JP2009195815A - Catalyst for liquefied petroleum gas production and method for manufacturing liquefied petroleum gas using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst which can cause reaction of carbon monoxide with hydrogen in a slurry bed manner to produce hydrocarbon containing propane or butane as the main component, that is liquefied petroleum gas (LPG) and moreover which is scarcely deteriorated with the lapse of time. <P>SOLUTION: The catalyst for liquefied petroleum gas production contains a Cu-Zn based methanol synthesis catalyst and a β-zeolite carrying Pd as well as one or more of Cu, Cr, Mn and Fe. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a catalyst for producing liquefied petroleum gas whose main component is propane or butane by reacting carbon monoxide with hydrogen.

  The present invention also relates to a method for producing liquefied petroleum gas whose main component is propane or butane from synthesis gas using this catalyst. 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 using this catalyst.

  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.

As a method for producing LPG, Patent Document 1 discloses a methanol synthesis catalyst such as Cu—Zn, Cr—Zn, and Pd, specifically, a CuO—ZnO—Al ₂ O ₃ catalyst and a Pd / SiO ₂ catalyst. In the presence of a mixed catalyst obtained by physically mixing a Cr—Zn-based catalyst and a zeolite having an average pore diameter of approximately 10 mm (1 nm) or more, specifically, a methanol conversion catalyst made of Y-type zeolite, hydrogen and monoxide A method of producing a liquefied petroleum gas or a hydrocarbon mixture having a composition close to this by reacting a synthesis gas composed of carbon is disclosed. However, the catalyst described in Patent Document 1 cannot always be said to have sufficient performance.

As a method for producing LPG, Non-Patent Document 1 includes 4 wt% Pd / SiO ₂ , a Cu—Zn—Al mixed oxide which is a catalyst for methanol synthesis [Cu: Zn: Al = 40: 23: 37 (atomic ratio)]. ] Or a hybrid comprising a Cu-based catalyst for low-pressure methanol synthesis (trade name: BASF S3-85) and a high-silica Y-type zeolite of SiO ₂ / Al ₂ O ₃ = 7.6 treated with water vapor at 450 ° C. for 1 hour. A method for producing a C2-C4 paraffin with a selectivity of 69-85% from synthesis gas via methanol and dimethyl ether using a catalyst is disclosed. However, it is difficult to say that the catalyst described in Non-Patent Document 1 also has sufficiently excellent performance, like the catalyst described in Patent Document 1.

  Patent Document 2 discloses a Cu—Zn-based methanol synthesis catalyst component as a catalyst capable of producing liquefied petroleum gas from carbon monoxide and hydrogen under conditions of relatively low temperature and low pressure and having little deterioration with time. Further, a catalyst for producing a liquefied petroleum gas, characterized by containing a β-zeolite catalyst component, preferably carrying 0.1 to 1% by weight of Pd, is disclosed. This catalyst has excellent catalytic performance and high stability and durability, but a process for producing LPG from synthesis gas, and a process for producing LPG from carbon-containing raw materials such as natural gas. Therefore, further improvement of the catalyst is desired. In particular, improving the stability and extending the life of the catalyst is very important in the practical application of this process.

  In addition, as a reaction format of the LPG synthesis reaction, a fixed bed reaction method has been conventionally adopted, but a slurry bed reaction method is also very promising.

  The reaction for synthesizing LPG from carbon monoxide and hydrogen is a vigorous exothermic reaction, and the removal of reaction heat is the most important technical issue. In addition, this heat generation may cause deterioration and deactivation of the catalyst. In particular, when a Cu—Zn-based methanol synthesis catalyst is used as the methanol synthesis catalyst component, the heat resistance is usually lower than that of other methanol synthesis catalysts, and therefore the catalyst tends to be deteriorated at high temperatures.

  Compared with fixed bed and fluidized bed reactors, slurry bed reactors are easier to design heat removal methods, and can easily remove a large amount of reaction heat, which is a problem in the LPG production process. Is also easy. In the LPG synthesis reaction, since the LPG selectivity increases in a relatively narrow temperature range, it is required to strictly control the reaction temperature. Also in this respect, it is desirable to use a slurry bed reactor that can easily achieve uniform temperature conditions as compared with a fixed bed reactor and a fluidized bed reactor. In the slurry bed reaction method, it is possible to prevent a local temperature rise on the catalyst, which leads to deterioration and deactivation of the catalyst.

Thus, the slurry bed system is process advantageous. Therefore, development of a liquefied petroleum gas production catalyst suitable for use in a slurry bed reaction system is desired. However, conventional catalysts including the catalyst described in Patent Document 2 have a problem that the activity deterioration is relatively fast in the case of a slurry bed reaction system.
Japanese Patent Laid-Open No. 61-23688 International Publication No. 2007/094457 Pamphlet “Selective Synthesis of LPG from Synthesis Gas”, Kaoru Fujimoto et al. Bull. Chem. Soc. Jpn. 58, p. 3059-3060 (1985)

  The object of the present invention is to produce hydrocarbons whose main component is propane or butane, that is, liquefied petroleum gas (LPG), by reacting carbon monoxide and hydrogen with high activity, high selectivity, and high yield. It is also possible to provide a liquefied petroleum gas production catalyst having a long catalyst life and little deterioration, and particularly to provide a liquefied petroleum gas production catalyst suitable for use in a slurry bed reaction system.

  Another object of the present invention is to provide a method capable of stably producing LPG having a high concentration of propane and / or butane in a high yield from a synthesis gas over a long period of time using this catalyst. . Furthermore, it is to provide a method capable of stably producing LPG having a high propane and / or butane concentration in a high yield from a carbon-containing raw material such as natural gas over a long period of time.

  The present invention relates to the following matters.

1. A catalyst used in producing liquefied petroleum gas mainly composed of propane or butane by reacting carbon monoxide with hydrogen,
It contains a Cu—Zn-based methanol synthesis catalyst and β-zeolite (hereinafter referred to as “Pd-supported β-zeolite”) supporting Pd and one or more of Cu, Cr, Mn, or Fe. A catalyst for the production of liquefied petroleum gas.

  2. 2. The catalyst for producing a liquefied petroleum gas according to the above 1, wherein the Pd-supported β-zeolite is obtained by supporting Pd and Cu on β-zeolite.

  3. 3. The catalyst for producing a liquefied petroleum gas according to 1 or 2 above, wherein the amount of Pd supported on the Pd-supported β-zeolite is 0.05 mass% to 5 mass%.

  4). 4. The catalyst for producing a liquefied petroleum gas according to 2 or 3 above, wherein the supported amount of Cu in the Pd-supported β-zeolite is 0.1 mass% to 10 mass%.

5. The catalyst for liquefied petroleum gas production according to any one of 1 to 4 above, wherein the SiO ₂ / Al ₂ O ₃ ratio of β-zeolite as a carrier of the Pd-supported β-zeolite is 10 to 500.

  6). The Cu—Zn-based methanol synthesis catalyst is a composite oxide containing copper oxide and zinc oxide as main components or a composite oxide containing copper oxide and zinc oxide as main components and supporting one or more metals. 6. The liquefied petroleum gas production catalyst according to any one of 1 to 5 above.

7. The composite oxide is a composite oxide which contains copper oxide and zinc oxide as main components, and may further contain aluminum oxide and / or chromium oxide as an additional component,
7. The liquefied petroleum gas production catalyst according to 6 above, wherein the content ratio is copper oxide: zinc oxide: aluminum oxide: chromium oxide = 1: 0.05 to 20: 0 to 2: 0 to 2, on a mass basis.

  8). 8. The liquefied petroleum gas production catalyst according to any one of 1 to 7 above, wherein a content ratio of the Cu—Zn-based methanol synthesis catalyst and the Pd-supported β-zeolite is 4: 1 to 1: 6.

  9. A method for producing a liquefied petroleum gas comprising reacting carbon monoxide and hydrogen in the presence of the catalyst according to any one of 1 to 8 above to produce a liquefied petroleum gas whose main component is propane or butane. .

  10. A raw material gas containing carbon monoxide and hydrogen is circulated through a slurry obtained by suspending the catalyst according to any one of 1 to 8 in a solvent to produce a liquefied petroleum gas whose main component is propane or butane. A method for producing liquefied petroleum gas.

  11. The method for producing a liquefied petroleum gas as described in 10 above, wherein the solvent is a hydrocarbon having 10 to 20 carbon atoms.

12 The reaction temperature is 200 ° C. or more and 325 ° C. or less,
The reaction pressure is 1 MPa or more and 8 MPa or less,
12. The method for producing a liquefied petroleum gas according to the above 10 or 11, wherein the space velocity (feeding rate of the raw material gas per gram of catalyst in a standard state) is 100 ml / g · h or more and 50000 ml / g · h or less.

  13. The method for producing a liquefied petroleum gas according to any one of the above 10 to 12, wherein the source gas is a synthesis gas.

14 (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 liquefied petroleum gas production process for producing a liquefied petroleum gas whose main component is propane or butane by circulating a synthesis gas in a slurry in which the catalyst according to any one of 1 to 8 above is suspended in a solvent; A method for producing liquefied petroleum gas, comprising:

  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. The synthesis gas may be a coal gas obtained by coal gasification or a water gas produced from coal coke.

  When carbon monoxide and hydrogen are reacted in the presence of a catalyst containing a methanol synthesis catalyst component and a zeolite catalyst component, a reaction represented by the following formula (1) occurs, and the main component is propane or butane. Hydrocarbons, ie liquefied petroleum gas (LPG) can be produced.

まず、メタノール合成触媒成分上で一酸化炭素と水素とからメタノールが合成される。この時、メタノールの脱水２量化により、ジメチルエーテルも生成する。次いで、合成されたメタノールはゼオライト触媒成分の細孔内の活性点にて主成分がプロピレンまたはブテンである低級オレフィン炭化水素に転換される。この反応では、メタノールの脱水によってカルベン（Ｈ_２Ｃ：）が生成し、このカルベンの重合によって低級オレフィンが生成すると考えられる。そして、生成した低級オレフィンはゼオライト触媒成分の細孔内から抜け出し、メタノール合成触媒成分上で速やかに水素化されて主成分がプロパンまたはブタンであるパラフィン、すなわちＬＰＧとなる。

First, methanol is synthesized from carbon monoxide and hydrogen on a methanol synthesis catalyst component. At this time, dimethyl ether is also produced by dehydration and dimerization of methanol. Next, the synthesized methanol is converted into a lower olefin hydrocarbon whose main component is propylene or butene at active sites in the pores of the zeolite catalyst component. In this reaction, carbene (H ₂ C :) is generated by dehydration of methanol, and it is considered that a lower olefin is generated by polymerization of this carbene. The produced lower olefin escapes from the pores of the zeolite catalyst component and is quickly hydrogenated on the methanol synthesis catalyst component to become paraffin, ie, LPG, whose main component is propane or butane.

Here, the methanol synthesis catalyst component refers to one that exhibits a catalytic action in the reaction of CO + 2H ₂ → CH ₃ OH, and the zeolite catalyst component refers to a condensation reaction of methanol to hydrocarbon and / or dimethyl ether to hydrocarbon. It refers to a zeolite that exhibits catalytic action in a condensation reaction. However, the methanol synthesis catalyst component is also required to exhibit a catalytic action in the hydrogenation reaction of olefin to paraffin.

  In the present invention, a Cu-Zn-based methanol synthesis catalyst is used as the methanol synthesis catalyst component, and β-zeolite (Pd) supporting Pd and any one or more of Cu, Cr, Mn, or Fe as the zeolite catalyst component. Also referred to as supported β-zeolite).

  A catalyst containing a Cu—Zn-based methanol synthesis catalyst and β-zeolite supporting Pd has excellent catalytic performance as described above. On the other hand, in the present invention, at least one of Cu, Cr, Mn, and Fe, preferably Cu is supported on β-zeolite together with Pd. This further improves the stability and durability of the catalyst while maintaining high activity and high selectivity for propane and butane. In particular, when the catalyst is suspended in a solvent (medium oil) and used in a slurry state, that is, when the reaction is performed in a slurry bed system, the catalyst of the present invention has very little deterioration with time compared to the conventional catalyst. High stability and durability.

As described above, in the slurry bed system, the reaction heat generated on the catalyst is quickly transferred by the medium oil, so that the reaction heat can be easily removed and the temperature can be controlled as compared with the general fixed bed reaction system. On the other hand, mass transfer is relatively slow in the slurry bed system. For this reason, the present inventors have conceived that water produced as a by-product in the LPG synthesis reaction may stay on the zeolite catalyst component and degrade the catalyst, and in the reaction of CO + H ₂ O → H ₂ + CO ₂ It has been found that by directly supporting a shift catalyst component exhibiting a catalytic action on zeolite, deterioration of the catalyst can be suppressed, and stability and durability can be further improved. Solid acid zeolite catalysts are easily poisoned by water, but by directly supporting the shift catalyst component, the water on the zeolite can be reacted and removed quickly, thereby maintaining the activity of the catalyst. it is conceivable that.

The shift catalyst component is not particularly limited as long as it is a metal species that exhibits a catalytic action in the reaction of CO + H ₂ O → H ₂ + CO ₂ , and can be used. Specific examples of the shift catalyst component include one or more of Cu, Cr, Mn, and Fe, and Cu is preferable.

  Thus, the zeolite combined with the Cu—Zn-based methanol synthesis catalyst is made into β-zeolite supporting Pd and any one or more of Cu, Cr, Mn, or Fe, preferably Cu, in particular, in the slurry bed. It is possible to suppress the deterioration of the catalyst when the LPG synthesis reaction is performed in a manner. Compared with the conventional catalyst using β-zeolite supporting only Pd, the catalyst of the present invention has the same high activity and high LPG selectivity, but has very little deterioration with time and long catalyst life. Yes, suitable for use in slurry bed reaction mode. The catalyst of the present invention has an excellent catalytic performance equal to or better than that of a conventional catalyst using β-zeolite supporting only Pd even when used in a fixed bed reaction system.

  Therefore, by using the catalyst for producing liquefied petroleum gas of the present invention, particularly when performing the LPG synthesis reaction in a slurry bed system, propane and / or butane, that is, LPG is produced with high activity and high yield over a long period of time. Can do.

1. Catalyst for producing liquefied petroleum gas of the present invention The catalyst for producing liquefied petroleum gas of the present invention carries one or more Cu-Zn-based methanol synthesis catalysts and one or more of Pd and Cu, Cr, Mn or Fe. 1 type or more of (beta) -zeolite (Pd carrying | support beta-zeolite).

  In addition, the catalyst for liquefied petroleum gas manufacture of this invention may contain the other additional component in the range which does not impair the desired effect.

  The content ratio of the Cu—Zn-based methanol synthesis catalyst and the Pd-supported β-zeolite is preferably 4: 1 to 1: 6, more preferably 2: 1 to 1: 5 in terms of mass ratio. : It is especially preferable that it is 1-1: 4.

  The Cu—Zn-based methanol synthesis catalyst, which is a methanol synthesis catalyst component, has a function as a methanol synthesis catalyst and a function as an olefin hydrogenation catalyst. The zeolite catalyst component Pd-supported β-zeolite has a function as a solid acid zeolite catalyst whose acidity is adjusted with respect to the condensation reaction of methanol and / or dimethyl ether with hydrocarbons. Therefore, the content ratio of the methanol synthesis catalyst component to the zeolite catalyst component is reflected in the relative ratio between the methanol synthesis function and the olefin hydrogenation function and the hydrocarbon production function from methanol of the catalyst of the present invention. In the present invention, when producing liquefied petroleum gas whose main component is propane or butane by reacting carbon monoxide and hydrogen, carbon monoxide and hydrogen must be sufficiently converted to methanol by a methanol synthesis catalyst component. In addition, the methanol produced must be sufficiently converted by the zeolite catalyst component into an olefin whose main component is propylene or butene, and it must be converted into a liquefied petroleum gas whose main component is propane or butane by the methanol synthesis catalyst component. Don't be. By setting the content ratio of the Cu—Zn-based methanol synthesis catalyst and the Pd-supported β-zeolite within the above range, propane and / or butane can be produced with higher selectivity and higher yield.

  The content ratio of the Cu—Zn-based methanol synthesis catalyst and the Pd-supported β-zeolite is not limited to the above range, and can be determined as appropriate according to the type of methanol synthesis catalyst component, zeolite catalyst component, and the like. .

(Methanol synthesis catalyst component: Cu-Zn-based methanol synthesis catalyst)
The methanol synthesis catalyst component used in the present invention is a Cu—Zn-based methanol synthesis catalyst.

The Cu—Zn-based methanol synthesis catalyst is not particularly limited as long as it contains Cu and Zn and exhibits a catalytic action in the reaction of CO + 2H ₂ → CH ₃ OH, and a known Cu—Zn-based methanol synthesis catalyst is used. be able to. Moreover, a commercial item can also be used as a Cu-Zn type | system | group methanol synthesis catalyst.

  A general Cu—Zn-based methanol synthesis catalyst is a complex oxide (Cu—Zn complex oxide) containing copper oxide and zinc oxide as main components, or a copper oxide and zinc oxide as main components, and further oxidized as an additional component. A composite oxide containing aluminum, chromium oxide, or the like (a Cu-Zn-Al composite oxide, a Cu-Zn-Cr composite oxide, or the like).

  The Cu—Zn-based methanol synthesis catalyst used in the present invention is, for example, copper oxide: zinc oxide: aluminum oxide: chromium oxide = 1: 0.05 to 20: 0 to 2: 0 to 2 (mass basis). Is preferred.

  In the present invention, such a general Cu—Zn-based methanol synthesis catalyst (a composite oxide containing copper oxide and zinc oxide as main components, or copper oxide and zinc oxide as main components, and aluminum oxide as an additional component) In addition, for example, a composite oxide containing one or more metals can be used. The supported metal is preferably supported in a highly dispersed manner on the Cu—Zn-based methanol synthesis catalyst.

  Examples of the supported metal include Zr and V. The amount of the supported metal such as Zr of the Cu—Zn-based methanol synthesis catalyst can be determined as appropriate, but is usually preferably 8% by mass or less, and more preferably 5% by mass or less.

  A Cu—Zn-based methanol synthesis catalyst (including a metal-supported Cu—Zn-based methanol synthesis catalyst) may be used singly or in combination of two or more.

  Cu—Zn-based methanol synthesis catalysts such as Cu—Zn composite oxide, Cu—Zn—Al composite oxide, and Cu—Zn—Cr composite oxide can be prepared by a known method such as a precipitation method. In addition, a metal-supported Cu—Zn-based methanol synthesis catalyst such as Zr is prepared by a precipitation method or the like, or a commercially available Cu—Zn-based methanol synthesis catalyst is loaded with a metal such as Zr by a known method such as an impregnation method. Can be prepared.

(Zeolite catalyst component: Pd-supported β-zeolite)
The zeolite catalyst component used in the present invention is β-zeolite (referred to as Pd-supported β-zeolite) supporting Pd and one or more of Cu, Cr, Mn or Fe. As the zeolite catalyst component, β-zeolite supporting Pd and Cu is particularly preferable.

  Pd and Cu may not be included in the form of metal, and may be included in the form of oxides, nitrates, chlorides, and the like. In that case, for the purpose of obtaining higher catalytic activity, it is preferable to convert Pd and Cu into metallic palladium and metallic copper by, for example, hydrogen reduction treatment before the reaction. The treatment conditions for the reduction treatment for activating Pd and Cu can be determined as appropriate.

  Moreover, it is preferable that Pd and Cu are highly dispersed and supported on β-zeolite.

  The amount of Pd supported on the Pd-supported β-zeolite is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 0.3% by mass or more. Further, the amount of Pd supported on the Pd-supported β-zeolite is preferably 5% by mass or less, more preferably 3% by mass or less, and particularly preferably 1% by mass or less from the viewpoint of dispersibility and economy.

  The amount of Cu supported in the Pd-supported β-zeolite is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and particularly preferably 1% by mass or more. Further, the amount of Cu supported in the Pd-supported β-zeolite is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less. In order to obtain the excellent effect of the present invention, it is necessary to support a certain amount of Cu. On the other hand, if the amount of Cu supported is too large, the activity deterioration may be accelerated. .

  By setting the Pd loading and Cu loading of the Pd-supported β-zeolite within the above ranges, propane and / or butane can be stably converted over a long period of time with higher conversion, higher selectivity and higher yield. Can be manufactured.

  When any one or more of metal species other than Cu, such as Cr, Mn, or Fe, is supported, the supported amount is preferably in the same range as the above supported amount of Cu.

The β-zeolite that is a carrier of the Pd-supported β-zeolite is not particularly limited, but β-zeolite having a SiO ₂ / Al ₂ O ₃ ratio of 10 to 500 is preferable. By using β-zeolite having a SiO ₂ / Al ₂ O ₃ ratio of 10 to 500, higher catalytic activity and higher propane and butane selectivity are obtained. The SiO ₂ / Al ₂ O ₃ ratio of β-zeolite is more preferably 450 or less, and particularly preferably 400 or less. Further, the SiO ₂ / Al ₂ O ₃ ratio of β-zeolite is more preferably 20 or more, and particularly preferably 30 or more. When the catalyst of the present invention is used in a slurry bed reaction system, if the SiO ₂ / Al ₂ O ₃ ratio of β-zeolite is too low, the solvent tends to decompose. Therefore, the SiO ₂ / Al ₂ O ₃ ratio of β-zeolite is more preferably 200 or more, and particularly preferably 300 or more.

  The Pd-supported β-zeolite used in the present invention may be one in which a metal other than the above-mentioned Pd and Cu is supported on β-zeolite as long as the desired effect is not impaired.

  Pd carrying | support beta-zeolite may use 1 type, or may use 2 or more types together.

  Pd-supported β-zeolite in which Pd and Cu are supported on β-zeolite can be prepared by supporting a metal such as Pd and Cu on β-zeolite by a known method such as an impregnation method or an ion exchange method. Moreover, beta-zeolite can be prepared by a well-known method, and a commercial item can also be used for it.

2. Production method of catalyst for production of liquefied petroleum gas of the present invention Production method of catalyst for production of liquefied petroleum gas of the present invention includes a Cu-Zn-based methanol synthesis catalyst that is a methanol synthesis catalyst component and a Pd-supported β that is a zeolite catalyst component. -It is preferable to prepare zeolite separately and mix them. By separately preparing the methanol synthesis catalyst component and the zeolite catalyst component, it is possible to easily design each composition, structure, and physical property optimally for each function.

  The Cu—Zn-based methanol synthesis catalyst can be prepared by a known method as described above. Moreover, a commercial item can also be used.

  Some methanol synthesis catalyst components need to be activated by reduction before use. In the present invention, it is not always necessary to reduce and activate the methanol synthesis catalyst component in advance, and the methanol synthesis catalyst component and the zeolite catalyst component are mixed and molded to produce the liquefied petroleum gas production catalyst of the present invention. Thereafter, prior to the start of the reaction, a reduction treatment can be performed to activate the methanol synthesis catalyst component. The treatment conditions for the reduction treatment can be appropriately determined according to the type of methanol synthesis catalyst component.

  As described above, Pd-supported β-zeolite as a zeolite catalyst component can also be prepared by a known method.

  The liquefied petroleum gas production catalyst of the present invention is produced by uniformly mixing a methanol synthesis catalyst component and a zeolite catalyst component, and then molding the catalyst as necessary. 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 process, the compound moves between the two catalyst components, for example, the basic component in the methanol synthesis catalyst component moves to the acid point in the zeolite catalyst component and is neutralized. As a result, the physical properties optimized for the respective functions of both catalyst components may change. Examples of the catalyst molding method include an extrusion molding method and a tableting molding method.

  In the present invention, when the methanol synthesis catalyst component and the zeolite catalyst component to be mixed are used in a fixed bed reaction method, it is preferable that the particle size is somewhat large, and specifically, the particle size is preferably 100 μm or more. The catalyst for liquefied petroleum gas production of the present invention obtained by mixing a methanol synthesis catalyst component having a particle size of 100 μm or more and a zeolite catalyst component having a particle size of 100 μm or more and molding as necessary, has a particle size of Compared with a catalyst obtained by mixing a methanol synthesis catalyst component and a zeolite catalyst component with a small amount, the catalyst activity and the yield of LPG may be increased.

  In this case, the particle size of the methanol synthesis catalyst component to be mixed and the particle size of the zeolite catalyst component are more preferably 200 μm or more, and particularly preferably 500 μm or more. On the other hand, from the viewpoint of maintaining the excellent performance of the mixed catalyst of the present invention, the particle size of the methanol synthesis catalyst component to be mixed and the particle size of the zeolite catalyst component are preferably 5 mm or less, and more preferably 3 mm or less.

  On the other hand, when the mixed catalyst of the present invention is used in a slurry bed reaction system, the particle size of the methanol synthesis catalyst component and the particle size of the zeolite catalyst component are preferably relatively small, specifically, the particle size is 400 μm or less. Preferably, it is 200 μm or less, more preferably 1 to 100 μm, and particularly preferably 1 to 50 μm.

  Whether used in a fixed bed reaction system or a slurry bed reaction system, it is preferable that the methanol synthesis catalyst component and the zeolite catalyst component to be mixed have the same particle size.

  When producing a mixed catalyst, usually, each catalyst component is mechanically pulverized as necessary, and after the particle size is adjusted to, for example, about 0.5 to 2 μm, it is uniformly mixed and shaped as necessary. . Alternatively, all the desired catalyst components are added, mixed while being mechanically pulverized until uniform, and the particle size is adjusted to about 0.5 to 2 μm, for example, and molded as necessary.

  On the other hand, when the methanol synthesis catalyst component having a particle size of 100 μm or more and the zeolite catalyst component having a particle size of 100 μm or more are mixed to produce the liquefied petroleum gas production catalyst of the present invention, each catalyst component is usually added. Molded in advance by a known molding method such as tableting or extrusion, mechanically pulverized as necessary, and after the particle size is preferably adjusted to about 100 μm to 5 mm, both are mixed uniformly. To do. And this mixture is shape | molded again as needed, and the catalyst for liquefied petroleum gas manufacture of this invention is manufactured.

3. Next, carbon monoxide and hydrogen are reacted using the catalyst for producing a liquefied petroleum gas of the present invention as described above, and a liquefied petroleum gas whose main component is propane or butane, preferably main A method for producing liquefied petroleum gas whose component is propane will be described.

  The synthesis reaction of LPG can be carried out in various reaction formats such as a fixed bed method, a fluidized bed method, and a slurry bed method. As described above, in the present invention, the LPG synthesis reaction is preferably carried out.

  When the reaction is carried out in a slurry bed system, the catalyst of the present invention is dispersed in a medium oil as a solvent and used in a slurry state. Then, a raw material gas containing carbon monoxide and hydrogen is circulated in the catalyst slurry to synthesize LPG.

  The medium oil used in the present invention is (1) stable and inert under reaction conditions, (2) can stably maintain a liquid state under reaction conditions, and (3) carbon monoxide as a reaction raw material and Any of those having high hydrogen solubility can be used. Examples of the medium oil include aliphatic, aromatic or alicyclic hydrocarbons, alcohols, ethers, esters, ketones, and halides thereof, and those containing hydrocarbons as a main component are preferable. Particularly preferred is a hydrocarbon having 10 to 20 carbon atoms. One medium oil may be used, or two or more medium oils may be mixed and used. As the medium oil, light oil from which sulfur content has been removed, vacuum gas oil, hydrotreated coal tar high boiling fraction, Fischer-Tropsch synthetic oil, high boiling food oil, and the like can also be used.

  The amount of the catalyst of the present invention can be appropriately determined according to the type of solvent (medium oil) to be used, reaction conditions, etc., but is usually preferably about 1 to 50% by weight, preferably 5 to 40% by weight with respect to the solvent. % Is more preferable.

  Reaction conditions such as the raw material gas composition, reaction temperature, reaction pressure, and contact time with the catalyst can be appropriately determined. For example, the reaction can be performed under the following conditions.

  The concentration of carbon monoxide in the gas fed to the reactor is not particularly limited, but is preferably 20 mol% to 45 mol%, more preferably 25 mol% to 40 mol%.

  The concentration of hydrogen in the gas fed to the reactor is not particularly limited, but is preferably 1.2 mol or more with respect to 1 mol of carbon monoxide because carbon monoxide reacts more sufficiently. 5 mol 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 2.5 mol or less with respect to 1 mol of carbon monoxide, from the viewpoint of economy.

  The gas fed into the reactor may contain components other than carbon monoxide and hydrogen, such as carbon dioxide and an inert gas such as Ar.

  The reaction temperature is preferably 200 ° C. or higher, more preferably 260 ° C. or higher, and particularly preferably 270 ° C. or higher. By setting the reaction temperature within the above range, higher catalyst activity and LPG selectivity can be obtained, and propane and / or butane can be produced in a high yield. On the other hand, the reaction temperature is preferably 325 ° C. or lower, more preferably 315 ° C. or lower, particularly preferably 310 ° C. or lower, from the viewpoint of the stability and durability of the catalyst.

  The reaction pressure is preferably 1 MPa or more, more preferably 2 MPa or more, and particularly preferably 2.5 MPa or more from the viewpoint of obtaining higher catalytic activity. On the other hand, the reaction pressure is preferably 10 MPa or less, more preferably 8 MPa or less, from the viewpoint of economy.

  The space velocity (the feed rate of the raw material gas per gram of catalyst in a standard state) is preferably 100 to 50000 ml / g · h, and more preferably 500 to 30000 ml / g · h. By setting the space velocity to 50000 ml / g · h or less, the conversion rate of carbon monoxide becomes higher. On the other hand, it is preferable that the space velocity is 100 ml / g · h or more from the viewpoint of economy.

  In this way, by using the catalyst for producing liquefied petroleum gas according to the present invention, carbon monoxide and hydrogen are reacted in a slurry bed system, whereby a hydrocarbon whose main component is propane or butane, that is, liquefied petroleum gas (LPG). ) Can be obtained.

  Further, by using the catalyst for producing liquefied petroleum gas according to the present invention and reacting carbon monoxide and hydrogen in a fixed bed system, a fluidized bed system or the like, a hydrocarbon whose main component is propane or butane, that is, liquefied petroleum Gas (LPG) can be obtained. In this case, the LPG synthesis reaction can be performed according to the method described in International Publication No. 2007/094457.

4). Method for producing liquefied petroleum gas from carbon-containing raw material In the present invention, a synthetic gas can be used as a raw material gas for liquefied petroleum gas (LPG) synthesis.

  Next, synthesis gas is produced from the carbon-containing raw material (synthesis gas production process), and LPG is produced from the obtained synthesis gas using the catalyst of the invention (liquefied petroleum gas production process). An embodiment of the manufacturing method will be described.

[Syngas production process]
In the synthesis gas production process, 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 .

As the carbon-containing raw material, a substance containing carbon and capable of generating H ₂ and CO by reacting with at least one selected from the group consisting of H ₂ O, O ₂ and CO ₂ can be used. . As the carbon-containing raw material, those known as raw materials for synthesis gas can be used. For example, lower hydrocarbons such as methane and ethane, natural gas, naphtha, coal, and the like can be used.

  In the present invention, since a catalyst is usually used in the synthesis gas production process and the liquefied petroleum gas production process, the carbon-containing raw material (natural gas, naphtha, coal, etc.) contains catalyst poisoning substances such as sulfur and sulfur compounds. Those with less are preferred. Moreover, when a catalyst poisoning substance is contained in the carbon-containing raw material, a step of removing the catalyst poisoning substance such as desulfurization can be performed prior to the synthesis gas production process, if necessary.

The synthesis gas reacts the carbon-containing raw material as described above with at least one selected from the group consisting of H ₂ O, O ₂ and CO _{2 in} the presence of a synthesis gas production catalyst (reforming catalyst). It is manufactured by.

  Syngas can be produced by a known method. For example, when natural gas (methane) is used as a raw material, synthesis gas can be produced by a steam reforming method, an autothermal reforming method, or the like. In this case, steam necessary for steam reforming, oxygen necessary for autothermal reforming, and the like can be supplied as necessary. In addition, when coal is used as a raw material, synthesis gas can be produced using an air-blown gasification furnace or the like.

In addition, for example, a shift reactor is provided downstream of a reformer that is a reactor for producing synthesis gas from the above raw materials, 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 present invention, the composition of a preferred synthesis gas produced from the synthesis gas production process is such that the molar ratio of H ₂ / CO is 7 / 3≈2.3 in terms of the stoichiometry for producing lower paraffin. The content ratio of hydrogen to carbon monoxide (H ₂ / CO; molar basis) in the produced synthesis gas is preferably 1.2 to 3. Since hydrogen is generated by the shift reaction with water generated in the conversion reaction from synthesis gas to LPG, the content ratio of hydrogen to carbon monoxide in the synthesis gas (H ₂ / CO ; On a molar basis) is preferably 1.2 or more, more preferably 1.5 or more. In addition, hydrogen is sufficient if carbon monoxide reacts favorably and liquefied petroleum gas whose main component is propane or butane can be obtained, and surplus hydrogen unnecessarily raises the total pressure of the raw material gas. This will reduce the economics of the technology. In this respect, the content ratio of hydrogen to carbon monoxide in the synthesis gas (H ₂ / CO; on a molar basis) is preferably 3 or less, and more preferably 2.5 or less.

  Further, the concentration of carbon monoxide in the produced synthesis gas is 20 from the viewpoint of securing the pressure (partial pressure) of carbon monoxide suitable for the conversion reaction from synthesis gas to LPG and improving the raw material basic unit. The mol% or more is preferable, and 25 mol% or more is more preferable. The concentration of carbon monoxide in the produced synthesis gas is preferably 45 mol% or less, preferably 40 mol% or less from the viewpoint that the conversion rate of carbon monoxide is sufficiently higher in the conversion reaction from synthesis gas to LPG. The following is more preferable.

  In order to produce the synthesis gas having the above composition, the supply ratio between the carbon-containing raw material and steam (water), at least one selected from the group consisting of oxygen and carbon dioxide, the type of synthesis gas production catalyst used, Other reaction conditions may be selected as appropriate.

For example, a gas having a composition such that steam / methane (molar ratio) is 1 and carbon dioxide / methane (molar ratio) is 0.4 as a raw material gas is filled with Ru or Rh / sintered low surface area magnesia catalyst. In an externally heated multi-tube reaction tube type apparatus, the reaction temperature (catalyst layer outlet temperature) is 800 to 900 ° C., the reaction pressure is 1 to 4 MPa, the gas space velocity (GHSV) is 2000 hr ^{−1 and the} like. Gas can be produced.

  When reforming using steam in the synthesis gas production, the ratio of steam to raw carbon (S / C) is preferably 1.5 or less from the viewpoint of energy efficiency, More preferably. On the other hand, if S / C is set to such a low value, the possibility of carbon deposition cannot be ignored.

  When syngas production is performed at low S / C, for example, good synthesis gasification as described in WO98 / 46524, JP2000-288394A or JP2000-469A It is preferable to use a catalyst having a reaction activity but having a suppressed carbon deposition activity. Hereinafter, these catalysts will be described.

The catalyst described in WO98 / 46524 is a catalyst in which at least one catalyst metal selected from rhodium, ruthenium, iridium, palladium and platinum is supported on a support made of a metal oxide, The specific surface area of the catalyst is 25 m ² / g or less, the electronegativity of the metal ions in the support metal oxide is 13.0 or less, and the supported amount of the catalyst metal is a metal equivalent amount in the support metal oxide. It is a catalyst which is 0.0005 to 0.1 mol% with respect to. From the viewpoint of preventing carbon deposition, the electronegativity is preferably 4 to 12, and the specific surface area of the catalyst is preferably 0.01 to 10 m ² / g.

  The electronegativity of the metal ions in the metal oxide is defined by the following formula.

Xi = (1 + 2i) Xo
Here, Xi: electronegativity of metal ion, Xo: electronegativity of metal, i: number of valence electrons of metal ion.

  When the metal oxide is a composite metal oxide, the average metal ion electronegativity is used, and the value is determined based on the electronegativity of each metal ion contained in the composite metal oxide. The sum of the product multiplied by the mole fraction of the product.

  Pauling's electronegativity is used for the metal electronegativity (Xo). For Pauling's electronegativity, the values listed in Table 15.4 of “Ryoichi Fujishiro, Moore Physical Chemistry (lower) (4th edition), Tokyo Kagaku Dojin, p.707 (1974)” are used. The electronegativity (Xi) of metal ions in the metal oxide is described in detail, for example, in “Catalyst Society, Catalyst Course, Vol. 2, p. 145 (1985)”.

  In this catalyst, examples of the metal oxide include metal oxides containing one or more metals such as Mg, Ca, Ba, Zn, Al, Zr, and La. An example of such a metal oxide is magnesia (MgO).

  In the case of a method of reacting methane and steam (steam reforming), the reaction is represented by the following formula (i).

メタンと二酸化炭素とを反応させる方法（ＣＯ_２リフォーミング）の場合、その反応は下記式（ii）で示される。

In the case of a method of reacting methane and carbon dioxide (CO ₂ reforming), the reaction is represented by the following formula (ii).

メタンとスチームと二酸化炭素とを反応させる方法（スチーム／ＣＯ_２混合リフォーミング）の場合、その反応は下記式（iii）で示される。

In the case of a method of reacting methane, steam and carbon dioxide (steam / CO ₂ mixed reforming), the reaction is represented by the following formula (iii).

上記の触媒を用いてスチームリフォーミングを行う場合、その反応温度は、好ましくは６００〜１２００℃、より好ましくは６００〜１０００℃であり、その反応圧力は、好ましくは０．０９８ＭＰａＧ〜３．９ＭＰａＧ、より好ましくは０．４９ＭＰａＧ〜２．９ＭＰａＧ（Ｇはゲージ圧であることを示す）である。また、このスチームリフォーミングを固定床方式で行う場合、そのガス空間速度（ＧＨＳＶ）は、好ましくは１，０００〜１０，０００ｈｒ^−１、より好ましくは２，０００〜８，０００ｈｒ^−１である。含炭素原料に対するスチームの使用割合を示すと、含炭素原料（ＣＯ_２を除く）中の炭素１モル当り、好ましくはスチーム（Ｈ_２Ｏ）０．５〜２モル、より好ましくは０．５〜１．５モル、さらに好ましくは０．８〜１．２モルの割合である。

When steam reforming is performed using the above catalyst, the reaction temperature is preferably 600 to 1200 ° C., more preferably 600 to 1000 ° C., and the reaction pressure is preferably 0.098 MPaG to 3.9 MPaG, More preferably, it is 0.49 MPaG to 2.9 MPaG (G indicates a gauge pressure). Also, when performing the steam reforming with a fixed bed, a gas space velocity (GHSV) is preferably 1,000～10,000Hr ^-1, more preferably 2,000~8,000hr ^-1. When the proportion of steam used relative to the carbon-containing raw material is shown, preferably 0.5 to 2 mol of steam (H ₂ O), more preferably 0.5 to 1 mol per carbon in the carbon-containing raw material (excluding CO ₂ ). The ratio is 1.5 mol, more preferably 0.8 to 1.2 mol.

When CO ₂ reforming is performed using the above catalyst, the reaction temperature is preferably 500 to 1200 ° C., more preferably 600 to 1000 ° C., and the reaction pressure is preferably 0.49 MPaG to 3.9 MPaG. More preferably, it is 0.49 MPaG-2.9 MPaG. When performing the CO ₂ reforming a fixed bed, a gas space velocity (GHSV) is preferably 1,000～10,000Hr ^-1, more preferably 2,000～8,000Hr ^-1 . When the use ratio of CO ₂ with respect to the carbon-containing raw material is shown, it is preferably _{20 to} 0.5 mol of CO ₂ , more preferably 10 to 1 mol per mol of carbon in the carbon-containing raw material (excluding CO ₂ ). is there.

When the above catalyst is used to produce a synthesis gas by reacting a carbon-containing raw material with a mixture of steam and CO ₂ (performing steam / CO ₂ reforming), the mixing ratio of steam and CO ₂ is particularly Although not limited, in general, H ₂ O / CO ₂ (molar ratio) is 0.1 to 10, and the reaction temperature is preferably 550 to 1200 ° C., more preferably 600 to 1000 ° C. The reaction pressure is preferably 0.29 MPaG to 3.9 MPaG, more preferably 0.49 MPaG to 2.9 MPaG. When performing the reaction in a fixed bed, a gas space velocity (GHSV) is preferably 1,000～10,000Hr ^-1, more preferably 2,000~8,000hr ^-1. When the proportion of steam used relative to the carbon-containing raw material is shown, preferably 0.5 to 2 mol of steam (H ₂ O), more preferably 0.5 to 1 mol per carbon in the carbon-containing raw material (excluding CO ₂ ). The ratio is 1.5 mol, more preferably 0.5 to 1.2 mol.

The catalyst described in Japanese Patent Application Laid-Open No. 2000-288394 is composed of a complex oxide having a composition represented by the following formula (I), and M ¹ and Co are highly dispersed in the complex oxide. It is a catalyst characterized by this.

a ¹ M ¹ · b ¹ Co · c ¹ Mg · d ¹ Ca · e ¹ O (I)
(Wherein a ¹ , b ¹ , c ¹ , d ¹ and e ¹ are molar fractions, a ¹ + b ¹ + c ¹ + d ¹ = ^1, 0.0001 ≦ a ¹ ≦ 0.10, 0.0001 ≦ b ¹ ≦ 0.20, 0.70 ≦ (c ¹ + d ¹ ) ≦ 0.9998, 0 <c ¹ ≦ 0.9998, 0 ≦ d ¹ <0.9998, and e ¹ is an element of oxygen This is the number necessary to maintain charge balance.

M ¹ is at least one element selected from Group 6A elements, Group 7A elements, Group 8 transition elements excluding Co, Group 1B elements, Group 2B elements, Group 4B elements, and lanthanoid elements. It is. )
The catalyst described in Japanese Patent Application Laid-Open No. 2000-469 is composed of a complex oxide having a composition represented by the following formula (II), and M ² and Ni are highly dispersed in the complex oxide. It is a catalyst characterized by this.

a ² M ² · b ² Ni · c ² Mg · d ² Ca · e ² O (II)
(Wherein a ² , b ² , c ² , d ² , and e ² are molar fractions, and a ² + b ² + c ² + d ² = 1, 0.0001 ≦ a ² ≦ 0.10, 0.0001 ≦ b ² ≦ 0.10, 0.80 ≦ (c ² + d ² ) ≦ 0.9998, 0 <c ² ≦ 0.9998, 0 ≦ d ² <0.9998, and e ² is an element of oxygen This is the number necessary to maintain charge balance.

M ² is at least one element of Group 3B element, Group 4A element, Group 6B element, Group 7B element, Group 1A element, and lanthanoid element of the periodic table. )
These catalysts can also be used in the same manner as the catalyst described in WO98 / 46524.

  The reforming reaction of the carbon-containing raw material, that is, the synthesis reaction of the synthesis gas is not limited to the above method, and may be performed according to other known methods. The reforming reaction of the carbon-containing raw material can be carried out in various types of reactors, but usually it is preferably carried out in a fixed bed system or a fluidized bed system.

[Liquefied petroleum gas production process]
In the liquefied petroleum gas production process, using the liquefied petroleum gas production catalyst of the present invention, from the synthesis gas obtained in the above synthesis gas production process, the main component of the hydrocarbon contained is propane or butane containing lower paraffin Produce gas. Then, after separating moisture or the like from the obtained lower paraffin-containing gas, if necessary, low boiling point components (substances having a boiling point or sublimation point lower than that of propane or hydrogen and monoxide which are unreacted raw materials) Carbon, by-products such as carbon dioxide, ethane, ethylene and methane) and high-boiling components (both by-product high-boiling paraffin gas) that have a boiling point higher than that of butane are separated as necessary. To obtain liquefied petroleum gas (LPG) mainly composed of propane or butane. Moreover, in order to obtain liquefied petroleum gas, you may pressurize and / or cool as needed.

  In the liquefied petroleum gas production process, carbon monoxide and hydrogen are reacted in the presence of the liquefied petroleum gas production catalyst of the present invention as described above, and paraffins whose main component is propane or butane, preferably the main component is present. Propane, which is propane, is produced.

  Here, the gas fed into the reactor is the synthesis gas obtained in the above synthesis gas production process. The gas fed into the reactor may be a gas obtained by adding carbon monoxide, hydrogen, or other components to the synthesis gas obtained in the above synthesis gas production process, if necessary. Further, the gas fed into the reactor may be a gas obtained by separating a predetermined component from the synthesis gas obtained in the above synthesis gas production process, if necessary.

  The lower paraffin-containing gas synthesis reaction (LPG synthesis reaction) using the catalyst of the present invention is preferably performed in a slurry bed system under the reaction conditions as described above.

  In the lower paraffin-containing gas obtained in this liquefied petroleum gas production process, 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, a lower paraffin-containing gas having a total content of propane and butane of 60% or more, further 70% or more, more preferably 75% or more (including 100%) based on the carbon content of the hydrocarbons contained. Obtainable.

  Furthermore, the lower paraffin-containing gas obtained in the liquefied petroleum gas production process preferably has more propane than butane from the viewpoint of combustibility and vapor pressure characteristics.

  The lower paraffin-containing gas obtained in the liquefied petroleum gas production process usually contains moisture, a low-boiling component 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. included. Examples of the low boiling point component include ethane, methane, and ethylene as by-products, carbon dioxide generated by a shift reaction, hydrogen and carbon monoxide as unreacted raw materials. 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.

  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 solution 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.

  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 thus produced can be 90 mol% or more, and further 95 mol% or more (including 100 mol%).

  In the present invention, the low-boiling component separated from the lower paraffin-containing gas can be recycled as a raw material for the synthesis gas production process.

The low-boiling components separated from the lower paraffin-containing gas include substances that can be reused as raw materials for the synthesis gas production process, specifically methane, ethane, ethylene, and the like. Further, carbon dioxide contained in the low boiling point component can be returned to the synthesis gas by the CO ₂ reforming reaction. Furthermore, the low boiling point component contains hydrogen and carbon monoxide which are unreacted raw materials. Therefore, the raw material intensity can be reduced by recycling the low boiling point component separated from the lower paraffin-containing gas 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 the synthesis gas production process, the content of low-boiling components in the gas sent to the reformer, which is a reactor, that is, the content of recycled raw materials can be determined as appropriate, for example, 40 to 75 mol%. be able to.

  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.

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

[Example 1]
(Manufacture of catalyst)
As the methanol synthesis catalyst component, a commercially available Cu—Zn-based methanol synthesis catalyst (Cu—Zn—Al composite oxide) was used.

As a zeolite catalyst component, a commercially available proton type β-zeolite having a SiO ₂ / Al ₂ O ₃ ratio of 350 (manufactured by Zeolst International) was impregnated with 0.5% by weight of Pd and 1. A Cu—Pd / β-zeolite carrying 35% by weight of Cu was used.

First, a predetermined amount of Cu (NO ₃ ) ₂ .3H ₂ O and ion-exchanged water are added to a predetermined amount of Pd (NH ₃ ) ₂ (NO ₃ ) ₂ solution and dissolved, and 7 ml of a Cu—Pd-containing solution ( Cu concentration: 7.56% by weight, Pd concentration: 0.75% by weight). Then, 10 g of β-zeolite calcined at 500 ° C. for 4 hours was added to the prepared Cu—Pd-containing solution and stirred for 1 hour to be impregnated. Thereafter, the solvent was evaporated by drying under reduced pressure at 65 ° C., and the obtained Cu—Pd-supported β-zeolite was dried at 120 ° C. for 8 hours and then calcined at 500 ° C. for 4 hours. Then, this was mechanically pulverized to obtain Cu-Pd-supported β-zeolite (hereinafter also referred to as “Cu-Pd / β-zeolite”).

  Then, a Cu—Zn-based methanol synthesis catalyst (hereinafter also referred to as “Cu—Zn”) and the prepared Cu—Pd / β-zeolite are combined as follows: Cu—Zn: Cu—Pd / β-zeolite = 1: 4. The mixture was uniformly pulverized and mixed at a weight ratio of about 355 μm or less to obtain a liquefied petroleum gas production catalyst.

(Manufacturing LPG)
The LPG synthesis reaction was performed using the stirring type slurry bed high-temperature and high-pressure reactor shown in FIG. A band heater was attached to the reactor, and the surrounding area was covered with a heat insulating cover. The temperature of the band heater was measured with a thermocouple inserted between the reactors. The temperature in the reactor was measured with a thermocouple inserted into the reactor, and PID control was performed.

Prior to the reaction, the prepared catalyst was reduced at a normal pressure and 300 ° C. for 8 hours in a hydrogen / nitrogen mixed gas stream (H ₂ / N ₂ = 5/95; flow rate: 100 ml / min.).

  First, 50 ml (38.65 g) of n-hexadecane was added as a solvent in the reactor. Next, 5 g of the reduced catalyst was placed in a solvent under a nitrogen atmosphere, and the reactor was installed in the apparatus.

First, N ₂ was added at 100 ml / min. The pressure was raised to 3.5 MPa, N ₂ was stopped, and a raw material gas having a composition of CO: H ₂ : CO ₂ : Ar = 32: 60: 5: 3 (molar ratio) was 80 ml / min. The pressure was increased to 3.5 MPa while flowing at a flow rate of. Stirring was started and the catalyst was suspended in a solvent to form a slurry, and then the temperature was raised to 280 ° C. over 2 hours while stirring to initiate the reaction. At this time, the mixture was stirred at 200 rpm up to 200 ° C. and 1050 rpm up to 280 ° C. The reaction conditions for the LPG synthesis reaction were a reaction temperature of 280 ° C., a reaction pressure of 3.5 MPa, and a space velocity (feeding rate of the raw material gas per gram of catalyst in a standard state) of 960 ml / g · h.

  At predetermined times during the reaction, the product gas was analyzed using gas chromatography connected online. After the analysis was completed, the temperature was lowered under the reaction gas flow, and then the reaction gas was stopped and the pressure was reduced. After stopping the reaction, the catalyst and the solvent were sampled.

The gas chromatography used was GC-8A (manufactured by Shimadzu Corporation), and FID was used as a detector for analysis of hydrocarbons and DME. The column used Propack-Q as the packing material, and the temperature was 60 to 170 ° C. He was used as the carrier gas. TCD was used for the analysis of CO, CO ₂ , CH ₄ and Ar. The column used activated carbon as the packing material, and the temperature was 90 ° C. He was used as the carrier gas.

Changes over time in the yield of hydrocarbon (HC), dimethyl ether (DME), and carbon dioxide (CO ₂ ) are shown in FIG. 2, and changes over time in the composition of the generated hydrocarbon are shown in FIG. .

“CO conversion rate (%)”, “Hydrocarbon yield (%)”, “CO ₂ yield (%)”, “DME yield (%)”, “Hydrocarbon composition (%)” Is defined as:

The CO conversion rate indicates the ratio of CO in the raw material gas converted into a product.
CO conversion (%) = [(CO flow rate at the inlet−CO flow rate at the outlet) / (CO flow rate at the inlet)] × 100.

The yields of hydrocarbons, CO ₂ , and DME are the percentages of each product obtained from all raw materials on a carbon basis.
Hydrocarbon yield (%) = CO conversion (%) × hydrocarbon selectivity (%) × 100,
CO ₂ yield (%) = CO conversion (%) × CO ₂ selectivity (%) × 100,
DME yield (%) = CO conversion (%) × DME selectivity (%) × 100.

The composition of the hydrocarbon indicates the content of each hydrocarbon in the total generated hydrocarbon on a carbon basis. For example, the C3 hydrocarbon content is calculated as follows.
C3 (%) in all hydrocarbons = [(FID area of C3) / (FID area of C1 + FID area of C2 + FID area of C3 + FID area of C4 + FID area of C5 + FID area of C6 + ...)] × 100 (FID area: peak area of gas chromatography).

[Comparative Example 1]
(Manufacture of catalyst)
As the methanol synthesis catalyst component, the same commercially available Cu—Zn-based methanol synthesis catalyst as that used in Example 1 was used.

As the zeolite catalyst component, 0.5 wt% of the same commercially available SiO ₂ / Al ₂ O ₃ ratio as used in Example 1 having a ratio of 350 to 350 β-zeolite by an ion exchange method was used. Pd / β-zeolite carrying Pd was used.

First, ion-exchanged water was added to a predetermined amount of Pd (NH ₃ ) ₂ (NO ₃ ) ₂ solution, which was stirred in a 60 ° C. hot water bath for 30 minutes, and 150 ml of Pd-containing solution (concentration: 0.027 weight). %) Was prepared. Then, 8 g of β-zeolite calcined at 500 ° C. for 4 hours was slowly added to the prepared Pd-containing solution, and heated and stirred at 60 ° C. for 8 hours. Thereafter, filtration of the sample and washing with ion-exchanged water were repeated three times.

  The Pd-supported β-zeolite thus obtained was dried at 120 ° C. for 8 hours and then calcined at 500 ° C. for 4 hours. This was mechanically pulverized to obtain Pd-supported β-zeolite (hereinafter also referred to as “Pd / β-zeolite”).

  Then, a Cu—Zn-based methanol synthesis catalyst (hereinafter also referred to as “Cu—Zn”) and the prepared Pd / β-zeolite are mixed with Cu—Zn: Pd / β-zeolite = 1: 4 (weight ratio). Then, the mixture was uniformly pulverized and mixed, and molded to about 355 μm or less to obtain a liquefied petroleum gas production catalyst.

(Manufacturing LPG)
Using the prepared catalyst, an LPG synthesis reaction was performed in the same manner as in Example 1, and the product was analyzed by gas chromatography.

The time course of the yield of hydrocarbon (HC), the yield of dimethyl ether (DME), and the yield of carbon dioxide (CO ₂ ) is shown in FIG. 4, and the time course of the composition of the generated hydrocarbon is shown in FIG. .

  As described above, the catalyst for producing liquefied petroleum gas according to the present invention reacts with carbon monoxide and hydrogen to produce hydrocarbons whose main component is propane or butane, that is, liquefied petroleum gas (LPG) with high activity and high selectivity. In addition, the catalyst has a long catalyst life and little deterioration, and is particularly suitable for use in a slurry bed reaction system. By using the catalyst of the present invention, LPG can be produced stably and with high activity, high selectivity and high yield from a carbon-containing raw material such as natural gas or synthesis gas over a long period of time.

It is a figure which shows an example of the reaction apparatus suitable for enforcing the manufacturing method of LPG of this invention. The yield of hydrocarbon (HC), the yield of dimethyl ether (DME), and carbon dioxide in the LPG synthesis reaction using the (Cu—Zn-based methanol synthesis catalyst + Cu—Pd / β-zeolite) catalyst of Example 1 is a graph showing the time course of the yield of (CO _2). 2 is a graph showing a change over time in the composition of the generated hydrocarbon in the LPG synthesis reaction using the (Cu—Zn-based methanol synthesis catalyst + Cu—Pd / β-zeolite) catalyst of Example 1. FIG. In the LPG synthesis reaction using the (Cu—Zn-based methanol synthesis catalyst + Pd / β-zeolite) catalyst of Comparative Example 1, the yield of hydrocarbon (HC), the yield of dimethyl ether (DME), and carbon dioxide (CO It is a graph which shows a time-dependent change of the yield of ₂ ). 6 is a graph showing a change with time of the composition of the generated hydrocarbon in the LPG synthesis reaction using the (Cu—Zn-based methanol synthesis catalyst + Pd / β-zeolite) catalyst of Comparative Example 1;

Claims (14)

A catalyst used in producing liquefied petroleum gas mainly composed of propane or butane by reacting carbon monoxide with hydrogen,
It contains a Cu—Zn-based methanol synthesis catalyst and β-zeolite (hereinafter referred to as “Pd-supported β-zeolite”) supporting Pd and one or more of Cu, Cr, Mn, or Fe. A catalyst for the production of liquefied petroleum gas.   The catalyst for producing a liquefied petroleum gas according to claim 1, wherein the Pd-supported β-zeolite is obtained by supporting Pd and Cu on β-zeolite.   The catalyst for producing a liquefied petroleum gas according to claim 1 or 2, wherein the Pd supported amount of the Pd-supported β-zeolite is 0.05 mass% to 5 mass%.   The catalyst for producing a liquefied petroleum gas according to claim 2 or 3, wherein the supported amount of Cu in the Pd-supported β-zeolite is 0.1 mass% to 10 mass%. The catalyst for liquefied petroleum gas production according to any one of claims 1 to 4, wherein the Pd-supported β-zeolite, which is a carrier of β-zeolite, has a SiO ₂ / Al ₂ O ₃ ratio of 10 to 500.   The Cu—Zn-based methanol synthesis catalyst is a composite oxide containing copper oxide and zinc oxide as main components or a composite oxide containing copper oxide and zinc oxide as main components and supporting one or more metals. The catalyst for liquefied petroleum gas manufacture in any one of Claims 1-5. The composite oxide is a composite oxide which contains copper oxide and zinc oxide as main components, and may further contain aluminum oxide and / or chromium oxide as an additional component,
The catalyst for liquefied petroleum gas production according to claim 6, wherein the content ratio is copper oxide: zinc oxide: aluminum oxide: chromium oxide = 1: 0.05 to 20: 0 to 2: 0 to 2 on a mass basis. .   The catalyst for producing liquefied petroleum gas according to any one of claims 1 to 7, wherein a content ratio of the Cu-Zn-based methanol synthesis catalyst and the Pd-supported β-zeolite is 4: 1 to 1: 6. .   Production of liquefied petroleum gas, wherein carbon monoxide and hydrogen are reacted in the presence of the catalyst according to any one of claims 1 to 8 to produce liquefied petroleum gas whose main component is propane or butane. Method.   A raw material gas containing carbon monoxide and hydrogen is circulated in a slurry obtained by suspending the catalyst according to any one of claims 1 to 8 in a solvent to produce a liquefied petroleum gas whose main component is propane or butane. A method for producing liquefied petroleum gas, comprising:   The method for producing liquefied petroleum gas according to claim 10, wherein the solvent is a hydrocarbon having 10 to 20 carbon atoms. The reaction temperature is 200 ° C. or more and 325 ° C. or less,
The reaction pressure is 1 MPa or more and 8 MPa or less,
The method for producing a liquefied petroleum gas according to claim 10 or 11, wherein a space velocity (feeding rate of the raw material gas per 1 g of catalyst in a standard state) is 100 ml / g · h or more and 50000 ml / g · h or less.   The method for producing a liquefied petroleum gas according to any one of claims 10 to 12, wherein the raw material gas is a synthesis gas. (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 liquefied petroleum gas production process for producing a liquefied petroleum gas whose main component is propane or butane by circulating a synthesis gas in a slurry in which the catalyst according to any one of claims 1 to 8 is suspended in a solvent. A method for producing liquefied petroleum gas, comprising:

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