U.S. patent application number 10/165462 was filed with the patent office on 2003-12-11 for aqueous additives in hydrocarbonaceous fuel combustion systems.
Invention is credited to Cunningham, Lawrence Joseph, Guinther, Gregory H., Roos, Joseph W..
Application Number | 20030226312 10/165462 |
Document ID | / |
Family ID | 29710440 |
Filed Date | 2003-12-11 |
United States Patent
Application |
20030226312 |
Kind Code |
A1 |
Roos, Joseph W. ; et
al. |
December 11, 2003 |
Aqueous additives in hydrocarbonaceous fuel combustion systems
Abstract
An aqueous additive containing a metal compound is used to
improve the operation of combustion exhaust after treatment
systems. The additive is introduced into the combustion chamber as
part of an emulsion with the fuel or, alternatively, in the
emulsion or alone as an aqueous stream introduced into the exhaust
or emission path. The metal compound scavenges combustion
byproducts in order to protect and make more efficient the after
treatment system.
Inventors: |
Roos, Joseph W.;
(Mechanicsville, VA) ; Cunningham, Lawrence Joseph;
(Mechanicsville, VA) ; Guinther, Gregory H.;
(Richmond, VA) |
Correspondence
Address: |
Ethyl Corporation
330 South Fourth Street
Richmond
VA
23219
US
|
Family ID: |
29710440 |
Appl. No.: |
10/165462 |
Filed: |
June 7, 2002 |
Current U.S.
Class: |
44/280 ; 44/301;
44/302; 44/500; 44/605; 44/606 |
Current CPC
Class: |
C10L 1/1828 20130101;
F01N 3/023 20130101; F01N 2570/14 20130101; Y02T 10/121 20130101;
Y02T 10/24 20130101; F01N 3/021 20130101; F01N 3/0293 20130101;
C10L 1/1814 20130101; F01N 3/2896 20130101; F01N 2570/04 20130101;
C10L 1/2608 20130101; C10L 1/10 20130101; C10L 10/02 20130101; C10L
1/301 20130101; C10L 1/188 20130101; F02M 25/0228 20130101; F01N
13/009 20140601; C10L 1/2227 20130101; C10L 1/2437 20130101; C10L
1/305 20130101; F01N 3/2066 20130101; F23K 5/10 20130101; C10L
1/1811 20130101; C10L 1/1266 20130101; F01N 2250/02 20130101; C10L
1/12 20130101; F01N 3/035 20130101; C10L 1/125 20130101; F01N
2430/04 20130101; Y02T 10/12 20130101; F01N 3/28 20130101; F01N
2570/08 20130101; C10L 10/06 20130101; F01N 2610/02 20130101 |
Class at
Publication: |
44/280 ; 44/301;
44/302; 44/500; 44/605; 44/606 |
International
Class: |
C10L 001/10; C10L
005/00; C10L 001/32 |
Claims
What is claimed is:
1. A hydrocarbonaceous fuel product comprising: a)
hydrocarbonaceous fuel, and b) an aqueous additive that comprises a
metal compound.
2. The fuel product of claim 1, wherein the fuel product is an
emulsion.
3. The fuel product of claim 1, wherein the aqueous additive is an
emulsion.
4. The fuel product of claim 1, wherein the metal compound is
soluble in the fuel product.
5. The fuel product of claim 1, wherein the metal compound is
dispersed in the fuel product.
6. The fuel product of claim 1, wherein the metal compound is
soluble in the aqueous additive.
7. The fuel product of claim 1, wherein the metal compound is
dispersed in the aqueous additive.
8. The fuel product of claim 1, wherein the hydrocarbonaceous fuel
is selected from gasoline, bitumen, crude oil, residual fuel oil,
bunker oils, middle distillate fuel, diesel fuel, biodiesel,
biodiesel-derived fuel, synthetic diesel fuel, coal, coal slurry,
methanol, ethanol, methane, home heating oil, lignocellulosics,
wood chips, wood pulp, sawdust, leaves, bushes, lawn clippings,
paper, urban waste, industrial waste, and farm waste, and mixtures
thereof.
9. The fuel product described in claim 1, wherein the metal
compound is an inorganic metal compound.
10. The fuel product described in claim 1, wherein the metal is
selected from the group consisting of sodium, potassium, magnesium,
calcium, barium, strontium, titanium, cerium, chromium, molybdenum,
manganese, iron, rubidium, cobalt, rhodium, nickel, palladium,
platinum, copper, silver, and mixtures thereof.
11. The fuel product described in claim 9, wherein the inorganic
metal compound is selected from the group consisting of fluorides,
chlorides, bromides, iodides, oxides, nitrates, sulfates,
phosphates, nitrides, hydrides, carbonates, and mixtures
thereof.
12. The fuel product described in claim 1, wherein the metal
compound is an organometallic compound.
13. The fuel product described in claim 6, wherein the metal is
selected from the group consisting of sodium, potassium, magnesium,
calcium, barium, strontium, titanium, cerium, chromium, molybdenum,
manganese, iron, rubidium, cobalt, rhodium, nickel, palladium,
platinum, copper, silver, and mixtures thereof.
14. The fuel product described in claim 12, wherein the
organometallic compound is selected from the group consisting of
alcohols, aldehydes, ketones, esters, anhydrides, sulfonates,
phosphonates, chelates, phenates, crown ethers, carboxylic acids,
amides, and mixtures thereof.
15. The fuel product described in claim 1, wherein the aqueous
additive is comprised of about 0.001 to about 10.0 percent by
weight of the metal compound.
16. The fuel product described in claim 1, wherein the aqueous
additive comprises about 0.001 to about 10.0 percent by weight of
the hydrocarbonaceous fuel product.
17. The fuel product described in claim 1, wherein the
hydrocarbonaceous fuel product is a liquid fuel for use in an
internal combustion engine.
18. An aqueous additive used with a hydrocarbonaceous fuel product,
wherein the additive comprises a water-soluble metal compound.
19. The aqueous additive of claim 1, wherein the aqueous additive
comprises manganese methylcyclopentadienyl tricarbonyl.
20. The aqueous additive as described in claim 18, wherein the
metal compound is an inorganic metal compound.
21. The aqueous additive as described in claim 18, wherein the
metal is selected from the group consisting of sodium, potassium,
magnesium, calcium, barium, strontium, titanium, cerium, chromium,
molybdenum, manganese, iron, rubidium, cobalt, rhodium, nickel,
palladium, platinum, copper, silver, and mixtures thereof.
22. The aqueous additive as described in claim 20, wherein the
inorganic metal compound is selected from the group consisting of
fluorides, chlorides, bromides, iodides, oxides, nitrates,
sulfates, phosphates, carbonates, nitrides, and mixtures
thereof.
23. The aqueous additive as described in claim 18, wherein the
metal compound is an organometallic compound.
24. The aqueous additive as described in claim 23, wherein the
metal is selected from the group consisting of sodium, potassium,
magnesium, calcium, barium, strontium, titanium, cerium, chromium,
molybdenum, manganese, iron, rubidium, cobalt, rhodium, nickel,
palladium, platinum, copper, silver, and mixtures thereof.
25. The aqueous additive as described in claim 23, wherein the
organometallic compound is selected from the group consisting of
alcohols, aldehydes, ketones, esters, anhydrides, sulfonates,
phosphonates, chelates, phenates, crown ethers, carboxylic acids,
amides, and mixtures thereof.
26. The aqueous additive as described in claim 18, wherein the
aqueous additive is comprised of about 0.001 to about 10.0 percent
by weight of the metal compound.
27. The aqueous additive as described in claim 18, wherein the
aqueous additive comprises about 0.001 to about 10.0 percent by
weight of the hydrocarbonaceous fuel product.
28. The aqueous additive as described in claim 18, wherein the
hydrocarbonaceous fuel product is a liquid fuel for use in a
combustion chamber.
29. An aqueous additive adapted to be injected into a
hydrocarbonaceous combustion exhaust stream, the additive
comprising a water-soluble metal compound.
30. The aqueous additive of claim 1, further comprising at least
one material selected from the group consisting of urea and
ammonia.
31. The aqueous additive as described in claim 29, wherein the
metal compound is an inorganic metal compound.
32. The aqueous additive as described in claim 29, wherein the
metal is selected from the group consisting of sodium, potassium,
magnesium, calcium, barium, strontium, titanium, cerium, chromium,
molybdenum, manganese, iron, rubidium, cobalt, rhodium, nickel,
palladium, platinum, copper, silver, and mixtures thereof.
33. The aqueous additive as described in claim 29, wherein the
inorganic metal compound is selected from the group consisting of
fluorides, chlorides, bromides, iodides, oxides, nitrates,
sulfates, phosphates, hydrides, carbonates, nitrides, and mixtures
thereof.
34. The aqueous additive as described in claim 29, wherein the
metal compound is an organometallic compound.
35. The aqueous additive as described in claim 34, wherein the
metal is selected from the group consisting of sodium, potassium,
magnesium, calcium, barium, strontium, titanium, cerium, chromium,
molybdenum, manganese, iron, rubidium, cobalt, rhodium, nickel,
palladium, platinum, copper, silver, and mixtures thereof.
36. The aqueous additive as described in claim 34, wherein the
organometallic compound is selected from the group consisting of
alcohols, aldehydes, ketones, esters, anhydrides, sulfonates,
phosphonates, chelates, phenates, crown ethers, carboxylic acids,
amides, and mixtures thereof.
37. The aqueous additive as described in claim 29, wherein the
aqueous additive is comprised of about 0.001 to about 10.0 percent
by weight of the metal compound.
38. The aqueous additive as describe in claim 29, wherein the
additive is injected into the exhaust stream at a rate of about
0.001 to about 10.0 percent by weight of the hydrocarbonaceous
source.
39. The aqueous additive as described in claim 29, wherein the
additive further comprises at least one material selected from the
group consisting of ammonia and urea.
40. A method of enhancing performance durability of a catalytic
emissions control system in a hydrocarbonaceous fuel combustion
system comprising a catalytic device having a transition metal,
noble metal, alkali or alkaline earth metal element, or
combinations thereof, said combustion system producing at least one
combustion byproduct, said method comprising: supplying a
hydrocarbonaceous fuel comprising an aqueous additive that includes
a soluble metal compound to a fuel combustion system, combusting
said fuel in said combustion system to produce at least one
byproduct, combustion complexing said metal compound with at least
one combustion byproduct, said metal compound being supplied in an
effective amount to complex with the at least one fuel combustion
byproduct, whereby the impact of said fuel combustion byproduct on
said emissions control system is reduced.
41. The method of claim 40, wherein the said fuel comprises a
spark-ignition fuel.
42. The method of claim 40, wherein said fuel comprises a
compression-ignition fuel.
43. The method of claim 40, wherein said fuel comprises a
combustion chamber fuel.
44. The method of claim 40, wherein the metal compound is an
inorganic metal compound.
45. The method of claim 40, wherein the metal is selected from the
group consisting of sodium, potassium, magnesium, calcium, barium,
strontium, titanium, cerium, chromium, molybdenum, manganese, iron,
rubidium, cobalt, rhodium, nickel, palladium, platinum, copper,
silver, and mixtures thereof.
46. The method of claim 44, wherein the inorganic metal compound is
selected from the group consisting of fluorides, chlorides,
bromides, iodides, oxides, nitrates, sulfates, phosphates,
carbonates, hydrides, nitrides, and mixtures thereof.
47. The method of claim 40, wherein the metal compound is an
organometallic compound.
48. The method of claim 47, wherein the metal is selected from the
group consisting of sodium, potassium, magnesium, calcium, barium,
strontium, titanium, cerium, chromium, molybdenum, manganese, iron,
rubidium, cobalt, rhodium, nickel, palladium, platinum, copper,
silver, and mixtures thereof.
49. The method of claim 47, wherein the organometallic compound is
selected from the group consisting of alcohols, aldehydes, ketones,
esters, anhydrides, sulfonates, phosphonates, chelates, phenates,
crown ethers, carboxylic acids, amides, and mixtures thereof.
50. The method of claim 40, wherein the aqueous additive is
comprised of about 0.001 to about 10.0 percent by weight of the
metal compound.
51. The method of claim 40, wherein the aqueous additive comprises
about 0.001 to about 10.0 percent by weight of the
hydrocarbonaceous fuel.
52. A method of enhancing performance durability of a catalytic
emissions control system for after treatment of an exhaust stream
from a hydrocarbonaceous fuel combustion system containing a
catalytic device having a transition metal, noble metal, alkali or
alkaline earth metal element, or combinations thereof, said
combustion system producing at least one byproduct, comprising:
supplying a hydrocarbonaceous fuel to a fuel combustion system,
combusting said fuel in said system to produce at least one
combustion byproduct in the exhaust stream, injecting an aqueous
additive comprising a metal compound into the exhaust stream,
complexing said metal compound with at least one combustion
byproduct, said metal compound being supplied in an effective
amount to complex with the at least one fuel combustion byproduct,
whereby performance durability of the catalytic device is
enhanced.
53. The method of claim 52, wherein the metal compound is an
inorganic metal compound.
54. The method of claim 52, wherein the metal is selected from the
group consisting of sodium, potassium, magnesium, calcium, barium,
strontium, titanium, cerium, chromium, molybdenum, manganese, iron,
rubidium, cobalt, rhodium, nickel, palladium, platinum, copper,
silver, and mixtures thereof.
55. The method of claim 53, wherein the inorganic metal compound is
selected from the group consisting of fluorides, chlorides,
bromides, iodides, oxides, nitrates, sulfates, phosphates,
hydrides, carbonates, nitrides, and mixtures thereof.
56. The method of claim 52, wherein the metal compound is an
organometallic compound.
57. The method of claim 56, wherein the metal is selected from the
group consisting of sodium, potassium, magnesium, calcium, barium,
strontium, titanium, cerium, chromium, molybdenum, manganese, iron,
rubidium, cobalt, rhodium, nickel, palladium, platinum, copper,
silver, and mixtures thereof.
58. The method of claim 56, wherein the organometallic compound is
selected from the group consisting of alcohols, aldehydes, ketones,
esters, anhydrides, carboxylic acids, sulfonates, phosphonates,
chelates, phenates, crown ethers, amides, and mixtures thereof.
59. The method of claim 52, wherein the aqueous additive is
comprised of about 0.001 to about 10.0 percent by weight of the
metal compound.
60. The method of claim 52, wherein the additive further comprises
at least one material selected from the group consisting of ammonia
and urea.
61. A catalytic emissions control system for the after treatment of
a combustion process exhaust stream, comprising: an exhaust
passageway for the passage of an exhaust stream containing exhaust
byproducts from the combustion of a hydrocarbonaceous fuel, at
least one catalytic material having catalytic activity, said
catalytic material being located within the exhaust passageway and
contacting the exhaust stream, wherein the exhaust stream contains
a water-soluble metal compound which complexes with at least one of
the exhaust byproducts and reduces the impact of the byproduct upon
the catalytic material, and wherein said fuel comprises an aqueous
additive that includes the water-soluble metal compound.
62. The system described in claim 61, wherein at least one of the
byproducts contains sulfur.
63. The system described in claim 61, wherein at least one of the
byproducts contains phosphorous.
64. The system described in claim 61, wherein at least one of the
byproducts contains a material selected from the group consisting
of lead compounds, zinc compounds, and soot.
65. A catalytic emissions control system for the after treatment of
a combustion process exhaust stream, comprising: an exhaust
passageway for the passage of an exhaust stream containing exhaust
byproducts from the combustion of a hydrocarbonaceous fuel, at
least one catalytic material having catalytic activity, said
catalytic material being located within the exhaust passageway and
contacting the exhaust stream, wherein the exhaust stream has an
aqueous additive introduced into it, the additive comprising a
water-soluble metal compound which complexes with at least one of
the exhaust byproducts and reduces the impact of the exhaust upon
the catalytic material.
66. A system as described in claim 65, wherein the additive further
comprises at least one material selected from the group consisting
of ammonia, urea, precursors thereof, or a mixture thereof.
67. The system described in claim 65, wherein at least one of the
byproducts contains sulfur.
68. The system described in claim 65, wherein at least one of the
byproducts contains phosphorous.
69. The system described in claim 65, wherein at least one of the
byproducts contains a material selected from the group consisting
of lead compounds, zinc compounds, and soot.
70. A method for protecting the catalyst in a catalytic converter
which receives combustion byproducts from the combustion of
hydrocarbonaceous fuel, said method comprising adding to the fuel
before or during combustion an aqueous additive containing a
water-soluble metal compound, whereby the catalyst is protected
relative to the catalyst in a catalytic converter which receives
combustion byproducts without said aqueous additive.
71. A method for emission reduction of one or more materials
selected from sulfur compounds, phosphorus compounds, and soot
produced by the combustion of hydrocarbonaceous fuel in a
combustion chamber, said method comprising adding to the fuel
before or during combustion an aqueous additive containing a
water-soluble metal compound, whereby the metal of said metal
compound reacts with at least one material selected from the group
consisting of sulfur, phosphorus, lead, zinc and soot to form a
particulate which is captured in a particulate trap.
72. A method for the after-treatment of combustion products
resulting from the combustion of hydrocarbonaceous materials, said
method comprising adding to the fuel before or during combustion an
aqueous additive containing a water-soluble metal compound, whereby
the metal of said metal compound reacts with at least one material
selected from the group consisting of sulfur, phosphorus, lead,
zinc and soot to form a particulate which is captured in a
particulate trap.
73. A combustion device comprising a combustion chamber, a
combustion byproduct exhaust passageway, a catalytic converter,
particulate trap, and a means for introducing an aqueous
additive.
74. A method conducted in a combustion chamber for reducing the
amount of one or more materials selected from the group consisting
of sulfur compounds, phosphorus compounds, lead compounds, zinc
compounds, and soot from combustion byproducts produced by the
combustion of a hdrocarbonaceous fuel in said combustion chamber,
the method comprising adding to the fuel before or during
combustion an aqueous additive containing a water-soluble metal
compound, whereby the metal of said metal compound reacts with at
least one material selected from the group consisting of sulfur,
phosphorus, lead, zinc and soot to form a particulate.
75. A method for reducing the amount of one or more of sulfur
compounds, phosphorus compounds, and/or soot combustion byproducts
produced from the combustion in a combustion chamber of a
hydrocarbonaceous fuel, said method occurring before the combustion
byproducts contact a catalytic converter, and comprising the steps:
adding to the fuel before or during combustion an aqueous additive
containing a water-soluble metal compound, whereby the metal of
said metal compound reacts with at least one material selected from
the group consisting of sulfur compounds, phosphorus compounds or
soot to form a particulate.
76. A composition of matter comprising a material selected from a
water-soluble metal ion source, a water-soluble metal compound, a
precursor thereof, and a mixture thereof, a water-in-fuel emulsion,
and optionally further comprising at least one component selected
from the group consisting of di-hydrocarbyl peroxides, surfactants,
dispersants, organic peroxy esters, corrosion inhibitors,
antioxidants, anti-rust agents, detergents, lubricity agents,
cyclopentadienyl manganese tricarbonyl compound, lubricity
improvers, sodium nitrite, urea, ammonium nitrate, fuel
stabilizers, and azide compounds.
77. A fuel additive comprising a metal compound, water, fuel, and
urea.
78. A fuel additive comprising a metal compound, water, fuel, and
ammonia.
79. A method for scavenging phosphorus from the combustion
byproducts resulting from the combustion of hydrocarbonaceous fuel
in a combustion chamber, said method comprising the steps of adding
to the fuel before or during combustion an aqueous additive
containing a water-soluble metal compound, whereby the metal of
said metal compound reacts with phosphorus to form a reaction
product, and removing said reaction product from said combustion
byproducts.
80. A method for scavenging sulfur from the combustion byproducts
resulting from the combustion of hydrocarbonaceous fuel in a
combustion chamber, said method comprising the steps of adding to
the fuel before or during combustion an aqueous additive containing
a water-soluble metal compound, whereby the metal of said metal
compound reacts with sulfur to form a reaction product, and
removing said reaction product from said combustion byproducts.
81. A method for scavenging soot from the combustion byproducts
resulting from the combustion of hydrocarbonaceous fuel in a
combustion chamber, said method comprising the steps of adding to
the fuel before or during combustion an aqueous additive containing
a water-soluble metal compound, whereby the metal of said metal
compound reacts with soot to form a reaction product, and removing
said reaction product from said combustion byproducts.
82. A method for preventing poisoning of a catalyst in a catalytic
converter receiving combustion byproducts from the combustion of
hydrocarbonaceous fuel in a combustion chamber, said method
comprising the steps of adding to the fuel before or during
combustion an aqueous additive containing a water-soluble metal
compound, whereby the metal of said metal compound reacts with at
least one material selected from sulfur, phosphorus, lead, zinc,
and soot to thereby prevent poisoning of the catalyst by the
sulfur, phosphorus, lead, zinc or soot.
83. A fuel composition comprising a major amount of a
hydrocarbonaceous fuel, and a minor amount of an additive
comprising the additive of claim 18.
84. The fuel product of claim 1, further comprising at least one
oxygenate selected from the group consisting of water, biodiesel,
alcohols, esters, ethers, ketones, polyols, glymes, and mixtures
thereof.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an additive for protecting
or improving operation of combustion exhaust after treatment
systems. The additive contains one or more metal compounds that are
soluble in aqueous solutions. The additive can be introduced in an
embodiment into a combustion chamber as part of an emulsion or
dispersion with the fuel, or it may be injected as the emulsion or
dispersion, or alone as an aqueous stream introduced into the
combustion exhaust. Therefore, the additive will protect emission
control devices (catalysts and traps) from degradation. In another
embodiment of the invention, the methods will reduce combustion
exhaust emissions.
DESCRIPTION OF THE PRIOR ART
[0002] It is well known in the automobile industry, or any industry
where hydrocarbonaceous fuels are burned, to reduce tailpipe (or
smokestack) emissions by using various strategies. For example, the
most common method for reducing emissions from spark ignition
engines is by careful control of the air-fuel ratio and ignition
timing. Retarding ignition timing from the best efficiency setting
reduces HC and NO.sub.x emissions, while excessive retard of
ignition increases the output of CO and HC. Increasing engine speed
reduces HC emissions, but NO.sub.x emissions increase with load.
Increasing coolant temperature tends to reduce HC emissions, but
this results in an increase in NO.sub.x emissions.
[0003] It is also known that treating the effluent stream from a
combustion process by exhaust after treatment can lower emissions.
The effluent contains a wide variety of chemical species and
compounds, some of which may be converted by a catalyst into other
compounds or species. For example, it is known to provide exhaust
after treatment including a three-way catalyst and a lean NO.sub.x
trap. Other catalytic and non-catalytic methods are also known.
[0004] Catalytic systems are capable of reducing NO.sub.x as well
as oxidizing CO and HC. However, a reducing environment for
NO.sub.x treatment is required which necessitates a richer than
chemically correct engine air-fuel ratio. A two-bed converter may
be used in which air is injected into the second stage to oxidize
CO and HC. While efficient, this procedure results in lower fuel
economy.
[0005] Single stage, three way catalysts (TWC's) are widely used,
but they require extremely precise fuel control to be effective.
Only in the close proximity of the stoichiometric ratio is the
efficiency high for all three pollutants.
[0006] Diesel compression ignition systems raise a different set of
challenges for emissions control. Strategies for reducing
particulate and HC include optimizing fuel injection and air
motion, effective fuel atomization at varying loads, control of
timing of fuel injection, minimization of parasitic losses in
combustion chambers, low sac volume or valve cover orifice nozzles
for direct injection, reducing lubrication oil contributions, and
rapid engine warm-up.
[0007] In terms of after treatment, it is known that diesel engines
generally burn lean and the exhaust will therefore usually contain
excess oxygen. Thus, NO.sub.x reduction with conventional three-way
catalysts is not feasible. NO.sub.x is removed from diesel exhaust
by either selective catalytic reduction, the use of lean NO.sub.x
catalysts such as those comprised of zeolitic catalysts or using
metals such as iridium, or catalyzed thermal decomposition of NO
into O.sub.2 and N.sub.2. It is known to use an aqueous urea
solution in selective catalyst reduction ("SCR") systems.
[0008] Diesel particulate traps have been developed which employ
ceramic or metal filters. Thermal and catalytic regeneration can
burn out the material stored. New particulate standards currently
under review may necessitate such traps. Fuel composition,
including sulfur and aromatic content, and the burning of lubricant
can contribute to increased particulate emissions. Catalysts have
been developed for diesels, which are very effective in oxidizing
the organic portion of the particulate.
[0009] Improved fuel economy can be obtained by using a lean-burn
gasoline engine, for example, a direct injection gasoline engine,
however currently NO.sub.x cannot be reduced effectively from
oxidizing exhaust using a typical three-way catalyst because the
high levels of oxygen suppress the necessary reducing reactions.
Without a NO.sub.x adsorber or lean NO.sub.x trap (LNT), the
superior fuel economy of the lean-burn gasoline engine cannot be
exploited. The function of the LNT is to scavenge the NO.sub.x from
the exhaust, retaining it for reduction at some later time. The
exhaust of both gasoline and diesel engines is net oxidizing and
therefore is not conducive to the reducing reactions necessary to
remove NO.sub.x. It is an object of the present invention to
improve the storage efficiency and durability of the LNT and to
prolong the useful life of the LNT before regeneration is
necessary.
[0010] It is well known that NO.sub.x adsorbers are highly
vulnerable to deactivation by sulfur (see, for example, M. Guyon et
al., Impact of Sulfur on NO.sub.x Trap Catalyst Activity--Study of
the Regeneration Conditions, SAE Paper No. 982607 (1998); and P.
Eastwood, Critical Topics in Exhaust Gas Aftertreatment, Research
Studies Press Ltd. (2000) pp.215-218.) and other products (e.g.,
phosphorous) resulting from fuel combustion and normal lubricant
consumption. The US Environmental Protection Agency (EPA) has set
forth proposed rules for limiting the sulfur content of highway
diesel fuels to a level of 15 parts per million (see 65 FR 35429,
Jun. 2, 2000, the complete text of which is incorporated herein by
reference). The EPA states "This proposed sulfur standard is based
on our assessment of how sulfur-intolerant advanced exhaust
emission control technologies will be."
[0011] Organometallic manganese compounds, for example
methylcyclopentadienyl manganese tricarbonyl (MMT.RTM.), available
from Ethyl Corporation of Richmond, Va., is known for use in
gasoline as both an emissions-reducing agent and as an antiknock
agent (see, e.g. U.S. Pat. No. 2,818,417). These manganese
compounds have been used to lower deposit formation in fuel
induction systems (U.S. Pat. Nos. 5,551,957 and 5,679,116),
sparkplugs (U.S. Pat. No. 4,674,447) and in exhaust systems (U.S.
Pat. Nos. 4,175,927; 4,266,946; 4,317,657, and 4,390,345.
Organometallic iron compounds, such as ferrocene, are known as well
for octane enhancement (U.S. Pat. No. 4,139,349). These additives
are all added to the hydrocarbon fuel, not to an aqueous phase or
aqueous additive.
[0012] Diesel-fueled engines produce NOx due to the relatively high
flame temperatures reached during combustion. The reduction of NOx
production can include the use of catalytic converters, using
"clean" fuels, recirculation of exhaust, and engine timing changes.
These methods are typically expensive or too complicated to be
commercially used.
[0013] It is an object of the present invention to provide fuel or
lubricant compositions capable of (1) reducing the adverse impact
of sulfur, phosphorus, soot, and other exhaust or combustion
byproducts, on emissions control technologies, including NO.sub.x
adsorbers and LNTs, and (2) reducing combustion product
emissions.
[0014] Further, the present invention provides refiners with
flexibility in complying with the objective of lowering particulate
emissions by allowing refiners to reduce sulfur to a certain level
above the regulated level, and yet still obtain the benefits of
improved exhaust emissions control technology performance obtained
by using fuels containing lower levels of sulfur.
SUMMARY OF THE INVENTION
[0015] Accordingly, it is an object of the present invention to
overcome the limitations and drawbacks of the foregoing systems and
methods to provide a composition and methods for using the
composition to protect and improve the operation of combustion
exhaust after treatment systems.
[0016] In an embodiment, the invention includes an aqueous additive
containing a water-soluble metal compound or metal ion source. The
additive may be introduced into the combustion chamber as part of
an emulsion with the fuel, or it may be injected as the emulsion,
or introduced alone as an aqueous stream into the combustion
exhaust after the combustion chamber, or introduced into the
catalytic converter.
[0017] In one embodiment, a hydrocarbonaceous fuel product
comprises a hydrocarbonaceous fuel and an aqueous additive that
comprises a water-soluble metal compound. The metal compound or
metal ion may be an inorganic metal compound or an organometallic
compound. The elemental or ionic metal can be one or more of the
following group: sodium, potassium, magnesium, calcium, barium,
strontium, titanium, cerium, chromium, molybdenum, manganese, iron,
rubidium, cobalt, rhodium, nickel, palladium, platinum, copper, and
silver compounds, and mixtures thereof. The inorganic metal
compound can be selected from the group consisting of fluorides,
chlorides, bromides, iodides, oxides, nitrates, sulfates,
phosphates, carbonates, hydrides, nitrides, and mixtures thereof.
The organometallic compound is selected from the group consisting
of alcohols, aldehydes, ketones, esters, anhydrides, sulfonates,
phosphonates, chelates, phenates, crown ethers, carboxylic acids,
amides, and mixtures thereof. Particularly useful are
organometallic compounds containing one or more carbonyl groups,
ethers or poly ethers, and other organic ligands able to coordinate
with or bond with a metal, metal compound, or metal ion.
[0018] Oxygenates are also useful in the fuel product of the
present invention including water, biodiesel, alcohols, esters,
ethers, ketones, polyols, glymes and mixtures thereof.
[0019] In a further embodiment, an aqueous additive to be used in
connection with a hydrocarbonaceous fuel product comprises a
water-soluble metal compound. As already noted herein, an additive
of the present invention may include a metal compound that is an
inorganic metal compound or an organometallic compound. The metal
is selected from the group of metals noted herein.
[0020] In the combustion of fuel or in the exhaust, the additives
of the present invention form a stable compound with combustion
byproducts, such as sulfur, phosphorus, lead, zinc or soot, which
could otherwise poison or adversely impact an after treatment
system. The stable compound formed can be readily removed from the
exhaust system by, for example, capture within a particulate
trap.
[0021] In a still further embodiment, an aqueous additive for a
hydrocarbonaceous fuel is adapted to be injected into a
hydrocarbonaceous combustion exhaust stream. The aqueous additive
contains, in an embodiment, a water-soluble metal compound.
[0022] In another embodiment of the present invention, the aqueous
additive contains a water-dispersed metal compound. The metal
compound may be an inorganic metal compound or an organometallic
compound. The metal may be selected from the group already noted
herein. The inorganic metal compounds and organometallic compounds
may also be selected from the groups already disclosed herein. The
aqueous additive may further include ammonia, urea, a precursor
thereof, or a mixture thereof.
[0023] In a still further embodiment, the invention includes a
method of enhancing performance durability of a catalytic emissions
control system in a hydrocarbonaceous fuel combustion system
containing a catalytic device. The catalytic device has a
transition metal, noble metal, alkali or alkaline earth metal
element, or combinations thereof (catalytic elements). The fuel
combustion system produces at least one combustion byproduct. The
method includes supplying a fuel comprising an aqueous additive
that includes a water-soluble metal compound to the fuel combustion
system. The metal compound complexes with at least one combustion
byproduct. The metal compound is supplied in an effective amount to
complex with at least one fuel combustion byproduct. All of the
foregoing reduce the adverse impact of the fuel combustion
byproduct on the emissions control system(s). The fuel may be, but
is not limited to, a spark-ignition fuel, a compression-ignition
fuel, or a combustion chamber fuel. The metal compound may be an
inorganic metal compound or organometallic compound as described
herein.
[0024] In a still further embodiment, the invention includes a
method of enhancing performance durability of catalytic emissions
control systems for after treatment of an exhaust stream from a
hydrocarbonaceous fuel combustion system. The fuel combustion
system contains a catalytic device having a transition metal, noble
metal, alkali or alkaline earth metal element, or combinations
thereof (catalytic elements). The combustion system produces at
least one byproduct. The method comprises injecting an aqueous
additive comprising a metal compound into the exhaust stream. The
metal compound complexes with at least one combustion byproduct.
The metal compound is supplied in an effective amount to complex
with at least one fuel combustion fuel byproduct, whereby the
impact of the byproduct on the emissions control system is reduced.
The metal compound may be an inorganic or organometallic compound.
The additive may contain ammonia, urea, precursors thereof, or a
mixture thereof.
[0025] In another embodiment, a catalytic emissions control system
for the after treatment of a combustion process exhaust stream
comprises an exhaust passageway for the passage of an exhaust
stream containing exhaust byproducts from the combustion of a
hydrocarbonaceous fuel. The system also includes at least one
catalytic material having catalytic activity, with a catalytic
material being located within the exhaust passageway and contacting
the exhaust stream. The exhaust stream contains a water-soluble
metal compound which complexes with at least one of the exhaust
byproducts and reduces the impact of the byproduct on the catalytic
material, wherein the fuel comprises an aqueous additive that
includes the water-soluble metal compound.
[0026] In another embodiment, a catalytic emissions control system
for the after treatment of a combustion process exhaust stream
comprises an exhaust passage way for the passage of an exhaust
stream containing exhaust byproducts from the combustion of a
hydrocarbonaceous fuel. The system also includes at least one
catalytic material having catalytic activity, and the catalytic
material is located within the exhaust passage way and contacts the
exhaust stream. The exhaust stream has an aqueous additive streamed
into it, the additive comprising a water-soluble metal compound
which complexes with at least one of the exhaust byproducts and
reduces the impact of the byproduct upon the catalytic
material.
DETAILED DESCRIPTION
[0027] The additives of the present invention are inorganic or
organometallic compounds metal compounds soluble or dispersable in
aqueous solutions. At least one of the metals in the additive
promotes the oxidation of carbon particulate matter. This would
include additives containing sodium, potassium, magnesium, calcium,
barium, strontium, titanium, cerium, chromium, molybdenum,
manganese, iron, rubidium, cobalt, rhodium, nickel, palladium,
platinum, copper, and silver. Upon introduction into the exhaust
stream, the metal(s) is/are released and are collected at least in
part in a particulate filter. The metal or metals come into contact
with the carbon fraction of the particulate, accelerate the carbon
oxidation reactions, and aid in particulate trap regeneration. The
exhaust system may contain other aftertreatment systems in addition
to the particulate filter.
[0028] The hydrocarbonaceous fuel combustion systems that may
benefit from the present invention include all internal combustion
engines that burn, for example, gasoline, diesel, or similar type
fuels. It also refers to coal-burning power plants, wood-burning
cogeneration plants, waste burners, burner operations, or any other
combustion of a hydrocarbonaceous fuel product. By "combustion
chamber" herein is meant any and all devices, machines, engines,
incinerators, stationary burners and the like which can combust or
in which can be combusted a hydrocarbonaceous fuel. Thus, by
"hydrocarbonaceous fuel" herein is meant one or more fuels selected
from the group consisting of gasoline, bitumen, crude oil, residual
fuel oil, bunker oils, middle distillate fuel, diesel fuel,
biodiesel, biodiesel-derived fuel, synthetic diesel fuel, coal,
coal slurry, methanol, ethanol, methane, home heating oil,
lignocellulosics, wood chips, wood pulp, sawdust, leaves, bushes,
lawn clippings, paper, urban waste, industrial waste, and farm
waste, and mixtures thereof.
[0029] Conventional combustion systems will typically include some
degree of emission control. In all cases of combustion, the
emission treatment may include a catalytic system to reduce harmful
emissions. Of course, other emission treatment systems are well
known.
[0030] Unfortunately, such emission systems have a tendency to lose
their effectiveness over time due to poisoning or degradation of
emission treatment system components.
[0031] The present invention contemplates providing a metal
compound to an aqueous solution as an additive to a fuel or
lubricant composition or, alternatively, directly into the exhaust
stream or combustion zone resulting from the combustion process,
whereby the useful life of the emission treatment system components
will be significantly improved.
[0032] Preferred metals herein include elemental and ionic sodium,
potassium, magnesium, calcium, barium, strontium, titanium, cerium,
chromium, molybdenum, manganese, iron, rubidium, cobalt, rhodium,
nickel, palladium, platinum, copper and silver, precursors thereof,
and mixtures. These metal compounds may be either inorganic or
organic. Also effective in the present invention is the generation,
liberation or production in situ of one or more of these metals or
metal ions.
[0033] Preferred inorganic metallic compounds in an embodiment of
the present invention can include by example and without limitation
methylcyclopentadienyl manganese tricarbonyl (MMT.RTM. available
from Ethyl Corporation), sodium chloride, potassium chloride,
titanium dioxide, copper oxide, sodium nitrates, sodium nitrites,
and copper and silver halides. Metallic sulfates and metallic
phosphates will be operative in the present invention and may, in
certain fuels and combustion applications, not present unacceptable
additional sulfur and phosphorus combustion byproducts.
[0034] Preferred organometallic compounds in an embodiment of the
present invention include alcohols, aldehydes, ketones, esters,
anhydrides, carboxylic acids and amides. In each of the foregoing
alternatives, the metal compound is soluble in water. By "soluble
in water" or "water dispersed" herein is meant any amount of metal
compound dissolved in, dissolvable in, or dispersed in any volume
of water. No limitation is known with regard to the solubility or
dispersability of the metal compounds effective in the present
invention.
[0035] In another embodiment, the metal compound is delivered to
the combustion chamber or to the combustion exhaust stream through
the organic phase of a fuel emulsion or hydrocarbonaceous fuel.
[0036] In an embodiment, when formulating aqueous additives of the
present invention, the metal compounds are employed in amounts
sufficient to reduce the impact of poisons, e.g., sulfur, lead,
soot and phosphorus, on the emissions control systems. Still
further, the metallic compounds are employed in amounts sufficient
to reduce combustion emissions all together. Generally speaking,
the aqueous additive of the invention will contain an amount of the
metal compound, ion or precursor thereof sufficient to provide from
about 0.001 grams to about 2.0 grams of metal or metal compound per
liter of fuel (in the case of a liquid fuel product), and
preferably from about 0.01 grams to about 1.0 grams of metal or
metal compound per liter of fuel.
[0037] In another embodiment, hydrocarbonaceous fuel can include
methane gas that is used, for example, alone or in conjunction with
other fuels in an internal combustion engine. Ethanol, methanol and
other alcohols, as well as esters, ethers, ketones, polyols, glymes
and other oxygenates are also useful herein as hydrocarbonaceous
fuels to which the water-soluble metal compounds can be added for
beneficial emission and catalysis results.
[0038] In yet another embodiment, farm waste including fodder,
silage, field and crop residue, animal excrement, and other
bioproducts can be utilized as a fuel herein with or without the
addition of process aids. To such waste can be added the
water-soluble metal compounds of the present invention.
[0039] With respect to other types of solid hydrocarbonaceous fuel
products such as coal, lignocellulosics (including wood chips,
sawdust, leaves, bushes, lawn clippings, and paper), and
combustible urban, industrial or farm waste, the aqueous additive
will contain an amount of the metal compound sufficient to provide
about 0.001 grams to about 10.0 grams of metal per 100 grams of the
solid fuel, preferably about 0.01 to about 1.0 grams of metal per
100 grams of the solid fuel.
[0040] When the metal is added to the lubrication systems of
combustion systems as a means of delivering the metal to the
combustion system, the metal concentration may be increased to
provide the above amounts of metal in the combustion chamber. In
this embodiment, it is known that all internal combustion engines
burn some lubricant thereby adding to the combustion byproducts any
material carried into the combustion chamber by the lubricant.
[0041] While not being bound by the following theory, it is
postulated that the sulfur or phosphorus or other possible
combustion byproducts in the emission system react with the metal
or metal ion in the present invention to form a metal sulfate or
phosphate (MSO.sub.4 and MPO.sub.4) which is stable in the
temperature range of 200-650.degree. C. Surprisingly, metal
sulfates such as, for instance, MnSO.sub.4, do not bind to active
sites on the catalyst of automotive emission systems, whereas free
sulfur often does, thereby poisoning the catalyst.
[0042] When the emissions system contains a component which is
poisionable by combustion byproducts (such as sulfur, phosphorus,
lead, zinc or soot), for instance, a barium-containing lean
NO.sub.x trap, the present invention provides novel compositions
and methods for providing a substance which competes with the
active site (e.g., barium) in the lean-burning exhaust. As long as
the metal of the scavenging agent will compete with the metal of
the catalyst system for complexing with the potential emissions
system poisons (e.g., sulfur) the metals may be suitable for use as
scavenging agents. The ability of the metal scavenging agent to
compete with the metals of the catalyst for complexing with the
catalyst poisons can be determined by monitoring catalyst
durability. Further, the metal scavengers of the present invention
can reduce the detrimental impact of other poisons such as sulfur,
phosphorous, lead, zinc, or soot on emissions control systems of
the lean burn combustion systems in one embodiment of the present
invention.
[0043] The addition of some metal compounds in the combustion of
fuel products is known generally in the context of fuel-soluble
additives. In the present invention, the metal additive can be
water-soluble or dispersable and delivered through an aqueous
additive to obtain comparable emissions aftertreatment benefits.
Yet, the use of the aqueous additive is beneficial in its ease of
handling, expense, ease of preparation, etc. and can be used herein
in addition to fuel soluble additives.
[0044] In addition to the beneficial compositions of matter noted
herein, there are corollary methods of using the described aqueous
additive to enhance the performance and durability of emissions and
aftertreatment systems. The instance of incorporating the additive
to the fuel to form an emulsion (gasoline, diesel, etc.),
dispersion, suspension, or slurry (coal, etc.) can have positive
benefits on the emissions from the combustion. The additive may
also be injected alone or with liquid fuel directly into the
exhaust stream of a combustion process.
EXAMPLE 1
[0045] 1. The additives are inorganic or organometallic compounds
metal compounds soluble in aqueous solutions. At least one of the
metals in the additive promotes the oxidation of carbon particulate
matter. This would include additives containing elemental or ionic
sodium, potassium, magnesium, calcium, barium, strontium, titanium,
cerium, chromium, molybdenum, manganese, iron, rubidium, cobalt,
rhodium, nickel, palladium, platinum, copper and silver. Upon
introduction into the exhaust stream, the metal(s) is (are)
released and collected, at least in part, in a particulate filter.
The metals come into contact with the carbon fraction of the
particulate, accelerate the carbon oxidation reactions, and aid in
particulate trap regeneration. The exhaust system may contain other
aftertreatment systems in addition to the particulate filter.
EXAMPLE 2
[0046] In one application the exhaust system contains at least a
particulate trap upstream of a selective catalytic reduction (SCR)
system, which is designed to aid in the reduction of exhaust
NO.sub.x emissions. The SCR utilizes in one embodiment urea as a
reductant. Urea is typically a solid but to ease handling an
aqueous solution, preferably at a concentration of about 32.5% can
be used. This solution can form a eutectic with a low
crystallization point (-110.degree. C.). In case of
crystallization, the eutectic mixture provides an aqueous and solid
phase of equal composition. The additive is added to this
solution.
[0047] The urea/additive aqueous solution is, in one embodiment,
injected into the exhaust stream after the exhaust stream has left
the combustion chamber. The water is vaporized and the urea
decomposes to form ammonia (NH.sub.3), which reacts with oxides of
nitrogen over a catalyst to form N.sub.2 and H.sub.2O. Upon
evaporation of the water, the metal from the additive is released
and collected with the combustion particulate matter in the
particulate trap. The metal increases particulate oxidation,
thereby promoting trap regeneration.
[0048] By introducing the particulate trap regeneration additive
with the reductant in this system, its presence in the particulate
trap is assured. A separate additive-dosing tank on the vehicle, as
used in some cases (Peugeot) is not needed. Enhanced regeneration
does not rely on additive being present in fuel.
EXAMPLE 3
[0049] In the application described in Example 2, the metal
additive used is one that will form stable metal phosphates. A
portion of the metal released in the exhaust interacts to form
stable metal phosphates as solid particulate and prevent phosphorus
deposition on exhaust catalyst. The use of these additives will
protect the SCR catalyst from deterioration due to phosphorus
poisoning.
EXAMPLE 4
[0050] Two of the primary factors that determine the extent to
which the reaction between NH.sub.3 and oxides of nitrogen proceed
to completion is the surface areas of catalyst available to
catalyst the reaction and the amount of time the reactants and
catalyst spend together an optimal temperatures for reaction.
[0051] In the application described in Example 2, the metal
additive may be chosen such that at least one of the metals
catalyzes the reaction between NH.sub.3 and NO. The metal additive
will form very small metal cluster in the exhaust and possess high
specific surface area. The high surface area available on the nano
sized catalytic sites provided by the metal additive will provide
additional activity for NO conversion. Also, the reactants will
move with the catalyst through the exhaust stream, increasing
residence time in contact with the catalyst. The presence of the
catalyst in the exhaust will also help insure that catalyst and
reactants are together at optimal conversion temperatures for
oxides of nitrogen. The ability to have catalyst present at the
time optimal reaction temperatures are reached is advantageous over
relying on a catalyst fixed in the exhaust system. This catalyst
would be amenable to wide swings in exhaust temperatures occur
during transient engine operation.
EXAMPLE 5
[0052] A fuel water emulsion in which the aqueous phase
additionally contains a water-soluble additive containing 0.05
weight percent of a divalent Mn compound is used in a diesel
engine. The diesel engine operates under fuel lean conditions. Upon
combustion of the fuel, the water-soluble manganese additive
decomposes to form primarily manganese oxides. Sulfur oxides in the
exhaust gas interact with the manganese oxides to form stable
manganese sulfate, scavenging the SO.sub.2 and SO.sub.3 from the
exhaust as solid particles are captured in the particulate trap or
emitted from the exhaust.
EXAMPLE 6
[0053] A fuel water emulsion in which the aqueous phase
additionally contains a water-soluble additive containing 0.05
weight percent of a manganese compound is used in a diesel engine.
The diesel engine operates under fuel lean conditions. Upon
combustion of the fuel, the water-soluble manganese additive
decomposes to form primarily manganese oxides. Sulfur oxides in the
exhaust gas interact with the manganese oxide to form stable
manganese sulfate scavenging the SO.sub.2 and SO.sub.3 from the
exhaust. The manganese oxides effectively tie up the phosphorus in
a stable compound and reduce the phosphorus deposition on catalyst
systems in the exhaust. In addition the water-soluble manganese
compound will aid in the regeneration of a particulate trap if one
is present.
[0054] Embodiments of the present invention include a method of
enhancing performance durability of a catalytically-based emissions
control system in a lean fuel combustion system containing a
catalytic device having a transition metal, alkali or alkaline
earth metal element, or combinations thereof (catalytic elements),
said combustion system producing at least one byproduct, comprising
supplying a fuel to said lean fuel combustion system, said
combustion system being provided with a scavenger, said scavenger
complexing with at least one combustion byproduct, said scavenger
being supplied in an effective amount to complex with the at least
one fuel combustion byproduct, whereby the impact of said fuel
combustion byproduct on said emissions control system is
reduced.
[0055] It is to be understood that the reactants and components
referred to by chemical name anywhere in the specification or
claims hereof, whether referred to in the singular or plural, are
identified as they exist prior to coming into contact with another
substance referred to by chemical name or chemical type (e.g., base
fuel, solvent, etc.). It matters not what chemical changes,
transformations and/or reactions, if any, take place in the
resulting mixture or solution or reaction medium as such changes,
transformations and/or reactions are the natural result of bringing
the specified reactants and/or components together under the
conditions called for pursuant to this disclosure. Thus the
reactants and components are identified as ingredients to be
brought together either in performing a desired chemical reaction
(such as formation of the organometallic compound) or in forming a
desired composition (such as an additive concentrate or additized
fuel blend). It will also be recognized that the additive
components can be added or blended into or with the base fuels
individually per se and/or as components used in forming preformed
additive combinations and/or sub-combinations. Accordingly, even
though the claims hereinafter may refer to substances, components
and/or ingredients in the present tense ("comprises", "is", etc.),
the reference is to the substance, components or ingredient as it
existed at the time just before it was first blended or mixed with
one or more other substances, components and/or ingredients in
accordance with the present disclosure. The fact that the
substance, components or ingredient may have lost its original
identity through a chemical reaction or transformation during the
course of such blending or mixing operations is thus wholly
immaterial for an accurate understanding and appreciation of this
disclosure and the claims thereof.
[0056] At numerous places throughout this specification, reference
has been made to a number of U.S. patents and published foreign
patent applications. All such cited documents are expressly
incorporated in full into this disclosure as if fully set forth
herein.
[0057] This invention is susceptible to considerable variation in
its practice. Therefore the foregoing description is not intended
to limit, and should not be construed as limiting, the invention to
the particular exemplifications presented hereinabove. Rather, what
is intended to be covered is as set forth in the ensuing claims and
the equivalents thereof permitted as a matter of law.
[0058] Patentee does not intend to dedicate any disclosed
embodiments to the public, and to the extent any disclosed
modifications or alterations may not literally fall within the
scope of the claims, they are considered to be part of the
invention under the doctrine of equivalents.
* * * * *