JP2686276B2 - Three-phase flow reaction method and apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a three-phase flow reaction method for gas, liquid and solid, and an apparatus thereof for efficiently separating gas and liquid.

[Conventional technology]

A gas, liquid, and solid three-phase flow reactor produces a large amount of heat of reaction using a reactor, especially a catalyst, because the three-phase contact efficiency is good and the mixing inside the reactor is good. It is known to be effective for exothermic reaction systems. Examples thereof include a hydrodesulfurization reactor, a hydrocracking reactor, and the like, in which heavy and medium fractions fractionated from crude oil are fed in the presence of a catalyst while supplying hydrogen gas. In addition, as another example, a mixed gas containing carbon monoxide and hydrogen as main components is supplied into a mixture of a solvent and a melting medium,
There is a synthetic reaction device for synthesizing methyl alcohol.

The general flow state of a three-phase flow reactor is as described in detail in Eiichi Tanaka, Vol. 34, No. 12, p. 1265 (1970), Chemical Engineering, etc. / 2 to 2/3
A fluidized bed of solid particles, which is sufficient to flow solid particles such as a catalyst filled to a certain degree, and which causes liquid and gas to flow upward from the lower part of the container at a speed at which solid particles are not entrained and rise. Is formed. In order to realize this fluidized state, the liquid is extracted from the upper part of the expanded catalyst layer and circulated through the liquid supplied to the lower part of the cylindrical container using a pump, which is the liquid necessary for fluidizing the catalyst. It is an indispensable means for maintaining the flow velocity by circulating the liquid.

Further, specific examples using this three-phase flow reactor, petroleum-based heavy, in the case of hydrodesulfurization of the middle distillate 100-150 kg / cm ² G, under the conditions of 350-400 ℃ 0.5-2 mm
It is carried out by bringing a φ-cylindrical or spherical nickel-molybdenum-based catalyst into contact with the feed oil and gaseous hydrogen.

The structure of a conventional typical three-phase flow reactor will be described with reference to FIG.

The inside of the reactor main body 1 is filled with a catalyst, and the upper surface 2 of this catalyst layer is fluidized by the upward flow of liquid and gas and expands to the upper surface 3 of the expanded catalyst layer. A dispersion plate 4 such as a perforated plate is provided in the lower part of the catalyst layer, and gas supplied from the lower part,
The liquid is well dispersed and the catalyst is prevented from falling to the bottom of the container and accumulating. The supply gas 5 and the supply liquid 6 are supplied together with or separately from the circulating liquid 7 from the lower part of the reactor main body 1, pass through the dispersion plate 4, and react while rising the catalyst layer. After passing through the catalyst layer, the gas and the liquid pass through the clarification layer 8 for separating the catalyst, and the reaction gas 9 passes through the reactor body 1
Is extracted to the outside of. A part of the reaction liquid is discharged as a reaction product liquid 12 to the outside of the system, but most of the reaction liquid is a circulating liquid 7, and a suction pipe inlet 10 and a suction pipe 11 are provided by a pump 13 placed inside or outside the reactor main body 1. It is circulated to the reactor main body 1 via.

[Problems to be solved by the invention]

The above is a typical three-phase flow reactor according to the conventional method. In the case of such a structure, unreacted gas among the supplied gases flows out from the expansion catalyst layer upper surface 3 together with the liquid, and the clarification layer is used. No. 8 was raised, and it was flowing into the inlet 10 of the suction pipe without being sufficiently separated into gas and liquid. Therefore, there is a problem that the discharge performance of the pump 13 is extremely lowered.

The present invention is intended to provide a three-phase flow reaction method and apparatus in which the above-mentioned problems of the prior art are solved.

[Means for Solving the Problems] The present invention provides (1) a gas and a liquid are supplied to a solid particle layer from the bottom of the bed through a disperser to form a three-phase fluidized bed, and the liquid is passed through the fluidized bed to form a solid phase bed. In a three-phase fluidized bed reaction method of extracting from a suction pipe provided vertically through the center and circulating it again in the apparatus, cone-shaped bubbles provided on the outer periphery of a cylindrical suction part below the inlet of the suction pipe. A three-phase flow reaction method characterized in that a bubble is temporarily retained in a coalescing vessel to grow its diameter to increase the buoyancy of the bubble and to prevent the gas from being entrained in the liquid and sucked into the suction part. And (2) a suction pipe provided with gas and liquid from the bottom of the bed through a disperser to form a three-phase fluidized bed, and the liquid passes through the fluidized bed and vertically passes through the center of the bed. In the three-phase fluidized bed reactor of the type in which it is further extracted and circulated again in the apparatus, the suction The pipe inlet part has a reverse conical connection part, a cylindrical suction part provided on the upper part of the connection part, and a plurality of conical bubble coalescing devices are formed on the outer circumference of the suction pipe immediately below the connection part of the suction pipe. It is a three-phase flow reactor.

(Operation)

In the method and apparatus of the present invention, when the gas rising together with the liquid passes under the inlet of the suction pipe, it collides with a conical bubble coalescing device provided on the outer circumference of the suction pipe. At this time, since the bubble coalescing device has a conical shape and has a space inside, the gas is likely to stay. The accumulated gas becomes a large bubble, overflows from the circumference of the lower surface, and rises on the outer circumference of the inverted conical portion and the tubular portion of the suction pipe inlet.

At this time, since the liquid is sucked into the suction pipe, there is also a liquid flow directed downward from the upper end of the suction pipe, but since the bubble diameter of the gas is large, the buoyancy is large, and therefore the gas rises without being entrained in the liquid flow. Therefore, gas-liquid separation is easily performed.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is an enlarged view of the vicinity of the inlet of the liquid suction section according to this embodiment, and FIG. 2 is a sectional view taken along the line AA of FIG.

This example has the same structure as the conventional three-phase flow reactor shown in FIG. 5 except for the points described below.
In this embodiment, an inverted conical connection part 19 is provided on the upper part of the suction pipe 11, and a cylindrical suction part 16 extending upward from the upper end of the connection part 19 is provided to form the suction pipe inlet part 10. ing. A support rod is provided on the outer circumference of the suction pipe 11 just below the suction pipe inlet 10.
A plurality of conical bubble coalescers 17 fixed by 18 are provided vertically and circumferentially.

As shown in FIG. 2, the bubble coalescing device 17 is installed in almost the entire area in the circumferential direction in the reactor by changing the length of the support rod 18 and the attachment position to the suction pipe 11.

In this embodiment, during steady operation of the three-phase flow reactor, the catalyst layer 14 expands by several tens of percent. The liquid flowing out from the catalyst layer 14 rises in the clarification layer 8, is sucked through the suction pipe inlet 10, and is discharged through the suction pipe 11. The gas rises as bubbles. Since the gas entrained in the liquid is in a bubble state,
Due to its own buoyancy, it rises faster than the rising speed of the liquid.

The gas accompanies the liquid, rises in the fining layer 8, and collides with the bubble coalescing device 17 fixed to the outer circumference of the suction pipe 11 by the support rod 18. The bubble coalescing device 17 has a conical shape like a camp, the central portion of the upper end is closed to form a space portion 20, and a part of gas and liquid stay in the space portion 20. The accumulated gas is space 20
When it becomes full, it overflows from the bubble coalescing device 17, becomes a large bubble 21 and rises outside the cylindrical suction portion 16 and rises from the upper end of the suction pipe inlet portion 10. Since the bubble 21 has a larger diameter than the bubble in the liquid and accordingly has a large buoyancy, it is rarely entrained in the liquid sucked by the suction portion 16 and goes to the reactor outlet 22 provided above the reactor body 1. . Therefore, the effect of separating the gas and the liquid is large, and the gas is less entrained in the suction liquid.

An example of examining the above effects by using a cold model is shown below.

As shown in FIG. 3, the amount of gas contained in the circulating liquid 7 was compared using a cold model device made of transparent plastic. The inner diameter of the reactor body 1 of the used apparatus is 1000 mm,
The height is 6000 mm. A bubble cap was used as the disperser 4. The suction pipe 11 has an inner diameter of 230 mm, the suction pipe inlet portion 10 and the bubble coalescer 17 provided immediately below the suction pipe 11 have the same structure as the above embodiment, and the inner diameter of the suction pipe inlet portion upper portion is 700 mm,
The bubble coalescing device 17 has an inner diameter of 150 mm on the bottom surface and a height of 100 mm, and is provided with eight bubbles.

As the catalyst particles, an extruded product having a diameter of 1.2 mm and a length of about 2 mm was used. Air was used as the gas, and an aqueous solution containing 20% by weight of ethanol was used as the liquid.

In order to confirm the gas-liquid separation performance of the inlet 10 of the suction pipe, the circulating liquid 7 was circulated by the pump 13 and the relationship between the amount of gas in the circulating liquid 7 and the superficial velocity of the supply gas 5 was obtained. At this time, the liquid flow rate is about 5 cm /
s.

FIG. 4 shows the results obtained with the suction pipe inlet structure according to the prior art shown in FIG. 5 and the structure according to the above-described embodiment.

As is clear from FIG. 4, in the conventional example b, the operation area of the pump was about 1.5 cm / s or less in the gas superficial velocity, but in Example a of the present invention, it was about 4.5 cm / s or more, It turned out that the operating range of the pump had expanded.

The desirable structure of the suction pipe inlet portion 10 of the three-phase flow reactor according to the present invention is that the bubble coalescing device 17 provided immediately below the suction pipe connecting portion 19 having an inverted conical shape is vertically and circumferentially alternately arranged in FIG. 1 and FIG. Second
As shown in the figure, a plurality of them are arranged so that the gas on the entire surface of the reactor is allowed to collide with each other as much as possible.

In the above embodiment, the bubble coalescing device having a conical shape and the same diameter is used, but it is also possible to use a different diameter, a pyramid shape, a cylindrical shape or the like.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, the three-phase flow reaction method and the device according to the present invention efficiently separate gas and liquid at the liquid suction pipe inlet in the device and suppress the amount of gas contained in the suction liquid. Therefore, the operation range of the pump can be expanded to realize stable operation.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is an explanation of a cold model device for grasping the performance of the present invention. Fig. 4 is a diagram showing the relationship between the gas superficial velocity, the porosity, and the pump inoperable region by the experiment using the cold model device shown in Fig. 3, and Fig. 5 is the conventional three-phase flow reactor. FIG. In the figure, 1 ... Reactor body, 2 ... Top of catalyst layer at rest, 3 ... Expansion catalyst layer top surface, 4 ... Dispersion plate, 5 ... Supply gas, 6 ... Supply liquid, 7 ... Circulating liquid , 8 …… Kiyosumi layer, 9
...... Reaction gas, 10 …… Suction tube inlet, 11 …… Suction tube, 12
...... Reaction product liquid, 13 ...... Pump, 14 ...... Catalyst layer, 15 ......
Bubbles, 16 …… Suction tube suction part, 17 …… Bubble coalescing device, 18 ……
Support rod, 19 ... Suction tube connection, 20 ... Space, 21 ... Large bubbles, 22 ... Reactor outlet.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumihiro Kono 4-15-5 Kamisueyoshi, Tsurumi-ku, Yokohama-shi, Kanagawa (72) Inventor Toshihiko Masuda 1-1-14-8, Kyowa, Sagamihara-shi, Kanagawa (56) References Special Kai 64-38136 (JP, A)

Claims (2)

(57) [Claims] 1. A suction system in which a gas and a liquid are supplied to the solid particle layer from the bottom of the layer through a disperser to form a three-phase fluidized bed, and the liquid is passed through the fluidized bed and vertically penetrates through the center of the bed. In the three-phase fluidized bed reaction in which it is withdrawn from the tube and circulated again in the device,
In the cone-shaped bubble coalescing device provided on the outer periphery of the cylindrical suction portion below the inlet of the suction pipe, the bubbles are temporarily retained and their diameter is grown to increase the buoyancy of the bubbles. A three-phase flow reaction method, characterized in that it is prevented from being sucked along with a liquid. 2. A suction provided by supplying gas and liquid to the solid particle layer from the bottom of the layer through a disperser to form a three-phase fluidized bed, and passing the liquid through the fluidized bed and vertically penetrating through the center of the bed. In a three-phase fluidized bed reactor of the type in which the suction pipe is withdrawn from the pipe and circulated again in the device, the suction pipe inlet part is a reverse cone-shaped connection part and a cylindrical suction part provided above the connection part and the suction part. A three-phase flow reactor in which a plurality of cone-shaped bubble coalescing devices are formed on the outer circumference of a suction pipe immediately below a pipe connecting portion.