Full-spectrum solar-assisted system for preparing propylene by oxidative dehydrogenation of propane

Abstract

The invention discloses a system for preparing propylene through propane oxidative dehydrogenation assisted by full-spectrum solar energy, and belongs to the crossing field of new energy and chemical industry. Comprising a photovoltaic photo-thermal integrated system capable of performing full-wave band energy grading utilization on solar energy and generating electric energy and heat energy, a bromine-mediated propane oxidative dehydrogenation system capable of preparing propylene through oxidative dehydrogenation of propane, and an energy conversion device, the energy conversion device can convert heat energy generated by propane combustion and heat energy and electric energy generated by the photovoltaic and photo-thermal integrated system into energy needed by the bromine-mediated propane oxidative dehydrogenation system for preparing propylene through oxidative dehydrogenation of propane, and meanwhile waste heat of the photovoltaic and photo-thermal integrated system and waste heat of the bromine-mediated propane oxidative dehydrogenation system are collected for preparing hot water. A part of electric energy generated by the photovoltaic and photo-thermal integrated system is supplied to the bromine-mediated propane oxidative dehydrogenation system for electrochemical reaction; the bromine-mediated propane oxidative dehydrogenation system produces hydrogen and propylene. Compared with a traditional process, the method has the advantage that the carbon emission cost is obviously reduced by 42.8%.

Description

Technical Field

[0001] This invention relates to the field of interdisciplinary technology of chemical engineering and new energy, and in particular to a system for the production of propylene from propane by full-spectrum solar-assisted oxidative dehydrogenation. Background Technology

[0002] Currently, the industrial production of propylene from propane dehydrogenation mainly relies on traditional steam cracking and direct dehydrogenation processes, which generally suffer from high energy consumption and significant carbon emissions. A typical naphtha steam cracking process requires operation at temperatures of 800-900℃, consuming more than 8% of the petrochemical industry's total primary energy demand while also generating significant carbon emissions. Furthermore, direct dehydrogenation is constrained by thermodynamic equilibrium, is prone to carbon buildup at high temperatures, requires frequent catalyst regeneration, and typically has an operating cycle of less than 24 hours, impacting production efficiency and economics. Compared to direct dehydrogenation, oxidative dehydrogenation can reduce energy consumption by 45%. However, oxidative dehydrogenation still faces engineering challenges such as long-term operational stability, particularly in maintaining propylene selectivity, which requires further optimization.

[0003] To fundamentally address the aforementioned issues, the strategy of replacing traditional fossil fuels with renewable energy is becoming a research hotspot. However, existing solar thermal chemical systems generally suffer from a key technological bottleneck: poor spectral matching. Specifically, this manifests as a failure to fully consider the differences in energy characteristics of solar radiation across different wavelengths, resulting in low utilization efficiency of the solar spectrum. This technological limitation directly affects the overall performance of the system, constraining the economic viability and feasibility of solar-driven chemical production. Further optimization and upgrades are needed to address these problems and provide entirely new solutions for the green production of propylene. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a system for the production of propylene from propane by full-spectrum solar-assisted oxidative dehydrogenation. By rationally configuring the system equipment and coordinating the full-spectrum utilization of solar energy, the system can improve the utilization efficiency of solar energy, thereby solving the problems of high energy consumption, high emissions and insufficient full-spectrum utilization of solar energy in the current propylene production process.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A system for producing propylene from propane using full-spectrum solar energy-assisted oxidative dehydrogenation includes a photovoltaic-thermal integrated system capable of utilizing solar energy across the entire wavelength range to generate electricity and heat, a bromine-mediated propane oxidative dehydrogenation system capable of producing propylene from propane, and an energy conversion device. The energy conversion device converts the heat energy generated from propane combustion, as well as the heat and electricity generated by the photovoltaic-thermal integrated system, into the energy required for the bromine-mediated propane oxidative dehydrogenation system to produce propylene. Simultaneously, it collects waste heat from the photovoltaic-thermal integrated system and the bromine-mediated propane oxidative dehydrogenation system to prepare hot water. A portion of the electricity generated by the photovoltaic-thermal integrated system supplies the energy required for the electrochemical reaction in the bromine-mediated propane oxidative dehydrogenation system. The bromine-mediated propane oxidative dehydrogenation system produces hydrogen and propylene.

[0007] A further improvement of the technical solution of the present invention is that: the energy conversion device includes a propane-burning boiler, a first heat exchanger, an electric refrigeration device, and a second heat exchanger; the first heat exchanger converts the heat generated by the photovoltaic-thermal integrated system and the heat generated by the boiler burning propane into the energy required for heating the stream in the bromine-mediated propane oxidative dehydrogenation system and the energy required for the distillation column; the electric refrigeration device converts a portion of the electrical energy produced by the photovoltaic-thermal integrated system into cold energy to supply the energy required for cooling the stream in the bromine-mediated propane oxidative dehydrogenation system and the energy required for the distillation column; the second heat exchanger converts the waste heat produced by the photovoltaic-thermal integrated system into hot water.

[0008] A further improvement of the technical solution of the present invention is that: the boiler converts water into steam by burning propane to output heat; both the first heat exchanger and the second heat exchanger are shell-and-tube heat exchangers to realize energy transfer between fluids; the electric refrigeration device utilizes an electric-driven cold cycle, is applicable to a temperature range of -40℃ to 10℃, and outputs cold energy.

[0009] A further improvement of the technical solution of the present invention is that: the photovoltaic-thermal integrated system includes a concentrator as the core supporting structure, a spectral frequency division film disposed at the front end of the light-incident side of the concentrator, a photovoltaic panel disposed at the focal line position of the concentrator, and a vacuum tube arranged parallel above the photovoltaic panel; a heat-absorbing plate is tightly attached to the bottom of the photovoltaic panel; an insulator is wrapped around the outside of the photovoltaic panel and the heat-absorbing plate; two copper tubes are disposed in the middle of the heat-absorbing plate as internal heat-conducting medium flow channels to carry away the heat absorbed by the heat-absorbing plate for the generation of hot water; the concentrator adopts a parabolic trough structure to focus transmitted light onto the photovoltaic panel and guide reflected light to the vacuum tube.

[0010] A further improvement of the technical solution of the present invention is that: a spectral frequency division film is covered in front of the concentrator, and the solar irradiance is divided by the spectral frequency division film. The full solar spectrum is divided into specified solar radiation transmission and reflection wavelength ranges. The effective wavelength range spectrum is transmitted to the photovoltaic panel, and the ineffective wavelength range spectrum is reflected to the vacuum tube for heat collection. The vacuum tube is responsible for converting the solar energy in the ineffective wavelength range into heat energy and transferring it. The inside of the vacuum tube is coated with a high-efficiency heat-absorbing coating, which can absorb the ineffective wavelength range spectrum reflected by the spectral frequency division film and convert it into heat energy.

[0011] A further improvement of the technical solution of the present invention is that: the photovoltaic panel adopts a monocrystalline silicon cell or a polycrystalline silicon cell; the spectral response range of the monocrystalline silicon cell is 300-1100nm, and the photoelectric conversion efficiency is 24.4%; the spectral response range of the polycrystalline silicon cell is 350-1000nm, and the photoelectric conversion efficiency is 20.4%.

[0012] A further improvement of the technical solution of the present invention is that: the bromine-mediated propane oxidative dehydrogenation system includes a bromination reactor for bromination, a hydrogenation reactor for hydrogenation, a dehydrogenation reactor for dehydrogenation, an electrochemical reactor for bromine regeneration, a first distillation column, a second distillation column, and connecting pipelines; the bromine-mediated propane oxidative dehydrogenation system uses bromine as an oxidant and a circulating medium to produce propylene from propane through bromination, hydrogenation, dehydrogenation, and bromine regeneration, while simultaneously producing hydrogen, and recovering waste heat during the process.

[0013] A further improvement to the technical solution of this invention is as follows: the reaction process of bromine and propane in the bromine-mediated propane oxidative dehydrogenation system is as follows: bromine and propane are mixed and then fed into a bromination reactor for bromination. The resulting monobromopropane, hydrogen bromide, dibromopropane, and unconverted propane are the first reaction products. After cooling, the first reaction products are separated in a first distillation column. The resulting dibromopropane is mixed with hydrogen and then fed into a hydrogenation reactor for hydrogenation, producing monobromopropane. The unreacted propane from the first distillation column is recycled back to the bromination reactor for bromination. The separated monobromopropane is heated and then fed into a dehydrogenation reactor for dehydrogenation, producing propylene and hydrogen bromide as the second reaction products. After cooling, the second reaction products are further separated in a second distillation column to obtain high-purity propylene. The unreacted monobromopropane is recovered and recycled into the dehydrogenation reactor for dehydrogenation. The hydrogen bromide separated from the first and second distillation columns is fed into an electrochemical reactor for bromine regeneration, producing hydrogen and bromine to achieve bromine recycling.

[0014] A further improvement of the technical solution of the present invention is that: in the bromination reaction, the pretreated propane reacts with bromine at 250℃-350℃ and 1bar-30bar; the bromination reactor is made of corrosion-resistant material and has a built-in multi-stage temperature control module;

[0015] In the hydrogenation reaction, dibromopropane is mixed with electrolytically regenerated hydrogen and reacted at 350°C and 30 bar. The hydrogenation reactor is a fixed-bed reactor packed with a Pd / Al2O3 catalyst.

[0016] In the dehydrogenation reaction, monobromopropane, preheated to 400°C, reacts at 400°C and 20 bar under the action of a Cr2O3-Al2O3 catalyst.

[0017] In the bromine regeneration reaction, hydrogen bromide is heated to 300°C and then enters the electrochemical reactor. The bromine produced by electrolysis is liquefied and then reintroduced into the bromination reactor. The hydrogen produced is supplied to the hydrogenation reactor. The electrochemical reactor is coupled with the photovoltaic-thermal integrated system.

[0018] A further improvement of the technical solution of the present invention is that the reaction process of bromine and propane in the bromine-mediated propane oxidative dehydrogenation system also includes a waste heat recovery process to recover and utilize the waste heat in the high-temperature reaction and separation process. Specifically, the process is as follows: the first condenser of the first distillation column and the propane stream before the bromination reactor exchange heat; the reboiler of the first distillation column and the second condenser of the second distillation column exchange heat directly; the mixed stream after the bromination reaction and the bromine stream exchange heat between the streams; and the mixed stream after the dehydrogenation reactor and the hydrogen bromide stream after the second distillation column exchange heat between the streams.

[0019] The technological advancements achieved by this invention due to the adoption of the above technical solutions are as follows:

[0020] 1. This invention combines a photovoltaic-thermal integrated system, an energy conversion device, and a bromine-mediated propane oxidative dehydrogenation system. It utilizes spectral frequency division technology to achieve cascaded utilization of solar energy across the entire wavelength range. The photovoltaic layer converts electricity to drive the system's operation, while the photothermal layer provides process heat. The bromine-mediated reaction system employs a closed-loop design, efficiently producing propylene through four stages: bromination, hydrogenation, dehydrogenation, and bromine regeneration. Combined with waste heat recovery, it maximizes energy recovery. Compared to traditional processes, it significantly reduces carbon emission costs by 42.8%, demonstrating stronger competitiveness under carbon constraints. Simultaneously, it produces high-purity hydrogen and hot water as byproducts, resulting in significant environmental and economic benefits.

[0021] 2. The full-spectrum solar-assisted propane oxidative dehydrogenation to propylene system provided by this invention significantly reduces energy consumption, production costs, and carbon emissions by fully utilizing solar energy. The separation and recycling of products in the system achieves full resource utilization, reduces waste emissions, and meets the requirements of green and sustainable development. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a system for producing propylene from propane using full-spectrum solar-assisted oxidative dehydrogenation provided in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the photovoltaic-thermal integrated system in an embodiment of the present invention;

[0025] Among them, 1. Photovoltaic-thermal integrated system; 1-1. Vacuum tube; 1-2. Spectral frequency division film; 1-3. Concentrator; 1-4. Photovoltaic panel; 1-5. Heat absorber plate; 1-6. Copper tube; 1-7. Insulating plate; 2. Bromine-mediated propane oxidative dehydrogenation system; 2-1. Bromination reactor; 2-2. Hydrogenation reactor; 2-3. Dehydrogenation reactor; 2-4. Electrochemical reactor; 2-5. First distillation column; 2-6. Second distillation column; 3. Boiler; 4. First heat exchanger; 5. Electric refrigeration device; 6. Second heat exchanger. Detailed Implementation

[0026] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0028] like Figure 1As shown, a system for the production of propylene from propane using full-spectrum solar-assisted propane oxidative dehydrogenation is a propane oxidative dehydrogenation system coupled with full-spectrum solar energy utilization. It achieves efficient and low-carbon production of propylene through photothermal synergistic catalysis, including a photovoltaic-photothermal integrated system 1, a bromine-mediated propane oxidative dehydrogenation system 2, an energy conversion device, and various connecting pipelines.

[0029] The photovoltaic-thermal integrated system 1 can utilize solar energy across the entire wavelength range and generate electrical and thermal energy; a portion of the electrical energy generated by the photovoltaic-thermal integrated system 1 supplies the energy required for the electrochemical reaction in the bromine-mediated propane oxidative dehydrogenation system 2.

[0030] Bromine-mediated propane oxidative dehydrogenation system 2 can oxidize and dehydrogenate propane to produce propylene, while simultaneously producing hydrogen.

[0031] The energy conversion device can convert the heat energy generated by propane combustion and the heat and electricity generated by the photovoltaic-thermal integrated system 1 into the energy required for the bromine-mediated propane oxidative dehydrogenation system 2 to oxidize and dehydrogenate propane to produce propylene. At the same time, it can collect the waste heat of the photovoltaic-thermal integrated system 1 and the bromine-mediated propane oxidative dehydrogenation system 2 to prepare hot water.

[0032] Furthermore, the energy conversion device includes a propane-burning boiler 3, a first heat exchanger 4, an electric refrigeration device 5, and a second heat exchanger 6; the first heat exchanger 4 converts the heat generated by the photovoltaic-thermal integrated system 1 and the heat generated by the propane-burning boiler 3 into the energy required for heating the stream in the bromine-mediated propane oxidative dehydrogenation system 2 and the energy required for the distillation towers (including the first distillation tower 2-5 and the second distillation tower 2-6); the electric refrigeration device 5 converts a portion of the electrical energy produced by the photovoltaic-thermal integrated system 1 into cold energy to supply the energy required for cooling the stream in the bromine-mediated propane oxidative dehydrogenation system 2 and for the distillation towers; the second heat exchanger 6 converts the waste heat produced by the photovoltaic-thermal integrated system 1 into hot water.

[0033] Furthermore, boiler 3 converts water into steam by burning propane to output heat; the first heat exchanger 4 and the second heat exchanger 6 are both shell and tube heat exchangers to realize energy transfer between fluids; the electric refrigeration device 5 uses electric power to drive a cold cycle, and is applicable to a temperature range of -40℃ to 10℃, outputting cold energy.

[0034] Furthermore, such as Figure 2As shown, the photovoltaic-thermal integrated system 1 includes a concentrator 1-3 as the core supporting structure, a spectral frequency division film 1-2 located at the front end of the light-incident side of the concentrator 1-3 (specifically, it is detachably connected to the concentrator 1-3 by bolts for easy maintenance and replacement), a photovoltaic panel 1-4 located at the focal line position of the concentrator 1-3, and a vacuum tube 1-1 arranged parallel above the photovoltaic panel 1-4; a heat absorber plate 1-5 is tightly attached below the photovoltaic panel 1-4; an insulator 1-7 is wrapped around the outside of the photovoltaic panel 1-4 and the heat absorber plate 1-5; two copper tubes 1-6 are arranged in the middle of the heat absorber plate 1-5 as internal heat conduction medium circulation channels to carry away the heat absorbed by the heat absorber plate 1-5 for the generation of hot water. The concentrator 1-3 adopts a parabolic trough structure to focus the transmitted light to the photovoltaic panel 1-4, while guiding the reflected light to the vacuum tube 1-1.

[0035] Insulators 1-7 are used to reduce heat loss in the system and improve energy utilization efficiency. In the photovoltaic-thermal integrated system 1, insulators 1-7 are made of thermal insulation material, and their function is to prevent the heat generated by photovoltaic panels 1-4 and heat absorber panels 1-5 from diffusing to the external environment, thereby reducing heat loss caused by heat conduction, heat radiation and heat convection.

[0036] The function of the heat absorber plate 1-5 is to absorb heat. When the photovoltaic panel 1-4 absorbs light energy to generate electricity, it will generate a lot of heat due to energy loss in the photoelectric conversion process. If the heat accumulates and the temperature of the photovoltaic panel 1-4 becomes too high, it will significantly reduce its photoelectric conversion efficiency. The heat absorber plate 1-5 is closely attached to the bottom of the photovoltaic panel 1-4 and can quickly absorb the excess heat generated by the photovoltaic panel 1-4.

[0037] Furthermore, a spectral divider film 1-2 is placed in front of the concentrator 1-3. Solar irradiance is divided by the spectral divider film 1-2, separating the full solar spectrum into specified wavelength ranges for transmission and reflection. The effective wavelength range is transmitted to the photovoltaic panel 1-4, while the ineffective wavelength range is reflected to the vacuum tube 1-1 for heat collection. Therefore, usable energy from sunlight can be effectively separated and used for power generation and thermochemical applications. The vacuum tube 1-1 is responsible for converting and transferring solar energy in the ineffective wavelength range. The interior of the vacuum tube 1-1 is coated with a high-efficiency heat-absorbing coating, which absorbs the ineffective wavelength range reflected by the spectral divider film 1-2 and converts it into heat energy. The high-temperature heat energy is transported through the pipe structure of the vacuum tube 1-1 to subsequent systems such as the energy conversion device to drive reactions such as propane oxidative dehydrogenation.

[0038] Furthermore, photovoltaic panels 1-4 mainly use crystalline silicon cells, which can be selected as monocrystalline silicon cells or polycrystalline silicon cells; the spectral response range of monocrystalline silicon cells is 300-1100nm, and the photoelectric conversion efficiency is 24.4%; the spectral response range of polycrystalline silicon cells is 350-1000nm, and the photoelectric conversion efficiency is 20.4%.

[0039] Furthermore, the bromine-mediated propane oxidative dehydrogenation system 2 includes a bromination reactor 2-1 for bromination, a hydrogenation reactor 2-2 for hydrogenation, a dehydrogenation reactor 2-3 for dehydrogenation, an electrochemical reactor 2-4 for bromine regeneration, a first distillation column 2-5, a second distillation column 2-6, and various connecting pipelines. The bromine-mediated propane oxidative dehydrogenation system 2 uses bromine as an oxidant and circulating medium to produce propylene through bromination, hydrogenation, dehydrogenation, and bromine regeneration reactions, while simultaneously producing hydrogen gas, and recovering waste heat during the process.

[0040] Furthermore, the reaction process of bromine and propane in bromine-mediated propane oxidative dehydrogenation system 2 is as follows:

[0041] (1) After bromine is mixed with propane, it enters the bromination reaction stage. The propane stream and the bromine stream react in bromination reactor 2-1. The reaction equation is as follows:

[0042] C3H8 + Br2 → C3H7Br + HBr

[0043] C3H7Br + Br2 → C3H6Br2 + HBr

[0044] The reaction is thermally induced and mainly produces hydrogen bromide, monobromopropane and dibromopropane. The reaction is carried out at a moderate temperature of 250℃-350℃ and a pressure of 1 bar-30 bar.

[0045] (2) The mixed stream generated during the bromination reaction stage consists of monobromopropane, hydrogen bromide, dibromopropane, and unconverted propane. The reaction products are separated by the first distillation column 2-5 after cooling.

[0046] (3) The dibromopropane stream obtained from the first distillation column 2-5 is mixed with hydrogen and then enters the hydrogenation reaction stage. The dibromopropane and hydrogen react in the hydrogenation reactor 2-2. The reaction equation is as follows:

[0047]

[0048] The reaction was carried out in a hydrogenation reactor 2-2 (a fixed-bed reactor packed with Pd / Al2O3 catalyst) at 350℃ and 30 bar. The reaction produced monobromopropane and hydrogen bromide with a conversion rate of over 95% and a selectivity of over 98%.

[0049] (4) In the hydrogenation reaction stage, monobromopropane is produced. The monobromopropane stream re-enters the first distillation column 2-5 for separation. The unreacted propane stream from the first distillation column 2-5 is recycled back to the bromination reaction stage. The monobromopropane stream separated from the first distillation column 2-5 is heated and then sent to the dehydrogenation reaction stage. The monobromopropane reacts in the dehydrogenation reactor 2-3. The reaction equation is as follows:

[0050]

[0051] 1,000 bromopropane reacts with Cr2O3-Al2O3 catalyst at 400 ℃ and 20 bar to produce propylene and hydrogen bromide. The single-pass reaction efficiency can reach more than 70%. The product is separated by the first distillation column 2-5 and then recycled for further reaction. The reaction efficiency can reach more than 90%.

[0052] (5) The mixed stream of reaction products in the dehydrogenation reaction stage contains propylene, hydrogen bromide, and unreacted monobromopropane. After cooling, the mixed stream is further separated in the second distillation column 2-6 to obtain high-purity propylene.

[0053] (6) The unreacted monobromopropane stream separated from the second distillation column 2-6 is recycled into the dehydrogenation reactor 2-3 for dehydrogenation reaction;

[0054] (7) The hydrogen bromide separated from the first distillation column 2-5 and the second distillation column 2-6 is fed into the electrochemical reactor 2-4 for bromine regeneration. The hydrogen bromide undergoes a reaction in the electrochemical reactor 2-4, and the reaction equation is as follows:

[0055]

[0056] After mixing, hydrogen bromide was electrolyzed in electrochemical reactor 2-4 at 300℃ and 20 bar, where all hydrogen bromide was converted into hydrogen and bromine. The energy required for the decomposition of hydrogen bromide was estimated based on the thermodynamic Gibbs free energy, as follows:

[0057] ΔG=n·F·ΔE

[0058] In the formula, n represents the number of moles of electrons required per mole of product; F represents the Faraday constant; and ΔE is the theoretical electrode potential.

[0059] (8) Hydrogen and bromine are produced in electrochemical reactor 2-4. The bromine is recycled into bromination reactor 2-1 for bromination reaction, thus realizing the cycle.

[0060] In the process flow of the bromine-mediated propane oxidative dehydrogenation system 2, a waste heat recovery process is also included to recover and utilize the waste heat from the high-temperature reaction and separation process. Specifically, it can be described as follows: the first condenser of the first distillation column 2-5 exchanges heat with the propane stream before the bromination reactor 2-1; the reboiler of the first distillation column 2-5 exchanges heat directly with the second condenser of the second distillation column 2-6; the mixed stream after the bromination reaction exchanges heat with the bromine stream; and the mixed stream after the dehydrogenation reactor 2-3 exchanges heat with the hydrogen bromide stream after the second distillation column 2-6.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for the full-spectrum solar-assisted oxidative dehydrogenation of propane to propylene, characterized in that: The system includes a photovoltaic-thermal integrated system (1) capable of utilizing solar energy across the entire wavelength range to generate electricity and heat, a bromine-mediated propane oxidative dehydrogenation system (2) capable of oxidizing and dehydrogenating propane to propylene, and an energy conversion device. The energy conversion device can convert the heat energy generated by propane combustion and the heat and electricity generated by the photovoltaic-thermal integrated system (1) into the energy required by the bromine-mediated propane oxidative dehydrogenation system (2) to oxidize and dehydrogenate propane to propylene, while collecting the waste heat from the photovoltaic-thermal integrated system (1) and the bromine-mediated propane oxidative dehydrogenation system (2) to prepare hot water. A portion of the electricity generated by the photovoltaic-thermal integrated system (1) is supplied to the energy required for the electrochemical reaction in the bromine-mediated propane oxidative dehydrogenation system (2). The bromine-mediated propane oxidative dehydrogenation system (2) produces hydrogen and propylene.

2. The system for producing propylene from propane using full-spectrum solar-assisted oxidative dehydrogenation according to claim 1, characterized in that: The energy conversion device includes a propane-burning boiler (3), a first heat exchanger (4), an electric refrigeration device (5), and a second heat exchanger (6); the first heat exchanger (4) converts the heat generated by the photovoltaic-thermal integrated system (1) and the heat generated by the boiler (3) burning propane into the energy required for heating the stream in the bromine-mediated propane oxidative dehydrogenation system (2) and the energy required for the distillation column; the electric refrigeration device (5) converts a portion of the electrical energy produced by the photovoltaic-thermal integrated system (1) into cold energy to supply the energy required for cooling the stream in the bromine-mediated propane oxidative dehydrogenation system (2) and the distillation column; the second heat exchanger (6) converts the waste heat produced by the photovoltaic-thermal integrated system (1) into hot water.

3. The system for producing propylene from propane using full-spectrum solar-assisted oxidative dehydrogenation according to claim 2, characterized in that: The boiler (3) converts water into steam by burning propane to output heat; the first heat exchanger (4) and the second heat exchanger (6) are both shell and tube heat exchangers to realize energy transfer between fluids; the electric refrigeration device (5) uses electric drive cold cycle, applicable temperature range is between -40°C and 10°C, and outputs cold energy.

4. The system for producing propylene from propane using full-spectrum solar-assisted oxidative dehydrogenation according to claim 1, characterized in that: The photovoltaic-thermal integrated system (1) includes a concentrator (1-3) as the core supporting structure, a spectral frequency division film (1-2) disposed at the front end of the light-incident side of the concentrator (1-3), a photovoltaic panel (1-4) disposed at the focal line position of the concentrator (1-3), and a vacuum tube (1-1) arranged parallel above the photovoltaic panel (1-4); a heat-absorbing plate (1-5) is tightly attached to the bottom of the photovoltaic panel (1-4); an insulator (1-7) is wrapped around the outside of the photovoltaic panel (1-4) and the heat-absorbing plate (1-5); two copper tubes (1-6) are disposed in the middle of the heat-absorbing plate (1-5) as internal heat-conducting medium flow channels to carry away the heat absorbed by the heat-absorbing plate (1-5) for the generation of hot water; the concentrator (1-3) adopts a parabolic trough structure to focus transmitted light to the photovoltaic panel (1-4) and guide reflected light to the vacuum tube (1-1).

5. The system for producing propylene from propane using full-spectrum solar-assisted oxidative dehydrogenation according to claim 4, characterized in that: The concentrator (1-3) is covered with a spectral divider film (1-2). The solar irradiance is divided by the spectral divider film (1-2), and the full solar spectrum is divided into specified solar radiation transmission and reflection wavelength ranges. The effective wavelength range spectrum is transmitted to the photovoltaic panel (1-4), and the ineffective wavelength range spectrum is reflected to the vacuum tube (1-1) for heat collection. The vacuum tube (1-1) is responsible for converting the solar energy in the ineffective wavelength range into heat energy and transferring it. The inside of the vacuum tube (1-1) is coated with a high-efficiency heat-absorbing coating, which can absorb the ineffective wavelength range spectrum reflected by the spectral divider film (1-2) and convert it into heat energy.

6. The system for producing propylene from propane using full-spectrum solar-assisted oxidative dehydrogenation according to claim 4, characterized in that: The photovoltaic panels (1-4) are made of monocrystalline silicon cells or polycrystalline silicon cells; the spectral response range of the monocrystalline silicon cells is 300-1100nm, and the photoelectric conversion efficiency is 24.4%; the spectral response range of the polycrystalline silicon cells is 350-1000nm, and the photoelectric conversion efficiency is 20.4%.

7. The system for producing propylene from propane using full-spectrum solar-assisted oxidative dehydrogenation according to claim 1, characterized in that: The bromine-mediated propane oxidative dehydrogenation system (2) includes a bromination reactor (2-1) for bromination, a hydrogenation reactor (2-2) for hydrogenation, a dehydrogenation reactor (2-3) for dehydrogenation, an electrochemical reactor (2-4) for bromine regeneration, a first distillation column (2-5), a second distillation column (2-6), and connecting pipelines. The bromine-mediated propane oxidative dehydrogenation system (2) uses bromine as an oxidant and a circulating medium to produce propylene from propane through bromination, hydrogenation, dehydrogenation, and bromine regeneration, while simultaneously producing hydrogen. Waste heat is recovered during the process.

8. The system for producing propylene from propane using full-spectrum solar-assisted oxidative dehydrogenation according to claim 7, characterized in that: The reaction process of bromine and propane in the bromine-mediated propane oxidative dehydrogenation system (2) is as follows: Bromine is mixed with propane and then fed into the bromination reactor (2-1) for bromination. The resulting monobromopropane, hydrogen bromide, dibromopropane, and unreacted propane are the first reaction products. After cooling, the first reaction products are separated in the first distillation column (2-5). The resulting dibromopropane is mixed with hydrogen and then fed into the hydrogenation reactor (2-2) for hydrogenation, producing monobromopropane. The unreacted propane from the first distillation column (2-5) is recycled back to the bromination reactor (2-1) for bromination, and the separated monobromopropane... Propane is heated and fed into the dehydrogenation reactor (2-3) for dehydrogenation reaction. The resulting propylene and hydrogen bromide are the second reaction products. After cooling, the second reaction products are further separated in the second distillation column (2-6) to obtain high-purity propylene. Unreacted monobromopropane is recycled back into the dehydrogenation reactor (2-3) for dehydrogenation reaction. The hydrogen bromide separated from the first distillation column (2-5) and the second distillation column (2-6) is sent into the electrochemical reactor (2-4) for bromine regeneration reaction, producing hydrogen and bromine to achieve bromine recycling.

9. The system for producing propylene from propane using full-spectrum solar-assisted oxidative dehydrogenation according to claim 8, characterized in that: In the bromination reaction, pretreated propane reacts with bromine at 250°C-350°C and 1 bar-30 bar; the bromination reactor (2-1) is made of corrosion-resistant material and has a built-in multi-stage temperature control module; In the hydrogenation reaction, dibromopropane is mixed with electrolytically regenerated hydrogen and reacted at 350°C and 30 bar. The hydrogenation reactor (2-2) is a fixed-bed reactor packed with Pd / Al2O3 catalyst. In the dehydrogenation reaction, monobromopropane, preheated to 400°C, reacts at 400°C and 20 bar under the action of a Cr2O3-Al2O3 catalyst. In the bromine regeneration reaction, hydrogen bromide is heated to 300°C and then enters the electrochemical reactor (2-4). The bromine generated by electrolysis is liquefied and then re-enters the bromination reactor (2-1). The generated hydrogen is supplied to the hydrogenation reactor (2-2). The electrochemical reactor (2-4) is coupled with the photovoltaic-thermal integrated system (1).

10. The system for producing propylene from propane using full-spectrum solar-assisted oxidative dehydrogenation according to claim 8, characterized in that: The reaction process of bromine and propane in the bromine-mediated propane oxidative dehydrogenation system (2) also includes a waste heat recovery process to recover and utilize the waste heat in the high-temperature reaction and separation process. The specific process is as follows: the first condenser of the first distillation column (2-5) and the propane stream before the bromination reactor (2-1) exchange heat; the reboiler of the first distillation column (2-5) and the second condenser of the second distillation column (2-6) exchange heat directly; the mixed stream after the bromination reaction and the bromine stream exchange heat between the streams; and the mixed stream after the dehydrogenation reactor (2-3) and the hydrogen bromide stream after the second distillation column (2-6) exchange heat between the streams.

Images