JP2010522249A - Fischer-Tropsch derived diesel fuel and method for producing the same - Google Patents

Abstract

The present invention has a flash point of at least 38 ° C. and a cloud point of + 14 ° C. or lower as measured by ASTM D93, and further 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol. As distillate fuels, each containing 1-decanol oxygen in an amount not less than 0.01% by weight and C ₁₁₊ linear alcohol in an amount not more than 0.01% by weight Fischer-Tropsch derived distillate suitable for use. Preferably, the Fischer-Tropsch distillate has a cloud point of 0 ° C. or less, and more preferably, the Fischer-Tropsch distillate has a cloud point of −15 ° C. or less.

Description

(Field of Invention)
The present invention relates to Fischer-Tropsch diesel fuels, distillate fuels or blend components that meet the specifications for diesel fuels but have a lower density compared to conventional diesel fuels, and to methods for producing such fuels.

(Background of the Invention)
Distillate fuel contains components that boil above the typical gasoline endpoint (about 400 degrees Fahrenheit or 204 ° C), but does not contain components that cannot be distilled (components that boil above 1100 degrees Fahrenheit or 593 ° C) Represents fuel. The distillate fuel can be burned in a stationary engine such as, for example, a fuel used to generate electricity. Diesel fuel represents distillate that can be burned in a diesel engine that powers various human activities. Diesel fuel specifications are more stringent than distillate fuel specifications. As an example in the United States, the end point specification of diesel fuel is No. For 2-D, it is 640 Fahrenheit (338 ° C.); 1-D is 550 degrees Fahrenheit (288 ° C.).

  Various qualities of diesel fuel have specifications with limits on cloud points. These often vary with geographic area and time. As an example, ASTM D975-00 is a No. 1 in the United States. 1-D and No. The specification of 2-D diesel fuel is established. This specification includes a description as an annotation in Table 1, where “The lowest air temperature in the 10 out of 100 groups in the US region is listed in Appendix X4 as a means of estimating the expected local temperature. This guideline is a general guideline. Some equipment designs or operations may tolerate higher cloud points, or may require fuels with lower cloud points. " Is included. The temperature of this Appendix X4 ranges from -49 ° C in January in northern Alaska to + 14 ° C in October in southern Florida. Similarly, the World Wide Fuel Charter (2002) includes a description of the cloud point “highest must be equal to or lower than the lowest expected ambient temperature”. Thus, accepted diesel fuel has a cloud point of + 14 ° C. or lower, such as 0 ° C. or lower, or −15 ° C. or lower, alternatively −25 ° C. or lower, or −49 ° C. or lower. Must be.

  Due to their highly paraffinic composition, their density may be below specification. If the specified density of conventional diesel fuel needs to be maintained, these compositions according to the present invention are best used as a blend raw material.

  The Fischer-Tropsch process provides a way to convert various hydrocarbonaceous resources into products normally provided by petroleum. These include diesel fuel. In the production of hydrocarbons through the Fischer-Tropsch process, hydrocarbon resources such as natural gas, coal, refinery fuel gas, tar sand, oil shale, municipal waste, agricultural waste, forest waste, wood, shale Oil, asphalt, crude oil, and fractions from crude oil, etc. are first converted to synthesis gas, which is a mixture containing carbon monoxide and hydrogen.

The synthesis gas generation method is a method for converting a hydrocarbon-based product into synthesis gas by using a gaseous oxidant. The gaseous oxidant can be purified O ₂ , concentrated air, air, water vapor, carbon dioxide and combinations thereof. This method can occur either on the ground or at the original location. Examples of on-ground syngas generation methods that use gaseous hydrocarbons having a carbon number of less than 20 (eg, methane) as the feedstock for the reaction tower include the Automatic Thermal Reformer (ATR) ), Partial Oxidation (POX), Gas Heater Reformer (GHR), and Steam Reforming (steam reforming). When these feedstocks contain more C ₂ and heavier hydrocarbons than 2 mol%, preliminary converter (pre-reformer) are often used to convert the C 2 ₊ hydrocarbons to methane. In this pre-reformer, a catalyst containing a Group VIII metal catalyst (eg, Ni) under superatmospheric pressure is used with hydrogen. Examples of syngas production are described in Kirk Somer On-line Edition “Fuels, Synthetic, Liquid Fuels”, particularly Chapters 1–2 on-line publication, which is incorporated herein by reference.

  And the same online reference, “Methanol 4. Manufacture and Processing”, pages 299-311, which is incorporated herein by reference.

  Syngas can also be generated by the reaction of underground hydrocarbonaceous resources with gaseous oxidants. An example of this in-situ method is described in US Pat. No. 6,698,515 issued March 2, 2004 to Karanikas et al. Examples of underground hydrocarbon-based resources are coal, heavy oil, tar sand, petroleum deposits and asphalt. Examples of petroleum deposits suitable for in-situ conversion include petroleum deposits from easily extracted petroleum extracted by conventional methods such as pump pumping, steam water flooding and water flooding. .

  The synthesis gas is then converted into a synthetic hydrocarbon-based compound having primarily a linear structure, primary n-paraffin, 1-alcohol, 1-olefin, and trace amounts of other components. These types of hydrocarbons can be reformed into various products including distillate fuel.

European Patent Nos. 0861111, 08827575, U.S. Patent Nos. 5689031, 6274029, 6296757, 6607568, 6822131 are C _{5 to} C ₂₄ primary linear alcohols, preferably The production of Fischer-Tropsch derived products containing primary linear alcohols C ₁₂ -C ₂₄ , or C ₁₂₊ primary linear alcohols is disclosed. It is not clear what type of primary linear alcohol is assumed to be included. However, these middle distillates have a lower density than diesel fuel specifications. The presence of alcohol is claimed to improve the lubricity of middle distillate fuel. Unfortunately, the compositions taught in these materials that use a specific alcohol range, particularly those that use C ₁₁₊ alcohols, are not compatible with the cloud point specification for diesel fuels, and therefore these The composition is not suitable as a commercial diesel fuel. The present invention seeks to demonstrate that the alcohol should be C ₁₀ and below, and in particular the Fischer-Tropsch can be adapted to the cloud point and preferably has enhanced yield in the process. The invention relates to a derived diesel fuel composition.

  The cloud point represents a temperature below that at which solid hydrocarbons can be formed in diesel fuel. The cloud point is measured by ASTM D2500 which measures the fuel temperature at which solid hydrocarbon crystals are formed upon cooling.

  As used herein, the term “Fischer-Tropsch derived” means that, with the exception of added hydrogen, a substantial portion is independent of the subsequent processing steps and independent of the synthesis gas production method. Represents a hydrocarbon stream that is derived from the Fischer-Tropsch process. The feedstock for the production of “Fischer-Tropsch derived” materials is all carbon sources such as natural gas, coal, refined fuel gas, oil shale, municipal waste, agricultural waste, forest waste, wood, shale oil Represents products derived from, for example, asphalt, crude oil, and fractions from crude oil.

  As used herein, the term “comprising” or “comprising” includes the listed elements, but does not necessarily exclude other unlisted elements. It shall have. The expression “consisting essentially of” or “consisting essentially of” shall have the meaning of excluding elements other than all the basic element specifications of the composition. The expression “consisting of” or “consisting of” shall have the meaning of unlimited change, except that all but the specified elements are excluded, but only the trace amount is not excluded as an impurity. .

(Summary of the Invention)
The present invention has a flash point of at least 38 ° C. and a cloud point of + 14 ° C. or lower as measured by ASTM D93, and further 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol. And at least two oxygens of 1-alcohol of 1-decanol in an amount which is not less than 0.01% by weight, and oxygen of C ₁₁₊ linear alcohol is more than 0.01% by weight. Relates to a Fischer-Tropsch derived distillate which is suitable for use as a diesel fuel containing no amount. Mixtures of C ₅ -C ₁₀ alcohol all are within the scope of the present invention. The upper limit of oxygen weight percent of alcohol is in an amount less than that of a fuel that does not meet the appropriate cloud point and / or other fuel specifications. Optionally, two of the three alcohols are 0.03% by weight of oxygen in these two, ie, C ₅ and C ₇ , or C ₅ and C ₆ , or oxygen in C ₆ and C _7. It can be used in an amount that is a concentration that is never less. Fischer-Tropsch derived distillate fuel has a cloud point of + 14 ° C. or lower, such as 0 ° C. or lower, alternatively −15 ° C. or lower, alternatively −25 ° C. or lower, or −49 ° C. or lower. . All oxygen weight percentages are on a water free basis. If the density is part of a diesel fuel specification, Fischer-Tropsch diesel may contain auxiliary components to reach the appropriate density specification.

It is useful to summarize the boiling points of various paraffins and alcohols:

In order to achieve a flash point of 38 ° C. according to ASTM D93, the boiling point needs to be 250 degrees Fahrenheit (121 ° C.) or higher. Since the boiling points of paraffin and alcohol are different, this corresponds to n-C ₈ and 1-pentanol. Similarly, C ₁₁₊ alcohols should be excluded by the use of distillation, and if they boil at 495 degrees Fahrenheit (257 ° C.) or higher, this will boil at n-C ₁₄ or higher, eg, C ₁₅₊ product. Corresponds to paraffin. No. 2-D diesel fuel end point 640 degrees Fahrenheit (338 ° C.) is true when the paraffin or less than _{C 20,} or _{C 20.} It can include several molecular chain paraffins to C _24. No. 1-D endpoints 550 ° F. Diesel Fuel (288 ° C.), either the paraffin is less than _{C 16,} or it applies to equal to _{C 16,} slightly branched paraffins to _{C 18} includes Sometimes. If the alcohol is added from a source other than the FT reaction stream product, this cut point can be higher because there is no harmful higher alcohol.

The present invention also allows the upgrade of C ₁₅₊ product by alcohol in the lighter fraction and produces Fischer-Tropsch derived diesel fuel, preferably in the highest yield, by retaining the C ₁₄₋ product. Regarding the method. This method comprises (a) separating a Fischer-Tropsch concentrate into a first fraction and a second fraction, wherein (i) the first fraction is 1-pentanol, 1-hexanol, 1-heptanol, 1- Oxygen from at least two of octanol, 1-nonanol, and 1-decanol is included in an amount not less than 0.01% by weight, and oxygen in C ₁₁₊ linear alcohol is from 0.01% by weight And (ii) the second fraction contains C ₁₁₊ linear alcohol; (b) separate C ₁₁₊ linear alcohol from at least a portion of the heavy third fraction; ₁₁₊ recover the treated heavy fraction substantially free of linear alcohol; then (c) the first phase of step a (i) At least a portion of the fraction and a portion of the treated heavy fraction of step (b) are mixed at an appropriate ratio so that the total oxygen-feeding substance content of the C ₅ -C ₁₀ alcohol present is 0.01 wt% oxygen Including producing a Fischer-Tropsch derived distillate fuel that is within the range of 1 wt% oxygen, has a cloud point never higher than + 14 ° C, and has a flash point of 38 ° C minimum as measured by ASTM D93. Yes. This flash point is generally applicable when 121 ° C. (250 degrees Fahrenheit) is the lowest 5% point as measured by ASTM D2887. In carrying out the process of the invention, the third fraction can be separated from the Fischer-Tropsch concentrate in step (a) containing C4 _- linear alcohol.

The present invention finds that the presence of oxygen in the C ₁₁₊ linear alcohol in an amount greater than 0.01% by weight significantly increases the cloud point of the composition, making it unsuitable for use as a diesel fuel. Based on. Further processing of the C ₁₅₊ fraction can also increase the yield. This is because C14 _- paraffin is suitable for use in diesel fuel. As used herein, the term “C ₄ -linear alcohol” refers to a linear alcohol containing 4 or less carbon atoms in the molecule, such as methanol, ethanol, 1- Represents butanol and 1-propanol. The term “C ₁₁₊ linear alcohol” means a linear alcohol containing 11 or more carbon atoms in the molecule, such as 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, Represents linear alcohols such as 1-pentadecanol and 1-hexadecanol. Linear _C 5 _{-C 10} alcohol 1-pentanol, 1-represented hexanol, Putanoru to 1, 1-octanol, 1-nonanol, and decanol, and mixtures thereof.

(Detailed description of the invention)
The present invention is based on the discovery that in a Fischer-Tropsch derived distillate fuel, the presence of oxygen in the C ₁₁₊ linear alcohol as low as 0.01% by weight raises the cloud point to an unacceptable temperature. Surprisingly, the presence of C _{5 to} C ₁₀ linear alcohols in the same fuel, more particularly 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, and 1-decanol, is cloudy. It has a non-negligible effect on the point. Small amounts of other types of alcohols and alcohols with higher carbon numbers can be included as long as the cloud point of the diesel fuel meets its specifications. This generally means that other types of alcohol are present only as impurities. Furthermore, the problem to be solved was to reduce the cost of producing diesel fuel by reducing the severity of hydroprocessing operations that increase yield while meeting the cloud point specifications for diesel fuel.

In the method of the present invention, the Fischer - Tropsch product (concentrate, wax or blend) separating at least two fractions, namely a first fraction and heavy fraction containing C ₁₀ and further lower alcohol. Preferably, the light fraction contains less than 0.01% by weight of at least two of the 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, and 1-decanol. And the C ₁₁₊ linear alcohol has an amount of oxygen not greater than 0.01% by weight, and the second heavy fraction contains C ₁₁₊ linear alcohol. A portion of the heavy second fraction that is compounded back to the first fraction is subjected to a treatment that removes substantially all of the C ₁₁₊ linear alcohol present. Finally, this treated heavy second fraction is mixed with at least a portion of the first fraction in a calculated amount to produce a Fischer-Tropsch distillate fuel having a cloud point that is never below + 14 ° C. In general, the total oxygen-feeding substance content of C ₅ -C ₁₀ alcohols present in a Fischer-Tropsch derived distillate fuel falls within the range of 0.01 wt% oxygen to 1 wt% oxygen. Any two of a combination of alcohol, namely the combination of _{C 5} and _{C 6} or _{C 5} and _{C 7} or _{C 6} and _{C 7,} 0.01 wt% of oxygen, preferably from 0.03 wt% oxygen It can be present in an amount up to 1.0 wt% oxygen. The fuel should also preferably have a flash point of at least 38 ° C. as measured by ASTM D93. Unless blended with conventional petroleum feedstock, its density is below standard, but it can still function effectively as distillate and diesel fuel.

The product (concentrate, wax or blend) recovered from the Fischer-Tropsch operation contains oxygen feed materials in various amounts. Most of the oxygen-providing substances present are in the form of alcohols, but ketones, aldehydes, carboxylic acids and anhydrides may be present in small amounts. To prepare heavy fraction does not substantially contain the the C ₁₁₊ linear alcohols, there is a need to convert or remove the C ₁₁₊ linear alcohols or those in other types of hydrocarbons. Many methods are known to those skilled in the art that can be used to perform this step. These methods include, but are not limited to, hydroprocessing, hydrocracking, hydroisomerization, dehydration, adsorption, absorption or various combinations of these processes. As used herein, “substantially free of C ₁₁₊ linear alcohol” is a concentration at which the distillate fraction increases the cloud point of the distillate fraction to a higher value than the diesel fuel specification. Means containing C _{11 +} alcohol in less than amount.

  Hydrocracking and hydrotreating are similar processes that differ primarily in their severity. In the present specification, these treatments can be collectively represented by the term “hydroprocessing”. In the process of the present invention, hydrocracking and hydrotreating are primarily aimed at removing alcohol present in the Fischer-Tropsch distillate. “Hydrotreating” refers to a catalytic treatment usually performed in the presence of free hydrogen, the main purpose of which is to use various metal contaminants from the feedstock when used to treat conventional petroleum-derived feedstocks. In the removal of products such as arsenic; heteroelements such as sulfur and nitrogen; and aromatics. In the process of the invention, the main purpose is to remove the alcohol and, secondly, to saturate the olefin present. In general, in hydroprocessing operations, the decomposition of hydrocarbon molecules, ie, the decomposition of larger hydrocarbon molecules into smaller hydrocarbon molecules, is minimized. For the purposes of this discussion, the term hydroprocessing refers to a hydroprocessing operation with a conversion rate of 20% or less. Conversion can be defined as being based on an increase in the amount of material that boils below the 5% point of the feedstock as measured by ASTM D2887 in the product relative to the feedstock. “Hydrogenolysis” usually refers to a catalytic operation performed in the presence of free hydrogen, in which case the main purpose of this operation is the decomposition of the larger hydrocarbon molecule. Unlike hydrotreating, the conversion rate of hydrocracking is higher than 20% for the purposes of this specification. In the present invention, hydrogenolysis is used for alcohol separation and olefin hydrogenation.

  Catalysts used to perform hydroprocessing and hydrocracking operations are well known to those skilled in the art. For example, U.S. Pat. Nos. 4,347,121 and 4,810,357 may be referred to, as a general description of hydrotreating, hydrocracking and representative catalysts used in these treatments. Are incorporated herein by reference in their entirety. Suitable catalysts are noble metals from Group VIIIA (according to the International Union of Pure and Applied Chemistry 1975 rules), such as platinum or palladium on an alumina or silicon matrix, and non-sulfurized Group VIIIA and Group VIB, such as alumina. Or nickel-molybdenum or nickel-tin on a silicon matrix. U.S. Pat. No. 3,852,207 discloses suitable noble metal catalysts and mild conditions. Other suitable catalysts are disclosed, for example, in U.S. Pat. Nos. 4,157,294 and 3,904,513. Non-noble metal hydrogenation catalysts such as nickel-molybdenum are usually present in the final catalyst composition as oxides, or preferably, if possible, as sulfurized compounds when readily generated from the particular metals involved. . Preferred non-noble metal catalyst compositions are 5% or more oxygen, preferably 5 to 40% oxygen by weight molybdenum and / or tungsten and at least 5% by weight, generally 1 to 15% by weight, measured as the corresponding oxide. Contains oxygen nickel and / or cobalt. A catalyst containing a noble metal, such as platinum, contains 0.01% or more metal, preferably 0.1 to 1.0% metal. A combination of noble metals can also be used, for example a mixture of platinum and palladium.

  The hydrogenation component can be incorporated into the overall catalyst by any one of a number of methods. The hydrogenation component can be added to the matrix component by co-mixing, impregnation or ion exchange, and the Group VI components, namely molybdenum and tungsten, can be formulated by impregnation, co-mixing or co-precipitation. These components can be incorporated into the catalyst matrix as sulfurized compounds, but sulfur compounds are generally not preferred because sulfur components can interfere with the Fischer-Tropsch catalyst.

  The matrix component can be many types of components including those having acidic catalytic activity. If active, amorphous silica-alumina is included or can be a zeolite or non-zeolitic crystalline molecular sieve. Examples of suitable matrix molecular sieves are Zeolite Y, Zeolite X and Zeolite Y which is said to be ultrastable and, for example, U.S. Pat. Nos. 4,401,556, 4,820,402 and 5, Includes high structural silica: alumina ratio zeolite Y as described in US Pat. No. 059,567. Small crystal size zeolite Y can also be used, for example as described in US Pat. No. 5,073,530. Non-zeolite molecular sieves that can be used include, for example, silicoaluminophosphate (SAPO), ferroaluminophosphate, titanium aluminophosphate and various ELAPOs described in US Pat. No. 4,913,799 and references cited therein. Includes molecular sieve. Details relating to the production of various non-zeolitic molecular sieves can be found in US Pat. Nos. 5,114,563 (SAPO) and 4,913,799 and various references cited in US Pat. No. 4,913,799. Can be found in Interporous molecular sieves can also be used, e.g. Am. Chem. Soc. 114: 10834-10843 (1992), Group M41S, MCM-41; U.S. Pat. Nos. 5,246,689; 5,198,203; and 5,334,368. As well as MCM-48 (Kresge et al., Nature 359: 710 (1992)). Suitable matrix materials are also synthetic or natural materials, as well as inorganic materials such as clays, silica and / or metal oxides such as silica-alumina, silica-magnesia, silica-zirconia, silica-tria, silica-beryllia, silica- Titania, and ternary compositions such as silica-alumina-tria, silica-alumina-zirconia, silica-alumina-magnesia and silica-magnesia-zirconia can be included. The latter can be naturally produced or can be in the form of a gelatinous precipitate or gel containing a mixture of silica and metal oxide. Naturally produced clays that can be combined with the catalyst include montmorillonite and kaolin family members. These clays can be used as produced from the original vein, or initially subjected to calcination, acid treatment or chemical modification.

  In carrying out hydrocracking and / or hydrotreating operations, one or more types of catalysts can be used in the reaction tower. Different types of catalysts can be separated into layers or mixed.

Hydrogenolysis conditions are explained fully in the literature. Generally, the total LHSV is from 0.1 / hour to 15.0 / hour (volume / volume), preferably from 0.25 / hour to 2.5 / hour. The reaction pressure is generally from 500 psig to 3500 psig (10.4 MPa to 24.2 MPa), preferably from 1500 psig to 5000 psig (3.5 MPa to 34.5 MPa). Hydrogen consumption is typically a 500～2500SFC / feed barrel (89.1~454m ³ H ₂ / ^{m 3} feed). The temperature in the reaction tower is 400 Fahrenheit to 950 Fahrenheit (205 ° C. to 510 ° C.), preferably 650 Fahrenheit to 850 Fahrenheit (340 ° C. to 455 ° C.).

  Typical hydroprocessing conditions vary within wide limits. Generally, the overall LHSV is from 0.5 to 5.0. The total pressure is 200 psig to 2000 psig. The hydrogen recycle rate is typically higher than 50 SFC / Bbl, preferably 1000 to 5000 SCF / Bbl. The temperature in the reaction tower is 400 to 800 degrees Fahrenheit (205 ° C. to 425 ° C.).

  “Hydroisomerization” is also simply referred to as “isomerization” and seeks to improve the cold flow properties of Fischer-Tropsch derived products by selectively adding branched chains in the molecular structure. It is an operation. In the present invention, isomerization can also be used for alcohol separation. Isomerization ideally achieves high conversion of normal paraffins to isoparaffins while simultaneously minimizing conversion by decomposition. The isomerization operation suitable for use in the present invention typically employs a catalyst that includes an acidic component and, optionally, an active metal component having hydrocracking activity. The acidic component of the catalyst preferably includes mesoporous SAPOs such as SAPO-11, SAPO-31, and SAPO-41, with SAPO-11 being particularly suitable. Intermediate pore zeolites such as ZSM-22, ZSM-23, SSZ-23, ZSM-35 and ZSM-48 can also be used to carry out the isomerization. Exemplary active metals include molybdenum, nickel, vanadium, cobalt, tungsten, aene, platinum and palladium. The metals platinum and palladium are particularly suitable as active metals and are used with platinum in most cases.

  As used herein, the term “intermediate pore size” refers to an effective pore opening in the range of 4.0 to 7.1 angstroms when the porous inorganic oxide is in a calcined form. Molecular sieves with pore openings in this range tend to have unique molecular sieve characteristics. Unlike small pore zeolites such as erionite and orthopyroxene, these allow hydrocarbons with some branched chains in the molecular sieve voids. Unlike large pore zeolites such as faujasite and mordenite, they can fractionate n-alkanes and slightly branched alkenes, and large alkanes having, for example, quaternary carbon atoms. . For example, reference may be made to US Pat. No. 5,413,695. The term “SAPO” refers to a silicoaluminophosphate molecular sieve as described, for example, in US Pat. Nos. 4,440,871 and 5,208,005.

When preparing a catalyst containing a non-zeolite molecular sieve and containing a hydrogenation component, a method of depositing metal on the catalyst using a non-aqueous method is usually preferred. Non-zeolite molecular sieves include [AlO ₂ and PO ₂ ] oxide units coordinated in a regular tetrahedron that can optionally include silica. Reference may be made to US Pat. No. 5,514,362. Catalysts containing non-zeolitic molecular sieves on which the metal is deposited using a non-aqueous process, especially those containing SAPOs, have greater selectivity compared to catalysts using the aqueous process for depositing active metals. And showed activity. Non-aqueous deposition of active metals on non-zeolitic molecular sieves is described in US Pat. No. 5,939,349. In general, this process involves the dissolution of the active metal compound in a non-aqueous, non-reactive solvent and its deposition on a molecular sieve by ion exchange or impregnation.

  Alcohol dehydration can be accomplished by treating the feed over a catalyst such as gamma alumina. During the dehydration period, the alcohol is converted to olefins. The dehydration of alcohols to olefins is described in Charles L.L. Chapter 5 of “Catalytic Processes and Proven Catalysts” by Thomas, “Dehydration”, Academic Press (1970). Another method is described in US Pat. No. 6,933,323, which is hereby incorporated by reference in its entirety.

  Another method for separating alcohol, also described in the examples of US Pat. No. 6,933,323, is to pass the concentrate through an adsorbent bed containing an adsorbent capable of adsorbing alcohol. Is included. Satisfactory adsorbents can include molecular sieves having a low silica to alumina ratio. Large pore molecular sieves having a low silica to alumina ratio, particularly molecular sieves characterized by having a FAU-type structure, are generally suitable for use as adsorbents for alcohol and other oxygen-containing materials. The preferred FAU molecular sieve is X zeolite, with 13X zeolite being particularly preferred. As used herein, the term “FAU molecular sieve” refers to the IZA Structure Commission standard that encompasses both X and Y zeolites.

  The synthesis of X-type zeolite is described in U.S. Pat. Nos. 2,882,244; 3,685,963; 5,370,879; 3,789,107 and 4,007. 253, which is incorporated herein by reference in its entirety. 13X zeolite is a faujasite (FAU) type X zeolite. It has a low silica / alumina ratio and is composed of silicon, aluminum and oxygen. The oxygen ring has a 7.4 Å void opening, but can adsorb molecules up to 10 Å. 13X zeolite has a Chemical Abstracts (CAS) number of [63231-69-6]. 13X zeolite is available from Aldrich Chemical Company and W.W. R. Commercially available from several sources, including Grace's Division Division. Furthermore, the method described in US Pat. No. 6,933,323 can be used here as described above.

  The flash point is the temperature that must be heated to produce enough fuel vapor to cause ignition on the surface of the liquid fuel when exposed to an open flame. The flash point is measured by ASTM D93 and is preferably at least 38 ° C.

The following example demonstrates the effect of inclusion of C ₁₁₊ alcohol in distillate fuel and the problem to be solved by realizing failure to meet diesel cloud point specifications.

  In this example, a 600 Fahrenheit (315 Fahrenheit) endpoint (according to ASTM D2887) Fischer-Tropsch diesel fuel with a high i / n ratio was prepared and tested.

Commercial samples of Fischer-Tropsch C ₈₀ wax were obtained from Moore and Munger Co. Obtained from It has an initial boiling point of 790 degrees Fahrenheit as measured by ASTM D2887 and a boiling point at 5% by weight of 856 degrees Fahrenheit. This was hydrocracked at 90% conversion in a single stage pilot plant by a single pass operation (no recycle) with 669 degrees Fahrenheit, 1.0 LHSV, 1000 psig, 10000 SCF / Bbl hydrogen. A commercial hydrogen sulfide addition cracking catalyst was used. A 260-600 ° F. product having the following properties was recovered by distillation. This product contains 2% by weight or more of n-C ₁₄₊ n-paraffins and has a cloud point of -51 ° C.

Density at 15 ° C., g / ml 0.7626
Sulfur, ppm 0
Viscosity at −20 ° C. cSt 6.382
Freezing point, ° C -47.7
Cloud point, ° C -51
Flash point, ° C 54
Smoke point, mm> 45

Hydrocarbon type, weight% by mass spectrum (ASTM D2789)
Paraffins 93.1
Mono-cycloparaffins 5.2
Di-cycloparaffins 1.5
Alkylbenzenes 0.1
Benzophenanthalene 0.0
Naphthalenes 0.1

Simulated distillation, Fahrenheit by weight%, ASTM D2887
0.5% 267
5% 287
10% 310
20% 342
30% 378
40% 405
50% 439
60% 472
70% 504
80% 535
90% 564
95% 579
99% 595
99.5% 598

  This sample was mixed with n-dodecanol in various amounts and the cloud point was measured. The original sample has a cloud point of −51 ° C., which meets the strictest cloud point specification in ASTM D975. However, the addition of only 0.1% by weight of oxygen as dodecanol significantly increased the cloud point.

  Additional diesel fuel samples were prepared at 675 Fahrenheit (375 ° C.) and 450 Fahrenheit (232 ° C.) endpoints and intermediate i / n ratios and tested as indicated below. This sample is no. Meets ASTM D975 endpoint and flashpoint requirements for 2-D fuels.

Fischer-Tropsch concentrate and wax samples were obtained from the cobalt catalyst. This concentrate was hydrotreated over a sulfurized commercial fully extruded non-acidic NiMo / Al ₂ O ₃ catalyst at 3.36 LHSV, 1000 osig total pressure, 5000 SCFB recycle gas rate. This wax is 1.2 LHSV, 66% below 675 degrees Fahrenheit (357 ° C.) / Pass conversion, 1000 psig total pressure, 5000 SCFB recycle gas rate over a sulfurized commercial fully extruded acidic NiW / Al ₂ O ₃ —SiO ₂ catalyst. Hydrogenolysis was performed. The products from the two devices were mixed continuously and then distilled. The product boiling above the diesel cut point (approximately 675 degrees Fahrenheit -357 ° C) was recycled to the light absorber in the hydrogenator.

The properties of 250-675 Fahrenheit (121-357 ° C.) diesel fuel are shown in the table below:

Detailed GC-MS analysis:

This diesel fuel was mixed with various primary linear alcohols and the cloud point was measured. The addition of 1-heptanol does not cause any _significant change in cloud point, but the addition of C ₁₁₊ alcohol increases the cloud point. These results, if C ₁₆₊ alcohol content is 0.3 wt% oxygen or higher as oxygenate, is not able to be achieved a cloud point of + 14 ° C.. Addition of 1-hexanol does not increase the cloud point exceptionally, but increases when 1-dodecanol is added. When C _{11 +} alcohol was present in admixture with 1-hexanol, in most cases, a marked increase in cloud point was still found. High levels of 1-hexadecanol and 1-eicosanol did not dissolve at ambient conditions (also at 50 ° C.). Therefore, the cloud point could not be measured. These are well above + 14 ° C.

混合アルコールは１−ヘキサノール、１−ドデカノール、１−ヘキサデカノールおよび１−エイコサノールの等重量パーセント混合物であった。

The mixed alcohol was an equal weight percent mixture of 1-hexanol, 1-dodecanol, 1-hexadecanol and 1-eicosanol.

  The diesel product from Example 2 was further distilled to obtain 250-400 degrees Fahrenheit (121-204 ° C.) diesel fuel fraction. This fraction is No. having these properties. This is a simulation of 1-D fuel.

These tests show that the addition of a small amount of dodecanol has a significantly detrimental effect on the cloud point. The addition of as little as 0.01 wt.% Oxygen as 1-dodecanol results in a cloud point well above the lowest cloud point of -49 ° C (measured by ASTM D2500, ° C). It is added to C ₅ -C ₁₀ alcohol, a significant increase in the cloud point was not obtained. As noted above, all weight percent oxygen concentrations are on a water-free basis.

A suitable FT diesel alcohol composition containing 1-C ₅ to 1-C ₁₀ is exemplified below.

Although this example cannot obtain a low cloud point with a normal alcohol such as 1-dodecanol, C ₅ -C ₁₀ normal alcohol can be used, especially with endpoints where the distillation fraction is lower than the conventional example and It has been shown that a low cloud point can be obtained when having an intermediate i / n ratio.

Claims (22)

It has a flash point of at least 38 ° C as measured by ASTM D93, a cloud point of + 14 ° C or lower, and 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol And at least two alcohols selected from the group consisting of a mixture of two or more alcohols in an amount not less than 0.01% by weight, and oxygen of C ₁₁₊ linear alcohol 0.01% Fischer-Tropsch derived distillate suitable for use as a diesel fuel containing in an amount not greater than% by weight.   The Fischer-Tropsch derived distillate according to claim 1, having a cloud point of 0 ° C.   The Fischer-Tropsch derived distillate according to claim 2, having a cloud point of -15 ° C or lower.   The Fischer-Tropsch derived distillate according to claim 3, having a cloud point of -25 ° C or lower.   The Fischer-Tropsch derived distillate according to claim 4, having a cloud point of -49 ° C or lower. Total oxygenate content of C ₅ -C ₁₀ linear alcohols present are within the range of 0.01 wt% of oxygen and 1 wt% oxygen, according to claim 1 Fischer - Tropsch derived distillate. A method for producing a Fischer-Tropsch derived distillate fuel, comprising:
(A) separating the Fischer-Tropsch concentrate into a first fraction and a second fraction;
(I) The first fraction contains 0.01 wt.% Of alcohol oxygen selected from the group consisting of 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol and mixtures thereof. And in a quantity that does not contain more than 0.01% by weight of oxygen of C ₁₁₊ linear alcohol, and (ii) the second fraction is C ₁₁₊ linear Contains alcohol;
(B) removing C ₁₁₊ linear alcohol from at least a portion of the second fraction and recovering the treated heavy fraction substantially free of C ₁₁₊ linear alcohol; then (c) step a (i ) At least a portion of the first fraction and a portion of the treated heavy fraction of step (b) in an appropriate ratio such that the total oxygen-feeding substance content of the C ₅ -C ₁₀ alcohol present is 0.01. Preparing a Fischer-Tropsch derived distillate fuel in the range of wt% oxygen to 1 wt% oxygen, having a cloud point no higher than + 14 ° C. and a flash point as measured by ASTM D93 of 38 ° C .;
A method involving that.   8. A process according to claim 7, wherein the first and second fractions are mixed in step (c) in suitable proportions to prepare a Fischer-Tropsch derived distillate fuel having a cloud point that is no higher than 0 <0> C.   9. A process according to claim 8, wherein the first fraction and the second fraction are mixed in a suitable proportion in step (c) to prepare a Fischer-Tropsch derived distillate fuel having a cloud point not higher than -15 [deg.] C. . The Fischer-Tropsch concentrate is separated into a first fraction, a second fraction and a third fraction, wherein the first fraction and the second fraction are as described above, and the third fraction is a C4 _- linear 8. A method according to claim 7, comprising alcohol. The second fraction is treated by a method selected from hydrotreating, hydrocracking, hydroisomerization, dehydration, adsorption, absorption, or a combination thereof, and is treated substantially free of C ₁₁₊ linear alcohol The method according to claim 7, wherein a heavy fraction is obtained. In distillate fuels with a cloud point of + 14 ° C. or lower, consisting of 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, and a mixture of two or more alcohols The amount of oxygen of at least two alcohols selected from the group is not less than 0.01% by weight and the amount of oxygen in the C ₁₁₊ linear alcohol is not more than 0.01% by weight Improvements included in.   The distillate fuel according to claim 12, wherein the cloud point is 0 ° C or lower.   The distillate fuel according to claim 13, wherein the cloud point is -15 ° C or lower. Total oxygenate content of _C 5 _{-C 10} linear alcohols present are within the range of 0.01 wt% of oxygen and 1 wt% oxygen, distillate fuel of claim 12. Alcohol is any two of C ₅ -C ₁₀ linear alcohols total concentration which is the oxygen of less than 1 wt%, diesel fuel according to claim 12. Alcohol is any two of C ₅ -C ₁₀ linear alcohols total concentration which is the oxygen of less than 1% by weight, according to claim 1 Fischer - Tropsch derived distillate. Alcohol is any two of C ₅ -C ₁₀ linear alcohols total concentration which is the oxygen of less than 1% by weight, according to claim 7 Fischer - Tropsch derived distillate. Alcohol 1 is _{C 5} and _C 6; _{C 5} and _{C 7;} is selected from the group consisting of or a _{C 6} and _{C 7,} according to claim 19 Fischer - Tropsch derived distillate. The first fraction further comprises C ₈ , C ₉ and C ₁₀ 1-alcohols, and step b removes C ₁₁₊ linear alcohol from at least a portion of the second fraction to substantially eliminate C ₁₁₊ linear alcohol. The treated heavy fraction that is not naturally contained, and step (c) mixes at least a portion of the first fraction of step a (i) with a portion of the treated heavy fraction of step (b). The method according to claim 7. C _8, C ₉ and C _10, and which further includes a 1-alcohol selected from the group consisting of the alcohol mixture, and paraffins is at least 90% i-paraffins, diesel according to claim 12 fuel. C _8, C ₉ and C _10, and which further includes a 1-alcohol selected from the group consisting of the alcohol mixture, paraffins is at least 90% i-paraffins, diesel fuel according to claim 1 .