KR101435230B1 - Process for production of propylene - Google Patents

Abstract

In the process for producing propylene by reacting at least one of olefins having 4 or more carbon atoms with methanol and dimethyl ether in the presence of a catalyst, propylene is produced at a high yield while suppressing deterioration of the catalyst by using a small amount of raw material.

Description

PROCESS FOR PRODUCTION OF PROPYLENE [0002]

The present invention relates to a process for producing propylene from a raw material mixture containing an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether.

As a method for producing propylene, steam cracking of naphtha and ethane and flow catalytic cracking of reduced pressure light oil have been conventionally practiced. Recently, a metathesis reaction using ethylene and 2-butene as raw materials, an olefin having 4 or more carbon atoms Contact cracking, and an MTO process using at least one of methanol and dimethyl ether as raw materials. On the other hand, there is also known a process for producing a lower olefin using an oxygen-containing compound such as an olefin having 4 or more carbon atoms and methanol as a raw material (Patent Document 1).

Patent Document 1: U.S. Patent No. 6888038

DISCLOSURE OF INVENTION

Problems to be solved by the invention

Conventionally, many proposals have been made for the production of propylene, and most of them have been disclosed for reactions and refiners. As for the method using oxygen-containing compounds such as olefins having 4 or more carbon atoms and methanol, Although its own proposal has been made, there has been no proposal for a process involving a purification system on the downstream side (downstream side) of the reactor.

Therefore, it is a first object of the present invention to provide a novel and economical process for producing propylene by reacting at least one of olefins having 4 or more carbon atoms with methanol and dimethyl ether.

On the other hand, in the steam cracking, which is currently the mainstream of the production method of ethylene or propylene, the ratio of ethylene to propylene to be produced can not be greatly changed. However, by integrating the process of the present invention with steam cracking, the ratio of ethylene to propylene can be remarkably changed. In addition, by integrating these two processes, it becomes possible to effectively utilize the fluid that is unnecessary in the processes of each other, and therefore, a remarkably efficient process construction can be expected by the synergistic effect.

Therefore, it is a second object of the present invention to provide a new and economical process which integrates the present process with steam cracking.

Means for solving the problem

The inventors of the present invention have studied the reaction of reacting olefins having 4 or more carbon atoms with at least one of methanol and dimethyl ether to obtain propylene. As a result, the following findings were obtained.

If the amount of olefin consumed by the reaction is excessively large, the by-product of undesirable compounds such as aromatic compounds and paraffins becomes remarkable. On the other hand, if the amount of the olefin consumed is too small, the yield of propylene becomes excessively low. Propylene can be obtained at a high selectivity and at a high yield by appropriately setting reaction conditions such as temperature, pressure, partial pressure and space velocity, and controlling the amount of olefin consumed to a certain specific range. When the reaction is carried out under such conditions, it is preferable that the compounds are recycled to the reactor in that the reactor outlet fluid contains a large amount of olefins having 4 or more carbon atoms which can be used as the reaction raw material.

On the other hand, in the reaction of at least one of the olefins having 4 or more carbon atoms with methanol and dimethyl ether, an aromatic compound or paraffin is also produced in a very small amount and contained in the reactor outlet fluid. Particularly, when a raw material containing paraffin as the olefin raw material having 4 or more carbon atoms is used, the paraffin concentration in the reactor outlet fluid increases. Since paraffins rarely react in the reactor, when recycled to the reactor together with olefins having 4 or more carbon atoms, paraffins are concentrated and accumulated in the system. For this reason, it is preferable to take out a part of the fluid containing paraffins from the system. In this case, it is preferable that the fluid to be extracted is a fluid having a composition that can be effectively used.

When aromatic compounds are present in a recycled olefin fluid having a carbon number of 4 or more at a specific concentration or more, the reaction between the aromatic compound and the olefin having 4 or more carbon atoms and the reaction of at least one of the aromatic compound with methanol and dimethyl ether become remarkable, At least one of olefins, methanol, and dimethyl ether of 4 or more is unnecessarily consumed.

Further, when the aromatic compound is supplied to the reactor, the compound produced by the reaction with the olefin having 4 or more carbon atoms clogs the pores of the catalyst, thereby accelerating the deterioration of the catalyst. Therefore, It is preferable to withdraw from a system and lower the concentration of aromatic compounds in the fluid recycled to the reactor. Even in this case, it is preferable that the fluid to be ejected is a fluid having a composition that can be effectively utilized.

As described above, the present inventors have found various problems in a process for producing propylene using at least one of an olefin having 4 or more carbon atoms and methanol and dimethyl ether as raw materials, and by constructing a process capable of solving the problems , It has been found that propylene can be produced at a high yield while suppressing deterioration of the catalyst by using a small amount of raw material.

In addition, it is possible to effectively use a fluid having a low value by supplying the fluid ejected from the present process to the steam cracking and supplying the fluid in the steam cracking to the present process, thereby realizing a remarkably efficient process I found out.

The present invention has been achieved on the basis of such findings, and the following will be given.

[1] A process for producing propylene by contacting an olefin having 4 or more carbon atoms and a raw material containing at least one of methanol and dimethyl ether in the presence of a catalyst in a reactor to produce propylene, wherein in the reactor outlet gas (reactor outlet gas) At least part of the aromatic compound contained, together with the extraction,

Wherein at least a part of the olefins having 4 or more carbon atoms contained in the reactor outlet gas (reactor outlet gas) is brought into contact with the catalyst again in the reactor.

[2] The process for producing propylene as described in [1], wherein the olefin raw material having 4 or more carbon atoms contains paraffins having 4 or more carbon atoms.

[3] The process for producing propylene as described in [2], wherein the paraffins contain at least one of normal butane and isobutane.

[4] The production method of propylene according to any one of [1] to [3], wherein the feedstock fed to the reactor contains butadiene.

[5] The method according to any one of [1] to [4], wherein the total amount of aromatic compounds contained in all the raw materials supplied to the reactor is less than 0.05 in terms of molar ratio with respect to the total amount of olefins having 4 or more carbon atoms ≪ / RTI >

[6] The method according to any one of [1] to [5], wherein the amount of the olefin having 4 or more carbon atoms supplied to the reactor is 2 times the number of moles of methanol fed to the reactor and the number of moles of dimethyl ether, Wherein the molar ratio is 0.2 or more and 10 or less.

[7] The method according to any one of [1] to [6], wherein the total concentration (substrate concentration) of the olefin having 4 or more carbon atoms and methanol and dimethyl ether contained in the entire raw material supplied to the reactor is 20% by volume or more and 80% By weight based on the total amount of propylene.

(8) A process for producing propylene by contacting an olefin having 4 or more carbon atoms and a raw material containing at least one of methanol and dimethyl ether in a reactor in the presence of a catalyst, (3A). ≪ / RTI >

Process (1): An olefin feedstock having a carbon number of 4 or more, a recycled hydrocarbon fluid (D) recycled from the process (3A), and at least one of methanol and dimethyl ether are fed into the reactor, and the molar flow rate of olefins having 4 or more carbon atoms Is brought into contact with the catalyst under reaction conditions of 20% or more and less than 90% with respect to the molar flow rate of the olefin at the inlet of the reactor, and a gas containing propylene and other olefins, paraffins, aromatic compounds, and water Reactor outlet gas)

Step (2): a step of separating the reactor outlet gas from the above-mentioned step (1) into a fluid rich in hydrocarbons having 3 or less carbon atoms, a fluid (A) rich in hydrocarbons having 4 or more carbon atoms and a fluid rich in water

Step (3A): At least part of the fluid (C) of the fluid (A) in the step (2) is mixed with the fluid (D) whose aromatic compound concentration is lower than the fluid (C) Separating the fluid (E) into a fluid (E) lower than the fluid (C), recycling the fluid (D) to the reactor, and withdrawing the fluid

(9) A process for producing propylene by contacting an olefin having 4 or more carbon atoms and a raw material containing at least one of methanol and dimethyl ether in the presence of a catalyst in a reactor to produce propylene, wherein the following steps (1), (3A). ≪ / RTI >

Process (1): An olefin feedstock having a carbon number of 4 or more, a recycled hydrocarbon fluid (D) recycled from the process (3A), and at least one of methanol and dimethyl ether are fed into the reactor, and the molar flow rate of olefins having 4 or more carbon atoms Is brought into contact with the catalyst under reaction conditions of 20% or more and less than 90% with respect to the molar flow rate of the olefin at the inlet of the reactor, and a gas containing propylene and other olefins, paraffins, aromatic compounds, and water Reactor outlet gas)

Step (2): a step of separating the reactor outlet gas from the above-mentioned step (1) into a fluid rich in hydrocarbons having 3 or less carbon atoms, a fluid (A) rich in hydrocarbons having 4 or more carbon atoms and a fluid rich in water

Step (3A): A part (B) of the fluid (A) in the step (2) is withdrawn from the process and the remaining fluid (C) ) And a hydrocarbon having a carbon number of 4 are separated into a fluid (E) lower than the fluid (C), the fluid (D) is recycled to the reactor and the fluid

[10] The olefin raw material according to [8] or [9], wherein the reactor comprises at least two reactors connected in series and fed to the reactor; At least one of methanol and dimethyl ether; Then, at least one of the recycled hydrocarbons-containing fluid (D) is divided and supplied to the first-stage reaction section and the second-stage and subsequent reaction sections.

[11] The method for producing propylene according to any one of [8] to [10], wherein the fluid (B) is supplied to steam cracking and used as a cracker raw material.

[12] The method for producing propylene according to [11], wherein at least a part of the fluid (B) is brought into contact with a hydrogenation catalyst and then supplied to steam cracking.

[13] A process for producing propylene as described in any one of [8] to [12], wherein the total concentration of aromatic compounds contained in the fluid (B) is less than 5.0% by volume.

[14] The method for producing propylene as described in any one of [8] to [13], wherein the fluid (E) is mixed with cracked gasoline fractions of steam cracking.

[15] The method for producing propylene as described in any one of [8] to [14], wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (E) is less than 5% by weight.

[16] The method of any one of [8] to [15], wherein the flow rate of the fluid (B) and the fluid (E) is controlled so that the total amount of the olefins, And the total concentration of dimethyl ether (substrate concentration) is controlled to be not less than 20% by volume and not more than 80% by volume.

(17) A process for producing propylene by contacting an olefin having 4 or more carbon atoms with a mixture containing at least one of methanol and dimethyl ether in the presence of a catalyst in a reactor to produce propylene, (3B). ≪ / RTI >

At least one of an olefin raw material having a carbon number of 4 or more, a recycled hydrocarbon fluid (I) recycled from the step (3B), and at least one of methanol and dimethyl ether is fed to the reactor, and the molar flow rate of the olefin having 4 or more carbon atoms at the outlet of the reactor Is brought into contact with the catalyst under the reaction conditions of 20% or more and less than 90% with respect to the molar flow rate of the olefin at the inlet, and a gas containing propylene and other olefins, paraffins, aromatic compounds and water Gas)

Step (2): A step of separating the reactor outlet gas from the above-mentioned step (1) into a fluid rich in hydrocarbons having 3 or less carbon atoms, a fluid (A) rich in hydrocarbons having 4 or more carbon atoms and a fluid rich in water

Step (3B): The fluid (A) in the above step (2) is mixed with the fluid (G) having the aromatic compound concentration lower than the fluid (A) and the fluid (F) , And at least part (I) of the fluid (G) is recycled to the reactor and the remaining fluid (H) is withdrawn from the process.

(18) A process for producing propylene by contacting an olefin having 4 or more carbon atoms with a mixture containing at least one of methanol and dimethyl ether in a reactor in the presence of a catalyst, (3B). ≪ / RTI >

At least one of an olefin raw material having a carbon number of 4 or more, a recycled hydrocarbon fluid (I) recycled from the step (3B), and at least one of methanol and dimethyl ether is fed to the reactor, and the molar flow rate of the olefin having 4 or more carbon atoms at the outlet of the reactor Is brought into contact with the catalyst under the reaction conditions of 20% or more and less than 90% with respect to the molar flow rate of the olefin at the inlet, and a gas containing propylene and other olefins, paraffins, aromatic compounds and water Gas)

Step (2): A step of separating the reactor outlet gas from the above-mentioned step (1) into a fluid rich in hydrocarbons having 3 or less carbon atoms, a fluid (A) rich in hydrocarbons having 4 or more carbon atoms and a fluid rich in water

Step (3B): The fluid (A) in the above step (2) is mixed with the fluid (G) having the aromatic compound concentration lower than the fluid (A) and the fluid (F) , Recycling the part (I) of the fluid (G) to the reactor and ejecting the remaining fluid (H) from the process, with the fluid (F)

[19] The olefin raw material according to [17] or [18], wherein the reactor is composed of at least two reactors connected in series and fed to the reactor; At least one of methanol and dimethyl ether; Then, at least one of the recycled hydrocarbons-containing fluid (I) is divided into a first reaction zone and a second reaction zone.

[20] A process for producing propylene according to any one of [17] to [19], wherein the fluid (H) is supplied to steam cracking and used as a cracker raw material.

[21] The method for producing propylene according to [20], wherein at least a part of the fluid (H) is brought into contact with a hydrogenation catalyst and then supplied to steam cracking.

[22] The production method of propylene according to any one of [17] to [21], wherein the total concentration of aromatic compounds contained in the fluid (H) is less than 5.0% by volume.

[23] A process for producing propylene as described in any one of [17] to [22], wherein the fluid (F) is mixed with cracked gasoline fractions of steam cracking.

[24] The production method of propylene according to any one of [17] to [23], wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (F) is less than 5% by weight.

[25] The method of any one of [17] to [24], wherein the flow rate of the fluid (F) and the fluid (H) is controlled so that the total amount of the olefins, And the total concentration of the ether (substrate concentration) is controlled to be not less than 20% by volume and not more than 80% by volume.

[26] The method according to any one of [8] to [25], wherein the step (2) comprises condensation removal of water from the reactor outlet gas by cooling and compression steps, Separating the fluid into a fluid enriched with hydrocarbons having 3 or more carbon atoms and separating the fluid rich in hydrocarbons having 3 or more carbon atoms into a fluid enriched with a hydrocarbon having 3 carbon atoms and a hydrocarbon enriched with 4 or more carbon atoms by distillation By weight of propylene.

[27] The method according to any one of [8] to [25], wherein the step (2) comprises condensation removal of water from the reactor outlet gas by cooling and compression steps, Separating the fluid into a fluid rich in hydrocarbons having 4 or more carbon atoms and separating the fluid rich in hydrocarbons having 3 or less carbon atoms into a fluid rich in hydrocarbon having 2 or less carbon atoms and a fluid rich in hydrocarbon having 3 carbon atoms by distillation ≪ / RTI >

[28] The method for producing a hydrocarbon-containing gas according to any one of [8] to [25], wherein the step (2) comprises condensation removal of water from the reactor outlet gas by cooling and compression processes, A fluid containing a hydrocarbon having 3 carbon atoms and a fluid enriched with hydrocarbons having 3 or more carbon atoms is separated and a fluid enriched with the hydrocarbon having 3 or more carbon atoms is separated by a distillation into a fluid enriched with a hydrocarbon having 3 carbon atoms and a hydrocarbon enriched with a hydrocarbon having 4 or more carbon atoms By weight of propylene.

[29] The method according to any one of [8] to [25], wherein the step (2) comprises condensation removal of water from the reactor outlet gas by cooling and compression steps, A fluid rich in hydrocarbons having 3 or less carbon atoms is separated into a fluid containing a hydrocarbon having 2 or less carbon atoms and a hydrocarbon having 3 carbon atoms and a hydrocarbon rich in carbon atoms having 3 carbon atoms by distillation And separating the propylene from the propylene.

[30] A process for producing propylene as described in any one of [8] to [29], wherein the olefin raw material having 4 or more carbon atoms contains paraffins having 4 or more carbon atoms.

[31] The process for producing propylene as described in [30], wherein the paraffins contain at least one of normal butane and isobutane.

[32] A process for producing propylene according to any one of [8] to [31], wherein the feedstock fed to the reactor contains butadiene.

[33] The method for producing a catalyst according to any one of [8] to [32], wherein the total amount of aromatic compounds contained in all the raw materials supplied to the reactor is less than 0.05 in terms of molar ratio with respect to the total amount of olefins having 4 or more carbon atoms ≪ / RTI >

[34] A process for producing a polymer according to any one of [8] to [33], wherein the amount of the olefin having 4 or more carbon atoms supplied to the reactor is 2 times the number of moles of methanol supplied to the reactor and the number of moles of dimethyl ether , And a molar ratio of 0.2 or more to 10 or less.

[35] A process for producing propylene as described in any one of [8] to [34], wherein the olefin raw material having 4 or more carbon atoms supplied to the reactor contains a hydrocarbon fluid having 4 carbon atoms obtained by steam cracking.

(36) A process for producing propylene by contacting a mixture containing an olefin having 4 or more carbon atoms with a mixture containing at least one of methanol and dimethyl ether in the presence of a catalyst in a reactor to produce propylene by the following steps (1C), (2C) (3C) and (4C). ≪ / RTI >

Process (1C): An olefin feedstock having a carbon number of 4 or more, a recycled hydrocarbon fluid (Q) recycled from the process (4C), and at least one of methanol and dimethyl ether are fed to the reactor, and the molar flow rate of the olefin having 4 or more carbon atoms Is contacted with the catalyst under reaction conditions of 20% or more and less than 90% with respect to the molar flow rate of the olefin at the inlet of the reactor, and a gas containing propylene and other olefins, paraffins, aromatic compounds and water Outlet gas)

Step (2C): The reactor outlet gas from the step (1C) is cooled and separated into a gas fluid (L), a liquid fluid (M) rich in hydrocarbons having 4 or more carbon atoms and containing an aromatic compound and a water- Process

Step (3C): A step of separating the gas fluid (L) in the step (2C) into a fluid rich in hydrocarbons having 3 or less carbon atoms and a fluid (N) rich in hydrocarbons having 4 or more carbon atoms

Step (4C): a step of recycling at least part of the fluid (Q) of the fluid (N) to the reactor

(37) A process for producing propylene by contacting a mixture containing an olefin having 4 or more carbon atoms with a mixture containing at least one of methanol and dimethyl ether in the presence of a catalyst in a reactor to obtain propylene by the following steps (1C), (2C) (3C) and (4C). ≪ / RTI >

Process (1C): An olefin feedstock having a carbon number of 4 or more, a recycled hydrocarbon fluid (Q) recycled from the process (4C), and at least one of methanol and dimethyl ether are fed to the reactor, and the molar flow rate of the olefin having 4 or more carbon atoms Is brought into contact with the catalyst under reaction conditions of 20% or more and less than 90% with respect to the molar flow rate of the olefin at the inlet of the reactor, and a gas containing propylene and other olefins, paraffins, aromatic compounds and water Outlet gas)

Process (2C): The reactor outlet gas from the process (1C) is cooled and the gas fluid (K) after cooling is compressed to obtain a gas fluid (L), a liquid containing an aromatic compound rich in hydrocarbons having 4 or more carbon atoms Process for separating into fluid (M) and water-rich fluid

Step (3C): A step of separating the gas fluid (L) in the step (2C) into a fluid rich in hydrocarbons having 3 or less carbon atoms and a fluid (N) rich in hydrocarbons having 4 or more carbon atoms

Step (4C): a step of withdrawing part (P) of the fluid (N) from the process and recycling the remaining fluid (Q) to the reactor.

(38) The method according to any one of the above (38) to (36), wherein the liquid fluid (M) is subjected to distillation so that the concentration of the liquid (S) lower than the molecular weight (M).

[39] The method for producing a polymer electrolyte fuel cell according to the above item [38], wherein the fluid R is used as a distribution point of one or more fluids selected from the fluids K, L, M, P and Q And then recycling the propylene.

(40) The method according to any one of (36) to (39), wherein the gas fluid (L) is distilled from a fluid rich in hydrocarbons having 2 or less carbon atoms and a hydrocarbon rich in carbon atoms Separating a fluid rich in hydrocarbons having 3 or more carbon atoms into a fluid rich in hydrocarbon having 3 carbon atoms and a fluid rich in hydrocarbon having 4 or more carbon atoms by distillation. Way.

[41] The method of any one of the above items [36] to [39], wherein the step (3C) comprises distilling the gaseous fluid (L) into a fluid rich in hydrocarbons having 3 or less carbon atoms and a hydrocarbon rich in 4 or more carbon atoms (N), and further separating a fluid rich in hydrocarbons having 3 or less carbon atoms into a hydrocarbon-rich fluid having 2 or less carbon atoms and a hydrocarbon-rich fluid having 3 carbon atoms by distillation Propylene.

[42] The method of any one of the above items [36] to [39], wherein the step (3C) comprises distilling the gaseous fluid (L) into a fluid containing a hydrocarbon having 2 or less carbon atoms and a hydrocarbon having 3 carbon atoms, Separating the fluid rich in at least three or more hydrocarbons into a fluid rich in hydrocarbons having three or more carbon atoms and a fluid rich in hydrocarbons having at least three carbon atoms by distillation into a fluid rich in hydrocarbon having three carbon atoms and a fluid rich in hydrocarbon having four or more carbon atoms ≪ / RTI >

[43] The method according to any one of the items [36] to [39], wherein the step (3C) is a step in which the gas fluid (L) is distilled to obtain a hydrocarbon-rich fluid having 3 or less carbon atoms and a hydrocarbon- Separating the hydrocarbon-rich fluid having a carbon number of 3 or less into a fluid containing a hydrocarbon having a carbon number of 2 or less and a hydrocarbon containing 3 carbon atoms and a hydrocarbon-rich fluid having a carbon number of 3 by distillation ≪ / RTI >

[44] An olefin raw material according to any one of the items [36] to [43], wherein the reactor is composed of two or more reactors connected in series and fed to the reactor; At least one of methanol and dimethyl ether; Then, at least one of the recycled hydrocarbons-containing fluid is divided and supplied to the first-stage reaction section and the second-stage and subsequent reaction sections.

[45] A process for producing propylene as described in any one of [36] to [44], wherein the olefin raw material having 4 or more carbon atoms contains paraffins having 4 or more carbon atoms.

[46] The process for producing propylene as described in [45], wherein the paraffins contain at least one of normal butane and isobutane.

[47] A process for producing propylene as described in any one of [36] to [46], wherein the feedstock fed to the reactor contains butadiene.

[48] A process for producing a catalyst for olefin polymerization according to any one of [36] to [47], wherein the total amount of aromatic compounds contained in all the raw materials fed to the reactor is in a molar ratio of 0.05 to the total amount of olefins having 4 or more carbon atoms ≪ / RTI > by weight.

[49] A process for producing propylene as described in any one of [36] to [48], wherein at least one of the fluid (M) and the fluid (P) is supplied to steam cracking and used as a cracker raw material Way.

[50] The method for producing propylene according to [49], wherein at least a part of at least one of the fluid (M) and the fluid (P) is contacted with a hydrogenation catalyst and then supplied to steam cracking.

[51] The propylene polymer according to any one of [36] to [50], wherein the total concentration of aromatic compounds contained in at least one of the fluid (M) and the fluid (P) is less than 5.0% Gt;

[52] A method for producing propylene according to any one of [36] to [51], wherein the fluid (M) is mixed with decomposed gasoline oil of steam cracking.

[53] A process for producing propylene as described in any one of [36] to [52], wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (M) is less than 5% by weight.

[54] The method of any one of items [36] to [53], wherein the flow rate of the fluid (M) and the fluid (P) And the dimethyl ether (concentration of the substrate) is controlled to 20 vol% or more and 80 vol% or less.

[55] A process for producing propylene according to any one of [38] to [54], wherein the fluid (R) is supplied to steam cracking and used as a cracker raw material.

[56] The method for producing propylene according to [55], wherein at least a part of the fluid (R) is contacted with a hydrogenation catalyst and then supplied to steam cracking.

[57] A process for producing propylene according to any one of [38] to [56], wherein the total concentration of aromatic compounds contained in the fluid (R) is less than 5.0% by volume.

[58] A process for producing propylene as described in any one of [38] to [57], wherein the fluid (S) is mixed with cracked gasoline fractions of steam cracking.

[59] A method for producing propylene according to any one of [38] to [58], wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (S) is less than 5% by weight.

[60] The method of any one of items [38] to [59], wherein the flow rate of the fluid (P), the fluid (R), and the fluid (S) And the total concentration of the olefin, the methanol and the dimethyl ether (substrate concentration) is controlled to be not less than 20% by volume and not more than 80% by volume.

[61] The method of any one of [38] to [60], wherein the fluid (R) is any one selected from the fluids (K), (L), (N), (P) (Substrate concentration) of the olefin having 4 or more carbon atoms and the methanol and the dimethyl ether contained in the entire raw material supplied to the reactor by controlling the conveying point and the flow rate of the fluid R when returning to the point of the two or more fluids, Is controlled to be not less than 20% by volume and not more than 80% by volume.

[62] The polymer electrolyte fuel cell according to any one of the items [36] to [61], wherein the amount of the olefin having 4 or more carbon atoms supplied to the reactor is twice the number of moles of methanol fed to the reactor and the number of moles of dimethyl ether , And a molar ratio of 0.2 or more to 10 or less.

[63] A process for producing propylene according to any one of [36] to [62], wherein the olefin raw material having 4 or more carbon atoms supplied to the reactor contains a hydrocarbon fluid having 4 carbon atoms obtained by steam cracking.

Effects of the Invention

According to the present invention, there is provided a process for producing propylene by reacting at least one of an olefin feedstock having a carbon number of 4 or more with methanol and dimethyl ether in the presence of a catalyst, wherein the feedstock is highly used, Can be prepared.

In addition, the method of the present invention can be integrated with steam cracking to provide an economical process.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a systematic diagram showing an embodiment of the process for producing propylene of the present invention. Fig.

2 is a flow diagram showing another example of an embodiment of the process for producing propylene of the present invention.

3 is a flow diagram showing another example of the embodiment of the process for producing propylene of the present invention.

Explanation of symbols

10 Reactor

20 First separation and purification system

30A, 30B Second separation and purification system

13 Reactor

23 compressor

33 knockout drum

43 oil water separator

53 1st separation and purification system

63 2nd separation and purification system

Carrying out the invention  Best form for

Hereinafter, exemplary embodiments for carrying out the present invention will be described concretely, but the present invention is not limited to the following embodiments unless it departs from the gist of the present invention.

A process for producing propylene according to the present invention is a process for producing propylene by contacting an olefin having 4 or more carbon atoms and a raw material containing at least one of methanol and dimethyl ether in the presence of a catalyst in a reactor to produce propylene, At least a part of the aromatic compound contained in the reactor is withdrawn and at least a part of the olefins having 4 or more carbon atoms contained in the reactor outlet gas are brought into contact with the catalyst again in the reactor.

(1), (2), (3A) or (1), (2), and (3B) as described above as the more specific first and second embodiments, (1C), (2C), (3C), and (4C) of the fourth step as described above. However, as far as the purpose of solving the problems of the present invention is concerned, Alternatively, there may be other processes before and after the four processes, and there may be other processes between the respective processes.

Means that the purity of the target substance is 50 mol% or more, preferably 70 mol% or more, more preferably 90 mol% or more, furthermore preferably 95 mol% or more. For example, " fluid (N) rich in hydrocarbons having 4 or more carbon atoms " means 50 mol% or more, preferably 70 mol% or more, more preferably 90 mol% Is a fluid containing 95 mol% or more.

[catalyst]

First, the catalyst used in the present invention will be explained.

The catalyst used in the reaction according to the present invention is not particularly limited as long as it is a solid phase having a Bronsted acid point, and conventionally known catalysts are used. For example, clay minerals such as kaolin; Clay minerals and the like impregnated and supported with an acid such as sulfuric acid or phosphoric acid; Acid form ion exchange resins; Zeolites; Aluminum phosphates; And a solid acid catalyst such as mesoporous silica alumina such as Al-MCM41.

Among these solid acid catalysts, those having a molecular sieve effect are preferred, and the acid strength is preferably not so high.

AEI, AET, AFI, AFO, AFS, AOI, AOI, AOI, AOI, AOI, AOI and AOI can be used as the structures of the zeolite or aluminum phosphate having molecular sieve effect, AST, ATN, BEA, CAN, CHA, EMT, ERI, EUO, FAU, FER, LEV, LTL, MAZ, MEL, MFI, MOR, MTT, MTW, MWW, OFF, PAU, RHO, STT, . MEL, MOR, MWW, FAU, BEA and CHA, and more preferably MFI, MEL, MOR, MWW and CHA are preferable, and catalysts having a framework density of 18.0 T / MOR, MWW, CHA, particularly preferably MFl, MEL, MWW and CHA.

Here, the framework density (unit T / n m 3) means the number of T atoms (atoms other than oxygen in atoms constituting the skeleton of zeolite) present per unit volume (1 n m 3) of zeolite, The value is determined by the structure of the zeolite.

The solid acid catalyst is more preferably a crystalline aluminosilicate having micropores having a pore diameter of 0.3 to 0.9 nm and a BET specific surface area of 200 to 700 m 2 / g and a pore volume of 0.1 to 0.5 g / Metal silicates or crystalline aluminum phosphates are preferred. Here, the pore diameter refers to a crystallographic free diameter of the channels defined by the International Zeolite Association (IZA), and when the shape of the pores (channels) is a true circular shape, When the shape is elliptical, it indicates short diameter.

In the aluminosilicate, the molar ratio of SiO ₂ / Al ₂ O ₃ is preferably 10 or more. If the molar ratio of SiO ₂ / Al ₂ O ₃ is too low, the durability of the catalyst is lowered. The upper limit of the molar ratio of SiO ₂ / Al ₂ O ₃ is usually 10000 or less. If the molar ratio of SiO ₂ / Al ₂ O ₃ is too high, the catalytic activity is lowered, which is not preferable. The molar ratio can be determined by a conventional method such as fluorescent X-ray or chemical analysis.

The aluminum content in the catalyst can be controlled by the feed amount of the raw material at the preparation of the catalyst, and Al can be reduced by steaming or the like after preparation. In addition, a part of Al may be substituted with another element such as boron or gallium, and it is particularly preferable to substitute with boron.

These catalysts may be used alone or in combination of two or more.

In the present invention, the catalytically active component as described above may be used in the reaction as it is, or it may be used in the reaction by assembling or molding using a substance or binder which is inert to the reaction, or by mixing them. Examples of the substance or binder inert to the reaction include alumina or alumina sol, silica, silica gel, quartz, and mixtures thereof.

The above-mentioned catalyst composition is the composition of only the catalytically active component which does not contain a substance inert to these reactions or a binder. However, when the catalyst according to the present invention contains a substance inert to these reactions, a binder, etc., the above-described catalytically active component and a substance or binder inert to these reactions are all referred to as catalysts, In the case of not containing a substance, a binder or the like, the catalytically active component alone is referred to as a catalyst.

The particle diameter of the catalytically active component used in the present invention varies depending on the conditions at the time of synthesis but is usually 0.01 to 500 m as an average particle diameter. If the particle diameter of the catalyst is too large, the surface area showing the catalytic activity becomes small. If the particle size is excessively small, the handling property becomes inferior, and neither case is preferable. This average particle diameter can be obtained by SEM observation or the like.

The method for preparing the catalyst used in the present invention is not particularly limited, and it can be generally prepared by a known method called hydrothermal synthesis. After the hydrothermal synthesis, the composition may be changed by ion exchange, dealumination treatment, impregnation, or the like.

The catalyst to be used in the present invention may be one having any of the above physical properties and / or composition and being prepared by any method.

[Feedstock]

Next, the olefins, methanol, and dimethyl ether having 4 or more carbon atoms as reaction raw materials in the present invention will be explained.

 ≪

The olefin having 4 or more carbon atoms used as a raw material for the reaction is not particularly limited. For example, a hydrogen / CO mixed gas obtained by gasification of coal from a petroleum feedstock (BB oil, C4 raffinate-1, C4 raffinate-2 etc.) produced by catalytic cracking or steam cracking or the like is used as a raw material Obtained by an oligomerization reaction containing a dimerization reaction of ethylene, a dehydrogenation method or an oxidative dehydrogenation method of a paraffin having 4 or more carbon atoms, a reaction product obtained by an MTO reaction Olefins having 4 or more carbon atoms, in particular 4 to 10 carbon atoms, obtained by various known methods such as those obtained by dehydration of an alcohol and those obtained by hydrogenation of a diene compound having 4 or more carbon atoms, In this case, compounds other than olefins having 4 or more carbon atoms resulting from each production method are arbitrarily mixed, And it may be used as may be used a purified olefin.

Among them, when an olefin raw material containing paraffins having 4 or more carbon atoms is used, since the paraffin serves as a diluting gas, the reaction temperature can be easily controlled, and the raw material containing paraffin can be obtained at low cost It is preferable because there are many cases. More preferably, it is an olefin raw material containing at least one of normal butane and isobutane.

These preferred raw materials include the above-mentioned BB oil fraction, C4 raffinate-1 and C4 raffinate-2. These raw materials usually contain butadiene. Since it is easy for the butadiene to be converted into an aromatic compound by the reaction, it is very important to withdraw at least a part of the produced aromatic compound without recycling it to the reactor as in the present invention. Further, since BB oil contains a large amount of butadiene, it is preferable to use a fluid having a reduced butadiene concentration brought into contact with a hydrogenation catalyst as a raw material.

 <Methanol, dimethyl ether>

The origin of the production of at least one of methanol and dimethyl ether used as a raw material for the reaction is not particularly limited. For example, it can be obtained by a hydrogenation reaction of hydrogen / CO mixed gas derived from coal and natural gas and by-products in the iron and steel industry, by a reforming reaction of alcohols derived from plants, Those obtained from organic materials such as recycled plastics and municipal wastes, and the like. At this time, any compound other than methanol and dimethyl ether resulting from each production method may be used as it is, or a purified product may be used.

[Reaction operation and conditions: Step (1) (1C) in the first to third embodiments]

Hereinafter, the operation and conditions of the propylene production reaction of the present invention using the above-described catalyst and reaction raw materials will be described.

 <Reactor>

The reaction of at least one of the olefins having 4 or more carbon atoms with methanol and dimethyl ether in the present invention is a gas phase reaction. The type of the gas phase reactor is not particularly limited, but is usually selected in a continuous fixed bed reactor or a fluidized bed reactor. Preferably a stationary phase reactor.

When the above-described catalyst is charged in the fixed bed reactor, particulate inert to the reaction such as quartz, alumina, silica, silica-alumina and the like may be mixed and charged with the catalyst in order to suppress the temperature distribution of the catalyst bed to be small. In this case, the amount of the granular material inert to the reaction of the quartz glass or the like is not particularly limited. It is preferable that the granular material has a particle diameter equivalent to that of the catalyst in terms of homogeneous mixing with the catalyst.

The reactor may be composed of two or more reactors connected in series. In this case, one reactor may be divided into a plurality of reaction chambers, or two or more reactors may be connected in series.

In the case where two or more reactors are connected in series, a heat exchanger may be disposed between the reactor and the reactor in order to remove the heat accompanying the reaction.

Further, for the purpose of dispersing heat, the reaction substrate (reaction raw material) may be divided and supplied. Preferably, at least one of methanol and dimethyl ether is divided into a first reaction zone (reactor or reaction chamber) and a second reaction zone (reactor or reaction chamber).

In the reaction conditions used in the present invention, the catalyst has less caulking and the catalyst deterioration is slower, but in the case of continuous operation for one year or more, it is necessary to carry out catalyst regeneration during operation.

For example, when a fixed bed reactor is selected, it is preferable to install at least two reactors at least in parallel and operate while switching between reaction and regeneration. In the form of a fixed bed reactor, a multi-tubular reactor or an adiabatic reactor is selected.

On the other hand, in the case of selecting a fluidized bed reactor, it is preferable to send the catalyst continuously to the regeneration tank and conduct the reaction while continuously returning the regenerated catalyst to the reactor in the regeneration tank.

Here, as the regeneration operation of the catalyst, there is a method of regenerating by treating the catalyst deteriorated by caulking with nitrogen gas containing oxygen or steam or the like. Regeneration operation in the fixed bed reactor is preferably carried out by removing volatile organic compounds adhering to the catalyst with nitrogen gas, burning off coke minutes with nitrogen gas containing low concentration of oxygen, And removing the molecular oxygen contained in the catalyst layer by treatment with a gas.

 &Lt; Concentration ratio of at least one of olefin, methanol and dimethyl ether fed to the reactor &

In the present invention, the amount of the olefin having 4 or more carbon atoms supplied to the reactor is 0.2 or more, preferably 0.5 or more, and 10 or less in terms of molar ratio to the sum of the number of moles of methanol fed to the reactor and twice the number of moles of dimethyl ether , Preferably 5 or less.

That is, Mc4 is 0.2 to 10 times, preferably 0.5 to 5 times as much as (Mm + 2 Mdm) when the feed molar amount of olefin having 4 or more carbon atoms is Mc4, the feed molar amount of methanol is Mm, and the feed molar amount of dimethyl ether is Mdm.

If the feed concentration ratio is too low or too high, the reaction becomes slow, which is undesirable. Particularly, if the feed concentration ratio is too low, the consumption of olefin in the raw material is decreased.

Here, the supply concentration ratio can be found by quantifying the composition of each fluid supplied to the reactor or the fluid after mixing by a general analytical method such as gas chromatography.

When at least one of olefins having 4 or more carbon atoms and methanol and dimethyl ether is fed to the reactor, they may be supplied separately or may be fed after a part or all of them are mixed.

 &Lt; Substrate concentration supplied to the reactor &

In the present invention, the total concentration (substrate concentration) of the olefin having 4 or more carbon atoms and methanol and dimethyl ether in the entire feedstock fed to the reactor is preferably 20% by volume or more and 80% by volume or less, more preferably 30% Not less than 70% by volume.

Here, the substrate concentration can be found by quantifying the composition of each fluid supplied to the reactor or the fluid after mixing by a general analytical method such as gas chromatography.

If the substrate concentration is too high, the production of aromatic compounds or paraffins becomes remarkable, and the selectivity of propylene tends to be lowered. On the other hand, if the substrate concentration is too low, the reaction rate becomes slow, so that a large amount of catalyst is required, and the purification cost of the product and the construction cost of the reaction equipment become large, which is not economical.

In the present invention, the reaction substrate is diluted with the diluting gas described below so as to have such a substrate concentration. In this case, as a method of controlling the substrate concentration, a method of controlling the flow rate of the fluid ejected from the process can be mentioned. That is, by changing the flow rate of the fluid discharged from the process, the flow rate of the dilution gas recycled to the reactor is changed, and the concentration of the substrate can be changed.

 <Impurity concentration in the gas supplied to the reactor>

In the present invention, there are cases where butadiene is contained in a hydrocarbon-containing fluid to be recycled and / or recycled in an olefin feedstock having not less than 4 carbon atoms. The concentration of butadiene in the entire feedstock fed to the reactor is preferably 2.0 vol% desirable. If the concentration of butadiene in the raw material is high, the production of an aromatic compound is increased and deterioration due to caulking of the catalyst is accelerated, which is not preferable.

Here, the butadiene concentration can be determined by quantifying the composition of each fluid supplied to the reactor or the fluid after mixing by a general analytical method such as gas chromatography.

As a method of lowering the concentration of butadiene in the raw material, there is a partial hydrogenation method in which the fluid is brought into contact with a hydrogenation catalyst to convert it to olefins.

The hydrocarbon-containing fluid to be recycled to the reactor may contain an aromatic compound. The total amount of the aromatic compounds contained in the entire feedstock fed to the reactor is preferably at least 4 carbon atoms Olefin is preferably less than 0.05 in a molar ratio with respect to the total amount of olefin. If the concentration of the aromatic compound in the raw material is high, the reaction of the aromatic compound with the olefin having 4 or more carbon atoms or the reaction between the aromatic compound and at least one of methanol and dimethyl ether becomes prominent in the reactor and the olefin, methanol and dimethyl ether Which is not preferable.

Further, when the aromatic compound is supplied to the reactor, the compound produced by the reaction with the olefin having 4 or more carbon atoms clogs the pores of the catalyst, thereby accelerating the deterioration of the catalyst. Therefore, It is preferable to withdraw from a system and lower the concentration of aromatic compounds in the fluid recycled to the reactor.

The ratio of the total amount of the aromatic compounds to the total amount of the olefins having 4 or more carbon atoms can be determined by quantifying the composition of each fluid supplied to the reactor or the fluid after mixing by a general analytical method such as gas chromatography.

As a method for lowering the concentration of an aromatic compound in a raw material, a separation method by distillation can be mentioned.

 <Dilution gas>

An inert gas such as paraffins, aromatics, steam, carbon dioxide, carbon monoxide, nitrogen, argon, helium and mixtures thereof is present in the reactor in addition to at least one of olefins having 4 or more carbon atoms and at least one of methanol and dimethyl ether . Among these diluent gases, paraffin or aromatic gas may be slightly reacted depending on the reaction conditions, but is defined as a diluent gas in that the amount of reaction is small.

As such a diluting gas, the impurities contained in the reaction raw material may be used as is, or a separately prepared diluting gas may be mixed with the reaction raw material.

The diluent gas may be mixed with the reaction raw material before being put into the reactor, or may be supplied to the reactor separately from the reaction raw material.

A preferred diluent gas is paraffins having 4 or more carbon atoms. More preferably at least one of normal butane and isobutane. These paraffins can use those contained in the olefin feedstock and control the reaction temperature easily because they are compounds having a relatively large heat capacity.

 <Space velocity>

Here, the space velocity is the flow rate of the olefin having 4 or more carbon atoms as the reaction raw material per weight of the catalyst (catalytically active component), and the weight of the catalyst means the inert component used for the assembly and the shaping of the catalyst or the catalytically active component . The flow rate is the flow rate (weight / hour) of the olefin having 4 or more carbon atoms.

The space velocity is preferably between 0.1Hr ^-1 500Hr to ^-1, and is between 1.0Hr ^{-1 -1} to 100Hr more preferred. If the space velocity is excessively high, the conversion rate of at least one of olefin, methanol and dimethyl ether as raw materials is low, and a sufficient propylene selectivity is not obtained. On the other hand, if the space velocity is too low, the amount of the catalyst required to obtain a constant production amount increases, the reactor becomes excessively large, and an undesired by-product such as an aromatic compound or paraffin is produced and the propylene selectivity is lowered.

 <Reaction temperature>

The lower limit of the reaction temperature is usually about 300 DEG C or higher, preferably 400 DEG C or higher as the gas temperature at the inlet of the reactor, and the upper limit of the reaction temperature is usually 700 DEG C or lower, preferably 600 DEG C or lower. When the reaction temperature is too low, the reaction rate is low, a large amount of unreacted starting material tends to remain, and the yield of propylene is also lowered. On the other hand, if the reaction temperature is excessively high, the yield of propylene is remarkably lowered.

 <Reaction Pressure>

The upper limit of the reaction pressure is usually 2 MPa (absolute pressure, the same applies hereinafter) or less, preferably 1 MPa or less, and more preferably 0.7 MPa or less. The lower limit of the reaction pressure is not particularly limited, but is usually 1 kPa or more, preferably 50 kPa or more. If the reaction pressure is excessively high, the amount of undesired by-products such as paraffins and aromatic compounds increases, and the yield of propylene tends to decrease. If the reaction pressure is too low, the reaction rate tends to be slowed down.

 &Lt; Consumption amount of raw material by reaction &

It is preferable that the sum of the molar flow rate of methanol at the outlet of the reactor and the molar flow rate of the dimethyl ether is less than 1% with respect to the sum of the molar flow rate of the methanol fed to the reactor and the molar flow rate of the dimethyl ether. , More preferably less than 0.1%.

When the consumption amount of methanol and dimethyl ether in the reactor is small and the amount of methanol or dimethyl ether at the outlet of the reactor is excessively increased, purification of the product olefin becomes difficult.

As a method of increasing the consumption of methanol and dimethyl ether, a method of raising the reaction temperature or lowering the space velocity can be mentioned.

In the present invention, the molar flow rate of the olefin having 4 or more carbon atoms at the outlet of the reactor is 20% or more and less than 90% with respect to the molar flow rate of the olefin having 4 or more carbon atoms supplied to the reactor. The molar flow rate ratio is preferably 20% or more and less than 70%, more preferably 25% or more and less than 60%. When the consumption amount of the olefin having 4 or more carbon atoms in the reactor is too small, unreacted olefin is increased and the flow rate of the fluid recycled to the reactor becomes too large. On the contrary, if the consumption amount is too large, undesirable compounds such as paraffin and aromatic compounds are produced as by-products, and the yield of propylene is lowered.

As a method of adjusting the consumption amount of the olefin having 4 or more carbon atoms in the reactor, a method of appropriately setting the reaction temperature and the space velocity can be mentioned.

The flow rate of methanol, dimethyl ether, and olefins having 4 or more carbon atoms fed to the reactor is determined by a general analytical method such as gas chromatography or the like, and the flow rate of each fluid The flow rate of methanol and dimethyl ether at the outlet of the reactor and the olefin having 4 or more carbon atoms can be determined by measuring the composition of the reactor outlet fluid by a general method such as gas chromatography and measuring or calculating the flow rate of the reactor outlet fluid have.

 &Lt; Reaction product >

As the reactor outlet gas (reactor effluent), a mixed gas containing propylene as a reaction product, an unreacted raw material, a by-product and a diluent is obtained. The concentration of propylene in the mixed gas is usually 5 to 95% by weight.

The unreacted raw material is usually an olefin having 4 or more carbon atoms. Depending on the reaction conditions, it is preferable to carry out the reaction under the reaction conditions in which at least one of methanol and dimethyl ether is contained, but at least one of methanol and dimethyl ether is not left. Thereby, separation of the reaction product and the unreacted raw material becomes easy.

Examples of the by-products include ethylene, olefins having 4 or more carbon atoms, paraffins, aromatic compounds, and water.

[Separation Process]

The separation process in the first and second embodiments

 &Lt; Separation of hydrocarbons having 3 or less carbon atoms and water: Step (2) >

The reactor outlet gas is separated into a fluid rich in hydrocarbons having 3 or less carbon atoms, a fluid rich in hydrocarbons having 4 or more carbon atoms and a fluid rich in water by a general separation process such as cooling, compression and distillation.

As a first mode of the above general separation process, the water is condensed and removed by a cooling and compression process, and then separated into a fluid rich in hydrocarbons having 2 or less carbon atoms and a fluid rich in hydrocarbons having 3 or more carbon atoms by distillation and a hydrocarbon having 3 or more carbon atoms A method including a step of separating a rich fluid into a fluid rich in hydrocarbon having 3 carbon atoms and a fluid rich in hydrocarbon having 4 or more carbon atoms by distillation is applied.

As a second mode of the general separation process, the water is condensed and removed by a cooling and compression process, and then separated into a fluid rich in hydrocarbons having 3 or less carbon atoms and a hydrocarbon (A) rich in hydrocarbons having 4 or more carbon atoms by distillation, A method including a step of separating a fluid rich in hydrocarbon into a fluid rich in hydrocarbon having 2 or less carbon atoms and a fluid rich in hydrocarbon having 3 carbon atoms by distillation is applied.

As a third mode of the general separation process, water is condensed and removed by a cooling and compression process, and then separated into a fluid containing a hydrocarbon having 2 or less carbon atoms and a hydrocarbon having 3 or more carbon atoms and a hydrocarbon-rich fluid having 3 or more carbon atoms by distillation, A method including a step of separating a fluid rich in three or more hydrocarbons into a fluid rich in hydrocarbon having 3 carbon atoms and a fluid A rich in hydrocarbon and having 4 or more carbon atoms by distillation is applied.

As a fourth mode of the general separation process, the water is condensed and removed by a cooling and compression process, and then separated into a fluid rich in hydrocarbons having 3 or less carbon atoms and a fluid (A) rich in hydrocarbons having 4 or more carbon atoms by distillation, A process comprising separating a hydrocarbon-rich fluid into a fluid containing a hydrocarbon having 2 or less carbon atoms and a hydrocarbon containing 3 carbon atoms and a hydrocarbon-rich fluid having 3 carbon atoms by distillation is applied.

In the first to fourth aspects of the above-described general separation process, it is preferable to perform treatment such as quenching, alkali washing, dehydration and the like as necessary. When the oxygen-containing compound is contained in the reactor outlet gas, at least part of the oxygen-containing compound is removed by the quenching process. When an acid gas such as carbon dioxide is contained in the reactor outlet gas, at least a part of the acid gas is removed by the alkali cleaning.

The separation of water is mainly possible by condensing by compression and cooling. The remaining water is preferably removed with an adsorbent such as a molecular sieve. Water removed by condensation and / or adsorption may be supplied to a wastewater treatment process such as activated sludge, but it may also be used for process water.

When the process of the present invention (hereinafter also referred to as &quot; the present process &quot;) is in the vicinity of steam cracking, the water recovered from the reactor outlet gas is preferably used as a source of steam for crackers. It may also be recycled to the reactor of the present process and used as a diluting gas.

In addition, it is preferable that a hydrocarbon having 2 or less carbon atoms or a hydrocarbon having 3 carbon atoms obtained from the reactor outlet gas is further subjected to a purifying step such as distillation to obtain ethylene and propylene having high purity respectively. The purity of ethylene is 95% or more, preferably 99% or more. More preferably, it is 99.9% or more. The purity of propylene is preferably 95% or more, and more preferably 99% or more. More preferably, it is 99.9% or more.

Ethylene and propylene thus obtained can be used as raw materials for generally produced ethylene and propylene derivatives from the viewpoint of quality such as the amount of impurities. Ethylene can be used, for example, in the presence of ethylene oxide, ethylene glycol, In the production of ethanolamine, glycol ether and the like, chlorinated vinyl monomers, 1,1,1-trichloroethane, vinyl chloride resins and vinylidene chloride are produced by chlorination, and also α-olefins and low- , Or in the production of high-density polyethylene, and in the production of ethylbenzene by the ethylation of benzene, respectively.

The ethylene terephthalate produced from ethylene can also be used as a raw material to produce polyethylene terephthalate. By using an? -Olefin as a raw material, a high alcohol is reacted with an ethylenevinylene as a raw material, and a styrene monomer, an ABS Resin or the like can be produced. Acetaldehyde and its derivative, such as ethyl acetate, can also be produced by a reaction with vinyl acetate through a reaction with acetic acid and a worker reaction.

Propylene can be produced, for example, by ammoxidation in the production of acrylonitrile, by selective oxidation in the production of acrolein, acrylic acid and acrylic acid esters, by oxo reaction in the presence of oxalcohols such as normal butyl alcohol and 2-ethylhexanol It can be applied to production of polypropylene by polymerization of propylene and production of propylene oxide and propylene glycol by selective oxidation of propylene. In addition, acetone can be produced by Walker reaction, and methyl isobutyl ketone can be produced from acetone. Acetone cyanhydrin can also be prepared from acetone, which is ultimately converted to methyl methacrylate. Isopropyl alcohol can also be produced by propylene hydration. Further, cumene produced by alkylating benzene can be used as a starting material to produce phenol, bisphenol A, and polycarbonate resin.

The fluid containing the hydrocarbon having 2 or less carbon atoms and the hydrocarbon having 3 carbon atoms obtained in the third and fourth aspects of the above general separation step is supplied to the production process of ethylene and propylene other than the present process to purify desirable. Examples of the process for producing ethylene and propylene other than the present process include steam cracking such as naphtha or ethane. Accordingly, the facility investment of the present process can be remarkably reduced.

On the other hand, when the ethylene-containing fluid produced in the present process can not be supplied to the production process of ethylene and propylene other than the present process, it is necessary to purify ethylene in the present process. In this case, It is preferable to adopt the mode or the second aspect.

The separation step in the third embodiment

[Separation Process]

 &Lt; Separation of gas components, liquid components and water: Steps (2C) and (3C)

In the present invention, the reactor outlet gas is cooled and the gas fluid (K) after cooling is compressed to form a gas fluid (L), a liquid fluid (M) rich in hydrocarbons having 4 or more carbon atoms and containing an aromatic compound, The gas fluid L is separated into a fluid rich in hydrocarbons having 3 or less carbon atoms and a fluid N rich in hydrocarbons having 4 or more carbon atoms by a general separation process such as distillation (step (2C)) (Step (3C)).

In the step (2C), the reactor outlet gas is usually at a temperature of about 300 to 600 DEG C, but this reactor outlet gas is cooled to about 20 to 200 DEG C. This cooling is usually done with a heat exchanger, which may be directly cooled by mixing with a fluid that is cooler than the gas. The cooled fluid (K) is obtained by compressing, by using a compressor, a knock-out drum, or an oil-water separator, a gas fluid (L) rich in hydrocarbons having 6 or less carbon atoms and a hydrocarbon rich in hydrocarbons having 4 or more carbon atoms and containing an aromatic compound The liquid M and the water-rich fluid. In addition, in the heat exchanger, the fluid to be heat-exchanged with the outlet gas of the reactor is not particularly limited, but is preferably one or a plurality of fluids supplied to the reactor.

The gas fluid L rich in hydrocarbons having 6 or less carbon atoms separated in this step 2C contains a hydrocarbon. In the step (3C), by a general separation process such as distillation, the hydrocarbon fluid L rich in hydrocarbons having 3 or less carbon atoms And a fluid (N) rich in hydrocarbons having a carbon number of 4 or more.

As a first mode of the above general separation process, a fluid having a carbon number of 2 or less and a hydrocarbon-rich fluid having 3 or more carbon atoms is separated by distillation and a hydrocarbon-rich fluid having 3 or more carbon atoms is separated by distillation to obtain a hydrocarbon having 3 carbon atoms Into a fluid (N) rich in hydrocarbons having a carbon number of 4 or more and a rich fluid.

As a second mode of the separation step, a fluid having a carbon number of 3 or less and a hydrocarbon-rich fluid having a carbon number of 4 or more and a hydrocarbon-rich fluid having 3 or less carbon atoms are separated by distillation, A process comprising separating into a hydrocarbon-rich fluid and a hydrocarbon-rich fluid having 3 carbon atoms is applied.

As a third aspect of the separation step, a fluid containing a hydrocarbon having 2 or less carbon atoms and a hydrocarbon having 3 or more carbon atoms and a hydrocarbon-rich fluid having 3 or more carbon atoms and a hydrocarbon-rich fluid having 3 or more carbon atoms is separated by distillation, Into a fluid rich in hydrocarbon and a fluid (N) rich in hydrocarbons having 4 or more carbon atoms.

In a fourth aspect of the separation process, the fluid is separated into a fluid rich in hydrocarbon having 3 or less carbon atoms and a fluid (N) rich in hydrocarbons having 4 or more carbon atoms by distillation, and a fluid rich in hydrocarbons having 3 or less carbon atoms is separated by distillation, A process comprising separating the hydrocarbon into a fluid containing a hydrocarbon having 3 carbon atoms and a hydrocarbon-rich fluid having 3 carbon atoms is applied.

In the above-described process, it is preferable to perform treatment such as quenching, alkali washing, dehydration and the like as necessary. When the oxygen-containing compound is contained in the reactor outlet gas, at least part of the oxygen-containing compound is removed by the quenching process. When an acid gas such as carbon dioxide is contained in the reactor outlet gas, at least a part of the acid gas is removed by the alkali cleaning.

The separation of water is mainly possible by condensing by compression and cooling. The remaining water is preferably removed with an adsorbent such as a molecular sieve. Water removed by condensation and / or adsorption may be supplied to a wastewater treatment process such as activated sludge, but it may also be used in process water or the like.

When the process of the present invention (hereinafter also referred to as &quot; the present process &quot;) is in the vicinity of steam cracking, the water recovered from the reactor outlet gas is preferably used as a source of steam for crackers. It may also be recycled to the reactor of the present process and used as a diluting gas.

In addition, it is preferable that a hydrocarbon having 2 or less carbon atoms or a hydrocarbon having 3 carbon atoms obtained from the reactor outlet gas is further subjected to a purifying step such as distillation to obtain ethylene and propylene having high purity respectively. The purity of ethylene is 95% or more, preferably 99% or more. More preferably, it is 99.9% or more. The purity of propylene is preferably 95% or more, and more preferably 99% or more. More preferably, it is 99.9% or more.

Ethylene and propylene thus obtained can be used for all of the ethylene and propylene derivatives generally produced. Ethylene is produced by, for example, an oxidizing reaction in the production of ethylene oxide, ethylene glycol, ethanolamine, glycol ether and the like by chlorination Vinyl chloride monomer, 1,1,1-trichloroethane, vinyl chloride resin and vinylidene chloride, and also by the polymerization of ethylene to the production of? -Olefin, low density or high density polyethylene, Ethylbenzene and the like.

Polyethylene terephthalate can be produced from ethylene glycol produced from ethylene as a raw material, and a high-molecular-weight polyethylene can be produced by using an α-olefin as a raw material and a high- Resin or the like can be produced. Acetaldehyde and its derivative, such as ethyl acetate, can also be produced by a reaction with vinyl acetate through a reaction with acetic acid and a worker reaction.

Propylene can be produced, for example, by ammoxidation in the production of acrylonitrile, by selective oxidation in the production of acrolein, acrylic acid and acrylic acid esters, by oxo reaction in the presence of oxalcohols such as normal butyl alcohol and 2-ethylhexanol It can be applied to production of polypropylene by polymerization of propylene and production of propylene oxide and propylene glycol by selective oxidation of propylene. In addition, acetone can be produced by Walker reaction, and methyl isobutyl ketone can be produced with acetone. Acetone can also produce acetone cyanhydrin, which is ultimately converted to methyl methacrylate. Isopropyl alcohol can also be produced by propylene hydration. In addition, phenol, bisphenol A, and polycarbonate resin can be produced from cumene produced by alkylating benzene as a raw material.

It is preferable that the fluid containing the hydrocarbon having 2 or less carbon atoms and the hydrocarbon having 3 carbon atoms obtained in the third and fourth aspects of the separation step is supplied to the production process of ethylene and propylene other than the present process and purified Do. Examples of the process for producing ethylene and propylene other than the present process include steam cracking such as naphtha or ethane. Accordingly, the facility investment of the present process can be remarkably reduced.

On the other hand, when the ethylene-containing fluid produced in the present process can not be supplied to the production process of ethylene and propylene other than the present process, it is necessary to purify ethylene in the present process. In this case, It is preferable to adopt the mode or the second aspect.

The first and second modes

 &Lt; Separation and recycling of hydrocarbons having 4 or more carbon atoms: Steps (3A) and (3B)

At least a portion of a hydrocarbon-rich fluid (A) (hereinafter referred to as a hydrocarbon fluid (A) having a carbon number of 4 or more) separated from the reactor outlet gas is recycled to the reactor and the remaining fluid is withdrawn from the process.

Here, &quot; exited from this process &quot; means not to be recycled to the reactor of the present process, and may be directly supplied to another process through the pipe, or may be supplied to another process once stored in the tank through the pipe . It may also be used as fuel without being supplied to another process.

As a first aspect of a method for recycling a hydrocarbon fluid (A) having 4 or more carbon atoms to a reactor, a part (B) of a hydrocarbon fluid (A) having 4 or more carbon atoms is withdrawn from the process, and the remaining fluid (C) (D) in which the concentration of aromatics (wt%) is lower than that of the fluid (C) and the concentration of hydrocarbons having a carbon number of 4 is separated into a fluid (E) lower than the fluid (C) Recycling, and discharging the fluid (E) from the process.

(G) having an aromatic compound concentration lower than that of the fluid (A) and a fluid having a hydrocarbon concentration of a carbon number of 4 lower than that of the fluid (A) by a general separation method such as distillation of a hydrocarbon fluid At least a portion of the fluid I of the fluid G is recycled to the reactor and the remaining fluid H is discharged to the process And a step of extracting from the substrate is applied.

When a raw material containing an olefin raw material having 4 or more carbon atoms and containing paraffin having 4 or more carbon atoms is used, the fluid (B) in the first aspect or the fluid (H) It is difficult to separate and purify an effective component such as butene. Therefore, when the process is in the vicinity of the steam cracking, it is preferable that the process is supplied to the steam cracking and used effectively as the cracker raw material.

As a result, these fluids (B) and (H) can be raw materials for producing ethylene or propylene in steam cracking. At this time, it is preferable that at least a part of the fluid B or the fluid H is brought into contact with the hydrogenation catalyst to supply the fluid having the paraffin concentration higher than the fluid B or the fluid H to the steam cracking. When a fluid having a high olefin concentration is supplied to the cracker of the steam cracking, carbon precipitation easily occurs in the cracker, which is not preferable.

In this case, the total concentration of the aromatic compounds contained in the fluid (B) or the fluid (H) is preferably less than 5.0 vol%, more preferably less than 3.0 vol%. When the concentration of the aromatic compound is high, it is not preferable because a large amount of carbon precipitates when supplied to the cracker and the ethylene yield tends to be lowered.

It is preferable that the fluid (E) in the first aspect or the fluid (F) in the second aspect is mixed with the cracked gasoline fraction such as steam cracking. Accordingly, the fluid E or the fluid F can be effectively used.

The decomposition gasoline referred to herein is a fluid mainly containing paraffins, olefins, dienes, and aromatic compounds having 5 to 10 carbon atoms, and the effective components can be recovered from the cracked gasoline as needed. Examples of the effective component include hydrocarbons having 5 carbon atoms and aromatic compounds such as benzene, toluene and xylene.

If the decomposition gasoline contains hydrocarbons having 4 carbon atoms, hydrocarbons having 4 carbon atoms are mixed in the hydrocarbon solvent having 5 carbon atoms recovered from the decomposition gasoline, which is not preferable. Therefore, it is preferable that the hydrocarbons mixed in the cracked gasoline oil or the hydrocarbons having 4 carbon atoms in the fluid (F) are less than 5% by weight. More preferably less than 2% by weight.

The first aspect is advantageous over the second aspect in terms of both the service cost and the facility investment cost since the load of the separation step such as distillation can be reduced by extracting the fluid B. However, the fluid B is a fluid having the same composition as the fluid A, and the concentration of the aromatic compound is higher than that of the fluid H obtained in the second embodiment. Therefore, the process is selected according to the use of the fluid to be withdrawn.

Third mode

 &Lt; Recycling of hydrocarbons having 4 or more carbon atoms: Step (4C)

A part P of a hydrocarbon-rich fluid N (hereinafter referred to as &quot; hydrocarbon fluid N &quot;) having a carbon number of 4 or more separated in the step 3C is extracted from the present process, And recycled to the reactor. At least a part of the liquid fluid (M) condensed in the compression step is rich in hydrocarbons having 4 or more carbon atoms and containing an aromatic compound is extracted from the present process.

Here, &quot; exited from this process &quot; means that the process is not recycled to the reactor, and may be directly supplied to another process through a pipe, or may be supplied to another process once stored in the tank through the pipe . It may also be used as fuel without being supplied to another process.

The liquid fluid M is distilled so that the concentration of the aromatic compound (weight%) is lower than that of the liquid fluid M and the concentration of hydrocarbons whose carbon number is 4 is lower than the liquid fluid M do. In this case, it is preferable that the fluid R is returned to the point of distribution of one or a plurality of fluids selected from the fluids K, L, N, P, and Q. It is particularly preferable to carry out this distillation operation when a large amount of hydrocarbons having 4 or less carbon atoms are contained in the liquid fluid (M).

In the case of using a raw material containing an olefin having 4 or more carbon atoms and containing paraffin having 4 or more carbon atoms, the fluids (M), (P) and (R) Is difficult to separate and purify. Therefore, when the process is in the vicinity of steam cracking, it is preferable that at least one of these fluids (M), (P) and (R) is supplied to steam cracking and used effectively as a cracker raw material .

This can be a raw material for the production of ethylene or propylene in steam cracking. At this time, at least a part of the fluids (M), (P) and (R) is brought into contact with a hydrogenation catalyst to supply a fluid having a paraffin concentration higher than the fluids (M), (P) . When a fluid having a high olefin concentration is supplied to the cracker of the steam cracking, carbon precipitation easily occurs in the cracker, which is not preferable.

In this case, it is preferable that the total concentration of aromatic compounds contained in the fluids (M), (P) and (R) is less than 5.0% by volume. More preferably, it is less than 3.0% by volume. When the concentration of the aromatic compound is high, it is not preferable because the carbon dioxide is precipitated when supplied to the cracker and the ethylene yield tends to be lowered.

It is preferable that the fluid (S) is mixed with cracked gasoline oil fractions such as steam cracking. Thus, the fluid S can be effectively used. When the concentration of hydrocarbons having 4 or less carbon atoms in the fluid M is low, the fluid M may be directly mixed with decomposed gasoline oil fractions.

The decomposition gasoline referred to herein is a fluid mainly containing paraffins, olefins, dienes, and aromatic compounds having 5 to 10 carbon atoms, and the effective components can be recovered from the cracked gasoline as needed. Examples of the effective component include hydrocarbons having 5 carbon atoms and aromatic compounds such as benzene, toluene and xylene.

If the decomposition gasoline contains hydrocarbons having 4 carbon atoms, hydrocarbons having 4 carbon atoms are mixed in the hydrocarbon solvent having 5 carbon atoms recovered from the decomposition gasoline, which is not preferable. Therefore, the hydrocarbons mixed in the cracked gasoline oil or the hydrocarbon having 4 carbon atoms in the fluid S are preferably less than 5% by weight. More preferably less than 2% by weight.

 <Control of Substrate Concentration at Reactor Inlet>

In the first aspect, the flow rate of the diluent gas such as paraffin contained in the fluid (D) recycled to the reactor can be controlled by controlling the flow rate of the fluid (B) and the fluid (E).

In the second aspect, the flow rate of the diluent gas such as paraffin contained in the fluid (I) recycled to the reactor can be controlled by controlling the flow rate of the fluid (F) and the fluid (H).

In the third aspect, the flow rates of the fluid M and the fluid P, or the fluid P, the fluid R and the fluid S, and further the fluids K, L, (Q) contained in the fluid (Q) recycled to the reactor by controlling the flow rate or the conveying point of the fluid (R) to be returned to the point of any one or two or more fluids selected from The flow rate of the diluent gas can be controlled.

As a result, it is preferable to control the total concentration (substrate concentration) of the olefin having 4 or more carbon atoms and methanol and dimethyl ether in the entire feedstock fed to the reactor to 20% by volume or more and 80% by volume or less.

[Integration with steam cracking]

In steam cracking, a fluid (mainly C4 raffinate-2) having a low value of removing a required component from a hydrocarbon fluid (BB oil fraction) having a carbon number of 4 obtained is often returned to a cracker by hydrogenation.

This process is a very efficient process which can make effective use of each other's low value fluids in that fluids of this value can be used as raw materials and unnecessary fluid can be used in steam cracking in this process.

[Implementation of Process]

Hereinafter, embodiments of the process of the present invention will be described with reference to the drawings.

Figure 1 shows a first embodiment of the process of the invention, and Figure 2 shows a second embodiment.

In Figs. 1 and 2, reference numeral 10 denotes a reactor, 20 a first separation and purification system, and 30A and 30B a second separation and purification system. Reference numerals 101 to 114 denote pipes, respectively.

 &Lt; Description of First Embodiment (Fig. 1)

At least one of an olefin raw material having a carbon number of 4 or more, a hydrocarbon fluid (D) having 4 or more carbon atoms from the second separation and purification system 30A, methanol and dimethyl ether is passed through piping 101, 102, (10). The olefin raw material having 4 or more carbon atoms supplied to the reactor 10 may contain paraffins having 4 or more carbon atoms, for example, normal butane or isobutane. The raw material fluid supplied to the reactor 10 through the pipe 104 may contain butadiene or an aromatic compound. As described above, the butadiene concentration in the raw material fluid is usually 2.0 vol% or less, and the total amount of aromatic compounds is usually less than 0.05 in a molar ratio with respect to the total amount of olefins having 4 or more carbon atoms contained in the raw material fluid of the pipe 104 . The raw fluid refers to the sum of the fluids supplied through the pipes 101, 102 and 103. They do not necessarily have to be joined before entering the reactor 10 but may be supplied to the reactor 10 . The raw material gas supplied to the reactor 10 reacts in contact with the catalyst in the reactor 10, and a reactor outlet gas containing propylene, other olefins, paraffins, aromatic compounds and water is obtained.

The outlet gas of the reactor is fed to a general separation and purification system 20 such as cooling, compression and distillation via a pipe 105. In this separation and purification system 20, a fluid rich in hydrocarbons having 3 or less carbon atoms and a hydrocarbon having 4 or more carbon atoms Is separated into a rich fluid (A) and a water-rich fluid, and is taken out through piping (106, 108, 107), respectively. Here, a hydrocarbon-rich fluid having three or less carbon atoms represents one or more fluids. For example, it may be a single fluid containing all of the hydrocarbons having 3 or less carbon atoms, or may be a fluid containing a hydrocarbon-rich hydrocarbon having 2 or less carbon atoms and a hydrocarbon-rich fluid having 3 carbon atoms or a hydrocarbon having 2 or less carbon atoms and a hydrocarbon having 3 carbon atoms Two fluids such as a fluid and a hydrocarbon-rich fluid having three carbon atoms may be used. Further, three or more fluids may be used.

A part of the fluid A rich in hydrocarbons having 4 or more carbon atoms is extracted from the piping 109 to the outside of the process and the remaining fluid C is supplied to the general separation and purification system 30A such as distillation through the piping 110. [ A part of the fluid (B) may be ejected out of the process. At this time, the fluid B may be used as a cracker raw material for steam cracking. In this case, it is preferable that the outflow fluid (B) is brought into contact with the hydrogenation catalyst and supplied to the steam cracking as a fluid having an increased paraffin concentration. At this time, it is preferable that the total concentration of aromatic compounds of the outgoing fluid (B) is less than 5.0% by volume.

The separation purification system 30A separates the fluid D in which the aromatic compound concentration is lower than the fluid C and the fluid E in which the concentration of hydrocarbons having 4 or more carbon atoms is lower than the fluid C, Is recycled to reactor 10 via piping 102 and fluid E is withdrawn from piping 111 from the process. The outflow fluid (E) may be mixed with cracked gasoline oil fractions such as steam cracking. In this case, it is preferable that the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (E) is less than 5% by weight.

A part of fluid (hereinafter referred to as &quot; fluid X &quot;) of the fluid D may be ejected out of the process. At this time, the fluid X may be used as a cracker raw material for steam cracking. In this case, it is preferable that the outflowing fluid X is brought into contact with the hydrogenation catalyst to supply steam cracking as a fluid having a high paraffin concentration. At this time, it is preferable that the total concentration of the aromatic compound in the outflow fluid X is less than 5.0 mol%.

The fluids (D) and fluids (X) are not necessarily required, but it is preferred that at least any fluid is withdrawn from the process to prevent paraffin accumulation.

 &Lt; Description of Second Embodiment (Fig. 2)

At least one of the olefin raw materials having a carbon number of 4 or more, the hydrocarbon fluid (I) having 4 or more carbon atoms from the second separation and purification system 30B, methanol and dimethyl ether is passed through the piping 101, 102, (10). Thereafter, in the first separation and purification system 20, until the separation gas is separated from the outlet gas of the reactor 10 into a hydrocarbon-rich fluid having 3 or less carbon atoms, a hydrocarbon fluid A having 4 or more carbon atoms and a fluid rich in water 1 are the same as those in Fig. 1, and the description thereof will be omitted.

The hydrocarbon fluid A having a carbon number of 4 or more is supplied from the pipe 108 to a general separation and purification system 30B such as distillation. In the separation and purification system 30B, a fluid G having an aromatic compound concentration lower than that of the fluid A and a fluid F having a hydrocarbon concentration of 4 or more carbon atoms lower than the fluid A are separated. Fluid (F) is withdrawn from the process from piping (112). The outflow fluid (F) may be mixed with decomposed gasoline oil fractions such as steam cracking. In that case, it is preferable that the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (F) is less than 5% by weight.

The fluid G is taken out of the piping 113 and a part H of the fluid G is discharged from the process through the piping 114 and the remaining fluid I is recycled to the reactor 10 via the piping 102 . The outflow fluid (H) may be used as a cracker raw material for steam cracking. In this case, it is preferable that the fluid (H) is brought into contact with the hydrogenation catalyst and supplied to the steam cracking as a fluid having an increased paraffin concentration. The total concentration of the aromatic compound in the fluid (H) at this time is preferably less than 5.0% by volume.

The extraction of the fluid (H) out of the process is not necessarily required. However, in order to prevent the accumulation of paraffins, it is preferable that at least a part of the fluid is extracted from the process.

[Implementation of Process]

 &Lt; Third Embodiment (Fig. 3) >

Hereinafter, embodiments of the process of the present invention will be described with reference to the drawings.

Figure 3 illustrates one aspect of the process of the present invention.

3, reference numeral 13 denotes a reactor, reference numeral 23 denotes a compressor, reference numeral 33 denotes a knockout drum, reference numeral 43 denotes an oil water separator, reference numeral 53 denotes a first separation and purification system, reference numeral 63 denotes a second separation purification system to be. (301) to (315) represent pipes.

At least one of an olefin feedstock having a carbon number of 4 or more, a hydrocarbon fluid (Q) having a carbon number of 4 or more from the first separation and purification system 53, methanol and dimethyl ether is passed through the piping 301, 302, (13). The olefin raw material having 4 or more carbon atoms supplied to the reactor 13 may contain paraffins having 4 or more carbon atoms, for example, normal butane or isobutane. The raw material fluid supplied to the reactor 13 through the pipe 304 may contain butadiene or an aromatic compound. As described above, the butadiene concentration in the raw material fluid is usually 2.0 vol% or less, and the total amount of aromatic compounds is usually less than 0.05 in terms of a molar ratio with respect to the total amount of olefins having 4 or more carbon atoms contained in the raw material fluid of the pipe 304 . The raw material fluid means the sum of the fluids supplied through the pipes 301, 302 and 303. They do not necessarily have to be joined before entering the reactor 13 but may be supplied to the reactor 13 . The raw material gas supplied to the reactor 13 reacts in contact with the catalyst in the reactor 13, and a reactor outlet gas containing propylene, other olefins, paraffins, aromatic compounds and water is obtained.

The reactor outlet gas is cooled, for example, through a heat exchanger, and the cooled gas fluid K is pressurized by the compressor 23 from the pipe 305. The number of the compressors 23 may be one, but a plurality is preferable. After each compressor (23), a heat exchanger and a knock-out drum (33) are provided, and after the compressed gas is cooled, it is separated into a gaseous fluid (L) and a condensed component. The condensed component is fed to the oil water separator 43 via the pipe 308 and separated into a fluid M rich in hydrocarbons having a carbon number of 4 or more and a fluid rich in water and the fluid rich in water is withdrawn from the pipe 310 And the liquid fluid M rich in hydrocarbons having 4 or more carbon atoms is fed from the pipe 309 to the second separation and purification system 63.

The gas fluid L separated from the knock-out drum 33 is fed to a general first separation and purification system 53 such as distillation via a pipe 307. A fluid rich in hydrocarbon having 3 or less carbon atoms and a hydrocarbon having 4 or more carbon atoms Rich fluid N, and is taken out through the pipes 313 and 314, respectively. Here, a hydrocarbon-rich fluid having three or less carbon atoms represents one or more fluids. For example, it may be a single fluid containing all of the hydrocarbons having 3 or less carbon atoms, or may be a fluid containing a hydrocarbon-rich hydrocarbon having 2 or less carbon atoms and a hydrocarbon-rich fluid having 3 carbon atoms or a hydrocarbon having 2 or less carbon atoms and a hydrocarbon having 3 carbon atoms Two fluids such as a fluid and a hydrocarbon-rich fluid having three carbon atoms may be used. Further, three or more fluids may be used.

A part P of the hydrocarbon N rich in carbon atoms having a carbon number of 4 or more is withdrawn from the process through the pipe 315 and the remaining fluid Q is recycled to the reactor 13 through the pipe 302. [ The fluid (P) may be used as a cracker raw material for steam cracking. In this case, it is preferable that the fluid (P) is brought into contact with the hydrogenation catalyst and supplied to the steam cracking as a fluid having an increased paraffin concentration. The total concentration of the aromatic compound in the fluid (P) at this time is preferably less than 5.0% by volume.

On the other hand, the liquid fluid M separated in the oil water separator 43 is a liquid component rich in hydrocarbons having 4 or more carbon atoms and containing an aromatic compound, which may be extracted from the process as it is. In this case, ) May be used as a cracker raw material for steam cracking. In this case, it is preferable that the fluid M is brought into contact with the hydrogenation catalyst to supply steam cracking as a fluid having an increased paraffin concentration. The total concentration of the aromatic compound in the fluid (M) at this time is preferably less than 5.0% by volume.

When the concentration of hydrocarbons having 4 carbon atoms in the liquid fluid (M) is low, it may be mixed with cracked gasoline fractions such as steam cracking. In this case, it is preferable that the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (M) is less than 5% by weight.

At least a part of the liquid fluid M is a second separation and purification system 60 which is a general separation process such as distillation wherein the concentration of the aromatic compound in the liquid R is lower than that of the liquid fluid M, It is preferable to separate the fluid S into a fluid S lower than the fluid fluid M. The separated fluid R is extracted from the piping 111. The fluid R is discharged from the piping 111 through which the fluid K flows, the fluid L, the fluid N, the fluid P, 305, 307, 314, 315, and 302, respectively.

On the other hand, the fluid S is extracted from the pipe 312, and the fluid S may be mixed with cracked gasoline fractions such as steam cracking. In this case, it is preferable that the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (S) is less than 5% by weight.

The extraction of the fluid P out of the process is not necessarily required, but it is preferable that at least a part of the fluid is withdrawn from the process in order to prevent accumulation of paraffins.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[Catalyst preparation]

The catalysts used in the following Examples and Comparative Examples were prepared as follows.

 <Preparation Example of Catalyst>

26.6 g of tetra-n-propylammonium bromide (TPABr) and 4.8 g of sodium hydroxide were sequentially dissolved in 280 g of water, and then 75 g of colloidal silica (SiO ₂ = 40 wt%, Al <0.1 wt% Was slowly added and stirred for 10 minutes to obtain a water gel. Next, this gel was poured into a 1000 ml autoclave, and hydrothermal synthesis was conducted at 170 캜 for 72 hours while stirring at 300 rpm under magnetic pressure. The product was separated from the solid component by pressure filtration, sufficiently washed with water, and then dried at 100 DEG C for 24 hours. The dried catalyst was fired at 550 DEG C for 6 hours under air circulation to obtain Na-type aluminosilicate.

-2.0 g of this Na-type aluminosilicate was suspended in 40 ml of a 1 M ammonium nitrate aqueous solution and stirred at 80 캜 for 2 hours. After the treatment, the solid component was separated by suction filtration and sufficiently washed with water, suspended again in 40 ml of a 1 M ammonium nitrate aqueous solution, and stirred at 80 캜 for 2 hours. After the treatment, the solid component was separated by suction filtration, sufficiently washed, and then dried at 100 ° C for 24 hours. The dried catalyst was calcined at 500 占 폚 for 4 hours under air circulation to obtain H-type aluminosilicate.

This catalyst was confirmed to have an MFI type zeolite structure by XRD (X-ray diffraction). The composition of the catalyst was determined by chemical analysis and found to be SiO ₂ / Al ₂ O ₃ = 1100 (molar ratio).

[Production of propylene]

Examples of production and comparative examples of propylene using the above catalyst are described above.

&Lt; Example 1 >

Propylene was prepared using the above catalyst.

In the reaction, a mixture of 0.10 g of the catalyst and 1.0 g of quartz was charged into a quartz reaction tube having an inner diameter of 6 mm by using a normal pressure fixed bed flow reactor. In this reactor, isobutene (40 vol%), methanol (20 vol%), benzene (10 vol%), and the like were used as simulated gases corresponding to the reactor inlet gas (piping 104 in Fig. 1 or 2) 0.8 vol%), butadiene (0.1 vol%) and isobutane (39.1 vol%) were supplied through an evaporator. The reaction temperature (reactor inlet gas temperature) was 550 캜. The product was analyzed by gas chromatography 70 minutes after the initiation of the reaction. Table 1 shows reaction conditions and reaction results at that time.

The selectivity of propylene was 54.8%, which was very high.

Further, the reaction was continued, and the time until the methanol conversion rate was lower than 99% was evaluated as the catalyst lifetime. As a result, the catalyst lifetime was 312 hours.

&Lt; Example 2 >

The reaction was carried out in the same manner as in Example 1 except that the concentration of benzene fed to the reactor was 1.6 vol% and the isobutane concentration was 38.3 vol%. 70 minutes after the initiation of the reaction, the product was analyzed by gas chromatography. Table 1 shows reaction conditions and reaction results at that time.

The selectivity of propylene was 54.4%, which was very high.

Further, the reaction was continued, and the time until the methanol conversion rate was lower than 99% was evaluated as the catalyst lifetime. As a result, the catalyst lifetime was 305 hours.

&Lt; Comparative Example 1 &

The reaction was carried out in the same manner as in Example 1 except that the concentration of benzene fed to the reactor was 3.2% by volume and the isobutane concentration was 36.7% by volume. The product was analyzed by gas chromatography 70 minutes after the initiation of the reaction. Table 1 shows reaction conditions and reaction results at that time.

The selectivity of propylene was 51.4%, which was very low compared with Examples 1 and 2.

This is because unnecessary consumption of butene and / or methanol to be originally used for the production of propylene is caused by the reaction of butene and / or methanol with benzene and the production of alkylated benzene.

Further, the reaction was continued, and the time until the methanol conversion rate was lower than 99% was evaluated as the catalyst lifetime. As a result, the catalyst lifetime was 221 hours, which was very short as compared with Examples 1 and 2. This is presumably because the alkylated benzene blocks the pores of the catalyst and promotes caulking.

Thus, in accordance with the method of the present invention, lowering the aromatic compound concentration at the inlet of the reactor by withdrawing at least a part of the aromatic compound without recycling is very effective in achieving high propylene yield and inhibiting deterioration of catalyst caulking.

While the invention has been described in detail and with reference to specific embodiments thereof, it is evident to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

The present application is based on Japanese Patent Application (Japanese Patent Application 2006-255503) filed on September 21, 2006, and Japanese Patent Application (Japanese Patent Application 2006-255504) filed on September 21, 2006, The content is hereby incorporated by reference.

The present invention can provide a new and economical process for producing propylene by reacting at least one of olefins having 4 or more carbon atoms with methanol and dimethyl ether, and a new and economical process incorporating this process and steam cracking .

Claims (63)

A process for producing propylene by contacting an olefin having 4 or more carbon atoms and a raw material containing at least one of methanol and dimethyl ether in the presence of a catalyst in a reactor, The aromatic compound contained in the reactor outlet gas (reactor outlet gas) is withdrawn, The olefin having 4 or more carbon atoms contained in the reactor outlet gas (reactor outlet gas) is brought into contact with the catalyst again in the reactor, Wherein the total amount of the aromatic compounds contained in the total raw materials supplied to the reactor is less than 0.05 in a molar ratio with respect to the total amount of the olefins having 4 or more carbon atoms contained in the entire raw materials supplied to the reactor. The method according to claim 1, Characterized in that said olefin raw material having 4 or more carbon atoms contains paraffins having 4 or more carbon atoms. 3. The method of claim 2, Wherein the paraffins contain at least one of normal butane and isobutane. 4. The method according to any one of claims 1 to 3, Wherein the feedstock fed to the reactor contains butadiene. 4. The method according to any one of claims 1 to 3, Wherein the amount of the olefin having 4 or more carbon atoms supplied to the reactor is in the range of 0.2 to 10 in terms of molar ratio with respect to the total number of moles of methanol fed to the reactor and twice the number of moles of dimethyl ether. 4. The method according to any one of claims 1 to 3, Wherein the total concentration (substrate concentration) of the olefin having 4 or more carbon atoms and methanol and dimethyl ether contained in the entire raw material supplied to the reactor is controlled to 20 vol% or more and 80 vol% or less. (1), (2) and (3A) in the production of propylene by contacting a raw material containing at least one of an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether in the presence of a catalyst in a reactor, Comprising: Wherein the total amount of the aromatic compounds contained in the total raw materials supplied to the reactor is less than 0.05 in a molar ratio with respect to the total amount of the olefins having 4 or more carbon atoms contained in the entire raw materials supplied to the reactor. Process (1): An olefin feedstock having a carbon number of 4 or more, a recycled hydrocarbon fluid (D) recycled from the process (3A), and at least one of methanol and dimethyl ether are fed into the reactor, and the molar flow rate of olefins having 4 or more carbon atoms Is brought into contact with the catalyst under reaction conditions of 20% or more and less than 90% with respect to the molar flow rate of the olefin at the inlet of the reactor, and a gas containing propylene and other olefins, paraffins, aromatic compounds, and water Reactor outlet gas) Process (2): A process of separating the reactor outlet gas in the above-mentioned process (1) into a fluid rich in hydrocarbons having 3 or less carbon atoms, a fluid (A) rich in hydrocarbons having 4 or more carbon atoms, and a fluid rich in water Step (3A): At least part of the fluid (C) of the fluid (A) in the step (2) is mixed with the fluid (D) whose aromatic compound concentration is lower than the fluid (C) Separating the fluid (E) into a fluid (E) lower than the fluid (C), recycling the fluid (D) to the reactor, and withdrawing the fluid (E) from the process. (1), (2) and (3A) in the production of propylene by contacting a raw material containing at least one of an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether in the presence of a catalyst in a reactor, Comprising: Wherein the total amount of the aromatic compounds contained in the total raw materials supplied to the reactor is less than 0.05 in a molar ratio with respect to the total amount of the olefins having 4 or more carbon atoms contained in the entire raw materials supplied to the reactor. Process (1): An olefin feedstock having a carbon number of 4 or more, a recycled hydrocarbon fluid (D) recycled from the process (3A), and at least one of methanol and dimethyl ether are fed into the reactor, and the molar flow rate of olefins having 4 or more carbon atoms Is brought into contact with the catalyst under reaction conditions of 20% or more and less than 90% with respect to the molar flow rate of the olefin at the inlet of the reactor, and a gas containing propylene and other olefins, paraffins, aromatic compounds, and water Reactor outlet gas) Step (2): A step of separating the reactor outlet gas from the above-mentioned step (1) into a fluid rich in hydrocarbons having 3 or less carbon atoms, a fluid (A) rich in hydrocarbons having 4 or more carbon atoms and a fluid rich in water Step (3A): A part (B) of the fluid (A) in the step (2) is withdrawn from the process and the remaining fluid (C) D) and a hydrocarbon having a carbon number of 4 is separated into a fluid (E) lower than the fluid (C), and the fluid (D) is recycled to the reactor and the fluid (E) is withdrawn from the process. 9. The method according to claim 7 or 8, An olefin feedstock comprising at least two reactors connected in series to the reactor, the feedstock comprising an olefin feed having at least 4 carbon atoms; At least one of methanol and dimethyl ether; Then, at least one of the recycled hydrocarbons-containing fluid (D) is divided and supplied to the first-stage reaction section and the second-stage and subsequent reaction sections. 9. The method of claim 8, Wherein the fluid (B) is supplied to a steam cracking process and used as a cracker raw material. 11. The method of claim 10, Wherein at least a portion of the fluid (B) is contacted with a hydrogenation catalyst and then supplied to a steam cracking process. 11. The method according to claim 8 or 10, Wherein the total concentration of aromatic compounds contained in the fluid (B) is less than 5.0% by volume. 9. The method according to claim 7 or 8, Characterized in that the fluid (E) is mixed with the cracked gasoline fraction (fraction) of the steam cracking process. 9. The method according to claim 7 or 8, Wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (E) is less than 5 wt%. 11. The method according to claim 8 or 10, The total concentration (substrate concentration) of the olefin having 4 or more carbon atoms and the amount of the methanol and the dimethyl ether contained in the entire raw material supplied to the reactor is controlled to 20 volume% or more and 80 volume% or less by controlling the flow rate of the fluid (B) % Or less. (1), (2) and (3B), which comprises reacting a mixture containing an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether in the presence of a catalyst in a reactor to produce propylene, Comprising: Wherein the total amount of the aromatic compounds fed to the reactor in the following step (1) is less than 0.05 in a molar ratio with respect to the total amount of the olefins having 4 or more carbon atoms supplied to the reactor. At least one of an olefin raw material having a carbon number of 4 or more, a recycled hydrocarbon fluid (I) recycled from the step (3B), and at least one of methanol and dimethyl ether is fed to the reactor, and the molar flow rate of the olefin having 4 or more carbon atoms at the outlet of the reactor Is brought into contact with the catalyst under the reaction conditions of 20% or more and less than 90% with respect to the molar flow rate of the olefin at the inlet, and a gas containing propylene and other olefins, paraffins, aromatic compounds and water Gas) Step (2): a step of separating the reactor outlet gas from the above-mentioned step (1) into a fluid rich in hydrocarbon having 3 or less carbon atoms, a fluid (A) rich in hydrocarbons having 4 or more carbon atoms and a fluid rich in water Step (3B): The fluid (A) in the above step (2) is mixed with the fluid (G) having the aromatic compound concentration lower than the fluid (A) and the fluid (F) , And recycling at least part (I) of the fluid (G) to the reactor. (1), (2) and (3B), which comprises reacting a mixture containing an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether in the presence of a catalyst in a reactor to produce propylene, Comprising: Wherein the total amount of the aromatic compounds fed to the reactor in the following step (1) is less than 0.05 in a molar ratio with respect to the total amount of the olefins having 4 or more carbon atoms supplied to the reactor. At least one of an olefin raw material having a carbon number of 4 or more, a recycled hydrocarbon fluid (I) recycled from the step (3B), and at least one of methanol and dimethyl ether is fed to the reactor, and the molar flow rate of the olefin having 4 or more carbon atoms at the outlet of the reactor Is brought into contact with the catalyst under the reaction conditions of 20% or more and less than 90% with respect to the molar flow rate of the olefin at the inlet, and a gas containing propylene and other olefins, paraffins, aromatic compounds and water Gas) Step (2): a step of separating the reactor outlet gas from the above-mentioned step (1) into a fluid rich in hydrocarbon having 3 or less carbon atoms, a fluid (A) rich in hydrocarbons having 4 or more carbon atoms and a fluid rich in water Step (3B): The fluid (A) in the above step (2) is mixed with the fluid (G) having the aromatic compound concentration lower than the fluid (A) and the fluid (F) , Recycling the portion (I) of the fluid (G) to the reactor and ejecting the remaining fluid (H) from the process, while ejecting the fluid (F) from the process. 18. The method according to claim 16 or 17, An olefin feedstock comprising at least two reactors connected in series to the reactor and having a carbon number of 4 or more and fed to the reactor; At least one of methanol and dimethyl ether; Then, at least one of the recycled hydrocarbons-containing fluid (I) is divided and supplied into the first reaction zone and the second reaction zone. 18. The method of claim 17, Wherein the fluid (H) is supplied to a steam cracking process and used as a cracker raw material. 20. The method of claim 19, Wherein at least a portion of the fluid (H) is contacted with a hydrogenation catalyst and then supplied to a steam cracking process. The method according to claim 17 or 19, Wherein a total concentration of aromatic compounds contained in the fluid (H) is less than 5.0 vol%. 18. The method according to claim 16 or 17, Characterized in that the fluid (F) is mixed with the cracked gasoline fraction of the steam cracking process. 18. The method according to claim 16 or 17, Wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (F) is less than 5 wt%. 18. The method of claim 17, By controlling the flow rate of the fluid (F) and the fluid (H), the total concentration (substrate concentration) of the olefin having 4 or more carbon atoms and the methanol and the dimethyl ether contained in the entire raw materials supplied to the reactor is 20 vol% By weight based on the total amount of propylene. 18. A method according to any one of claims 7, 8, 16 and 17, Wherein the step (2) separates the hydrocarbon-rich fluid having a carbon number of 2 or less and the hydrocarbon-rich fluid having a carbon number of 3 or more by distillation, And separating the fluid rich in hydrocarbons into a fluid rich in hydrocarbon having 3 carbon atoms and a fluid rich in hydrocarbon having 4 or more carbon atoms by distillation. 18. A method according to any one of claims 7, 8, 16 and 17, The step (2) separates the hydrocarbon-rich fluid having a carbon number of 3 or less and the hydrocarbon-rich fluid having 4 or more carbon atoms by distillation, separating the condensed water from the reactor outlet gas by the cooling and compression process, By mass of a hydrocarbon-rich fluid into a fluid rich in hydrocarbons having 2 or less carbon atoms and a hydrocarbon rich in carbon atoms having 3 or less carbon atoms by distillation. 18. A method according to any one of claims 7, 8, 16 and 17, After the step (2) removes water from the reactor outlet gas by condensation and dehydration by a cooling and compression process, a fluid containing a hydrocarbon having 2 or less carbon atoms and a hydrocarbon having 3 carbon atoms and a hydrocarbon richer than 3 carbon atoms And separating the fluid rich in hydrocarbons having 3 or more carbon atoms into a fluid rich in hydrocarbon having 3 carbon atoms and a fluid rich in hydrocarbon having 4 or more carbon atoms by distillation. 18. A method according to any one of claims 7, 8, 16 and 17, The step (2) separates the hydrocarbon-rich fluid having a carbon number of 3 or less and the hydrocarbon-rich fluid having 4 or more carbon atoms by distillation, separating the condensed water from the reactor outlet gas by the cooling and compression process, By mass of a hydrocarbon-rich fluid is separated into a fluid containing a hydrocarbon having 2 or less carbon atoms and a hydrocarbon containing 3 carbon atoms and a hydrocarbon-rich fluid having 3 or less carbon atoms by distillation. 18. A method according to any one of claims 7, 8, 16 and 17, Wherein the olefin raw material having 4 or more carbon atoms contains paraffins having 4 or more carbon atoms. 30. The method of claim 29, Wherein the paraffins contain at least one of normal butane and isobutane. 18. A method according to any one of claims 7, 8, 16 and 17, Wherein the feedstock fed to the reactor contains butadiene. 18. A method according to any one of claims 7, 8, 16 and 17, Wherein the amount of the olefin having 4 or more carbon atoms supplied to the reactor is in the range of 0.2 to 10 in terms of molar ratio with respect to the total number of moles of methanol fed to the reactor and twice the number of moles of dimethyl ether. 18. A method according to any one of claims 7, 8, 16 and 17, Wherein the olefin raw material having 4 or more carbon atoms supplied to the reactor contains a hydrocarbon fluid having 4 carbon atoms obtained by the steam cracking process. (1C), (2C), and (3C) in a process for producing propylene by contacting a mixture containing an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether in the presence of a catalyst in a reactor, And (4C) And the total amount of aromatic compounds contained in all the raw materials supplied to the reactor is less than 0.05 in a molar ratio with respect to the total amount of olefins having 4 or more carbon atoms contained in all raw materials supplied to the reactor.  Process (1C): An olefin feedstock having a carbon number of 4 or more, a recycled hydrocarbon fluid (Q) recycled from the process (4C), and at least one of methanol and dimethyl ether are fed to the reactor, and the molar flow rate of the olefin having 4 or more carbon atoms Is contacted with the catalyst under reaction conditions of 20% or more and less than 90% with respect to the molar flow rate of the olefin at the inlet of the reactor, and a gas containing propylene and other olefins, paraffins, aromatic compounds and water Outlet gas) Step (2C): The reactor outlet gas from the step (1C) is cooled to obtain a gas fluid (L), a liquid fluid (M) rich in hydrocarbons having 4 or more carbon atoms and containing an aromatic compound, Separation process Step (3C): A step of separating the gas fluid (L) in the step (2C) into a fluid rich in hydrocarbons having 3 or less carbon atoms and a fluid (N) rich in hydrocarbons having 4 or more carbon atoms Step (4C): a step of recycling at least part of the fluid (Q) of the fluid (N) to the reactor. (1C), (2C), and (3C) in a process for producing propylene by contacting a mixture containing an olefin having 4 or more carbon atoms and at least one of methanol and dimethyl ether in the presence of a catalyst in a reactor, And (4C) And the total amount of aromatic compounds contained in all the raw materials supplied to the reactor is less than 0.05 in a molar ratio with respect to the total amount of olefins having 4 or more carbon atoms contained in all raw materials supplied to the reactor. Process (1C): An olefin feedstock having a carbon number of 4 or more, a recycled hydrocarbon fluid (Q) recycled from the process (4C), and at least one of methanol and dimethyl ether are fed to the reactor, and the molar flow rate of the olefin having 4 or more carbon atoms Is brought into contact with the catalyst under reaction conditions of 20% or more and less than 90% with respect to the molar flow rate of the olefin at the inlet of the reactor, and a gas containing propylene and other olefins, paraffins, aromatic compounds and water Outlet gas) Step (2C): The reactor outlet gas from the above-mentioned step (1C) is cooled and the gas fluid (K) after cooling is compressed to form a gas fluid (L), a liquid containing a large amount of hydrocarbons having 4 or more carbon atoms A process for separating the fluid (M) and the water-rich fluid Step (3C): A step of separating the gas fluid (L) in the step (2C) into a fluid rich in hydrocarbons having 3 or less carbon atoms and a fluid (N) rich in hydrocarbons having 4 or more carbon atoms Step (4C): a step of withdrawing part (P) of the fluid (N) from the process and recycling the remaining fluid (Q) to the reactor. 36. The method of claim 35, The liquid fluid M is separated by distillation into a fluid having an aromatic compound concentration lower than that of the liquid fluid M and a fluid S having a carbon concentration of 4 carbon atoms lower than the liquid fluid M. &Lt; / RTI &gt; 37. The method of claim 36, Wherein said fluid R is returned to the point of flow of any one or more fluids selected from among said fluids K, L, M, P and Q. Way. 35. The method according to claim 34 or 35, The process (3C) separates the gas fluid (L) into a fluid rich in hydrocarbons having 2 or less carbon atoms and a fluid rich in hydrocarbons having 3 or more carbon atoms by distillation, and further, a fluid rich in hydrocarbons having 3 or more carbon atoms is separated by distillation , And a step of separating into a fluid rich in hydrocarbon having 3 carbon atoms and a fluid (N) rich in hydrocarbon having 4 or more carbon atoms. 35. The method according to claim 34 or 35, (3C) separates the gas fluid (L) into a fluid rich in hydrocarbon having 3 or less carbon atoms and a fluid (N) rich in hydrocarbons having 4 or more carbon atoms by distillation, and further a hydrocarbon-rich fluid having 3 or less carbon atoms To a fluid rich in hydrocarbons having 2 or less carbon atoms and a fluid rich in hydrocarbons having 3 carbon atoms by distillation. 35. The method according to claim 34 or 35, The step (3C) separates the gas fluid (L) into a fluid containing a hydrocarbon having 2 or less carbon atoms and a hydrocarbon having 3 carbon atoms and a hydrocarbon-rich fluid having 3 or more carbon atoms by distillation and further adding a hydrocarbon having 3 or more carbon atoms And separating the rich fluid into a fluid rich in hydrocarbon having 3 carbon atoms and a fluid rich in hydrocarbon having 4 or more carbon atoms by distillation. 35. The method according to claim 34 or 35, The process (3C) is characterized in that the gas fluid (L) is separated into a fluid rich in hydrocarbon having 3 or less carbon atoms and a fluid (N) rich in hydrocarbons having 4 or more carbon atoms by distillation, And separating the fluid into a fluid containing a hydrocarbon having 2 or less carbon atoms and a hydrocarbon having 3 or more carbon atoms and a hydrocarbon rich fluid having 3 carbon atoms by distillation. 35. The method according to claim 34 or 35, An olefin feedstock having not more than 4 carbon atoms and being fed to the reactor, wherein the reactor comprises two or more reactors connected in series; At least one of methanol and dimethyl ether; Then, at least one of the recycled hydrocarbons-containing fluid is divided and supplied to the first-stage reaction section and the second-stage and subsequent reaction sections. 35. The method according to claim 34 or 35, Wherein the olefin raw material having 4 or more carbon atoms contains paraffins having 4 or more carbon atoms. 44. The method of claim 43, Wherein the paraffins comprise at least one of normal butane and isobutane. 35. The method according to claim 34 or 35, Wherein the feedstock fed to the reactor contains butadiene. 36. The method of claim 35, Wherein at least one of the fluid (M) and the fluid (P) is supplied to a steam cracking process and used as a cracker raw material. 47. The method of claim 46, Wherein at least a part of at least one of the fluid (M) and the fluid (P) is brought into contact with the hydrogenation catalyst, and then supplied to the steam cracking process. 36. The method of claim 35, Wherein the total concentration of aromatic compounds contained in at least one of the fluid (M) and the fluid (P) is less than 5.0% by volume. 35. The method according to claim 34 or 35, Characterized in that the fluid (M) is mixed with the cracked gasoline fraction of the steam cracking process. 35. The method according to claim 34 or 35, Wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (M) is less than 5 wt%. 36. The method of claim 35, By controlling the flow rate of the fluid (M) and the fluid (P), the total concentration (substrate concentration) of the olefin having 4 or more carbon atoms and the methanol and the dimethyl ether contained in the entire raw material supplied to the reactor is 20 volume% or more and 80 volume % Or less. 37. The method of claim 36, Wherein the fluid (R) is supplied to a steam cracking process and used as a cracker raw material. 53. The method of claim 52, Wherein at least a portion of the fluid (R) is contacted with a hydrogenation catalyst and then fed to a steam cracking process. 37. The method of claim 36, And the total concentration of aromatic compounds contained in the fluid (R) is less than 5.0 vol%. 37. The method of claim 36, Characterized in that the fluid (S) is mixed with the cracked gasoline fraction of the steam cracking process. 37. The method of claim 36, Wherein the total concentration of hydrocarbons having 4 carbon atoms contained in the fluid (S) is less than 5 wt%. 37. The method of claim 36, The total concentration (substrate concentration) of the olefin having 4 or more carbon atoms and the methanol and the dimethyl ether contained in the entire raw material supplied to the reactor is controlled to be 20 vol% by controlling the flow rate of the fluid P, the fluid R and the fluid S % Or more and 80 volume% or less. 58. The method according to any one of claims 36, 52 and 54 to 57, When returning the fluid R to a point of any one or two or more fluids selected from the fluids K, L, N, P and Q, (Substrate concentration) of olefins having 4 or more carbon atoms and methanol and dimethyl ether contained in the entire raw material supplied to the reactor is controlled to be 20 vol% or more and 80 vol% or less by controlling the point and the flow rate thereof Propylene. 35. The method according to claim 34 or 35, Wherein the amount of the olefin having 4 or more carbon atoms supplied to the reactor is 0.2 to 10 in molar ratio with respect to the sum of the number of moles of methanol fed to the reactor and twice the number of moles of dimethyl ether. 35. The method according to claim 34 or 35, Wherein the olefin raw material having 4 or more carbon atoms supplied to the reactor contains a hydrocarbon fluid having 4 carbon atoms obtained by the steam cracking process. delete delete delete

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