WO2017008720A1

WO2017008720A1 - Apparatus for strengthening gas-liquid mass transfer of bubbling bed hydrogenation reactor

Info

Publication number: WO2017008720A1
Application number: PCT/CN2016/089683
Authority: WO
Inventors: 陈强; 蔡连波; 李小婷; 盛维武; 赵晓青; 郭西春
Original assignee: 中石化炼化工程（集团）股份有限公司
Priority date: 2015-07-10
Filing date: 2016-07-11
Publication date: 2017-01-19
Also published as: CN105038845A; CN105038845B

Abstract

An apparatus for strengthening the gas-liquid mass transfer of a bubbling bed hydrogenation reactor, mainly comprising a main body tube (1) and a filling tube (4) which is in communication with the main body tube (1), wherein oil is contained in the main body tube (1), and the filling tube (4) is used for filling surface active substances into oil in the main body tube (1). By filling a surface active substance into an oil, the surface tension from the two-phase interface can be remarkably reduced, and the bubbling properties of a system are strengthened; since the shapes of air bubbles affect the instantaneous rising velocity of the air bubbles, when the surface active substance is filled into the oil, the shapes of the air bubbles further can be effectively controlled, and the air bubbles are inhibited from being deformed; and a height-width ratio and the shapes of the air bubbles tend to be stable due to a proper amount of the surface active substance, so that the rising velocity of the air bubbles is reduced, thereby increasing the stabilization time of the air bubbles in the oil, and strengthening the gas-liquid mass transfer.

Description

Device for enhancing gas-liquid mass transfer in bubbling bed hydrogenation reactor

Technical field

The invention relates to the technical field of gas-liquid mass transfer, in particular to a device for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor.

Background technique

Hydrocracking, as one of the most effective ways to lighten heavy oil, is widely used in improving oil utilization and upgrading oil quality. Different reactor types and hydrogenation processes are usually selected according to the difference in hydrodynamic properties of different reaction materials. At present, the most widely used ones are fixed bed hydrogenation reactors, moving bed hydrogenation reactors, bubbling beds (suspended bed and bubbling bed) hydrogenation reactors, and the like. Among them, the fluidized bed has become one of the important means for the light weight of heavy oil because of its wide adaptability to raw materials and flexible operation. Since 2000, more than one new bed of fluidized bed hydrocracking device has been built in foreign countries to meet the needs of deep processing of inferior heavy crude oil. At present, the introduction of foreign advanced suspended bed and fluidized bed hydrogenation technology is also being carried out in China, and the suspension bed and fluidized bed hydrogenation technology with independent intellectual property rights are also independently developed.

The specific process of the suspension bed and the bubbling bed hydrogenation is as follows: after the reaction feedstock oil is mixed with hydrogen, it enters from the bottom of the reactor, and the catalyst particles are suspended or boiled by internal circulation of the gas-liquid fluid in the reactor.

At present, the amount of gas in the reactor (ie, gas holdup) is generally used as one of the important indicators to measure the mass transfer of gas and liquid in such hydrogenation process. Under the same gas holdup condition, the bubble size and its probability distribution have an important influence on the mass transfer performance between gas and liquid solid phase. When the gas content is the same, the gas The smaller the bubble diameter, the larger the total area of the gas-liquid phase, the faster the mass transfer rate; the larger the bubble diameter, the smaller the total gas-liquid phase area and the slower the mass transfer rate. At the same time, the rising speed of the large bubbles is higher than that of the small bubbles, which also causes the residence time of the gas in the reactor to be shortened, and a gas short circuit is formed to some extent. These will affect the mass transfer between the reactants and reduce the conversion rate of the reaction.

In addition, after the microbubbles are formed in the oil, the stabilization time of the microbubbles in the oil is another important indicator for measuring the mass transfer of the gas and liquid in the hydrogenation process. In the existing bubbling bed hydrogenation process, micro The bubble flow has a shorter settling time in the oil.

Summary of the invention

It is an object of the present invention to provide an apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor to solve the technical problem of short microbubble flow stabilization time in the prior art.

The present invention provides an apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor, comprising a main body tube and a filling tube in communication with the main body tube, the main body tube containing oil, the filling The tube is used to fill the oil in the body tube with a surfactant.

Further, the filling tube includes a surface active material filling tube and a surface active material dispersing tube which are in communication with each other, the surface active material dispersing tube is located in the main body tube, and the surface active material dispersing tube is provided with a plurality of The pores are distributed, and the surfactant dispersion tube is used to disperse the surface active material in the oil.

Further, the surface active material dispersion tube has a ring shape, and a circumferential direction of the surface active material dispersion tube is disposed perpendicular to a longitudinal direction of the body tube.

Further, the apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor further comprises a microbubble generator comprising a microporous tube and an inlet tube, wherein the microporous tube is located The main body tube is in communication with the main body tube, and the intake pipe is in communication with the microporous tube.

Further, both ends of the microporous tube are respectively connected to the inner wall of the main body tube.

Further, the first end of the intake pipe is located outside the main pipe, the second end of the intake pipe is connected to the outer wall of the main pipe, and the second end of the intake pipe and the microporous pipe The air intake space is formed.

Further, the microporous tube is a venturi microporous tube.

Further, the longitudinal section of the venturi microporous tube is two elliptical or two trapezoidal symmetry about the axis of the main body tube.

Further, the axis of the intake pipe is constricted to the center of the venturi microporous tube.

Further, the microporous tube is made of sintered metal powder.

By adding a surface active substance to the oil, the invention can significantly reduce the surface tension between the two-phase interface and enhance the foaming performance of the system; and the surface activity of the oil is added due to the instantaneous speed of the bubble rising due to the shape of the bubble. The substance can also effectively regulate the shape of the bubble and inhibit the deformation of the bubble. The appropriate amount of the surface active material can stabilize the aspect ratio and shape of the bubble, reduce the rising speed of the bubble, thereby improving the stability time of the bubble in the oil, and strengthening Gas-liquid mass transfer.

DRAWINGS

In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings to be used in the specific embodiments or the description of the prior art will be briefly described below, and obviously, the attached in the following description The figures are some embodiments of the invention, for the field For the sake of the skilled person, other drawings can be obtained from these drawings without any creative work.

1 is a schematic structural view of an apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor according to an embodiment of the present invention;

2 is a schematic view showing the structure of the filling tube and the surface active material dispersing tube of FIG. 1.

Reference mark:

The main body pipe 1, the intake pipe 2, the venturi porous pipe 3, the intake space 31, the filling pipe 4, the surface active material filling pipe 41, the surface active material dispersing pipe 42, and the distribution hole 43.

detailed description

The technical solutions of the present invention will be clearly and completely described in the following with reference to the accompanying drawings. It is obvious that the described embodiments are a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

In the description of the present invention, it is to be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. The orientation or positional relationship of the indications is based on the orientation or positional relationship shown in the drawings, and is merely for the convenience of the description of the invention and the simplified description, rather than indicating or implying that the device or component referred to has a specific orientation, in a specific orientation. The construction and operation are therefore not to be construed as limiting the invention. Moreover, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

In the description of the present invention, it should be noted that the terms "installation", "connected", and "connected" are to be understood broadly, and may be fixed or detachable, for example, unless otherwise explicitly defined and defined. Connected, or integrally connected; can be mechanical or electrical; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of the two components. The specific meaning of the above terms in the present invention can be understood in a specific case by those skilled in the art.

1 is a schematic structural view of an apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor according to an embodiment of the present invention; FIG. 2 is a filling tube 4 and a surface active material dispersing tube 42 of FIG. Schematic. As shown in FIG. 1 and FIG. 2, the present invention provides an apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor, comprising a main body tube 1 and a filling tube 4 communicating with the main body tube 1, The main body tube 1 contains oil, and the filling tube 4 is for filling a surface active material with the oil in the main body tube 1. The main body tube 1 may be a round tube, and may be an integral tube or a multi-part combination tube. The whole may be a straight tube, or one or more of the sections may be designed as a curved tube as needed. When the main body tube 1 is a multi-part combination tube, the installation of the inner member is convenient.

Wherein, the surface active material may be an anionic, cationic, nonionic and amphoteric surfactant, or a composite surfactant prepared by compounding a plurality of surfactants. The surfactant has a structure of one end oleophilic and one end oleophobic. The oleophilic end of the surfactant molecule is aligned on the surface of the reaction material to reduce the surface tension, enhance the foaming performance, and promote the dispersion of hydrogen in the reaction material, and at the same time, the surface The active agent can reduce the bubble diameter, stabilize the foaming property, and reduce the bubble rising speed.

By adding a surface active substance to the oil, the invention can significantly reduce the surface tension between the two-phase interface and enhance the foaming performance of the system; the instantaneous speed of the bubble rises due to the shape of the bubble Degree, the surface active material is added to the oil, and the shape of the bubble can be effectively regulated to suppress the deformation of the bubble. The appropriate amount of the surface active material can stabilize the aspect ratio and shape of the bubble, and reduce the rising speed of the bubble, thereby improving The stable time of the bubbles in the oil enhances the gas-liquid mass transfer.

Further, the filling tube 4 includes a surface active material filling tube 41 and a surface active material dispersing tube 42 which are in communication with each other, and the surface active material dispersing tube 42 is located in the main body tube 1 and the surface active material is dispersed. The tube 42 is provided with a plurality of distribution holes 43 for dispersing the surface active material in the oil. The distribution holes 43 may be provided on one side of the surface active material dispersion tube 42, or may be provided on both sides of the surface active material dispersion tube 42. The number and diameter of the distribution holes 43 can be set as needed. Generally, the number of distribution holes 43 is 6-12 and the diameter is between 3-6 mm.

Wherein, the surfactant filling tube 41 may be a straight tube as shown in FIG. 2, and the longitudinal direction of the surface active material filling tube 41 is disposed in a circumferential straight tube of the annular surface active material dispersing tube 42 to facilitate rapid surface active material. It is filled into the surfactant dispersion tube 42.

Further, as shown in FIG. 2, the surface active material dispersing tube 42 is annular, for example, circular or square, and the circumferential direction of the surface active material dispersing tube 42 is perpendicular to the longitudinal direction of the main tube 1. To quickly and uniformly disperse the surface active material in the oil. Preferably, the distribution holes 43 are evenly distributed along the circumferential direction of the dispersion pipe to uniformly disperse the surface active material in the oil.

The apparatus for enhancing the gas-liquid mass transfer of the bubbling bed hydrogenation reactor in this embodiment further comprises a microbubble generator comprising a microporous tube and an inlet tube 2, the microporous tube being located at the The main body tube 1 is in communication with the main body tube 1, and the intake pipe 2 is in communication with the microporous tube. A plurality of micropores are distributed on the microporous tube, and the pore size range of the micropores can be required by the specific hydrogenation process And the change is generally between 30 microns and 500 microns. The bubbles generated by the microbubble generator in the microporous tube portion generally belong to the micron-sized bubbles.

The device for enhancing the gas-liquid mass transfer of the bubbling bed hydrogenation reactor provided by the invention has the advantages of stable and high efficiency of the bubble generator, good gas-liquid mixing characteristics and small pressure drop, and the hydrogen in the hydrogenation process can be in the form of microbubbles. Stable diffusion in the liquid stream, sufficient depth mixing, rapid dissolution into the liquid stream, stable and uniform bubble flow in the case of deep saturation, the application value in the gas-liquid mixing field is obvious.

The invention adds the surface active material to the main body tube 1 through the filling tube 4, and mixes with the liquid phase oil; the mixed liquid phase flow enters the microbubble generator, and forms a large number of bubbles on the outer surface of the microporous tube, and the bubbles The diameter can be controlled between 200 nm and 100 microns, and the gas holdup (the percentage of the gas phase in the volume of the gas-liquid mixture) can be increased to more than 50%. The bubbles are suspended in the liquid to form a relatively stable bubble flow without the rapid gas and liquid flow. The condition of separation. In the invention, since the surface active material is added, most of the microbubbles generated by the bubble generator are dissolved, and some of the microbubbles are stably flowed with the liquid flow, and no gas-liquid layering or segmentation is formed, and the flow pattern is stable and uniform, and the flow is stable. The resistance is small.

Further, for ease of installation, preferably, both ends of the microporous tube are respectively connected to the inner wall of the main body tube 1. Specifically, the venturi microporous tube can be welded to the inner wall of the main body tube 1.

Further, the first end of the intake pipe 2 is located outside the main body pipe 1, and the second end of the intake pipe 2 is connected to the outer wall of the main pipe 1, in particular, the intake pipe 2 can be welded to the main pipe An outer side of the intake pipe 2 forms an intake space 31 between the second end of the intake pipe 2 and the microporous pipe. As shown in FIG. 1, an annular gap is formed between the venturi microporous pipe and the main pipe 1. Air space 31. The intake pipe 2 in this embodiment is an outer pipe which does not need to protrude into the central portion of the main pipe 1 and has no gas-liquid contact function, so that the gas cone and wall suction effect caused by the central intake pipe 2 can be completely avoided.

Further, the microporous tube is a venturi microporous tube. That is, the microporous tube in this embodiment is a venturi-shaped microporous tube. On the one hand, the venturi microporous tube utilizes the characteristics of porous media to realize multi-point microporous air intake; on the other hand, the principle of pressure change of the venturi tube is used, and the bubble is sucked and sucked, so that the bubble rapidly deviates from the inner wall of the venturi during growth. Microbubbles can be quickly removed to ensure that as many microbubbles as possible are created to enhance the formation and mixing of microbubbles.

Specifically, as shown in FIG. 1 , the minimum inner diameter d of the venturi microporous tube is generally one third to three quarters of the inner diameter D of the main tube 1 , and the length L of the venturi microporous tube is generally the main tube 1 . One to five times the inner diameter D.

Further, the longitudinal section of the venturi microporous tube is two elliptical or two trapezoidal symmetry about the axis of the main body tube 1. In the embodiment shown in Fig. 1, the longitudinal section of the venturi microporous tube is two elliptical shapes that are vertically symmetrical.

Further, as shown in FIG. 1, the axis of the intake pipe 2 is constricted to the center of the venturi microporous pipe, such that the venturi microporous pipe is bilaterally symmetric with respect to the axis of the intake pipe 2, and in the intake pipe 1 The gas can be evenly dispersed along the surface of the tube wall of the venturi microporous tube, providing uniformity of distribution of microbubbles in the oil and enhancing gas-liquid mass transfer.

The microporous tube may use a sintered metal powder microporous material, a metal microporous membrane material, a sintered metal fiber microporous material, or other types of metal microporous materials. Since the oil processing is in a high temperature and high pressure operating environment, preferably, the microporous tube is made of sintered metal powder.

The invention adopts a combination method of microbubble formation, combines chemical and physical methods, and injects a surface active substance into the oil in the first stage to facilitate formation of microbubbles, and at the same time, the microbubbles form a post phase. Stable and difficult to aggregate; the second stage microbubble generator uses microporous medium multi-point contact and venturi effect to refine the bubbles, and the mixing effect is good. At the venturi, the gas-liquid two phases realize gas-liquid mixing at numerous micropores, and the Venturi effect of the distribution tube accelerates the detachment of the microbubbles, and at the same time has a strong suction effect on the gas, strengthens the gas-liquid mixing, and forms a stable Gas-liquid mixture flow.

The working principle of the invention is as follows: the surface active material is uniformly mixed with the oil through the active material filling pipe 4, and the gas phase stream enters the intake space 31 composed of the main pipe 1 and the venturi microporous pipe through the intake pipe 2, in Venturi. The inner surface of the microporous tube is in contact with the liquid phase stream in the main body tube 1, and the gas phase stream enters the liquid stream in the form of micron-sized bubbles, and the venturi microporous tube is used to realize the multi-point contact of the gas-liquid stream on the one hand. On the other hand, it acts as a pressure change to accelerate gas-liquid mixing; due to the action of surface active substances, the bubble formation speed is fast, the bubbles are broken into smaller bubbles, and the accelerated gas is dissolved in the liquid to form a stable gas-liquid mixture flow. The gas-solids mass transfer efficiency of the hydrogenation process is improved by the flow of the mixture through the microbubble generator and then entering the appropriate position of the hydrogenation reactor.

The device for enhancing the gas-liquid mass transfer of the bubbling bed hydrogenation reactor in the present embodiment is a combination of a filler tube 4 and a microbubble generator, and after the action of the surface active substance, hydrogen, oil and surface active substances After passing through the microbubble generator, the gas is dispersed into microbubbles with small size and wide distribution, and the microbubble flow is stable and uniform; the hydrogen in the hydrogenation process can be stably diffused in the liquid flow in the form of microbubbles, and sufficient depth is obtained. Mixing, quickly dissolving into the liquid stream, and forming a micron-sized bubble flow by the suction of the venturi tube, so that it is not necessary to excessively reduce the pore size of the micropore, and the pressure drop of the bubble generator is greatly reduced, which is significant for system energy saving.

The invention adopts the microbubble technology to generate microbubbles in a large amount and efficiently by the structural design of the dispersing gas method and the dissolved gas degassing method, and at the same time inject a surface active substance before the oil enters the microbubble generator, so that the hydrogen gas is in the oil. A relatively stable microbubble flow is formed in the product, and the microbubble flow enters the reaction. Improve the gas-liquid mass transfer efficiency after the inside of the device. The invention can stably generate a continuous microbubble flow by using a combination of a gas-liquid multi-point contact and a venturi effect by means of a surface active material and a porous medium, thereby reducing the pressure drop of the bubble generator, improving the operational flexibility and system stability, Therefore, the gas-liquid mixing effect is improved, and the super-saturated state of the gas in the liquid is achieved. The gas-liquid mixed uniform microbubble flow is introduced into the hydrogenation reactor through the pipeline to participate in the hydrogenation reaction. Since the microbubble flow is relatively uniform, it can be considered to be homogeneous, which greatly weakens the influence of the internal components of the reactor on the logistics and improves the flow. The reaction efficiency enhances the mass transfer between gas and liquid.

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

An apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor, comprising: a main body tube and a filling tube communicating with the main body tube, wherein the main body tube contains oil, the adding The injection tube is used to fill the oil in the main body tube with a surfactant.
The apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor according to claim 1, wherein the filling tube comprises a surface active material filling tube and a surface active material dispersing tube which are in communication with each other. The surface active material dispersing tube is located in the main body tube, and the surface active material dispersing tube is provided with a plurality of distributed pores, and the surface active material dispersing tube is used for dispersing the surface active material in the oil.
The apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor according to claim 2, wherein the surface active material dispersing tube is annular, and the circumferential direction of the surface active material dispersing tube The length direction of the main body tube is vertically arranged.
The apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor according to claim 1, further comprising a microbubble generator comprising a microporous tube and an intake tube, The microporous tube is located in the main body tube and communicates with the main body tube, and the intake tube is in communication with the microporous tube.
The apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor according to claim 4, wherein both ends of the microporous tube are respectively connected to the inner wall of the main body tube.
The apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor according to claim 4, wherein the first end of the intake pipe is located outside the main pipe, and the second of the intake pipe The end is connected to the outer wall of the main body tube, and an air inlet space is formed between the second end of the intake pipe and the microporous tube.
The apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor according to any one of claims 4-6, wherein the microporous tube is a venturi microporous tube.
The apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor according to claim 7, wherein the longitudinal section of the venturi microporous tube is two symmetric about the axis of the main body tube. Oval or two trapezoids.
The apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor according to claim 7, wherein the axis of the intake pipe is constricted to the center of the venturi microporous tube.
The apparatus for enhancing gas-liquid mass transfer in a bubbling bed hydrogenation reactor according to any one of claims 4 to 6, wherein the microporous tube is made of sintered metal powder.