U.S. patent application number 16/960846 was filed with the patent office on 2020-10-29 for a method for reducing particulate emissions.
The applicant listed for this patent is SHELL OIL COMPANY. Invention is credited to Allen Ambwere ARADI, Roger Francis CRACKNELL, Valerio PELLICCIARI.
Application Number | 20200339898 16/960846 |
Document ID | / |
Family ID | 1000004985349 |
Filed Date | 2020-10-29 |
United States Patent
Application |
20200339898 |
Kind Code |
A1 |
CRACKNELL; Roger Francis ;
et al. |
October 29, 2020 |
A METHOD FOR REDUCING PARTICULATE EMISSIONS
Abstract
A method for reducing particulate emissions from a direct
injection spark-ignition engine, wherein the method comprises
fuelling the engine with a gasoline composition, wherein the
gasoline composition comprises a hydrocarbon base fuel comprising
not greater than 5% v aromatics of at least 9 carbon atoms, based
on the base fuel, a T90 of up to 150.degree. C. and a final boiling
point not greater than 190.degree. C.
Inventors: |
CRACKNELL; Roger Francis;
(Manchester, GB) ; ARADI; Allen Ambwere; (Houston,
TX) ; PELLICCIARI; Valerio; (Manchester, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHELL OIL COMPANY |
HOUSTON |
TX |
US |
|
|
Family ID: |
1000004985349 |
Appl. No.: |
16/960846 |
Filed: |
January 8, 2019 |
PCT Filed: |
January 8, 2019 |
PCT NO: |
PCT/EP2019/050308 |
371 Date: |
July 8, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62615459 |
Jan 10, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10L 1/023 20130101;
C10L 1/06 20130101; C10L 2200/0423 20130101; C10L 10/02 20130101;
C10L 2270/023 20130101 |
International
Class: |
C10L 1/06 20060101
C10L001/06; C10L 1/02 20060101 C10L001/02; C10L 10/02 20060101
C10L010/02 |
Claims
1. A method for reducing particulate emissions from a direct
injection spark-ignition engine, wherein the method comprises
fuelling the engine with a gasoline composition, wherein the
gasoline composition comprises a hydrocarbon base fuel comprising
not greater than 5% v aromatics of at least 9 carbon atoms, based
on the base fuel, a T90 of up to 150.degree. C. and a final boiling
point not greater than 190.degree. C.
2. The method of claim 1 wherein the hydrocarbon base fuel has a
final boiling point of not greater than 180.degree. C.
3. The method of claim 1 or 2 wherein the reduction of particulate
emissions is measured by a decrease in PM index (SAE Technical
Paper 2010-01-2115) of the gasoline composition.
4. The method of any of claims 1 to 3 wherein the gasoline
composition has a PM index of 1.0 or less.
5. The method of any of claims 1 to 4 wherein the gasoline
composition contains 0 to 10% v of at least one oxygenate selected
from methanol, ethanol, isopropanol and isobutanol,
diethylcarbonate.
6. The method of any of claims 1 to 5 wherein the hydrocarbon base
fuel contains 10 to 20% v olefins.
7. The method of any of claims 1 to 6 wherein the hydrocarbon base
fuel contains 12 to 18% v olefins.
8. The method of any of claims 1 to 7 wherein the hydrocarbon base
fuel contains not greater than 5% v olefins of at least 10 carbon
atoms, based on the base fuel.
9. The method of any of claims 1 to 8 wherein the base fuel has
initial boiling point in the range 30 to 40.degree. C., T10 in the
range 45 to 57.degree. C., T50 in the range 82 to 104.degree. C.,
T90 in the range 140 to 150.degree. C.
10. The method of any of claims 1 to 9 wherein the fuel composition
comprises one or more antioxidants.
11. Use of a gasoline composition for reducing particulate
emissions from a direct injection spark-ignition engine, wherein
the gasoline composition comprises a hydrocarbon base fuel
comprising not greater than 5% v aromatics of at least 9 carbon
atoms, based on the base fuel, a T90 of up to 150.degree. C. and a
final boiling point not greater than 190.degree. C.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a method for reducing particulate
emissions from a direct injection spark-ignition engine.
BACKGROUND OF THE INVENTION
[0002] There is increasing concern about the environmental effects
of particulate emissions from spark-ignition combustion engines,
particularly from direct injection spark-ignition engines. This has
resulted in a growing demand for motor vehicles that operate with
reduced particulate emissions.
[0003] Current hydrocarbon fuels developed for spark-ignition
combustion engines may not be optimised or indeed beneficial for
direct injection spark-igntion engines, particularly when it comes
to levels of particulate emissions. It would therefore be desirable
to find ways of reducing the particulate emissions from the
operation of a direct-injection spark ignition engine.
[0004] WO2004/113476 discloses gasoline compositions meeting
certain parameters whose use as a fuel in a spark ignition engine
results in improved stability of engine crank case lubricant.
However, there is no mention in this document of the use of such a
fuel for providing reduced particulate emissions in a
direct-injection spark ignition engine.
SUMMARY OF THE INVENTION
[0005] According to the present invention there is provided a
method for reducing particulate emissions from a direct injection
spark-ignition engine, wherein the method comprises fuelling the
engine with a gasoline composition, wherein the gasoline
composition comprises a hydrocarbon base fuel comprising not
greater than 5% v aromatics of at least 9 carbon atoms, based on
the base fuel, a T90 of up to 150.degree. C. and a final boiling
point not greater than 190.degree. C.
[0006] According to the present invention there is further provided
a use of a gasoline composition for reducing particulate emissions
from a direct injection spark-ignition engine, wherein the gasoline
composition comprises a hydrocarbon base fuel comprising not
greater than 5% v aromatics of at least 9 carbon atoms, based on
the base fuel, a T90 of less than 150.degree. C. and a final
boiling point not greater than 190.degree. C.
[0007] It has surprisingly been found that by selecting a gasoline
composition meeting certain parameters the particulate emissions
from a direct injection spark-igntion engine are reduced.
DETAILED DESCRIPTION OF THE INVENTION
[0008] Low C9+ aromatics content together with a T90 of less than
150.degree. C. and a final boiling point of not greater than
190.degree. C. are believed to be key parameters in achieving
reduced particulate emissions from a direct-injection spark
ignition internal combustion engines fuelled by gasoline
compositions of the present invention.
[0009] By "not greater than 5% v aromatics of at least 9 carbon
atoms" is meant that the hydrocarbon base fuel contains amounts of
aromatics having 9 carbon atoms or more, respectively in the range
0 to 5% v, based on the base fuel.
[0010] The uses and methods of the present invention may be used to
achieve any degree of reduction in particulate emissions from a
direct-injection spark ignition engine, including reduction to zero
(i.e. eliminating particulate emissions). It may be used for the
purpose of achieving a desired target level of particulate
emissions. The method and use herein preferably achieves a 5%
reduction or more in particulate emissions from a direct injection
spark ignition engine, more preferably a 10% reduction or more in
particulate emissions from a direct injection spark ignition
engine, even more preferably a 15% reduction or more in particulate
emissions from a direct injection spark ignition engine, and
especially a 30% reduction or more in from a direct injection spark
ignition engine, compared with the use of a gasoline fuel
composition having a final boiling point of greater than
190.degree. C., a T90 of 150.degree. C. or more and comprising
greater than 5v % of aromatics having 9 carbon atoms or more.
[0011] Any suitable method for measuring particulate emissions from
direct injection spark ignition engines can be used herein. An
example of a suitable method for measuring particulate emissions
can be found in the following SAE paper: SAE 2010-01-2115 published
25th October 2010 which measures the reduction of particulate
emissions by a decrease in PM index of the gasoline composition.
Gasoline compositions suitable for use in the present invention
preferably have a PM index as measured according to the test method
disclosed in SAE 2010-01-2115 of 1.0 or less, more preferably 0.95
or less, even more preferably 0.9 or less.
[0012] Gasolines contain mixtures of hydrocarbons, the optimal
boiling ranges and distillation curves thereof varying according to
climate and season of the year. The hydrocarbons in a gasoline as
defined above may conveniently be derived in known manner from
straight-run gasoline, synthetically-produced aromatic hydrocarbon
mixtures, thermally or catalytically cracked hydrocarbons,
hydrocracked petroleum fractions or catalytically reformed
hydrocarbons and mixtures of these. Oxygenates (both fossil- or
bio-sourced) may be incorporated in gasolines, and these include
alcohols (such as methanol, ethanol, isopropanol, tert.butanol and
isobutanol) and ethers, preferably ethers containing 5 or more
carbon atoms per molecule, e.g. methyl tert.butyl ether (MTBE) or
ethyl tert.butyl ether (ETBE). The amount of oxygenates present in
the fuel composition is dependent upon the prevailing fuel
specification for oxygenate species. For example, the EN228
specification sets a maximum oxygen content of 3.73% oxygen by mass
and therefore the level of oxygenate content has to be adjusted to
comply with this.
[0013] It is preferred to avoid inclusion of tert.butanol or MTBE.
Accordingly, preferred gasoline compositions of the present
invention contain 0 to 10% by volume of at least one oxygenate
selected from methanol, ethanol, isopropanol and isobutanol.
[0014] Theoretical modelling has suggested that inclusion of
ethanol in gasoline compositions of the present invention will
further enhance stability of engine lubricant, particularly under
cooler engine operating conditions. Accordingly, it is preferred
that gasoline compositions of the present invention contain up to
10% by volume of ethanol, preferably 2 to 10% v, more preferably 4
to 10% v, e.g. 5 to 10% v ethanol.
[0015] Other oxygenates that may be included in the gasoline
compositions herein include diethyl carbonate (DEC) which is made
catalytically from ethanol and CO2, esters such as ethyl acetate
and ketone such as methyl ethyl ketone.
[0016] Oxygenates can help to reduce PN emissions through chemical
means.
[0017] Gasoline compositions according to the present invention are
advantageously lead-free (unleaded), and this may be required by
law. Where permitted, lead-free anti-knock compounds and/or
valve-seat recession protectant compounds (e.g. known potassium
salts, sodium salts or phosphorus compounds) may be present.
[0018] The octane level can be defined by RON, MON or the
anti-knock index (Aki) ((RON+MON)/2). If RON is specified, it will
generally be greater than 92. If anti-knock index is specified it
will generally be above 85.
[0019] Modern gasolines are inherently low-sulphur fuels, e.g.
containing less than 200 ppmw sulphur, preferably not greater than
50 ppmw sulphur.
[0020] Hydrocarbon base fuels as defined above may conveniently be
prepared in known manner by blending suitable hydrocarbon, e.g.
refinery, streams in order to meet the defined parameters, as will
readily be understood by those skilled in the art. Olefin content
may be boosted by inclusion of olefin-rich refinery streams and/or
by addition of synthetic components such as diisobutylene, in any
relative proportions.
[0021] Diisobutylene, also known as 2,4,4-trimethyl-1-pentene
(Sigma-Aldrich Fine Chemicals), is typically a mixture of isomers
(2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene) prepared
by heating the sulphuric acid extract of isobutylene from a butene
isomer separation process to about 90.degree. C. As described in
Kirk-Othmer, "Encyclopedia of Chemical Technology", 4.sup.th Ed.
Vol. 4, Page 725, yield is typically 90%, of a mixture of 80%
dimers and 20% trimers.
[0022] Gasoline compositions as defined above may variously include
one or more additives such as anti-oxidants, corrosion inhibitors,
ashless detergents, dehazers, dyes, lubricity improvers and
synthetic or mineral oil carrier fluids. Examples of suitable such
additives are described generally in U.S. Pat. No. 5,855,629 and
DE-A-19955651.
[0023] Additive components can be added separately to the gasoline
or can be blended with one or more diluents, forming an additive
concentrate, and together added to base fuel.
[0024] A preferred gasoline composition for use in the method of
the present invention comprises one or more antioxidants in order
to improve the oxidative stability of the gasoline composition. Any
antioxidant additive which is suitable for use in a gasoline
composition can be used herein. A preferred anti-oxidant for use
herein is a hindered phenol, for example BHT (butylated hydroxy
toluene). It is preferred that the gasoline composition comprises
from 10 ppmw to 100 ppmw of antioxidant.
[0025] Non-oxygenated high octane components that can be
bio-sourced and which suitable for use herein include iso-butylenes
or iso-octenes, iso-octane, triptane and iso-pentenes. These
non-oxygenated high octane compounds help to reduce PN emissions
through ignition and combustion optimization.
[0026] Preferred gasoline compositions used in the method of the
present invention have one or more of the following features:--
(i) the hydrocarbon base fuel contains at least 10% v olefins, (ii)
the hydrocarbon base fuel contains at least 12% v olefins, (iii)
the hydrocarbon base fuel contains at least 13% v olefins, (iv) the
hydrocarbon base fuel contains up to 20% v olefins, (v) the
hydrocarbon base fuel contains up to 18% v olefins, (vi) the base
fuel has initial boiling point (IBP) of at least 28.degree. C.,
(vii) the base fuel has IBP of at least 30.degree. C., (viii) the
base fuel has IBP up to 42.degree. C., (ix) the base fuel has IBP
up to 40.degree. C., (x) the base fuel has T.sub.10 of at least
42.degree. C., (xi) the base fuel has T.sub.10 of at least
45.degree. C., (xii) the base fuel has T.sub.10 of at least
46.degree. C., (xiii) the base fuel has T.sub.10 up to 58.degree.
C., (xiv) the base fuel has T.sub.10 up to 57.degree. C., (xv) the
base fuel has T.sub.10 up to 56.degree. C., (xvi) the base fuel has
T.sub.10 of at least 80.degree. C., (xvii) the base fuel has
T.sub.10 of at least 82.degree. C., (xviii) the base fuel has
T.sub.10 of at least 83.degree. C., (xix) the base fuel has
T.sub.10 up to 105.degree. C., (xx) the base fuel has T.sub.10 up
to 104.degree. C., (xxi) the base fuel has T.sub.10 up to
103.degree. C., (xxii) the base fuel has T.sub.90 at least
135.degree. C., (xxiii) the base fuel has T.sub.90 of at least
140.degree. C., (xxii) the base fuel has T.sub.90 of at least
142.degree. C., (xxv) the base fuel has T.sub.90 up to 150.degree.
C., (xxvi) the base fuel has T.sub.90 up to 145.degree. C., (xxvii)
the base fuel has 1.sub.90 up to 143.degree. C., (xxviii) the base
fuel has FBP not greater than 190.degree. C., (xxix) the base fuel
has FBP not greater than 185.degree. C., (xxx) the base fuel has
FBP not greater than 180.degree. C., (xxxi) the base fuel has FBP
not greater than 175.degree. C., (xxxii) the base fuel has FBP not
greater than 172.degree. C., (xxxiii) the base fuel has FBP of at
least 165.degree. C., and (xxxiv) the base fuel has FBP of at least
168.degree. C.
[0027] Examples of preferred combinations of the above features
include (i) and (iv); (ii) and (v); (iii) and (v); (vi), (viii),
(x), (xii), (xvi), (xix), (xxii), (xxv) and (xxix); (vii), (ix),
(xi), (xiv), (xvii), (xx), (xxiii), (x.times.v) and (x.times.x);
and (vii), (ix), (xii), (xv), (xviii), (xxi), (xxiv), (xxvii),
(xxxiii) and (xxxiv).
[0028] Use of the gasoline composition described herein can give
one of a number of benefits in addition to reducing particulate
emissions in a direct injection spark-ignition engine. These
benefits include reduced frequency of oil changes, reduced engine
wear, e.g. engine bearing wear, engine component wear (e.g.
camshaft and piston crank wear), improved acceleration performance,
higher maximum power output, and/or improved fuel economy.
[0029] The invention will be understood from the following
illustrative examples, in which, unless indicated otherwise,
temperatures are in degrees Celsius and parts, percentages and
ratios are by volume. Those skilled in the art will readily
appreciate that the various fuels were prepared in known manner
from known refinery streams and are thus readily reproducible from
a knowledge of the composition parameters given.
[0030] In the examples, particulate matter emissions tests on
gasoline compositions in direct injection spark ignition engines
fuelled by test fuels were effected using the following
procedure.
Examples
[0031] The fuel compositions of Examples 1-4 are shown in Table 2
below. Each of these are prepared from the gasoline base fuel
having the properties set out in Table 1 below, and for each
example the v % of heavy aromatics (aromatics having at least 10
carbon atoms) is adjusted such that it contains an amount of heavy
aromatics (C9+) as specified in Table 2 below. Thus, Example 1
contains 0% v heavy aromatics, Example 2 contains 4% v heavy
aromatics, Example 3 contains 8% v heavy aromatics and Example 4
contains 12% v heavy aromatics.
TABLE-US-00001 TABLE 1 (Properties of Base Fuel) IBP (.degree. C.)
31.9 T10 (.degree. C.) 47.3 T50 (.degree. C.) 102.0 T90 (.degree.
C.) 142.7 FBP (.degree. C.) 179.3 RVP (kPa) 65.1 RON 95.3 MON 82.9
Aki ((RON + MON)/2) 89.1 Sensitivity (RON - MON) 12.43 Paraffins (%
v) 49.7 Olefins (% v) 14.3 Aromatics (% v) 32.7 PM index 0.81 C9
aromatics (% v) 2.65 C10 aromatics (% v) 0.26 C11 aromatics (% v)
0.00 C12 aromatics (% v) 0
[0032] The fuel compositions in Table 2 are subjected to the
particulate matter emissions test described in SAE Paper
2010-01-2115 in order to measure their PN index. Results are shown
in Table 2 below.
TABLE-US-00002 TABLE 2 Example: 1 2 3 4 % v heavy (C9+) 0% v 4% v
8% v 12% v aromatics IBP (.degree. C.)) 32.9 32.65 32.95 33.27 T10
(.degree. C.) 49.0 48.2 49.32 50.50 T50 (.degree. C.) 100.1 102.5
106.11 109.90 T90 (.degree. C.) 134.7 144.1 148.52 153.88 FBP 152.9
189.6 201.90 211.72 RVP (kPa) 66.15 68.58 66.51 64.42 RON 96.7 96.0
96.51 97.12 MON 82.8 82.7 83.08 83.49 Aki 89.8 89.3 89.8 90.3
Sensitivity 13.9 13.3 13.4 13.6 Paraffins (% v) 44.9 44.5 42.66
40.81 Olefins (% v) 20.3 20.2 19.31 18.48 Aromatics (% v) 32.50
33.07 35.86 38.63 PM Index 0.75 0.89 1.08 1.315 C9 aromatics (% v)
0 3.00 5.98 8.44 C10 aromatics 0 0.70 1.25 2.30 (% v) C11 aromatics
0 0 (% v) C12 aromatics 0 0.30 0.77 1.24 (% v) C9+ aromatics 0 4.00
8.00 11.98 (% v)
DISCUSSION
[0033] As can be seen from the results in Table 2 above, the
gasoline compositions having a hydrocarbon base fuel comprising not
greater than 5% v aromatics of at least 9 carbon atoms, based on
the base fuel, a T90 of less than 150.degree. C. and a final
boiling point not greater than 190.degree. C., provide a greater
reduction in particulate emissions (as measured by a decrease in PM
index).
* * * * *