METHOD OF PRODUCING PROPYLENE OXIDE

[Field of the Invention]

[0001]

The present invention relates to a method of producing propylene oxide. More particularly, the present invention relates to a method of producing propylene oxide, wherein the supply of propylene, which is a raw material, can be advantageously carried out.

[Background of the Invention]

[0002]

A method of producing propylene oxide wherein propylene oxide is produced by reacting an organic hydroperoxide and propylene is publicly known. For example, Patent Document 1 describes a method of deriving propylene oxide and cumyl alcohol from cumene hydroperoxide and propylene.

[0003]

Incidentally, as a method of producing propylene on an industrial scale, a method of deriving ethylene and propylene by the pyrolysis of naphtha or the like is known, which is carried out in the petrochemical industry. However, in recent years, the demand for propylene is increased compared to ethylene, and this tendency is supposed to be accelerated in the future also. As a result, there exists a problem that propylene will lack in the petrochemical industry.

[0004]

Patent Document 2 describes a method of producing styrene and propylene oxide wherein a fluidized-bed catalytic cracking unit (FCC) is established in parallel to produce ethylene and propylene to be used in a plant.

[Background Art]

[Patent Documents]

[0005]

[Patent Document 1] JP-A-2003-064069

[Patent Document 2] JP-A-2002-521351

[Summary of the Invention] [Problem to be solved by the Invention]

[0006]

However, when the ratio of ethylene/propylene economically derived through the FCC does not correspond to the ratio of ethylene/propylene demanded in the plant, the technology of Patent Document 2 is unsatisfactory in that one side of lacking ethylene or propylene has to be supplied from other sources in spite of the parallel establishment of the FCC.

In these circumstances, a problem to be solved by the present invention is to provide a method of producing propylene oxide wherein the supply of propylene, which is a raw material, can be advantageously carried out. [Means for Solving the Problem]

[0007]

That is, a first invention of the present invention relates to a method of producing propylene oxide, comprising the following steps:

a propane-dehydrogenation step (1), wherein propane is dehydrogenated to derive a section including propylene;

an epoxidation step (1), wherein propylene and an organic hydroperoxide are reacted with each other in the presence of a catalyst (1) to derive propylene oxide and an alcohol wherein at least a part of the propylene is propylene derived in the propane-dehydrogenation step

(i);

a propylene recovery step (1), wherein unreacted propylene in the epoxidation step (1) is recovered wherein the propylene is recycled to the epoxidation step (1) as at least a part of raw materials in the epoxidation step (1); and

a propylene-oxide purification step (1), wherein propylene oxide derived in the epoxidation step (1) is subjected to distillation to derive purified propylene oxide.

[0008]

Furthermore, a second invention of the present invention relates to a method of producing propylene oxide, comprising the following steps:

a propane-dehydrogenation step (2), wherein propane is dehydrogenated to derive a section including propylene;

an alkylation step (2), wherein benzene and propylene are reacted with each other in the presence of a catalyst (2) to derive cumene wherein at least a part of the propylene is the one derived in the propane-dehydrogenation step (2);

an oxidation step, wherein cumene is oxidized to derive an oxidation reaction liquid including cumene hydroperoxide;

an epoxidation step (2), wherein cumene hydroperoxide in the oxidation reaction liquid and propylene are reacted with each other in the presence of a catalyst (3) to derive an epoxy reaction liquid including propylene oxide and cumyl alcohol wherein at least a part of the propylene is propylene derived in the propane-dehydrogenation step (2);

a propylene recovery step (2), wherein unreacted propylene in the epoxidation step (2) is recovered wherein the propylene is recycled to the epoxidation step (2) as at least a part of raw materials in the epoxidation step (2);

a propylene-oxide purification step (2), wherein propylene oxide derived in the epoxidation step (2) is subjected to distillation to derive purified propylene oxide; and

a hydrogenation step, wherein cumyl alcohol derived in the epoxidation step (2) in the presence of a catalyst (4) is hydrogenated to derive cumene wherein the cumene is recycled to the oxidation step as at least a part of raw materials in the oxidation step.

[0009]

Besides, a third invention of the present invention relates to a method of producing propylene oxide, comprising the following steps:

a propane-dehydrogenation step (3), wherein propane is dehydrogenated to derive a section including propylene;

an epoxidation step (3), wherein propylene and hydrogen peroxide are reacted with each other in the presence of a catalyst (5) to derive propylene oxide and water wherein at least a part of the propylene is that derived in the propane-dehydrogenation step (3);

a propylene recovery step (3), wherein unreacted propylene in the epoxidation step (3) is recovered wherein the propylene is recycled to the epoxidation step (3) as at least a part of raw materials in the epoxidation step (3); and

a propylene-oxide purification step (3), wherein propylene oxide derived in the epoxidation step (3) is subjected to distillation to derive purified propylene oxide.

[0010]

Furthermore, a fourth invention of the present invention relates to a method of producing propylene oxide, comprising the following steps:

a propane-dehydrogenation step (4), wherein propane is dehydrogenated to derive a section including propylene;

a hydrogen peroxide production step, wherein oxygen and hydrogen are reacted with each other to derive hydrogen peroxide;

an epoxidation step (4), wherein propylene and hydrogen peroxide are reacted with each other in the presence of a catalyst (6) to derive propylene oxide and water wherein at least a part of the propylene is propylene derived in the propane-dehydrogenation step (4);

a propylene recovery step (4), wherein unreacted propylene in the epoxidation step (4) is recovered wherein the propylene is recycled to the epoxidation step (4) as at least a part of raw materials in the epoxidation step (4); and

a propylene-oxide purification step (3), wherein propylene oxide derived in the epoxidation step (4) is subjected to distillation to derive purified propylene oxide.

[Advantages of the Invention]

[0011]

The present invention can provide a method of producing propylene oxide which can advantageously carry out the supply of propylene, which is a raw material,

[Brief Description of the Drawings]

[0012]

[Fig.1] Fig.1 is a drawing giving an outline of the flow chart of Example 1;

[Fig.2] Fig.2 is a drawing giving an outline of the flow chart of Example 2;

[Fig.3] Fig.3 is a drawing giving an outline of the flow chart of Example 3; and [Fig.4] Fig.4 is a drawing giving an outline of the flow chart of Example 4;

[Mode for Carrying Out the Invention]

[0013]

(1) Method of producing propylene oxide (the first invention)

A method of producing propylene oxide relating to the first invention of the present invention is the one comprising the following steps:

a propane-dehydrogenation step (1), wherein propane is dehydrogenated to derive a section including propylene;

an epoxidation step (1), wherein propylene and an organic hydroperoxide are reacted with each other in the presence of a catalyst (1) to derive propylene oxide and an alcohol wherein at least a part of the propylene is propylene derived in the propane-dehydrogenation step

(i);

a propylene recovery step (1), wherein unreacted propylene in the epoxidation step (1) is recovered wherein the propylene is recycled to the epoxidation step (1) as at least a part of raw materials in the epoxidation step (1); and a propylene-oxide purification step (1), wherein propylene oxide derived in the epoxidation step (1) is subjected to distillation to derive purified propylene oxide.

[0014]

The propane-dehydrogenation step (1) in the first invention of the present invention is the one wherein propane is dehydrogenated to derive a section including propylene.

[0015]

The reaction for dehydrogenating propane can carry out an oxidative dehydrogenation in the presence of molecular oxygen, or can carry out an oxidative

dehydrogenation in the absence of molecular oxygen. As this kind of dehydrogenation reaction, for example, reactions described in National Publication No.2008-540492 can be enumerated. Propane used for the reaction can be crude propane. However, commonly purified propane is often used. As the reaction pattern, for example, a homogeneous dehydrogenation reaction, a heterogeneous catalytic dehydrogenation reaction, a homogeneous oxidative dehydrogenation reaction, a heterogeneous catalytic oxidative dehydrogenation reaction, or the like can be enumerated. At least one of them can be selected to derive a mixture (which is a section including propylene) including propylene, which is a reaction product, a by-product, and unreacted propane.

[0016]

In the first invention of the present invention, it is effective that a "partition step" wherein a publicly known unit operation such as rectification, adsorption, absorption, condensation, or membrane separation is separately used or combined with other unit operation(s) is provided to purify the section including propylene to a desired degree of propylene purity, and to recycle unreacted propylene to the propane-dehydrogenation step (1). As a specific example of the partition (separation) step, a method of partitioning out the above section including propylene into propane propylene and other impurities, wherein first of all, under a temperature and pressure condition under which components having a boiling point higher than that of propylene or propane, such as water, are selectively condensed, such components are removed, and then publicly known adsorption operations such as pressure swing adsorption (PSA) are combined to carry out the partition step can be enumerated.

[0017]

As a preferred specific example for carrying out the propane-dehydrogenation step (1), the following method can be enumerated.

[0018]

As reaction conditions of the propane-dehydrogenation step (1), the ones timely optimized depending on the reaction mode or catalyst of homogeneous dehydrogenation reaction, heterogeneous catalytic dehydrogenation reaction, homogeneous oxidative

dehydrogenation reaction or heterogeneous catalytic oxidative dehydrogenation reaction to be adopted should be adopted. Generally, the propane-dehydrogenation step (1) is often carried out at 400°C or more. Additionally, in order to suppress this undesirable side reaction, steam can be added.

[0019]

Reactors also are not particularly limited. However, for example, when a homogeneous reaction mode is adopted, a mixing vessel can be enumerated, while when a heterogeneous reaction mode is adopted, a fixed bed flow reactor can be enumerated.

[0020]

In the first invention of the present invention, it is preferred that it comprises the following partition step.

a partition step (1), wherein the section including propylene, derived in the propane-dehydrogenation step (1) is subjected to a partition operation to partition out the section into a section mainly including propylene and a section mainly including propane to recycle the section mainly including propane to the propane-dehydrogenation step (1).

[0021]

In the propane-dehydrogenation step (1), hydrogen can be produced as a by- product. In such a case, in the partition step (1), the hydrogen can be partitioned out such that it is included in any one section of the section mainly including propylene and the section mainly including propane, or it can be partitioned out as a section mainly including hydrogen, except both the section mainly including propylene and the section mainly including propane.

[0022]

In the propane-dehydrogenation step (1), when hydrogen is produced as a byproduct, the hydrogen can be used as a combustion fuel. Especially, it is preferred that the hydrogen is utilized as a combustion fuel source for heating service which is necessary for preheating propane, which is a raw material in the propane-dehydrogenation step (1) or necessary for controlling the reaction temperature of the dehydrogenation reaction. As a method of utilizing it as the combustion fuel source for heating service, for example, a method of pre-heating a reaction raw-material in the propane-dehydrogenation step (1) using a combustion furnace having a burner for hydrogen burning, and a method wherein a reaction area filled with a catalyst (1) is provided within a combustion furnace to heat the reaction area can be enumerated. Additionally, as another method, a method wherein hydrogen produced in the propane- dehydrogenation step (1) and oxygen in a specified amount are mixed, followed by the combustion under a catalyst can be enumerated. (For example, National Publication No.2008- 0519792, National Publication No.2009-531368, or the like exemplifies a method wherein an oxygen gas is added to hydrogen produced in the reaction, followed by the combustion under a catalyst to directly provide the reaction gas with heat.)

[0023]

In the first invention of the present invention, it is preferred that the propane- dehydrogenation step (1) is the one wherein propane is dehydrogenated to derive a section including propylene and hydrogen, and it is further preferred that it comprises the following partition step (2).

a partition step (2), wherein the section including propylene and hydrogen, derived in the propane-dehydrogenation step (1) is subjected to a partition operation to partition out the section into a section mainly including propylene, a section mainly including propane, and a section mainly including hydrogen to recycle the section mainly including propane to the propane-dehydrogenation step (1).

[0024]

In addition, in the first invention of the present invention, when the propane- dehydrogenation step (1) is the one wherein propane is dehydrogenated to derive a section including propylene and hydrogen, it is preferred that the first invention is the one wherein at least a part of a combustion fuel source for heating service, which is necessary in the step (1), uses a section including hydrogen derived in the propane-dehydrogenation step (1).

Furthermore, hydrocarbon partitioned as an impurity also can be used as combustion fuel.

[0025]

The epoxidation step (1) in the first invention of the present invention is the one wherein propylene and an organic hydroperoxide are reacted in the presence of a catalyst (1) to derive propylene oxide and an alcohol wherein at least a part of the propylene is propylene derived in the propane-dehydrogenation step (1).

[0026]

In light of deriving the object in high yield and high selectivity, the catalyst (1) used in the epoxidation step (1) in the first invention of the present invention is preferably a catalyst comprising a titanium-containing silicon oxide, and more preferably a so-called Ti-silica catalyst containing Ti which is chemically bonded to a silicon oxide. As the Ti-silica catalyst, for example, a catalyst wherein a Ti-compound is carried out on a silica carrier, a catalyst wherein a Ti-compound is complexed with a silicon oxide by a coprecipitation method or a sol- gel method, a Ti-containing zeolite compound, and the like can be enumerated.

[0027]

The organic hydroperoxide used in the epoxidation step (1) can be a dilute or concentrated refined or unrefined product. As the organic hydroperoxide, for example, ethylbenzene hydroperoxide, cumene hydroperoxide, diisopropylene hydroperoxide, and the like can be enumerated.

[0028]

The epoxidation reaction can be carried out by contacting propylene and an organic hydroperoxide with the catalyst (1). The reaction is carried out in a liquid phase using a solvent. The solvent has to be liquid at a reaction temperature and pressure, and substantially inactive to a reactant and a reaction product. The solvent can be the one which comprises a substance existing in a hydroperoxide solution to be used. For example, when ethylbenzene hydroperoxide or cumene hydroperoxide is a mixture comprising ethylbenzene or cumene, which is a raw material of ethylbenzene hydroperoxide or cumene hydroperoxide, the hydroperoxide can be substituted for the solvent without especially adding a solvent.

Otherwise, as a useful solvent, for example, an aromatic monocyclic compound, alkane, and the like can be enumerated. As the aromatic monocyclic compound, for example, benzene, toluene, chlorobenzene, orthodichlorobenzene, and the like can be enumerated. As alkane, for example, octane, decane, dodecane, and the like can be enumerated.

[0029]

The temperature of the epoxidation reaction is commonly in the range of 0 to 200°C, and preferably in the range of 25 to 200°C. The pressure of the epoxidation reaction can be a sufficient pressure to keep the reaction mixture in a liquid state, and commonly in the range of 100 to 10000 kPa.

[0030]

The catalyst (1) is preferably used in the form of slurry or a fixed bed. In case of a large-scale industrial operation, it is preferred to use a fixed bed. Furthermore, it can be carried out according to a batch type, a semi-continuous method, a continuous method, or the like. When a liquid including a raw material for reaction is passed through a fixed bed, a liquid mixture contains no catalyst, or does not substantially contain a catalyst.

[0031]

The molar ratio of propylene/an organic hydroperoxide supplied to the

epoxidation step (1) is preferably in the range of 2/1 to 50/1. When the ratio is too low, the reaction rate is decreased, so the efficiency is deteriorated, while when the ratio is too large, the amount of propylene to be recycled becomes too large, so a large amount of energy is needed in the recovery step. Thus, in case of the molar ratio range, superior efficiency can be provided.

[0032]

The propylene recovery step (1) in the first invention of the present invention is the one wherein unreacted propylene in the epoxidation step (1) is recovered to recycle the propylene to the epoxidation step (1) as at least a part of raw materials in the epoxidation step

(1).

[0033]

A preferred specific example for carrying out the propylene recovery step (1), the following method can be enumerated.

[0034]

When propylene is excessively used relative to an organic hydroperoxide, a reaction liquid issued from the epoxidation step (1) includes unreacted propylene. As a method of partitioning the propylene from the reaction liquid to recover the same, a method of distilling the reaction liquid can be enumerated. For distillation, conditions wherein propylene is easily evaporated from the reaction liquid are commonly used. The conditions of distillation are varied depending on the temperature or composition of the reaction liquid supplied to the distillation step. The pressure is commonly in the range of 0 to 5 MPa by gauge pressure, and preferably in the range of 0 to 3 MPa, while the temperature at overhead is commonly -50 to 150°C. Additionally, a method of using multiple distillation columns to distill the propylene in stages can be used.

[0035]

The propylene-oxide purification step (1) in the first invention of the present invention is the one wherein propylene oxide derived in the epoxidation step (1) is subjected to distillation to derive purified propylene oxide.

[0036]

As a preferred specific example for carrying out the propylene-oxide purification step (1), the following method can be enumerated.

[0037]

Propylene oxide subjected to the purification is the one after the recovery of unreacted propylene as mentioned above from the reaction liquid in the epoxidation step.

[0038]

Commonly, first of all an alcohol produced in the epoxidation step and a solvent are removed through distillation, and crude propylene oxide is derived. [0039]

This crude propylene oxide commonly includes water, hydrocarbon, and an oxygen-containing compound as impurities, wherein as the hydrocarbon, the one having a carbon atom number of 3 to 7 can be exemplified. As the oxygen-containing compound, the one such as methanol, acetaldehyde, acetone, propionaldehyde, methyl formate, and the like can be exemplified.

[0040]

For a method of removing these impurities, publicly known partition technologies such as distillation, extraction, adsorption, crystallization, and the like can be properly combined. However, in light of effectively removing water, hydrocarbon, and an oxygen-containing compound, it is preferred that extractive distillation wherein hydrocarbon having a carbon atom number of 7 to 10 is used as an oil solution and other distillation are combined to subject crude propylene oxide to purification.

[0041]

As hydrocarbon having a carbon atom number of 7 to 10, which is an oil solution, for example, a saturated straight-chain hydrocarbon having a carbon atom number of 7 to 10, a saturated branched-chain hydrocarbon having a carbon atom number of 7 to 10, an unsaturated straight-chain hydrocarbon having a carbon atom number of 7 to 10, an unsaturated branched- chain hydrocarbon having a carbon atom number of 7 to 10 can be enumerated, while as the saturated straight-chain hydrocarbon having a carbon atom number of 7 to 10, for example, n- heptane, n-octane, n-nonane, n-decane and the like can be enumerated, as the saturated branched- chain hydrocarbon having a carbon atom number of 7 to 10, for example, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,2-dimethylhexane, 2,3-dimethylhexane and the like can be enumerated, as the unsaturated straight-chain hydrocarbon having a carbon atom number of 7 to 20, for example, 1-heptene, 1-octene, 1-nonene, 1-decene and the like can be enumerated, as the unsaturated branched-chain hydrocarbon having a carbon atom number of 7 to 10, for example, 2-methyl-2-heptene and the like can be enumerated. These oil solutions can be used by one kind alone, or can be used by mixing two or more kinds.

[0042]

The type and operating condition of an extractive distillation column and other distillation column, the amount of the oil solutions to be used and the like can be properly decided depending on the quality of a required product.

[0043]

A purified propylene oxide derived like this satisfies a desired product quality. [0044]

(2) Method of producing propylene oxide (the second invention)

A method of producing propylene oxide relating to the second invention of the present invention is the one comprising the following steps:

a propane-dehydrogenation step (2), wherein propane is dehydrogenated to derive a section including propylene;

an alkylation step, wherein benzene and propylene are reacted with each other in the presence of a catalyst (2) to derive cumene wherein at least a part of the propylene is the one derived in the propane-dehydrogenation step (2);

an oxidation step (2), wherein cumene is oxidized to derive an oxidation reaction liquid including cumene hydroperoxide;

an epoxidation step (2), wherein cumene hydroperoxide in the oxidation reaction liquid and propylene are reacted with each other in the presence of a catalyst (3) to derive an epoxy-reaction liquid including propylene oxide and cumyl alcohol wherein at least a part of the propylene is propylene derived in the propane-dehydrogenation step (2);

a propylene recovery step (2), wherein unreacted propylene in the epoxidation step (2) is recovered wherein the propylene is recycled to the epoxidation step (2) as at least a part of raw materials in the epoxidation step (2);

a propylene-oxide purification step (2), wherein propylene oxide derived in the epoxidation step (2) is subjected to distillation to derive purified propylene oxide; and

a hydrogenation step, wherein cumyl alcohol derived in the epoxidation step (2) is subjected to hydrogenation in the presence of a catalyst (4) to derive cumene, and the cumene is recycled to the oxidation step as at least a part of raw materials in the oxidation step.

[0045]

The propane-dehydrogenation step (1) in the second invention of the present invention is the one wherein propane is dehydrogenated to derive a section including propylene, which is the same as the propane-dehydrogenation step (1) described in the first invention.

[0046]

In the second invention of the present invention, it is preferred that it comprises the following partition step (3).

a partition step (3), wherein the section including propylene, derived in the propane-dehydrogenation step (2) is subjected to a partition operation to partition out the section into a section mainly including propylene and a section mainly including propane to recycle the section mainly including propane to the propane-dehydrogenation step (2). [0047]

In the propane-dehydrogenation step (2), hydrogen can be produced as a byproduct. In such a case, in the partition step (3), the hydrogen can be partitioned out such that it is included in any one section of the section mainly including propylene and the section mainly including propane, or it can be partitioned out as a section mainly including hydrogen, except both the section mainly including propylene and the section mainly including propane.

[0048]

In the propane-dehydrogenation step (2), when hydrogen is produced as a byproduct, the hydrogen can be used as a combustion fuel. Especially, it is preferred that said hydrogen is utilized as a combustion fuel source for heating service which is necessary for preheating propane, which is a raw material in the propane-dehydrogenation step (2) or necessary for controlling the reaction temperature of the dehydrogenation reaction. As a method of utilizing it as the combustion fuel source for heating service, for example, a method of heating a raw material for reaction in the propane-dehydrogenation step (2) using a combustion furnace having a burner for hydrogen burning, and a method wherein a reaction layer filled with a catalyst (3) is provided within a combustion furnace to heat the reaction layer can be enumerated. Additionally, as another method, a method wherein hydrogen produced in the propane-dehydrogenation step (2) and oxygen in a specified amount are mixed, followed by the combustion under a catalyst can be enumerated.

[0049]

In the second invention of the present invention, it is preferred that the second invention is the one wherein propane is dehydrogenated to derive a section including propylene and hydrogen, and it is further preferred that it comprises the following partition step (4).

a partition step (4), wherein the section including propylene and hydrogen, derived in the propane-dehydrogenation step (2) is subjected to a partition operation to partition out the section into a section mainly including propylene, a section mainly including propane, and a section mainly including hydrogen to recycle the section mainly including propane to the propane-dehydrogenation step (2).

[0050]

In addition, in the second invention of the present invention, when the second invention is the one wherein propane is dehydrogenated to derive a section including propylene and hydrogen, it is preferred that the propane-dehydrogenation step (2) is the one wherein for at least a part of a combustion fuel source for heating service which is necessary in the step (2), a section including hydrogen derived in the propane-dehydrogenation step (2) is used.

Furthermore, hydrocarbon partitioned as an impurity also can be used as combustion fuel.

[0051]

The alkylation step (2) in the second invention of the present invention is the one wherein benzene and propylene are reacted with each other in the presence of a catalyst (2) to derive cumene wherein at least a part of the propylene is the one derived in the propane- dehydrogenation step (2).

[0052]

As the catalyst (2), for example, an aluminum chloride catalyst, a zeolite catalyst, a phosphate catalyst, and the like can be enumerated.

[0053]

As a preferred specific example for carrying out the alkylation step, the following method can be enumerated.

[0054]

As the condition of reaction in the alkylation step, the one properly optimized depending on a catalyst to be adopted can be adopted. For example, a pressure or temperature for reaction is varied depending on a catalyst system to be adopted, and depending on a gas phase process or liquid phase process. However, commonly it is often carried out under increased pressure and at a temperature in the range of about 50 to 500°C.

[0055]

As a reactor used in the alkylation step, for example, when a homogeneous aluminum chloride catalyst is adopted, a mixing vessel can be used, while when a zeolite catalyst is used, a fixed bed flow reactor can be used.

[0056]

The oxidation step in the second invention of the present invention is the one wherein cumene is oxidized to derive an oxidation reaction liquid including cumene

hydroperoxide.

[0057]

As a preferred specific example for carrying out the oxidation step, the following method can be enumerated.

[0058]

The oxidation of cumene is commonly carried out by auto-oxidation with an oxygen-containing gas such as air or oxygen-concentrated air. This oxidation reaction can be carried out using no additive agent, or using an additive agent such as an alkali. The common temperature of reaction is in the range of 50 to 200°C, while the pressure of reaction is between atmospheric pressure and 5 MPa. In case of an oxidation method using an additive agent, as an alkali reagent, an alkali metal compound such as NaOH, KOH, an alkaline earth metal, an alkali metal carbonate such as Na ₂ C0 ₃ , NaHC0 ₃ , or ammonia or (NH ₄ ) ₂ C0 ₃ , an alkali metal ammonium carbonate, or the like is used.

[0059]

The epoxidation step (2) in the second invention of the present invention is the one wherein cumene hydroperoxide in the oxidization reaction liquid and propylene are reacted with each other in the presence of a catalyst (3) to derive an epoxy-reaction liquid including propylene oxide and cumyl alcohol, wherein at least a part of the propylene is propylene derived in the propane-dehydrogenation step (2), reaction conditions and equipment are the same as the ones in the epoxidation step (1) described in the first invention, and as the catalyst (3), the same one exemplified as the catalyst (1) can be enumerated.

[0060]

The propylene recovery step (2) in the second invention of the present invention is the one wherein unreacted propylene in the epoxidation step (2) is recovered to recycle the propylene to the epoxidation step (2) as at least a part of raw materials in the epoxidation step (2), wherein the condition and equipment of reaction are the same as the ones in the propylene recovery step (1) described in the first invention.

[0061]

The propylene-oxide purification step (2) in the second invention of the present invention is the one wherein propylene oxide derived in the epoxidation step (2) is subjected to distillation to derive purified propylene oxide, and reaction conditions and equipment of are the same as the ones in the propylene-oxide purification step (1) described in the first invention.

[0062]

The hydrogenation step in the second invention of the present invention is the one wherein cumyl alcohol derived in the oxidation step (2) is subjected to hydrogenation in the presence of the catalyst (4) to derive cumene, and the cumene is recycled to the oxidation step as at least a part of raw materials in the oxidation step, which is preferably a

dehydration/hydrogenation method which is carried out in the order of a dehydration step and a hydrogenation step, in light of effectively recycling cumene.

In case of the dehydration/hydrogenation method, it is preferred that the catalyst (4) is used in combination of two kinds of a dehydration catalyst and a hydrogenation catalyst.

[0063] The dehydration step is the one wherein cumyl alcohol derived in the epoxidation step (2) is dehydrated in the presence of a dehydration catalyst to derive -methylstyrene and water. As the dehydration catalyst, for example, an acid, a metallic oxide, or the like is enumerated. As the acid, sulfuric acid, phosphoric acid, p-toluenesulfonic acid, or the like is enumerated. As the metallic oxide, for example, activated alumina, titania, zirconia, silica alumina, zeolite, or the like is enumerated. In light of the separation of the catalyst from the reaction liquid, the catalyst life, the selectivity, and the like, activated alumina is preferred.

[0064]

The amount of the dehydration catalyst can be satisfied with such an amount as to sufficiently invert cumyl alcohol. The inversion rate of cumyl alcohol is preferably 90 % or more, and more preferably 98 % or more.

A specific fill of the dehydration catalyst can be decided by an effector in light of the permissible temperature of reaction, the dehydration activity of a catalyst to be used, a catalyst life, and the like.

[0065]

A dehydration reaction is carried out by contacting a solution including cumyl alcohol with a dehydration catalyst. However, since in the dehydration/hydrogenation method, immediately after the dehydration reaction, a hydrogenation reaction is carried out, hydrogen can be also fed back to the catalyst. The reaction temperature in the dehydration step is commonly in the range of 50 to 450°C, and preferably in the range of 150 to 300°C. The reaction pressure in the dehydration step is commonly in the range of 10 to 10000 kPa.

[0066]

The hydrogenation step is the one wherein a-methylstyrene derived in the dehydration step is hydrogenated in the presence of a hydrogenation catalyst to derive cumene, followed by the recycle of the cumene to the oxidation step as at least a part of raw materials in the oxidation step.

[0067]

As the hydrogenation catalyst, for example, the one including a metal of the tenth or eleventh group of the periodic table can be enumerated, which is preferably the one including nickel, palladium, platinum or copper, and more preferably the one including palladium or copper in light of the suppression of the hydrogenation reaction of a nucleus in an aromatic ring, and the high yield. As a catalyst including copper, for example, copper, Raney copper, copper- chromium, copper-zinc, copper-chromium-zinc, copper-silica, copper-alumina, and the like can be enumerated. As a catalyst including palladium, palladium-alumina, palladium- silica, palladium-carbon, and the like can be enumerated. These catalysts can be used by one kind alone or by mixing two or more kinds. Furthermore, when the hydrogenation catalyst has dehydration performance at the same time, the dehydration catalyst to be used in the dehydration step can be the same as the hydrogenation catalyst to be used in the hydrogenation.

[0068]

The amount of the hydrogenation catalyst can be satisfied with an amount such that a-methylstyrene is sufficiently inverted. The inversion rate of a-methylstyrene is preferably 98 % or more.

A specific fill of the hydrogenation catalyst can be decided by an effector in light of the permissible reaction temperature, the hydrogenation activity of a catalyst to be used, a catalyst life, and the like.

[0069]

The hydrogenation reaction is carried out by contacting hydrogen and a solution including a-methylstyrene with a hydrogenation catalyst. However, since in the

dehydration/hydrogenation method, immediately after the dehydration reaction, the

hydrogenation reaction is carried out, the hydrogenation reaction can be carried out after water generated in the dehydration reaction has been partitioned by oil- water partition, or it can be carried out after water has been fed to the hydrogenation catalyst together with a-methylstyrene.

[0070]

The amount of hydrogen needed for the reaction can be satisfied with the one equimolar to that of a-methylstyrene. However, raw materials commonly include other ingredients which consume hydrogen, and thus excessive hydrogen is needed. Furthermore, the higher the partial pressure of hydrogen becomes, the more quickly the reaction is proceeded, and thus the molar ratio of hydrogen/a-methylstyrene is commonly in the range of 1 to 10, and preferably in the range of 1 to 5. Surplus hydrogen remaining after the reaction can be recycled after the partition from the reaction liquid to be used.

[0071]

The reaction temperature in the hydrogenation reaction is commonly in the range of 0 to 500°C, and preferably in the range of 30 to 300°C. The reaction pressure in the hydrogenation reaction is commonly in the range of 100 to 10000 kPa.

[0072]

A dehydration/hydrogenation method can be advantageously carried out by means of a fixed bed. The dehydration reaction and the hydrogenation reaction can use separate reactors, or can use a single reactor. However, in light of cost, it is preferred to fill a single fixed bed with the dehydration catalyst and the hydrogenation catalyst without using a multistage reactor.

[0073]

As the flow of reactants, any one case of up-fiow, down-flow and trickle- flow can be used.

[0074]

In the propane-dehydrogenation step (2), when hydrogen is produced as a byproduct, in light of the fact that hydrogen produced as a by-product can be more effectively utilized, it is preferred that at least a part of hydrogen used for the hydrogenation of cumyl alcohol in the hydrogenation step is hydrogen derived in the partition step (4).

[0075]

(3) Method of producing propylene oxide (the third invention)

A method of producing propylene oxide relating to the third invention of the present invention is the one comprising the following steps:

a propane-dehydrogenation step (3), wherein propane is dehydrogenated to derive a section including propylene;

an epoxidation step (3), wherein propylene and hydrogen peroxide are reacted with each other in the presence of a catalyst (5) to derive propylene oxide and water wherein at least a part of the propylene is propylene derived in the propane-dehydrogenation step (3);

a propylene recovery step (3), wherein unreacted propylene in the epoxidation step (3) is recovered wherein the propylene is recycled to the epoxidation step (3) as at least a part of raw materials in the epoxidation step (3); and

a propylene-oxide purification step (3), wherein propylene oxide derived in the epoxidation step (3) is subjected to distillation to derive purified propylene oxide.

[0076]

The propane-dehydrogenation step (3) in the third invention of the present invention is the one wherein propane is dehydrogenated to derive a section including propylene, which is the same as the propane-dehydrogenation step (1) described in the first invention.

[0077]

In the third invention of the present invention, it is preferred that it comprises the following partition step (5).

a partition step (5), wherein the section including propylene, derived in the propane-dehydrogenation step (3) is subjected to a partition operation to partition out the section into a section mainly including propylene and a section mainly including propane to recycle the section mainly including propane to the propane-dehydrogenation step (3).

[0078]

In the propane-dehydrogenation step (3), hydrogen can be produced as a byproduct. In such a case, in the partition step (5), the hydrogen can be partitioned out such that it is included in any one section of the section mainly including propylene and the section mainly including propane, or it can be partitioned out as a section mainly including hydrogen, except both the section mainly including propylene and the section mainly including propane.

[0079]

In the propane-dehydrogenation step (3), when hydrogen is produced as a by- product, the hydrogen can be used as a combustion fuel. Especially, it is preferred that said hydrogen is utilized as a combustion fuel source for heating service which is necessary for preheating propane, which is a raw material in the propane-dehydrogenation step (3) or necessary for controlling the reaction temperature of the dehydrogenation reaction. As a method of utilizing it as the combustion fuel source for heating service, for example, a method of heating a raw material for reaction in the propane-dehydrogenation step (3) using a combustion furnace having a burner for hydrogen burning, and a method wherein a reaction layer filled with a catalyst (5) is provided within a combustion furnace to heat the reaction layer can be enumerated. Additionally, as another method, a method wherein hydrogen produced in the propane-dehydrogenation step (3) and oxygen in a specified amount are mixed, followed by the combustion under a catalyst can be enumerated.

[0080]

In the third invention of the present invention, it is preferred that

the propane-dehydrogenation step (3) is the one wherein propane is dehydrogenated to derive a section including propylene and hydrogen, and it is further preferred that it comprises the following partition step (6).

a partition step (6), wherein the section including propylene and hydrogen, derived in the propane-dehydrogenation step (3) is subjected to a partition operation to partition out the section into a section mainly including propylene, a section mainly including propane, and a section mainly including hydrogen to recycle the section mainly including propane to the propane-dehydrogenation step (3).

[0081]

In addition, in the third invention of the present invention, when the propane- dehydrogenation step (3) is the one wherein propane is dehydrogenated to derive a section including propylene and hydrogen, it is preferred that the propane-dehydrogenation step (3) is the one wherein for at least a part of a combustion fuel source for heating service which is necessary in the step (3), a section including hydrogen derived in the propane-dehydrogenation step (3) is used. Furthermore, hydrocarbon partitioned as an impurity also can be used as combustion fuel.

[0082]

The epoxidation step (3) in the third invention of the present invention is the one wherein propylene and hydrogen peroxide are reacted with each other in the presence of a catalyst (5) to derive propylene oxide and water, wherein at least a part of the propylene is propylene derived in the propane-dehydrogenation step (3), and reaction conditions and equipment are the same as the ones in the epoxidation step (1) described in the first invention, and as the catalyst (5), the same one as the one exemplified as the catalyst (1) can be

enumerated.

[0083]

As a method of producing hydrogen peroxide to be used in the epoxidation step (3), the one wherein oxygen and hydrogen are reacted with each other to produce hydrogen peroxide can be enumerated. Hydrogen peroxide is generally known as an unstable substance. Therefore, in the present invention, in light of the stability and stable supply of hydrogen peroxide, it is preferred that the production process of hydrogen peroxide as described hereinafter is established in processes to produce it. Furthermore, in the propane- dehydrogenation step, when hydrogen is produced as a by-product, in light of the effective utilization of hydrogen, it is preferred that at least a part of hydrogen to be used in the production process of hydrogen peroxide as described hereinafter is hydrogen derived in the partition step (6).

[0084]

The propylene recovery step (3) in the third invention of the present invention is the one wherein unreacted propylene in the epoxidation step (3) is recovered to recycle the propylene to the epoxidation step (3) as at least a part of raw materials in the epoxidation step (3), wherein reaction conditions and equipment are the same as the ones in the propylene recovery step (1) described in the first invention.

[0085]

The propylene-oxide purification step (3) in the third invention of the present invention is the one wherein propylene oxide derived in the epoxidation step (3) is subjected to distillation to derive purified propylene oxide, and reaction conditions and equipment of are the same as the ones in the propylene-oxide purification step (1) described in the first invention. [0086]

(4) Method of producing propylene oxide (the fourth invention)

A method of producing propylene oxide relating to the fourth invention of the present invention is the one comprising the following steps:

a propane-dehydrogenation step (4), wherein propane is dehydrogenated to derive a section including propylene;

a hydrogen-peroxide production step, wherein oxygen and hydrogen are reacted with each other to derive hydrogen peroxide;

an epoxidation step (4), wherein propylene and hydrogen peroxide are reacted with each other in the presence of a catalyst (6) to derive propylene oxide and water wherein at least a part of the propylene is propylene derived in the propane-dehydrogenation step (4);

a propylene recovery step (4), wherein unreacted propylene in the epoxidation step (4) is recovered wherein the propylene is recycled to the epoxidation step (4) as at least a part of raw materials in the epoxidation step (4); and

A propylene-oxide purification step (3), wherein propylene oxide derived in the epoxidation step (4) is subjected to distillation to derive purified propylene oxide.

[0087]

The hydrogen-peroxide production step in the fourth invention of the present invention is the one wherein oxygen and hydrogen are reacted with each other to derive hydrogen peroxide. As a method wherein oxygen and hydrogen are reacted with each other to derive hydrogen peroxide, for example, the one described in JPA-1988-156005, JPA-1997- 235108, JPA- 1998-7408, or the like can be enumerated.

[0088]

The propane-dehydrogenation step (4) in the fourth invention of the present invention is the one wherein propane is dehydrogenated to derive a section including propylene, which is the same as the propane-dehydrogenation step (1) described in the first invention.

[0089]

In the fourth invention of the present invention, it is preferred that it comprises the following partition step (7).

a partition step (7), wherein the section including propylene, derived in the propane-dehydrogenation step (4) is subjected to a partition operation to partition out the section into a section mainly including propylene and a section mainly including propane to recycle the section mainly including propane to the propane-dehydrogenation step (4).

[0090] In the propane-dehydrogenation step (4), hydrogen can be produced as a byproduct. In such a case, in the partition step (7), the hydrogen can be partitioned out such that it is included in any one section of the section mainly including propylene and the section mainly including propane, or it can be partitioned out as a section mainly including hydrogen, except both the section mainly including propylene and the section mainly including propane.

[0091]

In the propane-dehydrogenation step (4), when hydrogen is produced as a byproduct, the hydrogen can be used as a combustion fuel. Especially, it is preferred that the hydrogen is utilized as a combustion fuel source for heating service which is necessary for preheating propane, which is a raw material in the propane-dehydrogenation step (4) or necessary for controlling the reaction temperature of the dehydrogenation reaction. As a method of utilizing it as the combustion fuel source for heating service, for example, a method of heating a raw material for reaction in the propane-dehydrogenation step (4) using a combustion furnace having a burner for hydrogen burning, and a method wherein a reaction layer filled with the catalyst (6) is provided within a combustion furnace to heat the reaction layer can be enumerated. Additionally, as another method, a method wherein hydrogen produced in the propane-dehydrogenation step (4) and oxygen in a specified amount are mixed, followed by the combustion under a catalyst can be enumerated.

[0092]

In the fourth invention of the present invention, it is preferred that the propane-dehydrogenation step (4) is the one wherein propane is dehydrogenated to derive a section including propylene and hydrogen, and it is further preferred that it comprises the following partition step (8).

a partition step (8), wherein the section including propylene and hydrogen, derived in the propane-dehydrogenation step (4) is subjected to a partition operation to partition out the section into a section mainly including propylene, a section mainly including propane, and a section mainly including hydrogen to recycle the section mainly including propane to the propane-dehydrogenation step (4).

[0093]

In addition, in the fourth invention of the present invention, when the propane- dehydrogenation step (4) is the one wherein propane is dehydrogenated to derive a section including propylene and hydrogen, it is preferred that the propane-dehydrogenation step (4) is the one wherein for at least a part of a combustion fuel source for heating service which is necessary in the step (4), a section including hydrogen derived in the propane-dehydrogenation step (4) is used. Furthermore, hydrocarbon to be partitioned as an impurity also can be used as combustion fuel.

[0094]

In addition, in the fourth invention of the present invention, when the propane- dehydrogenation step (4) is the one wherein propane is dehydrogenated to derive a section including propylene and hydrogen, in light of the effective utilization of hydrogen, it is preferred that at least a part of hydrogen to be used in the reaction with oxygen in the hydrogen-peroxide production step is hydrogen derived in the partition step (8).

[0095]

The propylene recovery step (4) in the fourth invention of the present invention is the one wherein unreacted propylene in the epoxidation step (4) is recovered to recycle the propylene to the epoxidation step (4) as at least a part of raw materials in the epoxidation step (4), wherein reaction conditions and equipment are the same as the ones in the propylene recovery step (1) described in the first invention.

[0096]

The propylene-oxide purification step (4) in the fourth invention of the present invention is the one wherein propylene oxide derived in the epoxidation step (4) is subjected to distillation to derive purified propylene oxide, and reaction conditions and equipment of are the same as the ones in the propylene-oxide purification step (1) described in the first invention. [Examples]

[0097]

Now, the present invention will be explained by examples. For simplicity, only main reactions will be stoichiometrically explained. However, in practical processes, it will be carried out with necessary yield or selectivity by one skilled in the art.

[0098]

[Example 1]

A raw material including propane is supplied to a propane-dehydrogenation step (1) to derive a section (101) including propylene.

Then, the section (101) including propylene is subjected to a partition operation in a partition step ( 1 ) to partition out the section (101) into a section ( 102) mainly including propylene and a section (103) mainly including propane, followed by recycling the section (103) mainly including unreacted propane to the propane-dehydrogenation step.

A liquid (104) including an organic hydroperoxide and a section (102) mainly including propylene are fed to an epoxidation step (1), followed by the reaction at a molar ratio of excessive quantities of propylene relative to the organic hydroperoxide in the presence of a catalyst (1) to derive an epoxy-reaction liquid (105) including propylene oxide and an alcohol.

After unreacted propylene (106) has been recovered in a propylene recovery step (1), the epoxy-reaction liquid (105) is fed to a propylene oxide purification step (1) as a reaction liquid (107) after the propylene recovery.

[0099]

Unreacted propylene (106) recovered in the propylene recovery step is merged with a part of the section (102) mainly including propylene derived in the partition step (1) and again fed to the epoxidation step.

In a propylene-oxide purification step, not only an alcohol and propylene oxide which have been theoretically produced by an epoxy reaction are partitioned out, but also a solvent and a by-product existing in the solution are partitioned out, so that propylene oxide to satisfy product quality is derived.

[0100]

[Example 2]

A raw material including propane is supplied to a propane-dehydrogenation step (2) to derive a section (201) including propylene.

Then, the section (201) including propylene is subjected to a partition operation in a partition step (4) to partition out the section (201) into a section (202) mainly including propylene, a section (203) mainly including unreacted propane, and a section (208) mainly including hydrogen, followed by recycling the section (203) mainly including unreacted propane to the propane-dehydrogenation step (2). A section (208) mainly including hydrogen, oxygen is added to use the derived mixture as a combustion fuel for heating service in the propane dehydrogenation step (2). A part of the resultant section (202) mainly including propylene is fed to an alkylation step (2), followed by the reaction of one mole of propylene and one mole of benzene with each other in the presence of a catalyst (2) to synthesize one mole of cumene.

The resultant cumene (209) is emerged with recycled cumene to feed to an oxidation step, so that an oxidation-reaction liquid (204) including cumene hydroperoxide is derived by air oxidation.

The resultant oxidation-reaction liquid (204) including cumene hydroperoxide and the remainder of the above-mentioned section (202) mainly including propylene are fed to the epoxidation step (2), followed by the reaction at a molar ratio of excessive quantities of propylene relative to cumene hydroperoxide in the presence of a catalyst (3), so that the reaction with one mole of propylene produces one mole of propylene oxide and one mole of cumyl alcohol.

After unreacted propylene (206) has been recovered in a propylene recovery step

(2) , an epoxy-reaction liquid (205) including propylene oxide and cumyl alcohol is fed to a propylene-oxide purification step (2) as a reaction liquid (207) after the recovery of propylene.

[0101]

The unreacted propylene (206) recovered in the propylene recovery step (2) is merged with a part of the section (202) mainly including propylene derived in the partition step (4), and again supplied to the epoxidation step (2).

In a propylene-oxide purification step (2), not only cumyl alcohol and propylene oxide which have been theoretically produced in an equimolar amount by an epoxy reaction are partitioned out, but also cumene and a by-product existing in the solution are partitioned out, so that propylene oxide to satisfy product quality is derived.

On the other hand, a liquid (211) mainly including cumyl alcohol and cumene which have been partitioned out is fed to a hydrogenation step.

In the hydrogenation step, one mole of cumyl alcohol and one mole of hydrogen are used at a molar ratio of excessive amounts of hydrogen relative to cumyl alcohol in the presence of a catalyst (4) to produce one mole of cumene. In this case, a part of a section (208) including hydrogen derived in a partition step (4) as hydrogen is purified for use. The resultant cumene becomes recycled cumene (210) without distinguishing from cumene included in a liquid (211) to be fed to the hydrogenation step. On the other hand, an amount corresponding to cumene lost by a secondary reaction in each of the steps is compensated with cumene produced in the alkylation step.

[0102]

[Example 3]

A raw material including propane is supplied to a propane-dehydrogenation step

(3) to derive a section (301) including propylene.

Then, the section (301) including propylene is subjected to a partition operation in a partition step (6) to partition out the section (301) into a section (302) mainly including propylene, a section (303) mainly including unreacted propane, and a section (308) including hydrogen, followed by recycling the section (303) mainly including unreacted propane to the propane-dehydrogenation step (3). To a part of the resultant section (308) including hydrogen, oxygen is added to use the resultant mixture as a combustion fuel for heating service in the propane dehydrogenation step (3). The liquid (304) including hydrogen peroxide is fed to an epoxidation step (3) together with the section (303) mainly including propane, followed by a reaction at a molar ratio of an excessive amount of propylene relative to hydrogen peroxide in the presence of a catalyst (5), so that the reaction with one mole of propylene produces one mole propylene oxide and water.

After unreacted propylene (306) has been recovered in a propylene recovery step, an epoxy-reaction liquid (305) including propylene oxide and water is fed to a propylene-oxide purification step (3) as an epoxy-reaction liquid (307) after the recovery of propylene.

[0103]

The unreacted propylene (306) recovered in the propylene recovery step (3) is merged with a part of the section (302) mainly including propylene derived in the partition step (6), and again supplied to the epoxidation step (3).

In a propylene-oxide purification step (3), not only water and propylene oxide which have been theoretically produced in an equimolar amount by an epoxy reaction are partitioned out, but also a solvent and by-product existing in the solution are partitioned out, so that propylene oxide to satisfy product quality is derived.

[0104]

[Example 4]

A raw material including propane is supplied to a propane-dehydrogenation step (4) to derive a section (401) including propylene.

Then, the section (401) including propylene is subjected to a partition operation in a partition step (8) to partition out the section (401) into a section (402) mainly including propylene, a section (403) mainly including unreacted propane, and a section (408) including hydrogen, followed by recycling the section (403) mainly including unreacted propane to the propane-dehydrogenation step (4). To a part of the resultant section (408) including hydrogen, oxygen is added to use the resultant mixture as a combustion fuel for heating service in the propane dehydrogenation step (4). In a hydrogen-peroxide production step, hydrogen and oxygen are reacted with each other in the presence of a catalyst to derive a liquid (404) including hydrogen peroxide. In this instance, a part of the section (408) including hydrogen derived as hydrogen in the partition step (8) is purified for use. The liquid (404) including hydrogen peroxide is purified if necessary, and fed to an epoxidation step (4) together with the section

(402) mainly including propylene, followed by a reaction at a molar ratio of an excessive amount of propylene relative to hydrogen peroxide in the presence of a catalyst (6), so that the reaction with one mole of propylene produces one mole propylene oxide and water.

After unreacted propylene (406) has been recovered in a propylene recovery step, an epoxy-reaction liquid (405) including propylene oxide and water is fed to a propylene-oxide purification step (4) as an epoxy-reaction liquid (407) after the recovery of propylene.

[0105]

The unreacted propylene (406) recovered in the propylene recovery step (4) is merged with a part of the section (402) mainly including propylene derived in the partition step (8), and again supplied to the epoxidation step (4).

In a propylene-oxide purification step (4), not only water and propylene oxide which have been theoretically produced in an equimolar amount by an epoxy reaction are partitioned out, but also a solvent and by-product existing in the solution are partitioned out, so that propylene oxide to satisfy product quality is derived.

In this way, propylene oxide can be reasonably produced by using propane, which has been conventionally used as a fuel, as a raw material, without the exterior supply of propylene without being influenced by circumstances such that lack propylene.

Description of Reference Numerals]

[0106]

(101) section including propylene,

(102) section mainly including propylene,

(103) section mainly including unreacted propane,

(104) liquid including an organic hydroperoxide,

(105) epoxy-reaction liquid including propylene oxide and an alcohol,

(106) unreacted propylene,

(107) reaction liquid after propylene recovery,

(201) section including propylene,

(202) section mainly including propylene,

(203) section mainly including unreacted propane,

(204) oxidation-reaction liquid including a cumene hydroperoxide,

(205) epoxy-reaction liquid including propylene oxide and cumylalcohol,

(206) unreacted propylene,

(207) reaction liquid after propylene recovery,

(208) section including hydrogen,

(209) cumene derived in an alkylation step,

(210) recycled cumene,

(211) liquid mainly including cumyl alcohol and cumene, (301) section including propylene,

(302) section mainly including propylene,

(303) section mainly including unreacted propane,

(304) liquid including hydrogen peroxide,

(305) epoxy-reaction liquid including propylene oxide and water,

(306) unreacted propylene,

(307) reaction liquid after propylene recovery,

(308) section including hydrogen,

(401) section including propylene,

(402) section mainly including propylene,

(403) section mainly including unreacted propane,

(404) liquid including hydrogen peroxide,

(405) epoxy-reaction liquid including propylene oxide and water,

(406) unreacted propylene,

(407) reaction liquid after propylene recovery,

(408) section including hydrogen.