Novel slurry bed reactor and reaction method

Abstract

The invention discloses a novel slurry bed reactor and a reaction method. The novel slurry bed reactor comprises a reactor shell, a spiral filler, a fluid distribution device and a reactor base. The core of the invention lies in that the spiral filler can promote liquid to be condensed to form a liquid bridge, and the liquid bridge flows downwards along a spiral track, so that a unique semi-constrained liquid flowing mode is constructed. In the mode, gas-phase molecules firstly realize efficient mass transfer at the spiral liquid film and then diffuse to the surface of the catalyst for reaction. The design effectively solves the problems of low mass transfer efficiency, high pressure drop, non-uniform fluid distribution, serious flow back mixing and the like of the traditional slurry bed, and obviously improves the reaction performance. The reactor integrates a distribution and temperature control system, and is suitable for various catalytic reactions and gas-liquid mass transfer strengthening processes.

Description

Technical Field

[0001] This invention relates to the field of chemical reaction equipment technology, specifically to a slurry bed reactor using spiral liquid bridge falling film structured packing, suitable for gas-liquid-solid three-phase catalytic reaction processes. Background Technology

[0002] Heterogeneous catalytic reactions are a core process in modern chemical industry, and the performance of their reactors directly affects product yield, energy consumption, and process feasibility. Slurry bed reactors, with their advantages of homogeneous gas-liquid-solid three-phase mixing, high heat and mass transfer efficiency, and high operational flexibility, have irreplaceable industrial value in energy and chemical engineering, fine synthesis, and bioconversion. Taking the hydrogenation of anthraquinone to hydrogen peroxide as an example, the mild flow conditions of a slurry bed can effectively suppress deep hydrogenation side reactions and ensure product selectivity; its continuous operation characteristics and online catalyst replacement function further significantly improve process economy.

[0003] However, the performance of slurry bed reactors is highly dependent on the internal three-phase flow state, and non-ideal flow behavior has become a key bottleneck restricting their efficiency. Among them, uneven gas holdup distribution and reduced backmixing are typical challenges: uneven gas holdup distribution will form flow dead zones, thus significantly weakening mass transfer efficiency, while backmixing will reduce the selectivity and conversion rate of reactants.

[0004] To address the aforementioned shortcomings, existing technologies primarily enhance mixing and heat removal by adding internal components such as vertical heat exchange tubes, porous distribution plates, flow guide tubes, or mechanical stirrers within the reactor. For example:

[0005] CN112316857A proposes a "spiral flow slurry bed reactor," which features a gas distributor at the bottom of the reactor composed of multiple spiral tubes, annular tubes, and downwardly angled gas distribution pipes, creating a clockwise / counterclockwise rotating flow of the incoming gas. Simultaneously, a combination of "guide tube-shaped + spiral plate-shaped" heat exchange tubes is arranged within the gas-slurry mixing zone. Utilizing the flow-guiding and heat-removing coupling effect of the spiral heat exchange tubes, backmixing and dead zones are suppressed, improving Fischer-Tropsch synthesis efficiency. This scheme improves temperature uniformity by synergistically generating an overall rotating flow field through "spiral gas distribution + spiral heat exchange." However, the structure is complex and difficult to manufacture, and the spiral tube assembly primarily addresses macroscopic swirling flow, offering limited impact on bubble size and secondary breakup within the packing layer.

[0006] CN120586773A discloses "a slurry bed reactor with a novel spiral tube," in which two spiral heat exchange tubes are arranged coaxially inside the tower. Cooling water enters from the lower end and exits from the upper end, serving as both a heat removal element and inducing forced vortices in the slurry through the spiral surface, reducing the flow velocity in the central region and suppressing the chimney effect. The outer wall of the tube can be sprayed with porous material or processed with spiral corrugations to anchor the catalyst and increase the gas-liquid-solid contact area. However, relying solely on two spiral tubes makes it difficult to form a uniform and controllable liquid bridge network throughout the bed, and there are still shortcomings in terms of bubble breakage and liquid phase distribution uniformity under high apparent gas velocities.

[0007] To address these issues, researchers have introduced structured packing technology into slurry bed reactor design. By precisely controlling the flow field through geometric constraints, they aim to suppress backmixing and optimize the interphase contact interface. However, despite the significant advantages of structured internals, their engineering application still faces two key challenges: First, existing structures struggle to simultaneously achieve flow field control and mass transfer enhancement. Their complex flow channels, while suppressing backmixing, often lead to a 30%-50% increase in gas pressure drop, which is particularly detrimental to high-pressure reaction systems. Second, the scale-up design of traditional structured packings lacks reliable theoretical guidance, often relying on trial and error, resulting in difficult and costly reactor scale-up processes. These challenges limit the widespread application potential of structured packings in solving slurry bed flow and mass transfer bottlenecks.

[0008] Therefore, developing novel slurry bed reactor devices that can effectively address the inherent defects of slurry beds and overcome the challenges of applying traditional structured packings is an important research direction for gas-liquid-solid three-phase reactions. Summary of the Invention

[0009] To address the shortcomings and deficiencies of existing technologies, the present invention aims to provide a novel slurry bed reactor that utilizes the excellent liquid self-distribution properties of its internal spiral liquid bridge falling film structure to achieve uniform liquid distribution, significantly enhance mass transfer efficiency, and maintain a low pressure drop. This solves bottleneck problems such as severe backmixing in the slurry bed, uneven gas-liquid distribution, and difficulties in reactor scale-up.

[0010] This invention is achieved through the following technical solution:

[0011] A first aspect of the present invention is to provide a novel slurry bed reactor, comprising:

[0012] Reactor shell: Vertically placed, it is a cylindrical sleeve structure with an outer jacket, and the upper and lower parts of the jacket are respectively provided with a heat transfer oil outlet and a heat transfer oil inlet;

[0013] Spiral packing: Vertically installed inside the internal cavity of the reactor shell, with its upper end fixed to the inner tube of the fluid distribution system;

[0014] Fluid distribution system: Located above the reactor shell, it is a semi-closed hollow tube structure with an open bottom. It has a gas phase inlet at the top and a liquid phase inlet on the side, and a gas phase distribution port on the inner tube wall. The fluid distribution system is sealed to the upper end of the reactor shell through a flange connection.

[0015] Reactor base: Located below the reactor shell, it is a semi-closed tubular structure with an open top. It has a gas phase outlet on the upper side wall, a liquid phase outlet on the lower side wall, and a temperature sensor interface at the bottom. The reactor base is sealed to the lower end of the reactor shell through a flange connector.

[0016] The core innovation of this reactor lies in its helical packing structure. Supported by equidistant helical lines, the packing promotes liquid condensation, forming liquid bridges that flow downwards along the helical trajectory, thus creating a unique semi-confined liquid flow mode. In this mode, gas molecules first achieve efficient gas-liquid mass transfer at the inner and outer liquid films of the helical structure, and then diffuse to the surface of suspended catalyst particles for catalytic reaction. Through the unique design of the aforementioned helical structure, this invention effectively solves the problems of low mass transfer efficiency, high pressure drop, uneven fluid distribution, and severe backmixing in traditional slurry bed reactors. It significantly improves mass transfer efficiency and reaction selectivity, reduces system pressure drop, and achieves uniform gas-liquid fluid distribution and significant suppression of backmixing. This reactor integrates a fluid distribution device and a temperature control system, making it suitable for various catalytic reactions and enhanced gas-liquid mass transfer processes, exhibiting excellent overall performance.

[0017] In the above technical solution, the spiral packing is formed by continuously winding a single circular cross-section metal wire along a spiral trajectory with equal diameter and equal pitch, thus forming a vertical spiral structure with uniform spiral gap.

[0018] In the above technical solution, the diameter of the spiral packing wire is 1.5mm to 2.5mm, the outer diameter of the spiral is 10mm to 14mm, the pitch is 1.5mm to 2.5mm, and the height is 350mm to 450mm.

[0019] In the above technical solution, the ratio of the height of the reactor shell to its outer cross-sectional diameter is 35:9 to 45:9; the ratio of the diameter of the internal cavity cross-section of the reactor shell to its outer cross-sectional diameter is 3:9 to 5:9; and the opening diameter of the heat transfer oil inlet and outlet is 5mm to 7mm.

[0020] In the above technical solution, the ratio of the outer diameter of the inner tube to the inner diameter of the outer tube of the fluid distribution system is 1:2.5 to 1:3.5; the opening diameter of the gas phase inlet is 5mm to 7mm; the opening diameter of the liquid phase inlet is 2mm to 4mm; and the opening diameter of the gas phase distribution port is 3mm to 5mm.

[0021] In the above technical solution, the opening diameter of the gas phase outlet is 5mm to 7mm; the opening diameter of the liquid phase outlet is 5mm to 7mm; and the opening diameter of the sensor interface is 2mm to 4mm.

[0022] A second aspect of the present invention provides a method for performing a gas-liquid-solid three-phase catalytic reaction using the novel slurry bed reactor, comprising the following steps: gaseous reactants enter from the gas phase inlet of the fluid distribution system, are distributed through the gas phase distribution port, and flow into the interior of the reactor shell; a slurry liquid phase containing catalyst particles enters from the liquid phase inlet of the fluid distribution system and is guided and distributed to the surface of the spiral packing; the slurry liquid phase flows downward along the spiral trajectory of the spiral packing under gravity, forming a liquid bridge; the downward flowing slurry liquid phase and the upward or co-flowing gaseous reactants undergo gas-liquid mass transfer in the gaps and on the surface of the spiral packing; the mass-transferred gaseous reactants diffuse to the surface of the catalyst particles suspended in the slurry liquid phase for catalytic reaction; the tail gas after the reaction leaves the reactor from the gas phase outlet of the reactor base; the slurry liquid phase product after the reaction leaves the reactor from the liquid phase outlet of the reactor base.

[0023] Compared with the prior art, the present invention has the following main advantages:

[0024] (1) The spiral packing used in this invention significantly reduces the flow resistance of the gas phase when passing through the packing, thus achieving a lower system pressure drop.

[0025] (2) The spiral packing used in this invention has strong fluid self-distribution performance in the equidistant spiral gaps, and the packing adopts an independent unitized structure design, which effectively ensures the uniform distribution of gas and liquid phases on the reactor, overcoming the problems of severe flow deviation and back mixing that are prone to occur in traditional slurry bed reactors.

[0026] (3) The spiral packing used in this invention makes both its external surface and internal gaps highly efficient gas-liquid contact sites. Its effective gas-liquid contact area is significantly increased, which greatly promotes the mass and heat transfer process.

[0027] (4) In the process of the liquid phase flowing downward along the spiral trajectory in the device of the present invention, it is subjected to the centrifugal force induced by the spiral, which effectively prolongs its residence time in the packing. Furthermore, the residence time of the reactants in the reactor can be precisely controlled by adjusting the height of the packing. For reaction processes with many side reactions, the selectivity of the target product can be significantly improved. Attached Figure Description

[0028] Figure 1 This is a front view of the reactor of the present invention;

[0029] Figure 2This is a cross-sectional view of the fluid distribution system of the present invention;

[0030] Figure 3 This is a diagram showing the specifications of the spiral packing of the present invention; the parameters are: spiral length (H), diameter (D), pitch (W), wire diameter (d), and spring tilt angle (θ).

[0031] Wherein: 1 is the reactor shell; 2 is the spiral packing; 3 is the fluid distribution system; 4 is the reactor base; 5 is the gas phase inlet; 6 is the liquid phase inlet; 7 is the heat transfer oil outlet; 8 is the heat transfer oil inlet; 9 is the gas phase outlet; 10 is the liquid phase outlet; 11 is the temperature sensor interface. Detailed Implementation

[0032] The following is in conjunction with the appendix Figures 1 to 3 The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the following embodiments are illustrative and not limiting, and should not be used to limit the scope of protection of the present invention.

[0033] The reactor shell mentioned in the following embodiments is made of quartz to facilitate observation of the phenomena during the experiment. The spiral packing, fluid distribution system and reactor base are made of 304 stainless steel to prevent oxidation during use and thus affect normal operation.

[0034] A novel slurry bed reactor includes a reactor shell 1, a spiral packing 2, a fluid distribution system 3, and a reactor base 4. The reactor shell 1 is vertically placed and is a cylindrical sleeve structure with an outer jacket. The upper and lower parts of the jacket are respectively provided with a heat transfer oil outlet 7 and a heat transfer oil inlet 8. The spiral packing 2 is vertically arranged in the internal cavity of the reactor shell 1, and its upper end is fixed to the inner tube of the fluid distribution system 3. The fluid distribution system 3 is located above the reactor shell 1 and is a semi-closed hollow sleeve structure with an open lower end. It is provided with a gas phase inlet 5 at the upper part and a liquid phase inlet 6 on the side. The inner tube wall is provided with a gas phase distribution port. The fluid distribution system 3 is sealed to the upper end of the reactor shell 1 through a flange connection. The reactor base 4 is located below the reactor shell 1 and is a semi-closed tubular structure with an open upper end. It is provided with a gas phase outlet 9 at the upper part of its side wall, a liquid phase outlet 10 at the lower part of its side wall, and a temperature sensor interface 11 at the bottom. The reactor base 4 is sealed to the lower end of the reactor shell 1 through a flange connection.

[0035] The anthraquinone working solution mentioned in the following examples was prepared by dissolving 2-ethylanthraquinone (EAQ) in a mixed solvent of trioctyl phosphate (TOP) and thiol, with a volume ratio of thiol to TOP of 3:1. A 5% Pd / Al₂O₃ catalyst with an average particle size of 77 μm was used as the catalyst. The catalyst loading in the reaction was 0.8%.

[0036] The product analysis method in the following examples was as follows: 5 ml of the hydrogenated product was continuously oxidized with air for 30 minutes, followed by extraction three times with 10 ml of deionized water. The H2O2 content was analyzed by titration of the aqueous phase with KMnO4 standard solution. Furthermore, the concentrations of EAQ and H4EAQ in the oil phase were analyzed by high-performance liquid chromatography (HPLC) using a Kromasil C18 column, a mobile phase of a mixture of methanol and water (3:1 ratio), and a detection wavelength of 254 nm.

[0037] Hydrogenation efficiency and selectivity are calculated based on the following formulas.

[0038]

[0039] in B Hydrogenation efficiency (g·L) -1 ). C KMnO4 The concentration of potassium permanganate solution (mol·L) -1 ), V KMnO4 This represents the volume (mL) of the potassium permanganate solution. V H2O2 This represents the volume (mL) of hydrogen peroxide. M H2O2 is the molar mass of hydrogen peroxide.

[0040] Example 1:

[0041] The spiral structured packing is made of cast iron, with a solid circular cross-section spiral coil of 2mm wire diameter and 1.5mm spiral gap. The outer diameter is 12mm, and the packing height is 0.4m. It is installed in a 40mm diameter reactor. A gas-liquid-solid three-phase reaction is carried out using an anthraquinone hydrogenation system. The anthraquinone working solution, thoroughly mixed with catalyst particles, is fed from the top of the reactor at a rate of 40ml / min. Hydrogen gas is also fed from the top of the reactor. The anthraquinone solution and hydrogen gas undergo a co-current contact reaction within the reactor. The reactor operating pressure is 0.3MPa, and the reaction temperature is 60℃. The reaction products are collected from the liquid phase outlet. The reaction is continuously circulated for 60 minutes, and the hydrogenation efficiency is measured to be 3.4g·L⁻¹. -1 ·gcat -1 The reaction selectivity is 97%.

[0042] Example 2:

[0043] The spiral structured packing is made of cast iron, with a solid circular cross-section spiral coil of 2mm wire diameter and 2mm spiral gap. The outer diameter is 12mm, and the packing height is 0.4m. It is installed in a 40mm diameter reactor. A gas-liquid-solid three-phase reaction is carried out using an anthraquinone hydrogenation system. The anthraquinone working solution, thoroughly mixed with catalyst particles, is fed from the top of the reactor at 50ml / min. Hydrogen gas is also fed from the top of the reactor. The anthraquinone solution and hydrogen gas undergo a co-current contact reaction within the reactor. The reactor operating pressure is 0.3MPa, the reaction temperature is 60℃, and the reaction products are collected from the liquid phase outlet. The reaction is continuously circulated for 60 minutes, and the hydrogenation efficiency is measured to be 1.8g·L⁻¹. -1 ·gcat -1 The reaction selectivity is 98%.

[0044] Example 3:

[0045] The spiral structured packing is made of cast iron, with a solid circular cross-section spiral coil of 2mm wire diameter and 2.5mm spiral gap, an outer diameter of 12mm, and a packing height of 0.4m. It is installed in a 40mm diameter reactor. A gas-liquid-solid three-phase reaction is carried out using an anthraquinone hydrogenation system. The anthraquinone working solution, thoroughly mixed with catalyst particles, is fed from the top of the reactor at a rate of 60ml / min. Hydrogen gas is also fed from the top of the reactor. The anthraquinone solution and hydrogen gas undergo a co-current contact reaction within the reactor. The reactor operating pressure is 0.3MPa, the reaction temperature is 60℃, and the reaction products are collected from the liquid phase outlet. The reaction is continuously circulated for 60 minutes, and the hydrogenation efficiency is measured to be 1.6g·L⁻¹. -1 ·gcat -1 The reaction selectivity is 98%.

[0046] Example 4:

[0047] The spiral structured packing is made of cast iron, with a solid circular cross-section spiral coil with a wire diameter of 1.5 mm, a spiral gap of 2 mm, an outer diameter of 12 mm, and a packing height of 0.4 m. It is installed in a reactor with a diameter of 40 mm. A gas-liquid-solid three-phase reaction is carried out using an anthraquinone hydrogenation system. The anthraquinone working solution, thoroughly mixed with catalyst particles, is fed from the top of the reactor at a rate of 50 ml / min. Hydrogen gas is also fed from the top of the reactor. The anthraquinone solution and hydrogen gas undergo a co-current contact reaction within the reactor. The reactor operating pressure is 0.3 MPa, the reaction temperature is 60 °C, and the reaction products are collected from the liquid phase outlet. The reaction is continuously circulated for 60 minutes, and the hydrogenation efficiency is measured to be 3.2 g·L⁻¹. -1 ·gcat -1 The reaction selectivity is 96%.

[0048] Example 5:

[0049] The spiral structured packing is made of cast iron, with a solid circular cross-section spiral coil with a wire diameter of 2.5 mm and a spiral gap of 2 mm. The outer diameter is 12 mm, and the packing height is 0.4 m. It is installed in a 40 mm diameter reactor. A gas-liquid-solid three-phase reaction is carried out using an anthraquinone hydrogenation system. The anthraquinone working solution, thoroughly mixed with catalyst particles, is fed from the top of the reactor at a rate of 50 ml / min. Hydrogen gas is also fed from the top of the reactor. The anthraquinone solution and hydrogen gas undergo a co-current contact reaction within the reactor. The reactor operating pressure is 0.3 MPa, the reaction temperature is 60 °C, and the reaction products are collected from the liquid phase outlet. The reaction is continuously circulated for 60 minutes, and the hydrogenation efficiency is measured to be 1.4 g·L⁻¹. -1 ·gcat -1 The reaction selectivity is 97%.

[0050] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the inventive concept, and these all fall within the protection scope of the present invention.

Claims

1. A novel slurry bed reactor, characterized in that, include: The reactor shell (1) is placed vertically and is a cylindrical sleeve structure with an outer jacket. The jacket is provided with a heat transfer oil outlet (7) and a heat transfer oil inlet (8). The spiral packing (2) is vertically installed in the internal cavity of the reactor shell (1). Its upper end is fixed to the inner tube of the fluid distribution system (3), and its lower end hangs freely. The spiral packing (2) is formed by continuously winding a single metal wire along a spiral trajectory with equal diameter and equal pitch to form a vertical spiral structure with uniform spiral gap. This forms a channel for the slurry liquid phase to flow downward along the spiral trajectory under the action of gravity, so as to realize gas-liquid mass transfer and catalytic reaction. The fluid distribution system (3) is located above the reactor shell (1) and is a semi-closed hollow sleeve structure with an open bottom. It has a gas phase inlet (5) and a liquid phase inlet (6), and a gas phase distribution port is provided on its inner tube wall. The fluid distribution system (3) is sealed to the upper end of the reactor shell (1). Reactor base (4): Located below the reactor shell (1), it is a semi-closed tubular structure with an open top, and is provided with a gas phase outlet (9), a liquid phase outlet (10) and a temperature sensor interface (11). The reactor base (4) is sealed to the lower end of the reactor shell (1).

2. The novel slurry bed reactor according to claim 1, characterized in that: The spiral packing (2) has a circular cross-section with a diameter of 1.5 mm to 2.5 mm, a spiral outer diameter of 10 mm to 14 mm, a pitch of 1.5 mm to 2.5 mm, and a height of 350 mm to 450 mm.

3. The novel slurry bed reactor according to claim 1, characterized in that: The ratio of the height of the reactor shell (1) to its outer cross-sectional diameter is 35:9 to 45:9; the ratio of the diameter of the internal cavity cross-section of the reactor shell (1) to its outer cross-sectional diameter is 3:9 to 5:

9.

4. The novel slurry bed reactor according to claim 1, characterized in that: The opening diameter of the heat transfer oil inlet (8) and heat transfer oil outlet (7) is 5 mm to 7 mm.

5. The novel slurry bed reactor according to claim 1, characterized in that: The ratio of the outer diameter of the inner tube to the inner diameter of the outer tube of the fluid distribution system (3) is 1:2.5 to 1:3.5; the opening diameter of the gas phase inlet (5) is 5 mm to 7 mm; the opening diameter of the liquid phase inlet (6) is 2 mm to 4 mm; and the opening diameter of the gas phase distribution port (23) is 3 mm to 5 mm.

6. The novel slurry bed reactor according to claim 1, characterized in that: The opening diameter of the gas phase outlet (9) is 5 mm to 7 mm; the opening diameter of the liquid phase outlet (10) is 5 mm to 7 mm; and the opening diameter of the sensor interface (11) is 2 mm to 4 mm.

7. A method for performing a gas-liquid-solid three-phase catalytic reaction using the novel slurry bed reactor according to any one of claims 1 to 6, characterized in that, The gaseous reactants are introduced into the reactor through the gas phase inlet (5) of the fluid distribution system (3), and after being distributed through the gas phase distribution port, they flow into the interior of the reactor shell (1). The slurry liquid phase containing catalyst particles enters from the liquid phase inlet (6) of the fluid distribution system (3) and is guided to be distributed to the surface of the spiral packing (2). Under the action of gravity, the slurry liquid phase flows downward along the spiral trajectory of the spiral packing (2) to form a liquid bridge. The downward flowing slurry liquid phase and the upward or parallel flowing gaseous reactants undergo gas-liquid mass transfer in the gaps and on the surface of the spiral packing (2). The gaseous reactants after mass transfer diffuse to the surface of the catalyst particles suspended in the slurry liquid phase to carry out a catalytic reaction. The tail gas after the reaction leaves the reactor from the gas phase outlet (9) of the reactor base (4). The slurry liquid phase product after the reaction leaves the reactor from the liquid phase outlet (10) of the reactor base (4).

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