Method for producing liquefied petroleum gas, outlet gas, liquefied petroleum gas, and synthetic gas for producing liquefied petroleum gas

Abstract

Provided are: a method for producing a liquefied petroleum gas, the method being capable of improving a yield of the liquefied petroleum gas and a yield of propane; an outlet gas; a liquefied petroleum gas; and a synthetic gas for producing a liquefied petroleum gas. This method for producing a liquefied petroleum gas involves a liquefied petroleum gas production step in which a raw material gas containing a synthesis gas is supplied, and a liquefied petroleum gas is produced from the raw material gas. The hydrogen content in the raw material gas supplied in the liquefied petroleum gas production step is greater than the amount of hydrogen consumed in the liquefied petroleum gas production step.

Description

Method for producing liquefied petroleum gas, outlet gas, liquefied petroleum gas, and synthesis gas for producing liquefied petroleum gas.

[0001] This disclosure relates to a method for producing liquefied petroleum gas, an outlet gas, liquefied petroleum gas, and synthesis gas for producing liquefied petroleum gas.

[0002] Methods for producing liquefied petroleum gas from synthesis gas are known. For example, Patent Document 1 describes a method for producing liquefied petroleum gas from synthesis gas via methanol or dimethyl ether.

[0003] In conventional liquefied petroleum gas (LPG) production methods, the quantitative relationship between hydrogen and carbon monoxide in the synthesis gas is generally set to a chemical ratio or a value close to it, depending on the composition of the LPG being produced and the chemical reactions carried out in the production method.

[0004] However, using synthesis gas with such a composition results in low yields of both liquefied petroleum gas and propane, making it economically unviable. Furthermore, since propane is the main component of commonly available liquefied petroleum gas, there is a need to improve the propane yield in the liquefied petroleum gas.

[0005] International Publication No. 2008 / 015995

[0006] The purpose of this disclosure is to provide a method for producing liquefied petroleum gas, an outlet gas, liquefied petroleum gas, and a synthesis gas for producing liquefied petroleum gas that can improve the yield of liquefied petroleum gas and propane.

[0007] [1] A method for producing liquefied petroleum gas, comprising a liquefied petroleum gas production process in which a raw material gas containing synthesis gas is supplied and liquefied petroleum gas is produced from the raw material gas, wherein the hydrogen content in the raw material gas supplied to the liquefied petroleum gas production process is in excess of the amount of hydrogen consumed in the liquefied petroleum gas production process. [2] H of the outlet gas discharged from the liquefied petroleum gas production process ２ The method for producing liquefied petroleum gas as described in [1] above, wherein the CO ratio is 50.0 or higher. [3] H of the outlet gas discharged from the liquefied petroleum gas production process. ２A method for producing liquefied petroleum gas according to [1] or [2] above, wherein the H / CO ratio is 60.0 or more and 230.0 or less. [4] The H of the synthesis gas in the raw material gas supplied to the liquefied petroleum gas production process. ２ A method for producing liquefied petroleum gas according to any one of [1] to [3] above, wherein the CO ratio is 4.1 or more and 30.0 or less. [5] A method for producing liquefied petroleum gas according to any one of [1] to [4] above, further comprising a hydrogen recycling step of separating hydrogen from the outlet gas discharged from the liquefied petroleum gas production step and supplying the hydrogen recycled gas containing the hydrogen separated from the outlet gas to the liquefied petroleum gas production step. [6] A method for producing liquefied petroleum gas according to any one of [1] to [5] above, further comprising a separation step of separating liquefied petroleum gas from the outlet gas discharged from the liquefied petroleum gas production step. [7] A method for producing liquefied petroleum gas according to [5] above, wherein the ratio of the hydrogen content H2 in the outlet gas to the hydrogen content H1 in the hydrogen recycled gas is 50.0% or more and 100.0% or less. [8] A method for producing liquefied petroleum gas according to any one of [1] to [7] above, wherein the liquefied petroleum gas production step comprises only one fixed-bed reactor. [9] The method for producing liquefied petroleum gas according to [8], wherein the temperature downstream of the fixed-bed reactor is higher than the temperature upstream of the fixed-bed reactor.

[10] The method for producing liquefied petroleum gas according to any one of [1] to [7], wherein the liquefied petroleum gas production process comprises a first fixed-bed reactor and a second fixed-bed reactor, and the temperature inside the first fixed-bed reactor is lower than the temperature inside the second fixed-bed reactor.

[11] A raw material gas containing synthesis gas is supplied, and liquefied petroleum gas is produced from the raw material gas, and H ２ Outlet gas having a CO ratio of 60.0 or more and 230.0 or less.

[12] Liquefied petroleum gas separated from the outlet gas described in

[11] above.

[13] H ２ Synthetic gas for liquefied petroleum gas production with a CO ratio of 4.1 to 30.0.

[0008] According to this disclosure, it is possible to provide a method for producing liquefied petroleum gas, an outlet gas, liquefied petroleum gas, and synthesis gas for producing liquefied petroleum gas, which can improve the yield of liquefied petroleum gas and the yield of propane.

[0009] Figure 1 is a schematic diagram showing an example of a method for producing liquefied petroleum gas according to the embodiment. Figure 2 is a schematic diagram showing another example of a method for producing liquefied petroleum gas according to the embodiment.

[0010] The following will provide a detailed explanation based on the embodiments.

[0011] Liquefied petroleum gas (LPG) is a fuel primarily composed of propane and butane. Due to its high combustion efficiency, there is a demand for the production of LPG with a high propane content.

[0012] The present inventors have diligently researched methods for producing liquefied petroleum gas and have found that by setting the amount of hydrogen in the liquefied petroleum gas production process to be in excess of the amount of hydrogen consumed in the liquefied petroleum gas production process, the yield of liquefied petroleum gas and the yield of propane can be improved. Based on this finding, the present disclosure has been completed.

[0013] The embodiment of the method for producing liquefied petroleum gas includes a liquefied petroleum gas production process in which a raw material gas containing synthesis gas is supplied and liquefied petroleum gas is produced from the raw material gas, and the hydrogen content in the raw material gas supplied to the liquefied petroleum gas production process is in excess of the amount of hydrogen consumed in the liquefied petroleum gas production process.

[0014] Figure 1 is a schematic diagram showing an example of a method for producing liquefied petroleum gas according to the embodiment. As shown in Figure 1, the method for producing liquefied petroleum gas according to the embodiment 1 has a liquefied petroleum gas production step 2.

[0015] In the liquefied petroleum gas manufacturing process 2, raw material gas containing synthesis gas is supplied. Synthesis gas is hydrogen (H ２ It is a mixed gas of ) and carbon monoxide (CO).

[0016] The raw material gas mainly contains synthesis gas, and the synthesis gas concentration in the raw material gas is preferably 70% or more, more preferably 80% or more, even more preferably 90% or more, and particularly preferably 100%, that is, the raw material gas consists solely of synthesis gas.

[0017] The raw material gas may contain components other than synthesis gas, such as carbon dioxide, methane, ethane, and impurities in synthesis gas production (such as nitrogen). The concentration of components other than synthesis gas in the raw material gas is preferably 30% or less, more preferably 20% or less, even more preferably 10% or less, and particularly preferably 0%, meaning that the raw material gas does not contain components other than synthesis gas.

[0018] Liquefied petroleum gas (LPG) production process 2 produces LPG from raw material gas. Specifically, a methanol synthesis catalyst and a zeolite catalyst are used to produce LPG from hydrogen and carbon monoxide contained in the raw material gas.

[0019] The liquefied petroleum gas production process 2 includes, for example, a first fixed-bed reactor 21 and a second fixed-bed reactor 22, as shown in Figure 1.

[0020] The first fixed-bed reactor 21 contains a methanol synthesis catalyst and a zeolite catalyst (not shown). When a raw material gas is supplied to the first fixed-bed reactor 21, which is heated to a predetermined temperature, or when a raw material gas heated to a predetermined temperature is supplied to the first fixed-bed reactor 21, methanol is synthesized from carbon monoxide and hydrogen by the methanol synthesis catalyst, and then dimethyl ether is synthesized from methanol by the zeolite catalyst. The temperature inside the first fixed-bed reactor 21 is lower than the temperature inside the second fixed-bed reactor 22. The inside of the first fixed-bed reactor 21 is heated to, for example, 200°C to 460°C. The heating temperature is preferably 200°C to 350°C, more preferably 250°C to 320°C, and most preferably around 260°C (250°C to 270°C).

[0021] Furthermore, if the gas space velocity (GHSV) in the first fixed-bed reactor 21 is between 100 / h and 20,000 / h, dimethyl ether can be efficiently synthesized from carbon monoxide and hydrogen.

[0022] Furthermore, if the pressure inside the first fixed-bed reactor 21 is 1 MPa or more and 10 MPa or less, preferably 1 MPa or more and 5 MPa or less, then dimethyl ether can be efficiently synthesized from carbon monoxide and hydrogen.

[0023] A Cu-Zn-based catalyst is preferred as the methanol synthesis catalyst. The Cu-Zn-based catalyst contains copper or copper oxide and zinc or zinc oxide as its main components, and further contains aluminum oxide and zirconium oxide to improve the CO conversion rate, thereby enabling efficient production of methanol from carbon monoxide and hydrogen. The Cu-Zn-based catalyst is more preferably one that contains copper oxide, zinc oxide, and aluminum oxide.

[0024] Furthermore, the Cu-Zn catalyst may also contain gallium oxide or indium oxide. When these substances are included in the Cu-Zn catalyst, the dispersibility of copper oxide and zinc oxide is improved.

[0025] Furthermore, the Cu-Zn catalyst is preferably in the form of a powder or molded body. The Cu-Zn catalyst can be in the form of a powder (for example, a powder with a particle size of 10). －９ ~10 －４ It can be in the form of m. or granules with a larger particle size than powder, but if it is a molded body containing a Cu-Zn-based catalyst, the CO conversion rate can be further improved.

[0026] Regarding molded articles containing a Cu-Zn catalyst, the content of the Cu-Zn catalyst in the molded article is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. When the above content is 80% by mass or more, methanol can be efficiently synthesized from carbon monoxide and hydrogen. Note that the content of the Cu-Zn catalyst in the molded article may be 100% by mass, i.e., the molded article may be composed only of the Cu-Zn catalyst. Furthermore, the above content is preferably 98% by mass or less, more preferably 96% by mass or less, and even more preferably 94% by mass or less. When the above content is 98% by mass or less, the moldability and mechanical strength of the molded article can be improved while maintaining the efficient synthesis of methanol from carbon monoxide and hydrogen.

[0027] A molded article containing a Cu-Zn catalyst may also contain various additives to improve moldability and mechanical strength. Examples of such additives include molding binders such as graphite and carbon black.

[0028] As methanol synthesis catalysts, Cu-Cr catalysts mainly composed of copper or copper oxide and chromium or chromium oxide, or Cu-Zr catalysts mainly composed of copper or copper oxide and zirconium or zirconium oxide can also be used.

[0029] Zeolite catalysts are preferably those that support a precious metal. Because the zeolite constituting the zeolite catalyst has a zeolite skeleton, the zeolite catalyst has high water resistance and can suppress degradation caused by water produced as a by-product in methanol synthesis catalysts. Therefore, zeolite catalysts have excellent long-term stability and a long lifespan.

[0030] Furthermore, because the noble metal supported on the zeolite constituting the zeolite catalyst is Pt, the zeolite catalyst can efficiently convert methanol synthesized by the methanol synthesis catalyst into dimethyl ether. As a result, the yield of dimethyl ether in the first fixed-bed reactor 21 can be further improved, and the yield of liquefied petroleum gas in the subsequent second fixed-bed reactor 22 can be further improved.

[0031] The supported precious metals are preferably platinum group elements such as Pt, Pd, Rh, and Ru. There may be one or more types of precious metals. When there are two or more types of precious metals, the state in which the supported precious metals are supported is not particularly limited; for example, each precious metal may be present as a single metal, or as an alloy, or as a mixture of single metals and alloys.

[0032] The supported noble metal may be Pt alone, Pd alone, or a mixture of Pt and Pd. In particular, from the viewpoint of efficiently reacting with methanol, the noble metal may be Pt and Pd, and more preferably Pt alone. Regarding the state of the supported Pt and Pd, elemental Pt and elemental Pd may be mixed, Pt and Pd may be alloyed, or at least one of the elemental metals Pt and Pd may be mixed with an alloy of Pt and Pd.

[0033] Furthermore, the zeolite constituting the zeolite catalyst preferably contains P (phosphorus). That is, the zeolite catalyst preferably contains P. When a zeolite contains P, it is presumed that P bonds to O (oxygen) bonded to Si and O bonded to Al present on the surface of the zeolite (zeolite catalyst). As a result, the acid sites (solid acid sites) of the zeolite increase and change to weak acid sites, so the zeolite catalyst can further increase the yield of dimethyl ether.

[0034] With respect to the mass of P contained in the zeolite catalyst, relative to the mass of the zeolite catalyst, the lower limit is preferably more than 0% by mass, more preferably 0.5% by mass or more, still more preferably 1.0% by mass or more, and the upper limit is preferably less than 5.0% by mass, more preferably 4.0% by mass or less, still more preferably 3.0% by mass or less.

[0035] When the mass of the above P is more than 0% by mass relative to the mass of the zeolite catalyst, the yield of dimethyl ether can be further increased. In addition, when the mass of the above P is less than 5.0% by mass relative to the mass of the zeolite catalyst, for the zeolite having a porous structure, a decrease in the surface area of the zeolite caused by an increase in the P content can be suppressed, so dimethyl ether can be efficiently produced. Furthermore, liquefied petroleum gas can be efficiently produced.

[0036] Furthermore, the zeolite catalyst may contain Y (yttrium). When the zeolite catalyst contains Y, the generation of coke due to the synthesis of dimethyl ether can be suppressed. A zeolite catalyst with suppressed coke generation can sufficiently burn coke without requiring high-temperature regeneration treatment of the zeolite catalyst, so it can suppress agglomeration of methanol synthesis catalysts and noble metal particles, and can be used for a longer period of time.

[0037] Furthermore, the zeolite catalyst is preferably in the form of powder or granules, or a molded article. As the state of the zeolite catalyst, it may be powder or granules (powder, for example, having a particle diameter of 10 －９ to 10 －４It can be in the form of m. or granules with a larger particle size than powder, but if it is a molded body containing a zeolite catalyst, the yield of dimethyl ether can be further improved. Furthermore, liquefied petroleum gas can be produced efficiently.

[0038] Furthermore, while various known zeolites can be used as the zeolite constituting the zeolite catalyst, it is preferable that the zeolite be MFI-type zeolite, CHA-type zeolite, MEL-type zeolite, AEI-type zeolite, LEV-type zeolite, AFX-type zeolite, BEA-type zeolite, CON-type zeolite, TON-type zeolite, MWW-type zeolite, FAU-type zeolite, FER-type zeolite, ERI-type zeolite, or MOR-type zeolite. In particular, if the zeolite constituting the zeolite catalyst is MFI-type zeolite or CHA-type zeolite, the yield of dimethyl ether can be further improved. It is preferable that the MFI-type zeolite be ZSM-5. It is also preferable that the CHA-type zeolite be SSZ-13.

[0039] Furthermore, the zeolite constituting the zeolite catalyst can be replaced with various known porous materials. Examples include SAPO, ELAPO, ALPO, and alumina (Al ２ O ３ These are some examples. These porous materials also exhibit good water resistance.

[0040] Regarding the molded article containing the zeolite catalyst, the content of the zeolite catalyst in the molded article is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. When the above content is 70% by mass or more, dimethyl ether can be efficiently synthesized from methanol. Note that the content of the zeolite catalyst in the molded article may be 100% by mass, i.e., the molded article may be composed only of the zeolite catalyst. Furthermore, the above content is preferably 98% by mass or less, more preferably 96% by mass or less, and even more preferably 94% by mass or less. When the above content is 98% by mass or less, the moldability and mechanical strength of the molded article can be improved while maintaining the efficient synthesis of dimethyl ether from methanol. In addition, liquefied petroleum gas can be efficiently produced.

[0041] A molded article containing a zeolite catalyst may also contain various additives to improve moldability and mechanical strength. Examples of such additives include various clay binders, alumina-based binders, and silica-based binders. Preferred clay binders include kaolin-based, bentonite-based, talc-based, pyrophyllite-based, molysite-based, verculolite-based, montmorillonite-based, chlorite-based, and halloysite-based binders. A silica-based binder is preferred as the molding binder because it efficiently improves the catalytic activity of the zeolite catalyst and suppresses the formation of catalyst-poisoning substances such as coke.

[0042] When methanol synthesis catalysts and zeolite catalysts are molded bodies, the shape of these molded bodies is not particularly limited, and any desired shape such as cylindrical, cloverleaf, ring-shaped, spherical, or porous can be selected. In the case of cylindrical or cloverleaf shaped molded bodies, extruded products are preferred.

[0043] The particle size of the molded methanol synthesis catalyst and zeolite catalyst is preferably 200 μm or more, more preferably 300 μm or more, and preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less. A particle size of 200 μm or more prevents pressure loss in the reactor during synthesis. Furthermore, a particle size of 10 mm or less increases the contact efficiency between these catalysts and the reaction raw materials.

[0044] A zeolite catalyst (not shown) is housed inside the second fixed-bed reactor 22. When dimethyl ether synthesized in the first fixed-bed reactor 21 is supplied to the second fixed-bed reactor 22, which is heated to a predetermined temperature, or when dimethyl ether synthesized in the first fixed-bed reactor 21 and heated to a predetermined temperature is supplied to the second fixed-bed reactor 22, the zeolite catalyst decomposes and hydrogenates the dimethyl ether, thereby synthesizing liquefied petroleum gas. The temperature inside the second fixed-bed reactor 22 is higher than the temperature inside the first fixed-bed reactor 21. The inside of the second fixed-bed reactor 22 is heated to, for example, 200°C to 500°C. The heating temperature is preferably 320°C to 500°C, more preferably 350°C to 440°C, and most preferably 370°C to 420°C. In addition to dimethyl ether, the components introduced into the second fixed-bed reactor 22 may also include unreacted substances and by-products from the first fixed-bed reactor 21.

[0045] Furthermore, if the gas space velocity (GHSV) in the second fixed-bed reactor 22 is between 100 / h and 20,000 / h, liquefied petroleum gas can be efficiently synthesized from dimethyl ether.

[0046] Furthermore, if the pressure inside the second fixed-bed reactor 22 is 1 MPa or more and 10 MPa or less, preferably 1 MPa or more and 5 MPa or less, liquefied petroleum gas can be efficiently synthesized from carbon monoxide and hydrogen.

[0047] The zeolite catalyst housed inside the second fixed-bed reactor 22 may be the same as the zeolite catalyst housed inside the first fixed-bed reactor 21, or, if different, it can be selected from MFI type zeolite, CHA type zeolite, MEL type zeolite, AEI type zeolite, LEV type zeolite, AFX type zeolite, BEA type zeolite, CON type zeolite, TON type zeolite, MWW type zeolite, FAU type zeolite, FER type zeolite, ERI type zeolite, and MOR type zeolite. The MFI type zeolite is preferably ZSM-5. The CHA type zeolite is preferably SSZ-13.

[0048] When the zeolite catalyst in the second fixed-bed reactor 22 is the same as the zeolite catalyst in the first fixed-bed reactor 21, it is preferable that the zeolite catalyst in the first fixed-bed reactor 21 is ZSM-5 and the zeolite catalyst in the second fixed-bed reactor 22 is ZSM-5. Also, when the zeolite catalyst in the second fixed-bed reactor 22 is different from the zeolite catalyst in the first fixed-bed reactor 21, it is preferable that the zeolite catalyst in the first fixed-bed reactor 21 is ZSM-5 and the zeolite catalyst in the second fixed-bed reactor 22 is SSZ-13. When the zeolite catalyst is SSZ-13, the decomposition reaction of hydrocarbons with C5 or higher becomes dominant in the second fixed-bed reactor 22, and the yield of liquefied petroleum gas can be further improved. Also, SSZ-13 or ZSM-5 may have a noble metal such as Pt supported on it. Also, the SiO of the zeolite catalyst in the second fixed-bed reactor 22 ２ / Al ２ O ３ A smaller ratio results in a higher acid content in the zeolite catalyst, which can further improve the yields of both liquefied petroleum gas and propane.

[0049] SiO in the zeolite catalyst in the second fixed-bed reactor 22 ２ / Al ２ O ３ By controlling the ratio, preferably between 5 and 100, and more preferably between 5 and 50, the decomposition and hydrogenation reaction of dimethyl ether is promoted, further improving the yield of liquefied petroleum gas and propane.

[0050] Preferably, the acid content of the zeolite catalyst housed inside the second fixed-bed reactor 22 is greater than the acid content of the zeolite catalyst housed inside the first fixed-bed reactor 21. A suitable example is the SiO content of the zeolite catalyst housed inside the second fixed-bed reactor 22. ２ / Al ２ O ３ The ratio is 5 to 50, and the SiO of the zeolite catalyst housed inside the first fixed-bed reactor 21. ２ / Al ２ O ３ The ratio can be expressed as 5 or more and 100 or greater than 5 and 100 or less.

[0051] Furthermore, it is preferable that the methanol synthesis catalyst and the zeolite catalyst undergo hydrogen reduction treatment immediately before operation of the liquefied petroleum gas production method 1. Here, when a Cu-Zn-based catalyst is used as the methanol synthesis catalyst, it is preferable that the hydrogen reduction treatment reduces it to a methanol synthesis catalyst containing copper and zinc oxide.

[0052] In the liquefied petroleum gas (LPG) production method 1, the hydrogen content in the raw material gas supplied to the LPG production process 2 is in excess of the amount of hydrogen consumed in the LPG production process 2. By supplying the LPG production process 2 with a raw material gas containing an excess amount of hydrogen, the hydrogen content in the LPG production process 2 can be controlled to be in excess of the amount of hydrogen consumed in the LPG production process 2. The amount of hydrogen consumed in the LPG production process 2 refers to the amount of hydrogen consumed in the reaction that produces LPG from carbon monoxide and hydrogen in the LPG production process 2.

[0053] The inventors of the present invention conducted diligent research to improve the yield of liquefied petroleum gas in the liquefied petroleum gas manufacturing process 2, and found that the ratio of hydrogen to carbon monoxide supplied to the liquefied petroleum gas manufacturing process (H ２ We found that the CO ratio contributes to the yield of liquefied petroleum gas.

[0054] In the liquefied petroleum gas manufacturing method 1, whether the hydrogen content in the raw material gas supplied to the liquefied petroleum gas manufacturing process 2 is in excess of the amount of hydrogen consumed in the liquefied petroleum gas manufacturing process 2 can be determined by the hydrogen utilization rate, as described later.

[0055] In this way, by making the hydrogen content in the raw material gas supplied to the liquefied petroleum gas production process 2 exceed the amount of hydrogen consumed in the liquefied petroleum gas production process 2, the liquefied petroleum gas production method 1 can improve both the yield of liquefied petroleum gas and the yield of propane.

[0056] Furthermore, the liquefied petroleum gas produced in liquefied petroleum gas production process 2 is discharged from liquefied petroleum gas production process 2 as part of the outlet gas. The outlet gas is crude liquefied petroleum gas. In addition to liquefied petroleum gas, the outlet gas also contains hydrogen, carbon monoxide, carbon dioxide, and hydrocarbons other than liquefied petroleum gas. These gases other than liquefied petroleum gas are synthesis gas, impurities contained in the synthesis gas, unreacted materials from the liquefied petroleum gas production process, and by-reaction products from the liquefied petroleum gas production process.

[0057] Furthermore, the method for producing liquefied petroleum gas (LPG) 1 preferably further includes a separation step 3 for separating LPG from the outlet gas discharged from the LPG production step 2. By separating LPG from the outlet gas in the separation step 3, a gas with a high LPG concentration (high-concentration LPG) can be obtained. The obtained LPG has a high propane yield. In the separation step 3, preferably, carbon dioxide is separated from the outlet gas using a carbon dioxide separation membrane, followed by separation of hydrogen by the PSA (pressure swing adsorption) method, and then hydrocarbons other than LPG and other components are separated by distillation to obtain high-concentration LPG.

[0058] Furthermore, from the viewpoint of further improving the yield of liquefied petroleum gas and propane, the H content of the synthesis gas in the raw material gas supplied to the liquefied petroleum gas manufacturing process 2 is increased. ２ The H / CO ratio (molar ratio) is preferably 4.1 or higher. Furthermore, from the viewpoint of maintaining a high yield of liquefied petroleum gas and propane, the H of the synthesis gas in the raw material gas supplied to the liquefied petroleum gas manufacturing process 2 is also important. ２ The CO ratio is preferably 30.0 or less.

[0059] H of synthesis gas in the raw material gas supplied to the liquefied petroleum gas manufacturing process 2 ２A suitable lower limit for the CO ratio is, for example, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6. The values ​​are 9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, and 10.0.

[0060] H of synthesis gas in the raw material gas supplied to the liquefied petroleum gas manufacturing process 2 ２Suitable upper limits for the CO / CO ratio are, for example, 30.0, 29.9, 29.8, 29.7, 29.6, 29.5, 29.4, 29.3, 29.2, 29.1, 29.0, 28.9, 28.8, 28.7, 28.6, 28.5, 28.4, 28.3, 28.2, 28.1, 28.0, 27.9, 27.8, 27.7, 27.6, 27.5, 27.4, 27.3, 27.2, 27.1, 27.0, 26.9, 26.8, 26.7, 26.6, 26.5, 26.4, 26.3, 26.2, 26.1, 26.0, 25.9, 25.8, 25.7, 25.6, 25.5, 25.4 25.3, 25.2, 25.1, 25.0, 24.9, 24.8, 24.7, 24.6, 24.5, 24.4, 24.3, 24.2, 24.1, 24.0, 23.9, 23.8, 23.7, 23.6, 23.5, 23.4, 23.3, 23.2, 23.1, 23.0, 22.9 22.8, 22.7, 22.6, 22.5, 22.4, 22.3, 22.2, 22.1, 22.0, 21.9, 21.8, 21.7, 21.6, 21.5, 21.4, 21.3, 21.2, 21.1, 21.0, 20.9, 20.8, 20.7, 20.6, 20.5, 20.4 , 20.3, 20.2, 20.1, 20.0, 19.9, 19.8, 19.7, 19.6, 19.5, 19.4, 19.3, 19.2, 19.1, 19.0, 18.9, 18.8, 18.7, 18.6, 18.5, 18.4, 18.3, 18.2, 18.1, 18.0, 17.9 17.8, 17.7, 17.6, 17.5, 17.4, 17.3, 17.2, 17.1, 17.0, 16.9, 16.8, 16.7, 16.6, 16.5, 16.4, 16.3, 16.2, 16.1, 16.0, 15.9, 15.8, 15.7, 15.6, 15.5, 15.4 15.3, 15.2, 15.1, 15.0, 14.9, 14.8, 14.7, 14.6, 14.5, 14.4, 14.3, 14.2, 14.1, 14.0, 13.9, 13.8, 13.7, 13.6, 13.5, 13.4, 13.3, 13.2, 13.1, 13.0, 12.9 , 12.8, 12.7, 12.6, 12.5, 12.4, 12.3, 12.2, 12.1, 12.0, 11.9, 11.8, 11.7, 11.6, 11.5, 11.4, 11.3, 11.2, 11.1, 11.0, 10.9, 10.8, 10.7, 10.6, 10.5, 10.4,The values ​​are 10.3, 10.2, 10.1, 10.0, 9.9, 9.8, 9.7, 9.6, 9.5, 9.4, 9.3, 9.2, 9.1, and 9.0.

[0061] From the perspective of hydrogen utilization rate, the H of synthesis gas in the above-mentioned raw material gas ２ A CO ratio of 4.1 or higher is preferred. Hydrogen utilization rate refers to the ratio of hydrogen consumption to the hydrogen content in the raw material gas. ２ If the CO ratio is 4.1 or higher, the hydrogen utilization rate will be less than approximately 50%. A hydrogen utilization rate of less than approximately 50% means that the hydrogen content in the raw material gas supplied to the liquefied petroleum gas production process 2 is in excess of the amount of hydrogen consumed in the liquefied petroleum gas production process 2, that is, an excess of hydrogen has been supplied. The hydrogen utilization rate is preferably 50% or less, more preferably 40% or less, and particularly preferably 30% or less.

[0062] H of synthesis gas in the above raw material gas ２ The CO ratio can be 16.0 or less. ２ When the CO / H ratio exceeds 16.0, the hydrogen utilization rate falls below 20%. In this case, although the LPG yield is good because hydrogen is supplied in excess, it becomes difficult to balance the high cost of hydrogen consumption with the LPG yield. ２ By keeping the CO ratio below 16.0, it is possible to balance hydrogen usage with LPG yield. For the same reason, a hydrogen usage rate of 20% or more is preferable, and 22% or more is more preferable.

[0063] Furthermore, the LPG yield is improved, and the H content of the synthesis gas in the above-mentioned raw material gas is reduced. ２ A CO ratio of 4.1 or higher is preferred. ２ When the CO ratio exceeds 7.0, the effect of improving LPG yield begins to saturate, H ２ When the CO ratio exceeds 10.0, the LPG yield becomes almost constant, therefore, ２ The upper limit of the CO ratio is preferably 10.0 or less.

[0064] Based on the above, the H of synthesis gas in the raw material gas supplied to the liquefied petroleum gas manufacturing process 2 ２The preferred range for the CO ratio can be, for example, 4.1 to 16.0, 5.0 to 10.0, 6.0 to 11.0, 7.1 to 12.0, 8.0 to 13.0, 9.0 to 14.0, or 10.0 to 15.0. The most preferred range can be greater than 7.0 and 10.0 or less.

[0065] H ２ The H / CO ratio can be calculated by gas chromatography. Specifically, using an Agilent Technologies 8890GC, the H present in a certain amount of gas can be measured. ２ It can be calculated by determining the volume ratio of CO.

[0066] Furthermore, the liquefied petroleum gas manufacturing method 1 preferably further includes a hydrogen recycling step 4, which separates hydrogen from the outlet gas discharged from the liquefied petroleum gas manufacturing step 2 and supplies the hydrogen recycled gas containing the hydrogen separated from the outlet gas to the liquefied petroleum gas manufacturing step 2. The hydrogen separated from the outlet gas may be supplied entirely to the liquefied petroleum gas manufacturing step 2, or only a portion of it may be supplied to the liquefied petroleum gas manufacturing step 2.

[0067] If the liquefied petroleum gas (LPG) manufacturing method 1 includes a hydrogen recycling process 4, the hydrogen supplied to the LPG manufacturing process 2 by the supply of raw material gas is effectively utilized in the LPG manufacturing process 2 through the hydrogen recycling process 4. Therefore, the amount of hydrogen supplied separately to the LPG manufacturing method 1 in addition to the raw material gas can be reduced. Alternatively, it becomes unnecessary to supply hydrogen separately to the LPG manufacturing method 1 in addition to the raw material gas. Or, in the LPG manufacturing method 1, it becomes unnecessary to add a shift reaction process that generates a shift reaction as a hydrogen supply to the LPG manufacturing process 2.

[0068] Hydrogen recycled gas may contain components other than hydrogen, such as carbon monoxide, carbon dioxide, and lower hydrocarbon components. The concentration of components other than hydrogen in the hydrogen recycled gas can be 10 mol% or less, 9 mol% or less, 8 mol% or less, 7 mol% or less, 6 mol% or less, 5 mol% or less, 4 mol% or less, 3 mol% or less, 2 mol% or less, 1 mol% or less, or 0 mol%.

[0069] Furthermore, from the viewpoint of controlling the amount of hydrogen in the liquefied petroleum gas production process 2 to be in excess of the amount of hydrogen consumed in the liquefied petroleum gas production process 2, the ratio of the hydrogen content H2 in the outlet gas discharged from the liquefied petroleum gas production process 2 to the hydrogen content H1 in the hydrogen recycled gas supplied to the liquefied petroleum gas production process 2 in the hydrogen recycling process 4 (H2 × 100 / H1) is preferably 50.0% or more, more preferably 60.0% or more, even more preferably 70.0% or more, and particularly preferably 80.0% or more. Also, from the viewpoint of maintaining a high yield of liquefied petroleum gas and a high yield of propane, the above ratio (H2 × 100 / H1) is preferably 100.0% or less, more preferably 90.0% or less, and even more preferably 82.6% or less.

[0070] The hydrogen content in the hydrogen recycling gas supplied to the liquefied petroleum gas manufacturing process 2 in the hydrogen recycling process 4 can be interpreted as the amount of hydrogen contained in the raw material gas.

[0071] Therefore, from the viewpoint of controlling the amount of hydrogen in the liquefied petroleum gas production process 2 to be in excess of the amount of hydrogen consumed in the liquefied petroleum gas production process 2, the ratio of the hydrogen content H2 in the outlet gas discharged from the liquefied petroleum gas production process 2 to the amount of hydrogen H1 contained in the raw material gas (H2 × 100 / H1) is preferably 50.0% or more, more preferably 60.0% or more, even more preferably 70.0% or more, and particularly preferably 80.0% or more. Furthermore, from the viewpoint of maintaining a high yield of liquefied petroleum gas and a high yield of propane, the above ratio (H2 × 100 / H1) is preferably 100.0% or less, more preferably 82.6% or less.

[0072] The hydrogen content in the hydrogen recycled gas supplied to the liquefied petroleum gas production process 2 in the hydrogen recycling process 4 can be interpreted as the hydrogen content contained in the raw material gas and the hydrogen recycled gas.

[0073] Therefore, from the viewpoint of controlling the amount of hydrogen in the liquefied petroleum gas production process 2 to be in excess of the amount of hydrogen consumed in the liquefied petroleum gas production process 2, the ratio of the hydrogen content H2 in the outlet gas discharged from the liquefied petroleum gas production process 2 to the hydrogen content H1 contained in the raw gas and hydrogen recycled gas (H2 × 100 / H1) is preferably 50.0% or more, more preferably 60.0% or more, even more preferably 70.0% or more, and particularly preferably 80.0% or more. Furthermore, from the viewpoint of maintaining a high yield of liquefied petroleum gas and a high yield of propane, the above ratio (H2 × 100 / H1) is preferably 100.0% or less, more preferably 82.6% or less.

[0074] Furthermore, from the perspective of efficiently recycling hydrogen in the liquefied petroleum gas manufacturing method 1, the H of the outlet gas discharged from the liquefied petroleum gas manufacturing process 2 ２ The H / CO ratio should be 50.0 or higher, preferably 60.0 or higher, more preferably 70.0 or higher, even more preferably 75.0 or higher, and particularly preferably 80.0 or higher. Furthermore, from the viewpoint of maintaining high yields of liquefied petroleum gas and propane, the H of the outlet gas ２ The CO ratio is preferably 230.0 or less, more preferably 200.0 or less, and even more preferably 150.0 or less.

[0075] The hydrogen recycling described above can be described as resupplying most of the hydrogen recovered from crude liquefied petroleum gas (LPG) to the LPG manufacturing process. Alternatively, it can be described as circulating hydrogen within the LPG manufacturing process.

[0076] Furthermore, synthesis gas is preferably synthesized from biogas. Biogas contains carbon dioxide and hydrocarbons, including at least methane. Biogas is a renewable energy resource produced from organic waste such as livestock manure, food waste, and wood waste, and is environmentally friendly. Thus, in addition to being a renewable energy resource, biogas is easier to produce or obtain than natural resources such as natural gas. Therefore, using biogas as a raw material for synthesis gas allows for a stable supply of raw materials.

[0077] Furthermore, synthesis gas is preferably synthesized by a gas reforming reaction involving an oxidizing agent and a hydrocarbon containing at least methane. For example, carbon dioxide, steam, or oxygen can be used as the oxidizing agent. Depending on the type of oxidizing agent and the ratio of the oxidizing agent to the hydrocarbon, the above H ２ It is known that the CO ratio can be varied. Therefore, as one means of controlling the amount of hydrogen in the liquefied petroleum gas production process 2 to be in excess of the amount of hydrogen consumed in the liquefied petroleum gas production process 2, it is preferable to select the type of oxidizer and the ratio of the oxidizer to the hydrocarbon. The oxidizer preferably contains carbon dioxide. It is also preferable that the oxidizer contains carbon dioxide and steam.

[0078] Furthermore, other components may be included in the biogas or the oxidizing agent and hydrocarbon. Preferably, the other components are compounds containing hydrogen atoms, such as NH. ３ More preferable. The oxidizing agent oxidizes the compound containing a hydrogen atom and H ２ By generating this, the amount of hydrogen in the liquefied petroleum gas production process 2 can be controlled to be in excess of the amount of hydrogen consumed in the liquefied petroleum gas production process 2.

[0079] Figure 2 is a schematic diagram showing another example of the method for producing liquefied petroleum gas according to the embodiment. In the method for producing liquefied petroleum gas 1, the liquefied petroleum gas production process 2 includes only one fixed-bed reactor 20. Figure 1 shows an example in which the liquefied petroleum gas production process 2 includes multiple fixed-bed reactors, namely a first fixed-bed reactor 21 and a second fixed-bed reactor 22. However, as shown in Figure 2, by providing a single fixed-bed reactor instead of multiple fixed-bed reactors in the liquefied petroleum gas production process 2, the yield of liquefied petroleum gas and the yield of propane can be further improved.

[0080] In this case, from the viewpoint of improving the yield of liquefied petroleum gas and propane, it is preferable to house the methanol synthesis catalyst and the zeolite catalyst on the upstream side of the fixed-bed reactor 20, and the zeolite catalyst on the downstream side of the fixed-bed reactor 20. The zeolite catalyst housed on the upstream side of the fixed-bed reactor 20 and the zeolite catalyst housed on the downstream side of the fixed-bed reactor 20 may be the same zeolite catalyst or different zeolite catalysts. Here, the upstream side refers to the side in the fixed-bed reactor 20 from which the raw material gas is fed, and the downstream side refers to the side in the fixed-bed reactor 20 from which the outlet gas is discharged. It is preferable that the upstream and downstream sides are separated by a mesh to suppress mixing of the methanol synthesis catalyst and the zeolite catalyst within the fixed-bed reactor 20. In addition, inert balls that do not contribute to the reaction may be packed between the upstream and downstream sides. In addition, a space may be provided between the upstream and downstream sides. Upstream: The bulk density of the catalyst packing on the downstream side can be set to 1:10 to 10:1.

[0081] It is preferable to control the temperature on the upstream side of the fixed-bed reactor 20 in the same way as the first fixed-bed reactor 21, and the temperature on the downstream side of the fixed-bed reactor 20 in the same way as the second fixed-bed reactor 22. Therefore, the upstream side of the fixed-bed reactor 20 is heated to 200°C or higher and 460°C or lower. The heating temperature is preferably 200°C or higher and 350°C or lower, more preferably 250°C or higher and 320°C or lower, and most preferably around 260°C (250°C or higher and 270°C or lower). Also, the downstream side of the fixed-bed reactor 20 is heated to 200°C or higher and 460°C or lower. The heating temperature is preferably 320°C or higher and 450°C or lower, more preferably 350°C or higher and 430°C or lower, and most preferably 370°C or higher and 420°C or lower. It is preferable to control the temperature on the downstream side of the fixed-bed reactor 20 to be higher than the temperature on the upstream side of the fixed-bed reactor 20.

[0082] It is preferable to control the gas space velocity upstream of the fixed-bed reactor 20 in the same manner as the first fixed-bed reactor 21, and the gas space velocity downstream of the fixed-bed reactor 20 in the same manner as the second fixed-bed reactor 22. In other words, it is preferable to control the gas space velocity upstream of the fixed-bed reactor 20 to 100 / h or more and 20,000 / h or less, and the gas space velocity downstream of the fixed-bed reactor 20 to 100 / h or more and 20,000 / h or less. That is, it is preferable to control the gas space velocity conditions upstream of the fixed-bed reactor 20 to the same conditions as the first fixed-bed reactor 21, and the gas space velocity conditions downstream of the fixed-bed reactor 20 to the same conditions as the second fixed-bed reactor 22.

[0083] It is preferable to control the pressure upstream of the fixed-bed reactor 20 in the same manner as the first fixed-bed reactor 21, and the pressure downstream of the fixed-bed reactor 20 in the same manner as the second fixed-bed reactor 22. In other words, it is preferable to control the pressure upstream of the fixed-bed reactor 20 to 1 MPa or more and 10 MPa or less, preferably 1 MPa or more and 5 MPa or less, and the pressure downstream of the fixed-bed reactor 20 to 1 MPa or more and 10 MPa or less, preferably 1 MPa or more and 5 MPa or less. That is, it is preferable to control the pressure conditions upstream of the fixed-bed reactor 20 to the same conditions as the first fixed-bed reactor 21, and the pressure conditions downstream of the fixed-bed reactor 20 to the same conditions as the second fixed-bed reactor 22.

[0084] Furthermore, as shown in Figure 2, when only one fixed-bed reactor 20 is provided, it is preferable that the upstream zeolite catalyst has a lower acid content than the downstream zeolite catalyst. In this case, the SiO of the upstream zeolite catalyst with a lower acid content is preferable. ２ / Al ２ O ３ The ratio should be between 5 and 100, with a higher acid content in the downstream zeolite catalyst. ２ / Al ２ O ３ The ratio can be set to 5 or more and 50 or more than 5 and 100 or less.

[0085] Next, the outlet gas of the embodiment will be described.

[0086] The outlet gas (crude liquefied petroleum gas) of the embodiment is discharged from a liquefied petroleum gas production process in which raw material gas containing synthesis gas is supplied and liquefied petroleum gas is produced from the raw material gas, H ２ The CO ratio is 50.0 or higher, preferably 60.0 to 230.0. The liquefied petroleum gas manufacturing process is preferably the liquefied petroleum gas manufacturing process 2 in the liquefied petroleum gas manufacturing method 1 of the above embodiment.

[0087] H of the outlet gas ２ When the CO / CO ratio is 50.0 or higher, preferably 60.0 or higher, hydrogen can be separated from the outlet gas, and by supplying the hydrogen recycled gas containing the hydrogen separated from the outlet gas to the liquefied petroleum gas production process, the yield of liquefied petroleum gas and the yield of propane can be improved. Therefore, the H of the outlet gas ２ The CO ratio is 50.0 or higher, preferably 60.0 or higher, more preferably 70.0 or higher, and even more preferably 80.0 or higher.

[0088] Also, the H of the outlet gas ２ If the CO / CO ratio is 230.0 or less, high yields of liquefied petroleum gas and propane can be maintained. Therefore, the H of the outlet gas ２ The CO ratio is 230.0 or less, preferably 200.0 or less, and more preferably 150.0 or less.

[0089] Furthermore, the liquefied petroleum gas separated from these outlet gases has a high propane yield.

[0090] Next, we will describe the synthesis gas for liquefied petroleum gas production according to the embodiment.

[0091] The synthesis gas for liquefied petroleum gas production in this embodiment is H ２ The CO ratio is 4.1 or higher and 30.0 or lower. The synthesis gas for liquefied petroleum gas production is preferably the synthesis gas used in the liquefied petroleum gas production method 1 of the above embodiment.

[0092] H ２ Using synthesis gas for liquefied petroleum gas production with a CO / CO ratio of 4.1 or higher as a raw material can improve the yield of both liquefied petroleum gas and propane. Therefore, the H of the synthesis gas for liquefied petroleum gas production ２The CO ratio is 4.1 or higher, preferably 5.0 or higher, more preferably 6.0 or higher, and even more preferably 7.0 or higher.

[0093] Also, H ２ When synthesis gas for liquefied petroleum gas production with a CO / CO ratio of 30.0 or less is used as a raw material, high yields of liquefied petroleum gas and propane can be maintained. Therefore, the H of synthesis gas for liquefied petroleum gas production ２ The CO ratio is 30.0 or less, preferably 25.0 or less, and more preferably 20.0 or less.

[0094] According to the embodiments described above, by setting the amount of hydrogen in the liquefied petroleum gas production process to be in excess of the amount of hydrogen consumed in the liquefied petroleum gas production process, it is possible to improve the yield of liquefied petroleum gas and the yield of propane in the method of producing liquefied petroleum gas.

[0095] The liquefied petroleum gas produced in the embodiments described above has a propane content of 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more.

[0096] Although embodiments have been described above, the present invention is not limited to the embodiments described above, and includes all aspects included in the concepts and claims of this disclosure, and can be modified in various ways within the scope of this disclosure.

[0097] Examples and comparative examples will be described next, but this disclosure is not limited to these examples.

[0098] (Cu-Zn catalyst) A Cu-Zn catalyst, a ternary oxide of copper oxide, zinc oxide, and aluminum oxide (product name: 45776 Copper-based methanol synthesis catalyst, manufactured by Alpha Acer), was used as the methanol synthesis catalyst. This Cu-Zn catalyst was crushed in an agate mortar and sieved using a combination of a 300 μm mesh and a 500 μm mesh. This yielded molded bodies consisting of granular methanol synthesis catalyst with particle sizes of 300 to 500 μm.

[0099] (Zeolite catalyst (SiO２ / Al ２ O ３ = 33 MFI-type zeolite)) MFI-type zeolite (ZSM-5, SiO ２ / Al ２ O ３ =33) was formed into pellets with a diameter of 20 mm and a thickness of approximately 1 mm using a tablet molder. These pellets were then crushed in a mortar, and the crushed sample was sieved using a combination of a 300 μm mesh and a 500 μm mesh. As a result, the sample was found to have a particle size of 300-500 μm, be granular, and have a bulk density of 0.7 g / cm³. ３ SiO ２ / Al ２ O ３ A molded body consisting of 33 MFI-type zeolite (zeolite catalyst) was obtained.

[0100] (Zeolite catalyst (SiO ２ / Al ２ O ３ = 100 MFI-type zeolite)) MFI-type zeolite (ZSM-5, SiO ２ / Al ２ O ３ Except for using (=100), the same procedure was followed, SiO ２ / Al ２ O ３ A molded body consisting of MFI-type zeolite (zeolite catalyst) with a concentration of 100 was obtained.

[0101] (Zeolite catalyst (SSZ-13)) SSZ-13 (manufactured by ACS MATERIAL, CAS-No.: 1318-02-1) was formed into pellets with a diameter of 20 mm and a thickness of approximately 1 mm using a tablet press. These pellets were then crushed in a mortar, and the crushed sample was sieved using a combination of a 300 μm mesh and a 500 μm mesh. As a result, a granular material with a particle size of 300-500 μm and a bulk density of 0.6 g / cm³ was obtained. ３ A molded body made of SSZ-13 (zeolite catalyst) was obtained.

[0102] (Zeolite catalyst (Pt-supported SSZ-13)) 5 g of SSZ-13 (manufactured by ACS Materials, CAS No.: 1318-02-1) was put into an agate mortar, and an aqueous solution prepared by dissolving 0.0667 g of chloroplatinic acid hexahydrate in 4.5 g of 10% hydrochloric acid was added dropwise thereto with a pipette while mixing uniformly with a pestle. After impregnation for about 1 hour, the mixture was dried at 100°C for 10 hours, heated from room temperature to 500°C in 50 minutes under an air atmosphere, and calcined at the same temperature for 120 minutes, thereby obtaining Pt-supported SSZ-13. Subsequently, this zeolite was formed into pellets with a diameter of 20 mm and a thickness of about 1 mm using a tablet press, and after crushing the pellets in a mortar, the crushed sample was sieved using a 300 μm mesh and a 500 μm mesh stacked together. Thereby, a molded body made of SSZ-13 (zeolite catalyst) supporting granular Pt with a particle size of 300 to 500 μm was obtained.

[0103] (Examples 1 to 3, Comparative Example 1, Reference Examples 1 to 2, 5) A molded body made of a Cu-Zn based catalyst and SiO ２ / Al ２ O ３ =100 molded bodies made of MFI-type zeolite were mixed, and filled as a front-stage catalyst into a first fixed-bed reactor. A molded body made of SSZ-13 (zeolite catalyst) was filled into a second fixed-bed reactor.

[0104] Using the raw material gases shown in Table 1, liquefied petroleum gas was produced under the conditions shown in Table 1 by the method for producing liquefied petroleum gas having the configuration shown in Figure 1 and Table 1.

[0105] (Examples 4 to 5, Comparative Example 2, Reference Examples 3, 4) A molded body made of a Cu-Zn based catalyst and SiO ２ / Al ２ O ３ =100 molded bodies made of MFI-type zeolite were mixed, and filled as a front-stage catalyst into a first fixed-bed reactor. A molded body made of MFI-type zeolite having a SiO ２ / Al ２ O ３ ratio shown in Table 3 was filled into a second fixed-bed reactor.

[0106] Using the raw material gases shown in Table 3, liquefied petroleum gas was produced under the conditions shown in Table 3 by the method for producing liquefied petroleum gas having the configuration shown in Figure 1 and Table 3.

[0107] (Example 6) A molded body composed of a Cu-Zn-based catalyst and SiO ２ / Al ２ O ３ = 100 MFI-type zeolite molded bodies were mixed and filled into a first fixed-bed reactor as a front-stage catalyst. A molded body composed of Pt-supported SSZ-13 was filled into a second fixed-bed reactor.

[0108] Using the raw material gases shown in Table 2, liquefied petroleum gas was produced under the conditions shown in Table 2 by the method for producing liquefied petroleum gas having the configuration shown in Figure 1 and Table 2.

[0109] (Example 7) As shown in Table 3, SiO in the rear-stage catalyst ２ / Al ２ O ３ Liquefied petroleum gas was produced in the same manner as in Example 4, except that the ratio was changed to MFI-type zeolite with a ratio of 100.

[0110] (Example 8) A molded body composed of a Cu-Zn-based catalyst and SiO ２ / Al ２ O ３ = 100 MFI-type zeolite molded bodies were mixed and filled into the upper stage of a fixed-bed reactor as a front-stage catalyst. A molded body composed of SSZ-13 was filled into the lower stage of the fixed-bed reactor.

[0111] Using the raw material gases shown in Table 1, liquefied petroleum gas was produced under the conditions shown in Table 1 by the method for producing liquefied petroleum gas having the configuration shown in Figure 2 and Table 1.

[0112] (Examples 10 to 12) A molded body composed of a Cu-Zn-based catalyst and SiO ２ / Al ２ O ３ = 100 MFI-type zeolite molded bodies were mixed and filled into a first fixed-bed reactor as a front-stage catalyst. SiO ２ / Al ２ O ３ = 33 MFI-type zeolite molded body was filled into a second fixed-bed reactor.

[0113] Liquefied petroleum gas was produced using the raw material gases shown in Table 4 and the liquefied petroleum gas production method having the configuration shown in Figure 1 and Table 4, under the conditions shown in Table 4.

[0114] The outlet gas produced in the above examples and comparative examples, and the liquefied petroleum gas separated from the outlet gas, were analyzed. The results are shown in Tables 1 to 4. In Tables 1 to 4, the LPG yield ratio was calculated using the same upstream and downstream catalysts, with H ２ The LPG yield was calculated based on the LPG yield of reference examples with a CO / CO ratio of 6.0 (specifically, Reference Example 2 in Examples 1-3, 8, Comparative Example 1, Reference Examples 1-2, and 5 shown in Table 1, and Reference Example 4 in Examples 4-5, 7, 10-12, Comparative Example 2, and Reference Examples 3-4 shown in Tables 3-4). Furthermore, the ranking of the LPG yield ratio evaluation was based on using the same upstream and downstream catalysts, with H ２ For the LPG yield in the reference example with a CO-to-O ratio of 6.0, cases less than 1.00 times were marked with ×, cases between 1.00 times and 1.25 times were marked with ○, and cases of 1.25 times or more were marked with ◎.

[0115] Furthermore, the hydrogen utilization rate was calculated using the hydrogen consumption and hydrogen flow rate in the raw gas shown in each table. The hydrogen utilization rate was ranked as follows: × for a rate exceeding 50.0%, ○ for a rate less than 20.0%, and ◎ for a rate between 20.0% and 50.0%.

[0116] The LPG yield was calculated using the following formula: LPG yield (Cmol%) = Propane yield (Cmol%) + Butane yield (Cmol%) Propane yield (Cmol%) = [(C3 generation rate) / (CO flow rate in raw material gas) × 10 ６ [ / 22400] × 100 The unit of the C3 production rate is C μmol / min, and the unit of the CO flow rate in the raw material gas is ml (Normal) / min. C3 is propane. Butane yield (C mol%) = [(C4 production rate) / (CO flow rate in raw material gas) × 10 ６ [ / 22400] × 100 The unit of the C4 production rate is C μmol / min, and the unit of the CO flow rate in the raw material gas is ml (Normal) / min. C4 is butane.

[0117] The hydrogen usage rate was calculated using the following formula: Hydrogen usage rate (%) = Hydrogen consumption (N ml / min) × 100 / Hydrogen flow rate in raw gas (N ml / min) Hydrogen consumption (N ml / min) = Hydrogen flow rate of raw gas (N ml / min) - Hydrogen flow rate of outlet gas (N ml / min)

[0118] The CO conversion rate was calculated using the following formula: CO conversion rate (%) = [(CO flow rate in raw material gas (μmol / min) - CO flow rate in outlet gas (μmol / min)) / CO flow rate in raw material gas (μmol / min)] × 100 The CO conversion rate indicates the proportion of carbon monoxide (CO) in the raw material gas that was converted to hydrocarbons, etc.

[0119]

[0120]

[0121]

[0122] As shown in Tables 1 to 4, in the above embodiment, the hydrogen content in the raw material gas supplied to the liquefied petroleum gas (LPG) production process was in excess of the hydrogen consumption in the LPG production process, thus improving the yield of LPG and the yield of propane. In other words, since the evaluation of the hydrogen utilization rate was ○ or ◎, the hydrogen content in the raw material gas supplied to the LPG production process was in excess of the hydrogen consumption in the LPG production process, thus improving the yield of LPG and the yield of propane. On the other hand, in the above comparative example, the hydrogen content in the raw material gas supplied to the LPG production process was not in excess of the hydrogen consumption in the LPG production process, so it was not possible to improve at least one of the yields of LPG and propane.

[0123] Furthermore, as shown in Table 4, Examples 10 to 12 were able to maintain a low hydrogen utilization rate and improve LPG yield even when the downstream temperature was changed to 350 to 440°C.

[0124] 1. Method for producing liquefied petroleum gas 2. Liquefied petroleum gas production process 20. Fixed bed reactor 21. First fixed bed reactor 22. Second fixed bed reactor 3. Separation process 4. Hydrogen recycling process

Claims

1. A method for producing liquefied petroleum gas, comprising a liquefied petroleum gas production process in which a raw material gas containing synthesis gas is supplied and liquefied petroleum gas is produced from the raw material gas, wherein the hydrogen content in the raw material gas supplied to the liquefied petroleum gas production process is in excess of the amount of hydrogen consumed in the liquefied petroleum gas production process.

2. H of the outlet gas discharged from the liquefied petroleum gas manufacturing process. ２ A method for producing liquefied petroleum gas according to claim 1, wherein the CO ratio is 50.0 or higher.

3. H of the outlet gas discharged from the liquefied petroleum gas manufacturing process. ２ A method for producing liquefied petroleum gas according to claim 1, wherein the CO ratio is 60.0 or more and 230.0 or less.

4. The H of the synthesis gas in the raw material gas supplied to the liquefied petroleum gas manufacturing process. ２ A method for producing liquefied petroleum gas according to claim 1, wherein the CO ratio is 4.1 or more and 30.0 or less.

5. A method for producing liquefied petroleum gas according to any one of claims 1 to 4, further comprising a hydrogen recycling step of separating hydrogen from the outlet gas discharged from the liquefied petroleum gas production step and supplying the hydrogen recycled gas containing the hydrogen separated from the outlet gas to the liquefied petroleum gas production step.

6. A method for producing liquefied petroleum gas according to any one of claims 1 to 4, further comprising a separation step for separating liquefied petroleum gas from the outlet gas discharged from the liquefied petroleum gas production step.

7. The method for producing liquefied petroleum gas according to claim 5, wherein the ratio of the hydrogen content H2 in the outlet gas to the hydrogen content H1 in the hydrogen recycled gas is 50.0% or more and 100.0% or less.

8. The method for producing liquefied petroleum gas according to any one of claims 1 to 4, wherein the liquefied petroleum gas production process comprises only one fixed-bed reactor.

9. The method for producing liquefied petroleum gas according to claim 8, wherein the temperature on the downstream side of the fixed-bed reactor is higher than the temperature on the upstream side of the fixed-bed reactor.

10. The method for producing liquefied petroleum gas according to claim 1, wherein the liquefied petroleum gas production process comprises a first fixed-bed reactor and a second fixed-bed reactor, and the temperature inside the first fixed-bed reactor is lower than the temperature inside the second fixed-bed reactor.

11. A raw material gas containing synthesis gas is supplied, and liquefied petroleum gas is produced from the raw material gas in a liquefied petroleum gas production process, and H ２ Outlet gas with a CO ratio of 60.0 to 230.

0.

12. Liquefied petroleum gas separated from the outlet gas according to claim 11.

13. H ２ Synthetic gas for liquefied petroleum gas production with a CO ratio of 4.1 to 30.0.

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