Hydrogen-consuming self-heating propane dehydrogenation double-membrane reactor

Abstract

The invention provides a hydrogen-consuming self-heating propane dehydrogenation double-membrane reactor, and belongs to the field of petrochemical industry. The oxygen permeation membrane and the hydrogen permeation membrane are integrated into the propane dehydrogenation reactor, the oxygen permeation membrane separates oxygen from air to the reaction area to burn hydrogen for heat supply, the hydrogen permeation membrane removes redundant hydrogen after combustion from the reaction area, the propane conversion rate is remarkably increased, and the propane circulation amount and separation energy consumption of the propane dehydrogenation device are reduced. According to the hydrogen-consuming self-heating double-membrane reactor, the temperature and hydrogen partial pressure of the reaction zone are adjusted, the reaction temperature is controlled within the high temperature range of 600-650 DEG C, the propane partial pressure is increased, the one-way conversion rate of propane reaches 44% or above and is increased by 9-10% compared with a traditional process, the propane circulation amount is reduced by 29-34%, the combined action of high propylene selectivity and C3 recovery rate improvement is maintained, and the production cost is reduced. The consumption of the propane raw material is reduced by 0.5-3.0%, the treatment capacity of each operation unit is remarkably reduced, the public engineering cost is reduced by about 25%, and the cost advantage is remarkable.

Description

Technical Field

[0001] The invention belongs to the field of petrochemical industry, and in particular relates to a propane dehydrogenation double-membrane reactor which consumes hydrogen and supplies heat by itself. Background Art

[0002] Propylene is an important basic chemical raw material, with an annual global output of more than 100 million tons, which is used to produce derivatives such as polypropylene, acrylonitrile, isopropanol, and propylene oxide. With the rapid growth of demand for downstream products, the demand for propylene is increasing year by year. Propane dehydrogenation is the most efficient propylene production process. Compared with traditional processes such as steam cracking and catalytic cracking, it has the advantages of short process flow, small footprint, low equipment investment, and high yield. It has become an important way to solve the tight supply and demand relationship of propylene.

[0003] The main reactions in the propane dehydrogenation reactor include propane dehydrogenation, propane cracking, ethylene hydrogenation and coking reaction. The process is characterized by reversibility, strong endothermicity, selectivity and temperature sensitivity. Limited by the reaction equilibrium, the single-pass propane conversion rate is not high, and commercial devices can only reach about 40%. The low conversion rate leads to a large amount of propane circulation, and the energy consumption of the reaction raw material preheating and product compression liquefaction process is high. Therefore, the operating cost of the reaction-separation process of the traditional propane dehydrogenation process is relatively high.

[0004] Removing products from the reaction system is an important means to improve the conversion rate of reversible reactions. The hydrogen permeable membrane reactor removes hydrogen from the propane dehydrogenation reaction system, causing the propane dehydrogenation reaction to move in the direction of generating products, thereby improving the propane conversion rate. Propane dehydrogenation is a strongly endothermic reaction. The significant decrease in reaction temperature leads to limited improvement in propane conversion rate under adiabatic conditions in the hydrogen permeable membrane reactor, and efficient heat supply is required to achieve effective improvement. The oxygen permeable membrane reactor efficiently supplies heat by separating oxygen for combustion, but the heat of hydrogen combustion is close to twice the heat absorbed by propane dehydrogenation. As the reaction proceeds, heat gradually accumulates, and the excessively high reaction temperature leads to reduced selectivity, limiting further improvement in conversion rate.

[0005] The present invention provides a hydrogen-consuming self-heating propane dehydrogenation double-membrane reactor, wherein the double membrane comprises an oxygen-permeable membrane and a hydrogen-permeable membrane, wherein the oxygen-permeable membrane separates oxygen from the air to a reaction zone to burn hydrogen for heat supply, and the hydrogen-permeable membrane removes excess hydrogen after combustion from the reaction zone, and the two act synergistically to achieve matching of heat supply, hydrogen removal and dehydrogenation reaction, thereby significantly improving the single-pass conversion rate of the propane dehydrogenation process, reducing the amount of catalyst used and separation energy consumption, and significantly reducing the operating cost of the reaction-separation process. Summary of the invention

[0006] The present invention provides a propane dehydrogenation double-membrane reactor that consumes hydrogen and provides self-heating. The reactor separates oxygen through an oxygen permeable membrane to burn hydrogen to supply heat, and removes hydrogen through hydrogen combustion and hydrogen permeable membrane separation to improve the single-pass propane conversion rate.

[0007] The technical solution of the present invention is:

[0008] A propane dehydrogenation double membrane reactor consuming hydrogen and providing self-heating, comprising:

[0009] The reactor shell 14 has a reaction raw material inlet 6 at the top and a reaction product outlet 7 at the bottom;

[0010] Reaction zone 5, located inside reactor shell 14, for carrying out propane dehydrogenation reaction;

[0011] The oxygen permeable membrane 3 is installed in the reactor shell 14 and is used to push the oxygen in the air into the reaction zone 5 by using the oxygen partial pressure difference;

[0012] The hydrogen permeable membrane 4 is installed in the reactor shell 14 and is used to push the hydrogen in the reaction zone 5 into the purge gas by utilizing the hydrogen partial pressure difference;

[0013] The oxygen permeable membrane sealing head 12 is connected to the oxygen permeable membrane 3, and an air inlet 8 and an oxygen-depleted air outlet 9 are arranged on the outer side thereof;

[0014] A hydrogen permeable membrane head 13 is connected to the hydrogen permeable membrane 4, and a purge gas inlet 10 and a hydrogen-containing gas outlet 11 are arranged on the outer side thereof;

[0015] The oxygen permeable membrane 3 and the hydrogen permeable membrane 4 are assembled by tubular membranes, arranged perpendicularly to each other in the horizontal direction, and distributed in a uniform staggered manner in the height direction, that is, each layer of oxygen permeable membrane is staggered a certain distance from the adjacent hydrogen permeable membrane in the vertical direction to form a regular stacking structure, so that the oxygen permeable membrane and the hydrogen permeable membrane are uniformly distributed in the reaction zone.

[0016] Furthermore, the tubular membranes of the oxygen permeable membrane 3 and the hydrogen permeable membrane 4 are evenly distributed in the reaction zone 5 to ensure the transmission efficiency of oxygen and hydrogen in the reaction zone.

[0017] Furthermore, the reactor shell 14 and the oxygen permeable membrane head 12 and the hydrogen permeable membrane head 13 divide the interior of the reactor into five areas, the middle area being the reaction area 5, in which the hydrogen permeable membranes 3 and oxygen permeable membranes 4 are evenly distributed.

[0018] Furthermore, two areas outside the oxygen permeable membrane head 12 are provided with an air inlet 8 on one side and an oxygen-depleted air outlet 9 on the opposite side; two areas outside the hydrogen permeable membrane head 13 are provided with a purge gas inlet 10 on one side and a hydrogen-containing gas outlet 11 on the opposite side.

[0019] Furthermore, the oxygen permeable membrane is an oxygen permeable membrane that conducts both electrons and oxygen ions, and is used to transfer oxygen to the reaction zone to burn and supply heat;

[0020] The hydrogen permeable membrane is a silicon dioxide membrane, a carbon membrane or a palladium membrane, and is used to remove hydrogen in the reaction zone.

[0021] Furthermore, the permeation side of the hydrogen permeable membrane is compatible with both purge operation and vacuum operation, the purge gas is selected from one or a mixture of more than one of the following: water vapor, nitrogen, carbon dioxide, and the vacuum operation pressure range is 10 to 50 kPa;

[0022] The heater heats the membrane reactor feed to 400-800° C.;

[0023] The reaction pressure of the membrane reactor is 10-800 kPa.

[0024] Furthermore, a method for using a hydrogen-consuming self-heating propane dehydrogenation double membrane reactor comprises the following steps:

[0025] Air S-1, reaction raw material S-2 and purge gas S-3 are introduced into heater 1 and heated to reaction operating temperature;

[0026] The high temperature reaction raw material S-5 is introduced into the reaction zone 5 of the double membrane reactor 2, and a propane dehydrogenation reaction occurs to obtain a reaction product S-8;

[0027] High-temperature air S-4 is introduced into the oxygen-permeable membrane side of the double-membrane reactor 2, and oxygen in the air is pushed into the reaction zone 5 through the oxygen-permeable membrane 3 by using the oxygen partial pressure difference, thereby burning hydrogen and providing heat required for propane dehydrogenation, and the remaining oxygen-depleted air S-7 is discharged;

[0028] The high-temperature purge gas S-6 is introduced into the hydrogen permeable membrane side of the double membrane reactor 2, and the hydrogen in the reaction zone 5 is pushed into the purge gas through the hydrogen permeable membrane 4 by utilizing the hydrogen partial pressure difference to obtain a hydrogen-containing gas S-9.

[0029] The beneficial effect of the present invention is that through the coupling integration of oxygen permeable membrane and hydrogen permeable membrane, the precise supply of heat required for propane dehydrogenation reaction and the efficient removal of hydrogen are achieved. This innovative technology greatly increases the single-pass propane conversion rate to more than 44%, while significantly reducing the propane circulation volume by 29-34%, the compression energy consumption by 33-34%, the raw material heating load by 15-16%, and the cryogenic load by 21-24%. In summary, the hydrogen-consuming self-heating double-membrane reactor for propane dehydrogenation proposed in the present invention not only significantly improves the single-pass propane conversion rate compared to the traditional propane dehydrogenation process, but also achieves a significant reduction in separation energy consumption, providing a new technical path for the efficient and energy-saving development of the propane dehydrogenation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is the principle flow chart of a hydrogen-consuming self-heating double membrane reactor for propane dehydrogenation;

[0031] Explanation of symbols and numbers in the figure: 1, heater; 2, double membrane reactor; 3, oxygen permeable membrane; 4, hydrogen permeable membrane; 5, reaction zone; S-1, air; S-2, reaction raw material; S-3, purge gas; S-4, high temperature air; S-5, high temperature reaction raw material; S-6, high temperature purge gas; S-7, oxygen-depleted air; S-8, reaction product; S-9, hydrogen-containing gas.

[0032] Figure 2 It is a schematic diagram of the structure of a hydrogen-consuming self-heating double membrane reactor for propane dehydrogenation;

[0033] Explanation of symbols and numbers in the figure: 3, oxygen permeable membrane; 4, hydrogen permeable membrane; 5, reaction zone; 6, reaction raw material inlet; 7, reaction product outlet; 8, air inlet; 9, oxygen-depleted air outlet; 10, purge gas inlet; 11, hydrogen-containing gas outlet; 12, oxygen permeable membrane head; 13, hydrogen permeable membrane head; 14, reactor shell;

[0034] Figure 3 This is a comparison chart of the enhancement effect of oxygen-hydrogen permeable dual membrane synergistic coupling on propane conversion rate;

[0035] Figure 4 This is a comparison chart of the enhancement effect of oxygen-hydrogen permeable double membrane synergistic coupling on reaction temperature. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limitations on the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The embodiments of the present invention are described in detail below in conjunction with the drawings.

[0037] The principle process of the hydrogen-consuming self-heating double membrane reactor for propane dehydrogenation is as follows Figure 1As shown, air S-1, reaction raw material S-2, and purge gas S-3 enter heater 1, and are heated to the reaction operating temperature. High-temperature reaction raw material S-5 enters reaction zone 5 in double membrane reactor 2, and propane dehydrogenation reaction occurs to obtain reaction product S-8; high-temperature air S-4 enters the oxygen permeable membrane side of double membrane reactor 2, and oxygen permeable membrane 3 uses the oxygen partial pressure difference to push oxygen in the air into reaction zone 5, burns hydrogen and provides heat required for propane dehydrogenation, and the remaining oxygen-depleted air S-7 is discharged; high-temperature purge gas S-6 enters the hydrogen permeable membrane side of double membrane reactor 2, and hydrogen permeable membrane 4 uses the hydrogen partial pressure difference to push hydrogen in reaction zone 5 into the purge gas, and hydrogen-containing gas S-9 is obtained. The core unit of this reactor is a double membrane reactor equipped with both oxygen permeable membrane and hydrogen permeable membrane. The structure is shown in the figure below. Figure 2 As shown. In this double membrane reactor, the oxygen permeable membrane 3 and the hydrogen permeable membrane 4 are assembled with tubular membranes, arranged vertically to each other in the horizontal direction, and distributed in a uniform staggered manner in the height direction, that is, each layer of oxygen permeable membrane is staggered a certain distance from the adjacent hydrogen permeable membrane in the vertical direction to form a regular stacking structure, so that the oxygen permeable membrane and the hydrogen permeable membrane are evenly distributed in the reaction zone. A reaction raw material inlet 6 is arranged at the top of the reactor shell 14, and a reaction product outlet 7 is arranged at the bottom. The reactor shell 14 and the oxygen permeable membrane head 12 and the hydrogen permeable membrane head 13 divide the interior of the reactor into five areas. The middle area is the reaction zone 5, in which the hydrogen permeable membrane 3 and the oxygen permeable membrane 4 are evenly distributed; the two areas outside the oxygen permeable membrane head 12 are provided with an air inlet 8 on one side and an oxygen-depleted air outlet 9 on the opposite side; the two areas outside the hydrogen permeable membrane head 13 are provided with a purge gas inlet 10 on one side and a hydrogen-containing gas outlet 11 on the opposite side.

[0038] Embodiment 1:

[0039] For the 500,000 ton per year propylene plant, a hydrogen-consuming self-heating double membrane reactor for propane dehydrogenation was established. Figure 1 The process is shown. The feed rate of air S-1 is 4450 kmol / h, and the reaction raw material S-2 includes 2615 kmol / h propane and 1835 kmol / h diluted hydrogen. The temperature is raised to 650°C in the heating furnace. The high-temperature reaction raw material S-3 and high-temperature air S-4 enter the double membrane reactor 2 through the reaction raw material inlet and the air inlet respectively. The reaction pressure is 240 kPa. The oxygen permeable membrane 3 separates oxygen from the air and enters the reaction zone to react with hydrogen to provide the heat required for dehydrogenation, and simultaneously supplies the heat required for the propane dehydrogenation reaction and removes hydrogen from the reaction system. The hydrogen permeable membrane 4 uses the hydrogen partial pressure difference between the reaction zone and the permeation side to separate the hydrogen to obtain high-purity hydrogen, with an output of 15600 Nm 3 / h.

[0040] Oxygen permeable membrane 3 is Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O3-δ / Sm 0.5 Sr 0.5 CoO 3-δ Oxygen permeable membrane.

[0041] The hydrogen permeable membrane 4 is a Pd-Cu alloy membrane.

[0042] The hydrogen permeable membrane 4 is operated in vacuum with a pressure of 20 kPa.

[0043] The single-pass propane conversion rate of double membrane reactor 2 is 44.6%, and the propylene selectivity is 90.72%. Operating conditions of the separation process: the reaction product is quickly cooled to 300°C to avoid cracking of propane and propylene, and the cooled gas is compressed to 1.40MPa using a multi-stage compressor with an intercooler. The compressed gas enters the cold box system and is cooled to -95°C by ethylene-propylene cascade refrigeration. The light component gas rich in hydrogen will be separated from the liquefied hydrocarbons. The hydrogen-rich gas is partially sent to the dehydrogenation reactor and the selective hydrogenation reactor, and the remaining gas is sent to the combustion furnace for combustion to generate heat. The liquid hydrocarbons are sent to the deethanizer to remove ethane and ethylene, and the liquid at the bottom of the deethanizer is sent to the selective hydrogenation reactor to convert propyne and other substances formed in the side reaction into propylene. The export product is sent to a propane-propylene distillation tower to obtain a 99.5 wt% propylene product, and the unconverted propane at the bottom of the tower is recovered and sent to the dehydrogenation reactor (specific operation reference: Qin J, Pei C, Zhao C, et al. Techno-economic analysis of a hybrid process for propylene and ammonia production [J]. ACS Sustainable Chemistry & Engineering, 2022, 10 (21): 6999-7009). Propylene selectivity and carbon three recovery rate are improved at the same time, and the propane raw material consumption is 587,000 tons / year. Due to the in-situ heating of hydrogen combustion, the overall temperature of the reactor is between 600 and 650 ° C, maintaining a high propane dehydrogenation reaction rate. The single-pass propane conversion rate of the double-membrane reactor is improved, the propane circulation volume is only 2068kmol / h, the required catalyst dosage is 85.2t, and the reduced circulation volume of propane and diluted hydrogen leads to a reduction in the processing capacity of each operating unit. The compression energy consumption is 12.1MW, the reaction preheating load is 232.6GJ / h, and the cryogenic load is 49.2GJ / h.

[0044] Table 1 Comparison of reaction and separation data of different reactor types

[0045] Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Reactor Type Double membrane reactor Oxygen permeable membrane reactor Hydrogen permeable membrane reactor Traditional reactor Propane conversion rate (%) 44.8 42.4 39.1 35.8 Propylene selectivity (%) 90.72 90.33 90.92 90.65 Propane raw material consumption (kt / a) 587 595 591 606 Catalyst dosage (t) 85.2 90.0 96.9 105.8 Compression energy consumption (MW) 12.1 15.0 14.5 18.4 Reaction preheating load (GJ / h) 232.6 239.1 263.3 272.9 Cryogenic load (GJ / h) 49.2 52.0 56.2 62.5

[0046] Table 1 shows a detailed comparison of various reaction-separation data of Example 1 with Comparative Examples 1, 2 and 3. From these data, it can be clearly observed that, compared with the three types of reactors in the comparative examples, the propane conversion rate of the double membrane reactor of Example 1 is increased by 2.4% to 9.0%, while maintaining a high propylene selectivity, the propane raw material consumption is reduced by 0.7% to 3.1%, the catalyst dosage is reduced by 5.3% to 19.5%, the compression energy consumption is reduced by 19.3% to 34.4%, the reaction preheating load is reduced by 2.7% to 14.8%, and the cryogenic load is reduced by 5.4% to 21.3%.

[0047] Figure 3 This is a comparison chart of the enhanced effect of oxygen-hydrogen permeable dual membrane synergistic coupling on propane conversion rate. It can be seen that the propane conversion rate of the dual membrane reactor is generally higher than that of the oxygen permeable membrane reactor, the hydrogen permeable membrane reactor and the traditional reactor. Moreover, as the reaction proceeds, the difference in propane conversion rate gradually widens.

[0048] Figure 4 This is a comparison chart of the enhanced effect of oxygen-hydrogen permeable double membrane synergistic coupling on reaction temperature. It can be seen that the reaction temperature of the double membrane reactor is higher than that of the oxygen permeable membrane reactor, the traditional reactor and the hydrogen permeable membrane reactor. The double membrane reactor separates oxygen through the oxygen permeable membrane to supply heat for hydrogen combustion, effectively suppressing the temperature drop caused by the strong endothermic effect of the dehydrogenation reaction, and cooperates with the hydrogen permeable membrane to separate and efficiently remove hydrogen to achieve the highest reaction temperature among the four types of reactors.

[0049] Comparative Example 1:

[0050] For a propylene unit with an annual output of 500,000 tons, an oxygen permeable membrane reactor for propane dehydrogenation is set up, and the reaction raw materials and air feed, reaction operating conditions, oxygen permeable membrane operating conditions, and separation process operating conditions are the same as those in Example 1. The oxygen permeable membrane separates oxygen from the air and enters the reaction zone to react with hydrogen to provide the heat required for dehydrogenation.

[0051] The single-pass propane conversion rate of the oxygen permeable membrane reactor is 42.3%, and the propylene selectivity is 90.33%. The carbon three recovery rate is improved, and the propane raw material consumption is 595,000 tons / year. Due to the in-situ heating of hydrogen combustion, the overall temperature of the reactor is between 600 and 650°C, maintaining a high propane dehydrogenation reaction rate. The single-pass propane conversion rate of the oxygen permeable membrane reactor is improved, the propane circulation volume is 2263kmol / h, the required catalyst dosage is 90.0t, and the circulation volume of propane and diluted hydrogen is reduced, resulting in a reduction in the processing volume of each operating unit. The compression energy consumption is 15.0MW, the reaction preheating load is 239.1GJ / h, and the cryogenic load is 52.0GJ / h.

[0052] Comparative Example 2:

[0053] For a propylene unit with an annual output of 500,000 tons, a hydrogen permeable membrane reactor for propane dehydrogenation was set up. The reaction raw materials, reaction operating conditions, hydrogen permeable membrane operating conditions, and separation process operating conditions were the same as those in Example 1. The hydrogen permeable membrane uses the hydrogen partial pressure difference between the reaction zone and the permeation side to separate hydrogen to obtain high-purity hydrogen, with an output of 21200Nm 3 / h.

[0054] The permeable hydrogen membrane reactor has a single-pass propane conversion rate of 39.1% and a propylene selectivity of 90.92%. Due to the increase in propylene selectivity and carbon three recovery rate, the propane raw material consumption is 591,000 tons / year. The permeable hydrogen membrane reactor has a single-pass propane conversion rate of 2569 kmol / h, the required catalyst dosage is 96.9t, and the reduced circulation volume of propane and diluted hydrogen leads to a reduction in the processing volume of each operating unit. The compression energy consumption is 14.5MW, the reaction preheating load is 263.3GJ / h, and the cryogenic load is 56.2GJ / h. Comparative Example 3:

[0055] For a 500,000 ton propylene plant per year, a conventional reactor for propane dehydrogenation was set up. The reaction raw material conditions and separation process operating conditions were the same as those in Example 1. The feed pressures were 270 kPa, 260 kPa, 250 kPa, and 240 kPa, respectively. The preheating temperatures were 636°C, 647°C, 646°C, and 641°C, respectively. The reactor mass space velocity was 2 h -1 (References for specific operations: Jowkary H, Farsi M, Rahimpour M R. Supporting the propane dehydrogenation reactors byhydrogen permselective membrane modules to produce ultra-pure hydrogen andincreasing propane conversion: Process modeling and optimization[J]. International Journal of Hydrogen Energy, 2020, 45(12):7364-7373).

[0056] The single-pass propane conversion rate of the conventional reactor is 35.8%, and the propylene selectivity is 90.65%. The propane raw material consumption is 606,000 tons / year, the propane circulation volume is 2937 kmol / h, and the required catalyst dosage is 105.8t. The compression energy consumption required for the separation process is 18.4MW, the reaction preheating load is 272.9GJ / h, and the cryogenic load is 62.5GJ / h.

[0057] Embodiment 2:

[0058] For the 500,000 ton per year propylene plant, a hydrogen-consuming self-heating double membrane reactor for propane dehydrogenation was established. Figure 1 The process is shown. The feed rate of air S-1 is 4450 kmol / h, the reaction raw material S-2 includes 2615 kmol / h propane and 1835 kmol / h diluted hydrogen, and the purge gas S-3 uses water vapor with a feed rate of 4450 kmol / h. After being heated to 650°C in a heating furnace, high-temperature air S-4, high-temperature reaction raw material S-5, and high-temperature purge gas S-6 enter the double membrane reactor 2 through the reaction raw material inlet, air inlet, and purge gas inlet respectively. The reaction pressure is 240 kPa. The oxygen permeable membrane 3 separates oxygen from the air and enters the reaction zone to react with hydrogen to provide the heat required for dehydrogenation, and simultaneously supplies the heat required for propane dehydrogenation reaction and removes hydrogen from the reaction system. The hydrogen permeable membrane 4 separates hydrogen by utilizing the hydrogen partial pressure difference between the reaction zone and the permeation side. After purification, the hydrogen output reaches 19100 Nm 3 / h.

[0059] Oxygen permeable membrane 3 is Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ / Sm 0.5 Sr 0.5 CoO 3-δ Oxygen permeable membrane.

[0060] The hydrogen permeable membrane 4 is a Pd-Cu alloy membrane.

[0061] The hydrogen permeable membrane 4 adopts a purge operation, and the purge gas is 120kPa water vapor. The single-pass propane conversion rate of the double membrane reactor 2 is 45.8%, and the propylene selectivity is 90.51%. The carbon three recovery rate is also improved, and the propane raw material consumption is 603,000 tons / year. Due to the in-situ heating of hydrogen combustion and steam heat exchange, the overall temperature of the reactor is between 600 and 650°C, maintaining a high propane dehydrogenation reaction rate. The single-pass propane conversion rate of the double membrane reactor is improved, the propane circulation volume is only 1937kmol / h, the required catalyst dosage is 83.9t, and the circulation volume of propane and diluted hydrogen is reduced, resulting in a reduction in the processing capacity of each operating unit. The compression energy consumption is 12.3MW, the reaction preheating load is 229.5GJ / h, and the cryogenic load is 47.5GJ / h.

[0062] In summary, through the synergistic coupling enhancement of the oxygen permeable membrane and the hydrogen permeable membrane, the propane conversion rate reaches more than 44%, and the propylene selectivity exceeds 90.5%. The propane dehydrogenation reactor of the present invention breaks through the reaction equilibrium limitation of the traditional reactor.

Claims

1. A propane dehydrogenation double membrane reactor consuming hydrogen and providing self-heating, characterized in that: The reaction zone is equipped with both an oxygen permeable membrane and a hydrogen permeable membrane; The reaction zone is used for carrying out propane dehydrogenation reaction; The oxygen permeable membrane is used to separate oxygen from the air and enter the reaction zone to burn hydrogen for heat supply; A hydrogen permeable membrane is used to remove excess hydrogen from the reaction zone after combustion.

2. The hydrogen-consuming self-heating propane dehydrogenation double membrane reactor according to claim 1, characterized in that: The oxygen permeable membrane and hydrogen permeable membrane are at least one of a tubular membrane, a hollow fiber membrane, and a flat membrane.

3. The hydrogen-consuming self-heating propane dehydrogenation double membrane reactor according to claim 1, characterized in that: The oxygen permeable membrane is a ceramic membrane that conducts electrons and oxygen ions simultaneously.

4. The hydrogen-consuming self-heating propane dehydrogenation double membrane reactor according to claim 1, characterized in that: The hydrogen permeable membrane is a silicon dioxide membrane, a carbon membrane or a palladium membrane.

5. The hydrogen-consuming self-heating propane dehydrogenation double membrane reactor according to claim 1, characterized in that: The heater heats the membrane reactor feed to 400-800°C.

6. The hydrogen-consuming self-heating propane dehydrogenation double membrane reactor according to claim 1, characterized in that: The reaction pressure of the membrane reactor is 10-800 kPa.

7. The hydrogen-consuming self-heating propane dehydrogenation double membrane reactor according to claim 1, characterized in that: The device also includes a reaction raw material inlet, a reaction product outlet, an air inlet, an oxygen-depleted air outlet, a purge gas inlet, a hydrogen-containing gas outlet, a heater, and a shell.

8. The hydrogen-consuming self-heating propane dehydrogenation double membrane reactor according to claim 1, characterized in that: The permeation side of the hydrogen permeable membrane is compatible with both purge operation and vacuum operation. The purge gas is selected from one or a mixture of more than one of the following: water vapor, nitrogen, carbon dioxide, and the vacuum operation pressure range is 10-50 kPa.

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