JPH10192690A - Slurry bed reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent the non-uniform distribution of a catalyst within a catalyst slurry bed and to wholly utilize the internal space of a reactor in reaction. SOLUTION: A slurry bed reactor 13 contains a slurry like reaction bed 18 wherein a powder catalyst is suspended in a medium oil and an air layer 14 and has a raw material gas sending-in port provided to the lower part thereof and a product discharge port provided to the upper part thereof and contains a slurry taking-out port 21 provided to the upper part thereof, a slurry insertion port 23 provided to the lower part thereof below the taking-out port 21 and an outside liquid sending pipe 22 connecting the taking-out port 21 to the insertion port 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a slurry bed reactor in which a powder catalyst is suspended in a medium oil. The reactor according to the present invention can be suitably used particularly for the synthesis of dimethyl ether using carbon monoxide gas and hydrogen gas as main raw materials.

[0002]

2. Description of the Related Art Dimethyl ether (CH ₃ OCH) is synthesized from a synthesis gas containing carbon monoxide gas and hydrogen gas as main raw materials.
_{When 3} ) is synthesized, the following reactions proceed.

[0003]

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As a technique for directly synthesizing dimethyl ether from a synthesis gas or the like using carbon monoxide and hydrogen as main raw materials by utilizing the above-mentioned reaction, a technique has been developed in which a raw gas is passed through a fixed-bed catalyst layer and reacted. (Japanese Patent Laid-Open No. 2-2
80836, JP-A-3-8446 and the like.

However, as is apparent from the above reaction formula,
Since the dimethyl ether synthesis reaction is a strongly exothermic reaction as a whole, it is difficult to control the temperature of the catalyst layer in the fixed bed reactor, and deactivation of the catalyst occurs due to local heating of the catalyst layer. In order to avoid this, a technique has been developed in which raw material gas is passed through a reactor filled with a slurry in which catalyst fine particles are suspended in a high-boiling medium oil to synthesize dimethyl ether in high yield ( JP-A-2-9833,
JP-A-3-52835, JP-A-3-181453
Gazette, JP-A-4-264046 or JP-T-Hei-5
8100069). These slurry bed reactors have higher internal temperature uniformity and relatively easier temperature control as compared to fixed bed reactors.

An example of such a known slurry bed reactor is shown in FIG. The main body 13 of the slurry bed reactor is generally cylindrical, and is filled with a catalyst slurry 18, and a gas layer 14 exists above the slurry liquid level 12. The catalyst slurry layer 18 is generally provided with a heat transfer tube 17 for removing reaction heat. Reactor body 1
A raw material gas line 2 is connected to the bottom of 3, and a reaction product gas line 3 is connected to the top. In the synthesis reaction using this slurry bed reactor, the generation of heat spots inside the reactor is suppressed by performing the synthesis reaction in a catalyst slurry layer in which catalyst fine particles are suspended in a high-boiling medium oil. Rate can be achieved.

When dimethyl ether is synthesized by this type of slurry bed reactor, a raw material gas such as a synthesis gas containing carbon monoxide gas and hydrogen gas as main raw materials is pumped from the lower part of the reactor to the reactor. The reaction proceeds while the catalyst slurry layer is being lifted, and the reaction product flows out of the piping at the top of the reactor. That is, the interior of the reactor is filled with a slurry of a three-phase mixture of a high-boiling medium oil, a powder catalyst, and a raw material gas, and a material flowing into the reactor and a material flowing out of the reactor are each a raw material gas. And reaction product gas. Since the dimethyl ether synthesis reaction is a strongly exothermic reaction, a heat transfer tube or the like is provided in the catalyst slurry layer of the reactor, and the generated heat of reaction is removed by a heat medium or the like flowing in the heat transfer tube.

However, this type of slurry bed reactor also has a problem that the catalyst concentration distribution in the catalyst slurry layer becomes non-uniform. That is, the catalyst slurry layer is
Although the catalyst fine particles are suspended in the high-boiling medium oil, the catalyst fine particles gradually settle down in the medium oil to generate a concentration gradient in the vertical direction, and the catalyst fine particles accumulate at the bottom of the slurry bed reactor. . Highly concentrated catalyst accumulated in the lower part of the reactor makes it difficult to participate in the reaction sufficiently efficiently,
The low concentration catalyst at the top of the reactor is consumed in a relatively short time.

In addition, for example, in a method for synthesizing dimethyl ether, two kinds of catalysts are inserted into one slurry bed reactor to carry out the reaction. Therefore, due to the difference in physical properties such as particle size and specific gravity of the two kinds of catalysts, Also with these catalysts, there is a problem that the catalyst is unevenly distributed in the vertical direction in the slurry bed reactor, resulting in a decrease in the reaction conversion and the dimethyl ether reaction selectivity. Conventionally, in order to prevent such uneven distribution of the catalyst, a partition plate 15 (for example, a draft tube) is provided inside the slurry bed reactor as shown in FIG.
The catalyst slurry is made to flow convectively inside the reactor (FIG. 1).
Various techniques have been developed (see Japanese Unexamined Patent Publication (Kokai) 52).
-54078 or JP-A-2-42971).

[0010]

However, it is difficult to control the amount of liquid flowing convectively with the above-mentioned partition plate such as a draft tube.
Frequently, the reaction product may return too much to the lower part of the reactor, causing a problem of lowering the reaction conversion. Further, in the convective flow, it is difficult to move the catalyst accumulated in the lower part of the reactor to the upper part, and the catalyst sometimes remains as accumulated in the lower part of the reactor. Further, when a partition plate such as a draft tube is provided inside the reactor, a space for convective flow is required, so that there is a disadvantage that a space inside the reactor that can be used for the reaction is narrowed.

Accordingly, an object of the present invention is to provide a catalyst reactor using a slurry bed, which can effectively prevent uneven distribution of the catalyst in the catalyst slurry layer and can utilize the entire internal space of the reactor for the reaction. It is to provide a slurry bed reactor.

[0012]

According to the present invention, a slurry-like reaction layer in which a powdery catalyst is suspended in a medium oil and an upper gas layer are provided inside the reactor. A slurry bed reactor provided with a raw material gas inlet and a product outlet at the upper part of the reactor, a slurry outlet provided at the upper part of the reactor; a slurry inlet provided at a lower part of the reactor than the slurry outlet; And a slurry bed reactor (hereinafter sometimes referred to as a slurry reflux type reactor), comprising: an external liquid feed pipe communicating the slurry outlet and the slurry inlet. it can. Further, according to the present invention, there is provided a slurry-like reaction layer in which a powder catalyst is suspended in a medium oil and an upper gas layer therein, and a raw material gas inlet and a reactor at a lower part of the reactor. In a slurry bed reactor having a product outlet at the top, a slurry outlet provided at the upper part of the reactor; a slurry inlet provided at a raw material gas supply pipe connected to the raw material gas inlet; And an external liquid feed pipe communicating with the slurry insertion port; and returning the slurry extracted from the slurry outlet to the slurry reaction layer inside the reactor via the external liquid feed pipe and the raw material gas supply pipe. A slurry bed reactor (hereinafter, may be referred to as a raw material gas-mixed reactor) characterized by including a liquid sending means capable of supplying the raw material gas. Further, the present invention also relates to each of the slurry bed reactors provided with a gas-liquid separation means in the middle of an external liquid feed pipe of the above-mentioned slurry reflux type reactor or raw material gas mixing type reactor. In the present specification, when it is not necessary to distinguish the above-mentioned slurry reflux type reactor and the raw material gas mixing type reactor, they are collectively referred to simply as a slurry bed reactor or a reactor.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The reactor according to the present invention is a slurry bed reactor (particularly a slurry bed reactor for dimethyl ether synthesis), and contains therein a slurry-like reaction layer and a gas phase. In the slurry-like reaction layer, catalyst fine particles were suspended in a medium oil, particularly a high-boiling medium oil [for example, a high-boiling edible oil, a deep-desulfurized light oil, a Fischer-Tropsch synthetic oil (FT oil) or n-cetane]. A catalyst slurry layer,
The reactor is filled from the bottom to the top, above which a gas phase is present. The reactor of the present invention further comprises means for sending a low concentration catalyst-containing slurry present above the catalyst slurry layer in a controlled amount to a lower portion of the catalyst slurry layer.

The slurry reflux type reactor as the first apparatus according to the present invention comprises: (1) a slurry outlet provided at the upper part of the reactor; (2) a slurry inlet provided at a lower part of the reactor than the slurry outlet. And (3) an external liquid feed pipe communicating between the slurry outlet and the slurry insertion port; and in some cases, (4) withdrawing the slurry from the slurry outlet and passing the slurry through the external liquid feed pipe. Means for transferring the slurry to the slurry inlet; and / or (5) controlling the amount of slurry to be withdrawn from the slurry outlet and transferred to the slurry inlet via the external liquid feed pipe. Means that can be used.

FIG. 1 shows an embodiment of the slurry reflux type reactor according to the present invention. 1 are denoted by the same reference numerals when they are the same as those of the conventional slurry bed reactor shown in FIG. In this embodiment, a slurry outlet 21 is provided on the upper side surface of the reactor body 13, and a slurry insertion port 23 is provided on the lower side surface of the reactor body 13, and these are connected by an external liquid feed pipe 22. Further, it is preferable to provide a control means (for example, an adjustment valve) 25 capable of adjusting the amount of slurry in the middle of the external liquid sending pipe 22 because stirring control can be performed. Therefore, in the reactor shown in FIG. 1, the low-concentration catalyst-containing slurry present in the upper portion of the reactor is more preferably transferred from the slurry outlet 21 through the external liquid feed pipe 22 by the effect of convection caused by the rise of bubbles. Can be sent to the slurry inlet 23 at the lower part of the reactor while the flow rate is adjusted by the adjusting valve 25, and the low-concentration catalyst-containing slurry can be sent from the slurry inlet 23 to the catalyst slurry layer 18. Can be made uniform. Also,
Since the slurry circulation system is provided outside the reactor, the inside of the reactor can be effectively used for the reaction.

Further, in the slurry reflux type reactor, gas-liquid separation means (for example, gas-liquid separation means) is provided in the middle of the external liquid feed pipe 22 (preferably, between the slurry outlet 21 and the regulating valve 25). (Separation chamber) 31 can be provided. In the gas-liquid separation chamber 31, a gas layer (product gas) contained in the slurry extracted from the slurry outlet 21.
14a can be separated from catalyst slurry 18b. The product gas 14a thus separated can be combined with the reaction product gas line 3 connected from the upper part of the reactor body 13 by the gas line 26. A regulating valve 32 is provided in the middle of the gas line 26 so that the product gas 1
It is preferable to control the discharge of 4a and adjust the flow rate. Further, the discharge of the product gas 14a and the catalyst slurry 18b is appropriately adjusted by the control valves 25 and 32, so that the external liquid feed pipe 2
2 includes a catalyst slurry 18b excluding the product gas 14a.
Only can send.

In the slurry reflux reactor according to the present invention, the regulating valve 25 may be used instead of the regulating valve 25 or the regulating valve 2.
In addition to the above, a liquid sending means, for example, a liquid sending pump (not shown) is provided in the middle of the external liquid sending pipe 22 (preferably between the regulating valve 25 or the gas-liquid separation chamber 31 and the slurry insertion port 23). ) Can be provided. The amount of the catalyst slurry circulated by the liquid feed pump 24 can be adjusted.

The raw material gas mixing type reactor as the second apparatus according to the present invention comprises: (1) a slurry outlet provided at the upper part of the reactor; (2) a raw material gas supply pipe connected to the raw material gas inlet. (3) an external liquid feed pipe communicating between the slurry outlet and the slurry inlet; and (4) slurry extracted from the slurry outlet.
A liquid sending means capable of returning to the slurry-like reaction layer inside the reactor via the external liquid sending pipe and the raw material gas supply pipe.

FIG. 2 shows an embodiment of the raw material gas mixing type reactor according to the present invention. 2 are denoted by the same reference numerals when they are similar to the conventional slurry bed reactor shown in FIG. Also in this embodiment, a slurry outlet 21 is provided on the upper side surface of the reactor body 13. However, the slurry insertion port 23 is provided in the middle of the raw material gas supply pipe 2 connected to the bottom of the reactor body 13. And slurry outlet 2
1 and the slurry insertion port 23 are connected by the external liquid feed pipe 22. A liquid feeding unit, for example, a liquid feeding pump 24 is provided in the middle of the external liquid feeding pipe 22. Therefore, in the reactor shown in FIG. 2, the low-concentration catalyst-containing slurry present in the upper part of the reactor is taken out from the slurry outlet 21 to the external liquid feed pipe 22 by the liquid feed pump 24,
While adjusting the flow rate, the slurry is fed to the slurry insertion port 23, the slurry and the raw material gas are mixed there, and the raw material gas is discharged from the raw material gas outlet 19 at the bottom of the reactor in the form of a three-phase (gas / liquid / solid) slurry. Let it squirt.

In the raw material gas mixing type reactor according to the present invention,
As described above, since the raw material gas and the catalyst slurry are jetted from the jet port 19 in the form of a three-phase slurry, the ability to blow up the catalyst slurry layer is high unlike a normal reactor in which only the raw material gas is jetted. Accordingly, the high-concentration catalyst-containing medium oil present at the bottom of the catalyst slurry layer is blown up by the three-phase slurry, and the catalyst concentration gradient can be made uniform. Further, since the slurry circulation system is provided outside the reactor, the inside of the reactor can be effectively used for the reaction. Also in this raw material gas mixing type reactor, a control means (for example, an adjustment valve) capable of adjusting the amount of slurry can be provided in the middle of the external liquid sending pipe 22.

In the above-mentioned raw material gas mixing type reactor,
A gas-liquid separation unit, for example, a gas-liquid separation chamber (not shown) is provided in the middle of the external liquid sending pipe 22 to separate the product gas and the catalyst slurry contained in the slurry extracted from the slurry outlet 21 from the slurry. Then, the separated product gas is combined with the reaction product gas line 3, and only the catalyst slurry excluding the product gas can be sent to the slurry insertion port 23.

In the slurry bed reactor according to the present invention, in particular, in the reactor mixed with a raw material gas, a catalyst slurry replenishing line 36 can be provided in the middle of the external liquid feed pipe 22, as shown in FIG. The catalyst slurry replenishment line 36 allows a new catalyst slurry from the catalyst slurry tank 35 to be inserted into the external liquid feed pipe 22 via the liquid feed pipe 36 by the liquid feed pump 37. Further, as shown in FIG. 2, a branch line 33 and a regulating valve 34 are provided in the middle of the external liquid sending pipe 22, so that the deteriorated catalyst slurry can be extracted.

In the slurry reflux type reactor and the raw material gas mixing type reactor according to the present invention, the position for providing the slurry outlet is not limited as long as the slurry containing the catalyst having a low concentration can be taken out. With respect to the entire height of the catalyst slurry layer inside the reactor, preferably to a height of 1/3 from the slurry level to the bottom of the reactor (a height of 1/3 from the top of the slurry layer), more preferably The height is 1/4 from the slurry level to the bottom of the reactor (1/4 from the top of the slurry layer), and most preferably immediately below the slurry level.

In the slurry reflux type reactor according to the present invention, the position where the slurry insertion port is provided is not limited as long as it is lower than the above-mentioned slurry outlet, but the position relative to the entire height of the reactor main body is not limited. Preferably, the height from the bottom to the top is 1/3 (the height from the bottom of the reactor 1/3), more preferably 1 from the bottom to the top of the reactor body.
Up to a height of ４ (height from the bottom of the reactor to １ ／), most preferably at the bottom.

When the slurry bed reactor of the present invention is used as a dimethyl ether synthesis reactor, the reactor is provided with the above-mentioned slurry outlet, slurry inlet, external liquid feed pipe, control means, liquid feed means and the like. Otherwise, it can have the same structure as a conventionally known slurry bed dimethyl ether synthesis reactor of the same kind. That is, at the outlet side of the reactor, first, a reaction product gas is cooled and a methanol / water separator for condensing and separating methanol and water is separated, and the remaining gas is further cooled to condense dimethyl ether and carbon dioxide, thereby producing monoxide. It is preferable to provide an unreacted gas separator for separating carbon and hydrogen and a CO ₂ separator for separating condensed and separated dimethyl ether and carbon dioxide in this order. The above methanol / water separator and unreacted gas separator may be separated into a condenser and a gas-liquid separator, respectively. It is also possible to use an apparatus for first separating carbon monoxide and hydrogen by condensing or coagulating all of methanol, water, dimethyl ether and carbon dioxide, and then separating dimethyl ether from the condensed coagulated product.

FIG. 4 shows an example of such a dimethyl ether synthesis reactor. The manufacturing apparatus may have become of the reactor R, methanol / water separator S1, the unreacted gas separator S2 and CO ₂ separator S3. The raw material gas line 2 is connected to the bottom of the reactor R.
It can be connected to make-up (fresh) gas line 1 and the unreacted CO and H ₂ recycle gas line 7 to circulate and supply for supplying fresh raw material gas on. The reaction product discharged from the top of the reactor R is conveyed to the methanol / water separator S1 by the reaction product gas line 3. A methanol / water line 4 is connected to a methanol / water outlet of the methanol / water separator S1, and a reaction product gas line 5 is connected to a reaction product outlet. The reaction product gas line 5 is connected to the unreacted gas separator S2. The other end of the recycle gas line 7 is connected to the unreacted gas outlet of the unreacted gas separator S2.
In the middle of the recycle gas line 7, a purge line 10 for extracting a part of the gas is connected. A dimethyl ether / CO ₂ line 6 is connected to the dimethyl ether / CO ₂ outlet of the unreacted gas separator S _2, the other end of the dimethyl ether / CO ₂ line 6 is connected to a CO ₂ separator S 3, and the CO _{2 of} the CO ₂ separator S 3 _The outlet ₂ is connected to a CO ₂ line 8, and the dimethyl ether outlet is connected to a dimethyl ether line 9.

When the reactor of the present invention is used as a dimethyl ether synthesis reactor, a methanol synthesis catalyst and a methanol dehydration catalyst may be mixed and filled as a dimethyl ether synthesis catalyst, and a water gas shift catalyst may be optionally added. .

The medium oil that can be used in the reactor of the present invention is not particularly limited as long as it exhibits a liquid state under the reaction conditions used. For example, in the case of a dimethyl ether synthesis reaction, aliphatic, aromatic and alicyclic hydrocarbons, alcohols, ethers, esters, ketones and halides, and mixtures of these compounds can be used. Further, light oil from which sulfur content has been removed, vacuum gas oil, high-boiling fraction of hydrogenated coal tar, Fischer-Tropsch synthetic oil, high-boiling edible oil and the like can also be used. The amount of the catalyst to be present in the medium oil can be appropriately determined depending on the type of the medium oil, reaction conditions, and the like, but is usually 1 to 50% by weight based on the medium oil.
About 10 to 30% by weight is preferable.

The reaction conditions that can be used in the reactor of the present invention are not particularly limited, but in the case of a dimethyl ether synthesis reaction, the reaction temperature is preferably one.
It is 50 to 400 ° C, more preferably 250 to 350 ° C. If the reaction temperature is lower than 150 ° C. or higher than 400 ° C., the conversion of carbon monoxide may decrease. The reaction pressure is preferably 10 to 100 kg / cm ² , more preferably 15 to 80 kg / cm ² , and particularly preferably 20 to 80 kg / cm ² .
７０70 kg / cm ² . Reaction pressure is 10kg / cm
^If it is lower than ^2, the conversion of carbon monoxide may be low, and if it is higher than 100 kg / cm ² , the reactor becomes special, and a large amount of energy is required for pressurization, which is not economical. The space velocity (the supply rate of the mixed gas in a standard state per kg of the catalyst) is preferably 100 to 50,000 l / kg · h, more preferably 50 to 10000 l / kg · h.
0 to 30000 l / kg · h. Space velocity is 500
If it is larger than 00 l / kg · h, the conversion rate of carbon monoxide may be low, and if it is smaller than 100 l / kg · h, the reactor becomes extremely large and may not be economical.

[0030]

According to the present invention, it is possible to provide a slurry bed reactor which can effectively prevent uneven distribution of the catalyst in the catalyst slurry layer and can utilize all the internal space of the reactor for the reaction. .

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the structure of a reactor according to one embodiment of the present invention.

FIG. 2 is an explanatory view showing the structure of a reactor according to another embodiment of the present invention.

FIG. 3 is an explanatory view showing the structure of an example of a conventional reactor.

FIG. 4 is a flow sheet of an example of a dimethyl ether production apparatus into which the reactor of the present invention is incorporated.

[Explanation of symbols]

1. Makeup (fresh) gas line; 2.
..Raw gas line; 3... Reaction product gas line;
4: methanol / water line; 5: reaction product gas line; 6: dimethyl ether / CO ₂ line;
7: Recycle gas line; 8: CO ₂ line; 9: Dimethyl ether line; 10: Purge line; 12: Slurry level; 13: Reactor main body: 14, 14a ..Gas layer; 15 draft tube; 17 heat transfer tube; 18 slurry-like reaction layer; 18a catalyst slurry; Outlet: 22 External liquid feed pipe; 23 Slurry insertion port; 24 Liquid feed pump; 25, 32, 34 Adjustment valve; 26 Gas line; Liquid separation chamber; 33: catalyst slurry extraction line; 35: catalyst slurry tank;
..Catalyst slurry replenishment line;
R: Reactor; S1: Methanol / water stricter; S
2: Unreacted gas separator; S3: CO ₂ separator

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C07B 61/00 300 C07B 61/00 300 (72) Inventor Masami Ono 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan Inside Steel Pipe Co., Ltd.

Claims (3)

[Claims] 1. A reactor in which a slurry-like reaction layer in which a powder catalyst is suspended in a medium oil and an upper gas layer are included in a reactor, and a raw material gas inlet is provided in a lower part of the reactor and a product outlet is provided in an upper part of the reactor. A slurry outlet provided at the upper part of the reactor; a slurry inlet provided at a lower part of the reactor than the slurry outlet; and the slurry outlet and the slurry inlet A slurry bed reactor comprising: 2. A reactor in which a slurry-like reaction layer in which a powder catalyst is suspended in a medium oil and an upper gas layer are included in a reactor, and a raw material gas inlet is provided in a lower part of the reactor and a product outlet is provided in an upper part of the reactor. A slurry outlet provided at the upper part of the reactor; a slurry inlet provided in a source gas supply pipe connected to the source gas inlet; and a slurry outlet and the slurry inlet And a liquid sending means capable of returning the slurry extracted from the slurry outlet to the slurry-like reaction layer inside the reactor via the external liquid sending pipe and the raw material gas supply pipe. A slurry bed reactor comprising: 3. The slurry bed reactor according to claim 1, wherein a gas-liquid separation means is provided in the middle of the external liquid sending pipe.