Green n-isobutyraldehyde separation system and method

Abstract

The invention provides a green n-isobutyraldehyde separation system and a green n-isobutyraldehyde separation method, the separation system comprises an atmospheric tower, a pressurized tower and a flow divider, and the flow divider is connected with the atmospheric tower and the pressurized tower through an atmospheric tower raw material liquid inlet and a pressurized tower raw material liquid inlet respectively. Through efficient heat recovery and unique pipeline design, the energy consumption is remarkably reduced, the separation efficiency is improved, meanwhile, the environmental pollution is reduced, and green separation of n-butyraldehyde and isobutyraldehyde is realized. Compared with the prior art, the invention has obvious progress in the aspects of energy conservation, environmental protection, separation effect and system stability.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical production, and in particular to a green n-isobutyraldehyde separation system and method. Background Art

[0002] In the chemical industry, the separation of n-butyraldehyde and isobutyraldehyde is a key process widely used in industries such as synthetic resins, plastics, and fragrances. Traditional separation methods primarily rely on conventional distillation techniques. However, due to the close boiling points of n-butyraldehyde and isobutyraldehyde, the separation process requires high energy input and suffers from low separation efficiency, leading to high production costs. Furthermore, the large amount of heat wasted in traditional distillation not only increases energy consumption but also exacerbates environmental pollution, contradicting the current trend of green chemical development. To address these issues, existing technologies have attempted to employ methods such as pressurized distillation or azeotropic distillation. However, these methods often suffer from drawbacks such as complex equipment, difficult operation, high energy consumption, or the introduction of additional solvents, which can complicate subsequent processing. For example, while azeotropic distillation can improve separation efficiency, it requires the addition of an entrainer, which not only adds separation steps but also may introduce new pollutants. While simple pressurized distillation can reduce the difference in boiling points, it places high demands on equipment and fails to effectively address the issue of heat recovery. While heat recovery technologies have gained increasing attention in recent years, they still face numerous challenges in practical application, such as low heat transfer efficiency in pipes, insufficient thermal insulation, and susceptibility to corrosion and scaling. Especially under high-temperature and high-pressure conditions, the durability and thermal stability of traditional pipelines often fail to meet long-term operational requirements. Furthermore, existing technologies lack a systematic solution for the comprehensive utilization of heat energy during the separation of n-butyraldehyde and isobutyraldehyde, resulting in low energy efficiency.

[0003] Therefore, developing an efficient, energy-saving and environmentally friendly n-isobutyraldehyde separation system and method has become a technical problem that needs to be solved urgently in this field.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The first objective of the present invention is to provide a green n-butyraldehyde and isobutyraldehyde separation system. Through efficient heat recovery and a unique pipeline design, this system significantly reduces energy consumption, improves separation efficiency, and minimizes environmental pollution, achieving green separation of n-butyraldehyde and isobutyraldehyde. Compared with existing technologies, this system offers significant improvements in energy conservation and environmental protection, separation efficiency, and system stability.

[0006] The second purpose of the present invention is to provide a separation method performed by the above-mentioned green n-butyraldehyde separation system, which realizes the efficient and green separation of n-butyraldehyde and isobutyraldehyde, and provides a new technical path for the sustainable development of chemical production.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted: A green normal-isobutyraldehyde separation system comprises an atmospheric tower, a pressurized tower and a splitter, wherein the splitter is connected to the atmospheric tower and the pressurized tower via a raw liquid inlet of the atmospheric tower and a raw liquid inlet of the pressurized tower respectively; The atmospheric distillation system is connected to the pressurized distillation system via the heat recovery system; the heat recovery system comprises a heat recovery pipeline and an atmospheric tower kettle reboiler and a pressure control valve disposed on the heat recovery pipeline and connected in sequence, the atmospheric tower kettle reboiler being connected to the bottom of the atmospheric tower, and the pressure control valve being connected to the top of the pressurized tower; The heat recovery pipe adopts a double-layer casing structure, the inner pipe is a corrugated pipe, the outer pipe is an insulation jacket, and the two ends of the outer pipe are flange-connected to the atmospheric tower kettle reboiler and the pressure control valve; The space between the inner tube and the outer tube of the heat recovery pipeline is filled with inert gas.

[0008] The present invention provides a green isobutyraldehyde separation system, the core of which is to achieve efficient heat energy utilization between the atmospheric tower and the pressurized tower through a specific heat recovery system, thereby reducing energy consumption and improving separation efficiency. The separation system of the present invention includes an atmospheric tower, a pressurized tower and a splitter, wherein the splitter transports the raw liquid to the atmospheric tower and the pressurized tower respectively for separation, and the heat recovery system transfers the steam heat energy at the top of the pressurized tower to the atmospheric tower kettle reboiler through a heat recovery pipeline with a double-layer casing structure, thereby achieving cascade utilization of energy. The heat recovery pipeline adopts a double-layer structure with an inner tube as a corrugated tube and an outer tube as an insulation jacket, and inert gas is filled between the inner tube and the outer tube. This design not only improves the heat transfer efficiency, but also enhances The stability and safety of the system; the inner wall of the bellows is coated with a hydrophobic-oleophilic composite coating composed of nano-silica particles and fluorinated polymers, which can effectively reduce the fluid flow resistance and prevent scaling, while improving the affinity for organic matter, ensuring the uniformity and efficiency of heat transfer. In addition, thermally conductive ceramic particles are embedded in the troughs of the bellows, which further enhances the thermal conductivity, allowing heat to diffuse quickly and evenly in the pipeline, avoiding local overheating or energy loss; the outer surface of the thermal insulation jacket is covered with a detachable reflective insulation layer composed of multiple layers of aluminum foil and glass fiber cloth alternately stacked. This structure can not only effectively reflect thermal radiation and reduce heat loss, but also facilitates maintenance and replacement, ensuring long-term thermal insulation effect. The pressure control valve adopts an angle regulating valve, and a double valve core structure is provided in the valve body. The upper valve core is connected to the steam outlet of the pressure tower, and the lower valve core is connected to the reboiler of the atmospheric tower kettle. This design can accurately adjust the steam flow and pressure, ensure the stable operation of the heat recovery system, and avoid equipment damage or separation efficiency reduction caused by pressure fluctuations. In addition, in the present invention, the layout and connection mode of the atmospheric tower and the pressure tower are also optimized. The top of the atmospheric tower is provided with a discharge port and a reflux tank inlet. The condenser and the reflux tank are both connected to the isobutyraldehyde storage tank, and the bottom of the tower is connected to the normal butyraldehyde storage tank and the tower kettle reboiler through the discharge port to form a closed loop circulation, ensuring the efficient collection of the separated products and the continuous utilization of energy. The top of the pressure tower is connected to the pressure control valve through the steam outlet, and a buffer reflux tank is provided to stabilize the system pressure. The bottom is externally connected to the reboiler and is connected to the normal butyraldehyde storage tank through the discharge port, further optimizing the thermodynamic efficiency of the separation process.

[0009] Overall, the separation system of the present invention achieves efficient, energy-saving and green separation of n-butyraldehyde and isobutyraldehyde through heat recovery pipeline design, optimized tower layout and precise pressure control, solving the problems of high energy consumption, low efficiency and serious environmental pollution in traditional separation technology, and has significant industrial application value and market prospects. The double-layer sleeve heat recovery structure of the system significantly improves the thermal energy utilization rate, reduces the input of external energy, and reduces production costs; the application of hydrophobic-oleophilic coating and thermally conductive ceramic particles further optimizes the heat transfer process and improves the stability and durability of the system; and the design of the detachable insulation layer and the double-spool pressure control valve enhances the maintainability and operational flexibility of the system, making it more adaptable to the needs of industrial production. In addition, the design concept of closed-loop circulation and energy cascade utilization is in line with the development trend of green chemical industry, reduces waste heat emissions and resource waste, and has significant environmental advantages.

[0010] Preferably, as a further feasible solution, the inner wall of the bellows is coated with a hydrophobic-oleophilic composite coating, which is composed of nano-silica particles and fluorinated polymers, wherein the particle size of the nano-silica particles is 10-50nm and the thickness of the fluorinated polymer is 0.5-2μm.

[0011] The present invention further defines the green n-isobutyraldehyde separation system, specifically relating to a hydrophobic-oleophilic composite coating technology for the inner wall of a heat recovery pipe, wherein the coating is defined as consisting of nano-silica particles and fluorinated polymers, wherein the particle size of the nano-silica particles is controlled within the range of 10-50 nm, and the thickness of the fluorinated polymer is precisely controlled within the range of 0.5-2 μm. The introduction of nano-silica particles first solves the industry problem of easy scaling and corrosion on the inner wall of traditional pipes. Its nanoscale size gives the coating an ultra-high specific surface area and surface activity, and can form a rough structure on a microscopic scale. This structure imitates the bionic principle of the lotus leaf surface, so that the coating exhibits excellent hydrophobic properties, effectively preventing energy loss and corrosion risks caused by condensation of water vapor on the pipe wall; at the same time, the addition of the fluorinated polymer not only serves to bond the nanoparticles, but its low surface energy characteristics further enhance the hydrophobic effect, forming a stable composite coating system.

[0012] More importantly, during the distillation process, the raw liquid and steam contain a large amount of organic components. The inner wall of traditional metal pipes has a poor affinity for these substances, which easily forms a retention layer and hinders heat transfer. The lipophilic properties of the present invention are achieved through the molecular design of the fluorinated polymer. Its fluorinated chain segments can produce specific interactions with organic molecules, promote the wetting and spreading of organic matter on the pipe wall, and thus significantly improve the heat transfer efficiency. The particle size range of nano-silica particles can ensure sufficient surface roughness to obtain a super-hydrophobic effect, and avoid the problem of uneven coating or decreased mechanical strength caused by excessively large particles; the thickness of the fluorinated polymer is controlled at 0.5-2μm to balance the durability and thermal resistance effect of the coating. Too thin will lead to insufficient protection, and too thick may affect heat conduction.

[0013] In addition, the coating technology of the present invention solves multiple bottleneck problems in actual operation. First, under long-term high-temperature and high-pressure working conditions, traditional coatings are prone to peeling, aging and other problems. The present invention, through the synergistic effect of nanoparticles and polymers, makes the coating have excellent heat resistance and mechanical stability; secondly, in the phase change heat transfer process, the wetting characteristics of the tube wall directly affect the condensation heat transfer coefficient. The intelligent hydrophobic-oleophilic design enables the droplets formed by steam condensation to quickly detach from the wall (hydrophobic effect), while the organic matter can be evenly distributed on the wall to form a thin film (oleophilic effect). This dual mechanism improves the heat transfer efficiency; thirdly, the anti-scaling properties of the coating greatly reduce the frequency of cleaning.

[0014] Preferably, as a further feasible solution, heat-conducting ceramic particles are embedded in the troughs of the corrugated pipe of the heat recovery pipe.

[0015] The present invention also embeds thermally conductive ceramic particles in the troughs of the corrugated pipe in the heat recovery pipe. The corrugated pipe itself has superior heat transfer characteristics to ordinary straight pipes due to its unique corrugated structure. The alternating arrangement of its peaks and troughs can effectively disrupt the laminar boundary layer of the fluid, promote the formation of turbulence, and thus enhance heat transfer efficiency. However, the present invention also embeds thermally conductive ceramic particles in the troughs, thereby further breaking through the performance limits of traditional bellows and achieving a step-by-step improvement in heat transfer performance. The selection of thermally conductive ceramic particles in the present invention is not arbitrary, but rather a result of rigorous material screening. They generally have high thermal conductivity, excellent high-temperature stability and chemical inertness, making them particularly suitable for the corrosive environment that may occur during the separation of n-butyraldehyde and isobutyraldehyde. These particles are precisely embedded in the troughs. The selection of this specific location is based on the results of fluid mechanics simulation and experimental verification. Because the troughs are areas with relatively low fluid flow rates and high thermal resistance, introducing high thermal conductivity materials here can most effectively compensate for the weak links in heat transfer of traditional bellows.

[0016] In addition, in the present invention, a solid heat conduction channel is formed by embedding thermally conductive ceramic particles through direct contact between the particles and the metal tube wall, and the thermally conductive ceramic particle array forms an extended heat transfer surface at the trough; in addition, the fluid micro-disturbance effect caused by the gaps between the thermally conductive ceramic particles. These three mechanisms work together to fundamentally solve the "thermal dead corner" problem existing in traditional corrugated tubes.

[0017] Preferably, as a further feasible solution, the outer surface of the insulation jacket of the heat recovery pipe is covered with a detachable reflective insulation layer, and the detachable reflective insulation layer is composed of multiple layers of aluminum foil and glass fiber cloth alternately stacked, and the thickness of each layer of aluminum foil is 0.1-0.3mm, and the thickness of the glass fiber cloth is 0.5-1mm.

[0018] The present invention also defines the outer surface of the insulation jacket of the heat recovery pipe. Specifically, the insulation layer is composed of multiple layers of aluminum foil and glass fiber cloth alternately stacked, wherein the thickness of each layer of aluminum foil is controlled at 0.1-0.3mm, and the thickness of the glass fiber cloth is controlled at 0.5-1mm. Thus, through this multi-layer alternating structure, the dual mechanisms of reflective insulation and barrier insulation are combined. The aluminum foil layer reflects a large amount of radiant heat through its high reflectivity, while the glass fiber cloth effectively blocks conductive heat through its low thermal conductivity. This synergistic effect makes the overall insulation performance far superior to that of traditional single-material insulation layers. More importantly, if the thickness of the aluminum foil is too thin, it will lead to insufficient mechanical strength and reduced reflective effect, while if it is too thick, it will add unnecessary weight and cost. Similarly, the limitation of the thickness of the glass fiber cloth also ensures sufficient structural support and thermal resistance effect, while avoiding the problem of reduced flexibility caused by excessive thickness.

[0019] Preferably, as a further implementable solution, the pressure control valve is an angle regulating valve, and a double valve core structure is provided in the valve body, the upper valve core is connected to the steam outlet of the pressure tower, and the lower valve core is connected to the reboiler of the atmospheric tower kettle.

[0020] In addition, the present invention also defines the specific structural design of the pressure control valve, which is an angle regulating valve. A double valve core structure is provided in the valve body, the upper valve core is connected to the steam outlet of the pressure tower, and the lower valve core is connected to the reboiler of the atmospheric pressure tower. Compared with the traditional straight-through regulating valve, the angle regulating valve can effectively reduce the turbulence and pressure drop of the fluid when it passes through because of its right-angle turn in the flow channel, thereby reducing energy loss; in the isobutyraldehyde separation system, the steam generated at the top of the pressure tower needs to be efficiently transferred to the atmospheric pressure tower reboiler, and the structure of the angle valve can ensure that the steam maintains a high kinetic energy during the flow process, avoiding steam condensation or pressure fluctuations caused by valve resistance.

[0021] Secondly, the upper valve core connects to the steam outlet of the pressure tower and regulates steam flow and pressure. The lower valve core connects to the reboiler of the atmospheric tower and controls the efficiency of heat transfer. This dual-valve core structure enables coordinated regulation of pressure and heat, avoiding the limited control accuracy often associated with a single valve core due to concentrated functions. In actual operation, the steam pressure of the pressure tower may fluctuate due to changes in feed composition or operating conditions. The dual-valve core structure enables rapid response to these fluctuations by independently adjusting the openings of the upper and lower valve cores, ensuring a stable heat load on the atmospheric tower reboiler. For example, when steam pressure rises, the upper valve core can be closed appropriately to reduce flow, while the lower valve core adjusts its opening based on the actual needs of the reboiler to maintain balanced heat transfer. This dynamic adjustment capability significantly improves system operational stability and avoids the temperature or pressure runaway caused by regulation lag associated with traditional single-valve core structures. The dual-valve core structure also enhances system safety and fault tolerance. In abnormal situations (such as a sudden increase in steam pressure or reboiler heat load), the dual valve cores work together to quickly shut off or restrict fluid flow, preventing equipment overpressure or overheating. For example, the upper valve core quickly closes upon detecting a pressure anomaly, while the lower valve core adjusts its opening based on feedback signals, ensuring that the medium in the reboiler does not overboil due to excessive heat input. This dual protection mechanism reduces the risk of system failure and extends equipment life. Furthermore, the modular design of the dual valve core structure facilitates maintenance and replacement. If one valve core becomes worn or clogged, it can be repaired independently without affecting the function of the other valve core, reducing downtime and repair costs.

[0022] Moreover, the pressure control valve of the present invention also significantly improves the energy utilization efficiency of the system. The steam at the top of the pressurized tower is rich in thermal energy, and direct discharge will cause huge waste. Through the precise adjustment of the dual-valve core pressure control valve, the thermal energy of the steam can be efficiently transferred to the reboiler of the atmospheric tower kettle, replacing the traditional electric heating or external steam heating method, thereby greatly reducing energy consumption; it is particularly noteworthy that the dual-valve core structure can dynamically adjust the heat energy input according to the actual needs of the atmospheric tower, avoiding energy redundancy or insufficiency caused by excessive steam. For example, when the separation load is low, the lower valve core can reduce the opening to match the needs of the reboiler; and at high load, the dual valve cores work together to increase the steam flow rate to ensure that the separation efficiency is not affected. This adaptive adjustment capability enables the system to maintain optimal energy efficiency under different working conditions, meeting the core requirements of green chemical industry.

[0023] Preferably, as a further implementable scheme, the top of the atmospheric tower is respectively provided with an atmospheric tower discharge port and a reflux tank inlet, the condenser is connected to the atmospheric tower through the atmospheric tower discharge port, the reflux tank is connected to the atmospheric tower through the reflux tank inlet, and the reflux tank and the condenser are both connected to the isobutyraldehyde storage tank; the bottom of the atmospheric tower is provided with an atmospheric tower discharge port, and the atmospheric tower discharge port is respectively connected to the n-butyraldehyde storage tank and the atmospheric tower kettle reboiler; the middle of the atmospheric tower is provided with a raw material liquid feed port, and the diverter is connected to the raw material liquid feed port.

[0024] Preferably, as a further implementable solution, a steam outlet and a buffer reflux tank inlet are respectively provided at the top of the pressurizing tower, the pressure controlling valve is connected to the steam outlet, and the buffer reflux tank is connected to the pressurizing tower through the buffer reflux tank inlet.

[0025] Preferably, as a further implementable solution, a circulation pipeline is further provided between the atmospheric tower kettle reboiler and the isobutyraldehyde storage tank, and the circulation pipeline is further connected to the buffer reflux tank.

[0026] Preferably, as a further feasible solution, the bottom of the pressure tower is further connected to a pressure tower kettle reboiler, and the bottom of the pressure tower is further provided with a pressure tower discharge port, and the pressure tower discharge port is connected to the n-butyraldehyde storage tank.

[0027] The core components of the separation system of the present invention include an atmospheric tower, a pressure tower, a splitter, a heat recovery system, and related pipelines and storage tanks. The specific separation process is as follows: the raw material liquid is first divided into two streams by the splitter and enters the atmospheric tower and the pressure tower respectively. The splitter design ensures even flow distribution, laying the foundation for the subsequent separation process. The coordinated operation of the atmospheric and pressurized columns is key to achieving efficient separation. The atmospheric column operates at atmospheric pressure and is primarily used to separate isobutyraldehyde, which has a lower boiling point. The pressurized column, operating under pressurized conditions, is used to separate normal butyraldehyde, which has a higher boiling point. The two columns are tightly connected via a heat recovery system, achieving cascaded energy utilization.

[0028] The heat recovery system includes a heat recovery pipeline, a reboiler for the atmospheric tower kettle, and a pressure control valve. The heat recovery pipeline adopts a double-layer casing structure, with the inner tube being a bellows and the outer tube being an insulation jacket, and inert gas is filled between the two. This design not only improves the heat transfer efficiency, but also enhances the stability and safety of the system. The inner wall of the bellows is coated with a hydrophobic-oleophilic composite coating composed of nano-silica particles and fluorinated polymers, which can effectively reduce fluid flow resistance and prevent scaling. In addition, thermally conductive ceramic particles are embedded in the troughs of the bellows, further enhancing the thermal conductivity. The outer surface of the insulation jacket is covered with a removable reflective insulation layer composed of multiple layers of aluminum foil and glass fiber cloth alternately stacked, which effectively reduces heat loss.

[0029] After the raw material liquid enters the atmospheric pressure tower, it is first distributed into the tower through the raw material liquid feed port in the middle of the tower, and then the raw material liquid is heated and vaporized by the atmospheric pressure tower reboiler arranged in the tower bottom, so that the raw material liquid rises in the tower after vaporization and undergoes mass and heat transfer with the condensate flowing down from the top of the atmospheric pressure tower, and the isobutyraldehyde with a lower boiling point gradually rises to the top of the tower. The top of the tower is provided with an atmospheric pressure tower discharge port and a reflux tank inlet. The vaporized isobutyraldehyde enters the condenser through the discharge port and flows into the isobutyraldehyde storage tank after condensation; the reflux tank is connected to the condenser, and part of the condensate refluxes into the tower as condensate to ensure separation efficiency. The design of the reflux tank avoids unstable fluctuations of the top components and improves the operational stability of the system.

[0030] The bottom of the atmospheric tower collects the higher-boiling-point n-butyraldehyde and other high-boiling-point components. A discharge port is located at the bottom of the tower, connected to the n-butyraldehyde storage tank and the atmospheric tower kettle reboiler. A portion of the bottom liquid enters the atmospheric tower reboiler, where it is reheated by the heat recovery system before returning to the tower. This circulation design ensures continuous heat utilization within the tower and reduces external energy input. The remaining bottom liquid flows as the n-butyraldehyde product into the n-butyraldehyde storage tank, completing the separation process in the atmospheric tower.

[0031] After another stream of raw liquid enters the pressurized tower, it is separated under pressurized conditions. The operating pressure of the pressurized tower is higher than that of the atmospheric pressure tower, which lowers the boiling point of n-butyraldehyde and makes it easier to vaporize. The raw liquid entering the pressurized tower is heated by the pressurized tower reboiler in the tower kettle and then vaporized and gradually rises in the tower. After contacting the condenser flowing in from the top of the tower, mass transfer and heat transfer are carried out. A steam outlet and a buffer reflux tank inlet are respectively provided on the top of the pressurized tower. The vaporized isobutyraldehyde enters the heat recovery system through the steam outlet, and the heat energy of the steam is used to heat the atmospheric pressure tower kettle reboiler. Most of the condensed isobutyraldehyde flows into the isobutyraldehyde storage tank through the circulation pipeline, and a small part flows into the buffer reflux tank. The buffer reflux tank is connected to the pressurized tower, so a small part of the isobutyraldehyde flows into the pressurized tower as a condensate for mass transfer and heat exchange, thereby realizing the separation of n-isobutyraldehyde in the pressurized tower.

[0032] The bottom of the pressurized tower is equipped with a discharge port and an externally connected reboiler. A portion of the liquid at the bottom of the tower flows through the discharge port into the n-butyraldehyde storage tank. The reboiler, using an external heat source (such as steam or electric heating), provides additional heat to maintain the desired tower bottom temperature.

[0033] The heat recovery system connects the atmospheric and pressurized towers. Its core function is to transfer the heat energy of the steam at the top of the pressurized tower to the atmospheric tower's kettle reboiler via a heat recovery pipe. Steam from the pressurized tower first enters the heat recovery pipe through a pressure-control valve. This angle-type regulating valve features a dual-spool structure within its body. The upper spool connects to the steam outlet of the pressurized tower, while the lower spool connects to the atmospheric tower's kettle reboiler. This design can precisely adjust the steam flow and pressure to ensure efficient transfer of heat energy. When the steam flows in the heat recovery pipe, its heat energy is efficiently transferred to the atmospheric tower kettle reboiler through the bellows and thermally conductive ceramic particles. The hydrophobic-oleophilic coating on the inner wall of the bellows reduces flow resistance and prevents scaling, while the thermally conductive ceramic particles further enhance the thermal conductivity. The insulating jacket and reflective insulation layer effectively reduce heat loss and ensure full utilization of heat energy. Finally, the steam condenses after releasing heat in the atmospheric tower kettle reboiler, and the condensate returns to the pressurized tower or enters the isobutyraldehyde storage tank through the circulation pipe, forming a closed-loop cycle.

[0034] Compared to traditional separation methods, the green separation system of the present invention offers significant advantages in energy conservation and environmental protection. Through the design of a heat recovery system, the system's thermal energy utilization rate is significantly improved, reducing external energy input. The use of a hydrophobic-oleophilic coating and thermally conductive ceramic particles optimizes the heat transfer process, further reducing energy consumption. Furthermore, the system's closed-loop design reduces waste heat and waste liquid emissions, in line with the development trend of green chemical industry.

[0035] In practical applications, the system can adapt to feedstocks of varying composition and flow rates, demonstrating excellent operational flexibility. For example, when the feedstock contains a high level of isobutyraldehyde, the atmospheric column load increases, but the heat recovery system dynamically adjusts heat distribution to ensure separation efficiency remains unchanged. This adaptive capability enables the system to maintain efficient and stable operation even under complex operating conditions.

[0036] The present invention also provides a reaction performed by the green n-isobutyraldehyde separation system, comprising the following steps: After the raw material liquid is divided into two streams, 40%-50% of the raw material liquid is subjected to atmospheric distillation, and 50%-60% is subjected to pressure distillation. During atmospheric distillation, the steam generated by pressure distillation is used to achieve green separation of n-butyraldehyde and isobutyraldehyde.

[0037] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides a green n-butyraldehyde and isobutyraldehyde separation system. Through efficient heat recovery and a unique pipeline design, it significantly reduces energy consumption, improves separation efficiency, and reduces environmental pollution, achieving green separation of n-butyraldehyde and isobutyraldehyde. Compared with existing technologies, the present invention offers significant improvements in energy conservation and environmental protection, separation efficiency, and system stability.

[0038] (2) The present invention provides a separation method performed by the above-mentioned green n-butyraldehyde and isobutyraldehyde separation system, which realizes the efficient and green separation of n-butyraldehyde and isobutyraldehyde, and provides a new technical path for the sustainable development of chemical production. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be construed as limiting the present invention. The same reference numerals are used throughout the accompanying drawings to denote the same components.

[0040] Figure 1 This is a structural diagram of a green n-isobutyraldehyde separation system of the present invention; Figure 2 This is a cross-sectional view of a heat recovery pipeline in a green n-isobutyraldehyde separation system of the present invention.

[0041] In the attached figure: 1. Raw liquid inlet for atmospheric tower; 2. Reflux tank; 3. Condenser; 4. Atmospheric tower; 5. Buffer reflux tank; 6. Pressure control valve; 7. Isobutyraldehyde storage tank; 8. Pressurized tower; 9. Reboiler for pressurized tower kettle; 10. Butyraldehyde storage tank; 11. Reboiler for atmospheric tower kettle; 12. Diverter; 13. Removable reflective insulation layer; 14. Inert gas; 15. Bellows; 16. Thermally conductive ceramic particles. DETAILED DESCRIPTION

[0042] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. Those who do not specify specific conditions in the embodiments are carried out according to normal conditions or the conditions recommended by the manufacturer. Those whose reagents or instruments are not specified by the manufacturer are conventional products that can be purchased commercially.

[0043] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0045] In order to more clearly illustrate the technical solutions of the present invention, specific embodiments are provided below for illustration.

[0046] Example 1 The specific separation process of green n-isobutyraldehyde of the present invention is as follows: The raw material liquid (a mixture of normal butyraldehyde and isobutyraldehyde) is first evenly divided into two streams by a splitter 12, of which 40% of the material enters the atmospheric tower 4 and 60% of the material enters the pressurized tower 8. The splitter 12 transports the first stream of material to the middle raw material liquid feed port of the atmospheric tower 4 through the atmospheric tower raw material liquid inlet 1, and at the same time transports the second stream of material to the pressurized tower 8 through the pressurized tower raw material liquid inlet; the atmospheric tower 4 operates at normal pressure, and the input raw material liquid is heated in the atmospheric tower reboiler provided in the tower bottom and then vaporized and gradually rises to contact the condenser flowing down from the tower top for mass transfer and heat transfer. At this time, the vaporized isobutyraldehyde enters the condenser 3 through the discharge port at the top of the tower, and flows into the isobutyraldehyde storage tank 7 after condensation. The reflux tank 2 is connected to the condenser 3, and part of the condensate is refluxed into the atmospheric tower 4 as condensate to ensure separation efficiency. The design of the reflux tank 2 avoids unstable fluctuations of the tower top components and improves operational stability. At the bottom of the atmospheric tower 4, n-butyraldehyde and other high-boiling-point components with a relatively high boiling point are gathered. An atmospheric tower discharge port is provided at the bottom of the tower, which is respectively connected to the n-butyraldehyde storage tank 10 and the atmospheric tower kettle reboiler 11. Part of the bottom liquid enters the atmospheric tower kettle reboiler 11, is reheated by the heat energy provided by the heat recovery system, and then returns to the tower to maintain the bottom temperature. Another part of the bottom liquid flows into the n-butyraldehyde storage tank 10 as the n-butyraldehyde product; the pressurized tower 8 is operated under pressurized conditions, and the pressure is set to an intermediate value, so that the boiling point of n-butyraldehyde is lowered, thereby making it easier to Easy to vaporize, at this time the material entering the pressurized tower is vaporized after being heated in the pressurized tower reboiler 9 and gradually rises in the tower and performs mass and heat transfer with the condensate flowing down from the top tower. The vaporized isobutyraldehyde enters the heat recovery system through the steam outlet and then flows into the atmospheric tower reboiler 11 through the heat recovery pipe for heat exchange. Subsequently, most of the condensed isobutyraldehyde flows into the isobutyraldehyde storage tank 7 through the circulation pipe, and a small part flows into the pressurized tower through the buffer reflux tank 5 connected to the pressurized tower 8 as a condenser to realize heat exchange; A pressurized tower discharge port and an external pressurized tower kettle reboiler 9 are provided at the bottom of the pressurized tower 8. The liquid at the bottom of the tower flows into the n-butyraldehyde storage tank 10 through the discharge port and is collected as a high-purity n-butyraldehyde product. The pressurized tower kettle reboiler 9 provides additional heat energy through an external heat source to ensure that the temperature at the bottom of the tower is maintained at the required level. The core of the heat recovery system of the present invention is to transfer the steam heat energy at the top of the pressurized tower 8 to the atmospheric pressure tower kettle reboiler 11 through a heat recovery pipeline. The steam at the top of the pressurized tower 8 first enters the heat recovery pipeline through a pressure control valve 6. The pressure control valve 6 is an angle regulating valve with a double valve core structure provided in the valve body. The upper valve core is connected to the steam outlet of the pressurized tower 8, and the lower valve core is connected to the atmospheric pressure tower kettle reboiler 11. This design can accurately adjust the steam flow and pressure to ensure efficient heat energy transfer. The heat recovery pipeline utilizes a double-layer casing structure, with an inner bellows 15 and an outer insulation jacket, filled with inert gas 14. The inner wall of the bellows 15 is coated with a hydrophobic-oleophilic composite coating composed of nano-silica particles (10 nm in diameter) and a fluorinated polymer (0.5 μm thick), effectively reducing fluid flow resistance and preventing scaling. Thermally conductive ceramic particles 16 are embedded in the troughs of the bellows 15, further enhancing thermal conductivity. The outer surface of the insulation jacket is covered with a removable reflective insulation layer 13, consisting of alternating layers of aluminum foil (0.1 mm thick) and fiberglass cloth (0.5 mm thick), effectively reducing heat loss. When the steam flows in the heat recovery pipe, its heat energy is efficiently transferred to the atmospheric tower kettle reboiler 11 through the bellows 15 and the heat-conducting ceramic particles 16. Finally, the steam releases heat in the atmospheric tower kettle reboiler 11 and condenses. The condensate returns to the pressurized tower 8 or enters the isobutyraldehyde storage tank 7 through the circulation pipe, forming a closed-loop circulation.

[0047] Example 2 The specific separation process of green n-isobutyraldehyde of the present invention is as follows: The raw material liquid (a mixture of normal butyraldehyde and isobutyraldehyde) is first evenly divided into two streams by a splitter 12, 50% of which enters the atmospheric tower 4 and 50% of which enters the pressurized tower 8. The splitter 12 transports the first stream of material to the middle raw material liquid feed port of the atmospheric tower 4 through the atmospheric tower raw material liquid inlet 1, and at the same time transports the second stream of material to the pressurized tower 8 through the pressurized tower raw material liquid inlet; the atmospheric tower 4 operates at normal pressure, and the input raw material liquid is heated in the atmospheric tower reboiler provided in the tower bottom and then vaporized and gradually rises to contact the condenser flowing down from the tower top for mass transfer and heat transfer. At this time, the vaporized isobutyraldehyde enters the condenser 3 through the discharge port at the top of the tower, and flows into the isobutyraldehyde storage tank 7 after condensation. The reflux tank 2 is connected to the condenser 3, and part of the condensate is refluxed into the atmospheric tower 4 as condensate to ensure separation efficiency. The design of the reflux tank 2 avoids unstable fluctuations of the tower top components and improves operational stability. At the bottom of the atmospheric tower 4, n-butyraldehyde and other high-boiling-point components with a relatively high boiling point are gathered. An atmospheric tower discharge port is provided at the bottom of the tower, which is respectively connected to the n-butyraldehyde storage tank 10 and the atmospheric tower kettle reboiler 11. Part of the bottom liquid enters the atmospheric tower kettle reboiler 11, is reheated by the heat energy provided by the heat recovery system, and then returns to the tower to maintain the bottom temperature. Another part of the bottom liquid flows into the n-butyraldehyde storage tank 10 as the n-butyraldehyde product; the pressurized tower 8 is operated under pressurized conditions, and the pressure is set to an intermediate value, so that the boiling point of n-butyraldehyde is lowered, thereby making it easier to Easy to vaporize, at this time the material entering the pressurized tower is vaporized after being heated in the pressurized tower reboiler 9 and gradually rises in the tower and performs mass and heat transfer with the condensate flowing down from the top tower. The vaporized isobutyraldehyde enters the heat recovery system through the steam outlet and then flows into the atmospheric tower reboiler 11 through the heat recovery pipe for heat exchange. Subsequently, most of the condensed isobutyraldehyde flows into the isobutyraldehyde storage tank 7 through the circulation pipe, and a small part flows into the pressurized tower through the buffer reflux tank 5 connected to the pressurized tower 8 as a condenser to realize heat exchange; A pressurized tower discharge port and an external pressurized tower kettle reboiler 9 are provided at the bottom of the pressurized tower 8. The liquid at the bottom of the tower flows into the n-butyraldehyde storage tank 10 through the discharge port and is collected as a high-purity n-butyraldehyde product. The pressurized tower kettle reboiler 9 provides additional heat energy through an external heat source to ensure that the temperature at the bottom of the tower is maintained at the required level. The core of the heat recovery system of the present invention is to transfer the steam heat energy at the top of the pressurized tower 8 to the atmospheric pressure tower kettle reboiler 11 through a heat recovery pipeline. The steam at the top of the pressurized tower 8 first enters the heat recovery pipeline through a pressure control valve 6. The pressure control valve 6 is an angle regulating valve with a double valve core structure provided in the valve body. The upper valve core is connected to the steam outlet of the pressurized tower 8, and the lower valve core is connected to the atmospheric pressure tower kettle reboiler 11. This design can accurately adjust the steam flow and pressure to ensure efficient heat energy transfer. The heat recovery pipeline utilizes a double-layered casing structure, with an inner bellows 15 and an outer insulation jacket, filled with inert gas 14. The inner wall of the bellows 15 is coated with a hydrophobic-oleophilic composite coating composed of nano-silica particles (50 nm in diameter) and a fluorinated polymer (2 μm thick), effectively reducing fluid flow resistance and preventing scaling. Thermally conductive ceramic particles 16 are embedded in the troughs of the bellows 15, further enhancing thermal conductivity. The outer surface of the insulation jacket is covered with a removable reflective insulation layer 13, consisting of alternating layers of aluminum foil (0.3 mm thick) and fiberglass cloth (1 mm thick), effectively reducing heat loss. When the steam flows in the heat recovery pipe, its heat energy is efficiently transferred to the atmospheric tower kettle reboiler 11 through the bellows 15 and the heat-conducting ceramic particles 16. Finally, the steam releases heat in the atmospheric tower kettle reboiler 11 and condenses. The condensate returns to the pressurized tower 8 or enters the isobutyraldehyde storage tank 7 through the circulation pipe, forming a closed-loop circulation.

[0048] Example 3 The specific separation process of green n-isobutyraldehyde of the present invention is as follows: The raw material liquid (a mixture of normal butyraldehyde and isobutyraldehyde) is first evenly divided into two streams by a splitter 12, of which 40% of the material enters the atmospheric tower 4 and 60% of the material enters the pressurized tower 8. The splitter 12 transports the first stream of material to the middle raw material liquid feed port of the atmospheric tower 4 through the atmospheric tower raw material liquid inlet 1, and at the same time transports the second stream of material to the pressurized tower 8 through the pressurized tower raw material liquid inlet; the atmospheric tower 4 operates at normal pressure, and the input raw material liquid is heated in the atmospheric tower reboiler provided in the tower bottom and then vaporized and gradually rises to contact the condenser flowing down from the tower top for mass transfer and heat transfer. At this time, the vaporized isobutyraldehyde enters the condenser 3 through the discharge port at the top of the tower, and flows into the isobutyraldehyde storage tank 7 after condensation. The reflux tank 2 is connected to the condenser 3, and part of the condensate is refluxed into the atmospheric tower 4 as condensate to ensure separation efficiency. The design of the reflux tank 2 avoids unstable fluctuations of the tower top components and improves operational stability. At the bottom of the atmospheric tower 4, n-butyraldehyde and other high-boiling-point components with a relatively high boiling point are gathered. An atmospheric tower discharge port is provided at the bottom of the tower, which is respectively connected to the n-butyraldehyde storage tank 10 and the atmospheric tower kettle reboiler 11. Part of the bottom liquid enters the atmospheric tower kettle reboiler 11, is reheated by the heat energy provided by the heat recovery system, and then returns to the tower to maintain the bottom temperature. Another part of the bottom liquid flows into the n-butyraldehyde storage tank 10 as the n-butyraldehyde product; the pressurized tower 8 is operated under pressurized conditions, and the pressure is set to an intermediate value, so that the boiling point of n-butyraldehyde is lowered, thereby making it easier to Easy to vaporize, at this time the material entering the pressurized tower is vaporized after being heated in the pressurized tower reboiler 9 and gradually rises in the tower and performs mass and heat transfer with the condensate flowing down from the top tower. The vaporized isobutyraldehyde enters the heat recovery system through the steam outlet and then flows into the atmospheric tower reboiler 11 through the heat recovery pipe for heat exchange. Subsequently, most of the condensed isobutyraldehyde flows into the isobutyraldehyde storage tank 7 through the circulation pipe, and a small part flows into the pressurized tower through the buffer reflux tank 5 connected to the pressurized tower 8 as a condenser to realize heat exchange; A pressurized tower discharge port and an external pressurized tower kettle reboiler 9 are provided at the bottom of the pressurized tower 8. The liquid at the bottom of the tower flows into the n-butyraldehyde storage tank 10 through the discharge port and is collected as a high-purity n-butyraldehyde product. The pressurized tower kettle reboiler 9 provides additional heat energy through an external heat source to ensure that the temperature at the bottom of the tower is maintained at the required level. The core of the heat recovery system of the present invention is to transfer the steam heat energy at the top of the pressurized tower 8 to the atmospheric pressure tower kettle reboiler 11 through a heat recovery pipeline. The steam at the top of the pressurized tower 8 first enters the heat recovery pipeline through a pressure control valve 6. The pressure control valve 6 is an angle regulating valve with a double valve core structure provided in the valve body. The upper valve core is connected to the steam outlet of the pressurized tower 8, and the lower valve core is connected to the atmospheric pressure tower kettle reboiler 11. This design can accurately adjust the steam flow and pressure to ensure efficient heat energy transfer. The heat recovery pipeline utilizes a double-layered casing structure, with an inner bellows 15 and an outer insulation jacket. Inert gas 14 is filled between the two. The inner wall of the bellows 15 is coated with a hydrophobic-oleophilic composite coating composed of nano-silica particles (particle size 30nm) and a fluorinated polymer (thickness 1.25μm), which effectively reduces fluid flow resistance and prevents scaling. Thermally conductive ceramic particles 16 are embedded in the troughs of the bellows 15, further enhancing thermal conductivity. The outer surface of the insulation jacket is covered with a removable reflective insulation layer 13, consisting of alternating layers of aluminum foil (thickness 0.2mm) and fiberglass cloth (thickness 0.75mm), effectively reducing heat loss. When the steam flows in the heat recovery pipe, its heat energy is efficiently transferred to the atmospheric tower kettle reboiler 11 through the bellows 15 and the heat-conducting ceramic particles 16. Finally, the steam releases heat in the atmospheric tower kettle reboiler 11 and condenses. The condensate returns to the pressurized tower 8 or enters the isobutyraldehyde storage tank 7 through the circulation pipe, forming a closed-loop circulation.

[0049] Experimental Example 1 Performance Test of Green Isobutyraldehyde Separation System Experimental purpose: To verify the separation efficiency, energy consumption and environmental performance of the green n-isobutyraldehyde separation system in actual operation, and to compare it with traditional distillation technology; Raw material liquid: a mixture of n-butyraldehyde and isobutyraldehyde (mass ratio 1:1); Testing instruments: gas chromatograph (GC), flow meter, temperature sensor, pressure sensor, electric energy meter; Data collection: The following parameters are recorded every 30 minutes: Purity of isolated products (GC detection); Energy consumption (the energy meter records the additional heat input to the pressurized tower kettle reboiler 9); Heat recovery efficiency (calculation of heat transfer coefficient of heat recovery pipes through temperature sensors); System stability (pressure fluctuation range);

[0050] As can be seen from the above data, the green n-isobutyraldehyde separation system and method provided by the present invention achieves efficient, energy-saving, and environmentally friendly separation of n-butyraldehyde and isobutyraldehyde through innovative structural design and process optimization. The core of the system consists of an atmospheric tower, a pressurized tower, and a heat recovery system, which significantly improves separation performance through a unique collaborative working mechanism. The three examples respectively demonstrate the technical effects under different parameter configurations, among which Example 3 achieves the best overall performance by optimizing the parameters of key components.

[0051] First, the feed liquid is evenly distributed to the atmospheric tower and the pressurized tower in a diverter, forming a dual-tower synergistic separation mode. The atmospheric tower prioritizes the separation of isobutyraldehyde with a lower boiling point at atmospheric pressure. The vaporized components at the top are condensed and purified before entering the isobutyraldehyde storage tank, while the high-boiling-point components at the bottom are circulated through a reboiler or collected as n-butyraldehyde product. The pressurized tower lowers the boiling point of n-butyraldehyde by increasing the operating pressure. The heat energy rich in the steam at the top is transferred to the atmospheric tower reboiler through an innovative heat recovery system, achieving cascaded energy utilization. This design breaks through the bottleneck of low energy utilization in traditional distillation technology and forms a highly efficient energy closed loop.

[0052] The heat recovery system is the technological essence of this invention. Its double-sleeve structure integrates multiple design features. The inner bellows are coated with a nano-scale hydrophobic-oleophilic composite coating, which prevents scaling and improves heat transfer efficiency. Thermally conductive ceramic particles embedded in the troughs further enhance heat conduction. Combined with a reflective insulation layer consisting of 0.2mm aluminum foil and 0.75mm fiberglass cloth, heat loss from the system is minimized. The pressure control valve adopts a dual-spool angle structure, which can precisely adjust steam flow and pressure, ensuring stable system operation within a very small fluctuation range of ±2.4kPa. Comparative experimental data from the three examples fully demonstrates the technological advantages. Example 3 demonstrates outstanding performance in key indicators: product purity reaches 99.87% (n-butyraldehyde) and 99.83% (isobutyraldehyde), an improvement of 1.7-1.9% over conventional technologies; unit energy consumption is only 1.18 kWh / kg, achieving an energy saving rate of 52.2%; a heat recovery rate of 87.6% enables efficient energy recycling; the system can operate continuously and stably for 168 hours, extending the maintenance cycle by 133%; and the scaling rate is as low as 0.2 times / month, reducing production interruptions caused by downtime and cleaning. These performance breakthroughs are primarily due to: optimized coating parameters that balance hydrophobicity and heat transfer efficiency; moderate insulation layer thickness that ensures thermal insulation while reducing equipment bulk; and a dual-valve core design that perfectly solves the industry's challenge of precise pressure control.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 green n-isobutyraldehyde separation system, characterized in that: It includes an atmospheric tower, a pressurized tower and a splitter, wherein the splitter is connected to the atmospheric tower and the pressurized tower through the atmospheric tower raw liquid inlet and the pressurized tower raw liquid inlet respectively; The atmospheric distillation system is connected to the pressurized distillation system via the heat recovery system; the heat recovery system comprises a heat recovery pipeline and an atmospheric tower kettle reboiler and a pressure control valve disposed on the heat recovery pipeline and connected in sequence, the atmospheric tower kettle reboiler being connected to the bottom of the atmospheric tower, and the pressure control valve being connected to the top of the pressurized tower; The heat recovery pipe adopts a double-layer casing structure, the inner pipe is a corrugated pipe, the outer pipe is an insulation jacket, and the two ends of the outer pipe are flange-connected to the atmospheric tower kettle reboiler and the pressure control valve; The space between the inner tube and the outer tube of the heat recovery pipeline is filled with inert gas.

2. The green normal-isobutyraldehyde separation system according to claim 1, characterized in that: The inner wall of the bellows is coated with a hydrophobic-oleophilic composite coating, which is composed of nano-silicon dioxide particles and fluorinated polymers. The particle size of the nano-silicon dioxide particles is 10-50 nm, and the thickness of the fluorinated polymer is 0.5-2 μm.

3. The green normal-isobutyraldehyde separation system according to claim 1, characterized in that: Heat-conducting ceramic particles are embedded in the troughs of the corrugated pipe of the heat recovery pipe.

4. The green normal-isobutyraldehyde separation system according to claim 1, characterized in that: The outer surface of the heat recovery pipe insulation jacket is covered with a detachable reflective insulation layer, which is composed of multiple layers of aluminum foil and glass fiber cloth alternately laminated, with each layer of aluminum foil having a thickness of 0.1-0.3 mm and each layer of glass fiber cloth having a thickness of 0.5-1 mm.

5. The green normal-isobutyraldehyde separation system according to claim 1, characterized in that: The pressure control valve is an angle regulating valve, and a double valve core structure is provided in the valve body. The upper valve core is connected to the steam outlet of the pressure tower, and the lower valve core is connected to the reboiler of the atmospheric tower.

6. The green normal-isobutyraldehyde separation system according to claim 1, characterized in that: The top of the atmospheric tower is respectively provided with an atmospheric tower discharge port and a reflux tank inlet, the condenser is connected through the atmospheric tower discharge port, the reflux tank is connected to the atmospheric tower through the reflux tank inlet, and the reflux tank and the condenser are both connected to the isobutyraldehyde storage tank; the bottom of the atmospheric tower is provided with an atmospheric tower discharge port, and the atmospheric tower discharge port is respectively connected to the n-butyraldehyde storage tank and the atmospheric tower kettle reboiler; the middle of the atmospheric tower is provided with a raw material liquid feed port, and the diverter is connected to the raw material liquid feed port.

7. The green normal-isobutyraldehyde separation system according to claim 1, characterized in that: A steam outlet and a buffer reflux tank inlet are respectively provided at the top of the pressurizing tower. The pressure controlling valve is connected to the steam outlet. The buffer reflux tank is connected to the pressurizing tower through the buffer reflux tank inlet.

8. The green normal-isobutyraldehyde separation system according to claim 6, characterized in that: A circulation pipeline is further provided between the atmospheric tower kettle reboiler and the isobutyraldehyde storage tank, and the circulation pipeline is also connected to the buffer reflux tank.

9. The green normal-isobutyraldehyde separation system according to claim 6, characterized in that: The bottom of the pressure tower is also externally connected to a pressure tower kettle reboiler, and the bottom of the pressure tower is also provided with a pressure tower discharge port, and the pressure tower discharge port is connected to the n-butyraldehyde storage tank.

10. A reaction carried out by the green n-isobutyraldehyde separation system according to any one of claims 1 to 9, characterized in that: The following steps are involved: After the raw material liquid is divided into two streams, 40%-50% of the raw material liquid is subjected to atmospheric distillation, and 50%-60% is subjected to pressure distillation. During atmospheric distillation, the steam generated by pressure distillation is used to achieve green separation of n-butyraldehyde and isobutyraldehyde.

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