JP4776287B2 - Clean gasoline composition and method for producing the same - Google Patents

Description

  The present invention relates to a gasoline composition and a method for producing the same in consideration of environmental impact while ensuring sufficient operating characteristics.

  In recent years, with the expansion of global industrial economic activity scale, the destruction of the environment at the global level has become a serious problem, and countermeasures for this are beginning to be studied worldwide. Above all, there is concern that the global warming problem will have a significant adverse effect not only on humanity but also on the earth itself. Therefore, in order to prevent the emission of gases that cause global warming (greenhouse gases: carbon dioxide, methane, dinitrogen monoxide, hydrofluorocarbon, perfluorocarbon, and sulfur hexafluoride) into the atmosphere, There is a strong demand for the establishment of countermeasures. The Kyoto Protocol entered into force in February 2005, and Japan is obliged to reduce greenhouse gas emissions by 6 percent compared to the 1990 level.

  Considering the aspect of automobile fuel, the demand for high-performance gasoline having high driving performance is increasing as the performance of automobiles increases. In particular, it is said that the higher the octane number (RON) of the research method, the better the driving performance of the car, the higher the energy conversion efficiency, and the reduction of carbon dioxide emissions, which is considered one of the global warming gases. ing. On the other hand, environmental pollution due to automobile fuel itself and its combustion exhaust gas has become a social problem, and automobile fuel that maintains high driving performance and has a low environmental impact is desired. In particular, from the viewpoint of exhaust gas purification, further reduction of the sulfur content is also desired.

  JIS K 2202 stipulates No. 1 automobile gasoline with RON of 96.0 or more and No. 2 automobile gasoline with 89.0 or more. The former is marketed as high-performance premium gasoline and the latter as regular gasoline. Yes. Conventionally, premium gasoline is mainly based on base materials having 100 or more RONs such as catalytic reformed gasoline base materials, alkylate gasoline base materials, and base materials having 93 or more RONs such as light components of catalytic cracked gasoline. Manufactured by blending various base materials. On the other hand, regular gasoline is produced by blending an aroma fraction, a desulfurized straight-run naphtha having a low RON, etc. with a catalytic cracking gasoline base material as the center.

Conventionally, cracked gasoline fractions such as catalytically cracked gasoline and various cracked gasolines generally contain a large amount of olefins and aroma, greatly contributing to the improvement of RON. On the other hand, paraffins having a relatively low RON are not preferred as gasoline base materials, and have been reduced.
On the other hand, aroma compounds and olefin compounds that are widely used as compounds having high RON are unlikely to be used in the future in terms of the environment. Specifically, it is said that aroma compounds are carcinogenic and have problems with the PRTR method, and that when used as a fuel for automobiles, some of them are changed to particulate compounds (PM). Is photochemically unstable and has a problem in storage stability, so that it has been pointed out that a solid compound such as sludge is precipitated.

  Furthermore, although the fraction containing a large amount of aroma compound has the advantage of high RON, it has a high boiling point and cannot be contained in the gasoline base material from the viewpoint of distillation properties. In addition, the olefin component has a relatively high molecular weight but has a high RON, but the vapor pressure tends to be high, so that it cannot be used in many gasoline base materials. There is a tendency to require a substrate having a light distillation property, that is, a property having a relatively low boiling point and a low Reed vapor pressure (RVP).

  Taking the above situation into consideration and looking at the actual situation of gasoline production, cracked gasoline base materials produced by cracking heavy petroleum fractions are more economical to manufacture than other gasoline base materials. While it has the advantage of being able to do so, it contains a lot of sulfur. As a result, most of the sulfur content in the gasoline produced as described above is derived from the cracked gasoline base material. The sulfur content contained in the cracked gasoline base material can be easily reduced using a known technique of hydrotreating in the presence of high-pressure hydrogen and a catalyst. However, in that case, a large amount of catalytic cracking gasoline base material is contained, and the olefin component having high RON is hydrogenated to decrease the RON of the base material. There was a problem that it was difficult to obtain gasoline. Recently, a technique for suppressing hydrogenation of olefins and suppressing reduction of RON has also been developed (see Patent Document 1), but the above-described problem that olefins adversely affect the environment has not been solved. In addition, development of paraffinic gasoline with a sulfur content reduced to 50 ppm by mass has been reported (see Patent Document 2), but considering the performance as a common gasoline that can be used as a fuel for future fuel cells. However, there was no method for producing paraffinic gasoline having an appropriate distillation property and vapor pressure as a fuel for a gasoline engine and having a high RON at this sulfur level. .

  On the other hand, a technique is known that can improve RON, which is important as a gasoline base material, by skeletal isomerization of hydrocarbon oil under specific conditions. Isoparaffins produced by the skeletal isomerization reaction are effective as environmentally friendly clean fuels because they have little adverse effects on the environment such as aroma compounds and olefin compounds. Specifically, skeletal isomerization is a reaction that generally converts linear paraffin with a low RON to a branched paraffin with a high RON. Fischer-Tropsch (hereinafter referred to as “FT”) wax obtained by GTL (Gas To Liquid) technology using hydrogen or carbon monoxide generated from natural gas, steelworks, etc. as a raw material can be used.

  GTL oil is mainly obtained by a reaction that synthesizes a straight-chain saturated hydrocarbon, and has been reported to be applied to lubricating oil, light oil, and kerosene (see Patent Document 3), but is applied to gasoline. The technology has not yet been reported. As described above, RON is an important indicator for the properties of gasoline. However, high RON gasoline, that is, gasoline with less linear paraffin and increased branched paraffin is produced from GTL oil with much linear paraffin. This is considered to be difficult (see Patent Document 4). In other words, it is extremely difficult to satisfy a compound having a high ratio of hydrogen to carbon (paraffins) in hydrocarbons, high RON, and proper distillation properties, vapor pressure, and many other indicators as gasoline. . There is a possibility that it can be applied to gasoline bases by isomerizing linear paraffins, but the desired effect cannot be obtained unless an appropriate catalyst or process is used, and water is produced during FT synthesis. However, since moisture generally has an adverse effect on the hydrocracking / isomerization catalyst (see Patent Document 5), it has been necessary to remove the moisture and carry out the isomerization reaction.

As in the isomerization reaction, there is an alkylation reaction as a process capable of selectively producing isoparaffin. The alkylation reaction is a reaction in which an acid catalyst such as sulfuric acid is used to react mainly with an olefin having 4 carbon atoms and isoparaffin to produce an 8 carbon isoparaffin, and many apparatuses have already been operated all over the world. (See Non-Patent Document 1). However, because of the characteristics of the reaction, the product is mainly an isoparaffin having 8 carbon atoms, so that a multibranched isoparaffin having 8 carbon atoms can be obtained, but a multibranched isoparaffin having less than 8 carbon atoms is obtained. That was difficult. Alkylate gasoline is composed of high-boiling components, so it is restricted by distillation properties, and because it uses relatively expensive compounds with 4 carbon atoms as a raw material, it is subject to restrictions as a raw material. Could not be manufactured and used.
Due to the circumstances as described above, the gasoline composition that still has sufficient practical performance, such as being able to maintain satisfactory RON while sufficiently reducing the aroma content and olefin content, with a sulfur content as low as 1 ppm by mass or less. It has not been developed and its manufacturing method has not been established.
JP 2003-183676 A International Publication No. 2002/046334 JP-T-2004-500977 Special table 2003-524679 gazette JP 2000-169863 A Edited by Petroleum Society, “Petroleum Refining Process”, p209 ～ 216, Kodansha Scientific, 1998

  The present invention was made to solve the above-mentioned problems, and the present invention significantly reduces the load on the environment by reducing the amount of sulfur dioxide and carbon dioxide generated during combustion while ensuring sufficient operating characteristics. An object is to provide a gasoline composition.

  The inventors of the present invention have made extensive studies to solve the above-described problems, and without subjecting the reaction product, which is obtained by Fischer-Tropsch synthesis, to a sulfur-free reaction product to be subjected to hydrocracking / isomerization as it is. It has been found that the above gasoline base material can be obtained by contacting with a catalyst. The present invention has been conceived based on such knowledge.

  That is, the present invention provides a vapor pressure of 65 kPa, which includes AGTL gasoline obtained by contacting a mixed gas of carbon monoxide and hydrogen with a Fischer-Tropsch catalyst and a hydrocracking / isomerization catalyst, and alkylate gasoline. In the following, the research octane number is 91 or more, the sulfur content is 1 mass ppm or less, the silver plate corrosion is 1 or less, the 50 vol% distillation temperature of distillation properties is 95 ° C or less, the aroma content is 1 vol% or less, and the olefin content is 1 A clean gasoline composition having a volume% or less and a hydrogen / carbon ratio (mol) of 2.3 or more.

  The clean gasoline composition of the present invention may further contain an oxygen-containing compound, and is further selected from the group consisting of liquefied petroleum gas, isopentane, desulfurized straight naphtha, catalytic reformed gasoline, and desulfurized catalytic cracked gasoline. One or more gasoline base materials may be included. Moreover, the clean gasoline composition of the present invention can be suitably used as a fuel for gasoline engines or a fuel cell fuel.

Further, the present invention is a method for producing the clean gasoline composition,
(A) purifying a reaction product obtained by contacting a mixed gas of carbon monoxide and hydrogen with a Fischer-Tropsch catalyst and a hydrocracking / isomerization catalyst to obtain AGTL gasoline; and (b) step ( A blending step of mixing the AGTL gasoline and alkylate gasoline obtained in a) is included.

In the method for producing a clean gasoline composition of the present invention, the Fischer-Tropsch catalyst is a periodic table group 8 metal-supported silica, and the hydrocracking / isomerization catalyst is a periodic table group 8 metal-supported zeolite. preferable.
In the method for producing a clean gasoline composition of the present invention, it is preferable that the mixed gas of carbon monoxide and hydrogen is in contact with a Fischer-Tropsch catalyst and simultaneously or subsequently with a hydrocracking / isomerization catalyst. The Fischer-Tropsch catalyst and the hydrocracking / isomerization catalyst are preferably contacted under conditions of a temperature of 150 to 300 ° C. and a pressure of 0.1 to 10.0 MPa. Furthermore, Preferably, the C3-C4 hydrocarbon compound byproduced when manufacturing AGTL gasoline at the said process (a) is used as a raw material which manufactures the alkylate gasoline which uses at a process (b).

  The clean gasoline composition of the present invention can ensure sufficient driving characteristics, particularly high fuel efficiency, and greatly reduce the amount of sulfur oxides, carbon dioxide and hydrocarbons discharged to the environment, thereby reducing the burden on the environment. There is a special effect that it can be reduced. Further, according to the method for producing a clean gasoline composition of the present invention, AGTL gasoline used as a base material for the clean gasoline composition can be hydrogenated without subjecting the reaction product of Fischer-Tropsch synthesis to a special purification treatment. Since it can be obtained by purifying the decomposition / isomerization product obtained by supplying and contacting the decomposition / isomerization catalyst, purification after the Fischer-Tropsch synthesis is unnecessary, simplifying the process, saving energy, etc. Reduction of fixed costs and variable costs is expected.

  The clean gasoline composition of the present invention has a research octane number (RON) of 91 or more from the viewpoint of effectively improving fuel efficiency, preferably 91 to 96, more preferably 94 to 96, and 95 to 96. Are particularly preferred. This RON is measured by a method defined in JIS K 2280.

The sulfur content is preferably as low as possible from the viewpoint of reducing environmental burden, and is 1 mass ppm or less, preferably 0.5 mass ppm or less, and more preferably 0.1 mass ppm or less. This sulfur content is measured by the method defined in JIS K2541.
In order to prevent problems such as corrosion of a vehicle fuel sensor gauge due to a small amount of active sulfur, silver plate corrosion is preferably 1 or less and 0. This silver plate corrosion is measured by the method prescribed in British Petroleum Institute Standard IP-227.

  The vapor pressure is set to 65 kPa or less as a vapor pressure at 37.8 ° C. from the viewpoint of preventing deficiencies in operability due to low temperature startability, vapor lock, etc., and in particular, in the summer, 44 to 65 kPa, further 44 to 60 kPa. It is preferable that This vapor pressure is measured by a vapor pressure test method defined in JIS K 2258, a so-called lead method.

  The distillation volume of 50% by volume distillation temperature is preferably 95 ° C. or less, more preferably 80 to 95 ° C., from the viewpoints of exhaust gas reduction and acceleration improvement. The 50 vol% distillation temperature of this distillation property is measured by the method specified in JIS K 2254.

  In the clean gasoline composition of the present invention, the hydrogen / carbon ratio (mol) is preferably 2.3 or more, more preferably 2.3 to 2.4. In this way, when used as fuel, carbon dioxide emissions can be reduced. This hydrogen / carbon ratio is calculated from the contents of carbon and hydrogen measured by ASTM D5291-96 (hydrocarbon combustion method).

Further, the clean gasoline composition of the present invention preferably has an olefin content of 1% by volume or less, more preferably 0.1% by volume or less, and an aroma content, preferably 1% by volume or less, more preferably 0.1%. Set to volume% or less. The olefin content and aroma content are measured by a method defined in JIS K 2536 (fluorescent indicator adsorption method).
The olefin content and aroma content greatly contribute to the improvement of gasoline RON as described above, but it is not preferable from the viewpoints of environment such as carcinogenicity, particulate matter of exhaust gas, or storage stability. It is an ingredient. The clean gasoline composition of the present invention has succeeded in securing a high RON even when the olefin content and aroma content are reduced to very small amounts as described above.

AGTL gasoline and alkylate gasoline with low olefin content and aroma content are used as the base material of the clean gasoline composition.
When AGTL gasoline is used, hydrocarbons with a high hydrogen / carbon ratio can be easily obtained. This AGTL gasoline is obtained by treating carbon monoxide and hydrogen with the Fischer-Tropsch (FT) method and hydrocracking and isomerizing them without separating and removing them from unreacted substances, solvents and by-products. It is the gasoline that is used. The Fischer-Tropsch method is a method of synthesizing mainly normal paraffin (FT wax) by reacting carbon monoxide and hydrogen using a Fischer-Tropsch catalyst, and hydrocracking / isomerization. The treatment is a method for converting a long-chain normal paraffin to a short-chain isoparaffin in the presence of hydrogen using a hydrocracking / isomerization catalyst.
Further, alkylate gasoline is a high octane gasoline base material mainly composed of isoparaffin having 8 carbon atoms.

  The clean gasoline composition of the present invention can more easily adjust the RON to 91 or more by using an oxygen-containing compound.

  As the oxygen-containing compound, for example, alcohols having 2 to 5 carbon atoms and ethers having 4 to 8 carbon atoms are suitable. Specifically, alcohols such as ethanol, propyl alcohols, butyl alcohols, Ethers and esters which are derivatives from alcohols, such as ethyl isopropyl ether, ethyl tertiary butyl ether (ETBE), ethyl secondary butyl ether (ESBE), diisopropyl ether, tertiary amyl ethyl ether (TAEE), ethyl acetate, And ethyl propionate.

  The blending amount of these oxygen-containing compounds is preferably 1 to 15% by volume, more preferably 3 to 12% by volume, and even more preferably 5 to 10% by volume based on the total gasoline composition. If the amount is too small, the effect of addition is small. If the amount is too large, impurities such as moisture are accompanied, which may cause troubles such as corrosion of pipes and sealing materials. For example, since ethanol dissolves water infinitely, if it is contained too much in the fuel, there is a possibility that the water will be concentrated and accumulated in the automobile tank, causing adverse effects. In addition, when the fuel oil contains a large amount of oxygen-containing compounds, for example, if the amount exceeds 15% by volume, the air / fuel ratio of the existing engine will deviate from the appropriate value, resulting in an excess of oxygen. There is a drawback that the amount of nitrogen oxide (NOx) in the exhaust gas increases. Further, since oxygen-containing compounds generally have a lower calorific value than other gasoline base materials, and may reduce fuel consumption, it is not preferable to use too much.

  AGTL gasoline used in the clean gasoline composition of the present invention synthesizes long-chain saturated hydrocarbons (FT wax) from carbon monoxide and hydrogen using a Fischer-Tropsch catalyst, and hydrocracks the synthesized FT wax.・ Manufactured by hydrocracking into short-chain hydrocarbons using an isomerization catalyst and at the same time hydrocracking and isomerizing isomerizing normal paraffins into isoparaffins. In performing these steps (FT synthesis and hydrocracking / isomerization), the FT catalyst and the hydrocracking / isomerization catalyst may be used in two stages as described later, or You may mix and use it as one step.

In the production of the AGTL gasoline, preferably, the FT reaction product is not separated from unreacted substances, solvent, by-products, etc., removed, or hydrocracked / isomerized without being diluted with nitrogen or carbon dioxide. Sent to the process. This is because the reaction product is purified in the FT synthesis process and only the FT wax is taken out, and then supplied to the hydrocracking / isomerization process. The obtained hydrocracking / isomerization product is purified to obtain the target GTL gasoline. Compared with the method for obtaining the above, it is different in that hydrocracking / isomerization treatment is performed without separating / removing water, unreacted substances, lower hydrocarbons, solvents, and the like generated by the FT reaction. Therefore, since only the reaction product of the hydrocracking / isomerization process needs to be purified, it is not necessary to equip the purification equipment twice. In addition, since the reaction conditions (reaction temperature, pressure, etc.) of both steps may be substantially the same, the reaction product of the FT synthesis step can be supplied as it is to the hydrocracking / isomerization step without cooling or heating, saving energy. is there. In this way, when the reaction product of the FT synthesis process is supplied to the hydrocracking / isomerization process as it is, the reactor filled with the FT catalyst and the reactor filled with the hydrocracking / isomerization catalyst are connected to this reactor. They may be provided in series in order, or the inside of one reactor can be used in two stages in this order.
Unreacted substances generated in the purification process for obtaining AGTL gasoline can be recycled for the FT synthesis process, and hydrocarbons heavier than AGTL gasoline can be recycled for the hydrocracking / isomerization process.

  Furthermore, in the method for producing a clean gasoline composition of the present invention, a mixed gas of carbon monoxide and hydrogen is brought into contact with a mixed catalyst of a Fischer-Tropsch catalyst and a hydrocracking / isomerization catalyst at one time to generate FT synthesis and hydrogen. Chemical decomposition and isomerization can also be performed.

  The FT synthesis uses an FT catalyst, uses a mixed gas of hydrogen and carbon monoxide at a ratio of hydrogen / carbon monoxide = 2/1 or more (molar ratio) as a raw material, and further uses, for example, normal hexane as a solvent. To do. Reaction is mixed gas / normal hexane = 1.0 / 0.1 to 1.0 / 10.0 (molar ratio), reaction temperature 150 to 300 ° C., reaction pressure 0.1 to 10.0 MPa, mixed gas flow rate 10 It can be carried out under a condition of ˜200 ml / min. / G. More preferably, hydrogen / carbon monoxide = 3/1 or more (molar ratio), mixed gas / normal hexane = 1.0 / 1.0 to 1.0 / 5.0 (molar ratio), reaction temperature 200 to 250. ° C, reaction pressure 0.5 to 4.5 MPa, mixed gas flow rate 40 to 100 ml / min. / G. Periodic table group 8 metal-supported silica can be preferably used as the FT catalyst. Examples of the Group 8 metal of the periodic table include platinum, palladium, ruthenium, rhodium, iridium, osmium, iron, cobalt, and nickel. Of these, ruthenium, iron and cobalt are preferable, and cobalt is particularly preferable. The supported amount of Group 8 metal of the periodic table is preferably 1 to 20% by mass, more preferably 5 to 15% by mass in terms of metal. The shape of the carrier or the shape of the catalyst is not limited, but columnar molded products, three-leaf / four-leaf molded products, spherical products, tablet-molded products, granular products, and the like are used.

  Hydrocracking and isomerization can be performed under reaction conditions of a reaction temperature of 150 to 300 ° C., a reaction pressure of 0.1 to 10.0 MPa, and a mixed gas flow rate of 10 to 200 ml / min. / G, and more preferably a reaction The temperature is 200 to 250 ° C., the reaction pressure is 0.5 to 4.5 MPa, and the mixed gas flow rate is 40 to 100 ml / min. / G. A periodic table group 8 metal-supported zeolite can be used as the catalyst. Examples of the Group 8 metal of the periodic table include platinum, palladium, ruthenium, rhodium, iridium, osmium, iron, cobalt, and nickel. Platinum, palladium, and ruthenium are preferably used, and palladium is particularly preferably used. The supported amount of Group 8 metal of the periodic table is preferably 0.1 to 10% by mass, more preferably 0.15 to 1.0% by mass. As the zeolite carrier, USY zeolite is preferable, and β-type zeolite is more preferable.

  The mixed gas of carbon monoxide and hydrogen is brought into contact with the FT catalyst under the above conditions together with normal hexane to produce FT wax. The FT wax is sent to the hydrocracking / isomerization step together with the produced water, unreacted raw material gas and reaction intermediate, and in contact with the hydrocracking / isomerization catalyst under the above conditions, the FT wax has a length of 15 or more. Most of the chain hydrocarbons are converted into hydrocarbons having 15 or less carbon atoms, and normal paraffins are further isomerized and converted into isoparaffins. Unreacted raw material gas, generated water, fuel gas such as methane and ethane, hydrocarbons having 3 and 4 carbon atoms such as propane, normal butane, and isobutane, and heavy hydrocarbon and wax that cannot be used as a gasoline base material Can be removed by distillation or other known appropriate unit operations to obtain a gasoline fraction, that is, AGTL gasoline.

  The above AGTL gasoline finally has a RON of 91 or more and a hydrogen / carbon ratio of 2.3 or more, so that it can be more easily prepared with respect to the total amount of the gasoline composition, 20-80. It is preferable to contain by volume.

  Normal hexane keeps the reaction system in a supercritical state, has the effect of promoting the reaction by dispersing the reaction product from around the catalyst, and also has the effect of cleaning and removing coke that is by-produced and deposited. . Normal hexane is not essential, and the reaction proceeds without using it, and isoparaffin can be obtained.

The gasoline composition according to the present invention can be prepared by blending AGTL gasoline and alkylate gasoline. Furthermore, it is preferable to mix an oxygen-containing compound as appropriate. Other known gasoline base materials such as LPG (particularly so-called BB fraction), pentane (particularly isopentane), desulfurized straight-run naphtha (light and heavy), catalytic reformed gasoline (so-called hall contact) Reformed gasoline, fractionated catalytically reformed gasoline mainly composed of hydrocarbons having 7 to 9 carbon atoms, desulfurized catalytic cracked gasoline (so-called catalytic cracking gasoline in holes, or fractionated catalytically cracked gasoline, and these (Desulfurized product) may be blended. In preparing this gasoline composition, RON, sulfur content, vapor pressure, distillation properties, silver plate corrosion, carbon dioxide generation amount per calorific value, etc. of the above various gasoline base materials are measured or calculated in advance. By blending to the above specific range, it can be produced relatively easily.
In addition, as a preferable compounding quantity, it is 20-80 volume% of AGTL gasoline, 20-80 volume% of alkylate gasoline, and 0-15 volume% of ETBE.

  The alkylate gasoline used in the present invention is produced by a generally performed method (alkylation). Specifically, a hydrocarbon (alkylate gasoline) having a high isoparaffin (isooctane) content can be obtained by reacting a fraction containing butylene as a main component with a fraction containing isobutane as a main component using a sulfuric acid catalyst. In addition, the use of hydrocarbons having 3 or 4 carbon atoms, which are by-produced during the synthesis of the AGTL gasoline, that is, propane, normal butane, and isobutane as raw materials for this alkylation is from the viewpoint of securing raw materials and effective utilization of by-products. Particularly preferred. In addition to the sulfuric acid, a liquid catalyst such as hydrofluoric acid, a phosphoric acid-based catalyst, a solid superacid catalyst represented by zirconia sulfate or zirconia tungstate can be used as the alkylation reaction catalyst.

  As a preferred embodiment of the clean gasoline composition of the present invention, a known fuel additive can be blended as necessary. Although these compounding quantities can be selected suitably, it is usually preferable to set it as 0.1 mass% or less as a total amount of an additive. Examples of additives that can be used in the carbon dioxide low emission gasoline composition of the present invention include amine-based, phenol-based, aminophenol-based antioxidants, Schiff-type compounds, thioamide-type compounds, and other metal deactivators. , Surface ignition inhibitors such as organophosphorus compounds, detergent dispersants such as succinimides, polyalkylamines and polyetheramines, anti-icing agents such as polyhydric alcohols and their ethers, alkali metal salts and alkaline earths of organic acids Metal salts, auxiliary agents such as sulfates of higher alcohols, anionic surfactants, cationic surfactants, antistatic agents such as amphoteric surfactants, rust inhibitors such as alkenyl succinates, quinizarin, coumarins, etc. And a colorant such as an azo dye.

  Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to these examples.

The FT synthesis catalyst was prepared by the following method.
Cobalt nitrate aqueous solution was impregnated into a carrier of silica Q-15 manufactured by Fuji Silysia, dried, and calcined at 400 ° C. to obtain a Co-supported SiO ₂ catalyst. The ratio of the supported metal in the catalyst was 10.0% by mass as cobalt element. The carrier was used as a granular size of 0.4 to 0.7 mm using a 20 to 40 mesh sieve after pulverizing the molded product pellets.

The hydrocracking / isomerization catalyst was prepared by the following method.
Tosoh β-type zeolite was ion-exchanged at 80 ° C. using a palladium chloride ammine salt aqueous solution, dried, and calcined at 450 ° C. to obtain a Pd-supported β-type zeolite catalyst. The proportion of the metal in the catalyst was 0.3% by mass as palladium element. The carrier was used as a granular size of 0.4 to 0.7 mm using a 20 to 40 mesh sieve after pulverizing the molded product pellets.

  The gasoline base material having the properties shown in Table 1 was blended at the blending ratio shown in the upper part of Table 2 to prepare gasoline compositions serving as examples and comparative examples. The gasoline base used was prepared as follows.

The AGTL gasoline catalyst is a mixture of 0.5 g of FT synthesis catalyst and 0.5 g of hydrocracking / isomerization catalyst, and a mixed gas composed of hydrogen and carbon monoxide is used as a raw material, with a reaction temperature of 240 ° C. and a reaction pressure of 4. The reaction was carried out under the conditions of 5 MPa, hydrogen / carbon monoxide = 2/1 (molar ratio), mixed gas / normal hexane = 1.0 / 3.5 (molar ratio), and mixed gas flow rate 81 ml / min. The reaction product was distilled to remove light and heavy components to obtain AGTL gasoline.

Isopentane (iC5)
A gasoline fraction obtained by distilling crude oil, or a gasoline fraction by-produced in various refinery refining processes, was obtained by hydrodesulfurization and precision distillation if necessary.

Desulfurization straight naphtha fraction (DSLG)
A gasoline fraction obtained by distilling Middle Eastern crude oil was hydrodesulfurized and then separated by distillation to obtain a lighter fraction. This desulfurized straight-run naphtha fraction is characterized by containing almost no aroma or olefin.

Alkylate gasoline (ALKG)
A fraction containing butylene as a main component and a fraction containing isobutane as a main component were reacted with a sulfuric acid catalyst to obtain a hydrocarbon having a high carbon content of isoparaffin having 8 carbon atoms (ALKG).

Catalytic reforming gasoline fraction (AC9)
Desulfurization straight-run heavy naphtha, which is separated from the gasoline fraction after hydrodesulfurization by distillation and removed light components (desulfurization straight-run naphtha cut (DSLG)), is reacted with a solid reforming catalyst using a moving bed reactor. As a result, the reformed gasoline is reformed into a hydrocarbon having a high aroma content. The reformed gasoline is often used as it is after adjusting the vapor pressure, but here, a fraction (AC9) containing 95% or more of aromatic hydrocarbons having 9 carbon atoms was obtained by distillation separation.

Desulfurization catalytic cracking gasoline fraction (FCCG)
Hydrocarbons with high olefin content were obtained by cracking desulfurized light oil or desulfurized heavy oil with a solid catalyst using a fluidized bed reactor. Furthermore, hydrocarbons having a low sulfur content were obtained by collecting and removing FCCG. After sulfiding a catalyst in which 20% by mass of nickel was supported on alumina, the Middle East region was subjected to a reaction temperature of 250 ° C., a reaction pressure of normal pressure, a liquid space velocity (LHSV) of 4 h ⁻¹ , and a hydrogen / oil ratio of 340 NL / L. Diene reduction treatment was carried out by passing the catalytically cracked gasoline fraction obtained by fluid catalytic cracking, which was obtained by hydrorefining the crude oil reduced-pressure gas oil fraction as the main feedstock. Then, the reduction process of the copper- zinc aluminum complex oxide (copper content 35 mass%, zinc content 35 mass%, aluminum content 5 mass%) prepared by the coprecipitation method was performed. Thereafter, the diene-treated catalytically cracked gasoline was allowed to pass through for 20 hours under the conditions of a reaction temperature of 100 ° C., a reaction pressure of normal pressure, LHSV of 2.0 h ⁻¹ , and a hydrogen / oil ratio of 0.06 NL / L, so A desulfurized catalytic cracking gasoline fraction (FCCG) desulfurized with a desulfurizing agent having a water content was obtained. This fraction contains 17% aroma and 26% olefin.

Ethyl tertiary butyl ether (ETBE)
Ethanol and isobutylene were reacted in the presence of an ion exchange resin catalyst (Amberlyst-15) and purified by distillation to obtain 95% pure ETBE.

In addition, the property of the gasoline base material and the prepared gasoline composition was measured by the following method.
The density was measured by the density test method of JIS K 2249, the vapor pressure of the Reed method was measured by the vapor pressure test method (Reed method) of JIS K 2258, and the distillation property was measured by the atmospheric pressure distillation test method of JIS K 2254. The sulfur content was measured by the sulfur content test method of JIS K2541.

  About the Example, the gasoline base material was blended by the mixing ratio of Table 2, and clean gasoline was manufactured. Compared with the conventional gasoline of Comparative Example 1, the gasoline of Example 1 has a high RON and a high hydrogen / carbon ratio even though it contains almost no aroma or olefin content. It turns out that it is a thing.

  In addition, the gasolines of Example 2 and Example 3 contain ETBE, and by containing an oxygen-containing compound, they have a high RON, a high hydrogen / carbon ratio, and an appropriate distillation property. On the other hand, in the gasoline not using the AGTL gasoline of Comparative Example 2 and Comparative Example 3 containing oxygen-containing compounds in the same manner, even if only the base material containing no aroma or olefin is used, a distillation volume of 50% by volume is obtained. Outlet temperature is not satisfactory, RON is low, or hydrogen / carbon ratio is low. As described above, it can be seen that clean gasoline having excellent practical performance can be obtained by using AGTL gasoline.

Industrial application fields

  The clean gasoline composition of the present invention has a very low sulfur content and a high content of branched saturated hydrocarbon compounds. Therefore, the clean gasoline composition is suitable as a fuel for gasoline engines, has a low environmental burden, and has high energy efficiency. have. In addition to this, since it is a hydrocarbon with a small amount of impurities that become catalyst poisons and a relatively high hydrogen content, it is also suitable as a fuel for fuel cells. Of course, it can also be used as a gasoline common to gasoline engines and fuel cells.

Claims (8)

From a reaction product obtained by contacting a mixed gas of carbon monoxide and hydrogen with a Fischer-Tropsch catalyst and simultaneously or subsequently with a hydrocracking / isomerization catalyst , unreacted raw material gas, produced water, methane, ethane, etc. Fuel gas, C3 and C4 hydrocarbons, heavy hydrocarbons that cannot be gasoline base materials, AGTL gasoline that is a gasoline fraction obtained by removing wax, and alkylate gasoline The vapor pressure at 37.8 ° C. is 65 kPa or less, the research octane number is 91 or more, the sulfur content is 1 mass ppm or less, the silver plate corrosion is 1 or less, the 50% by volume distillation temperature of distillation property is 95 ° C. or less, the aroma content Is a clean gasoline composition having an olefin content of 1% by volume or less, a hydrogen / carbon ratio (mol) of 2.3 or more.   Furthermore, the clean gasoline composition of Claim 1 containing an oxygen-containing compound.   The clean gasoline composition according to claim 1 or 2, further comprising at least one gasoline base selected from the group consisting of liquefied petroleum gas, isopentane, desulfurized straight naphtha, catalytic reformed gasoline, and desulfurized catalytic cracked gasoline. .   The clean gasoline composition according to any one of claims 1 to 3, which is used as a fuel for a gasoline engine or a fuel for a fuel cell. (A) From a reaction product obtained by contacting a mixed gas of carbon monoxide and hydrogen with a Fischer-Tropsch catalyst and simultaneously or subsequently with a hydrocracking / isomerization catalyst , unreacted raw material gas, produced water, methane A process for obtaining a fuel gas such as ethane, hydrocarbons having 3 or 4 carbon atoms, heavy hydrocarbons that cannot be gasoline base materials, AGTL gasoline that is a gasoline fraction obtained by removing wax , and (B) A blending step of mixing the AGTL gasoline and alkylate gasoline obtained in the step (a) is included, the vapor pressure at 37.8 ° C. is 65 kPa or less, the research octane number is 91 or more, the sulfur content Is 1 mass ppm or less, silver plate corrosion is 1 or less, distillation volume of 50% by volume distillation temperature is 95 ° C. or less, aroma content is 1% by volume or less, olefin content is 1% by volume or less, and hydrogen / A method for producing a clean gasoline composition having a carbon ratio (mol) of 2.3 or more.   6. The method for producing a clean gasoline composition according to claim 5, wherein the Fischer-Tropsch catalyst is a Periodic Table Group 8 metal-supported silica, and the hydrocracking / isomerization catalyst is a Periodic Table Group 8 metal-supported zeolite.   The method for producing a clean gasoline composition according to claim 5 or 6, wherein the Fischer-Tropsch catalyst and the hydrocracking / isomerization catalyst are contacted under conditions of a temperature of 150 to 300 ° C and a pressure of 0.1 to 10.0 MPa.   The hydrocarbon compound having 3 to 4 carbon atoms by-produced when producing AGTL gasoline in the step (a) is used as a raw material for producing the alkylate gasoline used in the step (b). The manufacturing method of the clean gasoline composition of description.