Biomass directional hydrogenation coupling aromatic hydrocarbon separation integrated equipment

Abstract

This invention relates to the field of biomass energy chemical technology and discloses an integrated biomass-directed hydrogenation coupled with aromatic hydrocarbon separation equipment, including a support frame, a directed hydrogenation reactor, a high-temperature gas-solid cyclone separator, and a staged condensation separation module. The reactor utilizes a spiral heat exchange jacket to achieve self-coupling preheating and temperature control of the feedstock, and a venturi micro-interface mixer at the top to enhance gas-liquid mass transfer. Internally, a dual catalytic bed and a heat and mass redistributor are installed to achieve directional conversion. The reaction products, after cyclone dust removal, enter the staged condensation separation module. A gas-liquid countercurrent washing mechanism is constructed using packing and heat exchangers in a multi-stage series condensation tower. The product components are separated by cascaded condensation through a temperature gradient, and the liquid phase product is discharged through a liquid seal at the bottom of the tower. This invention integrates reaction heat utilization, micro-interface enhancement, and anti-clogging staged separation technologies, achieving efficient preparation and high-value recovery of biomass fuel.

Description

Technical Field

[0001] This invention relates to the field of biomass energy chemical technology, specifically to an integrated equipment for biomass directional hydrogenation coupled with aromatic hydrocarbon separation. Background Technology

[0002] Biomass pyrolysis oil, as a highly promising renewable liquid fuel, can be converted into high-value-added light aromatics such as benzene, toluene, and xylene through catalytic hydrodeoxygenation technology, which is an important direction for the utilization of bioenergy.

[0003] In the reaction stage, existing hydrogenation units mostly use conventional fixed-bed reactors, where gas-liquid two-phase contact relies solely on natural flow distribution. This limited interphase mass transfer area results in low hydrogen dissolution and diffusion rates in the liquid phase, severely restricting reaction efficiency. Even more challenging is the strong exothermic effect accompanying the hydrodeoxygenation of biomass oil. Traditional reactors lack efficient internal thermal integration mechanisms, and the massive heat released during the reaction often leads to localized temperature runaway in the bed, accelerating catalyst deactivation and carbon buildup. On the other hand, a large amount of external energy is required for preheating the feedstock before it is introduced. This mismatch between heat supply and demand not only increases energy consumption but also makes it difficult to maintain long-term stability of the reaction temperature field.

[0004] In the separation stage, existing technologies typically employ single-stage condensation or simple gas-liquid separators to process high-temperature reaction products. However, due to the extremely complex composition of biomass hydrogenation products, encompassing a wide boiling point range from light gases and aromatics to heavy polycyclic aromatics, simple cooling and condensation can lead to the liquefaction of high-value light aromatics mixed with unreacted heavy components and water vapor, making it difficult to obtain high-purity products. Furthermore, heavy components in the high-temperature gas stream are prone to depositing and coking on the heat exchanger walls or valves during rapid cooling, forming difficult-to-clean blockages. This not only forces frequent shutdowns for cleaning, severely impacting production continuity and economics, but also becomes a key challenge restricting the industrial production of biomass fuel. Therefore, developing an integrated device that enhances gas-liquid mass transfer, achieves self-coupling heat utilization, and possesses anti-clogging staged separation capabilities is an urgent need in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an integrated biomass-directed hydrogenation coupled with aromatic hydrocarbon separation equipment. This equipment solves the problems of low gas-liquid mass transfer efficiency, high energy consumption and unstable temperature control in the biomass oil hydrogenation process, as well as the crude product separation that easily leads to pipeline blockage and low purity of light aromatic hydrocarbons.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an integrated biomass-directed hydrogenation coupled with aromatic hydrocarbon separation equipment, comprising: The support frame serves as the overall load-bearing foundation for the equipment; A directional hydrogenation reactor, mounted on the support frame, is used for preheating, mixing, and catalytic conversion of liquid biomass feedstock; A high-temperature gas-solid cyclone separator is connected to the bottom of the directional hydrogenation reactor and is used to separate the gas and solid products after the reaction. The staged condensation and separation module is connected to the gas phase outlet of the high-temperature gas-solid cyclone separator and is used to perform staged condensation and recovery of the purified gas phase fluid. The bottom of the directional hydrogenation reactor is provided with a gas-solid conveying pipe, and the outlet end of the gas-solid conveying pipe is connected tangentially to the inlet of the high-temperature gas-solid cyclone separator.

[0007] Preferably, the support frame includes: The skid-mounted support frame forms the main skeleton of the equipment; A reactor mounting platform is provided on the skid-mounted support frame for fixing and mounting the directional hydrogenation reactor. A separator suspension bracket is mounted on the skid-mounted support frame and is used to suspend and fix the high-temperature gas-solid cyclone separator. A saddle for mounting the condenser tower is mounted on the skid-mounted support frame and is used to support the installation of the staged condensation separation module.

[0008] Preferably, the directional hydrogenation reactor comprises: The reactor shell constitutes the main space for reaction and heat exchange; A spiral heat exchange jacket is arranged around the inside of the reactor cylinder. The bottom of the spiral heat exchange jacket is provided with a jacket raw material inlet and the top of the jacket is provided with a jacket top outlet, so that the raw material can exchange heat with the reaction zone inside the reactor cylinder in a countercurrent manner during the spiral ascent.

[0009] Preferably, the directional hydrogenation reactor further includes: A Venturi micro-interface mixer is disposed at the top of the reactor shell; The liquid inlet pipe has one end connected to the top outlet of the jacket and the other end connected to the liquid inlet of the Venturi micro-interface mixer. The Venturi micro-interface mixer is configured to shear and break down preheated raw materials from the inlet pipe with externally introduced hydrogen to form a micron-sized gas-liquid mixture that is then sprayed downwards.

[0010] Preferably, the interior of the directional hydrogenation reactor is divided into dual-catalytic reaction zones from top to bottom: The upper catalyst bed, located at the top of the reactor, contains a hydrodeoxygenation catalyst. The lower catalyst bed, located at the bottom of the reactor, contains aromatic shape-selective molecular sieve catalysts. A heat and mass redistributor is also provided between the upper catalyst bed and the lower catalyst bed for gas-liquid remixing and flow field homogenization of the fluid flowing through the upper catalyst bed.

[0011] Preferably, the staged condensation separation module includes at least one condensation tower, the condensation tower comprising: The shell of the condenser tower forms the cavity for condensation and separation; An annular gas distributor is located at the lower part of the condenser tower shell and is used to distribute the incoming gaseous fluid. An internal condenser packing assembly is positioned above the annular gas distributor; A heat exchanger, disposed inside the condenser tower shell and above the built-in condenser packing assembly, is used to remove heat so that the gas phase components condense and fall back onto the surface of the built-in condenser packing assembly to form a liquid film.

[0012] Preferably, the condensation tower further includes: A wire mesh demister is installed above the heat exchanger to remove mist droplets entrained in the rising gas. The top end cap, located at the top of the condenser tower shell, is used to collect uncondensed gas; A bottom liquid seal box is connected to the bottom of the condenser shell and is configured to form a liquid seal using the accumulated liquid phase products. A liquid product discharge pipe is installed on the bottom liquid seal box of the tower to discharge the condensed liquid product.

[0013] Preferably, the staged condensation separation module includes multiple condensation towers connected in series; The equipment also includes interstage gas connection pipes; Except for the final stage condenser, the top end cap of the previous stage condenser is connected to the annular gas distributor of the next stage condenser through the interstage gas connection pipe.

[0014] Preferably, the interstage gas connection pipes are arranged in an N-shape, configured to transport the gas from the top of the previous stage to the bottom of the next stage, so that the gas phase fluid flows from bottom to top in each stage of the condenser, forming a countercurrent contact with the condensate.

[0015] Preferably, the hydrodeoxygenation catalyst filled in the upper catalyst bed is selected from nickel-molybdenum / alumina catalyst or cobalt-molybdenum / alumina catalyst; The aromatic shape-selective molecular sieve catalyst filled in the lower catalyst bed is selected from modified ZSM-5 molecular sieve.

[0016] This invention provides an integrated device for biomass-directed hydrogenation coupled with aromatic hydrocarbon separation. It has the following beneficial effects: 1. This invention utilizes a spiral heat exchange jacket outside the reactor shell to preheat the cold raw material in a countercurrent manner using the excess heat released from the reaction. This achieves self-coupling heating of the raw material, reducing energy consumption, and effectively removes heat from the core reaction zone to prevent overheating. Combined with the Venturi micro-interface mixer at the top, the gas and liquid phases are sheared and broken into micron-sized emulsions, greatly increasing the interphase contact area, thereby achieving a high-efficiency hydrogenation reaction rate at a lower pressure.

[0017] 2. This invention sets up a hydrodeoxygenation bed and an aromatic shape-selective molecular sieve bed from top to bottom in the reactor, and uses an intermediate heat and mass redistributor to eliminate local hot spots generated by the upper reaction and to rectify the flow field, thus realizing an orderly staged conversion of deoxygenation followed by aromatization. The above method not only avoids catalyst deactivation caused by excessive temperature rise in a single bed, but also improves the selectivity and yield of high-value-added light aromatics such as benzene, toluene, and xylene through shape-selective catalysis.

[0018] 3. This invention utilizes the multi-stage series structure of the staged condensation separation module and the built-in condensation packing assembly to construct a gas-liquid countercurrent contact washing-distillation mechanism. By taking advantage of the dew point differences of different components, heavy oil, middle distillate and light aromatics are enriched in condensation towers at different temperature levels. The above-mentioned in-situ separation method not only eliminates the need for complex distillation tower equipment, but also effectively prevents the deposition of heavy components in the low temperature zone and pipeline blockage through the countercurrent washing effect of the liquid film, ensuring the long-term stable operation of the device. Attached Figure Description

[0019] Figure 1 This is a perspective view of the present invention; Figure 2 This is a cross-sectional view of the directional hydrogenation reactor of the present invention; Figure 3 This is a schematic diagram of the internal structure of the directional hydrogenation reactor of the present invention; Figure 4 This is a side view of the present invention; Figure 5 This is a schematic diagram of the staged condensation separation module of the present invention; Figure 6 This is a schematic diagram of the internal structure of the staged condensation separation module of the present invention; Figure 7 This is a schematic diagram of the support frame of the present invention.

[0020] The components include: 1. Support frame; 101. Skid-mounted support frame; 102. Reactor mounting platform; 103. Condenser tower mounting saddle; 104. Separator suspension bracket; 2. Directional hydrogenation reactor; 201. Reactor shell; 202. Spiral heat exchange jacket; 203. Jacket feed inlet; 204. Jacket top outlet; 205. Venturi micro-interface mixer; 206. Liquid inlet pipe; 207. Upper catalyst bed; 208. Heat and mass redistributor; 209. Lower catalyst bed; 210. Gas-solid conveying pipe; 3. High-temperature gas-solid cyclone separator; 4. Staged condensation separation module; 401. Condenser tower shell; 402. Heat exchanger; 403. Built-in condensation packing assembly; 404. Wire mesh demister; 405. Tower top end cap; 406. Annular gas distributor; 407. Tower bottom liquid seal box; 408. Liquid phase product discharge pipe; 5. Interstage gas connection pipe. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see the appendix Figure 1 - Appendix Figure 7 This invention provides an integrated biomass directional hydrogenation coupled with aromatic hydrocarbon separation equipment. The main body of the equipment is integrated by skid mounting through a support frame 1. The directional hydrogenation reactor 2, the staged condensation separation module 4 and the high-temperature gas-solid cyclone separator 3 are respectively fixedly mounted on the reactor mounting platform 102, the condensation tower mounting saddle 103 and the separator suspension bracket 104 on the skid support frame 101. The main body of the directional hydrogenation reactor 2 is a reactor cylinder 201, which is provided with a spiral heat exchange jacket 202 on its outer wall or inside. The bottom of the jacket is provided with a jacket raw material inlet 203, and the top of the jacket is provided with a jacket top outlet 204. The outlet is connected to the Venturi micro-interface mixer 205 at the top of the reactor through an external liquid inlet pipe 206. The reactor is filled from top to bottom with an upper catalyst bed 207 (preferably filled with sulfide nickel-molybdenum or cobalt-molybdenum hydrogenation deoxygenation catalyst in this embodiment) and a lower catalyst bed 209 (preferably filled with modified ZSM-5 molecular sieve catalyst in this embodiment), and a heat and mass redistributor 208 is provided between the two beds. The gas-solid conveying pipe 210 at the bottom of the reactor is tangentially connected to the high-temperature gas-solid cyclone separator 3, while the gas phase outlet of the separator is connected to the staged condensation separation module 4. This module consists of multiple condensation towers connected in series. Each stage of the condensation tower is connected to the interstage gas connection pipe 5 arranged in an N-shape. That is, the top end cap 405 of the upper stage tower is connected to the annular gas distributor 406 at the bottom of the lower stage tower. From bottom to top, each stage of the tower is provided with a bottom liquid seal box 407, an annular gas distributor 406, an internal condensation packing assembly 403, a heat exchanger 402, and a wire mesh demister 404.

[0023] During operation, liquid biomass feedstock is first pumped into the jacket feedstock inlet 203 at the bottom of the directional hydrogenation reactor 2. Under pressure, it spirals upward along the spiral heat exchange jacket 202, during which it undergoes countercurrent heat exchange with the reactor shell 201, maintaining a high-temperature reaction zone of 400℃-450℃. The feedstock is preheated to approximately 250℃ while excess heat from the reactor wall is removed to maintain a stable bed temperature. The preheated feedstock flows out from the top outlet 204 of the jacket and is introduced into the top Venturi micro-interface mixer 205 via the liquid inlet pipe 206. Here, it undergoes intense shearing and breaking down with high-pressure hydrogen to form micron-sized particles. The emulsified gas-liquid mixture is sprayed downwards. The mixture first enters the upper catalyst bed 207 to undergo hydrogenation, deoxygenation, decarbonylation, and decarboxylation reactions, releasing heat. The reaction fluid is then remixed and homogenized in the temperature field by the heat and mass redistributor 208 before entering the lower catalyst bed 209, where cyclization, dehydrogenation, and aromatization reactions occur to directionally generate light aromatics. The high-temperature gas-solid mixture generated by the reaction is tangentially introduced into the high-temperature gas-solid cyclone separator 3 through the bottom gas-solid conveying pipe 210. Under centrifugal force, solid impurities are separated, and the purified gas phase fluid enters the staged condensation separation module 4 for cascaded recovery.

[0024] In the staged condensation process, the gaseous fluid flows through each stage of the condenser in the order of high temperature, medium temperature, and low temperature. Differential condensation is achieved by controlling the medium temperature in the heat exchanger 402: the gaseous fluid is evenly distributed by the annular gas distributor 406 at the bottom of the condenser shell 401 and flows upward, passing through the built-in condenser packing assembly 403 and the heat exchanger 402 in sequence. Under the action of heat removal by the heat exchanger 402, the heavy components in the gas phase (such as heavy oil in the first stage of condensation or xylene in the second stage of condensation) condense into droplets and fall back to the surface of the packing to form a liquid film. This liquid film forms a countercurrent gas-liquid contact with the rising gas flow and is used for washing and distillation, effectively preventing blockage by heavy components. The subsequent pipeline is plugged and the purity of the light components is improved; the uncondensed gas continues to rise and after the mist droplets are removed by the wire mesh demister 404, it gathers at the top end cap 405 of the tower and is transported to the annular gas distributor 406 of the next stage condenser tower through the interstage gas connection pipe 5 for deeper separation at a lower temperature (such as the third stage condensation of benzene and toluene); while the condensed liquid products fall into the bottom liquid seal box 407 of the tower. The accumulated liquid submerges the front end of the outlet. When the liquid height reaches the preset liquid level, a liquid column static pressure liquid seal is formed to effectively prevent gas phase short circuit. The overflow is discharged in stages through the liquid product discharge pipe 408, thereby realizing the efficient preparation of biomass fuel and the graded collection of components.

[0025] Working principle: When this device is in operation, the liquid biomass feedstock is first pumped into the jacket feedstock inlet 203 at the bottom of the directional hydrogenation reactor 2. Under pressure, it spirals upward along the spiral heat exchange jacket 202. During this process, it exchanges heat with the high-temperature reaction zone inside the reactor shell 201 in a countercurrent manner. On the one hand, it absorbs the heat of reaction to achieve self-coupling preheating of the feedstock. On the other hand, it removes the excess heat of reaction in the core area of ​​the reactor to maintain the stability of the bed temperature. The preheated feedstock flows out from the top outlet 204 of the jacket and is introduced into the top Venturi micro-interface mixer 205 through the liquid inlet pipe 206. Here, it is sheared and broken with high-pressure hydrogen to form a micron-sized emulsion gas-liquid mixture and is sprayed downward. The mixed flow first enters the upper catalyst bed 207 filled with nickel-molybdenum or cobalt-molybdenum hydrodeoxygenation catalyst, where hydrodeoxygenation, decarbonylation and decarboxylation reactions occur and heat is released. After the reaction fluid is remixed and the temperature field is homogenized by the heat and mass redistributor 208, it enters the lower catalyst bed 209 filled with ZSM-5 shape-selective molecular sieve, where cyclization, dehydrogenation and aromatization reactions occur to directionally generate light aromatics. The high-temperature gas-solid mixture generated by the reaction is tangentially introduced into the high-temperature gas-solid cyclone separator 3 through the bottom gas-solid conveying pipe 210, where solid impurities are separated under the action of centrifugal force. The purified gaseous fluid enters the staged condensation and separation module 4 for cascaded recovery. The gaseous fluid is evenly distributed by the annular gas distributor 406 at the bottom of the condensation tower shell 401 and flows upward. It passes through the built-in condensation packing assembly 403 and heat exchanger 402 in sequence. Under the action of heat removal by the heat exchanger 402, the heavy components in the gaseous phase condense into droplets and fall back to the surface of the packing to form a liquid film. It forms a gas-liquid countercurrent contact and washing distillation with the rising gas flow. The uncondensed gas continues to rise and passes through the wire mesh demister 404 to remove the mist droplets before converging at the top head 405 of the tower. It is then transported to the annular gas distributor 406 of the next stage condensation tower through the interstage gas connection pipe 5 for deeper separation at a lower temperature. The condensed liquid products fall into the bottom liquid seal box 407. When the liquid level reaches the preset level, a liquid seal is formed to prevent gas phase short circuit. The overflow is discharged in stages through the liquid product discharge pipe 408, thereby realizing the efficient preparation of biomass fuel and the graded collection of components.

Claims

1. An integrated biomass-directed hydrogenation coupled with aromatic hydrocarbon separation equipment, characterized in that, include: The support frame (1) serves as the overall load-bearing foundation for the equipment; A directional hydrogenation reactor (2) is mounted on the support frame (1) and is used for preheating, mixing and catalytic conversion of liquid biomass feedstock; A high-temperature gas-solid cyclone separator (3) is connected to the bottom of the directional hydrogenation reactor (2) and is used to separate the gas and solid products after the reaction. The staged condensation separation module (4) is connected to the gas phase outlet of the high-temperature gas-solid cyclone separator (3) and is used for staged condensation and recovery of the purified gas phase fluid. The bottom of the directional hydrogenation reactor (2) is provided with a gas-solid conveying pipe (210), and the outlet end of the gas-solid conveying pipe (210) is connected to the inlet of the high-temperature gas-solid cyclone separator (3) in a tangential direction.

2. The integrated biomass directional hydrogenation coupled aromatic hydrocarbon separation equipment according to claim 1, characterized in that, The support frame (1) includes: The skid-mounted support frame (101) forms the main skeleton of the equipment; The reactor mounting platform (102) is set on the skid-mounted support frame (101) and is used to fix the directional hydrogenation reactor (2). The separator suspension bracket (104) is mounted on the skid-mounted support frame (101) and is used to suspend and fix the high-temperature gas-solid cyclone separator (3). A saddle (103) for installing a condenser tower is mounted on the skid-mounted support frame (101) and is used to support the installation of the staged condensation separation module (4).

3. The integrated biomass directional hydrogenation coupled aromatic hydrocarbon separation equipment according to claim 1, characterized in that, The directed hydrogenation reactor (2) includes: The reactor shell (201) constitutes the main space for reaction and heat exchange; A spiral heat exchange jacket (202) is arranged around the inside of the reactor cylinder (201). The bottom of the spiral heat exchange jacket (202) is provided with a jacket raw material inlet (203) and the top of the jacket is provided with a jacket top outlet (204), so that the raw material can exchange heat with the reaction zone inside the reactor cylinder (201) in a countercurrent manner during the spiral ascent.

4. The integrated biomass directional hydrogenation coupled aromatic hydrocarbon separation equipment according to claim 3, characterized in that, The directed hydrogenation reactor (2) also includes: A Venturi micro-interface mixer (205) is disposed at the top of the reactor shell (201); The liquid inlet pipe (206) is connected at one end to the top outlet (204) of the jacket and at the other end to the liquid inlet of the Venturi micro-interface mixer (205); The Venturi micro-interface mixer (205) is configured to shear and break up preheated raw materials from the inlet pipe (206) with externally introduced hydrogen to form a micron-sized gas-liquid mixture that is then sprayed downwards.

5. The integrated biomass directional hydrogenation coupled aromatic hydrocarbon separation equipment according to claim 1, characterized in that, The interior of the directional hydrogenation reactor (2) is divided into dual-catalytic reaction zones from top to bottom: The upper catalyst bed (207) is located at the top of the reactor and contains a hydrodeoxygenation catalyst. The lower catalyst bed (209) is located at the bottom of the reactor and is equipped with an aromatic shape-selective molecular sieve catalyst. A heat and mass redistributor (208) is also provided between the upper catalyst bed (207) and the lower catalyst bed (209) for gas-liquid remixing and flow field homogenization of the fluid flowing through the upper catalyst bed (207).

6. The integrated biomass directional hydrogenation coupled aromatic hydrocarbon separation equipment according to claim 1, characterized in that, The staged condensation separation module (4) includes at least one stage of condensation tower, the condensation tower comprising: The condenser tower shell (401) forms the cavity for condensation separation; An annular gas distributor (406) is disposed at the lower part of the condenser shell (401) for distributing the incoming gaseous fluid. An internal condenser packing assembly (403) is disposed above the annular gas distributor (406); A heat exchanger (402) is disposed inside the condenser shell (401) and above the built-in condenser packing assembly (403) for removing heat to condense the gas phase components and allow them to fall back onto the surface of the built-in condenser packing assembly (403) to form a liquid film.

7. The integrated biomass directional hydrogenation coupled aromatic hydrocarbon separation equipment according to claim 6, characterized in that, The condenser also includes: A wire mesh demister (404) is disposed above the heat exchanger (402) and is used to remove mist droplets entrained in the rising gas. The top end cap (405) is located at the top of the condenser shell (401) and is used to collect uncondensed gas; A bottom liquid seal box (407) is connected to the bottom of the condenser shell (401) and is configured to form a liquid seal using the accumulated liquid phase products; A liquid product discharge pipe (408) is installed on the bottom liquid seal box (407) of the tower and is used to discharge the condensed liquid product.

8. The integrated biomass directional hydrogenation coupled aromatic hydrocarbon separation equipment according to claim 7, characterized in that, The staged condensation separation module (4) includes multiple condensation towers connected in series; The equipment also includes an interstage gas connection pipe (5); Except for the final stage condenser, the top end cap (405) of the previous stage condenser is connected to the annular gas distributor (406) of the next stage condenser through the interstage gas connection pipe (5).

9. The integrated biomass directional hydrogenation coupled aromatic hydrocarbon separation equipment according to claim 8, characterized in that, The interstage gas connection pipe (5) is arranged in an N-shape and is configured to transport the gas from the top of the previous stage to the bottom of the next stage, so that the gas phase fluid flows from bottom to top in each stage of the condenser and forms a countercurrent contact with the condensate.

10. The integrated biomass directional hydrogenation coupled aromatic hydrocarbon separation equipment according to claim 5, characterized in that, The hydrogenation deoxygenation catalyst filled in the upper catalyst bed (207) is selected from nickel-molybdenum / alumina catalyst or cobalt-molybdenum / alumina catalyst. The aromatic shape-selective molecular sieve catalyst filled in the lower catalyst bed (209) is selected from modified ZSM-5 molecular sieve.

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