JP4459925B2 - Catalyst for producing liquefied petroleum gas, and method for producing liquefied petroleum gas using the catalyst - Google Patents

Description

  The present invention relates to a catalyst for producing liquefied petroleum gas whose main component is propane or butane by reacting at least one of methanol and dimethyl ether with hydrogen, and a method for producing liquefied petroleum gas using the catalyst. .

  The present invention also relates to a method for producing liquefied petroleum gas whose main component is propane or butane from synthesis gas via methanol and / or dimethyl ether. Furthermore, the present invention relates to a method for producing liquefied petroleum gas whose main component is propane or butane from a carbon-containing raw material such as natural gas via methanol and / or dimethyl ether.

  The liquefied petroleum gas (LPG) is obtained by compressing a petroleum-based or natural gas-based hydrocarbon that is in a gaseous state at normal temperature and pressure, or by simultaneously cooling it into a liquid state, and its main component is propane or butane. LPG that can be stored and transported in a liquid state has excellent portability, and unlike natural gas that requires a pipeline for supply, it can be supplied to any place in a filled state in a cylinder. There is. For this reason, LPG mainly composed of propane, that is, propane gas, is widely used as a fuel for home use and business use. Currently, propane gas is supplied to approximately 25 million households (more than 50% of all households) in Japan. In addition to household and commercial fuels, LPG is also used as fuel for moving bodies (mainly butane gas) such as cassette stoves and disposable lighters, industrial fuel, and automobile fuel.

  Conventionally, LPG is obtained by 1) a method of recovering from wet natural gas, 2) a method of recovering from crude oil stabilization (vapor pressure adjustment), 3) a method of separating / extracting what is produced in an oil refining process, etc. Has been produced.

  Propane gas, which is used as a fuel for LPG, particularly for home and business use, is very useful if a new production method that can be industrially implemented can be established in the future.

  The present inventors have so far carried out research on a method for synthesizing LPG whose main component is propane or butane from at least one of methanol and dimethyl ether and hydrogen according to the formula (I). The inventors refer to this method as a “semi-indirect method”.

  The reaction in the semi-indirect method includes a reaction for forming an olefin from methanol or dimethyl ether (olefination reaction) and a reaction for hydrogenating the olefin to form paraffin, that is, LPG (hydrogenation reaction).

  The present inventors have so far examined various catalysts used in the semi-indirect method (see, for example, Non-Patent Documents 1 to 3). However, the LPG selectivity of the semi-indirect catalyst developed so far is not yet satisfactory.

K. Asami et al. Catalysis Today, 106 (2005) 247-251 Kenji Asami, Qianwen Zhang, Hirashima Shunsuke, Xiaohong Li, Sachio Asaoka, Kaoru Fujimoto, Japan Petroleum Institute 47th Annual Meeting 53rd Research Presentation, May 2004, Tokyo Kenji Asami, Qianwen Zhang, Hirashima Shunsuke, Xiaohong Li, Sachio Asaoka, Kaoru Fujimoto, Synthesis of LPG from DME with VIIIB Metal Supported on ZSM-5, 13th Japan Energy Convention Conference, July 2004, Tokyo

  An object of the present invention is to provide a catalyst capable of highly selectively producing a hydrocarbon whose main component is propane or butane, that is, liquefied petroleum gas (LPG), using at least one of methanol and dimethyl ether as a raw material. And

  Another object of the present invention is to provide a method capable of efficiently producing liquefied petroleum gas (LPG).

The present invention includes the following inventions.
(1)
A liquefied petroleum gas production catalyst for producing liquefied petroleum gas mainly comprising propane or butane by reacting at least one of methanol and dimethyl ether with hydrogen,
A catalyst for producing a liquefied petroleum gas, comprising at least two types of zeolite catalysts.
(2)
The liquefied petroleum gas production catalyst contains a first zeolite catalyst and a second zeolite catalyst,
The first zeolite catalyst is a zeolite catalyst containing at least one selected from the group consisting of ZSM-5, USY, and β-zeolite, which may support Pd,
The liquefied petroleum gas according to (1), wherein the second zeolite catalyst is a zeolite catalyst containing Pd and containing at least one selected from the group consisting of ZSM-5, USY, and β-zeolite. Catalyst for production.
(3)
The first zeolite catalyst is a zeolite catalyst containing at least one selected from the group consisting of ZSM-5, ZSM-5 supporting Pd, USY, and β-zeolite. Catalyst for liquefied petroleum gas production.
(4)
The catalyst for producing a liquefied petroleum gas according to (2) or (3), wherein the second zeolite catalyst is β-zeolite supporting Pd.
(5)
The catalyst for producing a liquefied petroleum gas according to any one of (2) to (4), wherein the second zeolite catalyst further contains USY.
(6)
The catalyst for liquefied petroleum gas production according to any one of (2) to (5), comprising a first layer comprising a first zeolite catalyst and a second layer comprising a second zeolite catalyst.
(7)
In the presence of the liquefied petroleum gas production catalyst according to any one of (1) to (6), hydrogen is reacted with at least one of methanol and dimethyl ether to produce liquefied petroleum gas whose main component is propane or butane. A method for producing liquefied petroleum gas.
(8)
The method for producing a liquefied petroleum gas according to (7), wherein the reaction temperature at the time of reacting at least one of methanol and dimethyl ether with hydrogen is 380 ° C. or more and 500 ° C. or less.
(9)
The method for producing a liquefied petroleum gas according to (7) or (8), wherein a reaction pressure when hydrogen is reacted with at least one of methanol and dimethyl ether is 0.1 MPa or more and 5 MPa or less.
(10)
(I) a methanol production step of obtaining a reaction gas containing methanol and hydrogen by circulating a synthesis gas through a catalyst layer containing a methanol synthesis catalyst;
(Ii) The reaction gas obtained in the methanol production step is circulated through the catalyst layer containing the liquefied petroleum gas production catalyst according to any one of (1) to (6), and the main component is propane or butane. A method for producing a liquefied petroleum gas, comprising: a liquefied petroleum gas producing step for producing a liquefied petroleum gas.
(11)
(I) a dimethyl ether production process for obtaining a reaction gas containing dimethyl ether and hydrogen by circulating a synthesis gas through a catalyst layer containing a methanol synthesis catalyst and a methanol dehydration catalyst;
(Ii) The reaction gas obtained in the dimethyl ether production process is circulated through the catalyst layer containing the liquefied petroleum gas production catalyst according to any one of (1) to (6), and the main component is propane or butane. A method for producing a liquefied petroleum gas, comprising: a liquefied petroleum gas producing step for producing a liquefied petroleum gas.
(12)
(I) a synthesis gas production process for producing synthesis gas from a carbon-containing raw material and at least one selected from the group consisting of H ₂ O, O ₂ and CO ₂ ;
(Ii) a methanol production process for obtaining a reaction gas containing methanol and hydrogen by circulating a synthesis gas through a catalyst layer containing a methanol synthesis catalyst;
(Iii) The reaction gas obtained in the methanol production step is circulated through the catalyst layer containing the liquefied petroleum gas production catalyst according to any one of (1) to (6), and the main component is propane or butane. A method for producing a liquefied petroleum gas, comprising: a liquefied petroleum gas producing step for producing a liquefied petroleum gas.
(13)
(I) a synthesis gas production process for producing synthesis gas from a carbon-containing raw material and at least one selected from the group consisting of H ₂ O, O ₂ and CO ₂ ;
(Ii) a dimethyl ether production process in which a synthesis gas is circulated through a catalyst layer containing a methanol synthesis catalyst and a methanol dehydration catalyst to obtain a reaction gas containing dimethyl ether and hydrogen;
(Iii) The reaction gas obtained in the dimethyl ether production process is circulated through the catalyst layer containing the liquefied petroleum gas production catalyst according to any one of (1) to (6), and the main component is propane or butane. A method for producing a liquefied petroleum gas, comprising: a liquefied petroleum gas producing step for producing a liquefied petroleum gas.
Here, the synthesis gas refers to a mixed gas containing hydrogen and carbon monoxide, and is not limited to a mixed gas composed of hydrogen and carbon monoxide. The synthesis gas may be a mixed gas containing, for example, carbon dioxide, water, methane, ethane, ethylene, and the like. Syngas obtained by reforming natural gas usually contains carbon dioxide and water vapor in addition to hydrogen and carbon monoxide. Further, the synthesis gas may be a coal gas obtained by coal gasification or a water gas produced from coal coke.

  The present invention provides a catalyst capable of highly selectively producing a hydrocarbon whose main component is propane or butane, that is, liquefied petroleum gas (LPG), using at least one of methanol and dimethyl ether as a raw material.

  In addition, the present invention provides a method capable of efficiently producing liquefied petroleum gas (LPG).

1. Catalyst for producing liquefied petroleum gas The catalyst for producing liquefied petroleum gas of the present invention is characterized by containing at least two kinds of zeolite catalysts. In the semi-indirect method, an olefin synthesis catalyst for converting at least one of methanol and dimethyl ether into an olefin and a hydrogenation catalyst for adding hydrogen to the olefin are usually used. In the catalyst of the present invention, it is considered that at least one type of zeolite catalyst mainly functions as an olefin synthesis catalyst, and at least one other type of zeolite catalyst mainly functions as a hydrogenation catalyst. All of the existing catalysts for the semi-indirect method used a zeolite catalyst as an olefin synthesis catalyst and another catalyst as a hydrogenation catalyst. The present invention makes it possible to produce LPG with high selectivity in a semi-indirect method by combining two or more zeolite catalysts.

  In this specification, the two types of zeolite catalysts contained in the liquefied petroleum gas production catalyst are referred to as “first zeolite catalyst” and “second zeolite catalyst”, respectively. The first zeolite catalyst mainly functions as an olefin synthesis catalyst, and the second zeolite catalyst mainly functions as a hydrogenation catalyst.

1.1. First zeolite catalyst The first zeolite catalyst is preferably a zeolite catalyst containing at least one selected from the group consisting of ZSM-5, USY, and β-zeolite, which may support Pd.

_SiO 2 / _Al 2 _{O 3} molar ratio of ZSM-5 used in the first zeolite catalyst is preferably from 200 to 450.
It is preferable _SiO 2 / _Al 2 _{O 3} molar ratio of USY used in the first zeolite catalyst is 20 to 50.
The SiO ₂ / Al ₂ O ₃ molar ratio of β-zeolite used for the first zeolite catalyst is preferably 30 to 100.

If the SiO ₂ / Al ₂ O ₃ molar ratio is not less than the above lower limit, since the Al ₂ O ₃ content is small and the acid strength is weak, catalytic activity deterioration due to coking hardly occurs, and the structure is not easily destroyed by water. . If the SiO ₂ / Al ₂ O ₃ molar ratio is less than or equal to the above upper limit, the acid strength is sufficiently strong and the activity of the catalyst is high.

  ZSM-5, USY, or β-zeolite may support Pd. The amount of Pd supported in these zeolite catalysts is preferably 0 to 0.5%. If the amount of Pd supported is within this range, C1 and C2 paraffins are hardly generated.

The amount of Pd supported (% by weight) is defined as follows.
Pd loading (% by weight) = [(Pd weight) / (Pd weight + β-zeolite weight)] × 100

  The method for introducing Pd into the zeolite catalyst is not particularly limited, and can be introduced by a method such as an ion exchange method or an impregnation method.

  Pd may not be included in the form of metal, and may be included in the form of oxide, nitrate, chloride, or the like. In that case, it is preferable to convert Pd in the zeolite catalyst into metallic palladium by, for example, hydrogen reduction treatment before the reaction, from the viewpoint that higher catalytic activity can be obtained.

Examples of the most preferable one as the first zeolite catalyst include ZSM-5, ZSM-5 supporting Pd, USY, and β-zeolite. ZSM-5 is particularly preferably one having a SiO ₂ / Al ₂ O ₃ molar ratio of 90, 400, or 1000. As USY, those having a SiO ₂ / Al ₂ O ₃ molar ratio of 30 are particularly preferred. β-zeolite having a SiO ₂ / Al ₂ O ₃ molar ratio of 37 is particularly preferred.

1.2. Second Zeolite Catalyst The second zeolite catalyst is preferably ZSM-5, USY, or β-zeolite supporting Pd.
_SiO 2 / _Al 2 _{O 3} molar ratio of ZSM-5 used in the second zeolite catalyst is preferably 20 to 200.
It is preferable _SiO 2 / _Al 2 _{O 3} molar ratio of USY used in the second zeolite catalyst is 10-100.
The SiO ₂ / Al ₂ O ₃ molar ratio of β-zeolite used for the second zeolite catalyst is preferably 30-100.

If the SiO ₂ / Al ₂ O ₃ molar ratio is not less than the above lower limit, since the Al ₂ O ₃ content is small and the acid strength is weak, catalytic activity deterioration due to coking hardly occurs, and the structure is not easily destroyed by water. . If the SiO ₂ / Al ₂ O ₃ molar ratio is less than or equal to the above upper limit, the acid strength is sufficiently strong and the activity of the catalyst is high.

  The supported amount of Pd in ZSM-5, USY, or β-zeolite is preferably 0.1% to 1.0%. If the amount of Pd supported is 0.1% or more, catalytic activity deterioration due to coking hardly occurs. If the amount of Pd supported is 1.0% or less, the cost can be kept low.

  The definition of the amount of Pd supported, the method of introducing Pd, the form of Pd, etc. are the same as in the first zeolite catalyst.

As ZSM-5 used for the second zeolite catalyst, those having a SiO ₂ / Al ₂ O ₃ molar ratio of 38 are particularly preferred. As USY, those having a SiO ₂ / Al ₂ O ₃ molar ratio of 20 or 30 are particularly preferred. β-zeolite having a SiO ₂ / Al ₂ O ₃ molar ratio of 37 is particularly preferred.

The second zeolite catalyst contains, in addition to at least one selected from the group consisting of ZSM-5 supporting Pd, USY supporting Pd, and β-zeolite supporting Pd, USY not supporting Pd. It is preferable. The amount of USY added is preferably equal to or less than the other components of the second zeolite catalyst. If the added amount of USY is within this range, C1 to C2 are hardly generated. As USY, those having a SiO ₂ / Al ₂ O ₃ molar ratio of 20 or 30 are particularly preferred.

1.3. Combination of first zeolite catalyst and second zeolite catalyst (physical mixing of two kinds of catalysts)
The weight ratio of the first zeolite catalyst to the second zeolite catalyst in the liquefied petroleum gas production catalyst of the present invention can be appropriately determined according to the amount of Pd supported, but is preferably in the range of 1: 4 to 2: 1. As a typical example, ZSM-5 (SiO ₂ / Al ₂ O ₃ molar ratio is 400) is used as the first zeolite catalyst, and 0.5% Pd / β (SiO ₂ / Al ₂ O ₃ is used as the second zeolite catalyst. When the molar ratio is 37), the weight of the first zeolite catalyst: the weight of the second zeolite catalyst = 1: 2.

  Each of the first zeolite catalyst and the second zeolite catalyst can be independently selected and combined from the above preferred candidates. Most preferably, the combinations 1-8 as shown in Table 1 are mentioned.

  The catalyst for producing liquefied petroleum gas of the present invention may be in a form (mixed type) in which the first zeolite catalyst and the second zeolite catalyst are mixed, or the first layer comprising the first zeolite catalyst and the second zeolite The form (two-layer type) by which the 2nd layer which consists of catalysts was laminated | stacked may be sufficient.

  The catalyst for producing a liquefied petroleum gas of the present invention in which the first zeolite catalyst and the second zeolite catalyst are mixed is formed as necessary after uniformly mixing the first zeolite catalyst and the second zeolite catalyst. Can be manufactured. The method for mixing and molding the two catalyst components is not particularly limited, but a dry method is preferred. When both catalyst components are mixed and molded in a wet manner, the physical properties optimized for the respective functions of both catalyst components may change due to the movement of the compound between the two catalyst components. . Examples of the catalyst molding method include an extrusion molding method and a tableting molding method.

  The two-layer catalyst for producing liquefied petroleum gas of the present invention can be produced by laminating a first zeolite catalyst and a second zeolite catalyst.

  When the above two-layer catalyst is used for LPG synthesis from a raw material gas, the raw material gas flows into the catalyst from the first layer side, reaches the second layer through the first layer, and then from the second layer side. It is preferable to be distributed so as to flow out.

2. Method for producing a liquefied petroleum gas is then used liquefied petroleum gas production catalyst of the present invention, is reacted with at least one hydrogen of methanol and dimethyl ether, liquefied petroleum gas containing propane or butane as a main component, preferably predominantly A method for producing liquefied petroleum gas whose component is propane will be described.

  In the LPG production method of the present invention, methanol or dimethyl ether can be used alone as a reaction raw material, or a mixture of methanol and dimethyl ether can be used. When a mixture of methanol and dimethyl ether is used as a reaction raw material, the content ratio of methanol and dimethyl ether is not particularly limited and can be determined as appropriate.

  The reaction can be carried out in a fixed bed, a fluidized bed or a moving bed. Reaction conditions such as the raw material gas composition, reaction temperature, reaction pressure, and contact time with the catalyst can be determined as appropriate. For example, the LPG synthesis reaction can be performed under the following conditions.

  The reaction temperature is preferably 380 ° C to 500 ° C. If the reaction temperature is 380 ° C. or higher, the activity of the catalyst is sufficiently high. If reaction temperature is 500 degrees C or less, it will be hard to produce | generate C1-C2.

  The reaction pressure is preferably 0.1 MPa to 5 MPa. If the reaction pressure is 5 MPa or less, the cost can be kept low.

  The value (W / F value) obtained by dividing the amount of catalyst used (W) (unit: g) by the inlet gas flow rate (F) (unit: mol / h) when reacting hydrogen with at least one of methanol and dimethyl ether is: It is preferable that it is 0.5-10.0. If the W / F value is 0.5 or more, the conversion rate is high. If the W / F value is 10.0 or less, the amount of catalyst used may be small.

  When the reaction raw material is methanol, the concentration of methanol in the gas (also referred to as raw material gas) fed into the reactor is preferably 20 mol% or more, and preferably 30 mol% from the viewpoint of productivity and economy. The above is more preferable. Further, the concentration of methanol in the gas fed to the reactor is preferably 60 mol% or less, more preferably 40 mol% or less, from the viewpoint of suppressing the calorific value and suppressing deterioration of the catalyst.

  When the reaction raw material is methanol, the concentration of hydrogen in the gas fed to the reactor is preferably 1 mol or more with respect to 1 mol of methanol, from the viewpoint of hydrogenation rate and suppression of catalyst deterioration. Mole or more is more preferable. Further, the concentration of hydrogen in the gas fed into the reactor is preferably 3 mol or less, more preferably 2 mol or less, with respect to 1 mol of methanol from the viewpoint of productivity and economy.

  When the reaction raw material is dimethyl ether, the concentration of dimethyl ether in the gas fed into the reactor is preferably 10 mol% or more, more preferably 20 mol% or more from the viewpoint of productivity and economy. Further, the concentration of dimethyl ether in the gas fed to the reactor is preferably 40 mol% or less, more preferably 30 mol% or less, from the viewpoint of suppressing the calorific value and suppressing deterioration of the catalyst.

  When the reaction raw material is dimethyl ether, the concentration of hydrogen in the gas fed into the reactor is preferably 2 mol or more with respect to 1 mol of dimethyl ether from the viewpoint of hydrogenation rate and catalyst deterioration suppression. Mole or more is more preferable. Further, the concentration of hydrogen in the gas fed to the reactor is preferably 5 mol or less, more preferably 4 mol or less, with respect to 1 mol of dimethyl ether from the viewpoint of productivity and economy.

  When the reaction raw material is a mixture of methanol and dimethyl ether, the concentration of methanol and dimethyl ether in the gas sent to the reactor and the concentration of hydrogen in the gas sent to the reactor are the same And a range similar to the preferable range when the reaction raw material is dimethyl ether are preferable, and these preferable ranges can be calculated according to the content ratio of methanol and dimethyl ether.

  The gas fed into the reactor may contain, for example, water, an inert gas, etc. in addition to at least one of methanol and dimethyl ether as reaction raw materials and hydrogen. The gas fed into the reactor may contain carbon monoxide and / or carbon dioxide.

Note that at least one of methanol and dimethyl ether and hydrogen may be mixed and supplied to the reactor, or may be separately supplied to the reactor.
The gas fed into the reactor can be divided and fed into the reactor, thereby controlling the reaction temperature.

  The reaction can be carried out in a fixed bed, a fluidized bed, a moving bed, etc., but it is preferable to select from both aspects of controlling the reaction temperature and regenerating the catalyst. For example, as a fixed bed, a quench reactor such as an internal multi-stage quench system, a multi-tube reactor, a multi-stage reactor including a plurality of heat exchangers, a multi-stage cooling radial flow system or a double-tube heat exchange Other reactors such as a system, a built-in cooling coil system, and a mixed flow system can be used.

  The liquefied petroleum gas production catalyst can be diluted with silica, alumina, or an inert and stable heat conductor for the purpose of temperature control. In addition, the liquefied petroleum gas production catalyst can be applied to the surface of the heat exchanger for the purpose of temperature control.

  In the reaction product gas (lower paraffin-containing gas) obtained in this way, the main component of the contained hydrocarbon is propane or butane. From the viewpoint of liquefaction characteristics, the higher the total content of propane and butane in the lower paraffin-containing gas, the better. In the present invention, it is possible to obtain a lower paraffin-containing gas in which the total content of propane and butane is 60% or more, preferably 65% or more, more preferably 70% or more based on the carbon content of the hydrocarbons contained.

  Moreover, it is preferable that the lower paraffin containing gas obtained has more propane than butane from the point of combustibility and a vapor pressure characteristic.

  In addition, the obtained lower paraffin-containing gas usually contains moisture, a low-boiling component that is a substance having a boiling point or sublimation point lower than that of propane, and a high-boiling component that is a substance having a boiling point higher than that of butane. It is. Examples of the low boiling point component include hydrogen as an unreacted raw material, ethane as a by-product, methane, carbon monoxide, and carbon dioxide. Examples of the high-boiling component include high-boiling paraffins (pentane, hexane, etc.) that are by-products.

  Therefore, moisture, a low boiling point component, a high boiling point component, etc. are isolate | separated from the obtained lower paraffin containing gas as needed, and liquefied petroleum gas (LPG) which has propane or butane as a main component is obtained. If necessary, unreacted raw materials such as methanol and / or dimethyl ether are also separated by a known method.

Separation of moisture, low-boiling components, and high-boiling components can be performed by known methods.
Separation of moisture can be performed, for example, by liquid-liquid separation.

  Separation of low-boiling components can be performed, for example, by gas-liquid separation, absorption separation, distillation or the like. More specifically, it can be carried out by gas-liquid separation or absorption separation at pressurized normal temperature, gas-liquid separation or absorption separation after cooling, or a combination thereof. Moreover, it can also carry out by membrane separation or adsorption separation, and can also carry out by the combination of these, gas-liquid separation, absorption separation, and distillation. For the separation of low-boiling components, a gas recovery process commonly used in refineries (“Petroleum Refining Process”, Petroleum Society / Ed., Kodansha Scientific, 1998, p.28-p.32) is applied. be able to.

  As a method for separating the low-boiling components, an absorption process in which liquefied petroleum gas mainly composed of propane or butane is absorbed in an absorbing liquid such as high-boiling paraffin gas having a boiling point higher than butane or gasoline is preferable.

Separation of high-boiling components can be performed, for example, by gas-liquid separation, absorption separation, distillation, or the like.
The separation conditions can be appropriately determined according to a known method.
Moreover, in order to obtain liquefied petroleum gas, you may pressurize and / or cool as needed.

  For consumer use, from the viewpoint of safety at the time of use, for example, the content of low-boiling components in LPG is preferably 5 mol% or less (including 0 mol%) by separation.

  The total content of propane and butane in the LPG produced in this manner can be 90% or more, further 95% or more (including 100%) based on the amount of carbon. In addition, the content of propane in the produced LPG can be 50% or more, further 60% or more, further 65% or more (including 100%) on the basis of carbon amount. ADVANTAGE OF THE INVENTION According to this invention, LPG which has a composition suitable for the propane gas currently widely used as a fuel for household use and business can be manufactured.

3. Method for producing liquefied petroleum gas from carbon-containing raw material Methanol and dimethyl ether used as reaction raw materials in the present invention are currently industrially produced.
For example, methanol is manufactured as follows.

First, if necessary, after removing catalyst poisoning substances such as sulfur and sulfur compounds (such as desulfurization), at least selected from the group consisting of natural gas (methane) and H ₂ O, O ₂ and CO ₂ A synthesis gas is produced by reacting one kind with a reforming catalyst such as a Ni-based catalyst. As a method for producing synthesis gas, a steam reforming method, a combined reforming method or an autothermal reforming method of natural gas (methane) is well known.

The synthesis gas can also be produced by reacting a carbon-containing raw material other than natural gas with at least one selected from the group consisting of H ₂ O, O ₂ and CO ₂ by a known method. The carbon-containing raw material is any substance that contains carbon and can react with at least one selected from the group consisting of H ₂ O, O ₂ and CO ₂ to generate H ₂ and CO. For example, lower hydrocarbons such as ethane, naphtha, coal, and the like can be used.

  Next, methanol is produced from the synthesis gas by reacting carbon monoxide with hydrogen in the presence of a methanol synthesis catalyst. When using a Cu—Zn-based catalyst (a composite oxide containing Cu and Zn) such as a Cu—Zn—Al composite oxide and a Cu—Zn—Cr composite oxide as the methanol synthesis catalyst, the reaction temperature is usually 230 to 300 ° C. The reaction is carried out at a reaction pressure of about 2 to 10 MPa. When using a Zn—Cr-based catalyst (a composite oxide containing Zn and Cr) as the methanol synthesis catalyst, the reaction is usually carried out at a reaction temperature of about 250 to 400 ° C. and a reaction pressure of about 10 to 60 MPa.

  The product (unpurified methanol) thus obtained usually contains water, carbon monoxide as an unreacted raw material, carbon dioxide as a by-product, dimethyl ether, and the like. In the present invention, this unpurified methanol can also be used as a reaction raw material.

  On the other hand, dimethyl ether is produced by dehydration of methanol using a solid acid catalyst such as aluminum phosphate.

  Furthermore, a process for producing dimethyl ether directly from synthesis gas without using methanol is being put into practical use. In this process, using a slurry phase reactor, a mixed catalyst of a methanol synthesis catalyst and a methanol dehydration catalyst, for example, a methanol synthesis catalyst and a methanol dehydration catalyst, methanol synthesis catalyst: methanol dehydration catalyst = 1: 2-2: Dimethyl ether can be synthesized by reacting carbon monoxide and hydrogen at a reaction temperature of about 230 to 280 ° C. and a reaction pressure of about 3 to 7 MPa in the presence of a catalyst contained at 1 (mass ratio).

  The product (unpurified dimethyl ether) thus obtained usually contains water, carbon monoxide as an unreacted raw material, carbon dioxide as a by-product, methanol, and the like. In the present invention, this unpurified dimethyl ether can also be used as a reaction raw material.

In the present invention, a synthesis gas is produced from a carbon-containing raw material and at least one selected from the group consisting of H ₂ O, O ₂ and CO ₂ (synthesis gas production process), and a catalyst containing a methanol synthesis catalyst The synthesis gas obtained in the layer is circulated to obtain a reaction gas containing methanol and hydrogen (methanol production process). In the methanol production process, the catalyst layer containing the catalyst for liquefied petroleum gas production is obtained according to the above method. The obtained reaction gas can be circulated to produce liquefied petroleum gas whose main component is propane or butane (liquefied petroleum gas production step).

In the present invention, a synthesis gas is produced from a carbon-containing raw material and at least one selected from the group consisting of H ₂ O, O ₂ and CO ₂ (synthesis gas production process), and a methanol synthesis catalyst and methanol. A synthesis gas obtained through a catalyst layer containing a dehydration catalyst is circulated to obtain a reaction gas containing dimethyl ether and hydrogen (dimethyl ether production process), and a catalyst containing a liquefied petroleum gas production catalyst according to the above method The reaction gas obtained in the dimethyl ether production process can be passed through the layer to produce liquefied petroleum gas whose main component is propane or butane (liquefied petroleum gas production process).

  The synthesis reaction of the synthesis gas may be performed according to a known method such as the above method. Further, the synthesis reaction of methanol and the synthesis reaction of dimethyl ether may be performed according to a known method such as the above method.

In the above LPG production method, a shift reactor is provided downstream of a reformer that is a reactor for producing synthesis gas, and the composition of the synthesis gas is adjusted by a shift reaction (CO + H ₂ O → CO ₂ + H ₂ ). You can also.

  In the above LPG production method, the low-boiling components separated from the lower paraffin-containing gas in the liquefied petroleum gas production process can also be recycled as a raw material for the synthesis gas production process.

  All the low-boiling components separated from the lower paraffin-containing gas may be recycled to the synthesis gas production process, or a part may be extracted out of the system and the rest may be recycled to the synthesis gas production process. As for the low boiling point component, only a desired component can be separated and recycled to the synthesis gas production process.

  In this case, in the synthesis gas production process, the content of low-boiling components in the gas fed to the reformer, which is a reactor, that is, the content of the recycled material can be determined as appropriate.

  In order to recycle the low boiling point component, a known technique such as appropriately providing a pressure raising means in the recycle line can be employed.

  According to the present invention, by using an existing methanol synthesis plant or dimethyl ether synthesis plant and attaching the LPG production apparatus of the present invention thereto, liquefied petroleum gas can be obtained from synthesis gas or from a carbon-containing raw material such as natural gas. It is possible to manufacture.

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

Experiments (Examples 1 to 13 and Comparative Examples 1 to 5) were performed under the conditions shown in Table 2.
Terms in Table 2 will be described. β means β-zeolite. When “H” precedes ZSM-5, USY, β, it means that the zeolite is in the proton type. The symbol “Pd−” means that palladium is supported by the ion exchange method, and the symbol “Pd /” means that palladium is supported by the impregnation method. The numerical value (%) immediately before Pd means the amount of Pd supported. The numbers listed with a hyphen after ZSM-5, USY, β mean the SiO ₂ / Al ₂ O ₃ molar ratio. In Example 9, a mixture of 0.2 g of 0.5 wt% Pd-supported β-zeolite and 0.1 g of proton type USY (SiO ₂ / Al ₂ O ₃ molar ratio 30) was used as a hydrogenation catalyst. .

The ZSM-5 and β catalysts used in this experiment were prepared by the inventors. USY used was made by Catalyst Kasei Co., Ltd.
SiO ₂ used in this experiment is Q-6 (granule: 75 to 500 μm) of Fuji Silysia Chemical Ltd.

Pd was supported on zeolite by the ion exchange method by the following method. First, a solution of Pd (NO ₃ ) ₂ having a concentration corresponding to the supported amount was prepared. Then, 5 g of zeolite powder was added to 150 ml of this solution and stirred at 80 ° C. for 8 hours using a water bath. After stirring, the catalyst was recovered by filtration. The recovered catalyst was dried at 120 ° C. in an open system. Subsequently, it sintered at 500 degreeC in the air for 4 hours.

The support of Pd by the impregnation method to SiO ₂ was performed by the following method. A solution of Pd (NO ₃ ) ₂ having a concentration corresponding to the supported amount was prepared, impregnated into SiO ₂ by an equal volume method, dried at 120 ° C. overnight, and baked in air at 500 ° C. for 4 hours.

The two-layered catalyst was formed by sequentially filling the reaction tube with the catalyst components constituting each layer.
A mixed catalyst was formed by mixing catalyst components and filling the reaction tube.

  The prepared catalyst was packed in a reaction tube having an inner diameter of 6 mm. In the case of a two-layer catalyst, as shown in FIG. 1 (a), the reaction tube was packed so that the olefin synthesis catalyst layer was the upper layer and the hydrogenation catalyst layer was the lower layer. Regarding the mixed catalyst, the catalyst was packed in the arrangement shown in FIG. 1 (b). The source gas was allowed to flow from the top to the bottom in FIGS. 1 (a) and 1 (b).

After filling the catalyst, prior to the reaction, the catalyst was activated by treatment with a hydrogen stream at normal pressure at a temperature of 385 ° C. for 4 hours. After activation, the pressure in the tube was increased to a predetermined reaction pressure with H ₂ , and then dimethyl ether was introduced to start the reaction.

In each of Examples and Comparative Examples except Example 5, the reaction was performed under a plurality of temperature conditions, and the product 1 hour after the start of the reaction was analyzed by gas chromatography. In Example 5, the reaction temperature was fixed at 430 ° C., and the product was collected over time from the start of the reaction and subjected to gas chromatography analysis.
Moreover, the conversion rate (%) of diethyl ether and the conversion rate (%) to COx (X is 1 or 2) were also measured.

Diethyl ether conversion (%) = [(inlet diethyl ether flow rate (mol / h) −outlet diethyl ether flow rate (mol / h)) / inlet diethyl ether flow rate (mol / h)] × 100
Selectivity for COx (%) = COx production rate / [2 × (diethyl ether flow rate at the inlet (mol / h) −diethyl ether flow rate at the outlet (mol / h))] × 100

The analysis results of the hydrocarbons of the products of Examples 1 to 13 are shown in FIGS. The analysis results of the hydrocarbons of the products of Comparative Examples 1 to 5 are shown in FIGS. In each column shown in FIGS. 2 to 19, the arrangement order in the vertical direction of each region indicating the ratio of hydrocarbons having a predetermined number of carbon atoms corresponds to the hydrocarbons having a predetermined number of carbon atoms in the column on the right outer side of the graph. Matches the order of the legend's vertical arrangement. When the proportion of hydrocarbons having a specific number of carbon atoms is zero%, the region corresponding to the hydrocarbon is missing from the column, so the vertical arrangement order of each region in the column is the column on the right outer side of the graph. However, even in this case, the number of carbon atoms of hydrocarbons corresponding to each region can be understood by referring to the legend.
The conversion rate (%) of diethyl ether was 100% in all examples and comparative examples.

  The conversion rate (%) to COx was 0% in Examples 1 to 9, Example 13, and Comparative Examples 1 to 5. In Example 10, the conversion rate (%) to COx was 4.7% at 375 ° C. and 0.2% at 475 ° C. In Example 11, the conversion rate (%) to COx was 1.8% at 375 ° C. and 4.5% at 475 ° C. In Example 12, the conversion rate (%) to COx was 0.7% at 375 ° C. and 2.0% at 430 ° C.

It is a figure which shows the filling method of the catalyst in a reaction tube. 2 is a diagram showing the hydrocarbon composition of the product of Example 1. FIG. FIG. 3 is a diagram showing the hydrocarbon composition of the product of Example 2. FIG. 4 is a diagram showing the hydrocarbon composition of the product of Example 3. It is a figure which shows the composition of the hydrocarbon of the product of Example 4. FIG. 6 is a diagram showing the hydrocarbon composition of the product of Example 5. It is a figure which shows the composition of the hydrocarbon of the product of Example 6. FIG. 6 is a diagram showing the hydrocarbon composition of the product of Example 7. It is a figure which shows the composition of the hydrocarbon of the product of Example 8. FIG. 4 is a diagram showing the hydrocarbon composition of the product of Example 9. FIG. 4 is a diagram showing the hydrocarbon composition of the product of Example 10. FIG. 4 is a diagram showing the hydrocarbon composition of the product of Example 11. FIG. 4 is a diagram showing the hydrocarbon composition of the product of Example 12. It is a figure which shows the composition of the hydrocarbon of the product of Example 13. FIG. 3 is a diagram showing the hydrocarbon composition of the product of Comparative Example 1. It is a figure which shows the composition of the hydrocarbon of the product of the comparative example 2. It is a figure which shows the composition of the hydrocarbon of the product of the comparative example 3. It is a figure which shows the composition of the hydrocarbon of the product of the comparative example 4. It is a figure which shows the composition of the hydrocarbon of the product of the comparative example 5.

Claims (11)

A liquefied petroleum gas production catalyst for producing liquefied petroleum gas mainly comprising propane or butane by reacting at least one of methanol and dimethyl ether with hydrogen,
A first layer comprising a first zeolite catalyst containing at least one selected from the group consisting of ZSM-5, USY, and β-zeolite, which may support Pd, and ZSM-5, which supports Pd, A liquefied petroleum gas production catalyst comprising: a second layer comprising a second zeolite catalyst containing at least one selected from the group consisting of USY and β-zeolite . First zeolite catalyst of claim 1, wherein the zeolite catalyst containing at least one selected from the group consisting of ZSM-5, ZSM-5 carrying Pd, USY, and β- zeolite Catalyst for liquefied petroleum gas production. The liquefied petroleum gas production catalyst according to claim 1 or 2, wherein the second zeolite catalyst is β-zeolite supporting Pd. The catalyst for liquefied petroleum gas production according to any one of claims 1 to 3 , wherein the second zeolite catalyst further contains USY. Producing at least one of methanol and dimethyl ether and hydrogen in the presence of the liquefied petroleum gas production catalyst according to any one of claims 1 to 4 to produce liquefied petroleum gas whose main component is propane or butane. A method for producing a liquefied petroleum gas, characterized in that a raw material gas containing at least one of methanol and dimethyl ether and hydrogen is caused to flow into the first layer, to reach the second layer through the first layer, and from the second layer A method further characterized by draining. The method for producing a liquefied petroleum gas according to claim 5 , wherein the reaction temperature when hydrogen is reacted with at least one of methanol and dimethyl ether is 380 ° C or higher and 500 ° C or lower. The method for producing a liquefied petroleum gas according to claim 5 or 6 , wherein a reaction pressure when hydrogen is reacted with at least one of methanol and dimethyl ether is 0.1 MPa or more and 5 MPa or less. (1) a methanol production process for obtaining a reaction gas containing methanol and hydrogen by circulating a synthesis gas through a catalyst layer containing a methanol synthesis catalyst;
(2) The reaction gas obtained in the methanol production process is allowed to flow into the first layer of the liquefied petroleum gas production catalyst according to any one of claims 1 to 4 , and the first layer is passed through to the second layer. A method for producing a liquefied petroleum gas, comprising: a liquefied petroleum gas production step of producing a liquefied petroleum gas having a main component of propane or butane that is distributed so as to flow out from the second layer . (1) A dimethyl ether production process in which a synthesis gas is circulated through a catalyst layer containing a methanol synthesis catalyst and a methanol dehydration catalyst to obtain a reaction gas containing dimethyl ether and hydrogen;
(2) The reaction gas obtained in the dimethyl ether production process is allowed to flow into the first layer of the liquefied petroleum gas production catalyst according to any one of claims 1 to 4 , and the second layer is reached through the first layer. A method for producing a liquefied petroleum gas, comprising: a liquefied petroleum gas production step of producing a liquefied petroleum gas having a main component of propane or butane that is distributed so as to flow out from the second layer . (1) a synthesis gas production process for producing synthesis gas from a carbon-containing raw material and at least one selected from the group consisting of H ₂ O, O ₂ and CO ₂ ;
(2) a methanol production step of obtaining a reaction gas containing methanol and hydrogen by circulating a synthesis gas through a catalyst layer containing a methanol synthesis catalyst;
(3) The reaction gas obtained in the methanol production process is allowed to flow into the first layer of the liquefied petroleum gas production catalyst according to any one of claims 1 to 4 , and the second layer is reached through the first layer. A method for producing a liquefied petroleum gas, comprising: a liquefied petroleum gas production step of producing a liquefied petroleum gas having a main component of propane or butane that is distributed so as to flow out from the second layer . (1) a synthesis gas production process for producing synthesis gas from a carbon-containing raw material and at least one selected from the group consisting of H ₂ O, O ₂ and CO ₂ ;
(2) A dimethyl ether production process in which a synthesis gas is passed through a catalyst layer containing a methanol synthesis catalyst and a methanol dehydration catalyst to obtain a reaction gas containing dimethyl ether and hydrogen;
(3) The reaction gas obtained in the dimethyl ether production process is allowed to flow into the first layer of the liquefied petroleum gas production catalyst according to any one of claims 1 to 4 , and the second layer is reached through the first layer. A method for producing a liquefied petroleum gas, comprising: a liquefied petroleum gas production step of producing a liquefied petroleum gas having a main component of propane or butane that is distributed so as to flow out from the second layer .

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