U.S. patent application number 12/867269 was filed with the patent office on 2010-12-09 for use of alcohols in fuels for spark ignition engines.
This patent application is currently assigned to MELANIE KUBERKA. Invention is credited to Melanie Kuberka, Peter Placzek.
Application Number | 20100307053 12/867269 |
Document ID | / |
Family ID | 40622139 |
Filed Date | 2010-12-09 |
United States Patent
Application |
20100307053 |
Kind Code |
A1 |
Kuberka; Melanie ; et
al. |
December 9, 2010 |
USE OF ALCOHOLS IN FUELS FOR SPARK IGNITION ENGINES
Abstract
The use of at least one C.sub.4 alcohol to increase the vapour
pressure of a fuel for spark-ignition engines comprising base fuel
and ethanol in which use the at least one C.sub.4 alcohol is added
to a fuel comprising base fuel and ethanol to produce a resultant
fuel mixture comprising 15-50% by volume of base fuel, 15-65% by
volume of ethanol and 15 to 50% C.sub.4 alcohol. The resultant fuel
mixture exhibits an adequately high vapour pressure, for example,
which meets the specification, and also exhibits a good start
behaviour even at winter temperatures
Inventors: |
Kuberka; Melanie; (Essen,
DE) ; Placzek; Peter; (Gladbeck, DE) |
Correspondence
Address: |
E I DU PONT DE NEMOURS AND COMPANY;LEGAL PATENT RECORDS CENTER
BARLEY MILL PLAZA 25/1122B, 4417 LANCASTER PIKE
WILMINGTON
DE
19805
US
|
Assignee: |
KUBERKA; MELANIE
ESSEN
DE
|
Family ID: |
40622139 |
Appl. No.: |
12/867269 |
Filed: |
February 5, 2009 |
PCT Filed: |
February 5, 2009 |
PCT NO: |
PCT/EP09/00787 |
371 Date: |
August 12, 2010 |
Current U.S.
Class: |
44/449 ; 44/447;
44/452 |
Current CPC
Class: |
C10L 1/023 20130101 |
Class at
Publication: |
44/449 ; 44/452;
44/447 |
International
Class: |
C10L 1/185 20060101
C10L001/185; C10L 1/182 20060101 C10L001/182 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 14, 2008 |
DE |
10 2008 008 818.8 |
Claims
1-19. (canceled)
20. A method for increasing the vapour pressure of a fuel
comprising base fuel and ethanol for spark ignition engines
comprising: adding at least one C.sub.4 alcohol to a fuel
comprising base fuel and ethanol to produce a resultant fuel
mixture; wherein the resultant fuel mixture comprises 15-50% by
volume of base fuel, 15-65% by volume of ethanol and 15 to 50%
C.sub.4 alcohol.
21. The method of claim 20 wherein the resultant fuel mixture
comprises: 20 to 46% by volume of a base fuel 20 to 60% by volume
of ethanol, and 20 to 50% by volume of C.sub.4 alcohol.
22. The method of claim 20 wherein the resultant fuel mixture
comprises: 19.5 to 44% by volume of a base fuel 21 to 59.5% by
volume of ethanol, and 21 to 49% by volume of C.sub.4 alcohol.
23. The method of claim 20 wherein the C.sub.4 alcohol is one or
more of n-butanol, secondary butanol, and isobutanol.
24. The method of claim 20 wherein the C.sub.4 alcohol is
isobutanol.
25. The method of claim 21 wherein the C.sub.4 alcohol is one or
more of n-butanol, secondary butanol, and isobutanol.
26. The method of claim 21 wherein the C.sub.4 alcohol is
isobutanol.
27. The method of claim 20 wherein the ethanol is predominantly of
natural origin.
28. The method of claim 20 wherein the C.sub.4 alcohol is
predominantly of natural origin.
29. The method of claim 20 wherein the base fuel comprises
predominantly a mixture of hydrocarbons with a Carbon-number
predominantly from 4 to 12.
30. The method of claim 29 wherein the mixture of hydrocarbons
comprises predominantly paraffins, naphthenes, and aromatics.
31. The method of claim 29 wherein the base fuel comprises 0-15% by
volume of ether.
32. The method of claim 31 wherein the ether is tertiary butyl
methyl ether, tertiary butyl ethyl ether, or a combination
thereof.
33. The method of claim 20 wherein the alcohol content of the
resultant fuel mixture is at least 50% by volume.
34. The method of claim 20 wherein the alcohol content of the
resultant fuel mixture is at least 70% by volume.
35. The method of claim 21 wherein the base fuel comprises
predominantly a mixture of hydrocarbons with a Carbon-number
predominantly from 4 to 12.
36. The method of claim 35 wherein the mixture of hydrocarbons
comprises predominantly paraffins, naphthenes, and aromatics.
37. The method of claim 35 wherein the base fuel comprises 0-15% by
volume of ether.
38. The method of claim 37 wherein the ether is tertiary butyl
methyl ether, tertiary butyl ethyl ether, or a combination
thereof.
39. The method of claim 21 wherein the alcohol content of the
resultant fuel mixture is at least 50% by volume.
40. The method of claim 21 wherein the alcohol content of the
resultant fuel mixture is at least 70% by volume.
41. The method of claim 23 wherein the base fuel comprises
predominantly a mixture of hydrocarbons with a Carbon-number
predominantly from 4 to 12.
42. The method of claim 41 wherein the mixture of hydrocarbons
comprises predominantly paraffins, naphthenes, and aromatics.
43. The method of claim 41 wherein the base fuel comprises 0-15% by
volume of ether.
44. The method of claim 43 wherein the ether is tertiary butyl
methyl ether, tertiary butyl ethyl ether, or a combination
thereof.
45. The method of claim 23 wherein the alcohol content of the
resultant fuel mixture is at least 50% by volume.
46. The method of claim 24 wherein the alcohol content of the
resultant fuel mixture is at least 50% by volume.
47. The method of claim 25 wherein the base fuel comprises
predominantly a mixture of hydrocarbons with a Carbon-number
predominantly from 4 to 12.
48. The method of claim 47 wherein the mixture of hydrocarbons
comprises predominantly paraffins, naphthenes, and aromatics.
49. The method of claim 47 wherein the base fuel comprises 0-15% by
volume of ether.
50. The method of claim 49 wherein the ether is tertiary butyl
methyl ether, tertiary butyl ethyl ether, or a combination
thereof.
51. The method of claim 25 wherein the alcohol content of the
resultant fuel mixture is at least 50% by volume.
52. The method of claim 26 wherein the alcohol content of the
resultant fuel mixture is at least 50% by volume.
53. A method of manufacturing a fuel comprising mixing of a mixture
I, comprising 15-30% by volume of a base fuel and 70-85% by volume
of ethanol with a mixture II, comprising 30-50% by volume of base
fuel and 50 to 70% by volume of C.sub.4 alcohol.
54. The method of claim 53 wherein mixture I and mixture II are
mixed in the ratio of 1:1 by volume.
55. The method of claim 53 wherein mixture I is an E70 or E85
gasoline and mixture II is a B50 or B70 gasoline.
Description
[0001] The invention relates to the use of alcohols in fuels for
spark-ignition engines and to the manufacture of fuels for spark
ignition engines. In addition to ethanol, these fuels also comprise
C.sub.4 alcohol.
[0002] Fuels for spark-ignition engines are engine fuels which are
suitable for engines with spark ignition. They usually contain a
mixture of different hydrocarbons with different boiling points,
which typically lie within a range from 26.degree. C. to
210.degree. C. at atmospheric pressure. However, this range is not
specifically predetermined, and may be dependent on the actual
composition of the hydrocarbons, the additives and other
components, as well as on the environmental conditions. Typically,
the hydrocarbon components of the fuels contain C.sub.4 to C.sub.10
hydrocarbons.
[0003] The requirements for spark-ignition fuels which must be
fulfilled in their production are multifaceted. They are the result
of laws and regulations, the distribution chain, and their use in
the engine. Added to these are production-specific conditions and
different drive concepts, which make a differentiation of the
spark-ignition fuel into different types necessary. In Germany,
minimum requirements are imposed by decrees in the form of DIN
Standards. These must be identifiable by appropriate identification
at the filling station. The Fuel Quality Decree introduced in 1993
and updated in 2004 and 2006, now only allows fuels which fulfil
all the requirements of the DIN Standard EN228. In the USA,
corresponding specifications are imposed by ASTM 4814.
[0004] In order to achieve optimum driving conditions, the fuel
should fulfil various different requirements of the vehicle. In
specific terms, this means: After a long cold night the engine
should start just as easily as it does in summer, that is, as if
the well-heated engine is restarted after a brief intermediate
stop. Also, the engine should not stall when idling, and should not
work in an erratic manner under high loads. Even under unfavourable
conditions there should be no interfering residues in the
aspiration system, combustion chamber, or in the oil sump.
[0005] The fuel should be adapted to these different, and in part
contradictory, requirements in such a way that a trouble-free,
reliable, and mutually-beneficial interplay is possible. Brand
manufacturers in Germany therefore mix what are referred to as
"mineral oil substitute components", such as alcohols and ethers,
to the base fuels in limited proportions, as well as chemical
active substances up to 0.5 percent by weight.
[0006] Particular requirements are specified for fuels with alcohol
contents from 0 to 85% by volume of ethanol, for use in what are
referred to as Flex-Fuel Vehicles. With what are referred to as E85
fuels, with 70 to 85% by volume of ethanol, the vapour pressures
for the cold start behaviour is particularly critical. Fuels with a
high alcohol content, such as ethanol or mixtures of different
alcohols are known. Mention may be made by way of example of the
Applications HK 106 428, US 2006/0137243, US 2004/0107634, and US
2004/123518.
[0007] It is also known to mix a refinery-typical "super benzine"
or gasoline having a Research Octane Number (also referred to as
RON) of 95 in summer or winter quality with 70 to 85% by volume of
bioethanol. A draft specification CWA 15293 in accordance with the
CEN Workshop Agreement of May 2005 and the Draft Standard E DIN
51625 (October 2007, Beuth Verlag) recommends a minimum of 35 kPa
vapour pressure for the summer months (Class A) and 50 kPa vapour
pressure for winter months (Class B). Depending on the vapour
pressure of the base super benzine or gasoline fuel, a vapour
pressure of the gasoline/ethanol mixture may not correspond to the
draft specification. In these cases, the ethanol concentration in
the mixture must be adjusted downwards. This is undesirable.
[0008] The object of the invention is therefore to provide a fuel
with high alcohol concentration which exhibits a sufficiently high
vapour pressure, for example, a pressure which meets the
specification. This is intended to enhance cold start behaviour,
for example to guarantee that the fuel exhibits good cold start
behaviour even under winter temperatures.
[0009] This object is resolved by the use of at least one C.sub.4
alcohol according to claim 1.
[0010] The base fuel is a conventional gasoline, for example, an
unleaded gasoline, for example such as is offered in Germany and
elsewhere in Europe with a RON of 95.
[0011] The minimum standards for unleaded gasoline, which has been
on offer at filling stations since 1984 as Normal, and additionally
since 1985 as Euro-Super and since 1989 as SuperPlus, were
specified in 1993 in the European Standard DIN EN 228. The
composition of spark-ignition fuels from German refineries in the
qualities Normal, Super, and Super-Plus, is to be found, for
example, in the DGMK Research Report 502-1 by the German Scientific
Association for Mineral Oil, Natural Gas, and Coals (also referred
to as DGMK). In this analysis the main constituents of the fuel
were determined, specifically as both the mean values as well as
the ranges. The basis for this analysis was the winter product from
the winter 2001/2002. Reference is made herein expressly to this
report. Specifically, the content was determined of 50 hydrocarbons
with 3 to 6 carbon atoms, 51 aromatics, and 3 oxygen containing
compounds. In addition, the total content of all representatives
with the same carbon content in each case was determined for all
paraffins, naphthenes, cyclic and acyclic olefins and aromatics.
Separately tested was the content of 10 diolefins and 15 polycyclic
aromatics. The spark-ignition fuels referred to were derived from
14 different refineries.
[0012] The resultant fuel according to the invention contains 15 to
50% by volume of such a base fuel.
[0013] The inclination of the gasoline to evaporation--its
volatility--is the central precondition for use as a spark-ignition
fuel, and at the same time is an essential quality feature. Because
gasoline is a mixture of many hydrocarbons it does not have a
defined boiling point, but a boiling range, which lies usually
between 30.degree. C. and 200.degree. C.
[0014] The fuel according to the invention comprises 15 to 65% by
volume of ethanol and 15 to 50% by volume of C.sub.4 alcohol. In
total, naturally, including any other components, if present, the
sum total of 100% by volume is always derived.
[0015] In principle, due to a high content of alcohols the
properties of the fuel are altered in comparison with a normal
fuel. One such property is, for example, the volatility.
[0016] The volatility is characterised by the boiling curve in a
temperature band of, in most cases, 30 to 200.degree. C., maximum
from 26 to 210.degree. C., and by the vapour pressure. The boiling
curve describes the proportion of evaporated fluid at different
temperatures; the vapour pressure is the result of the fuel
components which at a defined temperature in a closed container
convert from the fluid phase into the vapour phase.
[0017] The function of "evaporated gasoline fractions/temperature"
provides what is referred to as the boiling curve, the location and
characteristics of which allow persons skilled in the art to reach
conclusions regarding the behaviour of the fuel in the engine. In
principle, the volatility of the spark-ignition fuel must be
established in such a way that in all situations an ignitable
fuel-air mixture is available in the combustion chamber. Under
specific operating conditions, such as, for example, with a
particularly cold or particularly hot engine, this precondition is
hard to fulfil, such that quality differences in the fuels become
identifiable in the light of this criterion.
[0018] The ignitability of the mixture is influenced not only by
the fuel, but also by the engine concept. That is to say, there is
a difference as to whether the engine is being driven with "rich"
or "lean" mixtures.
[0019] For winter operation, the volatility of the spark-ignition
fuel is in general adapted to the cold ambient temperatures. For a
reliable cold start, the fuel should be as volatile as possible. A
low boiling curve in the lower range and a high vapour pressure
facilitate starting and warm-up of the engine , since a too low
volatility would lead to the mixture becoming lean due to
insufficient evaporation and excessive fuel condensation on the
walls of the intake manifold.
[0020] The requirements on the gasoline with a hot engine are
precisely the reverse. Under unfavourable conditions, components of
the fuel system can become so hot that a too large part of the fuel
evaporates ("vapour phase formation" in the fuel pump), boils out
of the float chamber of the carburettor, or forms vapour cushions
in the injection system. As a result, the fuel delivery is
interrupted and the mixture is over-enriched, which has a negative
effect on driving behaviour. These disturbances arise more often,
the hotter the fuel system becomes (pump, carburettor, and fuel
injection), and the lower the fuel delivery volume and system
pressure are. On the fuel side, an excessively high volatility
makes itself evident to disadvantageous effect. High ambient
temperatures in the summer increase the likelihood of faults. For
this reason, the fuel manufacturers blend their summer qualities in
such a way that the boiling curve in the lower range is high and
the vapour pressure is low compared to winter quality fuel. This
adjustment must not go so far, however, that difficulties arise
with the cold start.
[0021] Depending on the base fuel, in particular with mixtures of
fuels with a high ethanol content, the minimum vapour pressure to
be maintained according to the draft specification often cannot be
maintained, in particular for the winter product. The consequence
would be that the ethanol content would have to be lowered in order
to achieve the minimum vapour pressure.
[0022] Surprisingly, it has been found that, by mixing fuel
comprising base gasoline and ethanol (for example E85) with at
least one C.sub.4 alcohol, for example, such as may be present in
other fuels having a high concentration of C.sub.4 alcohols, an
increase in the mixture vapour pressure can be achieved which lies
above that of the individual fuels. In the laboratory, vapour
pressures (according to EN 13016-1) of various different ethanol
and butanol mixtures in the super gasoline were tested out.
[0023] The results are represented in Tables 1 and 2. The number
following the letters characterising the individual combination in
each case indicate the content of this combination in % by
volume.
[0024] The requirements referred to heretofore are fulfilled with
the fuel according to the invention, and in particular the cold
start properties are improved.
[0025] In principle, it can be determined that with mixtures of a
base fuel with a relatively high proportion of ethanol, an atypical
increase in the vapour pressure occurs if at least one C.sub.4
alcohol is added to this mixture, such that its content amounts to
at least 15% by volume in the resultant fuel mixture. Such an
increase in the vapour pressure would not be foreseeable for the
person skilled in the art. The effect is noted among fuels which
comprise after mixing, 15 to 50% by volume base fuel, 15 to 65% by
volume ethanol, and 15 to 50% by volume C.sub.4 alcohol. The effect
is especially marked among fuels which comprise after mixing, 20 to
46% by volume base fuel, 20 to 60% by volume ethanol, and 20 to 50%
by volume C.sub.4 alcohol and most particularly amongst fuels which
comprise after mixing, 19.5 to 44% by volume base fuel, 21 to 59.5%
by volume ethanol, and 21 to 49% by volume C.sub.4 alcohol. This
effect is particularly perceptible when the C.sub.4 alcohol is
n-butanol (also referred to as 1-butanol), secondary butanol (also
referred to as 2-butanol) or isobutanol (also referred to as
2-methyl-1-propanol), or a mixture of at least two of these
butanols.
[0026] From an analysis of the boiling behaviour (distillation
according to EN ISO 3405), a positive effect was determined on
mixing a fuel containing ethanol with a fuel containing butanol.
The distillation curves, running in plateau fashion in the range of
about 20 to 90% of evaporated volume, show in the mixtures
according to the invention, a constant rise and therefore a path
which is similar to that of a spark-ignition fuel.
[0027] The effects referred to are particularly favourable with
regard to the vapour pressure and also the boiling behaviour if the
C.sub.4 alcohol is an isobutanol.
[0028] With the ethanol contained in the fuel according to the
invention, it is in principle not of consequence for the properties
of the fuel from what sources the ethanol derives. For preference,
however, an ethanol is to be used which is at least predominantly
of natural origin, such as from biomass, because on combustion,
this ethanol develops carbon dioxide which is environmentally
neutral. For the same reason it is preferable for the C.sub.4
alcohol used to be likewise of predominantly natural origin.
[0029] The overall content of alcohols of the fuel according to the
invention is at least 50% by volume, but for preference at least
70% by volume.
[0030] As already mentioned, the base fuel is a fuel such as
unleaded gasoline for example which is commercially available at
the present time. This consists of a mixture of hydrocarbons with a
Carbon-number of predominantly from 4 to 12. Its main components
are predominantly paraffins, naphthenes, olefins, and aromatics. In
addition to this, the base fuel may comprise components containing
oxygen. In this situation, ethers are preferred. The ether content
can for preference amount to up to 15% by volume related to the
base fuel. As ethers well-suited is tertiary butyl methyl ether
(also referred to as MTBE), as well as tertiary butyl ethyl ether
(also referred to as ETBE) or mixtures thereof.
[0031] The invention further relates to a method for the
manufacture of the resultant fuel according to the invention, as
well as its use as a fuel for spark-ignition engines, in particular
for spark-ignition engines in motor vehicles.
[0032] For preference, the resultant fuel according to the
invention is manufactured from already existing fuel mixtures. One
of these mixtures is an E85 fuel already described, with a
proportion of 70 to 85% by volume of ethanol and 15 to 30% by
volume of base fuel (mixture (I)). The other mixture comprises 30
to 50% by volume of base fuel and 50 to 70% by volume of C.sub.4
alcohol (mixture (II)). The preferred mixing ratio of mixture I:II
is 1:1. Mixture I may be an E70 or E85 gasoline and mixture II may
be a B50 or a B70 gasoline. Preferred are mixtures of a mixture (I)
having 70% by volume of ethanol with a mixture (II) having 50% by
volume of C.sub.4 alcohol, in particular isobutanol. Preferably,
the ratio of mixture (I) to mixture (II) is in the range from 40:60
to 60:40, but in particular 50:50 or 1:1 respectively. Mixture (I),
however, may comprise up to 85% by volume of ethanol and mixture
(II) up to 70% by volume of C.sub.4 alcohol.
[0033] Basically, however, a C.sub.4 alcohol can not only be added,
as described, as a mixture with a base fuel to a mixture of a base
fuel with a high content of ethanol, but it is also possible for
C.sub.4 alcohol to be added in a high concentration (up to 100%) to
the latter mixture. In the final analysis, the concentration ratios
in the resultant mixtures are determinant. The invention therefore
further relates to the use of at least one C.sub.4 alcohol to
increase the vapour pressure of a fuel for spark-ignition engines
comprising base fuel and ethanol in which use the at least one
C.sub.4 alcohol is added to a fuel comprising base fuel and ethanol
to produce a resultant fuel mixture comprising 15-50% by volume of
base fuel, 15-65% by volume of ethanol and 15 to 50% C.sub.4
alcohols. The % by volume data relate in each case to the resultant
fuel mixture.
[0034] The resultant fuel mixture preferably has a water
concentration of less than 800 ppm by weight, for example in the
range 100 to 400 ppm by weight.
[0035] The invention will now be illustrated by way of example
only, by reference to the data in Tables 1 and 2. Vapour pressures
measured in the laboratory according to EN 13016-1, of various
different ethanol and butanol mixtures in super gasoline were
measured and are shown in Tables 1 and 2.
[0036] Differences between expected vapour pressures, as calculated
according to the relative volume amounts of the components, and
actual vapour pressures are also shown. The expected vapour
pressure was calculated according to the relative proportions by
volume of the components. For example, the expected vapour pressure
of a 70 vol % iB50/30 vol % E70 mixture was calculated as 70% of
the vapour pressure of iB50 plus 30% of the vapour pressure of E70.
The data in the Tables show that the use of at least one C.sub.4
alcohol increases the vapour pressure of the fuel comprising base
fuel and ethanol beyond that which would be expected according to
the summing in proportion to their amounts, of the vapour pressures
of the various gasoline/ethanol and gasoline/butanol mixtures.
Thus, for example, 1B50 was found to have a vapour pressure of 56.1
kPa, 2B50 a vapour pressure of 55.7 kPa, iB50 a vapour pressure of
55.6 kPa, iB70 a vapour pressure of 40.7 kPa, E70 a vapour pressure
of 56.1 kPa and E85 a vapour pressure of 40.0 kPa. The vapour
pressures of various 50:50 (vol/vol) mixtures of these butanol and
ethanol mixtures were measured and found to be greater than the
average of the vapour pressures of the component mixtures. Thus,
the C.sub.4 alcohol had increased the vapour pressure of the fuel
mixture.
[0037] Also shown in Tables 1 and 2 is the difference in vapour
pressure between expected and measured for the various ratios of
E70/iB50 mixtures and E85/iB70 mixtures, the expected value being
calculated according to the relative proportions by volume of the
two mixtures.
[0038] The increase in vapour pressure caused by the C.sub.4
alcohol is shown in the Tables.
TABLE-US-00001 TABLE 1 Absolute measurement results E70 + iB50 E70
+ iB50 E70 + 1B50 E70 + 2B50 (2.sup.nd) E85 + iB70 (1st) B50/B70
E70/E85 Vapour Vapour Vapour Vapour Vapour concentration
concentration pressure pressure pressure pressure pressure [%] [%]
[kPa] [kPa] [kPa] [kPa] [kPa] 100 0 56.1 55.7 55.6 40.7 58.9 70 30
58.1 42.1 60 40 58.5 42.3 50 50 58.8 58.2 58.5 42.2 61.1 40 60 58.4
42.1 30 70 58.0 41.7 0 100 56.1 56.1 55.8 40.0 57.9 Differences in
relation to calculated vapour pressure according to relative volume
proportions E70 + iB50 E70 + iB50 E70 + 1B50 E70 + 2B50 (2.sup.nd)
E85 + iB70 (1st) B50/B70 E70/E85 Vapour Vapour Vapour Vapour Vapour
concentration concentration pressure pressure pressure pressure
pressure [%] [%] [kPa] [kPa] [kPa] [kPa] [kPa] 70 30 2.46 1.65 60
40 2.84 1.91 50 50 2.70 2.30 2.83 1.88 2.70 40 60 2.71 1.84 30 70
2.30 1.51 E = Ethanol 1B = 1-butanol 2B = 2-butanol iB = Isobutanol
50-85 = Alcohol content [% by volume] gasoline = RON95 unleaded
gasoline, "Super"
TABLE-US-00002 TABLE 2 Vapour pressure Ethanol C4 alcohol Gasoline
Total difference between Vapour pressure [% by [% by [% by [% by
expected and absolute volume] volume] volume] volume] measured
[kPa] measurement [kPa] 1B50 0 50 50 100 -- 56.1 E70 + 1B50 (1:1)
35 25 40 100 2.70 58.8 E70 70 0 30 100 -- 56.1 2B50 0 50 50 100 --
55.7 E70 + 2B50 (1:1) 35 25 40 100 2.30 58.2 E70 70 0 30 100 --
56.1 iB50 (2nd) 0 50 50 100 -- 55.6 E70 + iB50 (2nd) 21 35 44 100
2.46 58.1 E70 + iB50 (2nd) 28 30 42 100 2.84 58.5 E70 + iB50 (2nd)
35 25 40 100 2.83 58.5 E70 + iB50 (2nd) 42 20 38 100 2.71 58.4 E70
+ iB50 (2nd) 49 15 36 100 2.30 58.0 E70 (2nd) 70 0 30 100 -- 55.8
iB70 0 70 30 100 -- 40.7 E85 + iB70 25.5 49 25.5 100 1.65 42.1 E85
+ iB70 34 42 24 100 1.91 42.3 E85 + iB70 42.5 35 22.5 100 1.88 42.2
E85 + iB70 51 28 21 100 1.84 42.1 E85 + iB70 59.5 21 19.5 100 1.51
41.7 E85 85 0 15 100 -- 40.0 iB50 (1st) 0 50 50 100 -- 58.9 E70 +
iB50 (1st) 35 25 40 100 2.70 61.1 E70 (1st) 70 0 30 100 -- 57.9 E =
Ethanol 1B = 1-butanol 2B = 2-butanol iB = Isobutanol 50-85 =
Alcohol content [% by volume] gasoline = RON95 unleaded gasoline,
"Super" 1.sup.st = First measurement series 2.sup.nd = Second
measurement series
* * * * *