Fuel comprising ketone(s)

Abstract

Provided are fuel components, a method for producing fuel components, use of the fuel components and fuel containing the fuel components based on ketone(s).

Claims

1. A diesel fuel consisting of: diesel fuel and 5-nonanone, wherein the content of the 5-nonanone in the fuel is 2.0 to 45.0 vol-%.

2. The diesel fuel according to claim 1, wherein the content of the 5-nonanone is 2.0-20.0 vol-%.

3. The diesel fuel according to claim 1, wherein the content of the 5-nonanone 2.0-15.0 vol-%.

4. A method of preparing a diesel fuel, the method consisting of: blending a diesel fuel with 5-nonanone, wherein the content of the 5-nonanone in the fuel is 2.0 to 45.0 vol-%.

5. A diesel fuel consisting of: diesel fuel, 5-nonanone, and a renewable fuel component, wherein the content of 5 nonanone in the fuel is 2.0 to 45.0 vol-%.

6. The diesel fuel according to claim 5, wherein the content of the 5 nonanone is 2.0-20.0 vol-%.

7. The diesel fuel according to claim 5, wherein the content of the 5 nonanone in the fuel is 2.0 to 15.0 vol-%.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) Generally, the present invention relates to a method for the production of ketone, specifically production of ketone from a renewable source, to the use of ketone as a fuel component as such and/or as a feed component for fuel production processes.

(2) In the following, a detailed description of the invention will be provided step-by-step.

(3) Method for Production of Ketone

(4) One aspect of the present invention relates to a method for the production of ketone(s), specifically to the production of a ketone compound or a mixture of ketones, and in particular the production of a ketone compound or a mixture of ketones from a renewable source, with high conversion (preferably more than 95 vol-%) and with high selectivity (preferably more than 95 vol-%).

(5) In a preferred aspect, the present invention relates to the method for the production of 5-nonanone, preferably from a renewable source. Levulinic acid (LA) is a suitable raw material which can be derived from renewable sources in large quantities in industrial scale.

(6) A schematic reaction route of producing 5-nonanone from LA, which may be employed in the method of the present invention, is as follows:

(7) ##STR00007##

(8) Other ketones may be derived from LA or other sources as well, e.g. via carboxylic acid intermediates having 2 to 6 carbon atoms.

(9) Methods for producing pentanoic acid (PA) and other carboxylic acids from LA or other sources with reasonable conversion are known in the art and any known method for producing the carboxylic acids may be employed in the present invention. In one embodiment, LA derived from a renewable source is subjected to hydrogenation to produce GVL. The GVL is subsequently or simultaneously converted to pentanoic acid by hydrogenation. Catalyst for use in the hydrogenation reaction is preferably a bi-functional catalyst, which contains acid-functionality (having for example zeolites, SAPO or IER as a catalyst component) and metal-functionality (having for example Pt or Pd as a catalyst component) so that ring-opening of GVL to pentenoic acid and hydrogenation of pentenoic acid to PA can proceed simultaneously.

(10) Any other reaction scheme may be employed to produce the carboxylic acid, such as pentanoic acid, preferably from a renewable source, for example hydroformylation of (bio)butene or oxidation of n-paraffin. Further, the reaction scheme is not limited to routes employing LA as a raw material, although this route is preferred in view of the availability of LA in large quantities.

(11) The prior art discloses several methods for producing ketones, e.g. methods for producing 5-nonanone from pentanoic acid. However, none of the prior art techniques achieves both high selectivity and high conversion. Specifically, the known methods for producing 5-nonanone achieve a selectivity of at most 90%, wherein the main residue is pentanoic acid (PA). This causes problems in the further procedure. Either, the PA must be separated using complicated methods or the PA leads to side reactions in the subsequent processing. Similar problems arise when converting other carboxylic acids or mixtures of carboxylic acids to ketones.

(12) The ketone production method of the present invention, however, employs a specific oxide catalyst comprising an alkali metal oxide and at least one further metal oxide which is different from the alkali metal oxide and achieves almost full conversion, such as more than 95 vol-% relative to all liquid reaction products, of the carboxylic acid to the ketone. Accordingly, there is no need for complicated separation techniques which improves the overall energy efficiency of the process.

(13) The oxide catalyst may be a mixed oxide, a solid solution oxide or a catalyst in which one metal oxide is supported on another metal oxide. The alkali metal oxide can be supported on at least one further metal oxide. The oxide catalyst may further be supported on a support other than a metal oxide.

(14) The alkali metal oxide may be K.sub.2O, which has shown to provide excellent conversion efficiency.

(15) The at least one further metal oxide may be selected from the group consisting of titania, silica, ceria, zirconia and γ-alumina, or mixtures, mixed oxides or solid solutions of these. The metal oxide may be ceria-zirconia mixed oxide, titania, or a mixture of alumina and titania. The at least one further metal oxide may comprise at least titania. It is particularly preferred that the oxide catalyst is K.sub.2O/TiO.sub.2 with which catalyst a good conversion has been achieved.

(16) The reaction may be carried out in a batch type reactor or in a continuous flow type reactor. The reaction temperature may be in the range 300° C. to 450° C., preferably in the range 360° C. to 390° C.

(17) The weight hourly space velocity WHSV may be in the range of 0.2 h.sup.−1 to 5.0 h.sup.−1 depending on the dimensioning of the process parameters. The pressure (absolute) may be in the range of 1.0 bar to 25.0 bar, for example 10 bar±2 bar or 20 bar±2 bar.

(18) The reaction may be carried out in the presence of a carrier gas such as nitrogen, hydrogen, carbon dioxide, water vapor (H.sub.2O) or methane, preferably H.sub.2, CO.sub.2 or H.sub.2O. These gases may be admixed into the reaction mixture and/or may be formed in the course of the reaction. The carrier gas may be used to expel gaseous or volatile reaction products from the product mixture such as H.sub.2O or CO.sub.2.

(19) Further, a solvent may be used in the reaction. The reaction does not require the presence of a solvent. If the reaction is carried out in the presence of a solvent, the content thereof is 50 vol-% or less. Further, it is preferable that no solvent is used.

(20) Although it is not desired to be bound to theory, the method of the present invention is generally referred to as a ketonisation reaction. The method of the present invention provides the benefit that a highly oxygen-deficient product, having an oxygen content of about 11% by weight in the case of 5-nonanone, can be produced from carboxylic acid, having an oxygen content of about 31% by weight in the case of PA, without the need of adding hydrogen gas. Accordingly, it is preferred that no hydrogen gas is added in the ketonisation reaction while forming ketone from carboxylic acid.

(21) The ketone(s) (ketone compound or mixture of ketones) can be processed further for example by hydrogenation or hydrodeoxygenation (HDO). The ketone(s) can also be used as a feed to a HDO and/or isomerization process. Specifically, the ketone production method of the present invention shows high selectivity and conversion so that the resulting ketone(s) can be employed in various applications and can be upgraded, processed further, using various methods, even if these methods do not tolerate large amounts of residues such as in particular unreacted acid residue.

(22) According to the method of the present invention, the ketone(s) is/are produced with high selectivity and conversion which eliminates the need for recycling or separation steps such as recycling or removing unreacted acids. In an embodiment a simple phase separation technique may be used with high efficiency. Specifically, 5-nonanone spontaneously separates from water, which allows such a simple phase separation. Further, it is possible that no separation other than removal of water and gaseous components is carried out. Separation of water as vapor is a further option which can be combined with any of the above options.

(23) Use of Ketone(s) as Fuel Component as Such and/or Fuel Containing Ketone(s)

(24) According to an aspect of the present invention, the ketone(s) is/are used as fuel component without further modification. For example, the ketone(s) may be blended with conventional fuel (fossil fuel or a mixture of fossil fuel and renewable fuel components other than the ketone) to obtain a fuel blend (or simply “fuel”). Further, the ketone(s) may be blended with renewable fuel components other than the ketone. Preferably, the ketone is produced using the ketone production method of the present invention.

(25) The prior art concentrated on ketones, specifically 5-nonanone, as an intermediate for producing fuel components, in which the ketones are then further processed e.g. by hydrogenation and subsequent condensation. The inventors of the present invention surprisingly found that ketone(s) may be used as a fuel component as such without further modification and still provide good fuel properties.

(26) Specifically, the inventors found that fuels (fuel blends), specifically diesel, jet and/or gasoline fuel (blends), containing ketone(s), such as 5-nonanone, remain homogeneous for very long time. Accordingly, ketone(s) can be used as a fuel component without phase separation of fuel over time. Further, the oxygen contained in ketone molecules can help improving the combustion process.

(27) In the present invention, ketone(s) is/are employed as a fuel component, preferably in admixture with conventional fuel (i.e. fossil fuel or a mixture of fossil fuel and renewable fuel) or in admixture with renewable fuel. It is thus preferable that the content of the ketone(s) in the fuel is 2.0 vol-% or more, 2.5 vol-% or more, 3.0 vol-% or more, 3.5 vol-% or more, 4.0 vol-% or more, 4.5 vol-% or more, 5.0 vol-% or more, 5.5 vol-% or more, 6.0 vol-% or more, 7.0 vol-% or more, 8.0 vol-% or more, or 10.0 vol-% or more.

(28) Good fuel properties are achieved even when a high amount of the ketone(s) is employed. Nevertheless, the content of the ketone(s) in the fuel should preferably be 50.0 vol-% or less, preferably 45.0 vol-% or less, 40.0 vol-% or less, 35.0 vol-% or less, 30.0 vol-% or less, 25.0 vol-% or less, 20.0 vol-% or less, 15.0 vol-% or less, or 12.0 vol-% or less.

(29) A particularly preferred content of the ketone in the fuel is in the range of 2.0 vol-% to 20.0 vol-%, especially 2.0-15.0 vol-%.

(30) The fuel according to an embodiment of the invention may comprise fossil fuel component(s) in addition to the ketone(s). The fossil fuel components, if present, may be contained in an amount of preferably 40.0 vol-% or more, 45.0 vol-% or more, 50.0 vol-% or more, or 55.0 vol-% or more.

(31) The fuel according to the invention may comprise renewable fuel component(s) in addition to the ketone(s) or in addition to the ketone(s) and fossil fuel component(s). The content of the renewable fuel component(s), such as hydrotreated vegetable oil (HVO) and ethanol, is preferably 1.0 vol-% or more, 2.0 vol-% or more, 4.0 vol-% or more, or 6.0 vol-% or more when used in combination with fossil fuel. Although the content of the renewable fuel component(s) is not necessarily limited, it is desirable that the content thereof is 15.0 vol-% or less, 12.0 vol-% or less, 10.0 vol-% or less, 8.0 vol-% or less, or 7.0 vol-% or less when used in combination with fossil fuel. The content of the renewable fuel component(s) may be selected depending on the desired properties of the final fuel such as cetane number and octane number. If no fossil fuel component is contained in the fuel of the invention, the fuel may (essentially) consist of the ketone(s) and the renewable fuel component(s).

(32) In the present invention, the fuel may consist of the ketone(s) and at least one of fossil fuel component(s) and renewable fuel component(s).

(33) The fuel of the present invention may further comprise hydrocarbon fuel components as a balance. That is, if the sum of components mentioned above is less than 100 vol-%, the remainder may be hydrocarbon fuel components. The hydrocarbon fuel components may be derived from any source, e.g. fossil source or renewable source. The hydrocarbon fuel components may be neat compounds such as one single hydrocarbon but are usually mixtures of hydrocarbons having specific boiling point ranges i.e. hydrocarbon fractions. The hydrocarbon fractions may be selected depending on the type of fuel to be produced.

(34) 5-nonanone, as a preferred example of the ketone, shows a bRON value, which means blending RON value, which is determined using a 10 vol-% blend in gasoline in accordance with the procedure disclosed in U.S. Pat. No. 4,244,704 A of about 63 which makes it suitable as a blend component in gasoline fuel blends. When employed in gasoline fuel blends, the content of ketone(s), such as 5-nonanone, is preferably 2.0 vol-% or more, 2.5 vol-% or more, 3.0 vol-% or more, 3.5 vol-% or more, 4.0 vol-% or more, 4.5 vol-% or more, 5.0 vol-% or more, 6.0 vol-% or more, 7.0 vol-% or more, or 8.0 vol-% or more. In gasoline fuel blends, the content of ketone(s), such as 5-nonanone, is preferably, 35.0 vol-% or less, 30.0 vol-% or less, 25.0 vol-% or less, 20.0 vol-% or less, 15.0 vol-% or less, or 12.0 vol-% or less. The remainder of the gasoline fuel blend may be hydrocarbon fuel components, renewable fuel and/or conventional fuel such as fossil fuel or a mixture of fossil fuel and other gasoline fuel components such as renewable fuel components.

(35) Most preferably, the ketone(s), such as 5-nonanone, is/are employed as a blending component in diesel fuel blends. 5-nonanone has a bCN, blending cetane number, determined using the same type of calculation procedure as for bRON, of about 55, which is a good level for e.g. EN590 fuel. Further, although neat 5-nonanone has a cloud point (CP) of only −6.8° C., the inventors of the present invention surprisingly found that e.g. a diesel fuel blend containing 10 vol-% 5-nonanone did not deteriorate the cloud point. The blend had good cold properties. Accordingly, the ketone(s), especially 5-nonanone, can also be used in winter grade diesel fuel blends. When employed in diesel fuel blends, the content of ketone(s), such as 5-nonanone, is preferably 2.0 vol-% or more, 2.5 vol-% or more, 3.0 vol-% or more, 3.5 vol-% or more, 4.0 vol-% or more, 4.5 vol-% or more, 5.0 vol-% or more, 6.0 vol-% or more, 7.0 vol-% or more, or 8.0 vol-% or more. In diesel fuel blends, the content of the ketone(s), such as 5-nonanone, is preferably 45.0 vol-% or less, 40 vol-% or less, 35.0 vol-% or less, 30.0 vol-% or less, 25.0 vol-% or less, 20.0 vol-% or less, 17.0 vol-% or less, 15.0 vol-% or less, 13.0 vol-% or less, or 12.0 vol-% or less. The remainder of the diesel fuel blend may be hydrocarbon fuel components, renewable fuel components and/or conventional fuel such as fossil fuel or a mixture of fossil fuel and other fuel components such as renewable fuel components.

(36) In the present invention, the relative contents of materials in a liquid mixture, blend, can be determined from the GC area in GC-MS analysis.

(37) One further aspect of the present invention relates to a method of preparing a fuel by blending renewable fuel or conventional fuel, e.g. fossil fuel or a mixture of fossil fuel and renewable fuel, with the ketone(s). The method preferably comprises blending the ketone(s) such that the fuel of the present invention is obtained. Preferably, the ketone(s) is/are blended with renewable or conventional fuel comprising no ketone according to formula (1) or comprising less than 1.0 vol-%, preferably less than 0.5 vol-% thereof. In other words, it is preferred that renewable or conventional fuel is blended with the ketone(s) and the amount of addition of the ketone(s) is the same as the “content” of the ketone(s) as recited above with respect to the fuel of the present invention.

(38) The present invention further relates to the use of the ketone(s) as a fuel component and to the use of the ketone(s) for preparing a fuel blend comprising the ketone(s) and other fuel components suitable to produce the fuel of the present invention.

EXAMPLES

(39) The present invention is further illustrated by way of Examples. However, it is to be noted that the invention is not intended to be limited to the exemplary embodiments presented in the Examples.

(40) In the Examples, the following measurement methods were used and it is preferred that these methods are used in accordance with the present invention:

(41) Density: ENIS012185:1996

(42) Cloud point: ASTM D7689:2012

(43) CFPP (cold filter plugging point): EN116:2015

(44) Cetane Number: EN15195:2014

(45) Lower heating value: ASTM D4809:2013

Example 1

(46) Pentanoic acid (PA) was prepared by hydrogenation of gamma-valerolactone (GVL) using a commercial bi-functional catalyst, which has acidic and metallic catalyst sites, in continuous run tests. Testrun conditions and GC results are presented in Table 1 below.

(47) TABLE-US-00001 TABLE 1 Process conditions Average product density and composition H2/oil by GC Testrun No Feed (fresh feed) WHSV Pentyl (days) GVL Temperature Pressure volume ratio (NTP) (organic feed) 1-pentanol GVL Pentanoic acid pentanoate Others Density wt-% ° C. bar vol/vol h.sup.−1 GC-area-% g/cm.sup.3 1 (3) 100 200 40 1100 1.0 0.9 93.3 2.7 0.1 2.9 1015.0 2 (4) 100 240 40 1100 1.0 1.8 73.4 21.7 2.1 1.1 993.0 3 (4) 100 280 40 1100 1.0 0.1 7.4 84.6 4.9 3.0 916.9 4 (4) 100 240 40 1100 0.5 0.9 71.2 24.6 1.9 1.4 991.6

(48) About 85% PA selectivity based on GC-area-% was observed in testrun No 3. PA is a valuable chemical intermediate and it can be converted to 5-nonanone via ketonization reaction.

(49) Comparable or even better conversion results can be expected when using other catalysts together with optimized reaction conditions.

Example 2

(50) Conversion of PA to 5-nonanone was explored by ketonization of PA over K.sub.2O/TiO.sub.2 catalyst in a continuous flow reactor system using nitrogen as carrier gas and reaction conditions: temperature 375° C., pressure 1 bar (absolute pressure) and WHSV 1 h.sup.−1. Water was separated after the product stream left the reactor.

(51) The content of 5-nonanone was about 98-99 GC-area-%. Further, no pentanoic acid was observed, indicating 100% conversion. Accordingly, no complicated separation of 5-nonanone from pentanoic acid was necessary. Based on GC analysis the sample consisted mainly of 5-nonanone and minor amounts of oxygen compounds (being named as “other” 1 to 5 in test results), like 1-butanol, pentanal, 2-hexanone, 4-octanone, 3-methyl-4-octanone and 4,4,5-trimethyl-2-cyclohexenone. The density of the organic product stream consisting essentially of 5-nonanone was 826-827 kg/m.sup.3.

(52) GC and density results of pentanoic acid ketonization are presented in Table 2.

(53) TABLE-US-00002 TABLE 2 Pentanoic 5- Testrun Density acid Nonanone Other 1 Other 2 Other 3 Other 4 Other 5 (days) kg/m3 area-% area-% area-% area-% area-% area-% area-% 1 826.2 0 98.2 1.1 0.1 0.2 0.2 0.2 2 825.8 0 98.4 1.0 0.1 0.2 0.2 0.1 3 825.8 0 98.6 0.9 0.1 0.2 0.1 0.1 4 825.6 0 98.9 0.6 0.1 0.2 0.1 0.1 5 825.7 0 98.8 0.8 0.1 0.1 0.1 0.1 6 825.6 0 98.7 0.9 0.1 0.1 0.1 0.1 7 826.7 0 98.1 1.3 0.2 0.2 0.2 0.2 8 825.7 0 98.8 0.8 0.1 0.1 0.1 0.1 9 825.7 0 98.8 0.8 0.1 0.1 0.1 0.1

Example 3

(54) Suitability of 5-nonanone as a traffic fuel component was studied. 5-nonanone was blended with both fossil diesel fuel and fossil oxygen-free gasoline fuel and critical properties of the blends were measured.

(55) It is known that 5-nonanone (CAS 502-56-7) has the following properties: boiling point 186° C., density 0.826 g/cm.sup.3, oxygen content 11.2 wt-%. In view of the boiling point value, 5-nonanone suits both fuels; diesel and gasoline. It may even be employed in jet fuel.

(56) Measured properties for the 90 vol-% fossil diesel+10 vol-% 5-nonanone blend are presented in table 3 below.

(57) TABLE-US-00003 TABLE 3 Cloud Lower Density point CFPP heating Tested blend (kg/m.sup.3) (° C.) (° C.) Cetane No value (MJ/l) Fossil diesel 818.4 −28.6 −31 47.5* 35.4 90% fossil diesel + 818.7 −29.3 −30 48.3* 34.9 10% 5-nonanone *on the above table means Cetane number achieved without using cetane improver.

(58) In the light of the test results ketone improved or did not substantially decrease the fuel blend properties. Specifically, the addition of 10 vol-% of 5-nonanone had good effect of the analyzed properties in diesel blend when compared to pure fossil diesel. That is, both cloud point and cetane number are improved by addition of the ketone. This is even more surprising when considering that neat 5-nonanone has a cloud point (CP) of only −6.8° C. Cold properties of the blend are in a good level. Oxygen content of the blend was calculated to be 1.1 wt.-%. Nevertheless, the heating value of the diesel blend (fossil diesel+5-nonanone) stayed close to the original level in spite of the addition of the oxygenate (5-nonanone). Conventionally, oxygen containing molecules were seen as energy content decreasing components.

(59) 5-nonanone has a bRON value of ca. 63 and it can be used also as a blend component in gasoline fuel blends. Measured properties for the 90 vol-% fossil oxygen-free gasoline+10 vol-% 5-nonanone blend are presented in table 4 below.

(60) TABLE-US-00004 TABLE 4 Density Lower heating value Tested blend (kg/m3) RON (MJ/l) Fossil oxygen-free gasoline 741.9 95.3 32.1 MJ/l 90% fossil oxygen-free gasoline + 752.5 92.1 32.1 MJ/l 10% 5-nonanone

(61) Oxygen content of the blend was 1.2 wt.-%. When 5-nonanone was blended with gasoline, although the ketone slightly decreased the RON, the heating value remained on the same level. Thus, 5-nonanone can also be used as a component of gasoline fuel.