JP2019178100A - Mtbe production equipment, isobutylene production equipment, mtbe production process, and isobutylene production process - Google Patents

Abstract

To properly handle purge stream generated when the inside of an MTBE synthesis reactor is opened to the atmosphere.SOLUTION: MTBE production equipment 300 comprises: an MTBE synthesis reactor 5; an MTBE distillation tower 10; a first extractor 60; a methanol distillation tower 50, and at least one of the following lines (A) and (B). A line (A (A1b, A2)) connecting the MTBE synthesis reactor 5 and the methanol distillation tower 50 to each other without passing through the MTBE distillation tower 10 and the first extractor 60. A line (B) connecting the MTBE synthesis reactor 5 and the first extractor 60 to each other without passing through the MTBE distillation tower 10.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an MTBE and isobutylene production apparatus and production method.

An MTBE synthesis step in which isobutylene in a hydrocarbon mixture containing isobutylene is reacted with methanol in the presence of a catalyst to obtain a reaction mixture containing methyl-tert-butyl ether (hereinafter referred to as “MTBE”), and the reaction mixture Patent Document 1 discloses a method having an MTBE separation step of separating MTBE from the mixture by distillation.
Further, Patent Document 2 discloses a method of decomposing MTBE and purifying it by distillation or the like to obtain isobutylene.

Japanese Patent Publication No.55-27159 JP 2007-269708 A

  The activity of the catalyst used in the MTBE synthesis process gradually decreases. Therefore, when the catalyst activity decreases, it is necessary to stop the MTBE synthesis reaction, and then open the MTBE synthesis reactor to the atmosphere and replace the internal catalyst.

  After the MTBE synthesis reaction is stopped, C4 hydrocarbons such as isobutylene, MTBE, and methanol remain in the catalyst of the MTBE synthesis reactor. Since these compounds are flammable, it is preferable to remove these compounds from the catalyst of the MTBE synthesis reactor before release to the atmosphere. Therefore, it is conceivable that a solvent such as methanol or water is supplied into the MTBE synthesis reactor to elute the compound in the catalyst into the solvent.

  However, the composition of the purge flow (comprising the solvent as a main component) from which the compound in the catalyst is eluted differs greatly from the flow (mainly containing MTBE) that is supplied to the distillation column that performs the MTBE separation step during normal operation. Therefore, if it is used as it is in the distillation column, the composition of the stream supplied from the distillation column to the subsequent process is greatly changed, which adversely affects the subsequent process.

  The present invention has been made in view of the above problems, and an apparatus for producing MTBE and isobutylene capable of appropriately treating a purge flow generated when the inside of an MTBE synthesis reactor is opened to the atmosphere, and the use thereof It is an object of the present invention to provide a method for producing MTBE and isobutylene.

An MTBE manufacturing apparatus according to the present invention includes:
An MTBE synthesis reactor having an inlet to which an MTBE raw material containing methanol is supplied and an outlet for discharging a reaction product;
An MTBE distillation column having an inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet;
An inlet connected to the top outlet of the MTBE distillation column; a water inlet to which water is supplied; an aqueous phase outlet for discharging an aqueous phase containing methanol; and an oil phase outlet for discharging an oil phase. A first extractor,
A methanol distillation column having an inlet connected to the aqueous phase outlet of the first extractor, a tower top outlet, and a tower bottom outlet; and
At least one of the following lines (A) and (B) is provided.
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column and the first extractor.
Line (B) for connecting the MTBE synthesis reactor and the first extractor without passing through the MTBE distillation column

Here, the MTBE synthesis reactor has a plurality of unit reactors connected in series,
The line (A) connects the line between the unit reactors and the methanol distillation column,
The line (B) can connect the line between the unit reactors and the first extractor.

The apparatus further includes a tank connected to the top outlet of the methanol distillation column, and a reflux line connecting the tank and the methanol distillation column.
The line (A) can connect the MTBE synthesis reactor and the methanol distillation column via the tank and the reflux line.

More specifically, the MTBE manufacturing apparatus according to the present invention includes:
An MTBE synthesis reactor in which isobutylene in a hydrocarbon mixture containing isobutylene is reacted with methanol to obtain a stream (F0) containing MTBE, the hydrocarbon mixture and methanol,
An MTBE distillation column that distills the stream (F0) to produce a stream (F1) mainly comprising MTBE and a stream (F6) mainly comprising a hydrocarbon mixture and comprising methanol;
A first extractor for contacting the stream (F6) with water to produce a stream (F12) mainly comprising a hydrocarbon mixture and a stream (F3) mainly comprising water and comprising methanol;
A methanol distillation column that distills the stream (F3) to produce a stream mainly comprising water (F10) and a stream mainly comprising methanol (F9); and
The MTBE manufacturing apparatus includes at least one of the following lines (A) and (B).
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column and the first extractor.
Line (B) for connecting the MTBE synthesis reactor and the first extractor without passing through the MTBE distillation column
In the present specification, the expression “a stream mainly containing the component α” means that the concentration of the component α is the maximum among the concentrations of the respective components included in the stream.

The first isobutylene production apparatus according to the present invention comprises:
An MTBE synthesis reactor having an inlet to which the MTBE raw material is supplied and an outlet for discharging the reaction product;
An inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet, or an inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet And an MTBE distillation column having a side outlet,
An MTBE decomposition reactor having an inlet connected to the bottom outlet or the side outlet of the MTBE distillation column, and an outlet for discharging an MTBE decomposition product containing isobutylene and methanol;
A cracked product distillation column having an inlet connected to an outlet of the MTBE cracking reactor, a tower top outlet, and a tower bottom outlet;
A methanol distillation tower having an inlet connected to the bottom outlet of the decomposition product distillation tower, a tower top outlet, and a tower bottom outlet; and
At least one of the following lines (A) and (C) is provided.
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column, the MTBE decomposition reactor, and the decomposition product distillation column
Line (C) for connecting the MTBE synthesis reactor and the cracked product distillation column without passing through the MTBE distillation column and the MTBE decomposition reactor

Here, the MTBE synthesis reactor has a plurality of unit reactors connected in series,
The line (A) connects the line between the unit reactors and the methanol distillation column,
The line (C) can connect the line between the unit reactors and the decomposition product distillation column.

More specifically, the first isobutylene production apparatus according to the present invention includes:
An MTBE synthesis reactor in which isobutylene in a hydrocarbon mixture containing isobutylene is reacted with methanol to obtain a stream (F0) containing MTBE, the hydrocarbon mixture and methanol,
An MTBE distillation column that distills the stream (F0) to produce a stream (F1) mainly comprising MTBE and a stream (F6) mainly comprising a hydrocarbon mixture and comprising methanol;
An MTBE cracking reactor that cracks MTBE in the stream (F1) to produce a stream (F2A) comprising methanol and isobutylene;
A cracker distillation column that distills the stream (F2A) to produce a stream (F7) mainly comprising methanol and a stream (F2B) mainly comprising isobutylene;
A methanol distillation column that distills the stream (F7) to produce a stream mainly comprising water (F10) and a stream mainly comprising methanol (F9); and
An isobutylene production apparatus comprising at least one of the following lines (A) and (C):
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column, the MTBE decomposition reactor, and the decomposition product distillation column
Line (C) for connecting the MTBE synthesis reactor and the cracked product distillation column without passing through the MTBE distillation column and the MTBE decomposition reactor

The second isobutylene production apparatus according to the present invention comprises:
An MTBE synthesis reactor having an inlet to which the MTBE raw material is supplied and an outlet for discharging the reaction product;
An inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet, or an inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet And an MTBE distillation column having a side outlet,
An inlet connected to the top outlet of the MTBE distillation column; a water inlet to which water is supplied; an aqueous phase outlet for discharging an aqueous phase containing methanol; and an oil phase outlet for discharging an oil phase. A first extractor,
An MTBE decomposition reactor having an inlet connected to the bottom outlet or the side outlet of the MTBE distillation column, and an outlet for discharging an MTBE decomposition product containing isobutylene and methanol;
A cracked product distillation column having an inlet connected to an outlet of the MTBE cracking reactor, a tower top outlet, and a tower bottom outlet;
A methanol distillation column having an inlet connected to the bottom outlet of the decomposition product distillation column and / or the aqueous phase outlet of the first extractor, a top outlet, and a bottom outlet, and At least one of the lines A) to (C) is provided.
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column, the first extractor, the MTBE decomposition reactor, and the decomposition product distillation column
Line (B) for connecting the MTBE synthesis reactor and the first extractor without passing through the MTBE distillation column
Line (C) for connecting the MTBE synthesis reactor and the cracked product distillation column without passing through the MTBE distillation column and the MTBE decomposition reactor

Here, the MTBE synthesis reactor has a plurality of unit reactors connected in series,
The line (A) connects the line between the unit reactors and the methanol distillation column,
The line (B) connects the line between the unit reactors and the first extractor,
The line (C) connects the line between the unit reactors and the decomposition product distillation column.
be able to.

More specifically, the second isobutylene production apparatus according to the present invention includes:
An MTBE synthesis reactor in which isobutylene in a hydrocarbon mixture containing isobutylene is reacted with methanol to obtain a stream (F0) containing MTBE, the hydrocarbon mixture and methanol,
An MTBE distillation column that distills the stream (F0) to produce a stream (F1) mainly comprising MTBE and a stream (F6) mainly comprising a hydrocarbon mixture and comprising methanol;
A first extractor for contacting the stream (F6) with water to produce a stream (F12) mainly comprising a hydrocarbon mixture and a stream (F3) mainly comprising water and comprising methanol;
An MTBE cracking reactor that cracks MTBE in the stream (F1) to produce a stream (F2A) comprising methanol and isobutylene;
A cracker distillation column that distills the stream (F2A) to produce a stream (F7) mainly comprising methanol and a stream (F2B) mainly comprising isobutylene;
A methanol distillation column that distills the stream (F7) and the stream (F3) to produce a stream mainly comprising water (F10) and a stream mainly comprising methanol (F9); and
An isobutylene production apparatus comprising at least one of the following lines (A) to (C).
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column, the MTBE decomposition reactor, and the decomposition product distillation column
Line (B) for connecting the MTBE synthesis reactor and the first extractor without passing through the MTBE distillation column
Line (C) for connecting the MTBE synthesis reactor and the cracked product distillation column without passing through the MTBE distillation column and the MTBE decomposition reactor

The third isobutylene production apparatus according to the present invention comprises:
An MTBE synthesis reactor having an inlet to which the MTBE raw material is supplied and an outlet for discharging the reaction product;
An inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet, or an inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet And an MTBE distillation column having a side outlet,
An MTBE decomposition reactor having an inlet connected to the bottom outlet or the side outlet of the MTBE distillation column, and an outlet for discharging an MTBE decomposition product containing isobutylene and methanol;
A second inlet having an inlet connected to an outlet of the MTBE decomposition reactor, a water inlet to which water is supplied, an aqueous phase outlet for discharging an aqueous phase containing methanol, and an oil phase outlet for discharging an oil phase; Extractor,
A methanol distillation column having an inlet connected to the aqueous phase outlet of the second extractor, a tower top outlet, and a tower bottom outlet; and
At least one of the following lines (A) and (D) is provided.
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column, the MTBE decomposition reactor, and the second extractor.
Line (D) for connecting the MTBE synthesis reactor and the second extractor without passing through the MTBE distillation column and the MTBE decomposition reactor

Here, the MTBE synthesis reactor has a plurality of unit reactors connected in series,
The line (A) connects the line between the unit reactors and the methanol distillation column,
The line (D) can connect the line between the unit reactors and the second extractor.

More specifically, the third isobutylene production apparatus according to the present invention includes:
An MTBE synthesis reactor in which isobutylene in a hydrocarbon mixture containing isobutylene is reacted with methanol to obtain a stream (F0) containing MTBE, the hydrocarbon mixture and methanol,
An MTBE distillation column that distills the stream (F0) to produce a stream (F1) mainly comprising MTBE and a stream (F6) mainly comprising a hydrocarbon mixture and comprising methanol;
An MTBE cracking reactor that cracks MTBE in the stream (F1) to produce a stream (F2) comprising methanol and isobutylene;
A second extractor for contacting the stream (F2) with water to produce a stream (F5) mainly comprising isobutylene and a stream (F8) mainly comprising water and comprising methanol;
A methanol distillation column that distills the stream (F8) to produce a stream mainly comprising water (F10) and a stream mainly comprising methanol (F9); and
An isobutylene production apparatus comprising at least one of the following lines (A) and (D):
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column, the MTBE decomposition reactor, and the second extractor.
Line (D) for connecting the MTBE synthesis reactor and the second extractor without passing through the MTBE distillation column and the MTBE decomposition reactor

A fourth isobutylene production apparatus according to the present invention comprises:
An MTBE synthesis reactor having an inlet to which the MTBE raw material is supplied and an outlet for discharging the reaction product;
An inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet, or an inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet And an MTBE distillation column having a side outlet,
An inlet connected to the top outlet of the MTBE distillation column; a water inlet to which water is supplied; an aqueous phase outlet for discharging an aqueous phase containing methanol; and an oil phase outlet for discharging an oil phase. A first extractor,
An MTBE decomposition reactor having an inlet connected to the bottom outlet or the side outlet of the MTBE distillation column, and an outlet for discharging an MTBE decomposition product containing isobutylene and methanol;
A second inlet having an inlet connected to an outlet of the MTBE decomposition reactor, a water inlet to which water is supplied, an aqueous phase outlet for discharging an aqueous phase containing methanol, and an oil phase outlet for discharging an oil phase; Extractor,
A methanol distillation column having an inlet connected to the aqueous phase outlet of the first extractor and / or the aqueous phase outlet of the second extractor, a tower top outlet, and a tower bottom outlet; and
An isobutylene production apparatus comprising at least one of the following lines (A), (B), and (D):
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column, the first extractor, the MTBE decomposition reactor, and the second extractor.
Line (B) for connecting the MTBE synthesis reactor and the first extractor without passing through the MTBE distillation column
Line (D) for connecting the MTBE synthesis reactor and the second extractor without passing through the MTBE distillation column and the MTBE decomposition reactor

Here, the MTBE synthesis reactor has a plurality of unit reactors connected in series,
The line (A) connects the line between the unit reactors and the methanol distillation column,
The line (B) connects the line between the unit reactors and the first extractor,
The line (D) can connect the line between the unit reactors and the second extractor.

In addition, each of the above isobutylene production apparatuses further includes a tank connected to the top outlet of the methanol distillation column, and a reflux line connecting the tank and the methanol distillation column.
The line (A) can connect the MTBE synthesis reactor and the methanol distillation column via the tank and the reflux line.

More specifically, the fourth isobutylene production apparatus according to the present invention includes:
An MTBE synthesis reactor in which isobutylene in a hydrocarbon mixture containing isobutylene is reacted with methanol to obtain a stream (F0) containing methyl-tert-butyl ether (MTBE), the hydrocarbon mixture and methanol,
An MTBE distillation column that distills the stream (F0) to produce a stream (F1) mainly comprising MTBE and a stream (F6) mainly comprising a hydrocarbon mixture and comprising methanol;
A first extractor for contacting the stream (F6) with water to produce a stream (F12) mainly comprising a hydrocarbon mixture and a stream (F3) mainly comprising water and comprising methanol;
An MTBE cracking reactor that cracks MTBE in the stream (F1) to produce a stream (F2) comprising methanol and isobutylene;
A second extractor for contacting the stream (F2) with water to produce a stream (F5) mainly containing isobutylene and a stream (F8) mainly containing water and containing methanol;
A methanol distillation column that distills the stream (F3) and the stream (F8) to produce a stream (F10) mainly comprising water and a stream (F9) mainly comprising methanol; and
An isobutylene production apparatus comprising at least one of the following lines (A), (B), and (D).
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column, the MTBE decomposition reactor, and the second extractor.
Line (B) for connecting the MTBE synthesis reactor and the first extractor without passing through the MTBE distillation column
Line (D) for connecting the MTBE synthesis reactor and the second extractor without passing through the MTBE distillation column and the MTBE decomposition reactor

An MTBE manufacturing method according to the present invention is an MTBE manufacturing method using the above-described MTBE manufacturing apparatus,
Supplying the hydrocarbon mixture containing isobutylene and methanol to the MTBE synthesis reactor containing the catalyst to produce MTBE;
Stopping the supply of the hydrocarbon mixture to the MTBE synthesis reactor;
Supplying methanol to the MTBE synthesis reactor after stopping the supply of the hydrocarbon mixture to obtain a purge stream (a) in which the hydrocarbon mixture and MTBE contained in the catalyst are eluted in methanol;
Sending the purge stream (a) to the methanol distillation column via the line (A) or to the first extractor via the line (B);
Further supplying water to the MTBE synthesis reactor to obtain a purge stream (b) in which methanol contained in the catalyst is eluted in water;
Sending the purge stream (b) to the methanol distillation column via the line (A) or to the first extractor via the line (B).

A first isobutylene production method according to the present invention is a method for producing isobutylene using the first isobutylene production apparatus described above.
Supplying the hydrocarbon mixture containing isobutylene and methanol to the MTBE synthesis reactor containing the catalyst to produce isobutylene;
Stopping the supply of the hydrocarbon mixture to the MTBE synthesis reactor;
Supplying methanol to the MTBE synthesis reactor after stopping the supply of the hydrocarbon mixture to obtain a purge stream (a) in which the hydrocarbon mixture and MTBE contained in the catalyst are eluted in methanol;
Sending the purge stream (a) to the methanol distillation column via the line (A) or to the cracked product distillation column via the line (C);
Further supplying water to the MTBE synthesis reactor to obtain a purge stream (b) in which methanol contained in the catalyst is eluted in water;
Sending the purge stream (b) to the methanol distillation column via the line (A) or to the cracked product distillation column via the line (C);
Is provided.

A second method for producing isobutylene according to the present invention is a method for producing isobutylene using the second apparatus for producing isobutylene described above.
Supplying the hydrocarbon mixture containing isobutylene and methanol to the MTBE synthesis reactor containing the catalyst to produce isobutylene;
Stopping the supply of the hydrocarbon mixture to the MTBE synthesis reactor;
Supplying methanol to the MTBE synthesis reactor after stopping the supply of the hydrocarbon mixture to obtain a purge stream (a) in which the hydrocarbon mixture and MTBE contained in the catalyst are eluted in methanol;
The purge stream (a) is sent to the methanol distillation column via the line (A), sent to the first extractor via the line (B), or the line via the line (C). Sending to the decomposition product distillation tower;
Further supplying water to the MTBE synthesis reactor to obtain a purge stream (b) in which methanol contained in the catalyst is eluted in water;
The purge stream (b) is sent to the methanol distillation column via the line (A), sent to the first extractor via the line (B), or the line via the line (C). And a step of sending it to a decomposition product distillation column.

A third method for producing isobutylene according to the present invention is a method for producing isobutylene using the third apparatus for producing isobutylene described above.
Supplying the hydrocarbon mixture containing isobutylene and methanol to the MTBE synthesis reactor containing the catalyst to produce isobutylene;
Stopping the supply of the hydrocarbon mixture to the MTBE synthesis reactor;
Supplying methanol to the MTBE synthesis reactor after stopping the supply of the hydrocarbon mixture to obtain a purge stream (a) in which the hydrocarbon mixture and MTBE contained in the catalyst are eluted in methanol;
Sending the purge stream (a) to the methanol distillation column via the line (A) or to the second extractor via the line (D);
Further supplying water to the MTBE synthesis reactor to obtain a purge stream (b) in which methanol contained in the catalyst is eluted in water;
Sending the purge stream (b) to the methanol distillation column via the line (A) or to the second extractor via the line (D).

A fourth method for producing isobutylene according to the present invention is a method for producing isobutylene using the above-described fourth isobutylene production apparatus,
Supplying the hydrocarbon mixture containing isobutylene and methanol to the MTBE synthesis reactor containing the catalyst to produce isobutylene;
Stopping the supply of the hydrocarbon mixture to the MTBE synthesis reactor;
Supplying methanol to the MTBE synthesis reactor after stopping the supply of the hydrocarbon mixture to obtain a purge stream (a) in which the hydrocarbon mixture and MTBE contained in the catalyst are eluted in methanol;
The purge stream (a) is sent to the methanol distillation column via the line (A), sent to the first extractor via the line (B), or the line via the line (D). Sending to a second extractor;
Further supplying water to the MTBE synthesis reactor to obtain a purge stream (b) in which methanol contained in the catalyst is eluted in water;
The purge stream (b) is sent to the methanol distillation column via the line (A), sent to the first extractor via the line (B), or the line via the line (D). Sending to a second extractor.

  According to the present invention, there is provided an isobutylene and MTBE production apparatus capable of appropriately treating a purge flow generated when the inside of an MTBE synthesis reactor is opened to the atmosphere, and a method for producing isobutylene and MTBE using the same. Provided.

FIG. 1 is a flowchart of an isobutylene production apparatus according to the first embodiment. FIG. 2 is a flowchart of the isobutylene production apparatus according to the second embodiment. FIG. 3 is a flowchart of the MTBE manufacturing apparatus according to the third embodiment. FIG. 4 is a flowchart showing aspects of an MTBE synthesis reactor and a bypass line according to another embodiment. FIG. 5 is a flow diagram of an MTBE distillation column and other peripheral equipment according to another embodiment.

(First Embodiment: Isobutylene Production Apparatus and Method)
A method for producing isobutylene according to the first embodiment of the present invention will be described.
First, an isobutylene production apparatus 100 according to this embodiment will be described with reference to FIG.

  The production apparatus 100 includes an MTBE synthesis reactor 5, an MTBE distillation column 10, an MTBE decomposition reactor 20, a decomposition product distillation column 30, a second extractor 40, a methanol distillation column 50, a first extractor 60, and a bypass line. A1a to A1c, A2, B, and C are mainly provided.

  A methanol source MeOH and a hydrocarbon mixture source C4 are connected to the inlet 5i of the MTBE synthesis reactor 5 to supply the MTBE raw material. The MTBE synthesis reactor 5 is preferably a reactor filled with a catalyst in a container. The MTBE synthesis reactor 5 can be a fixed bed reactor filled with a catalyst in a vessel. The direction of the gas flow is not limited, and may be an up flow or a down flow.

  An example of a catalyst used in a reaction for synthesizing MTBE from methanol and isobutylene is an acidic ion exchange resin. Examples of the acidic ion exchange resin include a styrene sulfonic acid resin crosslinked with divinylbenzene and a phenol sulfonic acid resin crosslinked with formaldehyde. The acidic ion exchange resin is preferably a macroporous resin.

  The outlet 5o of the MTBE synthesis reactor 5 and the inlet 10i of the MTBE distillation column 10 are connected by a line L1. A line L2 is connected to the top outlet 10t of the MTBE distillation column 10, a line L3 is connected to the bottom outlet 10b, and a line L4 is connected to the side outlet 10s on the side of the tower.

  An inlet 60i of the first extractor 60 is connected to the line L2. An inlet 20i of the MTBE decomposition reactor 20 is connected to the line L4.

  The outlet 20o of the MTBE decomposition reactor 20 and the inlet 30i of the decomposition product distillation column 30 are connected via a line L5. The MTBE decomposition reactor 20 is a reactor filled with a solid catalyst described later, and can decompose MTBE into isobutylene and methanol.

A line L6 is connected to the top outlet 30t of the decomposition product distillation tower 30, and a line L7 is connected to the bottom outlet 30b. The line L6 is connected to the inlet 40i of the second extractor 40. The line L7 is connected to the inlet 50ia of the methanol distillation column 50.
A line L14 for supplying water is connected to the water inlet 40wi of the second extractor 40. A line L8 is connected to the oil phase outlet 40oo at the top of the second extractor 40, and a line L9 is connected to the aqueous phase outlet 40wo at the bottom.

  A line L20 for supplying water is connected to the water inlet 60wi of the first extractor 60. A line L15 is connected to the oil phase outlet 60t at the top of the first extractor 60, and a line L13 is connected to the aqueous phase outlet 60b at the bottom of the tower.

  The line L7 from the decomposition product distillation column 30 is connected to the inlet 50ia of the methanol distillation column 50, and the line L9 from the second extractor 40 and the line L13 from the first extractor 60 are the inlet of the methanol distillation column 50. Connected to 50ib. A line L10 is connected to the top outlet 50t of the methanol distillation column 50, and a line L11 is connected to the bottom outlet 50b.

  The line L7 is preferably connected to a position higher than the lines L9 and L13 with respect to the methanol distillation column 50. In other words, the inlet 50ia is preferably lower than the inlet 50ib. The concentration of water in line L7 stream (F7) is lower than the concentration of water in line L9 stream (F8) and line L13 stream (F3). Separation efficiency of water and methanol is increased.

  The methanol distillation column 50 may be a packed column, but is preferably a tray column having a plurality of stages (tray) 50a. In the case of a tray column, it is preferable that the stage 50a to which the line L7 is connected to the methanol distillation column 50 be higher than the stage 50a to which the line L9 and the line L13 are connected. The difference in the number of stages may be one or more, and may be two or more. The total number of plate towers can be 40 to 60, for example.

  The line L10 is provided with a heat exchanger 58 that condenses methanol into a liquid and a tank 55 that stores liquid methanol. The tank 55 is provided with a reflux line L18 for refluxing the liquid in the tank to the methanol distillation column 50, and a line L12 for discharging the liquid in the tank 55 to the outside.

  The bypass line A1a is a line connecting the line L1 and the line L7, the bypass line A1b is a line connecting the line L1 and the line L13, and the bypass line A1c is a line connecting the line L1 and the line L9. Lines for connecting, respectively, MTBE synthesis reactor 5 and methanol distillation column 50, MTBE distillation column 10, MTBE decomposition reactor 20, second extractor 40, decomposition product distillation column 30, and first extraction The connection is made without going through the device 60.

  The bypass line A2 is a line connecting the line L1 and the tank 55, and the MTBE synthesis reactor 5 and the methanol distillation column 50 are replaced with the MTBE distillation column 10, the MTBE decomposition reactor 20, the second extractor 40, It connects via the tank 55 and the reflux line L18, without passing through the decomposition product distillation column 30 and the 1st extractor 60. FIG.

  The bypass line B is a line that connects the line L1 and the line L2, and connects the MTBE synthesis reactor 5 and the first extractor 60 without going through the MTBE distillation column 10.

  The bypass line C is a line connecting the line L1 and the line L5, and connects the MTBE synthesis reactor 5 and the decomposition product distillation column 30 without passing through the MTBE distillation column 10 and the MTBE decomposition reactor 20. .

  In the state where MTBE is synthesized in the MTBE synthesis reactor 5, these bypass lines A1a, A1b, A1c, A2, B, and C are closed.

(Method for producing isobutylene)
Then, the manufacturing method of isobutylene concerning this embodiment is demonstrated first.

(Generation of a stream containing MTBE (F0) in the MTBE synthesis reactor 5)
First, a hydrocarbon mixture and methanol are fed to the MTBE synthesis reactor 5 to obtain a stream (F0) containing MTBE, the hydrocarbon mixture and methanol.

  The hydrocarbon mixture includes isobutylene and hydrocarbons other than isobutylene. Examples of hydrocarbon mixtures are C4 hydrocarbon fractions obtained from naphtha steam cracking (C4 fractions) or 1,3-butadiene removed therefrom by extraction or selective hydrogenation (Spent BB fractions). ); Hydrocarbon mixture having 4 carbon atoms obtained by fluid catalytic cracking (FCC-C4); a mixture containing isobutylene obtained by dehydrogenating isobutane; tert-butyl alcohol (hereinafter referred to as “TBA”). And a mixture containing isobutylene obtained by skeletal isomerization of 1-butene or 2-butene; and a mixture thereof. Examples of hydrocarbons other than isobutylene include hydrocarbons having 4 carbon atoms such as isobutane, n-butane, 1-butene, 2-butene and 1,3-butadiene; those having 3 carbon atoms such as propane, propylene, propadiene and propyne. Hydrocarbons: C5 hydrocarbons such as pentane, pentene, and isopentane. It is.

  The reaction temperature for MTBE synthesis can be 20 to 90 ° C., and the reaction pressure can be 0.2 to 2.5 MPa.

  The stream (F0) obtained by synthesis contains compounds other than MTBE, hydrocarbon mixtures and methanol. Examples of the compound are alcohols other than methanol and ethers other than MTBE.

  Examples of hydrocarbon mixtures contained in the stream (F0) are hydrocarbons having 4 carbon atoms such as isobutylene, isobutane, n-butane, 1-butene, 2-butene, 1,3-butadiene; carbon numbers such as diisobutylene 8 hydrocarbons; hydrocarbons having 3 carbon atoms such as propane, propylene, propadiene and propyne; hydrocarbons having 5 carbon atoms such as pentane, pentene and isopentane.

  An example of an alcohol other than methanol is TBA.

  Examples of ethers other than MTBE are dimethyl ether and methyl-sec-butyl ether.

  The stream (F0) can contain water.

  The concentration of MTBE in the stream (F0) can be 10 to 97% by weight.

(Distillation in the MTBE distillation column 10 of the stream (F0))
The stream (F0) is then fed to the MTBE distillation column 10 via line L1. The temperature of the stream (F0) at the inlet of the MTBE distillation column 10 can be 25-490 ° C. The pressure in the MTBE distillation column 10 can be 0.1 to 1.2 MPa.

  By distilling the stream (F0) in the MTBE distillation column 10, a stream (F6) containing mainly a hydrocarbon mixture and containing methanol is discharged from the top of the column via line L2, and diisobutylene, methyl-sec is discharged from the bottom of the column. A stream (F17) mainly containing high-boiling compounds such as butyl ether is discharged via line L3, and a stream (F1) mainly containing MTBE from below the column top and above the column bottom via line L4 To discharge.

  In order to stably discharge the middle distillate stream (F1) from the line L4 from the MTBE distillation column 10, the MTBE distillation column 10 can be a plate column having a plurality of trays. Thereby, the middle distillate can be suitably discharged from the tray. The temperature at the outlet of the MTBE distillation column 10 of the stream (F1) discharged through the line L4, that is, the temperature of the tray for side-cutting the liquid can be 80 to 200 ° C.

(Methanol extraction from stream F6 in first extractor 60)
The flow (F6) is converted into a liquid phase by heat exchange, and then supplied to the first extractor 60 via the line L2, and liquid water is supplied to the first extractor 60 via the line L20. By contact with water, methanol present in the stream (F6) is dissolved in water and extracted, and the stream (F3) is discharged from the bottom of the tower as a mixture of water and methanol through the line L13.

  On the other hand, the stream (F12) containing the hydrocarbon mixture that is the oil phase is discharged from the top of the column via the line L15 in a state where the methanol is sufficiently removed.

  The temperature of the 1st extractor 60 can be 15-80 degreeC, and a pressure can be 0.2-1.0 MPa-G. The temperature of the stream (F3) at the bottom outlet of the first extractor 60 can be 30 to 80 ° C.

(Decomposition of MTBE in MTBE decomposition reactor 20)
Next, the stream (F1) generated in the MTBE distillation column 10 is supplied to the MTBE cracking reactor 20 via a line L4.

  In the MTBE cracking reactor 20, MTBE in the stream (F1) is decomposed to obtain a stream (F2A (F2)) containing isobutylene and methanol. It is sufficient that at least a part of the MTBE in the stream (F1) is decomposed, and all of the MTBE in the stream (F1) may be decomposed. The stream containing isobutylene and methanol (F2A) usually contains undecomposed MTBE.

  It is preferred to feed the stream (F1) as a gas to the MTBE cracking reactor 20. The temperature of the stream (F1) at the inlet of the MTBE cracking reactor 20 can be 100-500 ° C.

MTBE can be decomposed by a gas phase reaction using a fixed bed type MTBE decomposition reactor. The reaction temperature is usually 100 to 500 ° C, preferably 150 to 350 ° C. The reaction pressure is usually atmospheric pressure to 2.0 MPa-G (gauge pressure), preferably atmospheric pressure to 1.2 MPa-G. Feed rate of the raw material is the reaction temperature, pressure, and is selected by the conversion or the like MTBE, usually 0.1～50H ^-1 at a weight hourly space velocity (WHSV), and preferably is 1～20H ^-1 employed. WHSV is the flow rate (kg / h) of all streams subjected to the MTBE decomposition step divided by the catalyst weight (kg).

  The conversion rate of MTBE in the MTBE decomposition step is preferably 40% to 99%, more preferably 70% to 98%, and still more preferably 85% to 96%.

In the MTBE decomposition step, a solid catalyst is usually used. Examples of the solid catalyst include metal oxides, nonmetal oxides, and composite oxides. Examples of the metal oxide include alumina, titanium oxide, and chromium oxide. Examples of the non-metal oxide include silicon dioxide. Examples of the composite oxide include silica alumina and zeolite. These may be crystalline or amorphous, and may contain elements such as sulfur, phosphorus, magnesium, calcium, sodium, and potassium. The solid catalyst used in the MTBE decomposition step preferably contains 4 to 30% by mass of aluminum source in terms of aluminum oxide and 60 to 95% by mass of silicon source in terms of silicon dioxide, and is 50 to 450 m ² / g. Silica alumina having a BET surface area is used.

  The MTBE decomposition step is preferably performed using silica alumina at 100 ° C. or more and 500 ° C. or less. Since this reaction is an endothermic reaction, it is necessary to supply heat from the outside. The heat may be supplied by supplying a heat medium from the outside to the heat transfer tube provided in the MTBE decomposition reactor 20, or the flow (F1) may be heated and supplied as sensible heat, These may be combined.

  The temperature of the stream (F2A) at the outlet of the MTBE cracking reactor 20 discharged via the line L5 can be 100 to 500 ° C, preferably 150 to 350 ° C.

  Water may be added to the flow (F1) flowing through the line L4 and then supplied to the MTBE decomposition reactor 20. The amount of water added is preferably 0 to 10% by mass, more preferably 0.2 to 5.0% by mass with respect to the amount discharged from the MTBE distillation column 10.

(Separation of methanol from the stream (F2A) in the decomposition product distillation column 30)
Next, the stream (F2A) is supplied to the decomposed product distillation column 30 via the line L5.

  The inlet temperature of the stream (F2A) decomposition product distillation column 30 can be 20 to 480 ° C, preferably 20 to 330 ° C.

  Part of the methanol in the stream (F2A) is separated by distillation in the cracked product distillation column 30. A stream (F7) mainly containing methanol is discharged from the bottom of the cracked product distillation column 30 via the line L7. A stream mainly composed of isobutylene (F2B (F2)) from which a part of methanol is separated from the top of the cracked product distillation column 30 via a line L6 is discharged. Even in a stream mainly composed of isobutylene from which a part of methanol is separated (F2B), methanol is usually included in addition to isobutylene. The methanol content in stream (F2B) is less than the methanol content in stream (F7). The stream mainly composed of methanol (F7) usually contains undecomposed MTBE in addition to methanol.

  The temperature at the top of the decomposition product distillation tower 30 can be 10 to 110 ° C. The temperature of the bottom of the decomposition product distillation column 30 can be set to 80 to 200 ° C. The pressure of the decomposition product distillation column 30 can be 0.1-2.0 MPa-G.

(Extraction of methanol from isobutylene with water in the second extractor 40)
Next, the flow (F2B) is converted into a liquid phase by heat exchange, and then supplied to the second extractor 40 via the line L6 and liquid water is supplied to the second extractor 40 via the line L14. To do. By contact with water, methanol present in the stream (F2B) is dissolved in water and extracted, and the stream (F8) is discharged as a mixture of water and methanol from the bottom of the column via the line L9.

  On the other hand, the stream (F5) containing isobutylene as an oil phase is discharged from the top of the column via line L8 in a state where methanol is sufficiently removed.

  For the stream (F5), if necessary, further purification of isobutylene may be performed by removing low boiling point compounds such as dimethyl ether by distillation or the like.

  The temperature of the 2nd extractor 40 can be 15-80 degreeC, and a pressure can be 0.2-1.0 MPa-G. The temperature of the stream (F8) at the bottom outlet of the second extractor 40 can be 30 to 80 ° C.

(Separation of water and methanol in the methanol distillation column 50)
The stream (F7) from the cracked product distillation column 30 is supplied to the methanol distillation column 50 via the line L7, and the flow (F8) from the second extractor 40 is supplied to the methanol distillation column 50 via the line L9. Stream (F3) from extractor 60 is fed to methanol distillation column 50 via line L13. As described above, it is preferable to supply the stream (F7) to the methanol distillation column 50 above the stream (F8) and the stream (F3).

  The temperature of the stream (F7) at the inlet of the methanol distillation column 50 can be 80-200 ° C. The temperature of the stream (F8) at the inlet of the methanol distillation column 50 can be 30-80 ° C. The temperature of the stream (F3) at the inlet of the methanol distillation column 50 can be 30-200 ° C.

  In the methanol distillation column 50, by distillation, a stream mainly containing methanol (F9) is discharged from the top of the tower via the line L10, and a stream mainly containing water (F10) is discharged from the bottom of the tower via the line L11. . The stream (F9) usually contains MTBE in addition to methanol.

  The temperature at the top of the column can be 60 to 150 ° C. The temperature at the bottom of the column can be 100 to 200 ° C. The pressure of the methanol distillation column 50 can be set to atmospheric pressure to 1.0 MPa-G.

  The flow (F9) is condensed in the heat exchanger 58 to form a liquid phase and stored in the tank 55. By refluxing a part of the stream (F9) to the upper part of the methanol distillation column 50 via the reflux line L18, the concentration of water in the stream (F9) can be reduced to increase the purity of methanol.

  The stream (F9) discharged through the line L12 can be used as methanol to be supplied to the MTBE synthesis reactor 5. The stream (F10) can be used as water for methanol extraction to be provided to the second extractor 40 and the first extractor 60.

(Exchange of catalyst in MTBE synthesis reactor)
As described above, when the MTBE synthesis reactor 5 is supplied with a hydrocarbon mixture and methanol to produce MTBE as a stream (F0), the activity of the catalyst in the MTBE synthesis reactor 5 may decrease with time. is there. In that case, it is necessary to exchange the catalyst in the MTBE synthesis reactor 5. Since the hydrocarbon mixture, MTBE and methanol are contained by adsorption or the like in the catalyst, a method for removing them from the catalyst before the catalyst exchange will be described below.

First, the supply of the hydrocarbon mixture to the MTBE synthesis reactor 5 is stopped.
Next, methanol is supplied to the MTBE synthesis reactor 5 to elute the hydrocarbon mixture and MTBE contained in the catalyst into the methanol, and a purge stream containing the hydrocarbon mixture, MTBE and methanol from the MTBE synthesis reactor 5 (a ). The temperature of the supplied methanol can be 10 to 150 ° C. The pressure of the MTBE synthesis reactor 5 can be 0.2 to 2.5 MPaG.

  In order to sufficiently elute the hydrocarbon mixture and MTBE contained in the catalyst into methanol, it is necessary to supply methanol with a volume of 1 or more times, preferably 10 or more times the apparent volume of the catalyst. Is preferred. Therefore, it is not preferable to incinerate the purge stream, and it is preferable to recover methanol in the purge stream. However, the MTBE distillation column 10 is not suitable for distilling a high methanol concentration stream such as the purge stream (a).

  Therefore, the purge stream (a) is sent to the methanol distillation column 50 via the bypass line A1a, A1b, A1c or A2, sent to the first extractor 60 via the bypass line B, or via the bypass line C. To the decomposition product distillation column 30.

  When the purge stream (a) is sent to the methanol distillation column 50 via the bypass lines A1a, A1b, A1c or A2, the mixture of hydrocarbon mixture, MTBE, and methanol is obtained by distillation of the purge stream (a). Is discharged from the line L10, and water is discharged from the line L11.

  When the purge stream (a) is sent to the first extractor 60 via the bypass line B, the hydrocarbon mixture and MTBE are brought into line L15 by contact of the purge stream (a) and water in the first extractor 60. And the methanol and water are discharged as a water phase via line L13 and supplied to the methanol distillation column 50. In the methanol distillation column 50, since methanol and water are separated, methanol can be recovered suitably.

  When the purge stream (a) is sent to the cracked product distillation column 30 via the bypass line C, the hydrocarbon mixture is discharged from the line L6 by distillation of the purge stream (a), and MTBE and methanol. The mixture is discharged from line L7.

If the purge stream (a) is rich in hydrocarbon mixture and MTBE, the purge stream (a) is sent to the first extractor 60 via the bypass line B and the stream (F12) is mixed with hydrocarbon mixture and MTBE. Is preferably recovered.
If the purge stream (a) contains a large amount of methanol, the purge stream (a) is sent to the methanol distillation column 50 via the bypass line A (A1a, A1b, A1c or A2) and the stream (F9) is fed with methanol. Is preferably recovered. In this case, since the purge stream (a) has a high methanol concentration, when supplying the methanol to the methanol distillation column 50, it is preferable to use the bypass line A1a connected to the inlet 50ia higher than the inlet 50ib.

  As a result, the hydrocarbon mixture and MTBE in the catalyst are sufficiently removed, but methanol is contained in the catalyst by adsorption or the like.

  Therefore, after eluting into methanol, water is further supplied to the MTBE synthesis reactor 5 to elute the methanol contained in the catalyst into water, and the water from which the methanol has eluted from the MTBE synthesis reactor 5 is purged (b ). The temperature of the supplied water can be 0 to 80 ° C. The pressure of the MTBE synthesis reactor 5 can be 0.2 to 2.0 MPaG. Normally, at the start of water supply, methanol is also supplied to the MTBE synthesis reactor 5, and the amount of water to be supplied is gradually increased, and accordingly, the amount of methanol to be supplied is decreased. Stop supply and supply only water.

  In order to sufficiently elute the methanol contained in the catalyst into water, it is preferable to supply water with a volume of 1 or more times, preferably 10 or more times the apparent volume of the catalyst. Therefore, it is not preferable to discharge the purge stream (b) out of the system, and it is preferable to separate and recycle methanol and water in the purge stream. However, the MTBE distillation column 10 is not suitable for distilling a stream having a high water concentration such as a purge stream (b).

  Therefore, the purge stream (b) is sent to the methanol distillation column 50 via the bypass line A1a, A1b, A1c or A2, sent to the first extractor 60 via the bypass line B, or via the bypass line C. To the decomposition product distillation column 30.

  When the purge stream (b) is sent to the methanol distillation column 50 via the bypass line A1a, A1b, A1c or A2, methanol is discharged from the line L10 and water is discharged from the line L11 by distillation.

  When the purge flow (b) is sent to the first extractor 60 via the bypass line B, the purge flow (b) and water come into contact with the first extractor 60, but an oil phase is almost formed. Instead, the purge stream (b) is discharged as an aqueous phase containing methanol and water via the line L13 and supplied to the methanol distillation column 50. In the methanol distillation column 50, methanol and water are separated, so that methanol can be suitably recovered and water can be reused.

  When the purge stream (b) is sent to the cracked product distillation column 30 via the bypass line C, the hydrocarbon mixture is discharged from the line L6 by distillation of the purge stream (b), MTBE, methanol and A mixture of water is discharged from line L7.

  Thereby, in addition to the hydrocarbon mixture and MTBE in the catalyst, methanol is also sufficiently removed.

  Subsequently, the inside of the MTBE synthesis reactor is opened to the atmosphere to exchange the catalyst.

  After exchanging the catalyst, the MTBE synthesis reactor 5 is washed with water and replaced with methanol, and then the supply of methanol and hydrocarbon mixture is started, and then MTBE synthesis can be resumed.

  In addition, as a method for removing the hydrocarbon mixture, MTBE, and methanol contained in the catalyst before the catalyst replacement, the following methods may be mentioned in addition to the above methods.

  First, the supply of the hydrocarbon mixture and methanol to the MTBE synthesis reactor 5 is stopped. Next, the hydrocarbon mixture, methanol, and MTBE remaining in the MTBE synthesis reactor 5 are discharged from the MTBE synthesis reactor 5. This extraction can be performed by a liquid drain line L22 provided in the MTBE synthesis reactor 5. Since the amount of the extracted liquid is small and flammable, this liquid can be incinerated appropriately.

  Even after the liquid remaining in the MTBE synthesis reactor 5 is discharged, a hydrocarbon mixture, MTBE, and methanol are contained in the catalyst by adsorption or the like. Therefore, next, methanol is supplied to the MTBE synthesis reactor 5 to elute the hydrocarbon mixture and MTBE contained in the catalyst into the methanol, and the MTBE synthesis reactor 5 purges the hydrocarbon mixture, MTBE and methanol. Drain (a). The temperature of methanol to be supplied, the volume of methanol, and the pressure of the MTBE synthesis reactor 5 are the same as described above. The purge stream (a) is sent to the methanol distillation column 50 via the bypass line A1a, A1b, A1c or A2, sent to the first extractor 60 via the bypass line B, or decomposed product via the bypass line C. The method of sending to the distillation column 30 is also the same as described above.

  After the hydrocarbon mixture and MTBE in the catalyst are sufficiently removed, water is further supplied to the MTBE synthesis reactor 5 to elute methanol contained in the catalyst into water, and methanol is eluted from the MTBE synthesis reactor 5. The discharged water is discharged as a purge stream (b). The temperature of the supplied water, the volume of water, the pressure of the MTBE synthesis reactor 5 and the like are the same as described above. The purge stream (b) is sent to the methanol distillation column 50 via the bypass line A1a, A1b, A1c or A2, sent to the first extractor 60 via the bypass line B, or decomposed product via the bypass line C. The method of sending to the distillation column 30 is also the same as described above. In this method, in addition to the hydrocarbon mixture and MTBE in the catalyst, methanol is also sufficiently removed.

(Function)
According to this embodiment, the bypass lines A1a, A1b, A1c, A2, B, or C are provided. Thus, the purge stream eluting the combustible compound contained in the catalyst of the MTBE synthesis reactor 5 is converted into the MTBE distillation column 10, the MTBE decomposition reactor 20, the decomposition product distillation column 30, the second extractor 40, and , Supply to the methanol distillation column 50 without passing through the first extractor 60, supply to the cracked product distillation column 30 without passing through the MTBE distillation column 10 and the MTBE decomposition reactor 20, or the MTBE distillation column 10 Can be supplied to the first extractor 60 without going through.

  Accordingly, the purge stream can be appropriately processed and recycled without adversely affecting the MTBE distillation column 10, the decomposed product distillation column 30, and the like.

(Second Embodiment)
With reference to FIG. 2, the manufacturing method of the isobutylene concerning 2nd Embodiment of this invention is demonstrated.
Differences of the present invention from the first embodiment will be described. FIG. 2 is a flowchart of the isobutylene production apparatus 200 of the present embodiment.

  In the isobutylene production apparatus 200 of the present embodiment, the line L5 is connected to the inlet 40i of the second extractor 40 instead of the inlet 30i of the decomposition product distillation column 30. A stream (F5) discharged from the oil phase outlet 40oo at the top of the second extractor 40 via the line L8 is supplied to the inlet 30i of the decomposition product distillation tower 30. The stream (F8) discharged from the aqueous phase outlet 40wo at the bottom of the second extractor 40 is supplied to the inlet 50ib of the methanol distillation tower 50 via the line L9. The stream (F27) discharged from the bottom outlet 30b of the decomposition product distillation tower 30 via the line L7 is not sent to the methanol distillation tower 50 but sent to the incineration boiler.

The bypass line A1b is a line connecting the line L1 and the line L13, the bypass line A1c is a line connecting the line L1 and the line L9, and the bypass line A1d is an inlet of the line L1 and the methanol distillation column 50. 50ia, these are the MTBE synthesis reactor 5 and the methanol distillation column 50, the MTBE distillation column 10, the MTBE decomposition reactor 20, the second extractor 40, the decomposition product distillation column 30, and The connection is made without going through the first extractor 60.
The bypass line B is the same as in the first embodiment.

  The bypass line D is a line that connects the line L1 and the line L5, and connects the MTBE synthesis reactor 5 and the second extractor 40 without passing through the MTBE distillation column 10 and the MTBE decomposition reactor 20. .

  Subsequently, the difference between the MTBE and isobutylene production method of the present embodiment and the first embodiment will be described.

(Extraction of methanol from isobutylene with water in the second extractor 40)
The stream (F2) discharged from the MTBE decomposition reactor 20 is supplied to the second extractor 40 via the line L5, and liquid water is supplied to the second extractor 40 via the line L14. By contact with water, the methanol in stream (F2) is dissolved in water and extracted from isobutylene, and stream (F8) is discharged from the bottom of the tower as a mixture of water and methanol via line L9.

  On the other hand, the stream (F5) containing isobutylene as the oil phase from which methanol has been removed is discharged from the top of the column via line L8. The stream (F5) containing isobutylene usually contains high-boiling compounds such as MTBE and diisobutylene in addition to isobutylene.

  The temperature of the stream (F2) at the inlet of the second extractor 40 can be 30-480 ° C. The temperature of the 2nd extractor 40 can be 15-80 degreeC, and a pressure can be 0.2-1.0 MPa-G.

(Separation of isobutylene and high boiling point compound in the decomposition product distillation column 30)
Next, the stream (F5) containing isobutylene is supplied to the cracked product distillation column 30 via the line L8. The temperature of the stream (F5) at the inlet of the cracked product distillation column 30 can be 15 to 80 ° C.

  Distillation in the cracked product distillation column 30 discharges the main stream (F26) of isobutylene from the top of the cracked product distillation column 30 via the line L6, and from the bottom of the cracked product distillation column 30 via the line L7. Thus, a stream (F27) containing a high-boiling compound such as diisobutylene is discharged. The stream (F27) is usually incinerated.

  The temperature at the top of the decomposition product distillation column 30, the temperature at the bottom of the column, and the pressure of the decomposition product distillation column 30 can be the same as those in the first embodiment.

(Separation of water and methanol in the methanol distillation column 50)
In the methanol distillation column 50, the stream (F3) and the stream (F8) are distilled. The temperature of the stream (F8) at the inlet of the methanol distillation column 50, the temperature of the stream (F3) at the inlet of the methanol distillation column 50, the temperature at the top of the methanol distillation column 50, the temperature at the bottom of the column, and the methanol distillation column 50 The various conditions of the methanol distillation column 50, such as the pressure, and the subsequent distillation in the methanol distillation column 50 are the same as in the first embodiment. According to this method, high-purity methanol having a lower MTBE content than that of the first embodiment can be obtained.

Also in this embodiment, the catalyst of the MTBE synthesis reactor 5 can be exchanged using the bypass lines A1b, A1c, A1d, A2, B, or D as in the first embodiment.
When the purge stream (a) is sent to the second extractor 40 via the bypass line D, the hydrocarbon mixture and MTBE are brought into line L8 by the contact of the purge stream (a) and water in the second extractor 40 The methanol and water are discharged as a water phase via line L9 and supplied to the methanol distillation column 50. In the methanol distillation column 50, since methanol and water are separated, methanol can be recovered suitably.
If the purge stream (a) is rich in hydrocarbon mixture and MTBE, the purge stream (a) is sent to the first extractor 60 via the bypass line B and the stream (F12) is mixed with hydrocarbon mixture and MTBE. Is preferably recovered.
If the purge stream (a) contains a large amount of methanol, the purge stream (a) is sent to the methanol distillation column 50 via the bypass line A (A1b, A1c, A1d, A2), and methanol (F9) Is preferably recovered. In this case, since the purge stream (a) has a high methanol concentration, when the purge stream (a) is supplied to the methanol distillation column 50 via the bypass line A, the purge stream (a) is connected to the inlet 50ia higher than the inlet 50ib. It is preferable to use the bypass line A1d.

  When the purge stream (b) is sent to the second extractor 40 via the bypass line D, the purge stream (b) and water come into contact with the second extractor 40, but the oil phase is almost formed. Instead, the purge stream (b) is discharged as a water phase containing methanol and water via the line L9 and supplied to the methanol distillation column 50. In the methanol distillation column 50, methanol and water are separated, so that methanol can be suitably recovered and water can be reused.

(Third embodiment)
An MTBE manufacturing method according to the third embodiment of the present invention will be described.
First, an MTBE manufacturing apparatus 300 according to this embodiment will be described with reference to FIG.

  The production apparatus 100 mainly includes an MTBE synthesis reactor 5, an MTBE distillation column 10, a methanol distillation column 50, a first extractor 60, and bypass lines A1b, A2, and B.

  The MTBE synthesis reactor 5, the MTBE distillation column 10, the methanol distillation column 50, the first extractor 60, and their connection relationship are the same as those in the first embodiment except that the line L13 is directly connected to the methanol distillation column 50. It is the same.

  The bypass line A1b is a line connecting the line L1 and the line L13, and the bypass line A1d is a line connecting the line L1 and the inlet 50ia of the methanol distillation column 50, and these are the MTBE synthesis reactor 5 And the methanol distillation column 50 are connected without passing through the MTBE distillation column 10 and the first extractor 60.

  The bypass line A2 is a line connecting the line L1 and the tank 55, and the MTBE synthesis reactor 5 and the methanol distillation column 50 are not connected to the tank without passing through the MTBE distillation column 10 and the first extractor 60. 55 and the reflux line L18.

  The bypass line B is a line that connects the line L1 and the line L2, and connects the MTBE synthesis reactor 5 and the first extractor 60 without going through the MTBE distillation column 10.

  In the state in which MTBE is synthesized in the MTBE synthesis reactor 5, these bypass lines A1b, A2, and B are closed.

(Manufacturing method of MTBE)
Next, a method for manufacturing MTBE according to the present embodiment will be described.

  First, as in the first embodiment, the MTBE synthesis reactor 5 generates an MTBE-containing stream (F0), and the MTBE distillation column 10 distills the stream (F0) to form a stream (F6), a stream (F1), Then, the flow (F17) is generated, and the first extractor 60 generates the flow (F3) and the flow (F12) from the flow (F6). Since various conditions of each process are the same as those in the first embodiment, description thereof is omitted.

(Exchange of catalyst in MTBE synthesis reactor)
As described above, when the MTBE synthesis reactor 5 is supplied with a hydrocarbon mixture and methanol to produce MTBE as a stream (F5), the activity of the catalyst in the MTBE synthesis reactor 5 may decrease with time. is there. In that case, it is necessary to exchange the catalyst in the MTBE synthesis reactor 5. Since the hydrocarbon mixture, MTBE and methanol are contained by adsorption or the like in the catalyst, it is preferable to remove them from the catalyst before exchanging the catalyst. Hereinafter, this method will be described.

  First, the supply of the hydrocarbon mixture to the MTBE synthesis reactor 5 is stopped. Next, methanol is supplied to the MTBE synthesis reactor 5 to elute the hydrocarbon mixture and MTBE contained in the catalyst into the methanol, and a purge stream containing the hydrocarbon mixture, MTBE and methanol from the MTBE synthesis reactor 5 (a ). The temperature of methanol to be supplied and the pressure of the MTBE synthesis reactor 5 can be the same as those in the first embodiment.

  In order to sufficiently elute the hydrocarbon mixture and MTBE contained in the catalyst into methanol, it is necessary to supply methanol with a volume of 1 or more times, preferably 10 or more times the apparent volume of the catalyst. Is preferred. Therefore, it is not preferable to incinerate the purge stream, and it is preferable to recover methanol in the purge stream. However, the MTBE distillation column 10 is not suitable for distilling a high methanol concentration stream such as the purge stream (a).

  Therefore, the purge stream (a) is sent to the methanol distillation column 50 via the bypass line A1b, A1d or A2, or sent to the first extractor 60 via the bypass line B.

  When the purge stream (a) is sent to the methanol distillation column 50 via the bypass lines A1b, A1d, or A2, the mixture of hydrocarbon mixture, MTBE, and methanol is obtained by distillation of the purge stream (a). The water is discharged from the line L10, and the water is discharged from the line L11.

  When the purge stream (a) is sent to the first extractor 60 via the bypass line B, the hydrocarbon extractor and MTBE are lined in the first extractor 60 due to contact between the purge stream (a) and water. It is discharged as an oil phase via L15, and methanol and water are discharged as a water phase via line L13 and supplied to the methanol distillation column 50. In the methanol distillation column 50, since methanol and water are separated, methanol can be recovered suitably.

If the purge stream (a) is rich in hydrocarbon mixture and MTBE, the purge stream (a) is sent to the first extractor 60 via the bypass line B and the stream (F12) is mixed with hydrocarbon mixture and MTBE. Is preferably recovered.
If the purge stream (a) contains a large amount of methanol, the purge stream (a) is sent to the methanol distillation column 50 via the bypass line A (A1b, A1d, A2) and methanol is recovered in the stream (F9). It is preferable to do. In this case, since the purge stream (a) has a high methanol concentration, when supplying to the methanol distillation column 50, it is preferable to use the bypass line A1d connected to the inlet 50ia higher than the inlet 50ib.

  As a result, the hydrocarbon mixture and MTBE in the catalyst are sufficiently removed, but methanol is contained in the catalyst by adsorption or the like.

  Therefore, after eluting into methanol, water is further supplied to the MTBE synthesis reactor 5 to elute the methanol contained in the catalyst into water, and the water from which the methanol has eluted from the MTBE synthesis reactor 5 is purged (b ). The temperature of the supplied water and the pressure of the MTBE synthesis reactor 5 can be the same as in the first embodiment. Usually, at the start of water supply, methanol is also supplied to the MTBE synthesis reactor 5, and the amount of water to be supplied is gradually increased, and accordingly, the amount of methanol to be supplied is decreased. Stop supply and supply only water.

  In order to sufficiently elute the methanol contained in the catalyst into water, it is preferable to supply water with a volume of 1 or more times, preferably 10 or more times the apparent volume of the catalyst. Therefore, it is not preferable to discharge the purge stream (b) out of the system, and it is preferable to separate and recycle methanol and water in the purge stream. However, the MTBE distillation column 10 is not suitable for distilling a stream having a high water concentration such as a purge stream (b).

  Therefore, the purge stream (b) is sent to the methanol distillation column 50 via the bypass line A1b, A1d, or A2, or sent to the first extractor 60 via the bypass line B.

  When the purge stream (b) is sent to the methanol distillation column 50 via the bypass lines A1b, A1d, or A2, methanol is discharged from the line L10 and water is discharged from the line L11 by distillation.

  When the purge flow (b) is sent to the first extractor 60 via the bypass line B, the purge flow (b) and water come into contact with the first extractor 60, but almost the oil phase is formed. Instead, the purge stream (b) is discharged as a water phase containing methanol and water via the line L13 and supplied to the methanol distillation column 50. In the methanol distillation column 50, methanol and water are separated, so that methanol can be suitably recovered and water can be reused.

  Thereby, in addition to the hydrocarbon mixture and MTBE in the catalyst, methanol is also sufficiently removed.

  Subsequently, the inside of the MTBE synthesis reactor is opened to the atmosphere to exchange the catalyst.

  After exchanging the catalyst, the MTBE synthesis reactor 5 is washed with water and replaced with methanol, and then the supply of methanol and hydrocarbon mixture is started, and then MTBE synthesis can be resumed.

  In addition, as a method for removing the hydrocarbon mixture, MTBE, and methanol contained in the catalyst before the catalyst replacement, the following methods may be mentioned in addition to the above methods.

  First, the supply of the hydrocarbon mixture and methanol to the MTBE synthesis reactor 5 is stopped. Next, the hydrocarbon mixture, methanol, and MTBE remaining in the MTBE synthesis reactor 5 are discharged from the MTBE synthesis reactor 5. This extraction can be performed by a liquid drain line L22 provided in the MTBE synthesis reactor 5. Since the amount of the extracted liquid is small and flammable, this liquid can be incinerated appropriately.

  Even after the liquid remaining in the MTBE synthesis reactor 5 is discharged, a hydrocarbon mixture, MTBE, and methanol are contained in the catalyst by adsorption or the like. Therefore, next, methanol is supplied to the MTBE synthesis reactor 5 to elute the hydrocarbon mixture and MTBE contained in the catalyst into methanol, and the MTBE synthesis reactor 5 purges the hydrocarbon mixture, MTBE and methanol. Drain (a). The temperature of methanol to be supplied, the volume of methanol, and the pressure of the MTBE synthesis reactor 5 are the same as described above. The method of sending the purge stream (a) liquid to the methanol distillation column 50 via the bypass line A1b, A1d, or A2 or sending it to the first extractor 60 via the bypass line B is the same as described above.

  After the hydrocarbon mixture and MTBE in the catalyst are sufficiently removed, water is further supplied to the MTBE synthesis reactor 5 to elute methanol contained in the catalyst into water, and methanol is eluted from the MTBE synthesis reactor 5. The discharged water is discharged as a purge stream (b). The temperature of the supplied water, the volume of water, the pressure of the MTBE synthesis reactor 5 and the like are the same as described above. The method of sending the purge stream (b) liquid to the methanol distillation column 50 via the bypass lines A1b, A1d and A2 or to the first extractor 60 via the bypass line B is the same as described above. In this method, in addition to the hydrocarbon mixture and MTBE in the catalyst, methanol is also sufficiently removed.

(Function)
According to the present embodiment, the bypass line A1b, A1d, A2, or B is provided. Thus, the purge flow eluting the combustible compound contained in the catalyst of the MTBE synthesis reactor 5 is supplied to the methanol distillation column 50 without passing through the MTBE distillation column 10 and the first extractor 60. Or can be supplied to the first extractor 60 without going through the MTBE distillation column 10.

  Thus, the purge stream can be appropriately processed and recycled without adversely affecting the MTBE distillation column 10.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, the MTBE synthesis reactor 5 can have a plurality of unit reactors connected in series. For example, as shown in FIG. 4, the MTBE synthesis reactor 5 includes a unit reactor 5A, a unit reactor 5B, and a unit reactor 5C, which are connected in series in series from the upstream side. The bypass lines A1a, A1b, A1c, A1d, A2, B, C, D are not only branched after the unit reactor 5C, but also between the unit reactor 5A and the unit reactor 5B. You may branch from the line and / or the line between the unit reactor 5B and the unit reactor 5C.

  For example, when exchanging the catalysts of all the unit reactors 5A, 5B, 5C, a bypass line connected downstream of the unit reactor 5C can be used. In addition, when only the catalysts of the unit reactors 5A and 5B are exchanged, the use of a bypass line branched from the line between the unit reactor 5B and the unit reactor 5C may affect the unit reactor 5C. It is possible to replace the catalyst. In addition, when only the catalyst of the unit reactor 5A is exchanged, use of a bypass line branched from the line between the unit reactor 5A and the unit reactor 5B may affect the unit reactors 5B and 5C. The catalyst can be replaced without any change.

  In particular, from the viewpoint that the catalyst of the most upstream unit reactor is likely to deteriorate, a bypass line branches from the line between the most upstream unit reactor and the second unit reactor counted from the most upstream side. Is preferably provided.

  Moreover, in the said embodiment, although it has several bypass lines, you may have only any one.

  Further, the connection form of the bypass line is not limited to the illustrated one. In this specification, “the line connecting the A device and the B device without going through the C device” means that the A device and the B device are connected as long as the A device and the B device are connected without going through the C device. May be a line that directly connects the A device and the B device through another line or device.

  For example, in the first to third embodiments, the bypass line A1a, A1b, or A1c connects the line L1 and the line L7, the line L13, or the line L9, but the line L1 and the inlet of the methanol distillation column 50 (for example, , 50ia or 50ib), the outlet 5o of the MTBE synthesis reactor 5 and the line L13, L7 or L9, or the outlet 5o of the MTBE synthesis reactor 5 and methanol. You may connect with the inlet_port | entrance (for example, 50ia or 50ib) of the distillation column 50. FIG.

  In the second to third embodiments, the bypass line A1d connects the line L1 and the inlet 50ia of the methanol distillation column 50, but the outlet 5o of the MTBE synthesis reactor 5 and the inlet 50ia of the methanol distillation column 50 are connected. And may be connected.

  In the above embodiment, the bypass line A2 connects the line L1 and the tank 55, but the line L1 and the line L10 may be connected, or the line L1 and the reflux line L18 may be connected. The outlet 5o of the MTBE synthesis reactor 5 may be connected to the tank 55, and the outlet 5o of the MTBE synthesis reactor 5 may be connected to the line L10 or the reflux line L18.

  In the above embodiment, the bypass line B connects the line L1 and the line L2, but the outlet 5o of the MTBE synthesis reactor 5 and the inlet 60i of the first extractor 60 may be connected. The line L1 and the inlet 60i may be connected, or the outlet 5o and the line L2 may be connected.

  Moreover, in the said embodiment, although the bypass line C has connected the line L1 and the line L5, you may connect the line L1 and the inlet_port | entrance (for example, 30i) of the decomposition product distillation column 30, and MTBE synthesis reaction The outlet 5o of the vessel 5 and the inlet (for example, 30i) of the decomposition product distillation column 30 may be connected.

  In the above embodiment, the bypass line D connects the line L1 and the line L5, but the line L1 and the inlet (for example, 40i) of the second extractor 40 may be connected, and the MTBE synthesis reaction The outlet 5o of the vessel 5 and the inlet (for example, 40i) of the second extractor 40 may be connected.

  In the above embodiment, the inlet 50ia and the inlet 50ib of the methanol distillation column 50 are different in height, but can be implemented even if they are the same.

  Further, in this specification, “the device B has an inlet connected to the outlet of the device A” means that the outlet of the device A and the inlet of the device B are connected without passing through another processing device. This includes not only the case of being connected but also the case of being connected through another processing device. Other processing apparatuses include, for example, a post-reactor that reacts unreacted components again, and a separation apparatus such as a distillation column that reduces the concentration of secondary components.

  For example, in the line L2 in the first to third embodiments, the second MTBE synthesis in which MTBE is generated by reacting unreacted methanol and C4 hydrocarbon in the stream (F6) discharged from the top outlet 10t. You may have a reactor. Even in this case, the first extractor 60 has an inlet 60 i connected to the top outlet 10 t of the MTBE distillation column 10.

In the above embodiment, the MTBE distillation column 10 has a low-boiling point compound from the column top outlet 10t through the line L2, a high-boiling compound from the column bottom outlet 10b through the line L3, and a line L4 from the middle side outlet 10s. In this case, the MTBE distillation column 10 having no side outlet 10s may be employed as shown in FIG. When using the MTBE distillation column 10 without the side outlet 10s, the bottom outlet 10b may be directly connected to the inlet 20i of the MTBE cracking reactor 20, but the MTBE is connected via one or more additional distillation columns. It is preferable to connect to the inlet 20i of the cracking reactor 20. For example, as shown in FIG. 5, in the first MTBE distillation column 10, a low boiling point compound is extracted from the top outlet 10t, and a middle distillate mainly composed of the high boiling point compound and MTBE is extracted from the bottom outlet 10b. To the latter distillation column 10 ', and in the latter distillation column 10', the middle fraction mainly composed of MTBE is extracted from the tower top outlet 10't, and the MTBE decomposition reactor 20 is connected via the line L4. The high boiling point compound can be extracted from the bottom outlet 10′b through the line L3.
In this case, the additional distillation column 10 ′ corresponds to an additional processing apparatus provided between the bottom outlet 10b of the MTBE distillation column 10 and the inlet 20i of the MTBE decomposition reactor 20, and in this case, the MTBE decomposition is also performed. The inlet 20i of the reactor 20 is connected to the bottom outlet 10b of the MTBE distillation column 10 through a subsequent distillation column 10 ′.

  In the first embodiment, the second extractor is a stream (F2B (F2)) in which methanol in the stream (F2A (F2)) discharged from the MTBE cracking reactor 20 is partially removed by the decomposition product distillation column 30. In the second embodiment, the stream (F2) discharged from the MTBE cracking reactor 20 is fed to the second extractor 40 as it is, and the oil phase of the second extractor 40 is supplied to the cracked product distillation column 30. Supply. However, the present invention can be implemented without providing the decomposition product distillation column 30.

  Moreover, the decomposition product distillation column 30 can be provided with a reflux portion that condenses the gas discharged from the uppermost stage again and circulates it to the distillation column. Moreover, the methanol distillation column 50 and the decomposition product distillation column 30 can be provided with a reboiler that heats the liquid discharged from the lowermost stage and returns it to the distillation column again. The distillation column is preferably a shelf type having a plurality of trays, but may be a packed column.

  In the said embodiment, although the tower type extractor is illustrated as the 2nd extractor 40 and the 1st extractor 60, it is not limited to this. As the tower-type extractor, for example, an extractor such as a spray tower type, a rotating disk tower type and a perforated plate type can be suitably used, and as an extractor other than the tower type, for example, a mixer-settler type or the like There are tank-type extractors.

  5 ... MTBE synthesis reactor, 10 ... MTBE distillation column, 20 ... MTBE decomposition reactor, 30 ... decomposition distillation column, 40 ... second extractor, 50 ... methanol distillation column, 55 ... tank, 60 ... first extractor , 100, 200... Isobutylene production apparatus, 300... MTBE production apparatus.

Claims (15)

An MTBE synthesis reactor having an inlet to which an MTBE raw material containing methanol is supplied and an outlet for discharging a reaction product;
An MTBE distillation column having an inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet;
An inlet connected to the top outlet of the MTBE distillation column; a water inlet to which water is supplied; an aqueous phase outlet for discharging an aqueous phase containing methanol; and an oil phase outlet for discharging an oil phase. A first extractor,
A methanol distillation column having an inlet connected to the aqueous phase outlet of the first extractor, a tower top outlet, and a tower bottom outlet; and
An MTBE manufacturing apparatus comprising at least one of the following lines (A) and (B):
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column and the first extractor.
Line (B) for connecting the MTBE synthesis reactor and the first extractor without passing through the MTBE distillation column The MTBE synthesis reactor has a plurality of unit reactors connected in series,
The line (A) connects the line between the unit reactors and the methanol distillation column,
The apparatus according to claim 1, wherein the line (B) connects a line between the unit reactors and the first extractor. An MTBE synthesis reactor having an inlet to which the MTBE raw material is supplied and an outlet for discharging the reaction product;
An inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet, or an inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet And an MTBE distillation column having a side outlet,
An MTBE decomposition reactor having an inlet connected to the bottom outlet or the side outlet of the MTBE distillation column, and an outlet for discharging an MTBE decomposition product containing isobutylene and methanol;
A cracked product distillation column having an inlet connected to an outlet of the MTBE cracking reactor, a tower top outlet, and a tower bottom outlet;
A methanol distillation tower having an inlet connected to the bottom outlet of the decomposition product distillation tower, a tower top outlet, and a tower bottom outlet; and
An apparatus for producing isobutylene, comprising at least one of the following lines (A) and (C):
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column, the MTBE decomposition reactor, and the decomposition product distillation column
Line (C) for connecting the MTBE synthesis reactor and the cracked product distillation column without passing through the MTBE distillation column and the MTBE decomposition reactor The MTBE synthesis reactor has a plurality of unit reactors connected in series,
The line (A) connects the line between the unit reactors and the methanol distillation column,
The said line (C) is an apparatus of Claim 3 which connects the line between the said unit reactors, and the said decomposition product distillation column. An MTBE synthesis reactor having an inlet to which the MTBE raw material is supplied and an outlet for discharging the reaction product;
An inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet, or an inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet And an MTBE distillation column having a side outlet,
An inlet connected to the top outlet of the MTBE distillation column; a water inlet to which water is supplied; an aqueous phase outlet for discharging an aqueous phase containing methanol; and an oil phase outlet for discharging an oil phase. A first extractor,
An MTBE decomposition reactor having an inlet connected to the bottom outlet or the side outlet of the MTBE distillation column, and an outlet for discharging an MTBE decomposition product containing isobutylene and methanol;
A cracked product distillation column having an inlet connected to an outlet of the MTBE cracking reactor, a tower top outlet, and a tower bottom outlet;
A methanol distillation column having an inlet connected to the bottom outlet of the decomposition product distillation column and / or the aqueous phase outlet of the first extractor, a top outlet, and a bottom outlet; and
An isobutylene production apparatus comprising at least one of the following lines (A) to (C):
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column, the first extractor, the MTBE decomposition reactor, and the decomposition product distillation column
Line (B) for connecting the MTBE synthesis reactor and the first extractor without passing through the MTBE distillation column
Line (C) for connecting the MTBE synthesis reactor and the cracked product distillation column without passing through the MTBE distillation column and the MTBE decomposition reactor The MTBE synthesis reactor has a plurality of unit reactors connected in series,
The line (A) connects the line between the unit reactors and the methanol distillation column,
The line (B) connects the line between the unit reactors and the first extractor,
The line (C) connects the line between the unit reactors and the decomposition product distillation column.
The apparatus according to claim 5. An MTBE synthesis reactor having an inlet to which the MTBE raw material is supplied and an outlet for discharging the reaction product;
An inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet, or an inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet And an MTBE distillation column having a side outlet,
An MTBE decomposition reactor having an inlet connected to the bottom outlet or the side outlet of the MTBE distillation column, and an outlet for discharging an MTBE decomposition product containing isobutylene and methanol;
A second inlet having an inlet connected to an outlet of the MTBE decomposition reactor, a water inlet to which water is supplied, an aqueous phase outlet for discharging an aqueous phase containing methanol, and an oil phase outlet for discharging an oil phase; Extractor,
A methanol distillation column having an inlet connected to the aqueous phase outlet of the second extractor, a tower top outlet, and a tower bottom outlet; and
An isobutylene production apparatus comprising at least one of the following lines (A) and (D):
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column, the MTBE decomposition reactor, and the second extractor.
Line (D) for connecting the MTBE synthesis reactor and the second extractor without passing through the MTBE distillation column and the MTBE decomposition reactor The MTBE synthesis reactor has a plurality of unit reactors connected in series,
The line (A) connects the line between the unit reactors and the methanol distillation column,
The line (D) connects the line between the unit reactors and the second extractor.
The apparatus according to claim 7. An MTBE synthesis reactor having an inlet to which the MTBE raw material is supplied and an outlet for discharging the reaction product;
An inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet, or an inlet connected to an outlet of the MTBE synthesis reactor, a tower top outlet, and a tower bottom outlet And an MTBE distillation column having a side outlet,
An inlet connected to the top outlet of the MTBE distillation column; a water inlet to which water is supplied; an aqueous phase outlet for discharging an aqueous phase containing methanol; and an oil phase outlet for discharging an oil phase. A first extractor,
An MTBE decomposition reactor having an inlet connected to the bottom outlet or the side outlet of the MTBE distillation column, and an outlet for discharging an MTBE decomposition product containing isobutylene and methanol;
A second inlet having an inlet connected to an outlet of the MTBE decomposition reactor, a water inlet to which water is supplied, an aqueous phase outlet for discharging an aqueous phase containing methanol, and an oil phase outlet for discharging an oil phase; Extractor,
A methanol distillation column having an inlet connected to the aqueous phase outlet of the first extractor and / or the aqueous phase outlet of the second extractor, a tower top outlet, and a tower bottom outlet; and
An isobutylene production apparatus comprising at least one of the following lines (A), (B), and (D):
Line (A) for connecting the MTBE synthesis reactor and the methanol distillation column without passing through the MTBE distillation column, the first extractor, the MTBE decomposition reactor, and the second extractor.
Line (B) for connecting the MTBE synthesis reactor and the first extractor without passing through the MTBE distillation column
Line (D) for connecting the MTBE synthesis reactor and the second extractor without passing through the MTBE distillation column and the MTBE decomposition reactor The MTBE synthesis reactor has a plurality of unit reactors connected in series,
The line (A) connects the line between the unit reactors and the methanol distillation column,
The line (B) connects the line between the unit reactors and the first extractor,
The line (D) connects the line between the unit reactors and the second extractor.
The apparatus according to claim 9. An MTBE manufacturing method using the MTBE manufacturing apparatus according to claim 1,
Supplying the hydrocarbon mixture containing isobutylene and methanol to the MTBE synthesis reactor containing the catalyst to produce MTBE;
Stopping the supply of the hydrocarbon mixture to the MTBE synthesis reactor;
Supplying methanol to the MTBE synthesis reactor after stopping the supply of the hydrocarbon mixture to obtain a purge stream (a) in which the hydrocarbon mixture and MTBE contained in the catalyst are eluted in methanol;
Sending the purge stream (a) to the methanol distillation column via the line (A) or to the first extractor via the line (B);
Further supplying water to the MTBE synthesis reactor to obtain a purge stream (b) in which methanol contained in the catalyst is eluted in water;
Sending the purge stream (b) to the methanol distillation column via the line (A) or to the first extractor via the line (B);
A method for manufacturing MTBE. An isobutylene production method using the isobutylene production apparatus according to claim 3 or 4,
Supplying the hydrocarbon mixture containing isobutylene and methanol to the MTBE synthesis reactor containing the catalyst to produce isobutylene;
Stopping the supply of the hydrocarbon mixture to the MTBE synthesis reactor;
Supplying methanol to the MTBE synthesis reactor after stopping the supply of the hydrocarbon mixture to obtain a purge stream (a) in which the hydrocarbon mixture and MTBE contained in the catalyst are eluted in methanol;
Sending the purge stream (a) to the methanol distillation column via the line (A) or to the cracked product distillation column via the line (C);
Further supplying water to the MTBE synthesis reactor to obtain a purge stream (b) in which methanol contained in the catalyst is eluted in water;
Sending the purge stream (b) to the methanol distillation column via the line (A) or to the cracked product distillation column via the line (C);
A process for producing isobutylene. A method for producing isobutylene using the isobutylene production apparatus according to claim 5,
Supplying the hydrocarbon mixture containing isobutylene and methanol to the MTBE synthesis reactor containing the catalyst to produce isobutylene;
Stopping the supply of the hydrocarbon mixture to the MTBE synthesis reactor;
Supplying methanol to the MTBE synthesis reactor after stopping the supply of the hydrocarbon mixture to obtain a purge stream (a) in which the hydrocarbon mixture and MTBE contained in the catalyst are eluted in methanol;
The purge stream (a) is sent to the methanol distillation column via the line (A), sent to the first extractor via the line (B), or the line via the line (C). Sending to the decomposition product distillation tower;
Further supplying water to the MTBE synthesis reactor to obtain a purge stream (b) in which methanol contained in the catalyst is eluted in water;
The purge stream (b) is sent to the methanol distillation column via the line (A), sent to the first extractor via the line (B), or the line via the line (C). And a step of sending to a decomposition product distillation column. A method for producing isobutylene using the isobutylene production apparatus according to claim 7 or 8,
Supplying the hydrocarbon mixture containing isobutylene and methanol to the MTBE synthesis reactor containing the catalyst to produce isobutylene;
Stopping the supply of the hydrocarbon mixture to the MTBE synthesis reactor;
Supplying methanol to the MTBE synthesis reactor after stopping the supply of the hydrocarbon mixture to obtain a purge stream (a) in which the hydrocarbon mixture and MTBE contained in the catalyst are eluted in methanol;
Sending the purge stream (a) to the methanol distillation column via the line (A) or to the second extractor via the line (D);
Further supplying water to the MTBE synthesis reactor to obtain a purge stream (b) in which methanol contained in the catalyst is eluted in water;
Sending the purge stream (b) to the methanol distillation column via the line (A) or to the second extractor via the line (D);
A process for producing isobutylene. A method for producing isobutylene using the isobutylene production apparatus according to claim 9 or 10,
Supplying the hydrocarbon mixture containing isobutylene and methanol to the MTBE synthesis reactor containing the catalyst to produce isobutylene;
Stopping the supply of the hydrocarbon mixture to the MTBE synthesis reactor;
Supplying methanol to the MTBE synthesis reactor after stopping the supply of the hydrocarbon mixture to obtain a purge stream (a) in which the hydrocarbon mixture and MTBE contained in the catalyst are eluted in methanol;
The purge stream (a) is sent to the methanol distillation column via the line (A), sent to the first extractor via the line (B), or the line via the line (D). Sending to a second extractor;
Further supplying water to the MTBE synthesis reactor to obtain a purge stream (b) in which methanol contained in the catalyst is eluted in water;
The purge stream (b) is sent to the methanol distillation column via the line (A), sent to the first extractor via the line (B), or the line via the line (D). And a step of sending to the second extractor.

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