channel reactor with temperature control function of the present invention has a wide range of applications. By adjusting the adjustable height segmented support, it can meet the length requirements of different reaction bed heat exchange zones.

[0018] The multi-channel reactor with temperature control function of the present invention is suitable for medium and high temperature reactions, especially for reactions with reaction temperatures of 500-1000℃.

[0019] Using the multi-channel reactor with temperature control function of the present invention for the oxidative coupling of methane to C2 hydrocarbons can significantly improve the selectivity of C2 hydrocarbons. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a specific embodiment of the multi-channel reactor of the present invention.

[0021] Explanation of reference numerals in the attached figures

[0022] 1 Temperature control zone 2 Cold air passage

[0023] 3 reaction tubes 4 wind deflectors

[0024] 5. Side wall 6. Fixed end

[0025] 7 Mobile devices 8 Connectors

[0026] 9 Adjustable height segmented support; 10 Semi-insulation layer

[0027] 11 Raw material imports 12 Raw material exports

[0028] 13 First thermal insulation layer 14 Second thermal insulation layer Detailed Implementation

[0029] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0030] In this invention, "alkane-oxygen ratio" refers to the molar ratio of alkane to oxygen.

[0031] In this invention, unless otherwise stated, "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0032] In this invention, "C2 hydrocarbons" include ethane and ethylene, but exclude acetylene.

[0033] In this invention, "C2+" includes hydrocarbons with two or more carbon atoms.

[0034] In this invention, "inner diameter" refers to "diameter".

[0035] The first aspect of the present invention provides a multi-channel reactor with temperature control function, the multi-channel reactor comprising a temperature control zone 1 and at least one reaction tube 3;

[0036] The temperature control zone 1 includes a cold air channel 2, a wind baffle 4, a side wall 5, a fixed end 6, and a movable end 7;

[0037] The reaction tube 3 is provided with a reaction bed heat exchange area, which is located in the space formed by the side wall 5 and the outer wall of the cold air channel 2;

[0038] The air outlet of the cold air channel 2 is located in the cavity formed by the side wall 5, the fixed end 6 and the moving end 7. The wind baffle 4 and the cold air channel 2 are connected to the fixed end 6 through an adjustable connector 8. The wind baffle 4 is located at the upper end of the air outlet of the cold air channel 2 to change the direction of the cold air flow in the cold air channel 2 so that the cold air enters the space formed by the side wall 5 and the outer wall of the cold air channel 2.

[0039] In this invention, the position of the moving end 7 is set according to the length of the heat exchange area of ​​the reaction bed before the reaction begins. That is, by adjusting the position of the moving end 7, the heat exchange area of ​​the reaction bed is located in the space formed by the side wall 5 and the outer wall of the cold air channel 2. In other words, the heat exchange area of ​​the reaction bed is located in the space formed by the fixed end 6 and the moving end 7.

[0040] According to the present invention, preferably, the heat exchange region of the reaction bed in the reaction tube 3 is filled with a catalyst. The type of catalyst is not particularly limited and can be any catalyst in the art that can be used for the oxidative coupling of methane to C2 hydrocarbons.

[0041] According to the present invention, preferably, the inner surface of the portion of the reaction tube 3 in contact with the catalyst has an inert metal coating; more preferably, the inert metal coating is a nickel metal coating; even more preferably, the thickness of the metal coating is 0.01-0.05 mm (e.g., 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm). This method can prevent the active metal in the reaction tube from affecting the performance of the catalyst.

[0042] According to the present invention, the material of the reaction tube 3 can be selected according to the substance introduced into the reaction tube and the chemical reaction that occurs. However, in order to better control the temperature inside the reaction tube, preferably, the material of the reaction tube 3 is a thermally conductive metal material. More preferably, the thermal conductivity of the thermally conductive metal material is greater than 10 W / (m·K), more preferably 12-100 W / (m·K), and even more preferably, the thermally conductive metal material is stainless steel (e.g., 310s stainless steel, 316L stainless steel) and / or Inconel 825.

[0043] In this invention, the 310s stainless steel comprises iron, chromium, nickel, and titanium.

[0044] In this invention, the 316L stainless steel comprises iron, chromium, nickel, and titanium.

[0045] In this invention, the composition of the Inconel 825 includes nickel, chromium, iron, copper, and titanium.

[0046] According to the present invention, preferably, the distance between the fixed end 6 and the moving end 7 is 0.01L-0.5L, wherein the length of the reaction tube 3 is represented by L.

[0047] According to the present invention, preferably, the distance between the wind deflector 4 and the air outlet of the cold air channel 2 is 1-15mm, more preferably 3-15mm.

[0048] According to the present invention, preferably, the cross-sectional area of ​​the cold air channel 2 is 16-100 times the cross-sectional area of ​​the reaction tube 3. The cross-sectional area of ​​the reaction tube 3 refers to the cross-sectional area of ​​a single reaction tube, excluding the wall thickness of the reaction tube.

[0049] In this invention, the cold air channel 2 can be cylindrical or rectangular.

[0050] According to the present invention, the type of connector is not particularly limited, as long as it enables the air baffle 4 and the air outlet of the cold air channel 2 to move along the raw material flow direction. Preferably, the connector 8 is a flange. The distance between the connector 8 and the air baffle 4 is adjustable. Typically, the position of the air outlet of the cold air channel 2 within the temperature control zone 1 is adjusted by adjusting the distance between the connector 8 and the air baffle 4. The distance between the air outlet of the cold air channel 2 and the air baffle 4 can be adjustable or non-adjustable. Typically, the distance between the air outlet of the cold air channel 2 and the air baffle 4 is set to a fixed value before the reactor starts operating, and this distance is not adjusted during the reaction operation.

[0051] According to the present invention, preferably, the wind deflector 4 includes a fixing frame and a wind deflector blade, wherein the fixing frame is arranged perpendicularly to the cold air channel 2. The wind deflector blade is fixed to the fixing frame with screws, and the shape of the wind deflector blade can be planar or curved, as long as it can change the flow direction of the cold air discharged from the air outlet of the cold air channel 2.

[0052] According to the present invention, preferably, such as Figure 1 As shown, the sidewall 5 includes a first sidewall connected to the fixed end 6 and a second sidewall connected to the movable end 7. The first sidewall is fixed to the fixed end 6, and the second sidewall can move downward with the movable end 7. There may be no gap between the first sidewall and the second sidewall, or there may be a gap. When there is a gap, the gap should be as small as possible.

[0053] According to the present invention, the multi-channel reactor can be adjusted and reassembled according to the length of the heat exchange zone of the reaction bed. Preferably, the multi-channel reactor further includes an adjustable height segmented support 9 disposed outside the moving end 7. The length of the adjustable height segmented support 9 is adjustable. After the catalyst is loaded, the moving end 7 can be moved parallel to the reaction tube 3 by adjusting the length of the adjustable height segmented support 9, so that the heat exchange zone of the reaction bed is located within the space formed by the fixed end 6 and the moving end 7. Then, the semi-insulating layer 10, the first thermal insulation layer 13, and the second thermal insulation layer 14 are assembled.

[0054] According to the present invention, preferably, the thickness of the adjustable height segmented support 9 is 0.3-0.5 cm. The adjustable height segmented support 9 is composed of multiple heat-insulating bricks stacked together, and the length of the heat-insulating bricks is 0.5-1 cm. The number of heat-insulating bricks can be changed according to actual needs, thereby adjusting the length of the adjustable height segmented support 9.

[0055] According to the present invention, the mobile terminal may also be provided with an exhaust vent to discharge the cold air after heat exchange with the reaction tube.

[0056] According to the present invention, preferably, the outer wall, wind baffle 4, side wall 5, fixed end 6 and moving end 7 of the cold air channel 2 are made of 310s stainless steel.

[0057] According to the present invention, preferably, the multi-channel reactor further includes a semi-insulating layer 10, which encloses the fixed end 6, the sidewall 5, and the adjustable height segmented support 9 internally. More preferably, the thickness of the semi-insulating layer 10 is 0.4-0.7 cm.

[0058] According to the present invention, preferably, the outer wall of the cold air duct 2 is provided with a heat insulation layer. The heat insulation layer on the outer wall of the cold air duct 2 is used to prevent the hot air in the temperature control zone 1 from heating the cold air in the cold air duct 2. This method can reduce the amount of cold air used. More preferably, the thickness of the heat insulation layer on the outer wall of the cold air duct 2 is 0.3-0.5 cm.

[0059] According to the present invention, preferably, the heat insulation layers of the adjustable height segmented support 9, the semi-insulation layer 10, and the outer wall of the cold air channel 2 are each independently made of ceramic heat insulation material. More preferably, the ceramic heat insulation material is corundum.

[0060] According to the present invention, such as Figure 1 As shown, preferably, the reaction tube 3 is provided with a raw material inlet 11 and a raw material outlet 12, the raw material inlet 11 being close to the fixed end 6 and the raw material outlet 12 being close to the moving end 7.

[0061] According to the present invention, preferably, the multi-channel reactor further includes a first thermal insulation layer 13 disposed upstream of the reaction tube. More preferably, the first thermal insulation layer 13 is disposed at the upper end of the semi-insulation layer 10 outside the fixed end 6. A heating device is provided inside the first thermal insulation layer 13 for heating the raw materials entering the reaction tube 3.

[0062] According to the present invention, preferably, one end of the adjustable height segmented support 9 is connected to the movable end 7, and the other end is connected to the second thermal insulation layer 14.

[0063] According to the present invention, preferably, the number of reaction tubes 3 is 6-18 (for example, it can be 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18).

[0064] According to the present invention, preferably, the interval between two adjacent reaction tubes 2 is equal or unequal, but preferably equal.

[0065] According to the present invention, the reaction tubes can be evenly distributed around the cold air channel.

[0066] According to the present invention, preferably, the inner diameter of the reaction tube 3 is 3-10 mm (for example, it can be 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, or 10 mm).

[0067] According to the present invention, preferably, the wall thickness of the reaction tube 3 is 1-2 mm (for example, it can be 1 mm, 1.5 mm, or 2 mm).

[0068] According to the present invention, preferably, a temperature sensing element is provided inside the reaction tube 3. More preferably, the temperature sensing element is a thermocouple. The temperature sensing element is used to detect the temperature at various points inside the reaction tube 3. When the temperature at a certain point in the heat exchange area of ​​the reaction bed is detected to be higher than the set temperature of the heating device in the first thermal insulation layer 13, the position of the air outlet of the cold air channel 2 can be adjusted to be parallel to that point, so that the cold air discharged from the outlet directly contacts the reaction tube at that point, achieving precise temperature control. The adjustment of the position of the air outlet of the cold air channel 2 based on the temperature of the thermocouple inside the reaction tube can be achieved manually or through a control system.

[0069] The second aspect of the present invention provides a method for producing C2 hydrocarbons by oxidative coupling of methane, the method comprising, under the reaction conditions for producing C2 hydrocarbons by oxidative coupling of methane, introducing methane and oxygen into a multi-channel reactor as described in the first aspect to contact with a catalyst filled in a reaction tube, and during the contact process, introducing cold air into a cold air channel to reduce the hot spot temperature.

[0070] According to the present invention, preferably, the feed temperature of methane and oxygen is 400-900°C, more preferably 450-830°C.

[0071] According to the present invention, preferably, the molar ratio of methane to oxygen is 2-10:1 (for example, it can be 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1), and more preferably 3-8:1.

[0072] According to the present invention, preferably, the volume hourly space velocity (VHSV) of the methane is 10,000-150,000 mL / (g·h), for example, it can be 10,000 mL / (g·h), 20,000 mL / (g·h), 30,000 mL / (g·h), 40,000 mL / (g·h), 50,000 mL / (g·h), 60,000 mL / (g·h), 70,000 mL / (g·h), 80,000 mL / (g·h), 90,000 mL / (g·h), 100,000 mL / (g·h), 110,000 mL / (g·h), 120,000 mL / (g·h), 130,000 mL / (g·h), 140,000 mL / (g·h), or 150,000 mL / (g·h).

[0073] According to the present invention, preferably, the cold air is air. More preferably, the temperature of the air is 15-40°C.

[0074] According to the present invention, preferably, the flow rate of the cold air is not specifically limited, but is adjusted according to the highest temperature of the heat exchange zone of the reaction bed. When the temperature at a certain point in the heat exchange zone of the reaction bed is higher than the set temperature of the heating device in the first insulation layer, cold air is introduced into the cold air channel, and the outlet of the cold air channel is set at the point with the highest temperature in the heat exchange zone of the reaction bed. The flow rate of the cold air is adjusted according to the temperature difference; the larger the temperature difference, the greater the flow rate of the cold air, and the smaller the temperature difference, the smaller the flow rate of the cold air. When the temperature at various points in the heat exchange zone of the reaction bed is approximately equal to the set temperature of the heating device in the first insulation layer (i.e., the temperature difference is within 1-2℃), the flow rate of the cold air is set to zero. Using the above method, not only can the temperature of the heat exchange zone of the reaction bed be precisely controlled, but the amount of cold air used can also be reduced.

[0075] According to the present invention, the catalyst can be any catalyst in the art that can be used for the oxidative coupling of methane to C2 hydrocarbons. Preferably, the catalyst comprises a support and an active component supported on the support, wherein the support is at least one selected from silica, alumina, calcium oxide, lanthanum oxide, and barium titanate, and the active component is at least one selected from sodium tungstate, manganese oxide, lithium oxide, and cerium oxide. Preferably, the content of the active component, calculated as a metal element, is 0.1-15% by weight based on the total weight of the catalyst. For example, the catalyst in CN103657640B can be used.

[0076] The following is in conjunction with the appendix Figure 1The workflow of the multi-channel reactor with temperature control function of the present invention is described as follows: First, the catalyst is loaded. The top of the heat exchange area of ​​the reaction bed is located below the fixed end 6. After the catalyst is loaded, the position of the moving end 7 is adjusted by adjusting the length of the adjustable height segment support 9 so that the moving end 7 is located below the bottom of the heat exchange area of ​​the reaction bed. Then, the raw material enters the reaction tube 3 from the raw material inlet 11. After being heated by the heating device in the first heat insulation layer 13, it continues to flow downward and contact the catalyst in the reaction tube 3, and then is discharged from the raw material outlet 12. At the same time, the position of the air outlet of the cold air channel 2 is adjusted according to the temperature detected at various points in the reaction tube 3 by the thermocouple. The position of the air outlet of the cold air channel 2 can be adjusted by adjusting the distance between the connector 8 and the baffle 4. When the cold air introduced into the cold air channel 2 enters the temperature control zone 1, it first collides with the baffle 4 and changes its flow direction, so that the cold air flows in the space surrounded by the baffle 4, the side wall 5 and the moving end 7 and exchanges heat with the reaction tube 3, thereby achieving precise control of the temperature in the reaction tube 3.

[0077] The following specific embodiments further illustrate the structural features and performance of the multi-channel reactor with temperature control function described in this invention.

[0078] Gas chromatography was used to analyze and detect the components of the product.

[0079]

[0080]

[0081]

[0082] The catalyst used in Examples 1, 2, and Comparative Example 1 was Na-W-Mn / BaTiO3, prepared by the method in Example 1 of patent CN103657640B.

[0083] Examples 3 and 4 use the lanthanum oxycarbonate catalyst prepared by the method in Example 1 of CN113797949A (application number 202010549901.1).

[0084] In the following examples, "cold air" refers to air at approximately 25°C.

[0085] In the following examples, the reaction tube is made of 310s stainless steel, which has a thermal conductivity of 12 W / (m·K).

[0086] In the following embodiments, the materials of the heat insulation layer on the outer wall of the adjustable height segmented support 9, the semi-insulation layer 10, and the cold air channel 2 are all corundum.

[0087] Example 1

[0088] like Figure 1As shown, the cylindrical multi-channel reactor includes a temperature control zone 1 and six reaction tubes 3. The temperature control zone 1 includes a cold air channel 2, a baffle plate 4, a side wall 5, a fixed end 6, and a moving end 7. The reaction tubes 3 are provided with a reaction bed heat exchange area, which is located in the space formed by the side wall 5 and the outer wall of the cold air channel 2. The baffle plate 4 and the cold air channel 2 are connected to the fixed end 6 through an adjustable connector 8 (flange), and the baffle plate 4 is located at the upper end of the air outlet of the cold air channel 2 to change the flow direction of the cold air in the cold air channel 2 so that the cold air enters the space formed by the side wall 5 and the outer wall of the cold air channel 2.

[0089] The movable end 7 is provided with an adjustable-height segmented support 9 of adjustable length below it, for moving the movable end 7 in a direction parallel to the reaction tube 3. The fixed end 6, the side wall 5, and the outer wall of the adjustable-height segmented support 9 are provided with a semi-insulating layer 10. The outer wall of the cold air channel 2 is provided with an insulation layer to prevent the hot air in the temperature control zone 1 from heating the cold air in the cold air channel 2. The thicknesses of the insulation layers of the adjustable-height segmented support 9, the semi-insulating layer 10, and the outer wall of the cold air channel 2 are 0.6 cm, 0.4 cm, and 0.3 cm, respectively.

[0090] The reaction tube 3 has a raw material inlet 11 and a raw material outlet 12. The raw material inlet 11 is located near the fixed end 6, and the raw material outlet 12 is located near the moving end 7. A first thermal insulation layer 13 is provided at the raw material inlet 11, and a heating device is installed inside the first thermal insulation layer 13 to heat the raw material entering the reaction tube 3 to a specified temperature. The thickness of the nickel metal plating inside the reaction tube 3 is 0.02 mm. A thermocouple is installed inside the reaction tube 3, and the spacing between adjacent reaction tubes is equal.

[0091] The wind deflector 4 includes a mounting frame and a wind deflector blade. The wind deflector blade is fixed on the mounting frame, which is perpendicular to the cold air duct 2. The wind deflector blade is made of 310s stainless steel and has a flat shape.

[0092] The reaction tube 3 has a length L = 500 mm, a radius R = 5 mm, and a wall thickness of 1 mm. 0.1 g of catalyst is loaded into each reaction tube, meaning the length of the heat exchange zone in the reaction bed is 5 mm. After catalyst loading, the moving end 7 is adjusted to be below the bottom of the heat exchange zone in the reaction bed, meaning the distance between the fixed end 6 and the moving end 7 is 6 mm. Simultaneously, the distance between the baffle plate 4 and the outlet of the cold air channel 2 is set to 2 mm. The cold air channel 2 is cylindrical, with an inner diameter of 40 mm, meaning its cross-sectional area is 16 times the cross-sectional area of ​​the reaction tube 3.

[0093] The above-mentioned multi-channel reactor is used to carry out the oxidative coupling reaction of methane to produce C2 hydrocarbons. This method for the oxidative coupling of methane to produce C2 hydrocarbons includes:

[0094] Methane and oxygen are introduced into the raw material inlet 11, and then heated to 800°C by a heating device located within the first thermal insulation layer 13. The methane space velocity introduced into each reaction tube is 10000 mL / (g·h), and the alkane-to-oxygen ratio is 4:1. When a thermocouple in reaction tube 3 detects that the temperature at a certain point in the heat exchange area of ​​the reaction bed is higher than the set temperature of the heating device in the first thermal insulation layer 13, and the temperature difference between that point and the set temperature is the largest, the position of the air outlet of the cold air channel 2 is adjusted to that point to achieve precise temperature control. Simultaneously, the cold air flow rate in the cold air channel 2 is adjusted according to the magnitude of the temperature difference between that point and the set temperature of the heating device, ensuring that the temperature difference between all points in the heat exchange area of ​​the reaction bed and the set temperature of the heating device is within 10°C.

[0095] After 100 hours of reaction, the methane conversion rate was 36%, the C2 hydrocarbon selectivity was 67%, the C2 hydrocarbon yield was 24.1%, the C2+ selectivity was 71%, and the C2+ yield was 25.5%. During the reaction, no localized temperature runaway occurred in any part of the reaction tube, effectively controlling the temperature rise in the heat exchange zone of the reaction bed during the exothermic reaction of methane oxidative coupling.

[0096] Compared to the case where the outer wall of the cold air duct 2 has no heat insulation layer and the position of the air outlet of the cold air duct 2 is not adjustable, this embodiment saves 20-25% of the amount of cold air entering the cold air duct 2 and reduces energy consumption by about 15%.

[0097] Example 2

[0098] The difference between the multi-channel reactor in this embodiment and that in Embodiment 1 is:

[0099] There are six reaction tubes 3, each with a length L = 500 mm, radius R = 5 mm, and wall thickness 1 mm. 0.2 g of catalyst is loaded into each reaction tube, resulting in a 10 mm long heat exchange zone in the reaction bed. After loading, the moving end 7 is adjusted to be below the bottom of the heat exchange zone, meaning the distance between the fixed end 6 and the moving end 7 is 12 mm. Simultaneously, the distance between the baffle 4 and the outlet of the cold air channel 2 is set to 5 mm. The cold air channel 2 is cylindrical, with an inner diameter of 50 mm, meaning its cross-sectional area is 25 times the cross-sectional area of ​​the reaction tubes 3.

[0100] In this embodiment, the oxidative coupling of methane to C2 hydrocarbons is carried out in a multi-channel reactor. The method for oxidative coupling of methane to C2 hydrocarbons includes:

[0101] Methane and oxygen are introduced into the raw material inlet 11, and then heated to 750°C by a heating device located within the first thermal insulation layer 13. The methane space velocity introduced into each reaction tube is 40,000 mL / (g·h), and the alkane-to-oxygen ratio is 3:1. When a thermocouple in reaction tube 3 detects that the temperature at a certain point in the heat exchange area of ​​the reaction bed is higher than the set temperature of the heating device in the first thermal insulation layer 13, and the temperature difference between that point and the set temperature is the largest, the position of the outlet of the cold air channel 2 is adjusted to that point to achieve precise temperature control. Simultaneously, the cold air flow rate in the cold air channel 2 is adjusted according to the magnitude of the temperature difference between that point and the set temperature of the heating device, ensuring that the temperature difference between all points in the heat exchange area of ​​the reaction bed and the set temperature of the heating device is within 10°C.

[0102] After 100 hours of reaction, the methane conversion rate was 37.8%, the C2 hydrocarbon selectivity was 67.5%, the C2 hydrocarbon yield was 25.5%, the C2+ selectivity was 72%, and the C2+ yield was 27.2%. During the reaction, no localized temperature runaway occurred in any part of the reaction tube, effectively controlling the temperature rise in the heat exchange zone of the reaction bed during the exothermic reaction of methane oxidative coupling.

[0103] Compared to the case where the outer wall of the cold air duct 2 has no heat insulation layer and the position of the air outlet of the cold air duct 2 is not adjustable, this embodiment saves 30-35% of the amount of cold air entering the cold air duct 2 and reduces energy consumption by about 20%.

[0104] Example 3

[0105] The difference between the multi-channel reactor in this embodiment and that in Embodiment 1 is:

[0106] There are six reaction tubes 3, each with a length L = 500 mm, radius R = 5 mm, and wall thickness of 1 mm. 0.3 g of catalyst is loaded into each reaction tube, resulting in a 15 mm long heat exchange zone in the reaction bed. After loading, the moving end 7 is adjusted to be below the bottom of the heat exchange zone, meaning the distance between the fixed end 6 and the moving end 7 is 18 mm. Simultaneously, the distance between the baffle plate 4 and the outlet of the cold air channel 2 is set to 5 mm. The cold air channel 2 is cylindrical, with an inner diameter of 54.8 mm, meaning its cross-sectional area is 30 times the cross-sectional area of ​​the reaction tube 3.

[0107] In this embodiment, the oxidative coupling of methane to C2 hydrocarbons is carried out in a multi-channel reactor. The method for oxidative coupling of methane to C2 hydrocarbons includes:

[0108] Methane and oxygen are introduced into the raw material inlet 11, and then heated to 550°C by a heating device located within the first thermal insulation layer 13. The methane space velocity introduced into each reaction tube is 100,000 mL / (g·h), and the alkane-to-oxygen ratio is 8:1. When a thermocouple in reaction tube 3 detects that the temperature at a certain point in the heat exchange area of ​​the reaction bed is higher than the set temperature of the heating device in the first thermal insulation layer 13, and the temperature difference between that point and the set temperature is the largest, the position of the air outlet of the cold air channel 2 is adjusted to that point to achieve precise temperature control. Simultaneously, the cold air flow rate in the cold air channel 2 is adjusted according to the magnitude of the temperature difference between that point and the set temperature of the heating device, ensuring that the temperature difference between all points in the heat exchange area of ​​the reaction bed and the set temperature of the heating device is within 10°C.

[0109] After 100 hours of reaction, the methane conversion rate was 20.1%, the C2 hydrocarbon selectivity was 62.1%, the C2 hydrocarbon yield was 12.5%, the C2+ selectivity was 63.2%, and the C2+ yield was 12.7%. During the reaction, no localized temperature runaway occurred in any part of the reaction tube, effectively controlling the temperature rise in the heat exchange zone of the reaction bed during the exothermic reaction of methane oxidative coupling.

[0110] Compared to the case where the outer wall of the cold air duct 2 has no heat insulation layer and the position of the air outlet of the cold air duct 2 is not adjustable, this embodiment saves 40-45% of the amount of cold air entering the cold air duct 2 and reduces energy consumption by about 25%.

[0111] Example 4

[0112] The multi-channel reactor in this embodiment is the same as that in Embodiment 1.

[0113] In this embodiment, the oxidative coupling of methane to C2 hydrocarbons is carried out in a multi-channel reactor. The method for oxidative coupling of methane to C2 hydrocarbons includes:

[0114] Methane and oxygen are introduced into the raw material inlet 11, and then heated to 500°C by a heating device located within the first thermal insulation layer 13. The methane space velocity introduced into each reaction tube is 100,000 mL / (g·h), and the alkane-to-oxygen ratio is 7:1. When a thermocouple in reaction tube 3 detects that the temperature at a certain point in the heat exchange area of ​​the reaction bed is higher than the set temperature of the heating device in the first thermal insulation layer 13, and the temperature difference between that point and the set temperature is the largest, the position of the outlet of the cold air channel 2 is adjusted to that point to achieve precise temperature control. Simultaneously, the cold air flow rate in the cold air channel 2 is adjusted according to the magnitude of the temperature difference between that point and the set temperature of the heating device, ensuring that the temperature difference between all points in the heat exchange area of ​​the reaction bed and the set temperature of the heating device is within 10°C.

[0115] After 100 hours of reaction, the methane conversion rate was 21.3%, the C2 hydrocarbon selectivity was 61.2%, the C2 hydrocarbon yield was 13%, the C2+ selectivity was 64.7%, and the C2+ yield was 13.8%. During the reaction, no localized temperature runaway occurred in any part of the reaction tube, effectively controlling the temperature rise in the heat exchange zone of the reaction bed during the exothermic reaction of methane oxidative coupling.

[0116] Compared to the case where the outer wall of the cold air duct 2 has no heat insulation layer and the position of the air outlet of the cold air duct 2 is not adjustable, this embodiment saves 15-20% of the amount of cold air entering the cold air duct 2 and reduces energy consumption by about 13%.

[0117] Comparative Example 1

[0118] The multi-channel reactor used in this comparative example is a commercially available, standard multi-channel reactor with six reaction tubes. Reaction tube 3 has a length L = 500 mm, a radius R = 5 mm, and a wall thickness of 1 mm. No heat exchange components are installed inside the multi-channel reactor; that is, there is no cooling air to cool the reaction tubes. 0.2 g of catalyst is loaded into each reaction tube, resulting in a reaction bed region length of 10 mm.

[0119] In this comparative example, the oxidative coupling of methane to C2 hydrocarbons was carried out in a multi-channel reactor. This method for oxidative coupling of methane to C2 hydrocarbons includes:

[0120] Methane and oxygen were introduced into the inlet of the reaction tube, and then heated to 750°C. The methane space velocity in each reaction tube was 40,000 mL / (g·h), and the alkane-to-oxygen ratio was 3:1.

[0121] After 3 hours of reaction, the temperature inside the reaction tube was detected to exceed 880°C, and the reaction was stopped.

[0122] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A multi-channel reactor with temperature control function, characterized in that, The multichannel reactor includes a temperature control zone (1) and at least one reaction tube (3); The temperature control zone (1) includes a cold air channel (2), a wind deflector (4), a side wall (5), a fixed end (6), and a movable end (7). The reaction tube (3) is provided with a reaction bed heat exchange area, which is located in the space formed by the side wall (5) and the outer wall of the cold air channel (2); The air outlet of the cold air channel (2) is located in the cavity formed by the side wall (5), the fixed end (6) and the moving end (7). The wind baffle (4) and the cold air channel (2) are connected to the fixed end (6) through an adjustable connector (8). The wind baffle (4) is set at the upper end of the air outlet of the cold air channel (2) to change the direction of the cold air flow in the cold air channel (2) so that the cold air enters the space formed by the side wall (5) and the outer wall of the cold air channel (2). The distance between the fixed end (6) and the moving end (7) is 0.01L-0.5L; wherein the length of the reaction tube (3) is represented by L; The multi-channel reactor also includes an adjustable height segmented support (9) disposed on the outside of the movable end (7); The outer wall of the cold air duct (2) is provided with a heat insulation layer.

2. The multi-channel reactor according to claim 1, wherein, The multichannel reactor also includes a semi-insulating layer (10) that encloses the fixed end (6), sidewall (5) and adjustable height segmented support (9) inside.

3. The multi-channel reactor according to claim 1, wherein, The reaction tube (3) is provided with a raw material inlet (11) and a raw material outlet (12). The raw material inlet (11) is close to the fixed end (6), and the raw material outlet (12) is close to the moving end (7).

4. The multi-channel reactor according to claim 2, wherein, The multi-channel reactor also includes a first thermal insulation layer (13) disposed upstream of the reaction tube, and a heating device is provided inside the first thermal insulation layer (13).

5. The multi-channel reactor according to claim 1, wherein, The number of reaction tubes (3) is 6-18; And / or, the inner diameter of the reaction tube (3) is 3-10 mm; And / or, the reaction tube (3) is provided with a temperature measuring element.

6. A method for the oxidative coupling of methane to produce C2 hydrocarbons, characterized in that, The method includes, under the conditions of methane oxidative coupling to produce C2 hydrocarbons, introducing methane and oxygen into a multi-channel reactor as described in any one of claims 1-5 to contact the catalyst packed inside the reaction tube, and during the contact process, introducing cold air into the cold air channel to reduce the hot spot temperature.

7. The method according to claim 6, wherein, The feed temperature for methane and oxygen is 400-900℃; And / or, the molar ratio of methane to oxygen is 2-10:1; And / or, the space velocity of the methane is 10,000-150,000 mL / (g·h). And / or, the cold air is air.

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