KARVO ANNA (FI)
| RU2151169C1 | 2000-06-20 | |||
| US4244704A | 1981-01-13 |
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| CLAIMS 1. Use of ethanol and isopentanol in a gasoline composition to increase motor octane number (MON), comprising providing the gasoline composition with ethanol in an amount from 3 vol-% to 10 vol-% and isopentanol in an amount from 5 vol-% to 15 vol-% of the total volume of the gasoline composition. 2. The use according to claim 1 , wherein the ethanol and/or the isopentanol is/are at least partially obtained or derived from renewable sources. 3. The use according to claim 1 or 2, comprising providing the gasoline composition with ethanol in an amount from 5 vol-% to 10 vol-%, preferably from 5 vol-% to 7 vol-%, such as about 5 vol-%, of the total volume of the gasoline composition. 4. The use according to any one of the preceding claims, comprising providing the gasoline composition with isopentanol in an amount from 5 vol-% to 13 vol-%, preferably from 7 vol-% to 13 vol-% or from 10 vol-% to 13 vol-% of the total volume of the gasoline composition. 5. The use according to any one of the preceding claims, wherein the gasoline composition is provided with ethanol and isopentanol in such amounts that the vol- % amount of ethanol and the vol-% amount of isopentanol in the gasoline composition are equal or the vol-% amount of isopentanol is higher than the vol-% amount of ethanol, preferably in such amounts that the vol-% ratio of ethanol to isopentanol in the gasoline composition is within a range from 1 :1 to 1 :3, more preferably within a range from 1 :2 to 1 :3, such as 5:11 . 6. The use according to any one of the preceding claims, wherein the gasoline composition comprises essentially oxygen free base gasoline preferably in an amount from 75 vol-% to 92 vol-%, such as from 80 vol-% to 85 vol-%, of the gasoline composition, which essentially oxygen free base gasoline is a combination of hydrocarbons comprising paraffinic, aromatic and olefinic hydrocarbons having from 4 to 12, preferably from 4 to 9, carbon atoms. 7. The use according to any one of the preceding claims, wherein the gasoline composition comprises essentially oxygen free base gasoline at least 77 vol-%, at least 78 vol-%, at least 80 vol-% or at least 82 vol-%; and/or at most 90 vol-%, at most 88 vol-%, at most 87 vol-% or at most 85 vol-% of the total volume of the gasoline composition. 8. The use according to any one of the preceding claims, wherein the sum of the vol-% amounts of ethanol, isopentanol, and essentially oxygen free base gasoline in the gasoline composition is at least 95 vol-%, preferably at least 99 vol-% based on the total volume of the gasoline composition, more preferably the gasoline composition consists essentially of ethanol, isopentanol, and essentially oxygen free base gasoline. 9. The use according to any one of the preceding claims, wherein the gasoline composition has a motor octane number (MON) of at least 85, preferably at least 86. 10. Use of isopentanol in a gasoline composition containing ethanol and essentially oxygen free base gasoline to increase motor octane number (MON) and/or to adjust distillation behaviour, preferably to decrease the E70 value (vol-% evaporated at 70 °C), which essentially oxygen free base gasoline is a combination of hydrocarbons comprising paraffinic, aromatic and olefinic hydrocarbons having from 4 to 12, preferably from 4 to 9, carbon atoms, the use comprising providing isopentanol and ethanol in such amount that the gasoline composition contains isopentanol from 5 vol-% to 15 vol-% and ethanol from 3 vol-% to 10 vol-%. 11. A gasoline composition comprising, based on the total volume of the gasoline composition, ethanol from 3 vol-% to 10 vol-%, preferably from 5 vol-% to 10 vol-%, more preferably from 5 vol-% to 7 vol-%, such as about 5 vol-%, isopentanol from 5 vol-% to 15 vol-%, preferably from 5 vol-% to 13 vol-%, more preferably from 7 vol-% to 13 vol-% or from 10 vol-% to 13 vol-%, and essentially oxygen free base gasoline from 75 vol-% to 92 vol-%, preferably at least 77 vol-%, at least 78 vol-%, at least 80 vol-% or at least 82 vol-%, and/or preferably at most 90 vol-%, at most 88 vol-%, at most 87 vol-% or at most 85 vol- %, which essentially oxygen free base gasoline is a combination of hydrocarbons comprising paraffinic, aromatic and olefinic hydrocarbons having from 4 to 12, preferably from 4 to 9, carbon atoms. 12. The gasoline composition according to claim 11 , wherein the vol-% amount of ethanol and the vol-% amount of isopentanol in the gasoline composition are equal or the vol-% amount of isopentanol is higher than the vol-% amount of ethanol, preferably the vol-% ratio of ethanol to isopentanol in the gasoline composition is within a range from 1 :1 to 1 :3, more preferably within a range from 1 :2 to 1 :3, such as 5:11 . 13. The gasoline composition according to claim 11 or 12, wherein the sum of the vol-% amounts of ethanol, isopentanol, and essentially oxygen free base gasoline is at least 95 vol-%, preferably at least 99 vol-% based on the total volume of the gasoline composition, more preferably the gasoline composition consists essentially of ethanol, isopentanol, and essentially oxygen free base gasoline. 14. The gasoline composition according to any one of claims 11-13, wherein the gasoline composition has a motor octane number (MON) of at least 85, preferably at least 86, and/or an E70 value (vol-% evaporated at 70 °C) of at most 50 vol-%, preferably at most 45 vol-%, more preferably at most 40 vol-%, such as 30 vol-%. 15. A method of preparing a gasoline composition comprising: providing ethanol; providing isopentanol; providing essentially oxygen free base gasoline, which essentially oxygen free base gasoline is a combination of hydrocarbons comprising paraffinic, aromatic and olefinic hydrocarbons having from 4 to 12, preferably from 4 to 9, carbon atoms blending ethanol, isopentanol, and essentially oxygen free base gasoline in such amounts that a gasoline composition is formed, comprising, based on the total volume of the gasoline composition, ethanol from to 3 vol-% to 10 vol-%, preferably from 5 vol-% to 10 vol-%, more preferably from 5 vol-% to 7 vol-%, such as about 5 vol-%, isopentanol from 5 vol-% to 15 vol-%, preferably from 5 vol-% to 13 vol-%, more preferably from 7 vol-% to 13 vol-% or from 10 vol-% to 13 vol-%, and essentially oxygen free base gasoline from 75 vol-% to 92 vol-%, preferably at least 77 vol-%, at least 78 vol-%, at least 80 vol-%, or at least 82 vol-%, and/or preferably at most 90 vol-%, at most 88 vol-%, at most 87 vol-% or at most 85 vol- %, wherein the formed gasoline composition has a motor octane number (MON) of at least 85 and/or an E70 value (vol-% evaporated at 70 °C) of at most 50 vol-%. |
TECHNICAL FIELD
The present disclosure generally relates to gasoline compositions and use of gasoline components. The disclosure relates particularly, though not exclusively, to use of ethanol and isopentanol in gasoline compositions and gasoline compositions comprising ethanol and isopentanol.
BACKGROUND
This section illustrates useful background information without admission of any technique described herein representative of the state of the art.
Gasoline, also referred to as petrol, is typically a mostly petroleum-derived liquid, primarily used as road transport fuel in vehicles having a spark ignition internal combustion engine. Gasoline consists mostly of organic compounds, including hydrocarbons, which have generally been obtained by fractional distillation of naturally occurring petroleum or crude oil and further refining. The demand for sustainable alternative gasoline or gasoline components is constantly growing due to ambitious CO 2 reduction targets set for example in the European Union. The growth in demand of sustainable alternative gasoline or gasoline components is seen globally. However, inclusion of renewable or recycled components should not alter or deteriorate the quality of gasoline.
Presently, ethanol is the most frequently used renewable (bio-based) component in gasoline. However, the ethanol content in gasoline compositions is often limited by automotive gasoline standards, and in some areas even by legislation, such as Directive 2009/30/EC. There is thus a need to increase the quantity of renewable components in gasoline compositions without compromising quality, and/or to improve quality of gasoline compositions with renewable content. SUMMARY
It is an aim to solve or alleviate at least some of the problems related to prior art. An object of the present invention is to provide quality improving use of ethanol and isopentanol in a gasoline composition. In particular, an aim is to provide use improving motor octane number (MON) and/or providing balanced and more predictable distillation behaviour.
The appended claims define the scope of protection.
According to a first example aspect there is provided use of or a method of using ethanol and isopentanol in a gasoline composition to increase motor octane number (MON).
The combination of ethanol and isopentanol was found to have a synergistic effect causing an unexpected improvement of MON. Surprisingly, using ethanol and isopentanol together or in combination in a gasoline composition increases the MON of the gasoline composition more than expected (predicted) based on calculations.
In certain embodiments, the ethanol and the isopentanol are renewable. It is a further aim to increase the content of renewable components in gasoline composition while preferably providing gasoline composition compatible with automotive gasoline standard, e.g. standard EN 228:2012, Amended 2017. As ethanol and isopentanol may both be derived from renewable (biological) feedstock, a further advantage of using ethanol and isopentanol in combination in a gasoline composition is that the content of renewable components (bio-content) in the gasoline composition may be increased, compared for example to conventional E10 gasoline, while preferably complying with automotive gasoline standard, such as EN 228:2012, Amended 2017.
According to a second example aspect there is provided use of isopentanol in a gasoline composition containing ethanol and essentially oxygen free base gasoline to increase motor octane number (MON) and/or to adjust distillation behaviour, preferably to decrease the E70 value (vol-% evaporated at 70 °C at standard atmospheric pressure), which essentially oxygen free base gasoline is a combination of hydrocarbons comprising paraffinic, aromatic and olefinic hydrocarbons having from 4 to 12, preferably from 4 to 9, carbon atoms. It was found that isopentanol may be used to improve predictability of distillation behaviourof gasoline compositions containing ethanol and base gasoline. Typically, distillation curves of gasoline compositions of ethanol and base gasoline have a shape that deviates from the roughly linear shape with a steady, upward slope typically seen for gasoline compositions consisting of hydrocarbons between 10 % and 90 % evaporated temperatures. As said deviation is typically observed as a local decrease of the (upward) slope of the distillation curve generally coinciding with a distillation temperature of 70 °C, smoothening or decreasing this deviation by inclusion of isopentanol in the gasoline composition decreases the E70 value of the gasoline composition compared to gasoline composition of ethanol and base gasoline. In practice, this provides improved predictability of the E70 value for the gasoline composition thus facilitating the preparation of gasoline compositions especially by blending gasoline components.
According to a third example aspect, there is provided a gasoline composition comprising, based on the total volume of the gasoline composition, ethanol from 3 vol-% to 10 vol-%, preferably from 5 vol-% to 10 vol-%, more preferably from 5 vol-% to 7 vol-%, such as about 5 vol-%, isopentanol from 5 vol-% to 15 vol-%, preferably from 5 vol-% to 13 vol-%, more preferably from 7 vol-% to 13 vol-% or from 10 vol-% to 13 vol-%, and essentially oxygen free base gasoline from 75 vol-% to 92 vol-%, preferably at least 77 vol-%, at least 78 vol-%, at least 80 vol-% or at least 82 vol-%, and/or preferably at most 90 vol-%, at most 88 vol-%, at most 87 vol-% or at most 85 vol- %, which base gasoline is a combination of hydrocarbons comprising paraffinic, aromatic and olefinic hydrocarbons having from 4 to 12, preferably from 4 to 9, carbon atoms.
A method of preparing the gasoline composition of the third example aspect is also provided. Accordingly, there is provided a method of preparing a gasoline composition comprising: providing ethanol; providing isopentanol; providing essentially oxygen free base gasoline, which base gasoline is a combination of hydrocarbons comprising paraffinic, aromatic and olefinic hydrocarbons having from 4 to 12, preferably from 4 to 9, carbon atoms; blending ethanol, isopentanol, and base gasoline in such amounts that a gasoline composition comprising, based on the total volume of the gasoline composition, ethanol from to 3 vol-% to 10 vol-%, preferably from 5 vol-% to 10 vol-%, more preferably from 5 vol-% to 7 vol-%, such as about 5 vol-%, isopentanol from 5 vol-% to 15 vol-%, preferably from 5 vol-% to 13 vol-%, more preferably from 7 vol-% to 13 vol-% or from 10 vol-% to 13 vol-%, and base gasoline from 75 vol-% to 92 vol-%, preferably at least 77 vol-%, at least 78 vol-%, at least 80 vol-%, or at least 82 vol-%, and/or preferably at most 90 vol- %, at most 88 vol-%, at most 87 vol-% or at most 85 vol-% is formed.
BRIEF DESCRIPTION OF THE FIGURES Some example embodiments will be described with reference to the accompanying figures, in which:
Fig. 1 shows distillations curves of BOB, E25, A0, A2, and A3.
DETAILED DESCRIPTION
All standards referred to herein are the latest revisions available, unless otherwise mentioned.
Vol-% refers in the context of this disclosure to vol-% based on the total volume of the gasoline composition, unless otherwise mentioned.
MON refers in the context of this disclosure to motor octane number. Preferable, the MON is determined according to EN ISO 5163:2014 and the reported MON value is the measured value minus 0.2.
RON refers herein to research octane number. Preferable, the RON is determined according to EN ISO 5164:2014 and the reported RON value is the measured value minus 0.2. E70 refers in the context of this disclosure to the percentage (vol-%) of a gasoline sample that evaporates at 70 °C at standard atmospheric pressure, preferably determined according to EN ISO 3405:2011 .
E100 refers herein to the percentage (vol-%) of a gasoline sample that evaporates at 100 °C at standard atmospheric pressure, preferably determined according to EN ISO 3405:2011.
E150 refers herein to the percentage (vol-%) of a gasoline sample that evaporates at 150 °C at standard atmospheric pressure, preferably determined according to EN ISO 3405:2011.
As used herein, base gasoline refers to a combination of hydrocarbons comprising paraffinic, aromatic and olefinic hydrocarbons having from 4 to 12, preferably from 4 to 9, carbon atoms. The term paraffinic hydrocarbons refers in the context of this disclosure to normal paraffins, isoparaffins, and/or cycloparaffins (naphthenes). Preferably, in the context of the present disclosure, the hydrocarbons making up the base gasoline have from 4 to 12, preferably from 4 to 9, carbon atoms. Preferably, the base gasoline is in the context of the present disclosure essentially oxygen free, i.e. essentially without oxygen content. The base gasoline may thus be considered as a blend stock for oxygenate blending. Further preferably, the base gasoline of the present disclosure has a boiling range within a temperature range from about 30 °C to about 230 °C, preferably within a range from about 30 °C to about 210 °C, preferably as determined according to EN ISO 3405:2011 . The base gasoline may for example be obtained as a distillation cut originating from crude oil optionally after further refining or through blending of different gasoline components, such as or including distillation cuts from crude oil optionally after further refining.
By way of example, the base gasoline of the present disclosure may be an essentially oxygen free combination of hydrocarbons having from 4 to 9 carbon atoms, which base gasoline may comprise, based on the total volume of the base gasoline, olefinic hydrocarbons from about 8 vol-% to about 30 vol-%, e.g. from about 12 vol-% to about 25 vol-%, and aromatic hydrocarbons from about 25 vol-% to about 50 vol%, e.g. from about 30 vol-% to about 45 vol-%, the remainder of the base gasoline being paraffinic hydrocarbons. However, base gasoline that can be used in the context of this disclosure is not limited hereto.
Methods for characterising a hydrocarbon composition by hydrocarbon type (paraffinic (alkanes), naphthenic (cyclo-alkanes), olefinic (alkenes) and aromatic) and carbon number are known in the field and may be performed for example according to EN ISO 22854 or by other gas chromatography-based detailed hydrocarbon analysis.
Isopentanol (i-pentanol) refers in the context of this disclosure to branched alcohols having five carbon atoms and one hydroxyl (-OH) group per molecule, the rest of the atoms in the molecule being hydrogen atoms. Preferably, the isopentanol is in the context of the present disclosure 3-methyl-1 -butanol. The isopentanol may be derived from fossil sources and/or renewable (biological) sources. Isopentanol is commercially available mostly as a synthetic variety, produced using fossil hydrocarbons as starting material, and hence as a non-renewable component. Methods for obtaining renewable isopentanol are however known in the field. Renewable isopentanol may be derived from biomass, including residual biomass. For example, renewable isopentanol may be produced through fermentation of biomass rich in carbohydrates, such as plants, plant parts or derivatives thereof, through acid hydrolysis of biomass, such as lignocellulosic biomass, and/or through catalytic conversion of for example cellulosic biomass.
Also the ethanol of the present disclosure may be derived from renewable and/or fossil sources. Methods for deriving ethanol from renewable sources and methods for deriving ethanol from fossil sources are known in the field. Renewable ethanol may be derived from biomass, including residual biomass. Ethanol has been commercially available as a renewable component for decades. Renewable ethanol may for example be produced through fermentation of biomass rich in carbohydrates, such as plants, plant parts or derivatives thereof, through acid hydrolysis of biomass, such as lignocellulosic biomass, and/or via gasification of biomass. Non-renewable (fossil) ethanol may be obtained for example through acid- catalysed hydration of ethylene, or CO2 reduction by hydrogen, the ethylene and CO2 originating or being derived from distillation cuts of crude oil or natural gas. In certain preferred embodiments, the ethanol and/or the isopentanol is/are at least partially obtained or derived from renewable sources (renewable feedstock). More preferably, the ethanol is renewable ethanol and/or the isopentanol is renewable isopentanol. Renewable ethanol and/or renewable isopentanol are beneficial in that they are more environmentally sustainable than their fossil counterparts. By providing or using renewable ethanol and/or renewable isopentanol, the content of renewable components in the gasoline composition may be increased compared e.g. to gasoline compositions of fossil gasoline components. The content of renewable components in the gasoline composition is increased particularly if both isopentanol and ethanol are of renewable origin.
As used herein, the term fossil refers to non-renewable components, and non renewable energy in contrast to renewable counterparts. Said renewable and fossil components are considered differing from one another based on their origin and impact on environmental issues. Therefore, they are treated differently under legislation and regulatory framework.
The renewable content may be determined both from neat gasoline components, such as neat ethanol or neat isopentanol, and from gasoline compositions by isotopic distribution involving 14 C, 13 C and/or 12 C as described for example in ASTM D6866:2018.
With respect to the term renewable in the context of a renewable gasoline component, this term refers to one or more organic compounds derived from any renewable (biological) source (i.e. not from any fossil based source) and suitable for use as gasoline component. Such component is characterised by mandatorily having a higher content of 14 C isotopes than similar components derived from fossil sources. Said higher content of 14 C isotopes is an inherent feature characterising the renewable gasoline component and distinguishing it from fossil gasoline components.
Thus, in gasoline compositions wherein the compositions are based on partly fossil based material and partly renewable gasoline component(s), the renewable component can be determined by measuring the 14 C activity. Analysis of 14 C (also referred to as carbon dating or radiocarbon analysis) is an established approach to determine the age of artefacts based on the rate of decay of the isotope 14 C, as compared to 12 C. This method may be used for determining the physical percentage fraction of renewable materials in bio/fossil mixtures as renewable material is far less aged than fossil material and so the types of material contain very different ratios of 14 C: 12 C. Thus, a particular ratio of said isotopes can be used as a “tag” to identify a renewable carbon compound and differentiate it from non-renewable carbon compounds. While the renewable component reflects the modern atmospheric 14 C activity, very little 14 C is present in fossil material (oil, coal). Therefore, the renewable fraction of a gasoline composition or gasoline component is proportional to its 14 C content. Samples of gasoline compositions may be analysed to determine the amount of renewable-sourced carbon in the gasoline composition. This approach would work equally for co-processed gasolines or gasolines produced from mixed feedstocks. It is to be noted that there is not necessarily any need to test input materials or blending components when using this approach as renewable content of the gasoline composition may be directly measured. The isotope ratio does not change in the course of chemical reactions. Therefore, the isotope ratio can be used for identifying renewable organic compounds and renewable gasoline components, and distinguishing them from non-renewable, fossil materials.
Biological material has about 100 wt-% renewable (i.e. contemporary or biobased or biogenic) carbon, 14 C, content which may be determined using radiocarbon analysis by the isotopic distribution involving 14 C, 13 C and/or 12 C as described for example in ASTM D6866 (2018). Other examples of a suitable method for analysing the content of carbon from biological or renewable origin are DIN 51637 (2014) or EN 16640 (2017).
For the purpose of the present disclosure, a carbon-containing material, such as an organic compound, is considered to be renewable or derived from renewable sources if it contains 90 % or more modern carbon (pMC), such as 100 % modern carbon, preferably as determined according to ASTM D6866. Accordingly, renewable ethanol has biogenic carbon content of 90 % or more, such as 100 %, preferably as measured according to ASTM D6866, and renewable isopentanol has biogenic carbon content of 90 % or more, such as 100 %, preferably as measured according to ASTM D6866.
Octane rating of a gasoline composition illustrates its antiknocking tendency in spark-ignition internal combustion engines. The antiknocking tendency indicates the capability of a gasoline composition to withstand compression without igniting. A gasoline composition with a higher octane rating is less prone to ignite under high pressure, i.e. without a spark, than a gasoline composition having a lower octane rating. In other words, the higher the octane rating, the higher is the knocking resistance of a gasoline composition. An increase in octane rating is therefore considered advantageous. Gasoline composition fed to a spark-ignition internal combustion engine is intended to be ignited at a rather precise place within the engine and only by the spark plug or a flame front ignited by the spark plug. Knocking occurs when a portion of the fed gasoline composition is not ignited by the spark plug or flame front ignited by the spark plug, but instead a portion of the gasoline composition ignites outside the envelope of the normal combustion front (this phenomenon is sometimes referred to as preignition). Controlled ignition of the gasoline composition is important for proper functioning of the engine. Preignition of the gasoline composition may even break the engine. A high octane rating is typically required for a gasoline composition to be suitable for use in high- performance spark-ignition internal combustion engines as in such engines a high pressure is often exerted on the fuel.
RON and MON are independent parameters describing antiknocking tendency of a gasoline composition. Although both RON and MON are determined using a cooperative fuel research (CFR) engine, the conditions during RON and MON determination are different. It is well known in the field that for a certain gasoline composition, the RON and the MON are different and have different numerical values. The difference in the numerical values of the RON and the MON is sometimes referred to as octane sensitivity. Determination of RON and MON is as such known in the field and RON and MON may be determined for example according to EN ISO 5164:2014 and EN ISO 5163:2014, respectively. Typically gasoline standards, such as standards for automotive gasoline, e.g. European standard EN228:2012, Amended 2017, set lower limits for RON and MON respectively. Accordingly, for a gasoline to be placed on the market e.g. as an automotive gasoline it should (inter alia) meet or exceed the minimum RON and the minimum MON set by the relevant standard.
MON is determined at high engine speed (900rpm) and variable ignition timing. The conditions at which MON is determined are more severe than the conditions at which RON is determined. Due to the differences between MON and RON, disclosing MON and RON values individually may be considered advantageous compared to for example merely indicating an antiknocking index (AKI) for a fuel. By merely indicating an antiknocking index it is impossible to assess the MON and the RON, thus making it more difficult to assess the performance of a gasoline composition. The AKI merely gives an arithmetic mean of MON and RON, but provides no details on the actual MON and RON values behind the AKI. Even though there may be some interrelation, one of RON and MON cannot predict the other and they can even be counterproductive.
The present inventors have surprisingly found that ethanol and isopentanol, when used together, can be used to increase motor octane number (MON) of a gasoline composition. The use of both ethanol and isopentanol in a gasoline composition was found to provide a synergistic effect causing an increase in the MON. By using ethanol and isopentanol together (in combination), the MON value of the gasoline composition is higher than predicted MON based on linear calculations based on vol-% of the components in the gasoline composition. This effect is not obtained by neither ethanol nor isopentanol alone. In certain embodiments, there is thus provided use of ethanol and isopentanol to form a gasoline composition having a MON, preferably as determined according to EN ISO 5163:2014, that is higher than a predicted MON of the gasoline composition based on linear calculation, preferably as calculated according to formula 4 (wherein pentanol is isopentanol). Formula 4 is shown in the Examples. The use described herein may include selecting components, optionally analysis thereof, addition of components by volume optionally in an order, and blending to obtain the gasoline composition.
In certain embodiments, the gasoline composition is provided with ethanol in an amount within the range from 3 vol-% to 10 vol-% and isopentanol in an amount within the range from 5 vol-% to 15 vol-% of the total volume of the gasoline composition. Such amounts of ethanol and isopentanol provides the gasoline composition with surprisingly good MON, and also comply with limits set for content of certain oxygenates in standard EN 228:2012, Amended 2017 (Table 1 ) and in Directive 2009/30/EC (Annex 1 ).
Preferably, amounts of ethanol and isopentanol provided are selected (from the herein mentioned ranges) so that the oxygen content of the gasoline composition is at most 3.7 wt-% based on the total weight of the gasoline composition. A high oxygen content may cause changes in combustion conditions in an engine when gasoline composition is used as a fuel, and such changes may affect operation of the engine. Gasoline compositions containing at most 3.7 wt-% oxygen also comply with the oxygen content requirement set in Directive 2009/30/EC (Annex 1 ), and the oxygen content requirement of standard EN 228:2012, Amended 2017 (Table 1). In certain embodiments, the oxygen content of the gasoline composition originates essentially in full from the ethanol and the isopentanol contained in the gasoline composition.
In certain preferred embodiments, the gasoline composition is provided with ethanol in an amount from 5 vol-% to 10 vol-%, preferably from 5 vol-% to 7 vol-%, such as about 5 vol-% of the gasoline composition and/or with isopentanol in an amount from 5 vol-% to 13 vol-%, preferably from 7 vol-% to 13 vol-%, such as from 7 vol-% to 11 vol-% or from 10 vol-% to 13 vol-%, such as from 11 vol-% to 13 vol-%, of the gasoline composition. Providing such amounts of ethanol and isopentanol achieves a surprisingly good MON, for example as shown by the Examples.
The gasoline composition comprises preferably an essentially oxygen free base gasoline. An advantage of the increase in MON is that essentially oxygen free base gasoline having a substandard MON (but possibly otherwise meeting the requirements of the relevant standard) may be blended with isopentanol and ethanol to form a gasoline composition having a MON that meets or exceeds the minimum MON set by the relevant standard (the gasoline composition thus possibly meeting all requirement of the relevant standard). The use may thus comprise blending ethanol and isopentanol with essentially oxygen free base gasoline (and optionally other gasoline components and/or additives). The ethanol, the isopentanol, and said base gasoline may be blended with each other in any order. Ethanol and isopentanol may be provided as separate components, or they may be provided as a two component blend that is then blended with the essentially oxygen free base gasoline.
Accordingly, in certain preferred embodiments there is provided use of ethanol and isopentanol to form a gasoline composition with essentially oxygen free base gasoline, which gasoline composition has an increased MON compared to the MON of the essentially oxygen free base gasoline. Such use preferably comprises combining (blending) isopentanol, ethanol and essentially oxygen free base gasoline to form a gasoline composition having an increased MON compared to the MON of said base gasoline. In certain particularly preferred embodiments, there is provided use of ethanol and isopentanol comprising blending isopentanol, ethanol and essentially oxygen free base gasoline to form a gasoline composition having a MON, preferably as determined according to EN ISO 5163:2014, that is higher than a predicted MON of the gasoline composition based on linear calculation, preferably as calculated according to formula 4 (wherein pentanol is isopentanol). Formula 4 is shown in the Examples. This synergistic effect of ethanol and isopentanol wherein the MON exceeds predicted MON cannot be obtained with only one of ethanol and isopentanol, but presence of both is required.
In the embodiments wherein the gasoline composition contains essentially oxygen free base gasoline, said base gasoline is the predominant gasoline component, in other words, it is the component of the greatest volume. The amount of the essentially oxygen free base gasoline in the gasoline composition is preferably from 75 vol-% to 92 vol-% based on the total volume of the gasoline composition. Essentially oxygen free base gasoline is beneficial in that it does not increase or contribute to the oxygen content of the gasoline composition.
In certain embodiments, the amount of essentially oxygen free base gasoline in the gasoline composition is at least 77 vol-%, at least 78 vol-%, at least 80 vol-% or at least 82 vol-%; and/or at most 90 vol-%, at most 88 vol-%, at most 87 vol-% or at most 85 vol-% of the gasoline composition. For example, the amount of essentially oxygen free base gasoline in the gasoline composition may be from 80 vol-% to 85 vol-%. The amount of essentially oxygen free base gasoline in the gasoline composition is such that the sum of the respective vol-% amounts of ethanol, isopentanol, and essentially oxygen free base gasoline in the gasoline composition is 100 vol-% or less. The sum of the vol-% amounts of ethanol, isopentanol, and essentially oxygen free base gasoline in the gasoline composition is preferably at least 95 vol-%, more preferably at least 99 vol-%, and even more preferably the gasoline composition consists essentially of ethanol, isopentanol, and essentially oxygen free base gasoline. Such gasoline compositions are particularly suitable as fuels for spark- ignition internal combustion engines and have a high MON. In addition to ethanol, isopentanol, and essentially oxygen free base gasoline, the gasoline composition may comprise for example gasoline additives. In certain particularly preferred embodiments, isopentanol, ethanol and the essentially oxygen free base gasoline are the components of the gasoline composition, and no further components are present.
The gasoline composition of the present disclosure has preferably a motor octane number (MON) of at least 85, more preferably at least 86. Although a MON of 81 may in certain circumstances be considered sufficient, a MON of at least 85 or at least 86 is advantageous in that it complies with the MON requirement set in Directive 2009/30/EC (Annex 1 ). It also complies with the MON requirement of EN 228:2012, Amended 2017 (Table 1 ). A MON of at least 85, even at least 86, may be achieved by the herein described use of isopentanol and ethanol in combination without further octane improvers, for example as shown by the Examples.
The ethanol and the isopentanol may be provided in such amounts that in the gasoline composition the respective vol-% amounts of ethanol and isopentanol are equal. Preferably, the vol-% amount of isopentanol is higher than the vol-% amount of ethanol in the gasoline composition. The present inventors have surprisingly found that, although ethanol has a higher bMON than isopentanol, providing ethanol and isopentanol in such amounts that the vol-% amount of isopentanol is higher than the vol-% amount of ethanol in the gasoline composition achieves a particularly high MON. As illustrated by the Examples, the MON of gasoline compositions wherein the vol-% amount of isopentanol is higher than the vol-% amount of ethanol may be higher than MON of similar gasoline compositions containing a higher vol- % of ethanol and/or containing isopentanol in a vol-% amount that is equal to the vol-% amount of ethanol in the gasoline composition. In certain preferred embodiments, the vol-% ratio of ethanol to isopentanol in the gasoline composition is within a range from 1 :1 to 1 :3, more preferably within a range from 1 :2 to 1 :3, such as 5:11 .
Gasoline compositions of ethanol and base gasoline are known to behave unpredictably upon distillation. As a pure compound, ethanol exhibits straightforward distillation behaviour, but when added to a base gasoline, the distillation behaviour of the mixture is anything but straightforward. Distillation characteristics directly affect vehicle performance, such as starting, driveability, fuel economy, and balanced distillation characteristics in gasoline ensure or improve driveability. To ensure proper vehicle operation, the distillation behaviour of gasoline compositions is typically regulated. For example, standard EN 228:2012, Amended 2017, sets limits for vol-% evaporated at 70 °C, 100 °C, and 150 °C at standard atmospheric pressure.
As ethanol may cause, due to its azeotropic behaviour, a decrease in the (upward) slope of the distillation curve of gasoline composition around the E70 point, especially the E70 value of gasoline compositions containing ethanol and base gasoline is difficult to predict. Difficulty to predict the E70 value may lead to some blends, despite careful design of the blends, to be substandard, i.e. unsuitable to be sold as automotive gasoline. Such substandard blends may at worst not find any value added use.
Distillation curves of gasoline compositions consisting of hydrocarbons typically have a smooth and steady upward slope between the 10 % and 90 % evaporated temperatures. Such steady slope provides good predictability of the distillation behaviour, including good predictability of the E70 value.
The inventors surprisingly found that a further advantage of using both ethanol and isopentanol together (in combination) in a gasoline composition containing essentially oxygen free base gasoline is that the distillation behaviour is more predictable compared to distillation behaviour of gasoline compositions of ethanol and essentially oxygen free base gasoline. Accordingly, in addition to increase MON, isopentanol and ethanol may be used together as described above to adjust distillation behaviour, preferably to decrease the E70 value (of the gasoline composition), i.e. vol-% evaporated at 70 °C at standard atmospheric pressure. In other words, including isopentanol in gasoline compositions containing ethanol and essentially oxygen free base gasoline yields a distillation curve that resembles more the distillation curve of gasoline compositions consisting of hydrocarbons. Accordingly, reducing the deviation from a steady, upward distillation curve slope by inclusion of isopentanol enables more reliable production of on-standard gasoline compositions. In practise, inclusion of isopentanol leads in the case of gasoline composition containing ethanol and base gasoline to a decrease in the E70 value. The predictability of the distillation behaviour is particularly improved when ethanol and isopentanol are provided in such amounts that the vol-% amount of isopentanol is higher than the vol-% amount of ethanol in the gasoline composition.
Thus, the present disclosure provides use of isopentanol and ethanol (together) in a gasoline composition comprising essentially oxygen free base gasoline or use of isopentanol in a gasoline composition containing ethanol and essentially oxygen free base gasoline to adjust distillation behaviour (of the gasoline composition), preferably to decrease the E70 value (of the gasoline composition), and/or to increase MON (of the gasoline composition). Preferably, the use comprises providing isopentanol and optionally ethanol in such amount(s) that the gasoline composition contains isopentanol from 5 vol-% to 15 vol-%, more preferably from 5 vol-% to 13 vol-%, even more preferably from 7 vol-% to 13 vol-% or from 10 vol-% to 13 vol-%, such as from 11 vol-% to 13 vol-%, ethanol from 3 vol-% to 10 vol-%, preferably from 5 vol-% to 10 vol-%, more preferably from 5 vol-% to 7 vol-%, such as about 5 vol-%, and essentially oxygen free base gasoline from 75 vol-% to 92 vol-%, preferably at least 77 vol-%, at least 78 vol-%, at least 80 vol-% or at least 82 vol-%, and/or preferably at most 90 vol-%, at most 88 vol-%, at most 87 vol-% or at most 85 vol-%. The ethanol may be provided as a gasoline component to be blended with isopentanol and base gasoline (in any order), or isopentanol may be included in a gasoline composition already containing ethanol (and essentially oxygen free base gasoline). Advantageously, the sum of the vol-% amounts of ethanol, isopentanol, and essentially oxygen free base gasoline in the gasoline composition is at least 95 vol-%, preferably at least 99 vol-%, more preferably the gasoline composition consists essentially of isopentanol, ethanol, and essentially oxygen free base gasoline. In certain particularly preferred embodiments, isopentanol, ethanol and the essentially oxygen free base gasoline are the components of the gasoline composition, and no further components are present. In certain embodiments, isopentanol is provided in such an amount that the vol-% amount of isopentanol is equal to the vol-% amount of ethanol in the gasoline composition. Preferably, isopentanol is provided in such an amount that the vol-% amount of isopentanol is higher than the vol-% amount of ethanol in the gasoline composition. In certain preferred embodiments, isopentanol and optionally ethanol is/are provided in such an amount(s) that, in the gasoline composition, the vol-% ratio of ethanol to isopentanol is within a range from 1 :1 to 1 :3, more preferably within a range from 1 :2 to 1 :3, such as 5:11. Use of isopentanol and ethanol in a gasoline composition comprising essentially oxygen free base gasoline or use of isopentanol in a gasoline composition containing ethanol and essentially oxygen free base gasoline to adjust distillation behaviour, preferably to decrease the E70 value, and/or to increase motor octane number (MON) may yield a gasoline composition having an E70 value of at most 50 vol-%, preferably at most 46 vol-%, more preferably at most 40 vol-%, such as at most 35 vol-%, and/or a motor octane number (MON) of at least 85, or at least 86. In certain preferred embodiments, the gasoline composition has an E70 value within the range from 22 vol-% to 50 vol-%, preferably from 24 vol-% to 46 vol-%, more preferably from 24 vol-% to 40 vol-%, such as from 24 vol-% to 35 vol-% or from 24 vol-% to 30 vol-%, and/or a motor octane number (MON) of at least 85, or at least 86. The use of isopentanol may comprise blending isopentanol with a gasoline composition comprising ethanol and essentially oxygen free base gasoline.
A further advantage of using ethanol and isopentanol in combination is that the risk of phase separation decreases (compared to the risk of phase separations in blends of ethanol and base gasoline) as water solubility of isopentanol is smaller than water solubility of ethanol. A yet further advantage of using both ethanol and isopentanol in a gasoline composition is that the increase in vapour pressure typically caused by ethanol is mitigated by the presence of isopentanol. Isopentanol does not increase the vapour pressure of gasoline composition. The present disclosure further provides a gasoline composition comprising, based on the total volume of the gasoline composition, ethanol from 3 vol-% to 10 vol-%, preferably from 5 vol-% to 10 vol-%, more preferably from 5 vol-% to 7 vol-%, such as about 5 vol-%, isopentanol from 5 vol-% to 15 vol-%, preferably from 5 vol-% to 13 vol-%, more preferably from 7 vol-% to 13 vol-% or from 10 vol-% to 13 vol-%, and essentially oxygen free base gasoline 75 vol-% to 92 vol-%, preferably at least 77 vol-%, at least 78 vol-%, at least 80 vol-% or at least 82 vol-%, and/or preferably at most 90 vol-%, at most 88 vol-%, at most 87 vol-% or at most 85 vol-%. The sum of the vol-% amounts of ethanol, isopentanol, and essentially oxygen free base gasoline in such gasoline compositions is preferably at least 95 vol-%, more preferably at least 99 vol-%, even more preferably the gasoline composition consists essentially of ethanol, isopentanol, and essentially oxygen free base gasoline. Preferably, the vol-% amounts of ethanol and isopentanol are selected (from the herein mentioned ranges) so that the oxygen content of the gasoline composition is at most 3.7 wt-% based on the total weight of the gasoline composition. The gasoline composition may comprise equal vol-% amounts of ethanol and isopentanol, or the vol-% amount of isopentanol may be higher than the vol-% amount of ethanol, based on the total volume of the gasoline composition. Preferably the vol-% ratio of ethanol to isopentanol in the gasoline composition is within a range from 1 :1 to 1 :3, more preferably within a range from 1 :2 to 1 :3, such as 5:11. As described in the foregoing, such gasoline compositions are advantageous in that they have surprisingly high MON values and readily predictable distillation characteristics. These gasoline compositions may have a motor octane number (MON) of at least 85, preferably at least 86, and/or an E70 value of at most 50 vol-%, preferably at most 46 vol-%, more preferably at most 40 vol-%, such as at most 35 vol-%, or an E70 value within the range from 22 vol-% to 50 vol-%, preferably from 24 vol-% to 45 vol-%, more preferably from 24 vol-% to 40 vol-%, such as from 24 vol-% to 35 vol-% or from 24 vol-% to 30 vol-%.
In certain particularly preferred embodiments, the gasoline composition comprises, based on the total volume of the gasoline composition, ethanol from 5 vol-% to 7 vol-%, such as from 6 vol-% to 7 vol-%, and isopentanol from 7 vol-% to 15 vol-%, preferably from 11 vol-% to 13 vol-%, the gasoline composition essentially consisting of ethanol, isopentanol, and essentially oxygen free base gasoline, even more preferably isopentanol, ethanol and the essentially oxygen free base gasoline are the components of the gasoline composition, and no further components are present. Such gasoline compositions are advantageous in terms of MON and distillation characteristics.
The present disclosure also provides a method of preparing a gasoline composition, the method comprising providing ethanol, providing isopentanol, providing essentially oxygen free base gasoline, and blending ethanol, isopentanol, and essentially oxygen free base gasoline in such amounts that a gasoline composition comprising, based on the total volume of the gasoline composition, from to 3 vol-% to 10 vol-%, preferably from 5 vol-% to 10 vol-%, more preferably from 5 vol-% to 7 vol-%, such as about 5 vol-%, ethanol, from 5 vol-% to 15 vol-%, preferably from 5 vol-% to 13 vol-%, more preferably from 7 vol-% to 13 vol-% or from 10 vol-% to 13 vol-%, isopentanol, and from 75 vol-% to 92 vol-%, preferably at least 77 vol-%, at least 78 vol-%, at least 80 vol-%, or at least 82 vol-%, and/or preferably at most 90 vol-%, at most 88 vol-%, at most 87 vol-% or at most 85 vol-% essentially oxygen free base gasoline is formed. Preferably, ethanol, isopentanol, and the base gasoline are provided in such amounts that the sum of the vol-% amounts of ethanol, isopentanol, and the base gasoline in the formed gasoline composition is at least 95 vol-%, preferably at least 99 vol-%, more preferably such that the formed gasoline composition consists essentially of ethanol, isopentanol, and the base gasoline. In certain particularly preferred embodiments, isopentanol, ethanol and the essentially oxygen free base gasoline are the components of the gasoline composition, and no further components are present. Preferably, ethanol and isopentanol are provided in such amounts that the oxygen content of the formed gasoline composition is at most 3.7 wt-% based on the total weight of the gasoline composition. In certain embodiments, isopentanol and ethanol are provided in such amounts that the formed gasoline composition comprises equal vol-% amounts of ethanol and isopentanol, or the vol-% amount of isopentanol is higher than the vol-% amount of ethanol. Preferably, ethanol and isopentanol are provided in such amounts that the vol-% ratio of ethanol to isopentanol in the formed gasoline composition is within a range from 1 :1 to 1 :3, more preferably within a range from 1 :2 to 1 :3, such as 5:11 . The method of preparing the gasoline composition may include selecting components, optionally analysis thereof, addition of components by volume optionally in an order and blending to obtain the gasoline composition. The blending may be performed for example at a refinery or at a gasoline distribution station.
EXAMPLES
The following examples are provided to better illustrate the claimed invention and are not to be interpreted as limiting the scope of the invention. To the extent that specific materials are mentioned, it is merely for purposes of illustration and is not intended to limit the invention.
Five gasoline compositions were prepared by blending renewable ethanol and/or renewable isopentanol with base gasoline. Two different base gasolines were used; an oxygen free stock for oxygenate blending (BOB) and an oxygen free base gasoline blended from fossil cuts (BG). Compositions of the two base gasolines BOB and BG are shown in Table 1. The isopentanol used in the prepared gasoline compositions was 3-methyl-1 -butanol. Further, a gasoline composition was prepared by blending renewable ethanol and renewable n-pentanol with BG. Compositions of the prepared gasoline compositions are shown in Table 2. Prepared gasoline compositions AO, A1, A4, and A5 are reference examples. Literature values of properties of ethanol, isopentanol and n-pentanol are shown in Table 3. The values of Table 3 are compiled from: Masum et al., “Tailoring the key fuel properties using different alcohols (C2-C6) and their evaluation in gasoline engine”, Energ. Convers. Manage. 88, 2014, 382-390; Christensen et al., “Renewable oxygenated blending effect on gasoline properties”, Energ. Fuel., 25, 2011, 4723-4733, and Yanowitz et al “Utilization of renewable oxygenates as gasoline blend components”, NREL Technical report, 2011, Table 5. Properties of the prepared gasoline compositions are shown in Table 4. The values shown in Table 4 are analytical results (measured values) with the exception of the oxygen contents of the gasoline compositions which have been calculated based on the theoretical amount of oxygen in ethanol, isopentanol, and/or n-pentanol. The theoretical amounts of oxygen shown in Table 2 were used in said calculations. Table 1. Compositions of BOB and BG base gasolines.
GC-MS refers to gas chromatography-mass spectrometry, and PONA to paraffins, olefins, naphthenes and aromatics. PONA analysis by GC-MS of gasoline is well known in the field.
Table 2. Compositions of prepared gasoline compositions.
Table 3. Properties of isopentanol, ethanol, and n-pentanol. Table 4. Properties of the prepared gasoline compositions and of BOB.
As seen from the results of Table 4, the analysed properties of all of the prepared gasoline compositions A0-A5 complied with the requirements of EN 228:2012, Amended 2017 (Table 1 and Table 3). The volume percentages of the alcohol(s) in the prepared gasoline compositions were selected so that a similar oxygen content of 3.6-3.7 wt-%, based on the total weight of the respective gasoline composition, was obtained, with the exception of reference example A5. Inclusion of isopentanol in the gasoline composition did not increase vapor pressure, as seen for example by comparing the vapor pressures of AO (BOB+ethanol), A1 (BOB+isopentanol), and A2 (BOB+ethanol+isopentanol). As the compositions of the base gasolines BOB and BG were different from each other, the vapour pressure values of the blends containing BOB and of the blends containing BG cannot as such be compared.
RON and MON were analysed for each of A0-A5 and BOB. The analysed RON and MON values of A0-A5 and BOB as well as calculated RON and MON values of A0- A5 are shown in Table 5.
Predicted RON and MON were calculated for each of A0-A5 according to formulas 3 and 4, respectively. Blend RON (bRON) and blend MON (bMON) for ethanol used in said calculations were 128.0 and 96.0, respectively. For each of isopentanol and n-pentanol bRON and bMON were calculated based on linear calculations according to formulas 1 and 2, respectively. In the formulas, pentanol refers to isopentanol or n-pentanol and x refers to the vol-%/100 of the respective component. Calculation of bRON and bMON is known in the field and has been published for example in US4244704A. The calculated bRON and bMON of isopentanol are shown in Table 6. The calculated bRON and bMON of n-pentanol were 84.0 and 69.8, respectively (composition A4).
Table 5. Analysed and calculated MON and RON values. Table 6. Calculated bRON and bMON for isopentanol.
As seen in Table 5, surprisingly the analysed MONs of A2 (BOB+ethanol+isopentanol) and A3 (BG+ethanol+isopentanol) were clearly higher than the calculated (predicted) MONs of A2 and A3. A similar effect was not observed for reference examples AO (BOB+ethanol), A1 (BOB+isopentanol), A5 (BG+isopentanol), and A4 (BG+n-pentanol). Instead, the calculated MONs and the analysed MONs of AO, A1 , A5, and A4, respectively, corresponded well with each other.
The surprisingly good MONs of A2 and A3 (compared to their predicted MONs) is a synergistic effect of using both ethanol and isopentanol in the gasoline compositions A2 and A3. As shown by the reference examples, such surprising increase in MON compared to the predicted MON was not observed for gasoline compositions including only one of ethanol and isopentanol. Also, as seen by comparing the calculated and the analysed MON of A4, no increase in the MON compared to the predicted MON was obtained by including both ethanol and n-pentanol in the composition. Accordingly, the surprising increase in the MON observed for ethanol and isopentanol when used together is not achieved by inclusion or addition of just any oxygenate. No synergistic effect was observed for the RONs.
As seen in Table 5, the analysed MON of A3 (BG+ethanol+isopentanol) was higher than the analysed MON of A5 (BG+isopentanol). Similarly, the analysed MON of A2 (BOB+ethanol+isopentanol) was higher than the analysed MON of both AO (BOB + ethanol) and A1 (BOB + isopentanol). Accordingly, in addition to an increase in MON compared to predicted values, the synergistic effect of ethanol and isopentanol on MON was also seen in comparison to similar gasoline compositions containing only one of ethanol and isopentanol (lacking the other). In fact, both A3 and A2 had higher analysed MONs than any of AO, A1 , A4 and A5.
It is particularly unexpected that the MONs of A2 and A3 were higher than the MON of AO as the MON of neat ethanol and the bMON of ethanol are higher than the MON of neat isopentanol and the bMONs of isopentanol. Accordingly, inclusion of isopentanol while reducing the vol-% of ethanol in the gasoline composition was expected to reduce MON rather than increase it. Surprisingly, it was found that a higher MON was achieved by inclusion of isopentanol (while reducing the vol-% of ethanol), as seen from the comparison of the analysed MONs of A2, A3, and AO. Even more surprisingly, the analysed MON of A3, containing more isopentanol than ethanol, was higher than the analysed MON of A2, containing isopentanol and ethanol in equal amounts (and having a lower vol-% ethanol than A3). These findings further demonstrate the synergistic effect of ethanol and isopentanol on MON when used in combination in a gasoline composition. A further advantage of using both ethanol and isopentanol in a gasoline composition is that the distillation characteristics of such gasoline composition is more predictable compared to the distillation behaviour of gasoline compositions of oxygen free base gasoline and ethanol. The distillation behaviour of A2 and A3 were analysed, including E70, E100 and E150, and the distillation curve of A2 and A3, respectively, were constructed. Further, as reference examples, the distillation behaviour of BOB, AO, and a blend consisting of 75 vol-% oxygen free base gasoline and 25 vol-% ethanol (E25) were analysed, respectively, including E70, E100 and E150, and the distillation curves of each of BOB, AO and E25 were constructed. The distillation curves are shown in Fig. 1 (BOB, E25, AO, A2, and A3). In Fig. 1, temperature (y-axis) is plotted as a function of share (vol-%) evaporated of the total volume (x-axis) at standard atmospheric pressure.
Table 7. Distillation behaviour of gasoline compositions AO, E25, A2, A3, and BOB.
As discussed in the foregoing, gasoline compositions containing ethanol, for example in an amount from 3 vol-% to 25 vol-%, typically display, due to azeotropic behaviour of ethanol, a distillation curve with a decreased slope roughly starting from the 30 vol-% evaporated temperature, the slope rejoining the roughly linear (steady) slope once all the ethanol has distilled off. Typically, the decrease in the slope of the distillation curve coincides with the E70 point thus affecting in an unpredictable manner the E70 of the ethanol containing gasoline composition. As the E70 is typically regulated by gasoline standards, e.g. EN 228:2012, Amended 2017 (Table 3), this may cause the ethanol containing gasoline composition to be substandard.
As seen in Fig. 1, the aforementioned decrease in the slope of the distillation curve is very prominent for E25 and also A0 (BOB+ethanol) in comparison for example to the distillation curve of neat BOB. For the gasoline compositions containing both ethanol and isopentanol, the decrease in the slope of the distillation curve is either reduced or shortened (A2 compared to AO) or no decrease in the slope was observed around the E70 point (A3). Accordingly, a higher vol-% amount of isopentanol than of ethanol in the gasoline composition is beneficial in that it reduces or shortens the decrease in the slope of the distillation curve particularly well or even removes it. As seen in Table 7, inclusion of both isopentanol and ethanol in the gasoline composition leads to a decrease in the E70 value. The E70 value of AO did not fulfil the requirements of EN 228:2012, Amended 2017 (Table 3), whereas A2, and A3 both had a E70 value within the limits allowed by EN 228:2012, Amended 2017 (Table 3). Accordingly, isopentanol may be used to adjust the distillation characteristics (improve predictability of distillation characteristics) of gasoline compositions comprising ethanol and oxygen free base gasoline, bringing the distillation curve closer to having a steady slope, resembling more the distillation behaviour of gasoline compositions consisting of hydrocarbons. Adjusting the distillation behaviour of gasoline compositions comprising ethanol and oxygen free base gasoline with isopentanol decreases the E70 value of the gasoline composition, which is beneficial for producing on-standard gasoline.
Also, using renewable ethanol and renewable isopentanol in combination allows increasing the content of renewable compounds (bio-content) in a gasoline composition while complying with requirements of gasoline standards, e.g. EN 228:2012 Amended 2017 (Tables 1 and 3). In fact, using ethanol and isopentanol together/in combination (as renewable gasoline components) alleviates some of the problems encountered by using ethanol, such as improves distillation characteristics of the gasoline composition, and improves the MON of the gasoline composition.
Various embodiments have been presented. It should be appreciated that in this document, words comprise, include, and contain are each used as open-ended expressions with no intended exclusivity.
The foregoing description has provided by way of non-limiting examples of particular implementations and embodiments a full and informative description of the best mode presently contemplated by the inventors for carrying out the invention. It is however clear to a person skilled in the art that the invention is not restricted to details of the embodiments presented in the foregoing, but that it can be implemented in other embodiments using equivalent means or in different combinations of embodiments without deviating from the characteristics of the invention.
Furthermore, some of the features of the afore-disclosed example embodiments may be used to advantage without the corresponding use of other features. As such, the foregoing description shall be considered as merely illustrative of the principles of the present invention, and not in limitation thereof. Hence, the scope of the invention is only restricted by the appended patent claims.