Note: Descriptions are shown in the official language in which they were submitted.
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LOW SULFUR DISTILLATE FUELS
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a Continuation-in-Part of U.S.S.N. 09/457,434 filed
December 7, 1999, which claims priority from U.S. Provisional Patent
Application
No. 60/111,346, filed December 8, 1998.
FIELD OF THE INVENTION
[0002] The present invention relates to a distillate fuel composition boiling
in
the range of about 190°C to 400°C with a T10 point greater than
205°C, and having
a sulfur level of less than about 100 wppm, a total aromatics content of about
15 to
35 wt.%, a polynuclear aromatics content of less than about 3 wt.%, wherein
the
ratio of total aromatics to polynuclear aromatics is greater than about 11.
BACKGROUND OF THE INVENTION
[0003] Diesel fuels are used widely in automotive transport largely due to
their
high fuel economy. However, one of the problems when such fuels are burned in
internal combustion engines is the pollutants in the exhaust gases that are
emitted
into the environment. For instance, some of the most common pollutants in
diesel
exhausts are oxides of nitrogen (hereafter abbreviated as "NOx"), particulate
matter
(including inter alia soot, adsorbed hydrocarbons and sulfates), unburned
hydrocarbons, and to a lesser extent carbon monoxide. Also, sulfur dioxide
emissions from diesel fuel exhaust gases are becoming increasingly a problem
due
to their affinity with after-treatment devices designed to reduce NOx and
particulate
emissions, thereby adversely affecting the functioning efficiency. The oxides
of
sulfur have been reduced considerably by reducing the sulfur levels in the
diesel
itself through ref ping operations such as by hydrodesulfurization. However,
further advances are required to meet increasingly demanding worldwide
legislation
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for progressively lower diesel powered vehicle exhaust emissions, especially
NOx
and particulate matter. An established trade-off exists between the two
pollutants,
i.e., NOx and particulate matter, whereby an increase in one leads to a
decrease ~in
the other, for a given engine and operating conditions.
[0004] A typical example of such a scenario is U.S. 5,792,339 in which a
diesel oil composition comprising 250-495 wppm sulfur, 5-8.6 wt.% of
polynuclear
aromatics (PNAs) and 10-23.9 wt.% total aromatics is disclosed. At the same
time,
further advances in sulfur-sensitive after-treatment technology have led to
increasing demand for lower levels of sulfur in diesel fuels.
[0005] There are a variety of analytical techniques that have been reported
for
measurement of total aromatics and polynuclear aromatics. In the discussion
and
claims that follow, aromatics and PNAs are measured by high performance liquid
chromatography (HPLC) as defined by test number IP 391/95, unless otherwise
indicated. IP391/95 is described in "IP Standard Methods for Analysis and
Testing
of Petroleum & Related Products, and British Standard 2000 Parts," 58th
edition,
February, 1999. This publication is incorporated herein by reference. Boiling
range distillation determinations were performed via gas chromatography
according
to ASTM D2887 providing the temperature at which 10% of the fuel was recovered
(T10) and the temperature at which 95% of the fuel was recovered (T95).
[0006] Hydrodesulfurization processes that reduce PNAs typically reduce
monocyclic aromatics as well as resulting in higher than desired hydrogen
consumption. Legislation requiring reduced sulfur content is also anticipated.
For
example, proposed sulfur limits for distillate fuels to be marketed in the
European
Union for the year 2005 is 50 wppm or less. Further, the maximum allowable
total
aromatics level for California Air Resources Board (GARB) reference diesel and
Swedish Class I diesel are 10 and 5 vol.%, respectively. Further, the CARB
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reference fuels allows no more than 1.4 vol.% polyaromatics (PNAs). In Europe,
from the year 2000, a limit of polynuclear aromatic content in diesel fuel has
been
set at 11 % by weight but no limit has been set for the total aromatic content
(including monocyclic aromatics) of the fuel. Consequently, much work is
presently being done in the hydrotreating art because of these proposed
regulations.
(0007] Hydrotreating, or in the case of sulfur removal, hydrodesulfurization,
is
well known in the art and typically requires treating the petroleum streams
with
hydrogen in the presence of a supported catalyst at hydrotreating conditions.
The
catalyst is usually comprised of a Group VI metal with one or more Group VIII
metals as promoters on a refractory support. Hydrotreating catalysts that are
particularly suitable for hydrodesulfurization, as well as
hydrodenitrogenation,
generally contain molybdenum or tungsten as the Group VI metal on alumina
support
promoted with cobalt, nickel, iron, or a combination thereof as the Group VIII
metal.
Cobalt promoted molybdenum on alumina catalysts are most widely used when the
limiting specifications are hydrodesulfurization, while nickel promoted
molybdenum
on alumina catalysts are the most widely used for hydrodenitrogenation,
partial
aromatic saturation, as well as hydrodesulfurization.
[0008] Much work is also being done to develop more active catalysts and to
improve reaction vessel designs in order to meet the demand for more effective
hydroprocessing processes. Various improved hardware configurations have been
suggested. One such configuration is a co-current design where feedstock flows
downwardly through successive catalyst beds and treat gas, which is typically
a
hydrogen-containing treat gas, also flows downwardly, co-current with the
feedstock. Another configuration is a countercurrent design wherein the
feedstock
flows downwardly through successive catalyst beds counter to upflowing treat
gas,
which is typically a hydrogen-containing treat-gas. The downstream catalyst
beds,
relative to the flow of feed, can contain high performance, but otherwise more
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sulfur sensitive catalysts because the upflowing treat gas carries away
heteroatom
components, such as HaS and NH3, that are deleterious to sulfur and nitrogen
sensitive catalysts.
[0009] Other process configurations include the use of multiple reaction
stages,
either in a single reaction vessel, or in separate reaction vessels. More
sulfur
sensitive catalysts can be used in the downstream stages as the level of
heteroatom
components becomes successively lower. European Patent Application 93200165.4
teaches such a two-stage hydrotreating process performed in a single reaction
vessel.
[0010] Distillate fuel compositions are taught that meet some of the low
emissions requirements. For example, U.S. Patent No. 5,389,111 teaches a
diesel
fuel composition having an aromatics content in the range from about 13 to 20
wt.%, a cetane number from about 54 to 60, which cetane number and aromatics
content being within a certain area defined in Figure 1 of that patent. U.S.
Patent
No. 5,389,112 teaches a low emissions diesel fuel composition having an
aromatics
content in the range of about 14.3 to 19.7 wt.%, a cetane number from about
53.4 to
60.8, which cetane number and aromatics content falls within a certain area of
Figure 1 of their patent.
[0011] While distillate fuel compositions exist that produce lower levels of
emissions than years past, there is still a need in the art for fuels with
ever lower
emissions levels that are needed to meet the ever stricter environmental
regulations.
[0012] It has now been found that by controlling the amount of sulfur, PNAs
and
total aromatics in the diesel fuel within specific limits, the amount of NOx
and
particulates emitted from exhausts can be synergistically reduced.
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SUMMARY OF THE INVENTION
[0013] In accordance with the present invention there is provided a distillate
fuel
composition boiling in the range of about 190°C to 400°C with a
T10 point greater
than 205°C, and having a sulfur level of less than about 100 wppm, a
total
aromatics content of about 15 to 35 wt.%, a polynuclear aromatics content of
less
than about 3 wt.%, wherein the ratio of total aromatics to polynuclear
aromatics is
greater than about 11.
[0014] In a preferred embodiment of the present invention the sulfur level is
less
than about 50 wppm.
[0015] In another preferred embodiment of the present invention the total
aromatics content is from about 20 to 35 wt.%.
[0016] In still another preferred embodiment of the present invention the
ratio of
total aromatics to polynuclear aromatics is at least 15.
[0017] In yet another embodiment, the invention is a fuel composition
comprising:
a distillate boiling in the range of about 190°C to 400°C with a
T10 point
greater than 205°C, and having a sulfur level of less than about 100
wppm, a total
aromatics content of about 15 to 35 wt.%, a polynuclear aromatics content of
less
than about 3 wt.%, wherein the ratio of total aromatics to polynuclear
aromatics is
greater than about 1 l, to which is added at least one of (i) one or more
lubricity aid,
(ii) one or more viscosity modifier, (iii) one or more antioxidant, (iv) one
or more
cetane improver, (v) one or more dispersant, (vi) one or more cold flow
improver,
(vii) one or more metals deactivator, (viii) one or more corrosion inhibitor,
(ix) one
or more detergent, and (x) one or more distillate or upgraded distillate.
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[0018] In still another preferred embodiment, the fuel is employed in a
compression ignition (e.g., diesel) engine, preferably in order to abate NOx
and
particulate emissions therefrom. More preferably, the fuel is employed in an
automotive diesel engine.
BRIEF DESCRIPTION OF THE FIGURES
[0019] Figure 1 hereof shows one preferred process scheme used to prepare
distillate fuel compositions of present invention. This process scheme
includes two
co-current hydrodesulfurization stages with once through hydrogen-containing
treat
gas in the second hydrodesulfurization stage.
[0020] Figure 2 hereof shows a plot that defines the composition of distillate
products of the present_invention where the sulfur content is less than 100
ppm and
the ratio of total aromatics to polynuclear aromatics is greater than about
11.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Feedstreams suitable for producing the low emissions distillate fuel
compositions of this invention are those petroleum based feedstreams boiling
in the
distillate range and above. Such feedstreams typically have a boiling range
from
about 190 to about 400°C, preferably from about 200 to about
370°C. These
feedstreams typically contain greater than about 3,000 wppm sulfur. Non-
limiting
examples of such feedstreams include virgin distillates, light cat cycle oils,
light
coker oils, etc. It is highly desirable for the refiner to upgrade these types
of
feedstreams by removing as much of the sulfur as possible, as well as to
saturate
aromatic compounds.
[0022] It is not critical how the distillate fuel compositions are produced.
One
preferred process for producing the fuel products of the present invention is
illustrated in Figure 1 hereof. The preferred process uses once-through
hydrogen
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treat gas in a second hydrodesulfurization stage and optionally in a first
hydrodesulfurization stage as well. Relatively low amounts of hydrogen are
utilized in the second hydrodesulfurization stage in such a way that very low
levels
of sulfur in the liquid product can be achieved while minimizing the amount of
hydrogen consumed via saturation of the aromatics. The first
hydrodesulfurization
stage will reduce the levels of both sulfur and nitrogen, with sulfur levels
being less
than about 1,000 wppm, preferably less than about 500 wppm. The second
hydrodesulfurization stage will reduce sulfur levels to less than about 100
wppm,
preferably to less than about 50 wppm. In the practice of this invention the
hydrogen in the treat gas reacts with impurities to convert them to HZS, NH3,
and
water vapor, which are removed as part of the vapor effluent, and it also
saturates
olefins and aromatics.
[0023] Miscellaneous reaction vessel internals, valves, pumps, thermocouples,
and heat transfer devices etc. are not shown for simplicity. Figure 1 shows
hydrodesulfurization reaction vessel Rlwhich contains reaction zones 12a and
12b,
each of which is comprised of a bed of hydrodesulfurization catalyst. It will
be
understood that this reaction stage can contain only one reaction zone or two
.or
more reaction zones. It is preferred that the catalyst be in the reactor as a
fixed bed,
although other types of catalyst arrangements can be used, such as slurry or
ebullating beds. Downstream of each reaction zone is a non-reaction zone, 14a
and
14b. The non-reaction zone is typically void of catalyst, that is, it will be
an empty
section in the vessel with respect to catalyst. Although not shown, there may
also
be provided a liquid distribution means upstream of each reaction stage or
catalyst
bed. The type of liquid distribution means is believed not to limit the
practice of
the present invention, but a tray arrangement is preferred, such as sieve
trays,
bubble cap trays, or trays with spray nozzles, chimneys, tubes, etc. A vapor-
liquid
mixing device (not shown) can also be employed in non-reaction zone 14a for
the
purpose of introducing a quench fluid (liquid or vapor) for temperature
control.
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_g_
[0024] The feedstream is fed to reaction vessel R1 via line 10 along with a
hydrogen-containing treat gas via line 18, which treat gas will typically be
from
another refinery process unit, such as a naphtha hydrof ner. It is within the
scope of
this invention that treat gas can also be recycled via lines 20, 22, and 16
from
separation zone S 1. The term "recycled" when used herein regarding hydrogen
treat gas is meant to indicate a stream of hydrogen-containing treat gas
separated as
a vapor effluent from one stage that passes through a gas compressor 23 to
increase
its pressure prior to being sent to the inlet of a reaction stage. It should
be noted that
the compressor will also generally include a scrubber to remove undesirable
species
such as HZS from the hydrogen recycle stream. The feedstock and hydrogen
containing treat gas pass, co-currently, through the one or more reaction
zones of
hydrodesulfurization stage R1 to remove a substantial amount of the
heteroatoms,
preferably sulfur, from the.feedstream. It is preferred that the first
hydrodesulfurization stage contain a catalyst comprised of Co-Mo, or Ni-Mo on
a
refractory support.
[0025] The term "hydrodesulfurization" as used herein refers to processes
wherein a hydrogen-containing treat gas is used in the presence of a suitable
catalyst which is primarily active for the removal of heteroatoms, preferably
sulfur,
and nitrogen, and for some hydrogenation of aromatics. Suitable
hydrodesulfurization catalysts for use in the reaction vessel R1 of the
present
invention include conventional hydrodesulfurization catalyst such as those
that are
comprised of at least one Group VIII metal, preferably Fe, Co or Ni, more
preferably Co and/or Ni, and most preferably Co; and at least one Group VI
metal,
preferably Mo or W, more preferably Mo, on a relatively high surface area
refractory support material, preferably alumina. Other suitable
hydrodesulfurization catalyst supports include refractory oxides such as
silica,
zeolites, amorphous silica-alumina, and titanic-alumina. Additives such as P
can
also be present. It is within the scope of the present invention that more
than one
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type of hydrodesulfurization catalyst be used in the same reaction vessel and
in the
same reaction zone. The Group VIII metal is typically present in an amount
ranging from about 2 to 20 wt.%, preferably from about 4 to 15%. The Group VI
metal will typically be present in an amount ranging from about 5 to 50 wt.%,
preferably from about 10 to 40 wt.%, and more preferably from about 20 to 30
wt.%. All metals weight percents are based on the weight of the catalyst.
Typical
hydrodesulfurization temperatures range from about 200°C to about
400°C with a
total pressures of about 50 psig to about 3,000 psig, preferably from about
100 psig
to about 2,500 psig, and more preferably from about 150 to 500 psig. More
preferred hydrogen partial pressures will be from about 50 to 2,000 psig, most
preferably from about 75 to 800 psig.
[0026] A combined liquid phase/vapor phase product stream exits
hydrodesulfurization stage R1 via line 24 and passes to separation zone Sl
wherein
a liquid phase product stream is separated from a vapor phase product stream.
The
liquid phase product stream will typically be one that has components boiling
in the
range from about 190°C to about 400°C, but will not have an
upper boiling range
greater than the feedstream. The vapor phase product stream is collected
overhead
via line 20. The liquid reaction product from separation zone S 1 is passed to
hydrodesulfurization stage R2 via line 26 and is passed downwardly through the
reaction zones 28a and 28b. Non-reaction zones are represented by 29a and 29b.
(0027] Hydrogen-containing treat gas is introduced into reaction stage R2 via
line 30 which may be cascaded or otherwise obtained from a refinery process
unit
such as a naphtha hydrofiner. Although this figure shows the treat gas flowing
co-
current with the liquid feedstream, it is also within the scope of this
invention that
.the treat gas can be introduced into the bottom section of reactor R2 and
flowed
countercurrent to the downward flowing liquid feedstream. It is preferred that
the
rate of introduction of hydrogen contained in the treat gas be less than or
equal to 3
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times the chemical hydrogen consumption of this stage, more preferably less
than
about 2 times, and most preferably less than about 1.5 times. The feedstream
and
hydrogen-containing treat gas pass, preferably cocurrently, through the one or
more
reaction zones of hydrodesulfurization stage R2 to remove a substantial amount
of
remaining sulfur, preferably to a level wherein the feedstream now has less
than
about 100 wppm sulfur, preferably less than about 50 wppm sulfur, and more
preferably less than 10 wppm sulfur. Suitable hydrodesulfurization catalysts
for use
in the reaction vessel R2 in the present invention include conventional
hydrodesulfurization catalyst, such as those previously described for use in
Rl.
Noble metal catalysts may also be employed, preferably the noble metal is
selected
from Pt and Pd or a combination thereof. Pt, Pd or the combination thereof is
typically present in an amount ranging from about 0.5 to 5 wt.%, preferably
from
about 0.6 to 1 wt.%. Typical hydrodesulfurization temperatures range from
about
200°C to about 400°C with a total pressures of about 50 psig to
about 3,000 psig,
preferably from about 100 psig to about 2,500 psig, and more preferably from
about
150 to 1,500 psig. More preferred hydrogen partial pressures will be from
about 50
to 2,000 psig, most preferably from about 75 to 1,000 psig. In one embodiment,
R2
outlet pressure ranges from about S00 to about 1000 psig.
[0028] It is within the scope of this invention that second reaction stage R2
can
be run in two or more temperature zones and in either cocurrent or
countercurrent
mode. By two or more temperature zones we mean that reaction stage R2 will
contain two or more separate beds of catalyst wherein at least one such bed is
operated at a temperature of at least 25°C lower than the other
catalyst beds
comprising the reaction stage. It is preferred that the lower temperature
zones) be
operated at a temperature of at least about 50°C lower than the higher
temperature
zone(s). It is also preferred that the lower temperature zone be the last
downstream
zones) with respect to the flow of feedstoclc. It is also within the scope of
this
invention that the second reaction stage be operated in either co-current or
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countercurrent mode. By countercurrent mode we mean that the treat gas will
flow
upwardly, counter to the downflowing feedstock.
[0029] The reaction product from second hydrodesulfurization stage R2 is
passed via line 35 to a second separation zone S2 wherein a vapor product,
containing hydrogen, is preferably recovered overhead via line 32 and may be
removed from the process via line 36. When either (i) all hydrogen-containing
treat
gas introduced into a reactor is consumed therein or (ii) unreacted hydrogen-
containing treat gas present in a reactor's vapor phase effluent and is
conducted
away from the reactor, then the treat gas is referred to as a "once-through"
treat gas.
Alternatively, all or a portion of the vapor product may be cascaded to
hydrodesulfurization stage R1 via Iines 34 and 16. The term "cascaded", when
used in conjunction with treat gas is meant to indicate a stream of hydrogen-
containing treat gas separated as a vapor effluent from one stage that is sent
to the
inlet of a reaction stage without passing through a gas compressor. That is,
the treat
gas flows from a downstream reaction stage to an upstream stage that is at the
same
or lower pressure, and thus there is no need for the gas to be compressed.
[0030] Figure 1 also shows several optional process schemes. For example, line
3~ can carry a quench fluid that may be either a liquid or a gas. Hydrogen is
a
preferred gas quench fluid and kerosene is a preferred liquid quench fluid.
[003I] The reaction stages used in the practice of the present invention are
operated at suitable temperatures and pressures for the desired reaction. For
example, typical hydroprocessing temperatures will range from about
200°C to
about 400°C at pressures from about 50 psig to about 3,000 psig,
preferably 50 to
2,500 psig, and more preferably about 150 to 1,500 psig. Furthermore, reaction
stage R2 can be operated in two or more temperature zones wherein the most
downstream temperature zone is at least about 25°C , preferably about
35°C, cooler
than the upstream temperature zone(s).
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[0032] For purposes of hydroprocessing and in the context of the present
invention, the terms "hydrogen" and "hydrogen-containing treat gas" are
synonymous and may be either pure hydrogen or a hydrogen-containing treat gas
which is a treat gas stream containing hydrogen in an amount at least
sufficient for
the intended reaction, plus other gas or gasses (e.g., nitrogen and light
hydrocarbons
such as methane) which.will not adversely interfere with or affect either the
reactions or the products. Impurities, such as HZS and NH3 are undesirable
and, if
present in significant amounts, will normally be removed from the treat gas,
before
it is fed into the R1 reactor. The treat gas stream introduced into a reaction
stage
will preferably contain at least about 50 vol.% hydrogen, more preferably at
least
about 75 vol.% hydrogen, and most preferably at least 95 vol.% hydrogen. In
operations in which unreacted hydrogen in the vapor effluent of any particular
stage
is used for hydroprocessing in any stage, there must be sufficient hydrogen
present
in the fresh treat gas introduced into that stage, for the vapor effluent of
that stage to
contain sufficient hydrogen for the subsequent stage or stages. It is
preferred in the
practice of the invention, that all or a portion of the hydrogen required for
the first
stage hydroprocessing be contained in the second stage vapor effluent fed up
into
the first stage. The first stage vapor effluent will be cooled to condense and
recover
the hydrotreated and relatively clean, heavier (e.g., Cq.+) hydrocarbons.
[0033] The liquid phase in the reaction vessels used in the present invention
will
typically be comprised of primarily the higher boiling point components of the
feed.
The vapor phase will typically be a mixture of hydrogen-containing treat gas,
heteroatom impurities like H2S and NH3, and vaporized lower-boiling components
in the fresh feed, as well as light products of hydroprocessing reactions. If
the
vapor phase effluent still requires further hydroprocessing, it can be passed
to a
vapor phase reaction stage containing additional hydroprocessing catalyst and
subjected to suitable hydroprocessing conditions for further reaction.
Alternatively,
the hydrocarbons in the vapor phase products can be condensed via cooling of
the
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vapors, with the resulting condensate liquid being recycled to either of the
reaction
stages, if necessary.
[0034] As discussed, the preferred process may be used to form the fuel
products
of the invention. Such distillate fuel products are characterized as having
relatively
low sulfur and polynuclear aromatics (PNAs) levels and a relatively high ratio
of
total aromatics to polynuclear aromatics. Such distillate fuels may be
employed in
compression-ignition engines such as diesel engines, particularly so-call
"lean-
burn" diesel engines. Such fuels are compatible with: compression-ignition
engine
systems such as automotive diesel systems utilizing (i) sulfur-sensitive NOx
conversion exhaust catalysts, (ii) engine exhaust particulate emission
reduction
technology, including particulate traps, and (iii) combinations of (i) and
(ii). Such
distillate fuels have moderate levels of total aromatics, reducing the cost of
producing cleaner-burning diesel fuel and also reducing COZ emissions by
minimizing the amount of hydrogen consumed in the process.
[0035] The preferred fuels may be combined with other distillate or upgraded
distillate. As discussed, the products are compatible with effective amounts
of fuel
additives such as lubricity aids, cetane improvers, and the like. While a maj
or
amount of the product is preferably combined with a minor amount of the
additive,
the fuel additive may be employed to an extent not impairing the performance
of
the fuel. While the specific amounts) of any additive employed will vary
depending on the use of the product, the amounts may generally range from 0.05
to
2.0 wt.% based on the weight of the product and additive(s), although not
limited to
this range. The additives can be used either singly or in combination as
desired.
[0036] In one embodiment, the distillate compositions of the present invention
,contain less than about 100 wppm, preferably less than about 50 wppm, more
preferably less than about 10 wppm sulfur. They will also have a total
aromatics
content from about 15 to 35 wt.%, preferably from about 20 to 35 wt.%, and
most
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preferably from about 25 to 35 wt.%. The PNA content of the distillate product
compositions obtained by the practice of the present invention will be less
than
about 3 wt.%, preferably less than about 2 wt.%, and more preferably less than
about 1 wt.%. The aromatics to PNA ratio will be at least about 11, preferably
at
least about 13, and more preferably at least about 15. Further, the distillate
fuels of
the present invention have relatively low amounts of low boiling material with
a
T10 distillation point of at least about 205°C. In one embodiment, the
aromatics to
PNA ratio will be at least about 11, preferably at least about 13, and more
preferably at least about 15. In another embodiment, the aromatics to PNA
ratio
ranges from 11 to about 50, preferably from 11 to about 30, and more
preferably
from 11 to about 20.
(0037] The term PNA is meant to refer to polynuclear aromatics that are
defined
as aromatic species having two or more aromatic rings, including alkyl and
olefin-
substituted derivatives thereof. Naphthalene and phenanthrene are examples of
PNAs. The term aromatics is meant to refer species containing one or more
aromatic ring, including alkyl and olefin-substituted derivatives thereof.
Thus,
naphthalene and phenanthrene are also considered aromatics along with benzene,
toluene and tetrahydronaphthalene. It is desirable to reduce PNA content of
the
liquid product stream since PNAs contribute significantly to emissions in
diesel
engines. However, it is also desirable to minimize hydrogen consumption for
economic reasons and to minimize COa emissions associated with the manufacture
of hydrogen via steam reforming. Thus, the current invention achieves both of
these by obtaining a high aromatics to PNA ratio in the liquid product.
[0038] The following examples are presented to illustrate the present
invention
and not to be taken as limiting the scope of the invention in any way.
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EXAMPLES 1-5
[0039] A virgin distillate feed containing from about 10,000 to 12,000 wppm
sulfur was processed in a commercial hydrodesulfurization unit (first
hydrodesulfurization stage) using a reactor containing both conventional
commercial NiMo/ A1a03 (Akzo-Nobel KF842/840) and CoMo/A1a03 (Akzo-Nobel
KF-752) catalyst under the following typical conditions: 300-350 psig; 150-180
psig outlet H2; 75% HZ treat gas; 500-700 SCF/B treat gas rate; 0.3-0.45 LHSV;
330-350°C. The liquid product stream from this first
hydrodesulfurization stage
was used as feedstream to the second hydrodesulfurization stage, which product
stream is described under the feed properties heading in Table 1 below. The
process conditions for this second hydrodesulfurization stage are also shown
in the
table below. A commercial NiMo catalyst (Criterion C-411 containing 2.6 wt.%
Ni
and 14.3 wt.% Mo) was used in all of the runs.
[0040] Examples 1 - 5 in Table 1 demonstrate that products with less than 100
wppm sulfur can be produced wherein the rate of introduction of hydrogen in
the
treat gas in the second reaction stage is less than or equal to three times
the
chemical hydrogen consumption. Examples 1-5 also demonstrate that products
with a total aromatics content between 15 and 35 wt.% can be produced with
total
aromatics/PNA ratios of greater than 11.
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Table 1
Example Example Example Example Example
1 2 3 4 5
Feed properties
to
second stage
S, wppm 340 340 99 266 375
N, wppm 75 75 52 45 101
API 35.7 35.6 35.5 37.6 361
T10,C 238 237 240 210 239
T95, C 367 367 374 363 366
Total aromatics, 26.51 25.99 27.06 25.26 24.07
wt%
(HPLC IP 391/95)
PNA, wt% 6.3 6.18 7.84 7.47 5.89
(HPLC IP 391/95)
H content, wt% 13.47 13.51 13.35 13.52 13.55
Product properties
from second stage
S, wppm 32.5 34.5 18.6 1.4 61
API 36.7 36.7 36 39.1 37.2
T10 C 235 235 238 207 236
T95 C 366 365 373 364 365
Total aromatics, 23.09 21.66 25.36 16.52 23.12
wt%
(HPLC IP 391/95)
PNA, wt% 2.02 1.39 1.94 1.21 1.74
(HPLC IP 391/95)
Total aromatics/PNA11.43 15.58 13.07 14.24 13.28
Hz consumption, 162 196 175 263 220
SCFB
Process conditions
for second stage
T, C 332 332 328 329 337
Pressure, psig 800 800 800 790 800
LHSV 1.1 1.1 1.3 0.58 1.1
Treat gas rate 490 480 520 555 530
(100% HZ) , SCFB
Treat gas rate/HZ3.0 2.4 3.0 2.3 2.4
consumption for
second stage
[0041] Comparative Examples A-F in Table 2 below are all fuel compositions
containing less than 100 ppm sulfur. Comparative examples A-F describe fuels
that
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WO 01/81510 PCT/USO1/12519
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have total aromatics levels greater than 15 wt.%. All of them have a ratio of
total
aromatics to PNAs less than about 10, which is outside the range of the fuel
compositions of the present invention.
CA 02404931 2002-09-25
WO 01/81510 PCT/USO1/12519
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O r, N 1
D1
O
~, M 'S-~'' 1~ 'O ~--i1
OMO N
~
Q, ~' ~ c
~
U W
-, N
..~
W Q1
~
p, ~ N 00
U W
-, N
O
~ \O N
M '~~'
p., ~ ~n N
~,
~ ~
U W
a1
M
c+-'due 'SON ~fi N
O ~
p ~ V ~ o
u ~
.
" ~, , ,~
b
~ r~
. .
E~
N N ~ ~ U
9 ~ ~ cd
,
. b N
"' 0 ~ ~
~
~ U ~ N ~ ~C
c
~
O ~ ~
~, .~ R~ ~
+"
U W W ~
N O
'~l'
y U
'
'~
,
_,
-
.
~
~ ~ [j o U M
a? ~ ~
, o N
4
~ ~
d
a
U W
~ A .b ~ o a
U ,-, v U d
~ . U
,-i
~~ ~~ w
~
~ H
v~ vi~ ~o ~ ~ o0
U '~' ,-' ~ N ~ 'r'
:G ,.~,
-~ ~ N ~ 0
b
.~ O ' O .~
~ ~ i
4 O
O
CA 02404931 2002-09-25
WO 01/81510 PCT/USO1/12519
-19-
[0042] The designations "FIA", "MS", and "SFC" are well known in the art as
analytical techniques. For example, "FIA" stands for fluorescence indicator
analysis, "MS" stands for mass spectrophotometry; and "SFC" stands for
supercritical fluid chromatography. Table 3 provides additional comparative
examples of distillate fuels that fall outside the range of this invention.
These data
were obtained from the following publications.
3-1 X. Li et al. "Comparison of the Exhaust Emissions of Diesel Fuels Derived
From Oil Sands and Conventional Crude Oil," SAE Technical Paper Series
982487, Oct. 19-22, 1998.
3-2 B. Martin et al., Influence of Future Fuel Formulations on Diesel Engine
Emissions - A Joint European Study," SAE Technical Paper Series 972966,
Oct. 13-16, 1997.
3-3 A. Gerini et al. "Automotive Direct Injection Diesel Engine Sensitivity to
Diesel Fuel Characteristics," SAE Technical Paper Series 972963, Oct. 13-
16, 1997.
3-4 T. W. Ryan III et al., "Diesel Fuel Composition Effects on Ignition and
Emissions," SAE Technical Paper Series 932735, Oct. 18-21, 1993.
3-5 M. A. Gonzalez et al., "A Low Emission Diesel Fuel: Hydrocracking
Production, Characterization and Engine Evaluations," SAE Technical Paper
Series 932731, Oct. 18-21, 1993.
CA 02404931 2002-09-25
WO 01/81510 PCT/USO1/12519
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3-6 C. I. McCarthy, "Diesel Fuel Property Effects on Exhaust Emissions from a
Heavy Duty Diesel Engine that Meets 1994 Emission Requirements," SAE
Technical Paper Series 922267, Oct. 19-22, 1992.
3-7 W. W. Lange, "The Effect of Fuel Properties on Particulates Emissions in
Heavy Duty Truck Engines Under Transient Operating Conditions," SAE
Technical Paper Series 9212425, Oct. 7-10, 1991.
3-8 C. Beatrice et al., "Potentiality of Oxygenated Synthetic Fuel and
Reformulated Fuel on Emissions from a Modern DI Diesel Engine," SAE
Technical Paper Series 1999-O1-3595, Oct. 25-28, 1999.
3-9 N. Mann et al., "Fuel Effects on The Low Temperature Performance of Two
Generations of Mercedes-Benz Heavy-Duty Diesel Engines," SAE Technical
Paper Series 1999-O1-3594, Oct. 25-28, 1999.
3-10 D. A. Kouremenos et al., "Experimental Investigation of the Effect of
Fuel
Composition on the Formation of Pollutants in Direct Injection Diesel
Engines," SAE Technical Paper Series 1999-O1-0189, Mar. 1-4, 1999.
3-11 C. Bertoli et al., "The Influence of Fuel Composition on Particuate
Emissions of DI Diesel Engines," SAE Technical Paper Series 932733, Oct.
18-21, 1993.
[0043] Data reported for the wt.% total aromatics content and PNAs are shown
along with the calculated ratio of wt.% aromatics / wt.% PNAs. The analytical
test
method for measurement of aromatics and PNAs is also indicated along with
sulfur
content and the T10 boiling point. Fuels # 1 - 127 all have an aromatics/PNA
ratio
less than 11. Fuels # 128 - 151 have a total aromatics content less than 15
wt.%.
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Fuels #152 and 153 have sulfur contents over 100 wppm. Fuels # 154-158 have
T10 boiling points less than 205°C. Thus, all of the fuels shown in
Table 3 fall
outside the range of the fuels of the present invention.
Table 3
Fuel Pu Fuel T10 Aromatics.PNAs. Arom./PNAAnal. TestS_.
. Ref. wpm
W.to
1 3-4 LSLC07 343.3 31.9 29.6 1.1 UV 1100
2 3-4 LCOS 286.7 42.7 39.4 1.1 UV 3200
3 3-4 LC04 268.3 60.5 55.5 1.1 UV 4100
4 3-4 LC03 250.6 57.2 50.4 1.1 W 4500
3-4 LC06 306.1 36.4 31.5 1.2 UV 5700
6 3-4 LCOO 246.7 43.7 37.4 1.2 UV 2600
7 3-4 LC07 339.4 37.8 31.4 1.2 UV 18500
8 3-4 LC02 230.6 55.2 40.8 1.4 UV 3500
9 3-7 DD9 218.0 34.33 24.9 1.4 HPLC IP391500
3-4 LSLC06 312.8 32.8 23.1 1.4 UV 400
11 3-11 TAC10 213.0 13.7 9.6 1.4 Mass Spec.1050
12 3-4 SRD3 252.2 13.3 8.9 1.5 UV 200
13 3-4 SRD2 240.6 I3.5 9 1.5 UV 100
14 3-4 SRD7 325.0 9.3 6.2 1.5 UV 1200
3-4 SRD4 267.8 12.5 8.2 1.5 UV 300
16 3-4 LSLC05 283.9 34.1 22.3 1.5 UV 100
17 3-4 SRDS 284.4 10.9 6.9 1.6 UV 400
18 3-4 SRD6 303.3 8.7 5.5 1.6 UV 700
19 3-4 LCG07 317.2 15.2 9.6 1.6 UV 13300
3-4 SRDO 241.1 11.4 7.1 1.6 UV 500
21 3-4 LCG06 296.1 14.7 8.5 1.7 UV 13200
22 3-4 LCG05 276.7 15.1 8.5 1.8 UV 14800
23 3-7 DD10 214.0 8.96 5.02 1.8 HPLC IP391400
24 3-4 LSLC04 261.7 36.8 20.2 1.8 UV 0
3-4 LSLCOO 222.2 35.8 I9.2 1.9 W 300
26 3-11 DAC20 210.0 20.6 10.8 1.9 Mass Spec.2320
27 3-1 F 189.0 23.5 12.2 I:9 SFC 299
28 3-4 LCG04 252.2 14.4 7.3 2.0 UV 13600
29 3-11 DAC10 210.0 14.8 7 2.1 Mass Spec.1200
3-4 LCGOl 223.9 15.7 7.3 2.2 UV 14100
31 3-11 TACS 212.0 7.5 3.4 2.2 Mass Spec.542
32 3-3 G1 22.1 9.7 2.3 Unreportedca.500
33 3-3 G6 3I.7 13.8 2.3 Unreportedca.500
34 3-4 LSLC03 244.4 35.8 15.4 2.3 UV 0
'
3-7 DD5 220.0 33.23 13.79 2.4 HPLC IP3911900
36 3-7 DD4 220.0 33.87 14 2.4 HPLC IP3911900
37 3-2 J4 206.0 24.7 10 2.5 Unreported39
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38 3-5 A 233.0 37.5 15.1 2.5 HPLC IP391 2815
39 3-1 A 183.0 10.8 4.3 2.5 SFC 466
40 3-7 DD11 225.0 30.14 11.86 2.5 HPLC IP391 2900
41 3-4 LCG03 230.0 13.8 5.2 2.7 UV 10800
42 3-4 LCO1 195.6 42.5 15.8 2.7 UV 1600
43 3-10 NS 26.5 9.8 2.7 Unreported ca.5000
44 3-4 LSLCG06 314.4 11.4 4.2 2.7 UV 500
45 3-11 LSC 200.0 16.9 6.2 2.7 Mass Spec. 1300
46 3-4 SRD 1 170.0 12.3 4.5 2.7 UV 100
47 3-4 LSLC02 228.9 35.4 12.5 2.8 UV 0
48 3-11 HSC 221.0 22.1 7.6 2.9 Mass Spec. 9420
49 3-1 Ref2 198.9 26.6 8.8 3.0 HPLC 351
50 3-9 Fuel G 214.0 33.9 11 3.1 HPLC IP391 1000
51 3-9 Fuel Gl 214.0 33.9 11 3.1 HPLC IP391 1000
52 3-9 Fuel H1 214.0 33.9 11 3.1 HPLC IP391 1000
53 3-9 Fuel H 199.0 24.4 7.9 3.1 HPLC IP391 1000
54 3-9 CS ADO 230.0 32.2 10.3 3.1 HPLC IP391 380
1
55 3-3 GS 36.6 11.7 3.1 Unreported ca.500
56 3-4 LSLCGOS 266.7 11.2 3.5 3.2 UV 400
57 3-9 Fuel E 215.0 34.6 10 3.5 HPLC IP391 800
58 3-4 LALC07 318.9 1.4 0.4 3.5 UV 0
59 3-2 JS 206.0 17 4.7 3.6 Unreported 35
60 3-1 C 185.0 24.5 6.7 3.7 SFC 460
61 3-9 Fuel F 199.0 30.7 8.3 3.7 HPLC IP391 800
62 3-9 Fuel F1 199.0 30.7 8.3 3.7 HPLC IP391 800
63 3-7 DD12 236.0 25.93 6.95 3.7 HPLC IP391 1700
64 3-4 LSLCG04 245.0 11 2.8 3.9 UV 200
65 3-11 HDS 217.0 24.2 6.1 4.0 Mass Spec. 445
66 3-9 Ref 207.0 25.8 5.7 4.5 HPLC IP391 440
67 3-4 LSLCGOO 219.4 10.5 2.3 4.6 UV 400
68 3-9 Fuel A 214.0 30.2 6.6 4.6 HPLC IP391 600
69 3-9 Fuel C 216.0 28.5 6.2 4.6 HPLC IP391 700
70 3-10 N6 25 5 5.0 Unreported ca.5000
71 3-4 LALC06 286.1 2.5 0.5 5.0 UV 0
72 3-4 LSLCO1 187.8 29.1 5.8 5.0 UV 100
73 3-10 N4 25.2 5 5.0 Unreported ca.5000
74 3-1 C10B 207.5 10.2 2 5.1 HPLC 131
75 3-4 LCG02 201.7 11.4 2.2 5.2 UV 11600
76 3-1 E 183.0 25.2 4.8 5.3 SFC 374
77 3-1 C30A 198.5 29.6 5.6 5.3 HPLC 270
78 3-9 Fuel B 197.0 26.2 4.9 5.3 HPLC IP391 500
79 3-10 N3 24.9 4.6 5.4 Unreported ca.5000
80 3-9 Fuel D 196.0 25.2 4.6 5.5 HPLC IP391 700
81 3-4 LALCG07 312.8 2.2 0.4 5.5 UV 0
82 3-4 LASRD7 323.9 1.1 0.2 5.5 UV 0
83 3-10 N7 26.5 4.8 5.5 Unreported ca.5000
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84 3-3 G7 8.4 1.5 5.6 Unreported ca.500
85 3-4 LSLCG03 222.2 10.2 1.8 5.7 UV 100
86 3-2 J11 224.0 16.5 2.9 5.7 Unreported 23
87 3-2 J12 231.0 13.2 2.3 5.7 Unreported 37
88 3-10 N2 25.5 4.4 5.8 Unreported ca.5000
89 3-2 J10 213.0 21.6 3.6 6.0 Unreported 75
90 3-1 S 1 OB 183.0 12 2 6.0 HPLC 2
91 3-6 D 233.0 38.4 8.6 6.1 MS 2425 510
92 3-6 E 233.0 38.4 8.6 6.1 MS 2425 510
93 3-6 F 233.0 38.4 8.6 6.1 MS 2425 510
94 3-7 DD8 196.0 38.68 6.35 6.1 HPLC IP391 300
95 3-11 TNCS 213.0 6.1 1 6.1 Mass Spec. 2
96 3-9 CS ADO 206.0 20.8 3.4 6.1 HPLC IP391 130
2
97 3-9 CS ADO 206.0 20.8 3.4 6.1 HPLC IP391 140
3
98 3-1 C20A 191.0 20 3.2 6.3 HPLC 31
99 3-3 G2 18 2.8 6.4 Unreported ca.500
100 3-11 HCK 179.0 6.7 1.04 6.4 Mass Spec. 50
101 3-2 J1 216.0 27 4.1 6.6 Unreported 100
102 3-4 LALCG06 286.7 2.7 0.4 6.8 UV 0
103 3-1 Refl 205.6 25.9 3.6 7.2 HPLC 287
104 3-4 LALC05 267.8 2.9 0.4 7.3 UV 0
105 3-4 LASRD6 297.2 1.5 0.2 7.5 UV 0
106 3-4 LALC04 247.2 3.9 0.5 7.8 UV 0
107 3-10 Nl 27.4 3.5 7.8 Unreported ca.5000
108 3-6 I 222.0 27.9 4.2 8.0 MS 2425 420
109 3-11 HDT40 214.0 16.9 2.1 8.0 Mass Spec. 2
110 3-4 LALCG05 264.4 3.3 0.4 8.3 UV 0
111 3-1 C20B 194.0 19.8 2.4 8.3 HPLC 134
112 3-5 H(cut) 234.1 8.5 1 8.5 HPLC IP391 10
113 3-4 LALCG04 245.6 3.4 0.4 8.5 UV 0
114 3-4 LASRDS 276.7 2.6 0.3 8.7 UV 0
115 3-4 LALCOO 215.0 3.5 0.4 8.8 UV 0
116 3-6 J 228.0 25.6 3.6 8.9 MS 2425 300
117 3-4 LASRD4 250.0 3.6 0.4 9.0 UV 0
118 3-2 J2 234.0 3.6 0.4 9.0 Unreported 1
119 3-1 C30B 198.5 30.2 3.3 9.2 HPLC 202
120 3-3 G4 15.7 1.7 9.2 Unreported ca.500
121 3-3 G3 8.5 0.9 9.4 Unreported ca.500
122 3-5 H 239.4 10.4 1.1 9.5 HPLC IP391 10
123 3-8 FSG 218.5 14.8 1.5 9.9 Unreported 18
124 3-4 LSLCG02 203.9 10.9 1.1 9.9 W 100
125 3-6 A 200.0 20 3.4 10.0 MS 2425 410
.
126 3-6 B 200.0 20 3.4 10.0 MS 2425 410
127 3-4 LALC03 230.0 4.1 0.4 10.3 UV 0
128 3-2 J7 192.0 1.8 0.05 36.0 Unreported 1
129 3-4 LALCGOO 224.4 3.3 0.3 11.0 W 0
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130 3-4 LASRDO 227.8 3.3 0.3 11.0 W 0
131 3-4 LALCG03 225.0 3.5 0.3 11.7 UV 0
132 3-4 LALC02 211.1 3.6 0.2 18.0 W 0
133 3-4 LALCG02 206.7 3.9 0.2 19.5 UV 0
134 3-11 DNC20 206.0 4.1 0.2 20.5 Mass Spec. 1
135 3-1 Ref3 244.8 4.2 0 N.A. HPLC 9
136 3-4 LALCGOl 190.0 4.5 0.2 22.5 UV 0
137 3-11 DNC10 208.0 4.6 0.4 11.5 Mass Spec. 1
138 3-4 LASRD3 226.7 5 0.4 12.5 UV 0
139 3-11 TNC 213.0 5 0.1 50.0 Mass Spec. 1
140 3-6 L 229.0 5.2 1.3 44.0 MS 2425 490
141 3-4 LALCO1 183.3 5.6 0.2 28.0 UV 0
142 3-4 LASRD2 196.7 5.8 0.3 19.3 UV 0
143 3-11 HDT70 211.0 6.6 0.5 13.2 Mass Spec. 1
144 3-4 LASRD 116.1 7.7 . 0.1 77.0 UV 0
1
145 3-5 Ref. K541216.7 9.8 0.8 12.3 HPLC IP391 390
146 3-4 LSLCGO1 182.2 10 0.6 16.7 UV 100
147 3-1 C10A 200.0 10.4 0.7 14.9 HPLC 8
148 3-6 C 198.0 11.7 1.6 16.9 MS 2425 110
149 3-1 S10A 175.5 11.7 0.5 23.4 HPLC 13
150 3-6 G 172.0 14.2 1.3 12.1 MS 2425 20
151 3-6 H 172.0 14.2 1.3 12.1 MS 2425 20
152 3-10 NO 25.7 1.1 23.4 Unreported ca.5000
153 3-6 K 236.0 17.1 4.4 13.8 MS 2425 110
154 3-1 S30An5 185.0 32.1 2.5 12.8 HPLC 85
155 3-1 S20Bnl 179.0 22.8 1.9 12.0 HPLC 31
156 3-1 S20A 181.0 20 1 20.0 HPLC 29
157 3-9 CS ADO 202.0 19.8 1.4 14.1 HPLC IP391 16
4
158 3-1 S30Bn1 186.5 31.3 2.5 12.5 HPLC 3
[0044] The area to the right of the vertical line in the Figure 2 hereof
defines the
preferred products of this invention. While Figure 2's abscissa is truncated
at 20, it
should be understood that the product total aromatics/PNA ratio of the
preferred
products may exceed 20. In addition to the total aromatics (15-35 wt.%) and
total
aromatics/PNA criteria, the preferred products have S levels less than about
100
wppm and a T10 point of >205°C.
(0045] By using the diesel fuel compositions of the present invention, the
level
of the pollutants NOx and particulate matter is reduced to values which comply
with current and projected levels specified in environmental legislation,
i.e., NOx
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below O.Sg/Km and particulate matter below O.OSg/Km. These values/levels are
significantly lower than that for comparable fuels in which the aromatic
content
split (i.e., the total aromatics to PNA ratio) falls outside the ranges of the
present
invention as shown in the examples below.
S [0046] The present invention is further illustrated with reference to the
examples
set forth in Table 4 below.
(0047] The following data was generated from two distillate fuels. The first
one,
Example 6, was prepared in a commercial hydrodesulfurization unit from a
virgin
distillate feed using a conventional CoMolA1z03 catalyst and represents a
typical
commercial diesel fuel composition. The second one, Example 5, is a
composition
according to the present invention, as set forth in Table 1. The properties of
these
two fuels are shown in Table 4 below.
Table 4
Example 6 Example 5
Sulfur (wppm) 400 61
Mono-aromatics (% wt) 19.26 21.38
Polynuclear aromatics 4.84 1.74
(% wt)
Total aromatics (% wt) 24.10 23.12
AromaticslPNAs 5.0 13.3
Density (kg/m3) 844.1 838.8
Cetane No. 55.8 56.5
T95 (C) 337.0 335.1
[0048] These fuels were run in a fleet of 3 light-duty diesel vehicles
encompassing traditional and modern technology, i.e., one with distributor
pump
technology, one with common rail fuel injection technology and one with
electronic
unit injector technology. Each fuel was tested three times in each vehicle (a
total of
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nine tests per fuel) comprising a cold-start legislated European type
certification
drive cycle (ECE + EUDC) in order to determine average particulate emissions
and
average NOx emissions for both fuels. These average values were then compared
to the predicted values for both fuels in accordance with the European
Programme
on Emissions, Fuel and Engine (EPEFE) technologies and the AutoOil equation
for
the effect of sulfur to determine the expected performance of the fuels now
used.
The EPEFE program is based on an established set of equations from testing of
11
diesel fuels in 19 vehicles to predict the emissions performance of a fleet of
vehicles based upon the fuel parameters: cetane no., density and polycyclic
aromatic content. On the basis of the differences in fuel parameters between
Example 6 and Example 5, the EPEFE calculations would lead one to expect lower
particulate matter and NOx emissions for the fuel of Example 5.
(0049] The results shown in Table 5 below show the average difference between
the predicted reduction in emissions obtained from the EPEFE calculations and
the
observed reduction in average emissions for the fuel of Example 5 vs. the fuel
of
Example 6. Surprisingly, the data indicate that the reduction in NOx and
particulate
matter emissions achieved using the fuel compositions of the present invention
(Example 5) were substantially greater than that predicted for any of the 19
vehicles
used in the EPEFE program as well as being significantly lower than the EPEFE
fleet average. In Table 5, as in Table 7 below, negative percentages indicate
an
emissions perfomance improvement.
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Table 5
EPEFEIAutoOil predictions and actual fleet measurements for Example 5
emissions
vs. Example 6 emissions (%)
EPEFE Vehicle PM NOx
1 -5.8 -0.1
2 -7.5 -0.9
3 $~ f 0.0
f :=
s f.ss.
,.
~
4 -5 , ~ ~~
.6 ~~~~,~~~
,
5 -3.3 -1.7
6 ~, s~ -2. 5
~ ,~
~ ,:
..
7 -4.9 -1.8
8 -6.7 -1.7
9 -2.8 -1.6
10 -3.7 -0.8
11 -6.2 0.2
12 -9.5 -1.5
13 -12.0 -1.5
14 -5.0 0.0
- 15 -1.8 0.7
16 -7.5 -2.5
17 -7.3 -0.9
18 -4.0 -0.1
19 -5.4 -2.0
EPEFE fleet -10.94 -1.59
prediction
Actual result -17.44 -4.50
from
car tests
[0050] The fuel of Example 6 was also compared to another fuel of the
present invention, Example 7. Table 6 below shows the properties of these
fuels.
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Table 6
Example 6 Example 7
Sulfur (wppm) 400 14
Mono-aromatics (% wt) 19.26 20.09
Polynuclear aromatics 4.84 1.19
(% wt)
Total aromatics (% wt) 24.10 21.28
Aromatics/PNAs 5.0 17.9
Density (kg/m3) 844.1 843.0
Cetane No. 55.8 56.8
T95 (C) 337.0 336.9
[0051] The fuels were run in a single light-duty diesel vehicle with common
rail
fuel injection technology. Each fuel was tested 3 times, where a test
constituted a
cold-start legislated European type certification drive cycle (ECE+EUDC). The
relative emissions levels achieved from the Example 7 fuel tests (relative to
Example 6) were evaluated and compared with established EPEFE and AutoOil
predictions, as in the comparison between the fuels of Examples 5 and 6. The
results, shown in Table 7 below, indicate that for average particulate matter
and
NOx emissions the reduction achieved for the fuel of Example 7 was unexpected
as
it was greater than that predicted for any of the 19 vehicles used in the
EPEFE
program, as well as being significantly lower than the EPEFE fleet average.
20
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Table 7
EPEFE/Auto0il predictions and actual fleet measurements for Example 7
emissions
relative to Example 6 emissions (%)
EPEFE VehiclePM NOx
1 -4.9 1.0
2 -5.7 0.0
3 fw,E -0.1
~ ,
'
4 -2.5 = _ #~
-: ~
, ~.
.
.
-l,g _1.7
~~ ~
~~~ -2.6
Fys
6 ~~,
, ~~
. _.,
7 -2.9 -2.1
8 -3.1 -0.7
9 -0.5 -2.0
2.3 -4.5
11 -1.8 -2.5
12 -6.3 -1.1
13 -8.7 -2.0
14 -1.7 -1.5
-0.9 -0.8
16 -7.1 -4. 3
17 -6.1 -1.9
18 0.8 -1.2
19 -0.8 -3.5
EPEFE fleet -x.56 -1.13
Prediction
Actual result-20.51 -7.96
of
car tests
