Gas-liquid countercurrent reactor and countercurrent hydrogenation process

Abstract

The invention discloses a gas-liquid countercurrent reactor and a countercurrent hydrogenation process, the reactor comprises an upper reaction zone and a lower reaction zone, the bottom of the upper reaction zone is provided with a gas inlet, the upper part of the gas-liquid countercurrent reactor is provided with a liquid phase raw material inlet, and the upper reaction zone is provided with at least one catalyst bed layer; a pulse gas inlet is formed in the bottom of the lower reaction zone, the lower reaction zone comprises at least one group of catalytic modules, and a catalyst bag is arranged in each catalytic module and reciprocates in the lower reaction zone under the action of pulse gas. The reactor can effectively strengthen three-phase mass transfer in a catalyst bed layer, meanwhile, the lower reaction zone is filled with a movable catalyst bag, the gas-liquid mass transfer efficiency in the lower reaction zone is further strengthened on the basis of a countercurrent form, complete proceeding of high-concentration biomass hydrogenation reaction is achieved, and the yield of the high-concentration biomass hydrogenation reaction is improved. The conversion rate of the biomass and the yield of a target product are greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of biomass hydrogenation, and in particular relates to a gas-liquid countercurrent reactor and a countercurrent hydrogenation process. Background Art

[0002] Biomass is an organic compound formed through photosynthesis, including animals, plants, microorganisms and their metabolites. Biomass resources have excellent characteristics such as wide distribution and renewable nature, and are an important way to replace traditional fossil fuels.

[0003] Hydrogenation reaction technology can effectively convert biomass into high-value-added chemicals and low-oxygen or oxygen-free fuels. Taking the catalytic hydrogenation of biomass sugar as an example, the traditional reaction process usually uses a stirred tank reactor for intermittent operation. Although this method has certain advantages in the mixing uniformity of catalysts and reactants and temperature control, it has many shortcomings, such as large mechanical loss of catalysts, easy side reactions, and unstable product quality. The above defects have greatly limited the further improvement of its production scale and efficiency.

[0004] Therefore, the gas-liquid co-current continuous hydrogenation reaction device has been gradually developed and applied. Patent document US6297409B1 discloses a biomass sugar continuous catalytic hydrogenation process, which connects two or more sets of co-current fixed bed reactors (inner diameter 30cm, height 3.5m) in series, and realizes 40wt% glucose efficient continuous hydrogenation by meeting the maximum height-to-diameter ratio. The process has good glucose conversion rate and sorbitol selectivity. However, the three-phase mass transfer efficiency of the gas-liquid co-current hydrogenation process is generally low, especially the gas-liquid mixing effect in the middle and rear sections of the bed is poor, resulting in the mass transfer rate being unable to match the intrinsic reaction rate of the catalyst, which in turn affects the hydrogenation reaction efficiency.

[0005] The gas-liquid countercurrent reaction process not only improves the gas-liquid contact efficiency by causing the gas phase hydrogen and liquid phase biomass feedstock to flow in the opposite direction, but also significantly enhances the mass transfer and heat transfer effects in the reactor, effectively avoiding the inherent defects of the parallel flow process.

[0006] Patent document CN109395672A discloses a fixed bed reactor for sugar alcohol production, including a reactor body and a reactor cover, the reactor body and the reactor cover are connected by flanges, the reactor body contains a catalyst frame, the reactor cover is provided with a liquid material outlet and a gas material outlet, the lower part of the reactor is provided with a liquid material inlet and a gas material inlet, the gas inlet is provided with a pipe distributor, and the bottom of the reactor is provided with an emptying port. The device has a limit on the raw sugar concentration and is not suitable for continuous hydrogenation of high-concentration sugar solutions (≤20%).

[0007] Patent document WO2018118854A1 discloses a continuous process for preparing maltitol by hydrogenating maltose. The fixed bed device is used to achieve high conversion rate and good yield, and few by-products. However, the inventive method has certain requirements on raw material concentration (≤30%), reaction hydrogen pressure (>10MPa) and liquid hourly space velocity (≤3.0h -1 ) have strict requirements, which limits the practical industrial application of this technology.

[0008] Therefore, it is of great practical significance to develop an efficient gas-liquid countercurrent reactor and countercurrent hydrogenation process suitable for high-concentration liquid raw materials. Summary of the invention

[0009] The purpose of the present invention is to provide a gas-liquid countercurrent reactor and a countercurrent hydrogenation process. Two reaction zones are arranged in the countercurrent reactor, and a gas-liquid countercurrent contact form is adopted in the upper reaction zone to effectively strengthen the three-phase mass transfer in the catalyst bed and promote the efficient hydrogenation of biomass. At the same time, a movable catalyst package is loaded in the lower reaction zone, and the gas-liquid mass transfer efficiency in the lower reaction zone is further enhanced on the basis of the countercurrent form, so as to achieve the complete hydrogenation reaction of high-concentration biomass.

[0010] The first aspect of the present invention provides a gas-liquid countercurrent reactor, comprising an upper reaction zone and a lower reaction zone, wherein a gas inlet is provided at the bottom of the upper reaction zone, a liquid raw material inlet is provided at the top of the gas-liquid countercurrent reactor, and the upper reaction zone is provided with at least one catalyst bed; a pulse gas inlet is provided at the bottom of the lower reaction zone, the lower reaction zone comprises at least one group of catalytic modules, a catalyst package is provided in the catalytic module, and the catalyst package reciprocates in the lower reaction zone under the action of the pulse gas.

[0011] The pulse gas refers to the gas introduced into the gas-liquid countercurrent reactor from the gas inlet below the lower reaction zone in a pulsed manner, and mainly forms an intermittent high flow rate area in the lower reaction zone, generating gas impact force, causing the catalyst package in the lower reaction zone to move or vibrate periodically.

[0012] Preferably, a liquid distributor is provided between the upper reaction zone and the liquid raw material inlet, and the liquid distributor is connected to the liquid raw material inlet to achieve uniform dispersion of the liquid raw material. The liquid distributor can be various devices with liquid dispersion effect, such as trough-type liquid distributors, lotus-type liquid distributors, etc. in the art.

[0013] Preferably, a gas distributor is provided at the gas inlet at the bottom of the upper reaction zone, and the gas distributor is connected to the gas inlet to achieve preliminary dispersion of the gas phase raw materials. The gas distributor can be various devices with gas dispersion effect, such as an annular tube gas distributor in the art.

[0014] Preferably, a gas outlet is provided at the top of the reactor, a liquid material outlet is provided at the bottom of the reactor, and a gas-liquid separation component is provided between the upper reaction zone and the gas outlet at the top of the reactor to solve the problem of entrainment of mist of incompletely reacted hydrogen.

[0015] Preferably, the gas-liquid separation component is a gas-liquid separation component capable of achieving efficient gas-liquid separation at high gas velocity, including any one or more combinations of cyclone separators, baffle separators, coalescing separators, wire mesh demisters, etc.

[0016] Preferably, the gas-liquid countercurrent reactor is a biomass feedstock gas-liquid countercurrent hydrogenation reactor, the pulse gas is pulse hydrogen, and a hydrogenation catalyst is used in the catalyst bed and the catalyst package.

[0017] Under the action of the hydrogenation catalyst, the present invention realizes the preliminary hydrogenation of the biomass raw material through the countercurrent mixing of hydrogen and liquid raw materials in the upper reaction zone, and drives the catalyst package to reciprocate through the pulsed hydrogen in the lower reaction zone, thereby promoting the uniform dispersion of the liquid material in the lower reaction zone, greatly improving the gas-liquid mass transfer efficiency of the lower reaction zone, thereby fully realizing the further catalytic hydrogenation of the remaining biomass raw material and realizing deep hydrogenation.

[0018] Preferably, the upper reaction zone is used for reaction and consumes 60-80% of the initial liquid raw material, and the lower reaction zone is used for reaction and consumes 20-40% of the initial liquid raw material.

[0019] Preferably, the height of the upper reaction zone is 60-80% of the effective height of the entire reactor, and the height of the lower reaction zone is 20-40% of the effective height of the entire reactor. The effective height of the reactor is the height of the catalyst-loaded reactor.

[0020] Preferably, the height-to-diameter ratio of the upper reaction zone is 2 to 10: 1, preferably 3 to 5: 1. The characteristics of this area are that the biomass raw materials have a fast reaction rate and a large heat release. On the basis of coupling the catalyst type that is easy for material diffusion, setting a larger height-to-diameter ratio is conducive to axial diffusion of the material, preventing local hot spots, catalyst coking and reducing side reactions.

[0021] Preferably, the height-to-diameter ratio of the lower reaction zone is 1 to 3: 1, preferably 1.5 to 2.5: 1. The characteristics of this area are low reaction rate and low heat release of biomass raw materials. On the basis of coupling with a catalyst type with high reaction efficiency, setting a smaller height-to-diameter ratio is conducive to ensuring the contact efficiency between fresh raw materials and catalysts and improving the utilization rate of catalysts.

[0022] Preferably, the diameters of the upper reaction zone and the lower reaction zone are the same.

[0023] Preferably, the upper reaction zone is provided with 1 to 5 catalyst beds, preferably 1 to 2 catalyst beds.

[0024] Preferably, the lower reaction zone is provided with 1 to 50 groups of catalytic modules, preferably 5 to 20 groups of catalytic modules.

[0025] Preferably, each catalytic module is provided with 1 to 5 catalyst packages, preferably 1 to 2 catalyst packages.

[0026] Preferably, the catalyst package can be in various shapes such as rectangular parallelepiped, cube, cylinder, teardrop, sphere, etc. Preferably, it is rectangular parallelepiped, and the size of the catalyst package is preferably 10-50 mm long, 5-25 mm wide, and 50-500 mm high. The outer wrapping cloth material of the catalyst package can be any one or more of nylon, polypropylene, polyester or glass fiber.

[0027] Preferably, the catalytic module further comprises a perforated partition plate, which is in the shape of a disc and is arranged equidistantly along the axial direction of the reactor, and the catalyst is packaged on the perforated partition plate.

[0028] Preferably, the perforated partitions are fixed to the reactor wall, for example, the perforated partitions can be welded to the reactor wall, and the number of the perforated partitions is consistent with the number of catalyst claddings.

[0029] Preferably, the opening diameter of the perforated partition plate is 1 to 30 mm, preferably 2 to 10 mm.

[0030] Preferably, the opening area of ​​the perforated partition plate accounts for 5% to 30% of the total area of ​​the partition plate, preferably 10% to 20%.

[0031] Preferably, the distance between two adjacent perforated partitions is equal to the height of a single-layer catalyst package.

[0032] On the one hand, the setting of the perforated baffles can form local eddies or accelerate the flow of fluids, enhance the turbulence in the reactor, and thus promote the gas-liquid mass transfer and heat transfer efficiency in the lower reaction zone of the system; on the other hand, the perforated baffles have the function of redistribution, which can effectively avoid the phenomenon of fluid short circuit, back mixing or dead zone in the reactor. In addition, the perforated baffles can also play the role of fixing or limiting the catalyst package, so that the catalyst package moves in the limited space between adjacent baffles, preventing the catalyst particles from breaking or wearing.

[0033] Preferably, the catalytic module further comprises a metal mesh, and the metal mesh is used to wrap the catalyst package.

[0034] Preferably, the diameter of the metal mesh is smaller than the particle size of the catalyst to prevent the catalyst from running away or being lost.

[0035] Preferably, the hydrogenation catalyst loaded in the catalyst bed of the upper reaction zone is generally a conventional commercially available hydrogenation catalyst, such as Raney nickel, Raney copper, Pt / C, Pt / Al2O3 and Pd / C; the catalyst type loaded in the lower reaction zone can be a hydrogenation catalyst with the same function as that of the upper reaction zone, or different types of hydrogenation catalysts can be used according to the reaction requirements.

[0036] Preferably, the catalyst bed in the upper reaction zone is filled with a large-particle catalyst, the particle size of which is generally 1 to 6 mm, which is conducive to material diffusion, thereby preventing coking and adverse side reactions; the lower reaction zone uses a small-particle catalyst, the particle size of which is generally 0.1 to 1 mm, which can further improve material flow and reaction efficiency through the movement of the catalyst package on the basis of expanding the material contact area and improving the reaction efficiency.

[0037] In the upper reaction zone, a large-particle catalyst bed and countercurrent hydrogenation reaction are used to achieve a conversion rate of 60-80% for biomass raw materials, and the remaining materials are deeply hydrogenated in the lower reaction zone. In the lower reaction zone, a smaller aspect ratio is adopted by coupling the introduction of pulsed hydrogen and a high-efficiency catalytic module, which can effectively improve the contact efficiency between the biomass raw material and the catalyst, promote a more uniform distribution of the material on the catalyst surface, and avoid local catalyst non-wetting, thereby greatly improving the reaction rate and utilization of the catalyst, thereby ensuring the realization of a deep hydrogenation reaction.

[0038] The second aspect of the present invention provides a countercurrent hydrogenation process, which is implemented using the above-mentioned gas-liquid countercurrent reactor and comprises the following steps:

[0039] In the gas-liquid countercurrent reactor, the liquid raw material enters from the liquid raw material inlet at the top of the reactor, enters the upper reaction zone and the lower reaction zone in turn after passing through the liquid distributor, and the hydrogen enters from the gas inlet at the bottom of the upper reaction zone, enters the upper reaction zone after being dispersed by the gas distributor, and is countercurrently mixed with the liquid raw material in the upper reaction zone to undergo a preliminary hydrogenation reaction; the pulse hydrogen enters the lower reaction zone of the reactor from the bottom of the lower reaction zone, and undergoes a deep hydrogenation reaction with the mixture after the preliminary hydrogenation reaction in the lower reaction zone, and the liquid material after the deep hydrogenation reaction flows out through the liquid outlet at the bottom of the reactor, and the gas generated during the reaction is discharged from the gas outlet at the top of the reactor.

[0040] Preferably, the liquid raw material is a liquid biomass raw material, including but not limited to biomass sugar, fatty acid, glycerol, organic acid or 5-hydroxymethylfurfural.

[0041] The countercurrent hydrogenation reaction process conditions can be specifically determined according to the properties of the biomass raw material, the product quality requirements and the performance of the catalyst used. Preferably, the liquid hourly space velocity of the liquid phase biomass raw material is 0.2 to 30 h -1 , preferably 0.6 to 20 hours-1 The hydrogen pressure is 2 to 20 MPa, preferably 4 to 10 MPa, the reaction temperature is 80 to 450°C, preferably 100 to 300°C, the non-pulsed hydrogen gas-liquid volume ratio in the upper reaction zone is 5 to 500:1, preferably 20 to 100:1, the pulsed hydrogen gas-liquid volume ratio in the lower reaction zone is 250 to 1200:1, preferably 500 to 1000:1, and the ratio of pulse hydrogen duration to non-pulsed hydrogen duration is 0.5:1 to 1:15, preferably 1:1 to 1:10.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) Compared with the gas-liquid co-current reactor, the gas-liquid counter-current reactor used in the present invention effectively promotes sufficient contact between the biomass feedstock, hydrogen and the catalyst, shortens the reaction residence time, and improves the efficiency of biomass catalytic hydrogenation.

[0044] (2) As the liquid material flows downward along the axis of the reactor, the degree of hydrogenation reaction gradually deepens and the catalytic reaction rate gradually decreases. The present invention uses pulsed hydrogen to drive the catalyst package to enhance the gas-liquid mass transfer effect in the lower reaction zone, thereby ensuring sufficient contact between the reactants and the active sites of the catalyst, thereby promoting further improvement of the reaction rate and improving the conversion rate of biomass and the corresponding product yield.

[0045] (3) The upper reaction zone of the reactor of the present invention adopts a larger aspect ratio, and through a large-particle catalyst bed and a gas-liquid countercurrent form, the biomass raw material can reach a conversion rate of 60-80%, thereby realizing preliminary hydrogenation; in the lower reaction zone, by introducing pulsed hydrogen and coupling with a high-efficiency catalytic module, a smaller aspect ratio and a small-particle catalyst are used, which effectively improves the contact efficiency between the biomass raw material and the catalyst, thereby ensuring the realization of a deep hydrogenation reaction.

[0046] (4) The present invention can be widely used in the continuous hydrogenation of high-concentration biomass raw materials (such as biomass sugars such as maltose, fatty acids such as lauric acid, and organic acids such as lactic acid), and can achieve a biomass raw material conversion rate of more than 96% and a target product yield of more than 94%. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Schematic diagram of the structure of a gas-liquid countercurrent hydrogenation reactor in an embodiment of the present invention;

[0048] Among them: 1. Hydrogen inlet; 2. Liquid raw material inlet; 3. Pulse hydrogen inlet; 4. Gas outlet; 5. Liquid material outlet; 6. Gas-liquid countercurrent hydrogenation reactor; 7. Liquid distributor; 8. Gas-liquid separation component; 9. Gas distributor; 10. Upper reaction zone; 11. Lower reaction zone. DETAILED DESCRIPTION

[0049] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0050] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0051] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0052] The structural schematic diagram of the gas-liquid countercurrent hydrogenation reactor in the embodiment of the present invention is as follows Figure 1 As shown, the gas-liquid countercurrent hydrogenation reactor 6 includes an upper reaction zone 10 and a lower reaction zone 11, wherein a liquid raw material inlet 2 is provided at the upper portion of the reactor, a hydrogen inlet 1 is provided at the bottom of the upper reaction zone 10, and the upper reaction zone 10 is provided with at least one catalyst bed; a pulse hydrogen inlet 3 is provided at the bottom of the lower reaction zone 11, and the lower reaction zone 11 is composed of at least one group of catalytic modules, wherein a catalyst package is provided in the catalytic module, and the catalyst package reciprocates in the lower reaction zone 11 under the action of the pulse hydrogen.

[0053] A liquid distributor 7 is provided between the upper reaction zone 10 and the liquid raw material inlet 2, and the liquid distributor 7 is connected to the liquid raw material inlet 2 to achieve uniform dispersion of the liquid raw material. A gas distributor 9 is provided at the hydrogen inlet 1 at the bottom 10 of the upper reaction zone, and the gas distributor 9 is connected to the hydrogen inlet 1 to achieve preliminary dispersion of the gaseous raw material.

[0054] A gas outlet 4 is provided at the top of the reactor, a liquid material outlet 5 is provided at the bottom of the reactor, and a gas-liquid separation component 8 is provided between the upper reaction zone 10 and the gas outlet 4 at the top of the reactor to solve the problem of mist entrainment of unreacted hydrogen.

[0055] The process of biomass hydrogenation using the above-mentioned gas-liquid countercurrent hydrogenation reactor in the embodiment of the present invention is as follows: in the above-mentioned gas-liquid countercurrent hydrogenation reactor, the biomass liquid raw material enters from the liquid raw material inlet at the top of the reactor, and enters the upper reaction zone and the lower reaction zone in turn after passing through the liquid distributor, and hydrogen enters from the gas inlet at the bottom of the upper reaction zone, and enters the upper reaction zone after being dispersed by the gas distributor, and is countercurrently mixed with the biomass liquid raw material in the upper reaction zone to undergo a preliminary hydrogenation reaction; pulse hydrogen enters the lower reaction zone of the reactor from the bottom of the lower reaction zone, and undergoes a deep hydrogenation reaction with the mixture after the preliminary hydrogenation reaction in the lower reaction zone, and the liquid material after the deep reaction flows out through the liquid outlet at the bottom of the reactor, and the gas generated during the reaction is separated by the gas-liquid separation component and discharged from the gas outlet at the top of the reactor.

[0056] Embodiment 1:

[0057] In the gas-liquid countercurrent reactor, the effective height of the upper reaction zone is 60%, the height-to-diameter ratio is 3:1, and the catalyst is a Raney nickel catalyst with a particle size of 3-4 mm; the effective height of the lower reaction zone is 40%, the height-to-diameter ratio is 1.5:1, and the reaction zone is loaded with 10 groups of catalytic modules, each of which contains 2 catalyst packages. The catalyst package is a rectangular parallelepiped, 20 mm long, 5 mm wide, and 200 mm high. The catalyst package is made of nylon cloth. The catalyst is a Raney nickel catalyst with a particle size of 0.6-0.8 mm. The aperture of the partition is 2 mm, and the open area accounts for 20% of the total area of ​​the partition. The biomass raw material used is a 50wt% maltose aqueous solution with a liquid hourly space velocity of 1h -1 , the hydrogen pressure was 6 MPa, and the reaction temperature was 130°C. The non-pulsed hydrogen gas-liquid volume ratio in the upper reaction zone was 40:1, the pulsed hydrogen gas-liquid volume ratio in the lower reaction zone was 800:1, and the ratio of the pulsed hydrogen duration to the non-pulsed hydrogen duration was 1:2. Under the above conditions, the maltose countercurrent hydrogenation reaction was carried out, and the maltose conversion rate was 98.5% and the maltitol yield was 97.8%.

[0058] Embodiment 2:

[0059] In the gas-liquid countercurrent reactor, the effective height of the upper reaction zone is 75%, the height-to-diameter ratio is 3.5:1, and the catalyst is Pt / C catalyst with a particle size of 1-2 mm; the effective height of the lower reaction zone is 25%, the height-to-diameter ratio is 2:1, and the reaction zone is loaded with 20 groups of catalytic modules, each of which contains 1 catalyst package. The catalyst package is a rectangular parallelepiped, 30 mm long, 10 mm wide, and 400 mm high. The catalyst package is made of polypropylene cloth. The catalyst is a Raney nickel catalyst with a particle size of 0.8-1 mm. The aperture of the partition is 5 mm, and the opening area accounts for 12% of the total area of ​​the partition. The biomass raw material used is a 30wt% maltose aqueous solution with a liquid hourly space velocity of 5h -1, the hydrogen pressure was 4 MPa, and the reaction temperature was 110°C. The non-pulsed hydrogen gas-liquid volume ratio in the upper reaction zone was 80:1, the pulsed hydrogen gas-liquid volume ratio in the lower reaction zone was 500:1, and the ratio of the pulsed hydrogen duration to the non-pulsed hydrogen duration was 1:1. Under the above conditions, the maltose countercurrent hydrogenation reaction was carried out, and the maltose conversion rate was 98.9% and the maltitol yield was 98.1%.

[0060] Embodiment 3:

[0061] In the gas-liquid countercurrent reactor, the effective height of the upper reaction zone is 80%, the height-to-diameter ratio is 4:1, and the catalyst is a Raney copper catalyst with a particle size of 5-6 mm; the effective height of the lower reaction zone is 20%, the height-to-diameter ratio is 2.2:1, and the reaction zone is loaded with 15 groups of catalytic modules, each of which contains a catalyst package. The catalyst package is a rectangular parallelepiped, 40 mm long, 15 mm wide, and 500 mm high. The catalyst package is made of polyester cloth. The catalyst is a Pt / Al2O3 catalyst with a particle size of 0.2-0.4 mm. The aperture of the partition is 8 mm, and the opening area accounts for 10% of the total area of ​​the partition. The biomass raw material used is a 30wt% glycerol aqueous solution with a liquid hourly space velocity of 10h -1 , the hydrogen pressure was 5 MPa, and the reaction temperature was 220°C. The non-pulsed hydrogen gas-liquid volume ratio in the upper reaction zone was 5:1, the pulsed hydrogen gas-liquid volume ratio in the lower reaction zone was 600:1, and the ratio of the pulsed hydrogen duration to the non-pulsed hydrogen duration was 1:6. Under the above conditions, the glycerol countercurrent hydrocracking reaction was carried out, and the glycerol conversion rate was 96.6% and the propylene glycol yield was 94.4%.

[0062] Embodiment 4:

[0063] In the gas-liquid countercurrent reactor, the effective height of the upper reaction zone is 70%, the height-to-diameter ratio is 4.5:1, and the catalyst is Pt / C catalyst with a particle size of 1-2 mm; the effective height of the lower reaction zone is 35%, the height-to-diameter ratio is 2.5:1, and the reaction zone is loaded with 18 groups of catalytic modules, each of which contains 1 catalyst package. The catalyst package is a rectangular parallelepiped with a length of 40 mm, a width of 20 mm, and a height of 250 mm. The catalyst package is made of glass fiber cloth. The catalyst is a Raney copper catalyst with a particle size of 0.4-0.6 mm. The aperture of the partition is 10 mm, and the opening area accounts for 10% of the total area of ​​the partition. The biomass raw material used is a 20wt% lauric acid methanol solution, and the liquid hourly space velocity is 20h -1, the hydrogen pressure was 10 MPa, the reaction temperature was 260°C, the non-pulsed hydrogen gas-liquid volume ratio in the upper reaction zone was 300:1, the pulsed hydrogen gas-liquid volume ratio in the lower reaction zone was 1000:1, and the ratio of the pulsed hydrogen duration to the non-pulsed hydrogen duration was 1:10. Under the above conditions, the lauric acid countercurrent hydrogenation reaction was carried out, and the lauric acid conversion rate was 98.7% and the dodecanol yield was 98.0%.

[0064] Embodiment 5:

[0065] In the gas-liquid countercurrent reactor, the effective height of the upper reaction zone is 65%, the height-to-diameter ratio is 5:1, the catalyst is Pd / C catalyst, the particle size is 2-3mm, the effective height of the lower reaction zone is 35%, the height-to-diameter ratio is 1.8:1, the reaction zone is filled with 8 groups of catalytic modules, each catalytic module contains 2 catalyst packages. The catalyst package is a rectangular parallelepiped, 15mm long, 8mm wide, and 200mm high. The catalyst package is made of polypropylene cloth. The catalyst is a Raney copper catalyst with a particle size of 0.6-0.8mm. The aperture of the partition is 3mm, and the opening area accounts for 18% of the total area of ​​the partition. The biomass raw material used is a 60wt% lactic acid aqueous solution with a liquid hourly space velocity of 5h -1 , the hydrogen pressure was 2MPa, and the reaction temperature was 150°C. The non-pulsed hydrogen gas-liquid volume ratio in the upper reaction zone was 50:1, the pulsed hydrogen gas-liquid volume ratio in the lower reaction zone was 700:1, and the ratio of the pulsed hydrogen duration to the non-pulsed hydrogen duration was 1:4. Under the above conditions, the lactic acid countercurrent hydrogenation reaction was carried out, and the lactic acid conversion rate was 96.7% and the propanol yield was 95.5%.

[0066] Embodiment 6:

[0067] In the gas-liquid countercurrent reactor, the effective height of the upper reaction zone is 70%, the height-to-diameter ratio is 3.2:1, and the catalyst is Cu / Al2O3 catalyst with a particle size of 2-3mm; the effective height of the lower reaction zone is 30%, the height-to-diameter ratio is 1.5:1, and the reaction zone is loaded with 5 groups of catalytic modules, each of which contains 2 catalyst packages. The catalyst package is a rectangular parallelepiped with a length of 10mm, a width of 5mm, and a height of 50mm. The catalyst package is made of nylon cloth, and the catalyst is Pd / SiO2 catalyst with a particle size of 1-2mm. The aperture of the partition is 4mm, and the opening area accounts for 15% of the total area of ​​the partition. The biomass raw material used is a 30wt% 5-hydroxymethylfurfural methanol solution, and the liquid hourly space velocity is 20h -1, the hydrogen pressure was 5 MPa, and the reaction temperature was 240°C. The non-pulsed hydrogen gas-liquid volume ratio in the upper reaction zone was 40:1, the pulsed hydrogen gas-liquid volume ratio in the lower reaction zone was 800:1, and the ratio of the pulsed hydrogen duration to the non-pulsed hydrogen duration was 1:3. Under the above conditions, the 5-hydroxymethylfurfural countercurrent hydrogenation reaction was carried out, and the 5-hydroxymethylfurfural conversion rate was 96.3%, and the 2,5-dimethylfuran yield was 95.0%.

[0068] Comparative Example 1:

[0069] Compared with Example 1, the height-to-diameter ratio of the lower reaction zone in the gas-liquid countercurrent reactor is 3:1, and the catalyst is a Raney nickel catalyst with a particle size of 3-4 mm, which is consistent with the upper reaction zone, and no perforated baffles and pulsed hydrogen are set. The biomass raw material used is a 50wt% maltose aqueous solution with a liquid hourly space velocity of 1h -1 , hydrogen pressure was 6MPa, reaction temperature was 130℃, both upper and lower reaction zones were non-pulsed, and gas-liquid volume ratio was 40:1. Under the above conditions, maltose countercurrent hydrogenation reaction was carried out, maltose conversion rate was 85.3%, and maltitol yield was 83.7%.

[0070] It can be seen from the experimental results that the biomass hydrogenation activity of the gas-liquid countercurrent hydrogenation reaction system of the present invention is much greater than that of the countercurrent reaction system without a catalytic module and a pulse hydrogen combination.

[0071] The specific implementation methods described above provide a detailed description of the technical solutions and beneficial effects of the present invention. It should be understood that the above is only the most preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, supplements and equivalent substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A gas-liquid countercurrent reactor, characterized in that: It comprises an upper reaction zone and a lower reaction zone, wherein a gas inlet is provided at the bottom of the upper reaction zone, a liquid raw material inlet is provided at the top of the gas-liquid countercurrent reactor, and the upper reaction zone is provided with at least one catalyst bed; a pulse gas inlet is provided at the bottom of the lower reaction zone, the lower reaction zone comprises at least one group of catalytic modules, a catalyst package is provided in the catalytic module, and the catalyst package reciprocates in the lower reaction zone under the action of the pulse gas.

2. The gas-liquid countercurrent reactor according to claim 1, characterized in that: A liquid distributor is provided between the upper reaction zone and the liquid raw material inlet, and the liquid distributor is connected to the liquid raw material inlet; And / or, a gas distributor is provided at the bottom of the upper reaction zone, and the gas distributor is connected to the gas inlet; And / or, a gas outlet is provided at the top of the reactor, a liquid material outlet is provided at the bottom of the reactor, and a gas-liquid separation component is provided between the upper reaction zone and the gas outlet at the top of the reactor.

3. The gas-liquid countercurrent reactor according to claim 1 or 2, characterized in that: The gas-liquid countercurrent reactor is a biomass raw material gas-liquid countercurrent hydrogenation reactor, the pulse gas is pulse hydrogen, and a hydrogenation catalyst is used in the catalyst bed and the catalyst bag.

4. The gas-liquid countercurrent reactor according to claim 3, characterized in that: The upper reaction zone is used for reaction and consumes 60-80% of the initial liquid phase raw material, and the lower reaction zone is used for reaction and consumes 20-40% of the initial liquid phase raw material.

5. The gas-liquid countercurrent reactor according to claim 3, characterized in that: The height of the upper reaction zone is 60-80% of the effective height of the entire reactor, and the height of the lower reaction zone is 20-40% of the effective height of the entire reactor. The effective height of the reactor is the height of the catalyst-filled reactor.

6. The gas-liquid countercurrent reactor according to claim 3, characterized in that: The height-to-diameter ratio of the upper reaction zone is 2-10:1, and the height-to-diameter ratio of the lower reaction zone is 1-3:

1.

7. The gas-liquid countercurrent reactor according to claim 3, characterized in that: The upper reaction zone is provided with 1 to 5 catalyst beds; the lower reaction zone is provided with 1 to 50 groups of catalyst modules, and each catalyst module is provided with 1 to 5 catalyst packages.

8. The gas-liquid countercurrent reactor according to claim 3, characterized in that: The catalytic module comprises a perforated baffle, which is in the shape of a disc and is arranged equidistantly along the axial direction of the reactor, and the catalyst is packaged on the perforated baffle; And / or, the catalytic module comprises a metal mesh, and the metal mesh is used to wrap the catalyst package, wherein the diameter of the mesh holes of the metal mesh is smaller than the particle size of the catalyst.

9. The gas-liquid countercurrent reactor according to claim 8, characterized in that: The opening diameter of the perforated partition plate is 1-30 mm; the opening area of ​​the perforated partition plate accounts for 5-30% of the total area of ​​the partition plate.

10. The gas-liquid countercurrent reactor according to claim 3, characterized in that: The particle size of the catalyst filled in the catalyst bed is 1-6 mm; the particle size of the catalyst filled in the catalyst bag is 0.1-1 mm.

11. A countercurrent hydrogenation process, characterized in that: The method is implemented by using a gas-liquid countercurrent reactor according to any one of claims 1 to 10, comprising the following steps: In the gas-liquid countercurrent reactor, the liquid raw material enters from the liquid raw material inlet at the top of the reactor, enters the upper reaction zone and the lower reaction zone in turn after passing through the liquid distributor, and the non-pulse hydrogen enters from the gas inlet at the bottom of the upper reaction zone, enters the upper reaction zone after being dispersed by the gas distributor, and is countercurrently mixed with the liquid raw material in the upper reaction zone to undergo a preliminary hydrogenation reaction; the pulse hydrogen enters the lower reaction zone of the reactor from the bottom of the lower reaction zone, and undergoes a deep hydrogenation reaction with the mixture after the preliminary hydrogenation reaction in the lower reaction zone, and the liquid material after the deep hydrogenation reaction flows out through the liquid outlet at the bottom of the reactor, and the gas generated during the reaction is discharged from the gas outlet at the top of the reactor.

12. The countercurrent hydrogenation process according to claim 11, characterized in that: The liquid raw material is a liquid biomass raw material, including but not limited to biomass sugar, fatty acid, glycerol, organic acid or 5-hydroxymethylfurfural.

13. The countercurrent hydrogenation process according to claim 11 or 12, characterized in that: In the countercurrent hydrogenation process, the liquid phase raw material liquid hourly space velocity is 0.2 to 30h -1 , the hydrogen pressure is 2-20 MPa, the reaction temperature is 80-450°C, the non-pulsed hydrogen gas-liquid volume ratio in the upper reaction zone is 5-500:1, the pulsed hydrogen gas-liquid volume ratio in the lower reaction zone is 250-1200:1, and the ratio of pulse hydrogen duration to non-pulsed hydrogen duration is 0.5:1-1:15.

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