KR20090059127A - Process for production of propylene - Google Patents

Abstract

Disclosed is a novel process for producing propylene by using ethylene and at least one member selected from methanol and dimethyl ether as starting materials, which can reduce the amount of unreacted ethylene to be recycled and has low equipment cost and running cost. Specifically disclosed is a process for producing propylene by using ethylene and at least one member selected from methanol and dimethyl ether as starting materials, which comprises reacting ethylene and at least one member selected from methanol and dimethyl ether under specific conditions to produce a fluid containing an olefin having 4 or more carbon atoms, and then reacting at least a part of the olefin having 4 or more carbon atoms contained in the fluid with at least one member selected from methanol and dimethyl ether under specific conditions, thereby producing propylene.

Description

Process for Producing Propylene {PROCESS FOR PRODUCTION OF PROPYLENE}

The present invention relates to a process for producing propylene using at least one of ethylene, methanol and dimethyl ether as a raw material.

As a method for producing propylene, conventionally, steam cracking of naphtha and ethane is generally carried out by fluid catalytic cracking of vacuum gas, and in recent years, a metathesis reaction based on ethylene and 2-butene and having 4 or more carbon atoms. Contact cracking of olefins, as well as so-called MTO processes (processes for producing olefins from methanol) based on at least one of methanol and dimethyl ether, are also attracting attention. In addition, a method of producing propylene by reacting at least one of olefins with methanol and dimethyl ether is also known. Examples of using olefins having 4 or more carbon atoms (Patent Document 1) or examples using ethylene (Patent Document 2) Is disclosed.

Patent Document 1: US Patent No. 6888038

Patent Document 2: WO2005 / 056504

On the other hand, the method of dimerizing ethylene is also disclosed as a method of manufacturing butene (nonpatent literature 1, 2).

Non-Patent Document 1: Catalysis Today, 14, (1992) 28

Non-Patent Document 2: Industrial Chemistry Magazine, Vol. 66, No. 7 (1963) 973

Disclosure of Invention

Problems to be Solved by the Invention

In the above propylene manufacturing method, the steam cracking method has become the mainstream in the world, but there is a limit in changing the yield balance of both according to the change in the supply and demand balance of ethylene and propylene.

When the ratio of propylene demand to ethylene demand increases, a propylene production method is effective, and as one example thereof, a method of producing propylene by reacting at least one of ethylene, methanol and dimethyl ether described above is mentioned. Can be.

However, as a result of examining the reaction of ethylene with at least one of methanol and dimethyl ether, the present inventors have found that a large amount of olefins having 4 or more carbon atoms is produced under the reaction conditions capable of increasing the conversion of ethylene, thereby obtaining a high propylene selectivity. It was found out. On the other hand, in the reaction conditions in which propylene can be obtained in a highly selective manner, since the conversion ratio of ethylene is low, it has been found that the weight ratio of ethylene / propylene at the reactor outlet becomes very large (normally, the weight ratio of ethylene / propylene is 2.0 or more). In this case, since a large amount of unreacted ethylene needs to be recycled to the reactor, there is a problem that the installation cost and the service cost become very large.

An object of the present invention is to provide a novel process in which propylene, at least one of methanol and dimethyl ether is used as a raw material, and which has a low recycling amount of unreacted ethylene and a low equipment cost and a service cost. .

Means to solve the problem

The inventors have diligently studied how to produce propylene by reacting at least one of olefins having 4 or more carbon atoms with methanol and dimethyl ether. When at least one of methanol and dimethyl ether was reacted with the conversion to hydrocarbon, it was found that the olefin conversion of the raw material was improved as compared with the case where at least one of ethylene, methanol and dimethyl ether was reacted. At this time, in addition to propylene, ethylene is also by-produced, but the ethylene / propylene weight ratio at the reactor outlet is significantly less than 2.0. Therefore, it was found that the recycling amount of ethylene to the reactor can be significantly reduced, thereby reducing the equipment cost and the service cost.

In addition, the present inventors earnestly examined a method of reducing the amount of recycled ethylene, and as a result, at least one of ethylene, methanol and dimethyl ether was reacted under specific reaction conditions to obtain a fluid containing propylene and an olefin having 4 or more carbon atoms. It has been found that propylene can be produced at a high selectivity while reducing the amount of ethylene recycled by reacting at least a part of the olefins having 4 or more carbon atoms contained in the fluid with at least one of methanol and dimethyl ether.

The present invention has been accomplished based on these findings, and the gist thereof is as follows.

[1] A method for producing propylene using ethylene as a raw material or at least one of ethylene, methanol and dimethyl ether as raw materials

The raw material is reacted in the first reactor in the presence of the first catalyst to obtain a fluid (X) containing olefins having 4 or more carbon atoms,

A method for producing propylene, wherein a fluid containing propylene is obtained by reacting at least a portion of the fluid (X) with at least one of methanol and dimethyl ether in a second reactor in the presence of a second catalyst.

[2] A process for producing propylene using ethylene, at least one of methanol and dimethyl ether as a raw material, wherein ethylene is reacted with at least one of methanol and dimethyl ether in a first reactor in the presence of a first catalyst to produce propylene. And after obtaining a fluid (A) containing olefins having 4 or more carbon atoms, at least a part of the olefins having 4 or more carbon atoms contained in the fluid (A) and at least one of methanol and dimethyl ether are added in the presence of a second catalyst. Propylene is obtained by reacting in two reactors.

[3] The method for producing propylene according to [2], which comprises a process including the following steps (1A), (2A), (3A), (4A), and (5A).

Step (1A): Propylene, carbon number 4, by supplying at least one of ethylene as a raw material, methanol and dimethyl ether as a raw material, and the fluid (F) recycled from step (4A) to the first reactor and contacting with the first catalyst. Process of obtaining the fluid (A) containing the fluid containing the above olefin, ethylene, paraffin, aromatic compound, and water

Step (2A): Propylene, olefins having 4 or more carbon atoms, and ethylene by supplying at least one of methanol and dimethyl ether as raw materials and the fluid (G) recycled from step (5A) into a second reactor and contacting with a second catalyst. To obtain a fluid (B) containing water, paraffin, aromatic compounds and water

Process (3A): The fluid (C) which mixed the said fluid (A) and the said fluid (B) is a fluid rich in C2 or less hydrocarbon (D), a propylene rich fluid, and a C4 or more hydrocarbon rich Process of separating into fluid (E) and fluid rich in water

Step (4A): a step of recycling some of the fluid (F) of the fluid (D) to the first reactor and drawing out the remaining fluid from the process

Step (5A): a step of recycling a part of the fluid (G) of the fluid (E) to the second reactor and drawing out the remaining fluid from the process.

[4] The method for producing propylene according to [3], wherein the amount of ethylene contained in the fluid (C) is less than 2.0 by weight relative to propylene contained in the fluid.

[5] The method for producing propylene according to [2], which comprises a process including the following steps (1B), (2B), (3B), (4B), and (5B).

Step (1B): Propylene, carbon number 4 is obtained by supplying at least one of ethylene as a raw material, methanol and dimethyl ether as a raw material, and the fluid L recycled from step (4B) to a first reactor and contacting the first catalyst. Process of obtaining the fluid (A) containing the fluid containing the above olefin, ethylene, paraffin, aromatic compound, and water

Step (2B): propylene, by feeding the fluid (A), at least one of methanol and dimethyl ether as raw materials, and the recycled fluid (M) from step (5B) into a second reactor and contacting with a second catalyst. Obtaining fluid (I) containing olefins having 4 or more carbon atoms, ethylene, paraffins, aromatic compounds and water

Step (3B): Separating the fluid (I) into a hydrocarbon-rich fluid (J) having a carbon number of 2 or less, a propylene-rich fluid, a fluid having a hydrocarbon of 4 or more carbon atoms (K), and a fluid rich in water. fair

Step (4B): a step of recycling some fluid L of the fluid J to the first reactor, and extracting the remaining fluid from the process

Step (5B): a step of recycling a part of the fluid K of the fluid K to the second reactor and extracting the remaining fluid from the process.

[6] The method for producing propylene according to [5], wherein the amount of ethylene contained in the fluid (I) is less than 2.0 by weight relative to propylene contained in the fluid.

[7] The method for producing propylene according to any one of [1] to [6], wherein a fluid containing an olefin having at least 4 carbon atoms is supplied to the second reactor from outside the process.

[8] The method for producing propylene according to any one of [1] to [7], wherein the temperature of the first reactor outlet is lower than the temperature of the second reactor outlet.

[9] The method for producing propylene according to any one of [1] to [8], wherein the conversion ratio of ethylene in the first reactor calculated by the following formula is 30% or more.

Ethylene conversion rate (%) = {(ethylene flow rate at the first reactor inlet-ethylene flow rate at the first reactor outlet) / ethylene flow rate at the first reactor inlet} × 100

[10] A process for producing propylene from ethylene and at least one of methanol and dimethyl ether, wherein at least one of methanol and dimethyl ether is reacted with an olefin having 4 carbon atoms obtained by dimerization reaction of ethylene. Propylene manufacturing method comprising a.

[11] The method for producing propylene according to [10], which comprises a process including the following steps (1C), (2C), (3C), (4C), and (5C).

Step (1C): a step of obtaining a fluid (Q) containing an olefin having 4 carbon atoms by supplying ethylene as a raw material and the fluid P recycled from the step (4C) to the first reactor and contacting with an ethylene dimerization catalyst.

Step (2C): by supplying fluid Q from step (1C), fluid R recycled from step (5C), at least one of methanol and dimethyl ether to a second reactor and contacting with a propylene production catalyst To obtain a fluid (S) containing propylene, ethylene, other olefins, paraffins, aromatic compounds and water

Process (3C): The fluid (S) from the process (2C) includes a fluid (T) rich in hydrocarbons having 2 or less carbon atoms, a fluid rich in propylene, a fluid (U) rich in hydrocarbons having 4 or more carbon atoms, and water. Process to separate into abundant fluid

Step (4C): a step of recycling some of the fluid P of the fluid T from the step 3C to the first reactor, and extracting the remaining fluid from the process

Process (5C): The process of recycling some fluid R of the fluid U from process (3C) to a 2nd reactor, and extracting the remaining fluid from the process.

[12] The method for producing propylene according to [11], wherein a part of the fluid Q is extracted outside the process without being supplied to the second reactor in the process (2C).

[13] The method for producing propylene according to [11] or [12], wherein a fluid containing an olefin having at least 4 carbon atoms is supplied to the second reactor from outside the process.

[14] The propylene according to any one of [10] to [13], wherein the amount of ethylene contained in the fluid (S) is less than 2.0 by weight relative to the propylene contained in the fluid (S). Manufacturing method.

Effects of the Invention

According to the present invention, a process for producing propylene using ethylene, at least one of methanol and dimethyl ether as a raw material, and having a low recycling amount of ethylene and having a low equipment cost and a service cost can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a system diagram which shows an example of embodiment of the propylene manufacturing method of this invention.

2 is a system diagram showing another example of the embodiment of the propylene production method of the present invention.

3 is a system diagram showing another example of the embodiment of the propylene production method of the present invention.

4 is a system diagram showing a propylene production method of a comparative example.

(Explanation of the sign)

10: first reactor

20: second reactor

30: Separation Purification System

13: first reactor

23: second reactor

33: Separation Purification System

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Hereinafter, although the typical aspect for implementing this invention is demonstrated concretely, this invention is not limited to the following aspect, unless the summary is exceeded.

The method for producing propylene of the present invention is a method for producing propylene using ethylene as a raw material or at least one of ethylene, methanol and dimethyl ether as a raw material,

The raw material is reacted in the first reactor in the presence of the first catalyst to obtain a fluid (X) containing olefins having 4 or more carbon atoms,

At least part of the fluid (X) and at least one of methanol and dimethyl ether are reacted in a second reactor in the presence of a second catalyst to obtain a fluid containing propylene. Specifically, the following 1st-3rd aspect is mentioned.

The method for producing propylene of the present invention is a method for producing propylene using at least one of ethylene, methanol and dimethyl ether as a raw material, in the presence of a first catalyst, at least one of ethylene, methanol and dimethyl ether in a first reactor. After reacting one to obtain a fluid (A) containing propylene and an olefin having 4 or more carbon atoms, at least a part of the olefin having 4 or more carbon atoms contained in the fluid (A) and at least one of methanol and dimethyl ether are added to the second catalyst. Propylene is obtained by reacting in a second reactor in the presence, and is preferably a process comprising the following five steps (1A), (2A), (3A), (4A) and (5A). (Hereinafter, it may be called "the 1st aspect.") Or the process containing process (1B), (2B), (3B), (4B), and (5B) (henceforth "a 2nd aspect". There is a case.) Is done.

As a first aspect

Step (1A): Propylene, carbon number 4, by supplying at least one of ethylene as a raw material, methanol and dimethyl ether as a raw material, and the fluid (F) recycled from step (4A) to the first reactor and contacting with the first catalyst. Process of obtaining the fluid (A) containing the fluid containing the above olefin, ethylene, paraffin, aromatic compound, and water

Step (2A): Propylene, olefins having 4 or more carbon atoms, and ethylene by supplying at least one of methanol and dimethyl ether as raw materials and the fluid (G) recycled from step (5A) into a second reactor and contacting with a second catalyst. To obtain a fluid (B) containing water, paraffin, aromatic compounds and water

Process (3A): The fluid (C) which mixed the said fluid (A) and the said fluid (B) is a fluid rich in C2 or less hydrocarbon (D), a propylene rich fluid, and a C4 or more hydrocarbon rich Process of separating into fluid (E) and fluid rich in water

Step (4A): a step of recycling some of the fluid (F) of the fluid (D) to the first reactor and drawing out the remaining fluid from the process

Step 5A: recycling a part of the fluid G of the fluid E to the second reactor and extracting the remaining fluid from the process

As a second aspect

Step (1B): Propylene, carbon number 4 is obtained by supplying at least one of ethylene as a raw material, methanol and dimethyl ether as a raw material, and the fluid L recycled from step (4B) to a first reactor and contacting the first catalyst. Process of obtaining the fluid (A) containing the fluid containing the above olefin, ethylene, paraffin, aromatic compound, and water

Step (2B): propylene, by feeding the fluid (A), at least one of methanol and dimethyl ether as raw materials, and the recycled fluid (M) from step (5B) into a second reactor and contacting with a second catalyst. Obtaining fluid (I) containing olefins having 4 or more carbon atoms, ethylene, paraffins, aromatic compounds and water

Step (3B): Separating the fluid (I) into a hydrocarbon-rich fluid (J) having a carbon number of 2 or less, a propylene-rich fluid, a fluid having a hydrocarbon of 4 or more carbon atoms (K), and a fluid rich in water. fair

Step (4B): a step of recycling some fluid L of the fluid J to the first reactor, and extracting the remaining fluid from the process

Step 5B: a step of recycling a part of the fluid K of the fluid K to the second reactor and extracting the remaining fluid from the process

In addition, in this invention, "rich" means that the purity of a target object is 50 mol% or more, Preferably it is 70 mol% or more, More preferably, it is 90 mol% or more, More preferably, it is 95 mol% or more. For example, "the fluid (E) rich in hydrocarbons having 4 or more carbon atoms" means 50 mol% or more, preferably 70 mol% or more, more preferably 90 mol% or more, and even more preferably "hydrocarbons having 4 or more carbon atoms". Is a fluid containing 95 mol% or more.

In this invention, "outgoing from the process" means that neither of the 1st reactor and the 2nd reactor of this process is recycled.

Moreover, this invention, Preferably, the above-mentioned five process (1A), (2A), (3A), (4A) and (5A), or process (1B), (2B), (3B), ( Although 4B) and (5B) are included, other processes may exist before and after five processes, without precluding the existence of other processes, as long as the objective of solving the subject of this invention is solved. Another process may exist in between.

In a third aspect, a process for producing propylene using at least one of ethylene, methanol, and dimethyl ether as a raw material, comprising: reacting at least one of methanol and dimethyl ether with an olefin having 4 carbon atoms obtained by dimerization reaction of ethylene Although it contains, Preferably, it consists of the process containing the following five processes (1C), (2C), (3C), (4C), and (5C).

Step (1C): a step of obtaining a fluid (Q) containing an olefin having 4 carbon atoms by supplying ethylene as a raw material and the fluid P recycled from the step (4C) to the first reactor and contacting with an ethylene dimerization catalyst.

Step (2C): by supplying fluid Q from step (1C), fluid R recycled from step (5C), at least one of methanol and dimethyl ether to a second reactor and contacting with a propylene production catalyst To obtain a fluid (S) containing propylene, ethylene, other olefins, paraffins, aromatic compounds and water

Process (3C): The fluid (S) from the process (2C) includes a fluid (T) rich in hydrocarbons having 2 or less carbon atoms, a fluid rich in propylene, a fluid (U) rich in hydrocarbons having 4 or more carbon atoms, and water. Process to separate into abundant fluid

Step (4C): a step of recycling some of the fluid P of the fluid T from the step 3C to the first reactor, and extracting the remaining fluid from the process

Step (5C): a step of recycling some fluid R of the fluid U from the step (3C) to the second reactor and drawing out the remaining fluid from the process

In addition, in this invention, "rich" means that the purity of a target object is 50 mol% or more, Preferably it is 70 mol% or more, More preferably, it is 90 mol% or more, More preferably, it is 95 mol% or more. For example, "the fluid rich in hydrocarbons having 4 or more carbon atoms (F)" means 50 mol% or more, preferably 70 mol% or more, more preferably 90 mol% or more, and even more preferably "hydrocarbons having 4 or more carbon atoms". Is a fluid containing 95 mol% or more.

In this invention, "outgoing from the process" means that neither of the 1st reactor and the 2nd reactor of this process is recycled.

In addition, the present invention preferably includes the above-mentioned five steps (1C), (2C), (3C), (4C) and (5C), but as long as the object of the present invention is solved, Instead of excluding the existence of other processes, other processes may exist before and after the five processes, and other processes may exist between the respective processes.

In the following, the propylene production method of the present invention will be described according to the above.

{First Aspect}

First, the process (1A)-(5A) of a 1st aspect is demonstrated.

[Description of Step (1A)]

In step (1A), propylene and carbon number are obtained by supplying at least one of ethylene as a raw material, methanol and dimethyl ether as a raw material, and the fluid (F) recycled from step (4A) to the first reactor and contacting with the first catalyst. A fluid (A) containing a fluid containing at least 4 olefins, ethylene, paraffins, aromatic compounds and water is obtained.

<First catalyst>

 The "first catalyst" used in the first embodiment refers to a catalyst used in the first reactor, and refers to a catalyst capable of producing propylene and an olefin having 4 or more carbon by reacting ethylene with at least one of methanol and dimethyl ether.

As a catalyst used for this reaction, if it is a solid thing which has Bronsted acid point, it will not specifically limit, A conventionally well-known catalyst is used, For example, Clay minerals, such as kaolin; Impregnated and supported with acids such as sulfuric acid and phosphoric acid in a carrier such as clay mineral; Acidic ion exchange resins; Zeolites; Aluminum phosphates; And solid acid catalysts such as mesoporous silica alumina such as Al-MCM41.

Among these solid acid catalysts, those having a molecular sieve effect are preferable, and those having a low acid strength are preferred.

As the structures of the zeolites and aluminum phosphates having the molecular sieve effect among the solid acid catalysts, represented by codes prescribed by the International Zeolite Association (IZA), for example, AEI, AET, AEL, AFI, AFO, AFS, AST , ATN, BEA, CAN, CHA, EMT, ERI, EUO, FAU, FER, LEV, LTL, MAZ, MEL, MFI, MOR, MTT, MTW, MWW, OFF, PAU, RHO, STT, TON have. Among these, catalysts having a framework density of 18.0 T / nm ³ or less are preferred, and such catalysts are preferably MFI, MEL, MOR, MWW, FAU, BEA, CHA, and more preferably MFI, MEL, MOR. , MWW, CHA, and particularly preferably MFI, MEL, MWW, CHA.

Here, the framework density (unit: T / nm ³ ) means the number of T atoms (atoms other than oxygen among the atoms constituting the skeleton of the zeolite) per unit volume (1 nm ³ ) of the zeolite, This value is determined by the structure of the zeolite.

More preferably, the solid acid catalyst has micropores having a pore diameter of 0.3 to 0.9 nm, a crystalline alumino having a BET specific surface area of 200 to 700 m 2 / g and a pore volume of 0.1 to 0.5 g / ml. Silicates, metalosilicates or crystalline aluminum phosphates are preferred. In addition, the pore diameter here refers to the crystallographic free diameter of the channels defined by the International Zeolite Association (IZA), and when the shape of the pores (channels) is a round shape, it refers to the diameter. If the shape of oval refers to a short diameter (短 徑).

During the addition, the aluminosilicate, preferably at least a molar ratio of _{SiO 2 / Al 2 O 3 10} . If the SiO ₂ / Al ₂ O ₃ molar ratio is too low, it is not preferable because 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, it is not preferable because the catalytic activity is lowered. The molar ratio can be obtained by conventional methods such as fluorescence X-rays and chemical analysis.

The aluminum content in the catalyst can be controlled by the amount of raw material injected during 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 other elements, such as boron and gallium, and it is preferable to substitute with boron especially.

These catalysts may be used individually by 1 type, and may mix and use 2 or more types.

In this invention, you may granulate and shape | mold using the substance and binder which are inert to reaction, or may mix and use these for reaction. Examples of the substance or binder inert to the reaction include alumina or alumina sol, silica, silica gel, quartz and mixtures thereof.

The above catalyst composition is a composition only of the catalytically active component which does not contain a substance, a binder, or the like which is inert to such a reaction. However, when the catalyst according to the present invention contains a substance, a binder, or the like which is inert to such a reaction, the above-mentioned catalytically active component and a substance, a binder or the like which are inert to such a reaction are called a catalyst and are inert to such a reaction. When it does not contain a substance, a binder, etc., it calls only a catalyst active component.

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 µm to 500 µm as an average particle diameter. If the particle size of the catalyst is too large, the surface area showing the catalytic activity is small, and if the particle size is too small, the handleability is poor, which is not preferable in either case. This average particle diameter can be calculated | required by SEM observation etc.

The preparation method of the catalyst used by this invention is not specifically limited, It can be prepared by the well-known method generally called hydrothermal synthesis. In addition, after hydrothermal synthesis, the composition may be changed by modification such as ion exchange, dealumination treatment, impregnation, or supporting.

When used for the reaction, the catalyst used in the present invention may be one having the above-described physical properties or composition, and may be prepared by any method.

<Reaction raw material>

It does not specifically limit as ethylene used as a reaction raw material. For example, those produced by catalytic cracking or steam cracking from petroleum feedstocks, obtained by conducting FT (Fischer Tropsch) synthesis using hydrogen / CO mixed gas obtained by gasification of coal as a raw material, dehydrogenation of ethane By various methods known in the art, such as those obtained by the method or by the oxidative dehydrogenation method, those obtained by the metathesis reaction and homologation reaction of propylene, those obtained by the MTO reaction, and those obtained by the dehydration reaction of ethanol. What is obtained can be used arbitrarily, At this time, what is in the state in which compounds other than ethylene originating in each manufacturing method were mixed arbitrarily may be used as it is, and purified ethylene may be used.

In addition, the origin of manufacture of at least one of methanol and dimethyl ether used as a raw material for the reaction is not particularly limited. For example, those obtained by hydrogenation of a mixed gas of coal and natural gas and hydrogen / CO derived from by-products in the steelmaking industry, those obtained by the reforming reaction of alcohols derived from plants, and those obtained by the fermentation method. And those obtained from organic materials such as recycled plastics and municipal wastes. Under the present circumstances, the thing of the state which arbitrarily mixed compounds other than methanol and dimethyl ether resulting from each manufacturing method may be used as it is, or the refined thing may be used.

<Fluid (F) Recycled from Step (4A)>

The "fluid (F) recycled from process (4A)" means the recycle fluid (F) obtained by process (4A), and is a fluid containing ethylene. This fluid (F) is a part of fluid (D) rich in hydrocarbons having 2 or less carbon atoms in step (3A). "Partial" here is normally the range of 10 to 99 weight% in the flow volume of the fluid (D), Preferably it is the range of 50 to 95 weight%. If it is lower than this range, there arises a problem that the flow rate of ethylene supplied to the first reactor as a new raw material increases, whereas if it exceeds this range, methane or ethane accumulates in the first reactor and recycle fluid. It is not preferable because it is.

The fluid F recycled to the first reactor may contain a compound that does not participate in a reaction such as methane or ethane.

<First reactor>

It is a gas phase reaction performed in a 1st reactor. Although there is no restriction | limiting in particular in the form of this gas phase reactor, Usually, it selects from a continuous fixed bed reactor or a fluidized bed reactor. Preferably it is a fixed bed reactor. In addition, in the case of filling the above-mentioned catalyst in the fixed bed reactor, in order to suppress the temperature distribution of the catalyst layer small, granular materials inert to the reaction of quartz sand, alumina, silica, silica-alumina and the like may be mixed with the catalyst and filled. In this case, the amount of the granular material inert to the reaction of quartz sand or the like is not particularly limited. Moreover, it is preferable that this granular material is the particle size of the grade similar to a catalyst from a uniform mixing property with a catalyst.

<Reaction conditions>

The lower limit of the reaction temperature is usually about 300 ° C. or higher, preferably 400 ° C. or higher as the gas temperature at the inlet of the first reactor, and the upper limit of the reaction temperature is usually 600 ° C. or lower, preferably 500 ° C. or lower. When reaction temperature is too low, reaction rate is low, there exists a tendency for many unreacted raw materials to remain, and the yield of propylene also falls. On the other hand, when reaction temperature is too high, since the yield of propylene falls markedly and the conversion of ethylene tends to fall, it is unpreferable.

Moreover, it is preferable that the temperature of a 1st reactor outlet is lower than the temperature of the 2nd reactor outlet in a process (2A) and / or a process (2B) mentioned later, and the temperature of a 1st reactor outlet is the temperature of a 2nd reactor outlet. It is further more preferable that it is 50 degreeC or more, for example, about 50-200 degreeC lower. By operating the first reactor and the second reactor under such temperature conditions, it becomes possible to obtain propylene highly selectively under the condition of reducing the recycle amount of ethylene.

The upper limit of the reaction pressure is usually 2 MPa (absolute pressure, the same below), preferably 1 MPa or less, and more preferably 0.7 MPa or less. In addition, the minimum of reaction pressure is although it does not restrict | limit especially, Usually, it is 1 kPa or more, Preferably it is 50 kPa or more. When the reaction pressure is too high, the amount of undesirable byproducts 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 slow.

The amount of ethylene supplied to the first reactor is 0.2 or more, preferably 0.5 or more, 5 or less, preferably 2 or less in molar ratio with respect to the sum of the number of moles of methanol and twice the number of moles of dimethyl ether supplied to the reactor. It is as follows.

That is, when the supply molar amount of ethylene is Met, the supply molar amount of methanol is Mm, and the supply molar amount of dimethyl ether is Mdm, Met is 0.2-5 times (Mm + 2Mdm), Preferably it is 0.5-2 times.

Even if this feed concentration ratio is too low or too high, reaction will become slow and it is unpreferable. Especially, when this feed concentration ratio is too high, it is unpreferable because ethylene at a reactor outlet increases and recycle flow volume increases.

Here, the supply concentration ratio can be known by quantifying the composition of each of the fluids supplied to the reactor or the mixed fluids by general analytical methods such as gas chromatography.

In addition, when supplying at least one of ethylene, methanol, and dimethyl ether to a reactor, these may be supplied separately, and may be supplied after mixing some or all previously.

The total concentration (substrate concentration) of ethylene, methanol, and dimethyl ether in the total feed components supplied to the first reactor is 20% by volume or more and 80% by volume or less, preferably 30% by volume or more and 70% by volume or less in total. to be.

The substrate concentration can be found by quantifying the composition of each fluid supplied to the first reactor or the mixed fluid by general analytical methods such as gas chromatography.

When the substrate concentration is too high, the production of aromatic compounds and paraffins becomes remarkable, and the selectivity of propylene tends to decrease. On the contrary, when the substrate concentration is too low, a large amount of catalyst is required because the reaction rate is slowed, and the cost of purifying the product and the construction cost of the reaction equipment are also uneconomical.

Therefore, the reaction substrate is diluted with the dilution gas described later to achieve such a substrate concentration. As a method of controlling a substrate concentration, the method of controlling the flow volume of the fluid discharged | emitted from a process is mentioned. By changing the flow rate of the fluid discharged from the process, it is possible to change the flow rate of the dilution gas recycled to the first reactor, thereby changing the substrate concentration.

In the first reactor, in addition to at least one of ethylene, methanol and dimethyl ether, gas inert to the reaction may be present, such as paraffins, aromatics, water vapor, carbon dioxide, carbon monoxide, nitrogen, argon, helium, and mixtures thereof. Can be. Moreover, among these diluent gases, although paraffins and aromatics may react slightly depending on reaction conditions, they are defined as diluent gas from the point that reaction amount is small.

As such a dilution gas, the impurity contained in the reaction raw material may be used as it is, or the dilution gas prepared separately may be mixed with the reaction raw material and used.

In addition, before diluting gas into a 1st reactor, you may mix with a reaction raw material, and you may supply to a 1st reactor separately from reaction raw material.

The space velocity is preferably between 0.1Hr 500Hr ^-1 to ^-1, and it is even more preferable between ^-1 to 1.0Hr 100Hr ^-1. If the space velocity is too high, the conversion of at least one of ethylene, methanol and dimethyl ether as raw materials is lowered. In addition, when the space velocity is too low, the amount of catalyst required to obtain a constant production amount increases, and the first reactor becomes too large, and undesirable by-products such as aromatic compounds and paraffin are produced, which is not preferable. In addition, the space velocity here is the flow rate of ethylene which is a reaction raw material with respect to the weight per weight of a catalyst (catalyst active component), and the weight of a catalyst here is catalyst activity which does not contain the inert component and binder which are used for granulation and shaping | molding of a catalyst. The weight of the component. Further, the flow rate is the flow rate (weight / hour) of ethylene.

<Consumption of Raw Material by Reaction>

Regarding the sum of the molar flow rate of methanol supplied to the first reactor and twice the molar flow rate of dimethyl ether, the sum of the molar flow rate of methanol at the outlet of the first reactor and twice the molar flow rate of dimethyl ether is less than 1%. This is preferred. More preferably less than 0.1%. If the consumption is small and the amount of methanol and dimethyl ether at the outlet of the first reactor is excessively increased, purification of the product olefin becomes difficult. As a method of increasing a consumption amount, the method of raising reaction temperature or decreasing space velocity is mentioned.

Here, the flow rates of methanol, dimethyl ether, and ethylene supplied to the first reactor are quantified by the general analytical methods such as gas chromatography to determine the composition of each fluid or mixed fluid to be supplied to the first reactor. The flow rate of methanol, dimethyl ether and ethylene at the first reactor outlet can be determined by measuring the flow rate, and the composition of the first reactor outlet fluid is quantified by a general method such as gas chromatography to determine the flow rate of the first reactor outlet fluid. It can be known by measuring or calculating.

The conversion of ethylene in the first reactor is usually 30% or more, preferably 40% or more and less than 80%. When the conversion ratio of ethylene is less than this range, unreacted olefin increases, and since the flow volume of the fluid recycled to a 1st reactor becomes large too large, it is unpreferable. On the other hand, if it exceeds this range, since undesirable compounds, such as a paraffin and an aromatic compound, are byproduced, it is not preferable.

In addition, the "conversion ratio of ethylene" used in this invention means the ratio by which ethylene is converted into compounds other than ethylene, and is represented by following Formula.

Ethylene conversion rate (%) = {(ethylene flow rate at the first reactor inlet-ethylene flow rate at the first reactor outlet) / ethylene flow rate at the first reactor inlet} × 100

Moreover, the conversion rate of ethylene can be quantified by general analytical methods, such as gas chromatography, and a flowmeter.

<Fluid (A) containing propylene, olefins having 4 or more carbon atoms, ethylene, paraffins, aromatic compounds and water>

"The fluid (A) containing the fluid containing propylene, a C4 or more olefin, ethylene, a paraffin, an aromatic compound, and water" means the fluid of the exit of a 1st reactor.

As a 1st reactor outlet fluid (A), the mixed gas containing propylene which is a reaction product, unreacted raw material, by-product, and diluent is obtained. The propylene concentration in the mixed gas is usually 5 to 95% by weight.

Unreacted raw material is ethylene normally. Depending on the reaction conditions, at least one of methanol and dimethyl ether is included, but the reaction is preferably carried out under reaction conditions in which at least one of methanol and dimethyl ether does not remain. This facilitates separation of the reaction product and the unreacted raw material. Examples of the product include olefins, paraffins, aromatic compounds and water having 4 or more carbon atoms in addition to propylene.

[Description of Step (2A)]

In step (2A), propylene, an olefin having 4 or more carbon atoms, by supplying at least one of methanol and dimethyl ether as raw materials and the fluid (G) recycled from step (5A) to a second reactor and contacting with a second catalyst, A fluid (B) containing ethylene, paraffins, aromatic compounds and water is obtained.

<Second catalyst>

The "second catalyst" refers to a catalyst used in the second reactor, and means a catalyst capable of producing propylene and an olefin having 4 or more carbons by reacting methanol and / or dimethyl ether with an olefin having 4 or more carbon atoms.

As a catalyst used as a 2nd catalyst, the thing as described in "the 1st catalyst" in the above-mentioned [explanation of process (1A)] can be used. In this case, as the second catalyst, a catalyst having the same structure and composition as that used as the first catalyst may be used, or a catalyst having a different structure and / or different composition may be used. When using catalysts of different compositions, it is preferable that the SiO ₂ / Al ₂ O ₃ molar ratio of the second catalyst is higher than the SiO ₂ / Al ₂ O ₃ molar ratio of the first catalyst. Since the higher the molar ratio of SiO ₂ / Al ₂ O ₃ , the more the production of paraffins and aromatics is suppressed, the higher the molar ratio of SiO ₂ / Al ₂ O ₃ is, but the higher the molar ratio of SiO ₂ / Al ₂ O ₃ of the first catalyst is. It is because there exists a tendency for the conversion rate of ethylene to become low too high.

<Reaction raw material>

The origin of manufacture of at least one of methanol and dimethyl ether used as the reaction raw material is not particularly limited. For example, those obtained by hydrogenation of a mixed gas of coal and natural gas and hydrogen / CO derived from by-products in the steelmaking industry, those obtained by the reforming reaction of alcohols derived from plants, and those obtained by the fermentation method. And those obtained from organic materials such as recycled plastics and municipal wastes. Under the present circumstances, the thing of the state which arbitrarily mixed compounds other than methanol and dimethyl ether resulting from each manufacturing method may be used as it is, or the refined thing may be used.

<Fluid G Recycled from Step (5A)>

The "fluid G recycled from process (5A)" means the recycle fluid (G) obtained by process (5A). Fluid G contains a hydrocarbon having 4 or more carbon atoms. This fluid (G) is a part of fluid (E) rich in C4 or more hydrocarbons in process (3A). "Partial" here is normally the range of 10-99 weight% in the flow volume of the fluid (E), Preferably it is the range of 50-95 weight%. Below this range, there is a problem that the amount of olefin recycled to the reactor decreases and the propylene yield is lowered. If the range exceeds this range, paraffin contained in the fluid (E) accumulates, and fluids (B) and (C ) And (G) are not preferable because of the problem that the flow rate increases, resulting in an increase in facility cost and service cost.

The fluid (G) rich in hydrocarbons having 4 or more carbon atoms to be recycled to the second reactor is not particularly limited as long as it contains olefins, and may contain paraffins or aromatic compounds.

<Second reactor>

What is done in the second reactor is a gas phase reaction. Although there is no restriction | limiting in particular in the form of this gas phase reactor, Usually, it selects from a continuous fixed bed reactor or a fluidized bed reactor. Preferably it is a fixed bed reactor. In addition, in the case of filling the above-mentioned catalyst in the fixed bed reactor, in order to suppress the temperature distribution of the catalyst layer small, granular materials inert to the reaction of quartz sand, alumina, silica, silica-alumina and the like may be mixed with the catalyst and filled. In this case, the amount of the granular material inert to the reaction of quartz sand or the like is not particularly limited. Moreover, it is preferable that this granular material is the particle size of the same grade as a catalyst from a uniform mixing property with a catalyst.

<Reaction conditions>

The lower limit of the reaction temperature is usually about 300 ° C. or higher, preferably 400 ° C. or higher as the gas temperature at the inlet of the second reactor, and the upper limit of the reaction temperature is usually 700 ° C. or lower, preferably 600 ° C. or lower. If the reaction temperature is too low, the reaction rate is low, there is a tendency for a large number of unreacted raw materials to remain, and the yield of propylene also decreases. On the other hand, when reaction temperature is too high, the yield of propylene will fall remarkably.

The upper limit of the reaction pressure is usually 2 MPa (absolute pressure, the same below) or less, preferably 1 MPa or less, and more preferably 0.7 MPa or less. In addition, the minimum of reaction pressure is although it does not restrict | limit especially, Usually, it is 1 kPa or more, Preferably it is 50 kPa or more. When the reaction pressure is too 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 slow.

The amount of olefins having 4 or more carbon atoms to be supplied to the second reactor is 0.2 or more, preferably 0.5 or more and 10 or less in molar ratio with respect to the sum of the number of moles of methanol and two times the number of moles of dimethyl ether supplied to the second reactor. , Preferably it is 5 or less.

That is, Mc4 is 0.2 to 10 times of (Mm + 2Mdm), Preferably it is 0.5 to 5 times when supply molar amount of a C4 or more olefin is Mc4, M1 supply methanol has Mm, and dimethyl ether supply molar amount is Mdm.

Even if this feed concentration ratio is too low or too high, reaction will become slow and it is unpreferable. Especially, when this feed concentration ratio is too low, since the consumption of olefin which is a raw material reduces, it is unpreferable.

Here, the supply concentration ratio can be known by quantifying the composition of each fluid to be supplied to the second reactor or the mixed fluid by general analytical methods such as gas chromatography.

Moreover, when supplying a C4 or more olefin, at least one of methanol, and a dimethyl ether to a 2nd reactor, these may be supplied separately, and you may supply, after mixing part or all previously.

The total concentration (substrate concentration) of olefins having 4 or more carbon atoms, methanol and dimethyl ether in the total feed components supplied to the second reactor is 20% by volume or more and 80% by volume or less, preferably 30% by volume or more in total 70 It is volume% or less.

The substrate concentration can be found by quantifying the composition of each fluid to be supplied to the second reactor or the mixed fluid by general analytical methods such as gas chromatography.

When the substrate concentration is too high, the production of aromatic compounds and paraffins becomes remarkable, and the selectivity of propylene tends to decrease. On the contrary, when the substrate concentration is too low, a large amount of catalyst is required because the reaction rate is slowed, and the cost of purifying the product and the construction cost of the reaction equipment are also uneconomical.

Therefore, the reaction substrate is diluted with the dilution gas described later to achieve such a substrate concentration. As a method of controlling a substrate concentration, the method of controlling the flow volume of the fluid discharged | emitted from a process is mentioned. By changing the flow rate of the fluid discharged from the process, it is possible to change the flow rate of the dilution gas recycled to the second reactor, thereby changing the substrate concentration.

In addition, a butadiene compound may be contained in the hydrocarbon fluid recycled to a 2nd reactor, and / or in the olefin raw material of a C4 or more. As a concentration of butadiene in all the feed components supplied to a 2nd reactor, 2.0 volume% or less is preferable. Here, the butadiene concentration can be known by quantifying the composition of each fluid supplied to the second reactor or the mixed fluid by general analytical methods such as gas chromatography. The higher the butadiene concentration, the faster the deterioration by caulking the catalyst. As a method of decreasing butadiene concentration, the partial hydrogenation method which contacts the fluid with a hydrogenation catalyst and converts into olefins is mentioned.

Moreover, the aromatic compound may be contained in the hydrocarbon fluid recycled to a 2nd reactor. It is preferable that the total amount of the aromatic compound contained in all the gas supplied to a 2nd reactor is less than 0.05 in molar ratio with respect to the total amount of a C4 or more olefin contained in all the gas supplied to a 2nd reactor. Here, ratio of the total amount of the said aromatic compound and the total amount of a C4 or more olefin can be understood by quantifying the composition of each fluid supplied to a 2nd reactor, or the fluid after mixing with general analytical methods, such as gas chromatography.

When the aromatic compound concentration is high, it is not preferable because at least one of the aromatic compound, methanol and dimethyl ether reacts in the second reactor and consumes at least one of methanol and dimethyl ether more than necessary. As a method of reducing the aromatic compound concentration, a separation method by distillation is mentioned.

In the second reactor, a gas inert to the reaction, such as paraffins, aromatics, water vapor, carbon dioxide, carbon monoxide, nitrogen, argon, helium, and mixtures thereof, in addition to olefins having 4 or more carbon atoms and at least one of methanol and dimethyl ether. Can be present. Moreover, among these diluent gases, although paraffins and aromatics may react slightly depending on reaction conditions, they are defined as a dilution gas by the point that reaction amount is small.

As such a dilution gas, the impurity contained in the reaction raw material may be used as it is, or the dilution gas prepared separately may be mixed with the reaction raw material and used.

In addition, before diluting gas into a 2nd reactor, you may mix with a reaction raw material, and you may supply to a 2nd reactor separately from reaction raw material.

The space velocity is preferably between 0.1Hr 500Hr ^-1 to ^-1, and it is even more preferable between ^-1 to 1.0Hr 100Hr ^-1. If the space velocity is too high, the conversion ratio of at least one of olefin, methanol and dimethyl ether as a raw material is low, and sufficient propylene selectivity cannot be obtained. In addition, if the space velocity is too low, the amount of catalyst required to obtain a constant yield increases, the second reactor becomes too large, and undesirable by-products such as aromatic compounds and paraffins are generated, and the propylene selectivity is lowered. Not. In addition, the space velocity here is the flow volume of C4 or more olefin which is a reaction raw material with respect to the weight per weight of catalyst (catalyst active component), and the weight of a catalyst does not contain the inert component and binder used for granulation and shaping | molding of a catalyst here. Not the weight of the catalytically active component. In addition, a flow volume is a flow volume (weight / hour) of an olefin of 4 or more carbon atoms.

<Consumption of Raw Material by Reaction>

Regarding the sum of the molar flow rate of methanol supplied to the second reactor and twice the molar flow rate of dimethyl ether, the sum of the molar flow rate of methanol at the outlet of the second reactor and twice the molar flow rate of dimethyl ether is less than 1%. desirable. More preferably less than 0.1%. If the consumption is small and the amount of methanol and dimethyl ether at the outlet of the second reactor is excessively increased, purification of the product olefin becomes difficult. As a method of increasing a consumption amount, the method of raising reaction temperature or decreasing space velocity is mentioned.

Moreover, as for the sum total of the mole flow rates of a C4 or more olefin to supply to a 2nd reactor, the sum total of the mole flow rates of a C4 or more olefin of a 2nd reactor exit is preferably 20% or more and less than 70%. Preferably it is 25% or more and less than 60%.

If the consumption is too small, the amount of unreacted olefin increases, and the flow rate of the fluid recycled to the second reactor becomes too large, which is not preferable. If the consumption is too large, undesirable compounds such as paraffin and aromatic compounds are by-produced and the propylene yield is lowered, which is not preferable. As a method of adjusting a consumption amount, the method of setting reaction temperature, a space velocity, etc. suitably is mentioned.

Here, the flow rates of methanol, dimethyl ether, and olefins having 4 or more carbon atoms to be supplied to the second reactor are determined by quantifying the composition of each fluid or mixed fluid to be supplied to the second reactor by a general analysis method such as gas chromatography. By measuring the flow rate of the fluid, the flow rate of methanol and dimethyl ether at the second reactor outlet and olefins having 4 or more carbon atoms quantifies the composition of the second reactor outlet fluid by a general method such as gas chromatography, and the second reactor outlet. This can be known by measuring or calculating the flow rate of the fluid.

<Fluid (B) containing propylene, olefins having 4 or more carbon atoms, ethylene, paraffins, aromatic compounds and water>

"Fluid (B) containing propylene, an olefin of 4 or more carbon atoms, ethylene, a paraffin, an aromatic compound, and water" means the fluid of the outlet of a 2nd reactor.

As the second reactor outlet fluid (B), a mixed gas containing propylene as a reaction product, unreacted raw materials, by-products and diluents is obtained. The propylene concentration 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, at least one of methanol and dimethyl ether is included, but the reaction is preferably carried out under reaction conditions in which at least one of methanol and dimethyl ether does not remain. This facilitates separation of the reaction product and the unreacted raw material. Examples of the by-product include ethylene, olefins having 4 or more carbon atoms, paraffins, aromatic compounds, and water.

[Description of Step (3A)]

In the step (3A), the fluid (C) in which the fluid (B) obtained in the step (2A) is mixed is a fluid (D) rich in hydrocarbons having 2 or less carbon atoms, a fluid rich in propylene, a fluid rich in hydrocarbons having 4 or more carbon atoms ( E) and separate into a fluid rich in water.

It is preferable that the quantity of ethylene contained in this mixed fluid (C) is less than 2.0 by weight ratio with respect to the propylene contained in the said fluid, This ratio is more preferably less than 1.5, More preferably, it is less than 1.0. This makes it possible to significantly reduce the installation cost and the service cost of the whole process.

The weight ratio of ethylene and propylene contained in the fluid (C) can be known by quantifying the composition of the fluid by general analytical methods such as gas chromatography.

In addition, the weight ratio of ethylene and propylene of the fluid (C) can be changed by adjusting reaction conditions such as reaction temperature and space velocity of the first reactor and / or the second reactor.

Fluid (C) is a fluid rich in hydrocarbons having 2 or less carbon atoms (D), a fluid rich in propylene, a fluid rich in hydrocarbons having 4 or more carbon atoms (E), and a fluid rich in water by general separation processes such as cooling, compression, and distillation. To be separated. Here, each fluid is not limited to one fluid but may be a plurality of fluids. For example, the fluid (E) rich in hydrocarbons having 2 or less carbon atoms may be one fluid containing methane, ethylene or ethane, or two fluids, a fluid rich in methane and a fluid rich in ethylene and ethane.

Moreover, it is preferable to perform processes, such as quenching, alkali washing, dehydration, as needed. When the oxygen compound is contained in the fluid (C), at least a part of the oxygen compound is removed by the quenching step. When acidic gas, such as carbon dioxide, is contained in a reactor outlet gas, at least a part of acidic gas is removed by alkali washing. Separation of water is possible mainly by condensation by compression and cooling.

The remaining water is preferably removed with an adsorbent such as molecular sieve. The water removed by condensation and / or adsorption may be supplied to wastewater treatment processes such as activated sludge, or may be used as process water or the like. When this process is in the vicinity of the steam cracking process, it is preferable to use as a steam source of a cracker. Moreover, you may recycle to the 1st reactor of process (1A) and / or the 2nd reactor of process (2A), and may use as a dilution gas.

In addition, it is preferable that the obtained propylene-rich fluid further has high purity propylene through a purification step such as distillation. The purity of propylene is 95% or more, preferably 99% or more. More preferably, it is 99.9% or more.

The produced propylene can be used as a raw material for all propylene derivatives generally produced, for example in the production of acrylonitrile by ammoxidation, in the production of acrolein, acrylic acid and acrylic acid esters by selective oxidation, It is applicable to the production of oxo alcohols such as normal butyl alcohol and 2-ethylhexanol, to the production of polypropylene by the polymerization of propylene, and to the production of propylene oxide and propylene glycol by the selective oxidation of propylene. In addition, acetone can be produced by a Wacker reaction, and methyl isobutyl ketone can be produced from acetone. Acetone can also be prepared from acetonecyanhydrin, which is finally converted to methyl methacrylate. Isopropyl alcohol can also be produced by propylene hydration. Moreover, phenol, bisphenol A, and polycarbonate resin can be manufactured from the cumene produced by alkylating benzene as a raw material.

[Description of Step (4A)]

In the step (4A), a part of the fluid (F) of the fluid (D) in the step (3A) is recycled to the first reactor, and the remaining fluid is the process of the present invention (hereinafter referred to as "the present process"). Is available).

At this time, the fluid (D) may be divided into the recycled fluid (F) and the extracted fluid without introducing the fluid (D) into the separation step, but the fluid (D) is introduced into the separation step and has a higher ethylene concentration than the fluid (D). May be recycled to the first reactor. The extracted fluid may be purified in order to recover active ingredients such as ethylene or may be used as a fuel. Moreover, you may use as a raw material of steam cracking.

Moreover, "outgoing from this process" means that neither of the 1st reactor and the 2nd reactor of this process is recycled.

[Description of Step (5A)]

In step 5A, part of the fluid G of the fluid E in step 3A is recycled to the second reactor, and the remaining fluid is taken out from this process. At this time, the fluid (E) may be divided into the recycled fluid (G) and the extracted fluid without introducing the fluid (E) into the separation step, or the fluid (E) is introduced into the separation step to increase the butene concentration than the fluid (E). May be recycled to the second reactor. The extracted fluid may be purified in order to recover active ingredients such as butenes and aromatic compounds, or may be used as fuel. Moreover, you may use as a raw material of steam cracking.

{Second embodiment}

Next, process (1B)-(5B) of a 2nd aspect are demonstrated.

[Description of Step (1B)]

In step (1B), propylene as a raw material, at least one of methanol and dimethyl ether as a raw material, and the fluid (L) recycled from step (4B) are supplied to a first reactor and brought into contact with a first catalyst, thereby producing propylene. And a fluid (A) containing a fluid containing olefins having 4 or more carbon atoms, ethylene, paraffins, aromatic compounds and water.

In this step (1B), <first catalyst>, <reaction raw material>, <first reactor>, <reaction conditions>, <consumption amount of raw material by reaction>, <propylene, olefin having 4 or more carbon atoms, ethylene, paraffin , Fluid (A) containing aromatic compound and water is substantially the same as described in [Description of Step (1A)] in {First Embodiment}.

<Fluid L Recycled from Step (4B)>

The "fluid L recycled from process (4B)" means the recycle fluid (L) obtained by process (4B), and is a fluid containing ethylene. This fluid L is a part of the fluid J rich in hydrocarbons having 2 or less carbon atoms in the step (3B). "Partial" here is normally the range of 10-99 weight% in the flow volume of the fluid J, Preferably it is the range of 50-95 weight%. If it is lower than this range, there arises a problem that the flow rate of ethylene supplied to the first reactor is increased as a new raw material. On the contrary, if it exceeds this range, methane or ethane accumulates in the first reactor and recycle fluid. It is not preferable because it is.

The fluid L recycled to the first reactor may contain methane or ethane.

[Description of Step (2B)]

In the step (2B), the fluid (A) obtained in the step (1B), at least one of methanol and dimethyl ether as raw materials, and the fluid (M) recycled from the step (5B) are supplied to the second reactor to supply a second catalyst. By contact with, a fluid (I) containing propylene, olefins having 4 or more carbon atoms, ethylene, paraffins, aromatic compounds and water is obtained.

In this step (2B), <second catalyst>, <reaction raw material>, <second reactor>, <reaction conditions>, and <consumption of raw material by reaction> are described in [Step (1) 2A) is substantially the same as described in the description.

<Fluid M recycled from step (5B)>

The "fluid M recycled from process (5B)" refers to the recycle fluid (M) obtained by process (5B), and is a fluid containing a C4 or more hydrocarbon. This fluid M is a part of the fluid K rich in hydrocarbon having 4 or more carbon atoms in the step (3B). "Partial" here is normally the range of 10-99 weight% in the flow volume of the fluid K, Preferably it is the range of 50-95 weight%. Below this range, the amount of olefin recycled to the reactor decreases, resulting in a decrease in the yield of propylene. Conversely, above this range, paraffin contained in the fluid K accumulates and the fluid (I) (M) is not preferable because of the problem that the flow rate of (M) increases, resulting in an increase in facility cost and service cost.

The fluid M recycled to the second reactor is not particularly limited as long as it contains olefin, and may contain paraffin or an aromatic compound.

<Fluid (I) containing propylene, olefins having 4 or more carbon atoms, ethylene, paraffins, aromatic compounds and water>

"Fluid (I) containing propylene, C4 or more olefins, ethylene, paraffin, aromatic compound and water" means the fluid at the outlet of the 2nd reactor in a process (2B).

As the second reactor outlet fluid (I), a mixed gas containing propylene as a reaction product, unreacted raw materials, by-products and diluents is obtained. The propylene concentration 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, at least one of methanol and dimethyl ether is included, but the reaction is preferably carried out under reaction conditions in which at least one of methanol and dimethyl ether does not remain. This facilitates separation of the reaction product and the unreacted raw material. Examples of the by-product include ethylene, olefins having 4 or more carbon atoms, paraffins, aromatic compounds, and water.

The amount of ethylene contained in the fluid (I) is preferably less than 2.0 by weight relative to the propylene contained in the fluid. More preferably, it is less than 1.5, More preferably, it is less than 1.0. Thereby, it is possible to significantly reduce the installation cost and the service cost of the whole process. The weight ratio of ethylene and propylene contained in the fluid (I) can be known by quantifying the composition of the fluid by general analytical methods such as gas chromatography.

Moreover, the weight ratio of ethylene and propylene of the fluid (I) can be changed by adjusting reaction conditions, such as reaction temperature and space velocity of a 1st reactor and / or a 2nd reactor.

[Description of Step (3B)]

In the step (3B), the fluid (I) obtained in the step (2B) is a fluid rich in hydrocarbons having 2 or less carbon atoms (J), a fluid rich in propylene, a fluid rich in hydrocarbons having 4 or more carbon atoms (K) and a fluid rich in water. To separate.

The fluid (I) obtained in the step (2B) is a fluid rich in hydrocarbons having 2 or less carbon atoms (J), a fluid rich in propylene, a fluid rich in hydrocarbons having 4 or more carbon atoms, by general separation processes such as cooling, compression, and distillation. ) And water-rich fluids. Here, each fluid is not limited to one fluid but may be a plurality of fluids. For example, the fluid J rich in hydrocarbons having 2 or less carbon atoms may be one fluid containing methane, ethylene, or ethane, or two fluids, a fluid rich in methane and a fluid rich in ethylene and ethane.

Moreover, it is preferable to perform processes, such as quenching, alkali washing, dehydration, as needed. When the oxygen compound is contained in the fluid (I), at least a part of the oxygen compound is removed by the quenching step. When acidic gas, such as carbon dioxide, is contained in a reactor outlet gas, at least a part of acidic gas is removed by alkali washing. Separation of water is possible mainly by condensation by compression and cooling. The remaining water is preferably removed with an adsorbent such as molecular sieve. The water removed by condensation and / or adsorption may be supplied to wastewater treatment processes such as activated sludge, or may be used as process water or the like. When this process is in the vicinity of the steam cracking process, it is preferable to use as a steam source of a cracker. Moreover, you may recycle to the 1st reactor of process (1B) and / or the 2nd reactor of process (2B), and may use as a dilution gas.

In addition, it is preferable that the obtained propylene-rich fluid further has high purity propylene through a purification step such as distillation. The purity of propylene is 95% or more, preferably 99% or more. More preferably, it is 99.9% or more.

The propylene produced can be used as a raw material for all propylene derivatives generally produced, for example in the production of acrylonitrile by ammoxidation, in the production of acrolein, acrylic acid and acrylic acid esters by selective oxidation, and by normal oxo reactions. It is applicable to the production of oxo alcohols such as butyl alcohol and 2-ethylhexanol, to the production of polypropylene by polymerization of propylene, and to the production of propylene oxide and propylene glycol by selective oxidation of propylene. In addition, acetone can be produced by a Wacker reaction, and methyl isobutyl ketone can be produced from acetone. Acetone can also be prepared from acetonecyanhydrin, which is finally converted to methyl methacrylate. Isopropyl alcohol can also be produced by propylene hydration. Moreover, phenol, bisphenol A, and polycarbonate resin can be manufactured from the cumene produced by alkylating benzene as a raw material.

[Description of Step (4B)]

In the step (4B), part of the fluid (L) of the fluid (J) in the step (3B) is recycled to the first reactor, and the remaining fluid is extracted from the process of the present invention.

At this time, the fluid J may be divided into the recycled fluid L and the extracted fluid without introducing the fluid J into the separation step, but the fluid J is introduced into the separation step to increase the ethylene concentration than the fluid J. May be recycled to the first reactor. The extracted fluid may be purified in order to recover active ingredients such as ethylene or may be used as a fuel. Moreover, you may use as a raw material of steam cracking.

Moreover, "outgoing from this process" means that neither of the 1st reactor and the 2nd reactor of this process is recycled.

[Description of Step (5B)]

In the step (5B), a part of the fluid (M) of the fluid (K) in the step (3B) is recycled to the second reactor, and the remaining fluid is extracted from this process.

At this time, the fluid K may be divided into the recycled fluid M and the extracted fluid without introducing the fluid K into the separation step, but the fluid K is introduced into the separation step to increase the butene concentration than the fluid K. May be recycled to the second reactor. The extracted fluid may be purified in order to recover active ingredients such as butenes and aromatic compounds, or may be used as fuel. Moreover, you may use as a raw material of steam cracking.

{Introduction of reaction raw material in 1st aspect and 2nd aspect}

In the present invention, a fluid containing an olefin having 4 or more carbon atoms may be newly supplied to the second reactor in the above-described process (2A) or (2B) as part of the raw material for propylene production.

It does not specifically limit as a C4 or more olefin used as a raw material of reaction. For example, hydrogen / CO mixture obtained by gasification of coal produced from petroleum feedstock by catalytic cracking or steam cracking (BB fraction, C4 raffinate-1, C4 raffinate-2, etc.) Obtained by conducting FT (Fischer Tropsch) synthesis using gas as a raw material, obtained by dehydrogenation or oxidative dehydrogenation of paraffins having 4 or more carbon atoms, obtained by MTO reaction, obtained by dehydration of alcohol, Olefin having 4 or more, particularly carbon 4-10, olefins obtained by various known methods, such as those obtained by hydrogenation of a diene compound having 4 or more carbon atoms, may optionally be used, and at this time, 4 carbon atoms derived from each production method. The thing of the state which the compound other than the above olefin arbitrarily mixed may be used as it is, or the refined olefin may be used.

Among these, when using an olefin raw material containing paraffins, since paraffin plays a role of a diluent gas, control of reaction temperature becomes easy, and raw material containing paraffin is often obtained at low cost, and it is preferable. More preferably, it is an olefin raw material containing normal butane and / or isobutane. Such preferable raw materials include the above-mentioned BB fraction, C4 raffinate-1 and C4 raffinate-2. Moreover, since BB fraction contains a lot of butadiene, it is preferable to use as a raw material the fluid which contacted the hydrogenation catalyst and reduced the butadiene concentration.

There is no restriction | limiting in particular in the supply amount of the fluid containing a C4 or more olefin from this process outside.

{Features of processes of steps (1A) to (5A) and processes of steps (1B) to (5B)}

As a characteristic of the process of process (1A)-(5A) which is 1st aspect, the C3 or less hydrocarbons, such as ethylene and propylene produced | generated in the 1st reactor, are not supplied to a 2nd reactor. For this reason, the propylene produced | generated in each of the 1st reactor and the 2nd reactor can be taken out efficiently as a product.

On the other hand, as a characteristic of the process of the process (1B)-(5B) which is 2nd aspect, since ethylene and propylene produced | generated in the 1st reactor are supplied to a 2nd reactor, a part of produced | generated propylene reacts and it is made into another compound. It may be converted. However, since the flow rate of the fluid (I) supplied to the separation purification system in the step (3B) is very small compared to the flow rate of the fluid (C) supplied to the separation purification system in the step (3A) of the first aspect, separation The service cost and equipment cost of the refining system are small.

As described above, since the two aspects have particular advantages, it is preferable that the process be selected in consideration of the cost of the entire process and the yield of propylene.

{Third aspect}

[Description of Step (1C)]

In the step (1C), the fluid (Q) containing olefins having 4 carbon atoms is obtained by supplying ethylene as a raw material and the fluid P recycled from the step (4C) to the first reactor and contacting with an ethylene dimerization catalyst. .

<Ethylene Dimerization Catalyst>

The "ethylene dimerization catalyst" (hereinafter sometimes referred to simply as "catalyst" in the step (1C)) used in the reaction according to the present invention is used to produce olefin (butene) having 4 carbon atoms using ethylene as a raw material. It refers to a catalyst having the ability to.

Such a catalyst is not particularly limited as long as it has a catalytic function with respect to a reaction for producing butene by dimerization of ethylene, and a conventionally known catalyst is used.

This catalyst may be a complex catalyst or a solid catalyst. For example, as a complex catalyst, a catalyst containing titanium such as a tetrabutoxytitanium-triethylaluminum composite catalyst, a catalyst containing other nickel, a catalyst containing palladium, and the like are used. As the solid catalyst, a catalyst containing nickel such as a nickel oxide supported catalyst or the like is used. It is preferable to use a complex catalyst when the reaction is carried out in the liquid phase, and a solid catalyst is preferable when the reaction is carried out in the gas phase.

These catalysts may be used individually by 1 type, and may mix and use 2 or more types.

<Reaction raw material>

It does not specifically limit as ethylene used as a raw material of reaction. For example, those produced by catalytic cracking or steam cracking from petroleum feedstocks, obtained by conducting FT (Fischer Tropsch) synthesis using hydrogen / CO mixed gas obtained by gasification of coal as a raw material, dehydrogenation of ethane By various methods known in the art, such as those obtained by the method or by the oxidative dehydrogenation method, those obtained by the metathesis reaction and homologation reaction of propylene, those obtained by the MTO reaction, and those obtained by the dehydration reaction of ethanol. What is obtained can be used arbitrarily, At this time, what is in the state in which compounds other than ethylene originating in each manufacturing method were mixed arbitrarily may be used as it is, and purified ethylene may be used.

<Fluid P Recycled from Step (4C)>

"Fluid P recycled from process (4C)" is a part of fluid recycled to a 1st reactor among the fluids T rich in C2 or less hydrocarbon obtained in process (3C), and this fluid (P) ) Contains ethylene. "Partial" here is normally the range of 10-99 weight% in the flow volume of the fluid T, Preferably it is the range of 50-95 weight%. When the ratio of the fluid P is lower than this range, there arises a problem that the flow rate of ethylene supplied to the reactor as a new raw material increases, and on the contrary, when the ratio of the fluid P exceeds this range, methane or ethane accumulates in the reactor and the recycle fluid. It is not desirable because problems arise.

As fluid P recycled to a 1st reactor, the compound which does not participate in reaction, such as methane and ethane, may be contained.

<Reactor of Ethylene Dimerization (First Reactor)>

The type of the reactor is not particularly limited, and may be a liquid phase reactor or a gas phase reactor. When the reaction is carried out in the liquid phase, a process for removing the catalyst from the reactor outlet fluid Q is formed. On the other hand, when using a solid catalyst in the gas phase, it is selected in a continuous fixed bed reactor or a fluidized bed reactor. Preferably it is a fixed bed reactor.

<Reaction conditions>

The reaction conditions vary greatly depending on the reaction type and the catalyst. Usually, when using a complex catalyst in a liquid phase, reaction temperature is 300 degrees C or less, for example, 20-200 degreeC, and reaction pressure is 0.5 MPa or more, for example, 1.0-5.0 MPa, and solid catalyst is used in a gaseous phase. When using, 200 degreeC or more, for example, 300-700 degreeC and 1 MPa or less, for example, 0.1-0.5 MPa are preferable. In the case of a liquid phase reaction, although a solvent can also be used for reaction, the produced butene may be used as a solvent. Although it will not specifically limit, if it is inert to reaction as a solvent, Paraffins are preferable. As concentration of a solvent, less than 90 weight% of the whole, for example, 0-50 weight% is preferable. Too high a concentration of the solvent is not preferable because the reaction rate is slow. In the case of gas phase reaction, diluent gas can also be used for reaction. The diluent gas is not particularly limited as long as it is inert to the reaction, and examples thereof include paraffins, aromatics, water vapor, carbon dioxide, carbon monoxide, nitrogen, argon, helium, and mixtures thereof. The concentration of the diluent gas is preferably less than 90% by volume, for example, 0 to 80% by volume. Too high a concentration of diluent gas is not preferable because the reaction rate is slowed. The concentration of the solvent or the concentration of the dilution gas can be known by general analytical methods such as gas chromatography.

<Consumption of Raw Material by Reaction>

As a consumption amount of ethylene, 50% or more is preferable with respect to the quantity of ethylene supplied to a 1st reactor. If the consumption of ethylene is too low, it is not preferable because the recycle flow rate of unreacted ethylene increases. As a means of increasing a consumption amount, the method of raising reaction temperature, reaction pressure, or the method of increasing catalyst amount are mentioned.

<Fluid (Q) containing olefins of 4 carbon atoms>

"Fluid Q containing olefin of carbon number 4" means a 1st reactor outlet fluid.

The outlet fluid Q of the first reactor usually contains unreacted ethylene, by-product hexene and the like, in addition to butene as the target product. In the case of the liquid phase reaction, a step of separating the catalyst is required, but a fluid containing ethylene, butene and hexene can be introduced into the second reactor of the step (2C) without performing any other separation. However, unreacted ethylene may be separated by a general separation method such as distillation, the separated ethylene may be recycled to the first reactor, and the remaining fluid may be introduced into the second reactor of step (2C). In addition, a part of the fluid Q, for example, 0 to 80%, is not supplied to the second reactor in the step (2C), but is outside the process of the present invention (hereinafter referred to as the "main process"). You may extract by. In this case, it is preferable to purify butene from the extracted fluid and use it for other purposes. As a specific example of another object, the raw material for butadiene manufacture by an oxidative dehydrogenation reaction or a dehydrogenation reaction is mentioned.

Moreover, "outgoing from this process" means that neither of the 1st reactor and the 2nd reactor of this process is recycled.

[Description of Step (2C)]

In step (2C), at least one of the fluid (Q) from step (1C), the fluid (R) recycled from step (5C), methanol and dimethyl ether is fed to a second reactor and contacted with a propylene production catalyst. In this way, a fluid S containing propylene, ethylene, other olefins, paraffins, aromatic compounds and water is obtained.

<Propylene production catalyst>

The term "propylene production catalyst" (hereinafter, simply referred to as "catalyst" in the step (2C)) as used herein refers to a catalyst capable of producing propylene from at least one of olefins having 4 or more carbon atoms, methanol and dimethyl ether. Say.

[catalyst]

As a catalyst used for this reaction, if it is a solid thing which has Bronsted acid point, it will not specifically limit, A conventionally well-known catalyst is used, For example, Clay minerals, such as kaolin; Impregnated and supported with acids such as sulfuric acid and phosphoric acid in a carrier such as clay mineral; Acidic ion exchange resins; Zeolites; Aluminum phosphates; And solid acid catalysts such as mesoporous silica alumina such as Al-MCM41.

Among these solid acid catalysts, those having a molecular sieve effect are preferable, and those having a low acid strength are preferred.

As the structures of the zeolites and aluminum phosphates having the molecular sieve effect among the solid acid catalysts, represented by codes prescribed by the International Zeolite Association (IZA), for example, AEI, AET, AEL, AFI, AFO, AFS, AST , ATN, BEA, CAN, CHA, EMT, ERI, EUO, FAU, FER, LEV, LTL, MAZ, MEL, MFI, MOR, MTT, MTW, MWW, OFF, PAU, RHO, STT, TON have. Among these, catalysts having a framework density of 18.0 T / nm ³ or less are preferred, and such catalysts are preferably MFI, MEL, MOR, MWW, FAU, BEA, CHA, and more preferably MFI, MEL, MOR. , MWW, CHA, and particularly preferably MFI, MEL, MWW, CHA.

Here, the framework density (unit: T / nm ³ ) means the number of T atoms (atoms other than oxygen among the atoms constituting the skeleton of the zeolite) per unit volume (1 nm ³ ) of the zeolite, This value is determined by the structure of the zeolite.

More preferably, the solid acid catalyst has micropores having a pore diameter of 0.3 to 0.9 nm, a crystalline alumino having a BET specific surface area of 200 to 700 m 2 / g and a pore volume of 0.1 to 0.5 g / ml. Silicates, metalosilicates or crystalline aluminum phosphates are preferred. In addition, the pore diameter here refers to the crystallographic free diameter of the channels defined by the International Zeolite Association (IZA), and when the shape of the pores (channels) is a round shape, it refers to the diameter. If the shape of oval indicates a short diameter.

During the addition, the aluminosilicate, preferably at least a molar ratio of _{SiO 2 / Al 2 O 3 10} . If the SiO ₂ / Al ₂ O ₃ molar ratio is too low, it is not preferable because 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, it is not preferable because the catalytic activity is lowered. The molar ratio can be obtained by conventional methods such as fluorescence X-rays and chemical analysis.

The aluminum content in the catalyst can be controlled by the amount of raw material injected during 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 other elements, such as boron and gallium, and it is preferable to substitute with boron especially.

These catalysts may be used individually by 1 type, and may mix and use 2 or more types.

In this invention, you may granulate and shape | mold using the substance and binder which are inert to reaction, or may mix and use these for reaction. Examples of the substance or binder inert to the reaction include alumina or alumina sol, silica, silica gel, quartz and mixtures thereof.

The above catalyst composition is a composition only of the catalytically active component which does not contain a substance, a binder, or the like which is inert to such a reaction. However, when the catalyst according to the present invention contains a substance, a binder, or the like which is inert to such a reaction, the above-mentioned catalytically active component and a substance, a binder or the like which are inert to such a reaction are called a catalyst and are inert to such a reaction. When it does not contain a substance, a binder, etc., it calls only a catalyst active component.

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 µm to 500 µm as an average particle diameter. If the particle size of the catalyst is too large, the surface area showing the catalytic activity is small, and if the particle size is too small, the handleability is poor, which is not preferable in either case. This average particle diameter can be calculated | required by SEM observation etc.

The preparation method of the catalyst used by this invention is not specifically limited, It can be prepared by the well-known method generally called hydrothermal synthesis. In addition, after hydrothermal synthesis, the composition may be changed by modification such as ion exchange, dealumination treatment, impregnation, or supporting.

When used for the reaction, the catalyst used in the present invention may be one having the above physical properties or composition, and may be prepared by any method.

As the catalyst, a combination of preferably using a complex catalyst containing titanium or nickel as the above-mentioned "ethylene dimerization catalyst" and using a catalyst having an MFI structure or a MWW structure as the "propylene production catalyst" are mentioned. Can be.

<Reaction raw material>

The origin of manufacture of at least one of methanol and dimethyl ether used as the reaction raw material is not particularly limited. For example, those obtained by hydrogenation of a mixed gas of coal and natural gas and hydrogen / CO derived from by-products in the steelmaking industry, those obtained by the reforming reaction of alcohols derived from plants, and those obtained by the fermentation method. And those obtained from organic materials such as recycled plastics and municipal wastes. Under the present circumstances, the thing of the state which arbitrarily mixed compounds other than methanol and dimethyl ether resulting from each manufacturing method may be used as it is, or the refined thing may be used.

<Fluid (R) Recycled from Step (5C)>

The "fluid (R) recycled from process (5C)" refers to the recycle fluid (R) obtained by process (5C), and is a fluid rich in C4 or more hydrocarbons. This fluid R is a part of fluid recycled to the 2nd reactor among the hydrocarbons rich in C4 or more hydrocarbon in the process (3C). "Partial" here is normally the range of 10-99 weight% in the flow volume of the fluid U, Preferably it is the range of 50-95 weight%. If the ratio of the fluid R is lower than this range, the flow rate of olefins of 4 or more carbon atoms supplied to the second reactor is reduced, resulting in a decrease in propylene yield. On the contrary, if the ratio (R) is higher than this range, paraffin is contained in the reactor and recycle fluid. It is not preferable because a problem of accumulation occurs.

The fluid (R) recycled to the second reactor is not particularly limited as long as it contains olefins, and may contain paraffins or aromatic compounds.

<Reactor for Propylene Production (Second Reactor)>

What is done in the second reactor is a gas phase reaction. Although there is no restriction | limiting in particular in the form of this gas phase reactor, Usually, it selects from a continuous fixed bed reactor or a fluidized bed reactor. Preferably it is a fixed bed reactor. In addition, in the case of filling the above-mentioned catalyst in the fixed bed reactor, in order to suppress the temperature distribution of the catalyst layer small, granular materials inert to the reaction of quartz sand, alumina, silica, silica-alumina and the like may be mixed with the catalyst and filled. In this case, the amount of the granular material inert to the reaction of quartz sand or the like is not particularly limited. Moreover, it is preferable that this granular material is the particle size of the grade similar to a catalyst from a uniform mixing property with a catalyst.

<Reaction conditions>

The lower limit of the reaction temperature is usually about 300 ° C. or higher, preferably 400 ° C. or higher as the gas temperature at the reactor inlet, and the upper limit of the reaction temperature is usually 700 ° C. or lower, preferably 600 ° C. or lower. When reaction temperature is too low, reaction rate is low, there exists a tendency for many unreacted raw materials to remain, and the yield of propylene also falls. On the other hand, when reaction temperature is too high, the yield of propylene will fall remarkably.

The upper limit of the reaction pressure is usually 2 MPa (absolute pressure, the same below), preferably 1 MPa or less, and more preferably 0.7 MPa or less. In addition, the minimum of reaction pressure is although it does not restrict | limit especially, Usually, it is 1 kPa or more, Preferably it is 50 kPa or more. When the reaction pressure is too high, the amount of undesirable byproducts 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 slow.

The amount of olefins having 4 or more carbon atoms to be supplied to the second reactor is 0.2 or more, preferably 0.5 or more, 10 or less, preferably 10 or less in terms of molar ratio with respect to the sum of the number of moles of methanol and two times the number of moles of dimethyl ether supplied to the reactor. Preferably less than 5.

That is, Mc4 is 0.2 to 10 times of (Mm + 2Mdm), Preferably it is 0.5 to 5 times when supply molar amount of a C4 or more olefin is Mc4, supply molar amount of methanol is Mm, and supply molar amount of dimethyl ether is Mdm. Even if this feed concentration ratio is too low or too high, reaction becomes slow and it is unpreferable. Especially, when this feed concentration ratio is too low, it is unpreferable because the consumption amount of olefin which is a raw material reduces.

Here, the supply concentration ratio can be known by quantifying the composition of each of the fluids supplied to the reactor or the mixed fluids by general analytical methods such as gas chromatography.

Moreover, when supplying at least one of a C4 or more olefin, methanol, and a dimethyl ether to a reactor, you may supply these separately, You may supply, after mixing some or all previously.

The total concentration (substrate concentration) of olefins having 4 or more carbon atoms, methanol and dimethyl ether in the total feed components supplied to the second reactor is 20% by volume or more and 80% by volume or less, preferably 30% by volume of the total. It is more than 70 volume%.

The substrate concentration can be found by quantifying the composition of each fluid to be supplied to the reactor or the mixed fluid after general analytical methods such as gas chromatography.

When the substrate concentration is too high, the production of aromatic compounds and paraffins becomes remarkable, and the selectivity of propylene tends to decrease. On the contrary, when the substrate concentration is too low, a large amount of catalyst is required because the reaction rate is slowed, and the cost of purifying the product and the construction cost of the reaction equipment are also uneconomical.

Therefore, the reaction substrate is diluted with the dilution gas described later to achieve such a substrate concentration. As a method of controlling a substrate concentration, the method of controlling the flow volume of the fluid discharged | emitted from a process is mentioned. By changing the flow rate of the fluid withdrawn from the process, it is possible to change the flow rate of the diluent gas recycled to the reactor, thereby changing the substrate concentration.

The butadiene compound may be contained in the fluid (R) recycled to the second reactor and / or in an olefin raw material fluid having 4 or more carbon atoms which is supplied from outside the process described later. As a density | concentration, 2.0 volume% or less is preferable.

Here, the butadiene concentration can be known by quantifying the composition of each fluid supplied to the second reactor or the mixed fluid by general analytical methods such as gas chromatography.

If this butadiene concentration is high, deterioration by caulking of a catalyst will accelerate. As a method of decreasing butadiene concentration, the partial hydrogenation method which contacts the fluid with a hydrogenation catalyst and converts into olefins is mentioned.

Moreover, although the aromatic compound may be contained in the fluid R recycled to a 2nd reactor, the total amount of the aromatic compound contained in all the gas supplied to a 2nd reactor contains in all the gas supplied to a 2nd reactor. It is preferable that it is less than 0.05 in molar ratio with respect to the total amount of C4 or more olefin which becomes. Here, ratio of the total amount of the said aromatic compound and the total amount of a C4 or more olefin can be understood by quantifying the composition of each fluid supplied to a 2nd reactor, or the fluid after mixing with general analytical methods, such as gas chromatography.

If the aromatic compound concentration is high, it is not preferable because at least one of the aromatic compound, methanol and dimethyl ether reacts in the reactor, and at least one of methanol and dimethyl ether is consumed more than necessary. As a method of reducing the aromatic compound concentration, a separation method by distillation is mentioned.

In the second reactor, inert to the reaction, such as paraffins, aromatics, water vapor, carbon dioxide, carbon monoxide, nitrogen, argon, helium, and mixtures thereof, in addition to ethylene, olefins having 4 or more carbon atoms and methanol and dimethyl ether Phosphorus gas may be present. Moreover, among these diluent gases, although paraffins and aromatics may react slightly depending on reaction conditions, they are defined as a dilution gas by the point that reaction amount is small.

As such a dilution gas, the impurity contained in the reaction raw material may be used as it is, or the dilution gas prepared separately may be mixed with the reaction raw material and used.

In addition, before diluting gas into a 2nd reactor, you may mix with a reaction raw material, and you may supply to a 2nd reactor separately from reaction raw material.

The space velocity is preferably between 0.1Hr 500Hr ^-1 to ^-1, and it is even more preferable between ^-1 to 1.0Hr 100Hr ^-1. If the space velocity is too high, the conversion ratio of at least one of olefin, methanol and dimethyl ether as a raw material is low, and sufficient propylene selectivity cannot be obtained. In addition, if the space velocity is too low, the amount of catalyst required to obtain a constant yield increases, the reactor becomes too large, and undesirable by-products such as aromatic compounds and paraffin are produced, and the propylene selectivity is lowered, which is not preferable. . In addition, the space velocity here is the flow volume of C4 or more olefin which is a reaction raw material with respect to the weight per weight of catalyst (catalyst active component), and the weight of a catalyst does not contain the inert component and binder used for granulation and shaping | molding of a catalyst here. Not the weight of the catalytically active component. In addition, a flow volume is a flow volume (weight / hour) of an olefin of 4 or more carbon atoms.

<Consumption of Raw Material by Reaction>

Regarding the sum of the molar flow rate of methanol supplied to the second reactor and twice the molar flow rate of dimethyl ether, the sum of the molar flow rate of methanol at the outlet of the second reactor and twice the molar flow rate of dimethyl ether is less than 1%. This is preferred. More preferably less than 0.1%. If this consumption is small and the amount of methanol and dimethyl ether at the outlet of the second reactor is excessively increased, purification of the product olefin becomes difficult. As a method of increasing a consumption amount, the method of raising reaction temperature or decreasing space velocity is mentioned.

Moreover, as for the sum total of the mole flow rates of a C4 or more olefin to supply to a 2nd reactor, the sum total of the mole flow rates of a C4 or more olefin of a 2nd reactor exit is preferably 20% or more and less than 70%. Preferably it is 25% or more and less than 60%. If the consumption is too small, the amount of unreacted olefin increases, and the flow rate of the fluid recycled to the second reactor becomes too large, which is not preferable. If the consumption is too large, undesirable compounds such as paraffin and aromatic compounds are by-produced and the propylene yield is lowered, which is not preferable. As a method of adjusting a consumption amount, the method of setting reaction temperature, a space velocity, etc. suitably is mentioned.

Here, the flow rates of methanol, dimethyl ether, and olefins having 4 or more carbon atoms to be supplied to the second reactor are determined by quantifying the composition of each fluid or mixed fluid to be supplied to the second reactor by a general analysis method such as gas chromatography. By measuring the flow rate of the fluid, the flow rate of methanol and dimethyl ether at the second reactor outlet and olefins having 4 or more carbon atoms quantifies the composition of the second reactor outlet fluid by a general method such as gas chromatography, and the second reactor outlet. This can be known by measuring or calculating the flow rate of the fluid.

<Fluid (S) containing propylene, ethylene, other olefins, paraffins, aromatic compounds and water>

"Fluid (S) containing propylene, ethylene, other olefins, paraffins, aromatic compounds and water" means the fluid at the outlet of a 2nd reactor.

As the outlet fluid S of the second reactor, a mixed gas containing propylene, unreacted raw materials, by-products and diluents as reaction products is obtained. The propylene concentration 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, at least one of methanol and dimethyl ether is included, but the reaction is preferably carried out under reaction conditions in which at least one of methanol and dimethyl ether does not remain. This facilitates separation of the reaction product and the unreacted raw material.

Examples of the by-product include ethylene, olefins having 4 or more carbon atoms, paraffins, aromatic compounds, and water. It is preferable here that the amount of ethylene contained in the reactor outlet fluid S is less than 2.0 by weight relative to the propylene contained in the fluid. More preferably, it is less than 1.5, More preferably, it is less than 1.0. If it exceeds this range, there exists a disadvantage that the installation and service facilities of the whole process become large, and construction cost increases. In addition, such equipment is undesirable because it also significantly increases service costs. On the contrary, if it can be in this range, it becomes possible to reduce significantly the installation cost and the service cost of the whole process.

[Description of Step (3C)]

In step (3C), the fluid (S) from step (2C) is a fluid rich in hydrocarbons having 2 or less carbon atoms (T), propylene rich fluids, hydrocarbons having 4 or more hydrocarbons (U), and fluids rich in water. To separate.

The fluid S obtained in the step (2C) is a fluid (T) rich in hydrocarbons having 2 or less carbon atoms, a fluid rich in propylene, a fluid rich in hydrocarbons having 4 or more carbon atoms, by general separation processes such as cooling, compression, and distillation. ) And water-rich fluids. Here, each fluid is not limited to one fluid but may be a plurality of fluids. For example, the fluid T rich in hydrocarbons having 2 or less carbon atoms may be one fluid containing methane, ethylene or ethane, or two fluids, a methane rich fluid and an ethylene and ethane rich fluid.

Moreover, it is preferable to perform processes, such as quenching, alkali washing, dehydration, as needed. When an oxygen compound is contained in the reactor outlet fluid S, at least a part of the oxygen compound is removed by the quenching step. When acidic gas, such as carbon dioxide, is contained in a reactor outlet gas, at least a part of acidic gas is removed by alkali washing. Separation of water is possible mainly by condensation by compression and cooling.

The remaining water is preferably removed with an adsorbent such as molecular sieve. The water removed by condensation and / or adsorption may be supplied to wastewater treatment processes such as activated sludge, or may be used as process water or the like. When this process is in the vicinity of the steam cracking process, it is preferable to use as a steam source of a cracker. Moreover, you may recycle to the 2nd reactor of a process (2C), and may use as a dilution gas.

In addition, it is preferable that the obtained propylene-rich fluid further has high purity propylene through a purification step such as distillation. The purity of propylene is 95% or more, preferably 99% or more. More preferably, it is 99.9% or more.

The propylene produced can be used as a raw material for all propylene derivatives generally produced, for example in the production of acrylonitrile by ammoxidation, in the production of acrolein, acrylic acid and acrylic acid esters by selective oxidation, and by normal oxo reactions. It is applicable to the production of oxo alcohols such as butyl alcohol and 2-ethylhexanol, to the production of polypropylene by polymerization of propylene, and to the production of propylene oxide and propylene glycol by selective oxidation of propylene. In addition, acetone can be produced by a Wacker reaction, and methyl isobutyl ketone can be produced from acetone. Acetone can also be prepared from acetonecyanhydrin, which is finally converted to methylmethacrylate. Isopropyl alcohol can also be produced by propylene hydration. Moreover, phenol, bisphenol A, and polycarbonate resin can be manufactured from the cumene produced by alkylating benzene as a raw material.

[Description of Step (4C)]

In step 4C, a part of the fluid P of the fluid T from the step 3C is recycled to the first reactor, and the remaining fluid is discharged from the process.

At this time, the fluid T may be divided into the recycled fluid P and the extracted fluid without introducing the fluid T into the separation step. However, the fluid T is introduced into the separation step to raise the ethylene concentration higher than the fluid T. May be recycled to the first reactor.

The fluid extracted to the outside of the process may be purified in order to recover active ingredients such as ethylene or may be used as a fuel. Moreover, you may use as a raw material of steam cracking.

In addition, as mentioned above, "partial part" is a range of 10-99 weight% normally in the flow volume of the fluid T, Preferably it is a range of 50-95 weight%. If it is lower than this range, there arises a problem that the flow rate of ethylene supplied to the first reactor is increased as a new raw material. On the contrary, if it exceeds this range, methane or ethane accumulates in the first reactor and recycle fluid. It is not preferable because it is.

[Description of Step (5C)]

In step 5C, some of the fluids R of the fluid U from the step 3C are recycled to the second reactor, and the remaining fluid is discharged from the process.

At this time, the fluid U may be divided into the recycled fluid R and the fluid discharged without introducing the fluid U into the separation step, but the fluid U is introduced into the separation step to increase the butene concentration than the fluid U. May be recycled to the second reactor. The extracted fluid may be purified in order to recover active ingredients such as butenes and aromatic compounds, or may be used as fuel. Moreover, you may use as a raw material of steam cracking.

In addition, as mentioned above, "part" is a range of 10-99 weight% normally in the flow volume of the fluid U, Preferably it is the range of 50-95 weight%. Below this range, the flow rate of olefins having 4 or more carbon atoms to be supplied to the second reactor is reduced, resulting in a decrease in propylene yield. On the contrary, if it exceeds this range, paraffin will accumulate in the second reactor and recycle fluid. Is not desirable because

Introduction of Reaction Raw Material

In the present invention, a fluid containing an olefin having 4 or more carbon atoms may be newly supplied to the second reactor in the above-described step (2C) as part of the raw material for propylene production.

It does not specifically limit as a C4 or more olefin used as a raw material of reaction. For example, those produced by catalytic cracking or steam cracking from petroleum feedstocks (BB fraction, C4 raffinate-1, C4 raffinate-2, etc.), and hydrogen / CO mixed gas obtained by gasification of coal as a raw material. Obtained by carrying out FT (Fischer Tropsch) synthesis, obtained by dehydrogenation or oxidative dehydrogenation of paraffins having 4 or more carbon atoms, obtained by MTO reaction, obtained by dehydration of alcohols, dienes having 4 or more carbon atoms Olefin with 4 or more carbon atoms, in particular with 4 to 10 carbon atoms, obtained by various known methods, such as those obtained by hydrogenation of a compound, may optionally be used. The compound in the state in which the compound was mixed arbitrarily may be used as it is, and refine | purified olefin may be used.

Among these, when using an olefin raw material containing paraffins, since paraffin plays a role of a diluent gas, control of reaction temperature becomes easy, and raw material containing paraffin is often obtained at low cost, and it is preferable. More preferably, it is an olefin raw material containing normal butane and / or isobutane. Such preferable raw materials include the above-mentioned BB fraction, C4 raffinate-1 and C4 raffinate-2. Moreover, since BB fraction contains a lot of butadiene, it is preferable to use as a raw material the fluid which contacted the hydrogenation catalyst and reduced the butadiene concentration.

There is no restriction | limiting in particular in the supply amount of the fluid containing a C4 or more olefin from this process outside.

{Embodiment of the process}

EMBODIMENT OF THE INVENTION Below, embodiment of the process of this invention is described with reference to drawings.

1 shows a first aspect of the process of the invention and FIG. 2 shows a second aspect of the process of the invention.

In FIG. 1, 10 is a 1st reactor, 20 is a 2nd reactor, 30 is a separation purification system. 101-117 represent a piping, respectively. In FIG. 2, 12 is a 1st reactor, 22 is a 2nd reactor, and 32 is a separation purification system. 201 to 217 each represent a pipe.

[Description of 1st aspect (FIG. 1)]

At least one of the ethylene raw material, methanol and dimethyl ether, and the hydrocarbon fluid F having 2 or less carbon atoms from the separation and purification system 30 are connected to the piping 101, the piping 102, the piping 103 and the piping 104, respectively. It is supplied to the 1st reactor 10 via. The fluid supplied to the reactor via the pipe 101 and / or the pipe 103 may contain paraffins having 2 or less carbon atoms, for example, methane or ethane. In addition, although the raw material fluid introduce | transduced through the piping 104 means the sum total of the fluid supplied through the piping 101, the piping 102, and the piping 103, these are necessarily before entering into the 1st reactor 10. It is not necessary to join and may be supplied to the 1st reactor 10 separately. The raw material supplied to the first reactor 10 is brought into contact with and reacted with the catalyst in the first reactor 10 to react with the reactor outlet fluid A containing propylene, olefins of 4 carbon atoms, ethylene, paraffins, aromatic compounds and water. Is obtained.

Hydrocarbon fluid G having at least one of methanol and dimethyl ether and at least 4 carbon atoms from the separation and purification system 30 is supplied to the second reactor 20 via the piping 106, the piping 107, and the piping 109, respectively. do. Moreover, you may supply a C4 or more olefin raw material to the 2nd reactor 20 through the piping 108 and the piping 109. The fluid supplied to the second reactor 20 via the pipe 108 and / or the pipe 107 may contain paraffins having 4 or more carbon atoms, such as normal butane or isobutane. Moreover, butadiene, an aromatic compound, and water may be contained in the raw material fluid supplied to the 2nd reactor 20 via the piping 109. FIG. In addition, although the raw material fluid introduced via the piping 109 means the sum total of the fluid supplied through the piping 106, the piping 107, and the piping 108 as needed, these are necessarily the 2nd reactor 20 It is not necessary to join before entering into), and may be supplied to the 2nd reactor 20 separately. The raw material supplied to the second reactor 20 is brought into contact with and reacted with the catalyst in the second reactor 20 to react with the reactor outlet gas fluid B containing propylene, olefins having 4 or more carbon atoms, ethylene, paraffins, aromatic compounds and water. ) Is obtained.

The outlet gas fluid A of the first reactor 10 and the outlet gas B of the second reactor 20 are joined via a pipe 105 and a pipe 110, respectively, to obtain a fluid C. The fluid (C) is sent to a general separation and purification system 30 such as cooling, compression, and distillation via a pipe 111, and a fluid rich in hydrocarbons having 2 or less carbon atoms (D), a fluid rich in propylene, hydrocarbons having 4 or more carbon atoms. The fluid (E) rich in water and the fluid rich in water are separated through the pipe 112, the pipe 113, the pipe 114, and the pipe 115, respectively. Here, each fluid represents one or more fluids. For example, in the case of the fluid (D) rich in hydrocarbons having 2 or less carbon atoms, one fluid containing methane, ethylene and ethane may be used, or two fluids, a fluid rich in methane and a fluid rich in ethylene and ethane.

A portion F of the hydrocarbon-rich fluid D having 2 or less carbon atoms is recycled to the first reactor 10 via the piping 103, and the remaining fluid is discharged from the process via the piping 116. At this time, the fluid (D) may be recycled to the first reactor (10) by separating and purifying the distillation or the like, the fluid having a higher ethylene concentration than the fluid (D). The fluid extracted through the pipe 116 may be purified in order to recover active ingredients such as ethylene, or may be used as a fuel. Moreover, you may use as a raw material of steam cracking.

It is preferable that the propylene-rich fluid obtained via the piping 113 obtain propylene with high purity by separation and purification such as distillation.

In addition, although the water obtained through the piping 115 may be supplied to wastewater treatment processes, such as activated sludge, it can also be used as process water etc. When this process is in the vicinity of the steam cracking process, it is preferable to use as a steam source of a cracker. Moreover, you may recycle to the 1st reactor 10 and / or the 2nd reactor 20, and may use as a dilution gas.

On the other hand, a part G of the fluid E rich in hydrocarbons having 4 or more carbon atoms is recycled to the second reactor 20 via the pipe 107, and the remaining fluid is discharged from the process via the pipe 117. At this time, the fluid (E) may be recycled to the second reactor (20) with a higher butene concentration than the fluid (E) by separation and purification such as distillation. The fluid extracted through the pipe 117 may be purified in order to recover active ingredients such as butenes and aromatic compounds, or may be used as fuel. Moreover, you may use as a raw material of steam cracking.

[Description of 2nd aspect (FIG. 2)]

At least one of ethylene raw material, methanol and dimethyl ether, and a hydrocarbon (L) rich in hydrocarbons having 2 or less carbon atoms from the separation and purification system 32 may be a pipe 201, a pipe 202, a pipe 203, and a pipe 204, respectively. ) Is supplied to the first reactor 12 via). The fluid supplied to the reactor via at least one of the pipe 201 and the pipe 203 may contain paraffins having 2 or less carbon atoms, for example, methane or ethane. In addition, although the raw material fluid introduce | transduced through the piping 204 means the sum total of the fluid supplied through the piping 201, the piping 202, and the piping 203, these are necessarily made before entering into the 1st reactor 12. It is not necessary to join and may be supplied to the 1st reactor 12 separately. The raw material supplied to the first reactor 12 is brought into contact with and reacted with the catalyst in the first reactor 12 to react with the reactor outlet fluid A containing propylene, olefins of 4 carbon atoms, ethylene, paraffins, aromatic compounds and water. Is obtained.

The at least one of the outlet fluid (A) of the first reactor 12, methanol and dimethyl ether, and the hydrocarbon fluid M having at least 4 carbon atoms from the separation and purification system 32 are respectively the pipe 205, the pipe 206, and the pipe. The second reactor 22 is supplied to the second reactor 22 via the 207 and the pipe 209. Moreover, you may supply a C4 or more olefin raw material to the 2nd reactor 22 through the piping 208 and the piping 209. The fluid supplied to the second reactor 22 via the pipe 208 and / or the pipe 207 may contain paraffins having 4 or more carbon atoms, such as normal butane or isobutane. Moreover, butadiene, an aromatic compound, and water may be contained in the raw material fluid supplied to the 2nd reactor 22 via the piping 209. In addition, although the raw material fluid introduced through the piping 209 means the sum total of the fluid supplied through the piping 205, the piping 206, the piping 207, and the piping 208 as needed, these are necessarily made. It is not necessary to join before entering the 2nd reactor 22, and may be supplied to the 2nd reactor 22 separately. The raw material supplied to the second reactor 22 is brought into contact with and reacted with the catalyst in the second reactor 22 to react with the reactor outlet fluid (gas) containing propylene, olefins having 4 or more carbon atoms, ethylene, paraffins, aromatic compounds and water. (I) is obtained.

The outlet gas fluid I of the second reactor 22 is sent to a general separation purification system 32 such as cooling, compression, and distillation via a pipe 210, and a fluid rich in hydrocarbons having 2 or less carbon atoms (J), It is separated into a propylene rich fluid, a C 4 or more hydrocarbon rich fluid, and a water rich fluid, and are taken out through the pipe 212, the pipe 213, the pipe 214, and the pipe 215, respectively. Here, each fluid represents one or more fluids. For example, in the case of the fluid (J) rich in hydrocarbons having 2 or less carbon atoms, one fluid containing methane, ethylene and ethane may be used, or two fluids, a fluid rich in methane and a fluid rich in ethylene and ethane.

A portion L of the hydrocarbon J-rich fluid J is recycled to the first reactor 12 via a pipe 203, and the remaining fluid is extracted from the process via a pipe 216. At this time, the fluid J may be recycled to the first reactor 12 in which the ethylene concentration is higher than the fluid J by separation and purification such as distillation. The fluid extracted through the pipe 216 may be purified to recover an active component such as ethylene or may be used as a fuel. Moreover, you may use as a raw material of steam cracking.

It is preferable that the propylene rich fluid obtained via the piping 213 obtain propylene with high purity by separation and purification such as distillation.

In addition, although the water obtained through the piping 215 may be supplied to wastewater treatment processes, such as activated sludge, it can also be used as process water. When this process is in the vicinity of the steam cracking process, it is preferable to use as a steam source of a cracker. Moreover, you may recycle to the 1st reactor 12 and / or the 2nd reactor 22, and may use as a dilution gas.

On the other hand, a part M of the hydrocarbon K-rich fluid K is recycled to the second reactor 22 via the pipe 207, and the remaining fluid is discharged from the process via the pipe 217. At this time, the fluid K having a higher butene concentration than the fluid K may be recycled to the second reactor 22 by separation and purification such as distillation. The fluid extracted through the pipe 217 may be purified in order to recover active ingredients such as butenes and aromatic compounds, or may be used as fuel. Moreover, you may use as a raw material of steam cracking.

[Description of 3rd Aspect (FIG. 3)]

EMBODIMENT OF THE INVENTION Below, embodiment of the process of this invention is described with reference to drawings.

3 shows a first aspect of the process of the invention.

In FIG. 3, 13 is a 1st reactor, 23 is a 2nd reactor, 33 is a separation purification system. 301-315 represent a piping, respectively.

Hydrocarbon fluid P rich in hydrocarbons having 2 or less carbon atoms from the ethylene raw material and the separation and purification system 33 is supplied to the first reactor 13 via the pipe 301, the pipe 302, and the pipe 303, respectively. . The fluid supplied to the reactor 13 via at least one of the pipe 301 and the pipe 302 may contain paraffins having 2 or less carbon atoms, for example, methane or ethane. In addition, although the raw material fluid introduce | transduced through the piping 303 means the sum total of the fluid supplied via the piping 301 and the piping 302, these do not necessarily need to join before entering the 1st reactor 13; Alternatively, the first reactor 13 may be supplied separately. The raw material supplied to the first reactor 13 is brought into contact with and reacted with the ethylene dimerization catalyst in the reactor 13 to obtain a reactor outlet fluid Q containing olefins having 4 carbon atoms.

In addition, although the 1st reactor 13 is shown as a liquid phase reactor in FIG. 3, the reactor of a gaseous phase may be sufficient. In the case of a liquid phase reactor, a catalyst separation operation is performed after the reactor. In addition, although all the fluid Q is supplied to the 2nd reactor 23 via the piping 304 and the piping 308 in FIG. 3, you may take out a part as needed and may use for another purpose. .

At least one of the reactor outlet fluid (Q), a hydrocarbon-rich hydrocarbon (R) having at least 4 carbon atoms from the separation and purification system 33, methanol and dimethyl ether, respectively, is a pipe 304, a pipe 306, a pipe 307, and It is supplied to the second reactor 23 via the pipe 308. Moreover, you may supply a C4 or more olefin raw material to the 2nd reactor 23 through the piping 305 and the piping 308. The fluid supplied to the second reactor 23 via at least one of the pipe 306 and the pipe 305 may contain paraffins having 4 or more carbon atoms, such as normal butane or isobutane. Moreover, butadiene, an aromatic compound, and water may be contained in the raw material fluid supplied to the 2nd reactor 23 via the piping 308. As shown in FIG. In addition, although the raw material fluid introduced via the piping 308 means the sum total of the fluid supplied through the piping 304, the piping 306, the piping 307, and the piping 305 as needed, these are necessarily made. It is not necessary to join before entering the 2nd reactor 23, and may be supplied to the 2nd reactor 23 separately. The raw material supplied to the second reactor 23 is brought into contact with and reacted with the propylene production catalyst in the second reactor 23 to react with the reactor outlet fluid (gas) containing propylene, ethylene, other olefins, paraffins, aromatic compounds and water. (S) is obtained.

The outlet gas fluid S of the second reactor 23 is sent to a general separation and purification system 33 such as cooling, compression, and distillation, and includes a hydrocarbon-rich fluid T having up to 2 carbon atoms, a propylene-rich fluid, and a carbon number. It is separated into four or more hydrocarbon-rich fluids U and water-rich fluids, and is taken out through the pipe 310, the pipe 311, the pipe 312 and the pipe 313, respectively. Here, each fluid represents one or more fluids. For example, in the case of a fluid (T) rich in hydrocarbons having 2 or less carbon atoms, one fluid containing methane, ethylene and ethane may be used, or two fluids, a fluid rich in methane and a fluid rich in ethylene and ethane.

A portion P of the hydrocarbon T-rich fluid T is recycled to the first reactor 13 via a pipe 302, and the remaining fluid is discharged from the process via a pipe 314. At this time, the fluid T having a higher ethylene concentration than the fluid T may be recycled to the first reactor 13 by separation and purification such as distillation. The fluid extracted through the pipe 314 may be purified to recover an active ingredient such as ethylene or may be used as a fuel. Moreover, you may use as a raw material of steam cracking.

The propylene-rich fluid obtained via the pipe 311 preferably obtains propylene with high purity by separation and purification such as distillation. In addition, although water obtained through the piping 313 may be supplied to wastewater treatment processes, such as activated sludge, it can also be used as process water etc. When this process is in the vicinity of the steam cracking process, it is preferable to use as a steam source of a cracker. Moreover, you may recycle to the 2nd reactor 23 and use it as a dilution gas.

On the other hand, a part (R) of the hydrocarbon (U) rich in hydrocarbon having 4 or more carbon atoms is recycled to the second reactor via the pipe 306, and the remaining fluid is discharged from the process via the pipe 315. At this time, the fluid U may be recycled to the second reactor 23 in which the butene concentration is higher than the fluid U by separation and purification such as distillation. The fluid extracted through the pipe 315 may be purified in order to recover active ingredients such as butenes and aromatic compounds, or may be used as fuel. Moreover, you may use as a raw material of steam cracking.

Although an Example is given to the following and this invention is demonstrated more concretely, this invention is not limited to a following example at all.

[Catalyst preparation]

The catalyst used by the following example and the comparative example was prepared as follows.

<Catalyst preparation>

26.6 g of tetrabromide-n-propylammonium (TPABr) and 4.8 g of sodium hydroxide were sequentially dissolved in 280 g of water, followed by 75 g of colloidal silica (SiO ₂ = 40 wt%, Al <0.1 wt%) and 35 g of water. The mixed solution was slowly added and stirred sufficiently to obtain an aqueous gel. Next, this gel was placed in a 1000 ml autoclave and subjected to hydrothermal synthesis at 170 ° C. for 72 hours while stirring at 300 rpm under magnetic pressure. The product was separated from the solid component by pressure filtration, thoroughly washed with water and then dried at 100 ° C. for 24 hours. The catalyst after drying was baked at 550 degreeC for 6 hours under air circulation, and Na type aluminosilicate was obtained.

2.0 g of this Na type aluminosilicate was suspended in 40 ml of 1 M ammonium nitrate aqueous solution, and it stirred at 80 degreeC for 2 hours. The liquid after treatment separated the solid component by suction filtration, and after fully washing with water, it was suspended in 40 ml of 1 M ammonium nitrate aqueous solution again, and it stirred at 80 degreeC for 2 hours. The liquid after treatment separated the solid component by suction filtration, and after fully washing with water, it dried at 100 degreeC for 24 hours. The catalyst after drying was baked for 4 hours at 500 degreeC under air circulation, and H type aluminosilicate was obtained.

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

[Production of propylene]

Below, the manufacture example and the comparative example of propylene which used the said catalyst are shown.

<Example 1>

The flow rate (weight / hour) of the ethylene raw material (pipe 201 of FIG. 2) in FIG. 2 is 100, and the flow rate (weight / hour) of the methanol raw material supplied from piping 202 and piping 206 is 225 (total), respectively. The fluid which newly enters the 2nd reactor 22, while producing the simulated gas (containing ethylene, methanol) of the 1st reactor 12 inlet (pipe 204) in the case of 250. A simulated gas (containing ethylene, methanol and butene) of a fluid in which the pipe 207 was combined was prepared, and two reactors were arranged in series as shown in FIG. 2 to produce propylene. Both reactors were filled with the catalyst and carried out under atmospheric pressure. The reactor outlet temperature of the first reactor was 450 ° C, and the reactor outlet temperature of the second reactor was 550 ° C. In the separation step 32 of the outlet gas of the second reactor, the flow rate of each fluid including the recycle gas was determined using an Aspen Plus simulator. The gas of the fluid (the fluid which combined the piping 206 and the piping 207) newly entering into the said 1st reactor inlet and the 2nd reactor 22 based on the flow volume of the obtained recycling gas (pipes 203 and 207). The composition was calculated, and the reaction was carried out again using the simulated gas prepared again. By repeating these operations about 10 times, the flow volume of each fluid in the process of FIG. 2 was finally calculated | required by experiment and simulation.

As a result, the ethylene flow rate (weight / hour) at the first reactor inlet (pipe 204) is 244, and the ethylene flow rate (weight / hour) at the first reactor outlet (pipe (205)) is 144, recycled to the second reactor. The olefin flow rate (weight / hour) of 4 or more carbon atoms of the fluid (pipe 207) used became 381. Ethylene conversion in the first reactor was 41%.

Further, the propylene flow rate (weight / hour) at the second reactor outlet (pipe 210: fluid (I)) was 185, the ethylene flow rate (weight / hour) was 156, and the olefin having 4 or more carbon atoms was 385. The amount of ethylene contained in the fluid (I) was 0.84 in weight ratio with respect to the amount of propylene.

<Example 2>

Second reactor when the flow rate (weight / hour) of the ethylene raw material (piping 301 in the drawing) in FIG. 3 is 100 and the flow rate (weight / hour) of the methanol raw material (piping 307 in the drawing) is 250 (23) A simulated gas (containing ethylene, methanol and butenes) at the inlet (pipe 308) was produced, and propylene was produced under the conditions of a reactor outlet temperature of 550 ° C. and atmospheric pressure using the catalyst. Separation process 33 of the outlet gas of the 2nd reactor used the Aspen plus simulator, and calculated | required the flow volume of each fluid containing recycled gas. In addition, the ethylene conversion rate in the 1st reactor which performs ethylene dimerization reaction was assumed to be 90%. Based on the flow rates of the obtained recycle gas (pipes 302 and 306), the gas composition at the second reactor inlet was calculated, and the reaction was carried out again using the simulated gas produced again. By repeating these operations about 10 times, the flow volume of each fluid in the process of FIG. 3 was finally calculated | required by experiment and simulation. As a result, the ethylene flow rate (weight / hour) at the inlet of the second reactor is 18, and the olefin flow rate (weight / hour) having at least 4 carbon atoms is 556, and at the second reactor outlet (piping 309: fluid S), The propylene flow rate (weight / hour) of 189, the ethylene flow rate (weight / hour) were 83, and the olefin of 4 or more carbon atoms became 404. The amount of ethylene contained in the fluid S was 0.44 in weight ratio with respect to the amount of propylene.

Comparative Example 1

Reactor 70 when the flow rate (weight / hour) of the ethylene raw material (piping 401 of FIG. 4) in FIG. 4 is set to 100, and the flow rate (weight / hour) of methanol raw material (piping 402 of FIG.) Is set to 250. ) A simulated gas (containing ethylene, methanol and butenes) at the inlet (pipe 404) was prepared, and propylene was produced under the conditions of a reactor outlet temperature of 550 ° C. and atmospheric pressure using the catalyst. Separation process 80 of reactor outlet gas calculated | required the flow volume of each fluid containing recycle gas using the Aspen plus simulator. Based on the flow rates of the obtained recycle gas (pipes 403 and 411), the gas composition at the reactor inlet was calculated, and the reaction was carried out again using the simulated gas produced again. By repeating these operations about 10 times, the flow volume of each fluid in the process of FIG. 4 was finally calculated | required by experiment and simulation.

As a result, the ethylene flow rate (weight / hour) at the reactor inlet is 589, and the olefin flow rate (weight / hour) having 4 or more carbon atoms is 321, and the propylene flow rate (weight / hour) at the reactor outlet (pipe 405) is 171, ethylene flow volume (weight / hour), 504 and olefins of 4 or more carbon atoms were 328. The amount of ethylene contained in the reactor outlet fluid was 2.95 in weight ratio with respect to the amount of propylene, which was a large value compared with Examples 1 and 2.

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

This application is based on the JP Patent application (Japanese Patent Application No. 2006-260809) of an application on September 26, 2006, and the Japanese patent application (Japanese Patent Application No. 2006-260810) of an application on September 26, 2006, The content here Is introduced as a reference.

The present invention provides a novel process in which propylene is produced from at least one of ethylene, methanol and dimethyl ether as a raw material, and the recycling amount of unreacted ethylene is low, and the installation cost and the service cost are low.

Claims (14)

In a method for producing propylene using ethylene as a raw material or at least one of ethylene, methanol and dimethyl ether as raw materials, The raw material is reacted in the first reactor in the presence of the first catalyst to obtain a fluid (X) containing olefins having 4 or more carbon atoms, A method for producing propylene, wherein a fluid containing propylene is obtained by reacting at least a portion of the fluid (X) with at least one of methanol and dimethyl ether in a second reactor in the presence of a second catalyst. In the method for producing propylene using ethylene, at least one of methanol and dimethyl ether as a raw material, After reacting ethylene with at least one of methanol and dimethyl ether in the first reactor in the presence of the first catalyst to obtain a fluid (A) containing propylene and an olefin having 4 or more carbon atoms, Propylene is obtained by reacting at least a portion of the C4 or more olefins contained in the fluid (A) with at least one of methanol and dimethyl ether in a second reactor in the presence of a second catalyst. . The method of claim 2, A process for producing propylene comprising the following steps (1A), (2A), (3A), (4A) and (5A). Step (1A): Propylene, carbon number 4, by supplying at least one of ethylene as a raw material, methanol and dimethyl ether as a raw material, and the fluid (F) recycled from step (4A) to the first reactor and contacting with the first catalyst. Process of obtaining the fluid (A) containing the fluid containing the above olefin, ethylene, paraffin, aromatic compound, and water Step (2A): Propylene, olefins having 4 or more carbon atoms, and ethylene by supplying at least one of methanol and dimethyl ether as raw materials and the fluid (G) recycled from step (5A) into a second reactor and contacting with a second catalyst. To obtain a fluid (B) containing water, paraffin, aromatic compounds and water Process (3A): The fluid (C) which mixed the said fluid (A) and the said fluid (B) is a fluid rich in C2 or less hydrocarbon (D), a propylene rich fluid, and a C4 or more hydrocarbon rich Process of separating into fluid (E) and fluid rich in water Step (4A): a step of recycling some of the fluid (F) of the fluid (D) to the first reactor and drawing out the remaining fluid from the process Step (5A): a step of recycling a part of the fluid (G) of the fluid (E) to the second reactor and drawing out the remaining fluid from the process. The method of claim 3, wherein A method for producing propylene, wherein the amount of ethylene contained in the fluid (C) is less than 2.0 by weight relative to propylene contained in the fluid. The method of claim 2, A process for producing propylene comprising the following steps (1B), (2B), (3B), (4B) and (5B). Step (1B): Propylene, carbon number 4 is obtained by supplying at least one of ethylene as a raw material, methanol and dimethyl ether as a raw material, and the fluid L recycled from step (4B) to a first reactor and contacting the first catalyst. Process of obtaining the fluid (A) containing the fluid containing the above olefin, ethylene, paraffin, aromatic compound, and water Step (2B): propylene, by feeding the fluid (A), at least one of methanol and dimethyl ether as raw materials, and the recycled fluid (M) from step (5B) into a second reactor and contacting with a second catalyst. Obtaining fluid (I) containing olefins having 4 or more carbon atoms, ethylene, paraffins, aromatic compounds and water Step (3B): Separating the fluid (I) into a hydrocarbon-rich fluid (J) having a carbon number of 2 or less, a propylene-rich fluid, a fluid having a hydrocarbon of 4 or more carbon atoms (K), and a fluid rich in water. fair Step (4B): a step of recycling some fluid L of the fluid J to the first reactor, and extracting the remaining fluid from the process Step (5B): a step of recycling a part of the fluid K of the fluid K to the second reactor and extracting the remaining fluid from the process. The method of claim 5, wherein The amount of ethylene contained in said fluid (I) is less than 2.0 by weight with respect to the propylene contained in the said fluid, The manufacturing method of propylene characterized by the above-mentioned. The method according to any one of claims 1 to 6, The second reactor is supplied with a fluid containing olefins having 4 or more carbon atoms from the outside of the process. The method according to any one of claims 1 to 7, And the temperature at the outlet of the first reactor is lower than the temperature at the outlet of the second reactor. The method according to any one of claims 1 to 8, The conversion rate of ethylene in the said 1st reactor computed by the following formula is 30% or more, The manufacturing method of propylene characterized by the above-mentioned. Ethylene conversion rate (%) = {(ethylene flow rate at the first reactor inlet-ethylene flow rate at the first reactor outlet) / ethylene flow rate at the first reactor inlet} × 100 A method for producing propylene using ethylene and at least one of methanol and dimethyl ether as a raw material, the method comprising reacting at least one of methanol and dimethyl ether with an olefin having 4 carbon atoms obtained by dimerization reaction of ethylene. Process for producing propylene, characterized in that. The method of claim 10, A process for producing propylene comprising the following steps (1C), (2C), (3C), (4C) and (5C). Step (1C): a step of obtaining a fluid (Q) containing an olefin having 4 carbon atoms by supplying ethylene as a raw material and the fluid P recycled from the step (4C) to the first reactor and contacting with an ethylene dimerization catalyst. Step (2C): by supplying fluid Q from step (1C), fluid R recycled from step (5C), at least one of methanol and dimethyl ether to a second reactor and contacting with a propylene production catalyst To obtain a fluid (S) containing propylene, ethylene, other olefins, paraffins, aromatic compounds and water Process (3C): The fluid (S) from the process (2C) includes a fluid (T) rich in hydrocarbons having 2 or less carbon atoms, a fluid rich in propylene, a fluid (U) rich in hydrocarbons having 4 or more carbon atoms, and water. Process to separate into abundant fluid Step (4C): a step of recycling some of the fluid P of the fluid T from the step 3C to the first reactor, and extracting the remaining fluid from the process Process (5C): The process of recycling some fluid R of the fluid U from process 3C to a 2nd reactor, and extracting the remaining fluid from the process. The method of claim 11, A part of the said fluid (Q) is extracted outside the process, without supplying to the 2nd reactor in a process (2C), The manufacturing method of propylene characterized by the above-mentioned. The method according to claim 11 or 12, The second reactor is supplied with a fluid containing olefins having 4 or more carbon atoms from the outside of the process. The method according to any one of claims 10 to 13, The amount of ethylene contained in said fluid (S) is less than 2.0 by weight with respect to the propylene contained in this fluid (S), The manufacturing method of propylene characterized by the above-mentioned.

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