CN104907011A - Gas regulation and control internal circulation slurry bed circulation reactor - Google Patents

Abstract

A gas-regulated internal circulation slurry bed loop reactor, including a reactor cylinder, a central downcomer, a gas chamber, a gas injection hole, a liquid collector, a deflector, a distribution baffle, a gas distributor, and a primary inlet pipe , secondary air inlet pipe, liquid distributor, liquid inlet pipe, slag discharge port, liquid discharge port, axial flow cyclone, reactant outlet, etc.; the reactor cylinder is axially equipped with a central downcomer, and the upper part of the downcomer is connected to the liquid collection An annular air chamber is arranged around the lower part of the air chamber, and an obliquely downward injection hole is arranged on the side wall of the central downcomer in the air chamber. The air inlet of the air chamber is connected with the secondary air inlet pipe; The gas distributor set under the baffle is connected to the primary inlet pipe; the slag discharge port is set in the middle of the gas distributor; the liquid discharge port is set at the bottom of the reactor cylinder; the liquid distributor is set between the gas distribution plate and the distribution baffle and connected with the inlet The liquid pipe is connected; the upper part of the reactor cylinder is provided with a deflector and an axial flow cyclone in sequence, and a reactant outlet is provided at the top.

Description

A gas-regulated internal circulation slurry bed loop reactor

1. Technical field

The invention provides a gas-regulated internal circulation slurry bed loop reactor, which relates to the catalytic hydrogenation reaction process of biological oil, coal tar or petroleum liquid phase in the field of chemical industry.

2. Background technology

Catalytic hydrotreating of bio-oil, coal tar or petroleum is one of the common methods to improve the quality and added value of oil products. Liquid-phase hydrogenation utilizes the high-temperature and high-pressure hydrogen dissolving properties of liquids to carry hydrogen through a large amount of liquid circulation to achieve efficient hydrogenation reactions, avoiding the use of hydrogen circulation compressors and high and low pressure separators for liquid and hydrogen after the reaction, which simplifies the process flow and high-pressure equipment The quantity is reduced by more than 70%, which greatly reduces the energy consumption and investment of hydrogenation, which is the development direction of the future oil hydrogenation process. At present, the commonly used liquid-phase hydrogenation reactors for oil products include fixed-bed reactors and ebullated-bed reactors with forced external circulation, and slurry-bed loop reactors under development. The advantages of the fixed bed reactor are simple structure, easy loading of large particle catalysts, small wear and tear, catalyst bed activity decreases layer by layer, high activity period is long, and easy to operate. The small effective contact area between the large-particle catalyst and the gas-liquid leads to low hydrogenation efficiency, large liquid circulation and difficulty in catalyst replacement. In order to eliminate the defects of the fixed bed reactor, the ebullating bed reactor adopts powder catalyst and fluidization technology, so that the gas-liquid-solid contact is fully mixed and uniform, and the hydrogenation efficiency is high. There is basically no dead angle or stagnation area in the reactor, and the coking phenomenon is reduced. , The catalyst is easy to replace. Fixed-bed reactors and ebullated-bed reactors with forced external circulation are equipped with a liquid circulation pump and a hydrogen dissolving mixer outside the reactor to force the liquid material to circulate and carry hydrogen, greatly increasing the mixing of hydrogen and liquid materials in the hydrogen dissolving mixer The speed and degree of dissolution can greatly improve hydrogenation efficiency, avoid hydrogen circulation and use high-energy hydrogen circulation compressors, but this requires circulation pumps to withstand harsh conditions such as high temperature, high pressure, gas-liquid-solid three-phase materials, and hydrogen corrosion. Conditions, circulating pumps are expensive and risky in long-term operation, which has become a bottleneck restricting the application and promotion of oil liquid phase hydrogenation technology.

The slurry bed loop reactor is another high-efficiency multiphase reactor developed on the basis of the ebullating bed reactor. It uses the density difference between the inside and outside of the fluid circulation area to realize the internal circulation of liquid materials, and avoids the use of external circulation pumps to force material circulation. It is not only suitable for high-viscosity oil materials with a large amount of treatment, but also conducive to the heterogeneous reaction between gas-liquid-solid. It also has the advantages of simple structure, low cost, and long-term operation. Ideal reactor for hydrogen. At present, the most common is the loop reactor with descending circulation in the annular area. The larger the reactor capacity is, the larger the diameter is, and the larger the flow area of the annular area is, the liquid circulation speed is greatly reduced, and the residence time is prolonged; in addition, the oil contact The surface area of the wall increases, and the probability of oil coking increases greatly, which is also the main bottleneck in the industrial application of heavy oil suspension bed hydrogenation. The loop reactor with descending circulation in the center tube overcomes the defects of the descending circulation in the annular area structurally, and is suitable as a large-capacity slurry bed reactor. However, compared with the forced circulation ebullating bed reactor, the liquid The low flow rate leads to low liquid circulation rate, which cannot meet the requirements of large circulation volume of liquid-phase hydrogenation. In addition, the hydrogen dispersion, mixing and dissolution properties are poor, and the hydrogenation conversion efficiency needs to be improved. Therefore, it is urgent to develop a new type of loop reactor with high liquid circulation rate and excellent hydrogen miscibility to meet the circulation needs of liquid phase hydrogenation of oil products, increase the contact area and turbulent intensity of gas-liquid-solid three-phase, and improve solid fluidization. Uniformity of distribution, enhanced mass transfer and heat transfer, improved hydrogenation reaction efficiency, avoiding coking and improving reactor processing capacity.

3. Contents of the invention

The object of the present invention is to overcome the shortcomings of existing forced circulation suspended bed reactors and loop reactors, and invent a gas-regulated internal circulation slurry bed loop reactor, which is suitable for small and medium-sized liquid phase hydrogenation devices. By setting multiple high-speed gas injection holes in the lower part of the central downcomer, the hydrogen gas is sprayed at a high speed through the gas injection holes in the lower part of the central downcomer after being stabilized and uniformly flowed by the annular gas chamber, and the suction liquid is forced to circulate to strengthen the interaction between hydrogen and oil. Mix and dissolve to eliminate coking in the descending circulation area; the gas is divided into two stages of feed, and the ratio of the feed to the liquid is used to control the ratio of the circulating liquid to improve the efficiency of liquid-phase hydrogenation.

Technical scheme of the present invention:

A gas-regulated internal circulation slurry bed loop reactor, including a reactor cylinder, a central downcomer, a gas chamber, a gas injection hole, a liquid collector, a deflector, a distribution baffle, a gas distributor, and a primary inlet pipe , secondary air inlet pipe, liquid distributor, liquid inlet pipe, slag discharge port, liquid discharge port, axial flow cyclone, reactant outlet, etc.; a central downcomer is set in the axial middle of the reactor cylinder, and the upper part of the central downcomer is connected to Conical liquid collector; the periphery of the lower part of the central downcomer is connected with the coaxial annular air chamber, and the side wall of the central downcomer in the air chamber is provided with two or more rows of obliquely downward gas injection holes, and the air inlet of the air chamber It is connected to the secondary inlet pipe of the reactor cylinder; the outlet of the central downcomer is facing the distribution baffle; the gas distributor installed under the distribution baffle is connected to the primary inlet pipe of the reactor cylinder, and the slag discharge is set in the middle of the gas distributor outlet; the bottom of the reactor cylinder is provided with a liquid discharge port; a liquid distributor is provided between the gas distribution plate and the distribution baffle and connected to the liquid inlet pipe of the reactor cylinder; the top of the central downcomer is provided with a liquid collector, and the reactor cylinder The upper part is provided with a deflector and an axial flow cyclone in sequence, and the area of the annular channel between the liquid collector and the deflector is larger than the annular area of the reactor cylinder and the central downcomer; the reactant outlet is arranged on the top of the reactor cylinder.

4. Description of drawings

Accompanying drawing is the equipment structural diagram of invention. Among them: Fig. 1 is an overall view of a gas-regulated internal circulation slurry bed loop reactor; Fig. 2 is a top view of an annular gas chamber; Fig. 3 is a cross-sectional view of an annular gas chamber.

Among them: 1. Reactor cylinder; 2. Central downcomer; 3. Gas chamber; 4. Gas injection hole; 5. Liquid collector; 6. Deflector; 7. Distribution baffle; 8. Gas distributor; 9. Primary inlet pipe; 10. Secondary inlet pipe; 11. Liquid inlet pipe; 12. Liquid discharge port; 13. Slag discharge port; 14. Reactant outlet; 15. Liquid distributor; 16. Axial flow spinner device.

5. Specific implementation

The present invention will be described in detail below in conjunction with accompanying drawing: a kind of gas control internal circulation slurry bed loop reactor, comprises reactor shell (1), central downcomer (2), gas chamber (3), gas injection hole ( 4), liquid collector (5), deflector (6), distribution baffle (7), gas distributor (8), primary air inlet pipe (9), secondary air inlet pipe (10), liquid inlet pipe (11), liquid discharge port (12), slag discharge port (13), reactant outlet (14), liquid distributor (15), axial flow cyclone (16), etc.; A central downcomer (2) is arranged in the middle, and the upper part of the central downcomer (2) is connected to a conical liquid collector (5); the lower part of the central downcomer (2) is connected to its coaxial annular air chamber (3), and the air chamber ( 3) There are two or more rows of obliquely downward gas injection holes (4) on the side wall of the central downcomer (2), and the air inlet of the gas chamber (3) is connected with the two sides of the reactor cylinder (1). The outlet of the central downcomer (2) faces the distribution baffle (7); the gas distributor (8) arranged under the distribution baffle (7) is connected to the first stage of the reactor cylinder (1) The gas inlet pipe is connected (9), and the slag outlet (13) is arranged in the middle of the gas distributor (8); the liquid outlet (12) is arranged at the bottom of the reactor cylinder (1); the gas distribution plate (8) and the distribution baffle (7) ) between the liquid distributor (15) and connected with the liquid inlet pipe (11) of the reactor cylinder (1); the top of the center downcomer (2) is provided with a liquid collector (5), and the reactor cylinder (1) The upper part is provided with a deflector (6) and an axial flow cyclone (16) in sequence, and the area of the annular passage between the liquid collector (5) and the deflector (6) is larger than that of the reactor cylinder (1) and the central downcomer The annular area of (2); the reactant outlet (14) is arranged on the top of the reactor shell (1).

The included angle of liquid collector (5) is 60-120 °.

The gas injection holes (4) are evenly distributed on the periphery of the central downcomer (2), and are 10-45° to the axial direction of the central downcomer (2); the opening ratio of the gas injection holes (4) is the central downcomer (2 ) of 1%-10% of the cross-sectional area; the diameter of the gas injection hole (4) is 3-6mm.

The cone angle of distribution baffle (7) is 90-150 °.

The ratio of the vertical distance between the distribution baffle (7) and the lower part of the central descending pipe (2) to the diameter of the central descending pipe (2) is 1-1.5.

The gas distributor (8) can be a kind of existing or newly developed gas distributor, preferably a sieve plate type gas distributor.

The diameter ratio of the reactor barrel (1) to the central downcomer (2) is 1.8-2.5.

The diameter of the lower edge of the deflector (6) is 1/3-2/3 of the diameter of the reactor cylinder (1).

The diameter of the upper edge of the liquid collector (5) is 0-400mm larger than the diameter of the lower edge of the deflector (6).

The ratio of the vertical distance between the upper edge of the liquid collector (5) and the lower edge (6) of the deflector to the diameter of the deflector is 1-1.5.

The specific technical route is: coal tar, bio-oil or petroleum raw material oil with fresh catalyst enters the reactor cylinder (1) from the liquid inlet pipe (12), and is evenly dispersed by the liquid distributor (15) and the distribution baffle (7) Then flow from bottom to top; the hydrogen enters the reactor cylinder (1) in two streams, and one stream is uniformly dispersed from the first-stage inlet pipe (9) through the gas distributor (8) and then contacts with the reaction oil and the catalyst for drumming. Bubble mass transfer reaction; another stream from the secondary air intake pipe (10) passes through the air chamber (3) through the obliquely downward gas injection hole (4) into the central downcomer (2) at high speed, under the suction of the airflow , the catalyst-containing reaction oil flows into the liquid collector (5) from the annular gap between the reactor cylinder (1) and the central downcomer (2) and moves downward rapidly in the central downcomer (2); The foamy flow ejected from the downcomer (2) is dispersed to the periphery under the guidance of the baffle (7), and then turns back into the annular gap between the reactor cylinder (1) and the central downcomer (2) to move upward. Part of the catalyst-containing reaction oil flows into the liquid collector (5) and moves downward to form a rapid circulation, and the other part settles the catalyst under the action of the deflector (6) and the axial flow cyclone (16) and then exits the reactant outlet ( 14) Draining: a liquid discharge port (15) is provided at the bottom of the reactor cylinder (1) for liquid discharge during shutdown maintenance or irregular slag discharge.

A gas-regulated internal circulation slurry bed loop reactor provided by the present invention has the following characteristics:

(1) By setting two or more rows of obliquely downward gas injection holes around the lower part of the central downcomer, the hydrogen gas is evenly distributed and flows stably from the gas chamber, and then injected into the central downcomer from the gas injection holes at high speed, and the suction liquid is forced to circulate , strengthen the mixing and dissolving of hydrogen and oil, increase the circulation rate and hydrogen dissolving capacity of the liquid in the reactor, eliminate coking in the descending circulation area, prolong the gas-liquid-solid three-phase contact time, improve the reaction efficiency, and do not need oil External circulation, eliminating the need for expensive external circulation pumps, greatly reducing the risk of long-term reactor operation.

(2) The gas is divided into two stages of feed, and the ratio of the feed is used to realize the ratio control of the circulating liquid and improve the efficiency of liquid-phase hydrogenation, which is suitable for small and medium-sized liquid-phase hydrogenation devices.

In particular, the gas-regulated internal circulation slurry bed loop reactor can not only be used in the liquid phase hydrogenation reaction process of oil products, but also can be used in other chemical reaction processes and sewage treatment.

Claims (8)

1. A gas-regulated internal circulation slurry bed loop reactor, including a reactor cylinder, a central downcomer, a gas chamber, a gas injection hole, a liquid collector, a deflector, a distribution baffle, a gas distributor, and a first-stage Air inlet pipe, secondary air inlet pipe, liquid distributor, liquid inlet pipe, slag discharge port, liquid discharge port, axial flow cyclone, reactant outlet, etc. It is characterized in that a central descending pipe is set in the axial middle of the reactor cylinder, The upper part of the central downcomer is connected to the conical liquid collector; the periphery of the lower part of the central downcomer is connected with the coaxial annular air chamber, and the side wall of the central downcomer in the air chamber is provided with two or more rows of obliquely downward gas injection holes. The air inlet of the chamber is connected to the secondary air intake pipe of the reactor cylinder; the outlet of the central downcomer is facing the distribution baffle; the gas distributor set under the distribution baffle is connected to the primary air intake pipe of the reactor cylinder, and the gas distribution Set a slag discharge port in the middle of the reactor; set a liquid discharge port at the bottom of the reactor cylinder; set a liquid distributor between the gas distribution plate and the distribution baffle and connect it to the liquid inlet pipe of the reactor cylinder; set a liquid collector at the top of the central downcomer , the upper part of the reactor cylinder is provided with a deflector and an axial flow cyclone in sequence, and the area of the annular channel between the liquid collector and the deflector is larger than the annular area of the reactor cylinder and the central downcomer; the top of the reactor cylinder is set Reactant outlet. 2. A gas-regulated internal circulation slurry bed loop reactor according to claim 1, characterized in that the included angle of the liquid collector is 60-120°. 3. A gas-regulated internal circulation slurry bed loop reactor according to claim 1, characterized in that the gas injection holes are evenly distributed around the central downcomer, and are 10-45° from the central downcomer axial direction; The opening rate of the gas injection hole is 1%-10% of the cross-sectional area of the central downcomer; the diameter of the gas injection hole is 3-6mm. 4. A gas-regulated internal circulation slurry bed loop reactor according to claim 1, characterized in that the cone angle of the distribution baffle is 0-180°, preferably 90-150°; the distribution baffle and the central downcomer The ratio of the vertical distance of the lower part to the diameter of the central downcomer is 1-1.5. 5. A gas-regulated internal circulation slurry bed loop reactor according to claim 1, characterized in that the diameter ratio of the reactor cylinder to the central downcomer is 1.8-2.5. 6. A gas-regulated internal circulation slurry bed loop reactor according to claim 1, characterized in that the diameter of the lower edge of the deflector is 1/3-2/3 of the diameter of the reactor cylinder. 7. A gas-regulated internal circulation slurry bed loop reactor according to claim 1, characterized in that the diameter of the upper edge of the liquid collector is 0-400mm larger than the diameter of the lower edge of the deflector. 8. A gas-regulated internal circulation slurry bed loop reactor according to claim 1, characterized in that the ratio of the vertical distance between the upper edge of the liquid collector and the lower edge of the deflector to the diameter of the deflector is 1 -1.5.