U.S. patent application number 10/868126 was filed with the patent office on 2005-12-15 for ultra-fine particle catalysts for carbonaceous fuel elements.
Invention is credited to Banerjee, Chandra Kumar, Cash, Sheila Lynnette, Chung, Henry Hsiao Liang, Sears, Stephen Benson.
Application Number | 20050274390 10/868126 |
Document ID | / |
Family ID | 35355344 |
Filed Date | 2005-12-15 |
United States Patent
Application |
20050274390 |
Kind Code |
A1 |
Banerjee, Chandra Kumar ; et
al. |
December 15, 2005 |
Ultra-fine particle catalysts for carbonaceous fuel elements
Abstract
The present invention provides fuel elements comprising a
carbonaceous material and a catalyst composition comprising
ultrafine particles of a metal oxide and/or metal. The present
invention additionally provides smoking articles demonstrating
reduced amounts of carbon monoxide in the smoke-like aerosol
produced by the smoking article. In a further aspect, the present
invention provides methods and apparatus for the simultaneous
resolution and quantification of a carbon monoxide content and a
carbon dioxide content of a gaseous mixture.
Inventors: |
Banerjee, Chandra Kumar;
(Clemmons, NC) ; Sears, Stephen Benson; (Siler
City, NC) ; Cash, Sheila Lynnette; (Greensboro,
NC) ; Chung, Henry Hsiao Liang; (Advance,
NC) |
Correspondence
Address: |
J. Clinton Wimbish
Kilpatrick Stockton LLP
1001 West Fourth Street
Winston-Salem
NC
27101
US
|
Family ID: |
35355344 |
Appl. No.: |
10/868126 |
Filed: |
June 15, 2004 |
Current U.S.
Class: |
131/334 ;
131/342 |
Current CPC
Class: |
G01N 30/7206 20130101;
A24B 15/287 20130101; B01J 35/0013 20130101; A24D 1/22 20200101;
A24B 15/288 20130101; B01J 23/52 20130101; A24B 15/165 20130101;
B01J 23/745 20130101; G01N 30/466 20130101; B01J 21/063 20130101;
B01J 23/10 20130101; A24B 15/286 20130101 |
Class at
Publication: |
131/334 ;
131/342 |
International
Class: |
A24D 003/04; A24D
003/08 |
Claims
What is claimed is:
1. A fuel element comprising: a carbonaceous material; and at least
one catalyst composition comprising ultrafine particles of a metal
oxide, metal, or mixtures thereof.
2. The fuel element of claim 1, wherein the metal oxide comprises
ferric oxide.
3. The fuel element of claim 1, wherein the metal comprises gold,
copper, silver, platinum, palladium, rhodium, nickel, and mixtures
thereof.
4. The fuel element of claim 1, wherein the catalyst composition
comprises up to 5% by weight of the fuel element.
5. The fuel element of claim 1 wherein the ultrafine particles have
an individual particle size up to about 1 micrometer.
6. The fuel element of claim 1, wherein the ultrafine particles
have an individual particle size of up to about 5 nanometers.
7. The fuel element of claim 1, wherein the ultrafine particles
have an individual particle size between about 2 and about 4
nanometers.
8. A smoking article comprising: a fuel element comprising a
carbonaceous material and at least one catalyst composition
comprising ultrafine particles of a metal oxide, metal, or mixtures
thereof; and a physically separate aerosol generating means
comprising at least one aerosol forming material.
9. The smoking article of claim 8 wherein the metal oxide comprises
ferric oxide.
10. The smoking article of claim 8, wherein the catalyst
composition is operable to convert carbon monoxide to carbon
dioxide at temperatures between about 700.degree. C. and about
950.degree. C.
11. A method for reducing carbon monoxide production of a fuel
element comprising: incorporating a catalyst composition into the
fuel element, the catalyst composition comprising: ultrafine
particles of a metal oxide, metal, or mixtures thereof.
12. The method of claim 11, wherein incorporating a catalyst
composition into the fuel element comprises wash coating, dipping,
painting, or spraying the fuel element with the catalyst
composition.
13. The method of claim 11, wherein incorporating a catalyst
composition into the fuel element comprises placing the catalyst
composition in an inner core of the fuel element wherein the inner
core is surrounded by an outer shell comprising carbonaceous
material.
14. The method of claim 11, wherein incorporating a catalyst
composition into a fuel element comprises placing the catalyst
composition on a substrate located behind the fuel element.
15. The method of claim 14, wherein the substrate comprises an
inert carbon material or a porous material.
16. A method for simultaneously quantifying a carbon monoxide
content and a carbon dioxide content of a gaseous mixture
comprising: injecting the gaseous mixture into a split single
injector of a gas chromatogram; resolving the carbon monoxide
content of the gaseous mixture on a first chromatographic column
and simultaneously resolving the carbon dioxide content of the
gaseous mixture on a second chromatographic column; and detecting
and quantifying the resolved carbon monoxide content and carbon
dioxide content with a mass spectrometer.
17. The method of claim 16, wherein the gaseous mixture comprises
smoke from a smoking article, mainstream smoke from a smoking
article, smoke-like aerosol from a smoking article, or mixtures
thereof.
18. An apparatus for simultaneously quantifying a carbon monoxide
content and a carbon dioxide content of a gaseous mixture
comprising: a gas chromatograph comprising a split single injector
and two chromatographic columns; and a mass spectrometer.
19. The apparatus of claim 18, wherein one of the chromatographic
columns possesses the ability to resolve carbon monoxide from a
gaseous mixture, and the remaining chromatographic column possesses
the ability to resolve carbon dioxide from a gaseous mixture.
20. The apparatus of claim 18, wherein the temperature of the split
single injector of the gas chromatograph is variable.
Description
Field of the Invention
[0001] The present invention relates generally to fuel elements for
smoking articles, and more particularly to fuel elements comprising
a carbonaceous material and ultrafine particles. In an embodiment,
the fuel elements may be utilized in smoking articles to reduce the
amount of carbon monoxide in the mainstream smoke and improve the
thermal efficiency of the fuel.
BACKGROUND OF THE INVENTION
[0002] Cigarettes are popular smoking articles that use tobacco in
various forms. Descriptions of cigarettes and the various
components thereof are set forth in Tobacco Production, Chemistry
and Technology, Davis et al. (Eds.) (1999).
[0003] Cigarettes generally include a substantially cylindrical
rod-shaped structure and include a charge, roll or column of
smokeable material such as shredded tobacco (e.g., in cut filler
form) surrounded by a paper wrapper thereby forming a so-called
"tobacco rod." Normally, a cigarette has a cylindrical filter
element aligned in an end-to-end relationship with the tobacco rod.
Typically, a filter element includes cellulose acetate tow
circumscribed by plug wrap, and is attached to the tobacco rod
using a circumscribing tipping material. It also has become
desirable to perforate the tipping material and plug wrap, in order
to provide dilution of drawn mainstream smoke with ambient air.
[0004] Carbonaceous materials can be employed as components of
combustible material components in a smoking article that are
designed to burn and provide heat to aerosolize physically separate
aerosol-forming materials. Cigarettes having carbonaceous
combustible material components have been marketed by the R. J.
Reynolds Tobacco Company under the tradenames Premier and Eclipse.
See, for example, U.S. Pat. No. 4,708,151 to Shelar et al.; U.S.
Pat. No. 5,016,654 to Bernasek et al.; U.S. Pat. No. 4,991,596 to
Lawrence et al.; U.S. Pat. No. 5,038,802 to White et al.; U.S. Pat.
No. 4,793,365 to Sensabaugh et al.; U.S. Pat. No. 4,961,438 to
Korte; U.S. Pat. No. 4,991,606 to Serrano et al.; U.S. Pat. No.
5,020,548 to Farrier et al.; U.S. Pat. No. 5,076,297 to Farrier et
al.; U.S. Pat. No. 5,148,821 to Best et al.; U.S. Pat. No.
5,178,167 to Riggs et al.; U.S. Pat. No. 5,183,062 to Clearman et
al.; U.S. Pat. No. 5,345,955 to Clearman et al.; U.S. Pat. No.
5,551,451 to Riggs et al.; and U.S. Pat. No. 5,595,577 to Bensalem
et al. The disclosure of each of these patents is incorporated
herein by reference. See, also, Chemical and Biological Studies on
New Cigarette Prototypes that Heat Instead of Burn Tobacco, R. J.
Reynolds Tobacco Company Monograph (1988).
[0005] It also has been suggested to incorporate non-combustible
materials into the carbonaceous combustible material components of
certain types of smoking articles. See, for example, U.S. Pat. No.
5,040,551 to Schlatter et al.; U.S. Pat. No. 5,211,684 to Shannon
et al.; U.S. Pat. No. 5,240,014 to Deevi et al.; and U.S. Pat. No.
5,258,340 to Augustine et al. The disclosure of each of these
patents is incorporated herein by reference.
[0006] It would be desirable to provide a fuel element for a
smoking article that reduces the amount of carbon monoxide present
in the aerosol of the smoking article. It would additionally be
desirable to provide a fuel element that displays a more efficient
combustion.
SUMMARY OF THE INVENTION
[0007] The present invention provides fuel elements comprising
ultrafine particles. In an embodiment of the present invention, the
ultrafine particles catalyze the conversion of carbon monoxide to
carbon dioxide, thereby reducing the amount of carbon monoxide
present in the combustion gases produced by burning of the fuel
element. In a smoking article embodiment, a fuel element comprising
ultrafine particles reduces the amount of carbon monoxide present
in the aerosol and demonstrates a more efficient combustion by
producing more energy per gram of fuel combusted.
[0008] The present invention also provides methods for altering the
performance characteristics of smoking articles to reduce the
amount of carbon monoxide present in aerosol produced by the
smoking article.
[0009] In one aspect, the present invention provides a fuel element
comprising a carbonaceous material and at least one catalyst
composition, the catalyst composition comprising ultrafine
particles.
[0010] In another aspect, the present invention provides a method
for reducing the amount of carbon monoxide produced by an article
comprising a fuel element, the method comprising incorporating
ultrafine particles in the fuel element.
[0011] In a further aspect, the present invention provides a
smoking article having reduced amounts of carbon monoxide in the
aerosol produced by the smoking article. In an embodiment, the
smoking article comprises: a fuel element comprising a carbonaceous
material and ultrafine particles.
[0012] In a still further aspect, the present invention provides
methods and apparatus for the simultaneous relative quantification
of carbon monoxide and carbon dioxide in a gaseous mixture. In an
embodiment, the method comprises injecting a gaseous mixture into a
split single injector of a gas chromatograph for splitting the
gaseous mixture onto two chromatographic columns; resolving the
carbon monoxide content of the gaseous mixture on a first
chromatographic column; simultaneously resolving the carbon dioxide
content of the gaseous mixture on a second chromatographic column;
and detecting and quantifying the resolved carbon monoxide and
carbon dioxide contents with a mass spectrometer. Embodiments of
the method may be utilized to simultaneously quantify the relative
amounts of carbon monoxide and carbon dioxide in aerosol from a
smoking article.
[0013] An advantage of the present invention is that that fuel
elements of the present invention may be used in applications where
it is desirable to reduce amounts of carbon monoxide.
[0014] Further features and advantages of the present invention are
set forth in the following more detailed description.
BRIEF DESCRIPTION OF THE FIGURES
[0015] FIG. 1 illustrates a smoking article according to an
embodiment of the present invention.
[0016] FIG. 2 illustrates a method according to an embodiment of
the present invention.
[0017] FIG. 3 illustrates an apparatus according to an embodiment
of the present invention.
[0018] FIG. 4 illustrates an ion chromatogram of a standard gaseous
mixture resolved on dual columns according to an embodiment of the
present invention.
[0019] FIG. 5 illustrates an ion chromatogram of a standard gaseous
mixture resolved on a Molsieve column according to an embodiment of
the present invention.
[0020] FIG. 6 illustrates an ion chromatogram of a standard gaseous
mixture resolved on a Carbon Plot column according to an embodiment
of the present invention.
[0021] FIG. 7 illustrates an ion chromatogram of heated tobaccos
resolved on dual columns according to an embodiment of the present
invention.
[0022] FIG. 8 illustrates an ion chromatogram of cigarette smoke
resolved on dual columns according to an embodiment of the present
invention.
[0023] FIG. 9 illustrates the reduced production of carbon monoxide
by carbon upon combustion in the presence of various ultrafine
particles according to embodiments of the present invention.
[0024] FIG. 10 illustrates the reduced production of carbon
monoxide by combustion of carbon and mixtures comprising carbon,
Guar gum, graphite, and tobacco in the presence of iron oxide
ultrafine particles of various sizes according to embodiments of
the present invention.
[0025] FIG. 11 illustrates the reduced production of carbon
monoxide by combustion of carbon in the presence of various metal
oxide ultrafine particles according to embodiments of the present
invention.
[0026] FIG. 12 illustrates the effect of catalyst compositions on a
CO/CO.sub.2 ratio when tobacco is pyrolized in the presence of
various ultrafine particles according to embodiments of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The present invention provides fuel elements comprising a
carbonaceous material and at least one catalyst composition. The
present invention additionally provides articles of manufacture
including, but not limited to, smoking articles. The present
invention further provides methods for altering the performance
characteristics of smoking articles. Moreover, the present
invention provides methods and apparatus for the simultaneous
quantification of the carbon monoxide content and carbon dioxide
content of a gaseous mixture comprising these and various other
chemical species.
[0028] Reference is made below to specific embodiments of the
present invention. Each embodiment is provided by way of
explanation of the invention, not as a limitation of the invention.
In fact, it will be apparent to those skilled in the art that
various modifications and variations can be made in the present
invention without departing from the scope or spirit of the
invention. For instance, features illustrated or described as part
of one embodiment may be incorporated into another embodiment to
yield a further embodiment. Thus, it is intended that the present
invention cover such modifications and variations as come within
the scope of the appended claims and their equivalents.
[0029] For the purposes of this specification, unless otherwise
indicated, all numbers expressing quantities of ingredients,
reaction conditions, and so forth used in the specification are to
be understood as being modified in all instances by the term
"about." Accordingly, unless indicated to the contrary, the
numerical parameters set forth in the following specification are
approximations that can vary, depending upon the desired properties
sought to be obtained by the present invention. At the very least,
and not as an attempt to limit the application of the doctrine of
equivalents to the scope of the claims, each numerical parameter
should at least be construed in light of the number of reported
significant digits and by applying ordinary rounding
techniques.
[0030] Notwithstanding that the numerical ranges and parameters
setting forth the broad scope of the invention are approximations,
the numerical values set forth in the specific examples are
reported as precisely as possible. Any numerical value, however,
inherently contains certain errors necessarily resulting from the
standard deviation found in their respective testing measurements.
Moreover, all ranges disclosed herein are to be understood to
encompass any and all subranges subsumed therein, and every number
between the end points. For example, a stated range of "1 to 10"
should be considered to include any and all subranges between (and
inclusive of) the minimum value of 1 and the maximum value of 10;
that is, all subranges beginning with a minimum value of 1 or more,
e.g., 1 to 6.1, and ending with a maximum value of 10 or less,
e.g., 5.5 to 10, as well as all ranges beginning and ending within
the end points, e.g., 2 to 9, 3 to 8, 3.2 to 9.3, 4 to 7, and
finally to each number 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 contained
within the range. Additionally, any reference referred to as being
"incorporated herein" is to be understood as being incorporated in
its entirety.
[0031] It is further noted that, as used in this specification, the
singular forms "a," "an," and "the" include plural referents unless
expressly and unequivocally limited to one referent.
[0032] In one embodiment of the present invention, a fuel element
comprises a carbonaceous material and at least one catalyst
composition. The catalyst composition comprises ultrafine particles
of a metal oxide, metal, or mixtures thereof. As used herein, the
term ultrafine particle is generally used to indicate particles
with dimensions less than 100 nanometers (one nanometer is
one-billionth of a meter). The metal oxide and metal ultrafine
particles can demonstrate activity for catalyzing chemical
reactions, such as the oxidation of carbon monoxide to carbon
dioxide.
[0033] Ultrafine particles suitable for use in catalytic
compositions of the present invention comprise, but are not limited
to, iron oxides (e.g. FeO, Fe.sub.2O.sub.3 and Fe.sub.3O.sub.4),
gold, copper, silver, platinum, palladium, rhodium, nickel, zinc,
zirconium, other transition metals, metal oxides, and mixtures
thereof.
[0034] The catalyst compositions comprising ultrafine particles
facilitate a more complete production of carbon dioxide by
catalyzing the oxidation reaction of carbon to carbon dioxide. In
an embodiment wherein combustion of a fuel element generates a
gaseous stream comprising carbon monoxide, the catalyst composition
acts upon carbon monoxide in the gaseous stream. Ultrafine
particles of the catalyst compositions may also improve the
performance characteristics of a fuel element for particular
applications. For example, the ultrafine particles of the catalyst
compositions can increase the caloric output of a particular
fuel.
[0035] In an embodiment of the present invention, ultrafine
particles of the catalyst compositions may have an average particle
size of 10 nanometers, generally between 1 nanometer and 1 micron.
In an embodiment of a smoking article of the present invention, the
ultrafine particles may have an individual particle size of up to
about five nanometers. In another embodiment of a smoking article
of the present invention, the ultrafine particles may have an
individual particle size between about two and four nanometers.
[0036] Ultrafine particles according to the present invention may
be produced by a variety of methods including sol-gel synthesis,
chemical deposition, deposition precipitation, inert gas
condensation, mechanical alloying or high-energy ball milling,
plasma synthesis, and electrodeposition. Using such methods,
ultrafine particles can be produced in various symmetric shapes,
such as spheres, cylinders, prisms, cubes, tetrapods and amorphous
clusters. In embodiments of the present invention, the physical
properties of the ultrafine particles, including for example, their
electrical, optical, chemical, mechanical, and magnetic properties,
may be selectively controlled for example by engineering the size,
morphology, and/or composition of the ultrafine particles. The
resulting materials may have enhanced or entirely different
properties from their parent materials.
[0037] Representative types of ultrafine particles and materials
for use in the present invention are of the type, and may be
produced by methods, described in U.S. Pat. No. 6,503,475 to
McCormick U.S. Pat. No. 6,472,459 to Morales et al., U.S. Pat. No.
6,467,897 to Wu et al., U.S. Pat. No. 6,479,146 to Caruso et al.,
and U.S. Pat. No. 6,479,156 to Schmidt et al. and U.S. Published
Pat. Applications 2002/0194958 to Lee et al., 2002/014453 to Lilly
Jr., et al., 2003/0000538 to Bereman et al., 2002/0167118,
2002/0172826 and 2002/0127351, the disclosure of each patent and
published application being incorporated herein by reference.
[0038] Ultrafine particles for use in the catalyst composition can
be obtained commercially. For example, Superfine Iron oxide
(Fe.sub.2O.sub.3) can be obtained from MACH-1 Inc. of King of
Prussia, Pa. Nanopowder Enterprise Inc. of Piscataway, N.J. is an
additional commercial source of ultrafine particles for use in
catalyst compositions of the present invention.
[0039] In embodiments of the present invention, the fuel element
additionally comprises a carbonaceous material. The fuel element
may additionally comprise binders like Guar gum, other metallic
particles such as aluminum or the like, inert filler material like
graphite, and/or burn modifiers such as sodium or potassium
carbonate. In some embodiments, the carbonaceous materials for use
in the fuel element include at least 50%, by weight carbon. In
other embodiments the carbonaceous materials for use in the fuel
element can include about 60-95% by weight carbon. In still further
embodiments, the carbonaceous materials for use in the fuel element
can include about 70-80% by weight carbon. The carbonaceous
materials may be in powder form and may be partially activated. The
carbonaceous materials may also be heat treated. The carbonaceous
materials may comprise organic carbon containing materials, for
example tobacco.
[0040] The carbonaceous materials of the present invention may be
prepared from several starting materials. Suitable starting
materials include, but are not limited to, cellulosic materials
with a high (i.e., greater than about 80%) alpha-cellulose content,
such as cotton, rayon, paper, and the like. The carbonaceous
materials of fuel elements of the present invention may be
generally prepared by pyrolysis of the starting material at a
temperature between about 400.degree. C. and 1300.degree. C.,
preferably between about 500.degree. C. and 950.degree. C., in a
non-oxidizing atmosphere, for a period of time sufficient to ensure
that a large portion or substantially all of the starting material
has reached the desired carbonization temperature. Although the
pyrolysis may be conducted at a constant temperature, it has been
found that a slow pyrolysis, employing a gradually increasing
heating rate, e.g., from about 1.degree. C. to 20.degree. C. per
hour, preferably from about 5.degree. C. to 25.degree. C. per hour,
over many hours, produces a uniform and higher carbon yield.
[0041] After cooling, the carbonaceous material may be pulverized.
In some embodiments, the carbonaceous material is pulverized to a
fine powder. This powder may be subjected to a second pyrolysis or
polishing step, wherein the carbonized particulate material, is
again pyrolyzed in a non-oxidizing atmosphere, at a temperature
between about 650.degree. C. to about 1250.degree. C., preferably
from about 700.degree. C. to 900.degree. C. At this point, the
carbonaceous material is ready for combination with the ultrafine
particle catalyst composition along with the other components of
the fuel to produce a fuel element composition.
[0042] In embodiments of the present invention, the ultrafine
particles of the catalyst compositions can be combined with a
carbonaceous material in a number of ways to produce the fuel
element composition. One method of combination comprises intimately
mixing the carbonaceous material with the ultrafine particles.
Ultrafine particles in dry powder form (e.g. nanopowder) may be
mixed directly in a carbon mix along with other dry ingredients for
extrusion. Alternatively, the ultrafine particles may be suspended
in a liquid and the suspension mixed with extrudate.
[0043] Another method of combining the ultrafine catalyst
compositions with a carbonaceous material comprises forming the
carbonaceous material so as to concentrate the catalytic
compositions in one or more longitudinal passageways extending
partially through the fuel element. For example, the fuel element
may comprise an inner core/outer shell arrangement where the outer
shell comprises a carbonaceous material surrounding the inner core,
and the inner core comprises ultrafine particle catalyst
compositions. In some embodiments, the fuel element may include at
least one longitudinal passageway extending at least partially
therethrough.
[0044] Other methods of combining ultrafine particle catalyst
compositions with a carbonaceous material can include wash coating,
dipping, painting, spraying, or other methods known to those
ordinary skill in the art. In another embodiment, the ultrafine
particle catalyst compositions can be placed on inert support
located directly behind the fuel element in an end to end
relationship. The support for the ultrafine particles can be an
inert carbon material such as graphite or a porous material such as
alumina or porous graphite.
[0045] Once combined with the carbonaceous material, the catalyst
composition may comprise up to 10% by weight of the resulting
mixture. In some embodiments, the catalyst compositions may
comprise 1% by weight of the resulting mixture. In another
embodiment, catalyst composition may comprise 0.5% to 2% by weight
of the resulting mixture.
[0046] The density of a fuel element according to some embodiments
of the present invention can be generally greater than about 0.5
g/cc, greater than about 0.7 g/cc and greater than about 1
g/cc.
[0047] The overall length of the fuel element, prior to burning,
can be generally less than about 20 mm, often less than about 15
mm, and can be typically about 12 mm. However, shorter fuel
elements may be used if desired, depending upon the configuration
of the cigarette in which they are employed. In an embodiment, the
overall outside diameter of the fuel element can be less than about
8 mm, less than about 6 mm, and can be about 4.2 mm.
[0048] The carbonaceous and binder portions of the fuel
compositions useful herein may be any of those carbonaceous and
binder materials described in the patents recited in the Background
of the Invention, supra. Several carbonaceous and binder materials
are described in U.S. application Ser. No. 07/722,993, filed 28
Jun. 1991, now U.S. Pat. No. 5,178,167 the disclosure of which is
hereby incorporated herein by reference.
[0049] In a further aspect, the present invention provides smoking
articles. In an embodiment, a smoking article comprises a fuel
element comprising a carbonaceous material and at least one
catalyst composition, the catalyst composition comprising ultrafine
particles. With reference to a cigarette as a smoking article, the
cigarette further includes an aerosol generating means, which
includes a substrate and at least one aerosol-forming material. An
aerosol-generating means includes an aerosol forming material (e.g.
glycerin), tobacco in some form (e.g. tobacco powders, tobacco
extract or tobacco dust) and other aerosol forming materials and/or
tobacco flavoring agents such as cocoa, licorice, and sugar. The
aerosol forming material generally is carried on a substrate
material such as a reconstituted tobacco cut filler or on a
substrate such as tobacco cut filler, gathered paper, gathered
tobacco paper, or the like.
[0050] In an embodiment of the present invention, the substrate is
reconstituted tobacco, which is formed into a continuous rod or
substrate tube assembly on a conventional cigarette making machine.
Typically, the overwrap material for the rod is a barrier material
such as a paper foil laminate. The foil serves as a barrier, and is
located on the inside of the overwrap. Alternatively, the substrate
may be a gathered paper formed into a rod or plug. When the
substrate is a paper-type material, it can be positioned in a
spaced-apart relationship from the fuel element comprising a
carbonaceous material and a catalyst composition. A spaced-apart
relationship is desired to minimize contact between the fuel
element and the substrate, thereby preventing migration of the
aerosol forming materials to the fuel element, as well as limiting
the scorching or burning of the paper substrate. The spacing is
normally provided during manufacture of the cigarette in accordance
with one method of making the present invention. Appropriately
spaced substrate plugs are overwrapped with a barrier material to
form a substrate tube assembly having spaced substrate plugs
therein. The substrate tube assembly is cut between the substrate
plugs to form substrate sections. The substrate sections include a
tube with a substrate plug and void(s), which can be at each
end.
[0051] The barrier material for making the tube aids in preventing
migration of the aerosol former to other components of the
cigarette. The barrier material forming the tube is a relatively
stiff material so that when formed into a tube, it will maintain
its shape and will not collapse during manufacture and use of the
cigarette.
[0052] In embodiments of the present invention, fuel elements of a
smoking article can be advantageously circumscribed by an
insulating and/or retaining jacket material. The insulating and
retaining material is adapted such that drawn air can pass
therethrough, and is positioned and configured so as to hold the
fuel element in place. The jacket is flush with the ends of the
fuel element, however, it may extend from about 0.5 mm to about 3
mm beyond each end of the fuel element.
[0053] The components of the insulating and/or retaining material
which surrounds the fuel element can vary. Examples of suitable
materials include glass fibers and other materials as described in
U.S. Pat. No. 5,105,838; European Patent Publication No. 339,690;
and pages 48-52 of the RJR Monograph, supra. Examples of other
suitable insulating and/or retaining materials are glass fiber and
tobacco mixtures such as those described in U.S. Pat. Nos.
5,105,838, 5,065,776 and 4,756,318; and U.S. patent application
Ser. No. 07/354,605, filed 22 May 1989 now U.S. Pat. No.
5,119,837.
[0054] Other suitable insulating and/or retaining materials are
gathered paper-type materials which are spirally wrapped or
otherwise wound around the fuel element, such as those described in
U.S. patent application Ser. No. 07/567,520, filed 15 Aug. 1990,
now U.S. Pat. No. 5,105,836. The paper-type materials can be
gathered or crimped and gathered around the fuel element; gathered
into a rod using a rod making unit available as CU-10 or CU2OS from
DeCoufle s.a.r.b., together with a KDF-2 rod making apparatus from
Hauni-Werke Korber & Co., KG, or the apparatus described in
U.S. Pat. No. 4,807,809 to Pryor et al.; wound around the fuel
element about its longitudinal axis; or provided as longitudinally
extending strands of paper-type sheet using the types of apparatus
described in U.S. Pat. No. 4,889,143 to Pryor et al. and U.S. Pat.
No. 5,025,814 to Raker, the disclosures of which are incorporated
herein by reference.
[0055] If desired, the fuel element may be extruded into the
insulating jacket material as set forth in U.S. patent application
Ser. No. 07/856,239, filed 25 Mar. 1992, the disclosure of which is
incorporated herein by reference.
[0056] Examples of paper-type sheet materials are available as
P-2540-136-E carbon paper and P-2674-157 tobacco paper from
Kimberly-Clark Corp.; and the longitudinally extending strands of
such materials (e.g., strands of about {fraction (1/32)} inch
width) extend along the longitude of the fuel element. The fuel
element also can be circumscribed by tobacco cut filler (e.g.,
flue-cured tobacco cut filler treated with about 2 weight percent
potassium carbonate). The number and positioning of the strands or
the pattern of the gathered paper is sufficiently tight to
maintain, retain or otherwise hold the composite fuel element
structure within the cigarette.
[0057] In embodiments of the present invention, the fuel
element-jacket assembly is combined with a substrate section or
substrate tube assembly by a wrapper material, which has a
propensity not to burn, to form a fuel element/substrate section.
In some embodiments of the cigarettes, the wrapper typically
extends from the mouthend of the substrate section, over a portion
of the jacketed fuel element, whereby it is spaced from the
lighting end of the fuel element. The wrapper material assists in
limiting the amount of oxygen which will reach the burning portion
of the fuel element during use, thereby causing the fuel element to
extinguish after an appropriate number of puffs. In an embodiment
of the cigarette, the wrapper is a paper/foil/paper laminate. The
foil provides a path to assist in dissipating or transferring the
heat generated by the fuel element during use. The jacketed fuel
element and the substrate section are joined by the overwrap.
[0058] A tobacco section can be formed by a reconstituted tobacco
cut filler rod, made on a typical cigarette making machine, and cut
into appropriate lengths. A filter rod is formed and cut into
appropriate lengths for joining to the tobacco section to form a
mouthend section. The fuel element/substrate section and the
mouthend section are joined by aligning the reconstituted ends of
each section, and overwrapped to form a cigarette.
[0059] When a paper substrate is used, a tobacco paper rod and a
reconstituted cut filler rod are formed and cut into appropriate
lengths and joined to form a tobacco section. The tobacco section
and the fuel element assembly/substrate section are joined by
aligning the tobacco paper plug end of the tobacco section with the
substrate end of the fuel element assembly/substrate section and
joining the sections with a wrapper which extends from the rear end
of the tobacco roll to an appropriate length past the junction of
the two sections for forming the tobacco roll/fuel element
assembly. The tobacco roll/fuel element assembly is then joined to
a filter by a tipping material.
[0060] As described above, the substrate carries aerosol forming
materials and other ingredients, e.g., flavorants and the like,
which, upon exposure to heated gases passing through the aerosol
generating means during puffing, are vaporized and delivered to the
user as a smoke-like aerosol. Aerosol forming materials used herein
include glycerin, propylene glycol, water, and the like,
flavorants, and other optional ingredients. The patents referred to
in the Background of the Invention (supra) teach additional useful
aerosol forming materials that need not be repeated here.
[0061] Cast sheets of tobacco dust or powder, a binder, such as an
alginate binder, and glycerin can also be used to form useful
substrates herein. Suitable cast sheet materials for use as
substrates are described in U.S. Pat. No. 5,101,839 and U.S. patent
application Ser. No. 07/800,679, filed Nov. 27, 1991.
[0062] Suitable cast sheet materials typically contain between
about 30 to 75 weight percent of an aerosol former such as
glycerin; about 2 to 15 weight percent of a binder, such as
ammonium alginate; 0 to about 2 weight percent of a sequestering
agent such as potassium carbonate; about 15 to about 70 to 75
weight percent of organic, inorganic filler materials, or mixtures
thereof, such as tobacco dust, aqueous extracted tobacco powder,
starch powder, rice flower, ground puffed tobaccos, carbon powder,
calcium carbonate powder, and the like, and from about 0 to about
20 weight percent of flavors such as tobacco extracts, and the
like.
[0063] In one embodiment, a cast sheet material includes 60 weight
percent glycerin, 5 weight percent ammonium alginate binder, 1
weight percent potassium carbonate, 2 weight percent flavors such
as tobacco extracts and 32 weight percent aqueous extracted tobacco
powder.
[0064] The cast sheets are formed by mixing aqueous extracted
tobacco powder, water and the potassium carbonate in a high sheer
mixer to produce a smooth, flowable paste. Glycerin and ammonium
alginate are then added and the high shear mixing is continued
until a homogenized mixture is produced. The homogenized mixture is
cast on a heated belt (about 200.degree. F.) with a 0.0025 to
0.0035 inch casting clearance and is dried to yield a 0.0004 to
0.0008 inch thick sheet under high temperature air (about
200.degree. to 250.degree. F.). The sheet is doctored from the belt
and either wound onto spools for slitting into webs or chopped into
rectangular pieces about 2 inches by 1 inch which are formed into
cut filler. If the cast sheet material is used in a web or cut
filler form, normally the substrate will be from about 10 mm to 40
mm in length and extend from the rear end of the fuel element to
the tobacco segment or the front end of an extra long filter
segment (e.g., about 30 mm to 50 mm in length). In such instances
the tobacco paper plug can be omitted.
[0065] In embodiments of the present invention, the combination of
the fuel element and the substrate (also known as the front end
assembly) is attached to a mouthend piece; although a disposable
fuel element/substrate combination can be employed with a separate
mouthend piece, such as a reusable cigarette holder. The mouthend
piece provides a passageway which channels vaporized aerosol
forming materials into the mouth of the smoker; and can also
provide further flavor to the vaporized aerosol forming
materials.
[0066] Flavor segments (i.e., segments of gathered tobacco paper,
tobacco cut filler, or the like) can be incorporated in the
mouthend piece or the substrate segment, e.g., either directly
behind the substrate or spaced apart therefrom, to contribute
flavors to the aerosol. Gathered carbon paper can be incorporated,
particularly in order to introduce menthol flavor to the aerosol.
Such papers are described in European Patent Publication No.
342,538. Other flavor segments useful herein are described in U.S.
patent application Ser. No. 07/414,835, filed 29 Sep. 1989, now
U.S. Pat. No. 5,076,295 Ser. No. 07/606,287, filed 6 Nov. 1990; now
U.S. Pat. No. 5,105,834 and Ser. No. 07/621,499, filed 7 Dec. 1990,
now abandoned.
[0067] FIG. 1 illustrates a smoking article according to an
embodiment of the present invention. The smoking article depicted
in FIG. 1 comprises a fuel element 10 of the present invention
comprising a carbon source and at least one catalytic composition
comprising ultrafine particles of a metal oxide and/or metal. The
fuel element displays a plurality of passageways 11 therethrough,
about thirteen passageways altogether. The fuel element 10 is
surrounded by insulating sheet material 16 having a plurality of
grooves which facilitate the formation of the sheet material into a
jacket surrounding the fuel element. In embodiments of the smoking
article, the jacket can be made of calcium sulfate
(CaSO.sub.4).
[0068] A metallic capsule 12 overlaps a portion of the mouthend of
the fuel element 10 and encloses the physically separate aerosol
generating means which contains a substrate material 14. The
substrate material carries one or more aerosol forming materials.
The substrate may be in particulate form, in the form of a rod, and
other geometric shapes advantageous for generating an aerosol.
[0069] Capsule 12 is circumscribed by a roll of tobacco 18.
Alternatively, in other smoking articles, the capsule may be
circumscribed with an additional or continuous jacket of an
insulating sheet material. Insulating sheet materials suitable for
use in smoking articles of the present invention are further
described in U.S. Pat. No. 5,303,720 to Banerjee which is hereby
incorporated by reference. Two slit-like passageways 20 are
provided at the mouth of the capsule in the center of the crimped
tube.
[0070] At the mouth end of the tobacco roll 18, is a mouthend piece
22, comprising a cylindrical segment of a flavored carbon filled
sheet material 24 and a segment of non-woven thermoplastic fibers
26 through which the aerosol passes to the user. The smoking
article, or portions thereof, is overwrapped with one or more
layers of cigarette papers 30-36
[0071] In some embodiments, catalyst compositions comprising metal
oxide and/or metal ultrafine particles are incorporated into the
filter element of the smoking article as described in U.S. patent
application Ser. No. 10/730,962 which is hereby incorporated by
reference.
[0072] In certain embodiments of the cigarettes of the present
invention, convective heating is the predominant mode of energy
transfer from the burning fuel element comprising a carbonaceous
material and at least one catalyst composition to the
aerosol-generating means disposed longitudinally behind the fuel
element. When a foil/paper laminate is used as an overwrap to join
the fuel/substrate section some heat may be transferred to the
substrate by the foil layer. As described above, the heat
transferred to the substrate volatilizes the aerosol-forming
material(s) and any flavorant materials carried by the substrate,
and, upon cooling, these volatilized materials are condensed to
form a smoke-like aerosol which is drawn through the cigarette
during puffing, and which exits the filter piece. This smoke-like
aerosol can contain reduced amounts of carbon monoxide resulting
from the reduced carbon monoxide production of a fuel element of
the present invention upon combustion.
[0073] In some embodiments, the catalyst compositions can be
deposited on a porous support such as graphite or alumina wherein
the porous support is placed behind the fuel in an end to end
relationship.
[0074] In a further aspect, the present invention provides a method
for facilitating the reduction in the amount of carbon monoxide
produced by a smoking article, comprising incorporating at least
one catalyst composition comprising ultrafine particles of a metal
oxide and/or metal into the fuel element of a smoking article.
[0075] In another aspect, the present invention provides methods
and apparatus for the simultaneous quantification of the carbon
monoxide content and carbon dioxide content of a gaseous mixture.
In an embodiment, a method for quantifying the carbon monoxide
content and carbon dioxide content of a gaseous mixture comprises
injecting the gaseous mixture into a split injection tube of a gas
chromatograph through a single injector, resolving a relative
carbon monoxide content of the gaseous mixture on a first
chromatographic column, simultaneously resolving a relative carbon
dioxide content on a second chromatographic column, and detecting
and quantifying the eluate carbon monoxide and carbon dioxide with
a mass spectrometer. In further embodiments, the gaseous mixture
containing carbon monoxide and carbon dioxide comprises mainstream
smoke or a smoke-like aerosol produced from a smoking article.
[0076] Under some circumstances, carbon monoxide and carbon dioxide
can be resolved on a single chromatographic column. Single columns
that are capable of resolving both carbon monoxide and carbon
dioxide, however, use carrier gas at flow rates that are too high
for use with a mass spectrometer. As a result, their use precludes
the numerous advantages gained by the two-dimensional analysis of
GC/MS. Moreover, other single chromatographic columns that use a
carrier gas at acceptable flow rates for use with a mass
spectrometer cannot effectively resolve both carbon monoxide and
carbon dioxide.
[0077] The utilization of dual chromatographic columns allows for
the complete resolution of the carbon monoxide and carbon dioxide
contents of the gaseous mixture at flow rates that are acceptable
for use with a mass spectrometer. The two-dimensional analysis
provided by gas chromatography/mass spectrometry (GC/MS) can
provide precise relative quantifications of carbon monoxide and
carbon dioxide amounts present in gaseous mixtures.
[0078] FIG. 2 illustrates a flowchart for the quantification of
carbon monoxide and carbon dioxide contents of a gaseous mixture
according to an embodiment of the present invention. In particular
embodiments, the gaseous mixture comprises mainstream smoke or
smoke-like aerosol from a smoking article. The gaseous mixture is
injected into the split injector of the gas chromatogram 201. The
split injector 201 splits the gaseous mixture for simultaneous
resolution on dual chromatographic columns. The carbon monoxide
content of the mainstream smoke is resolved on a first
chromatographic column 202, and the carbon dioxide content is
simultaneously resolved on a second chromatographic column 203. The
first chromatographic column can be selected for optimal resolution
of carbon monoxide while the second chromatographic column can be
selected for the optimal resolution of carbon dioxide. For example,
a Molsieve column can be used to resolve carbon monoxide and a
wide-bore GS-CarbonPLOT column can be used to resolve carbon
dioxide.
[0079] Once resolved, the carbon monoxide content and carbon
dioxide content of the mainstream smoke are quantified by a mass
spectrometer 204. The use of a mass spectrometer adds a second
dimension of analysis that is not present with traditional gas
chromatographic detection devices. A mass spectrometer can further
resolve the carbon monoxide content and carbon dioxide content of a
gaseous mixture allowing for greater accuracy and precision when
quantifying these chemical species.
[0080] In an embodiment, an apparatus for quantifying the carbon
monoxide content and carbon dioxide content of a gaseous mixture
comprises: a gas chromatograph comprising a single split injector,
dual chromatographic columns; and a mass spectrometer.
[0081] FIG. 3 illustrates an apparatus for the simultaneous
quantification of the carbon monoxide content and carbon dioxide
content of a gaseous mixture comprising the two-dimensional
analysis of gas chromatography and mass spectrometry in an
embodiment according to the present invention. The gas
chromatograph 301 comprises a single injector 302 which splits the
sample onto two chromatographic columns 303, 304. The temperature
of the split single injector 302 can be varied in accordance with
desired analytical conditions. The temperature variance of the
single split injector 302 can be controlled manually by a user or
can be controlled electronically with any processor-equipped device
such as a computer and/or dedicated controller. As previously
discussed, one of the two columns 303 is suitable for resolving the
carbon monoxide content of a gaseous mixture while the other column
304 is suitable for resolving the gaseous mixture's carbon dioxide
content. Chromatographic columns for use in the gas chromatograph
of the present apparatus are available commercially.
[0082] The two chromatographic columns feed into a mass
spectrometer 305. Mass spectrometers suitable for use in further
resolving and quantifying the carbon monoxide content and carbon
dioxide content eluting from the two columns of the gas
chromatograph can comprise mass analyzers comprising magnetic
sector analyzers, double-focusing spectrometers, quadrupole mass
filters, ion trap analyzers, and time-of-flight (TOF)
analyzers.
[0083] The embodiments described above in addition to other
embodiments can be further understood with reference to the
following examples. Several of the fuel elements provided in the
examples below comprise percentages of BKO carbon, Guar gum,
graphite, and tobacco. Combustion of all the fuel elements in the
examples below provides energy used to generate aerosol from
tobacco and other aerosol formers like glycerin. Combustion of the
fuel elements, however, also produces carbon monoxide and carbon
dioxide. Moreover, complete combustion of the fuel elements
produces a maximum amount of energy and a carbon dioxide
by-product. Complete combustion is demonstrated by the chemical
reaction:
C (s)+O.sub.2 (g).fwdarw.CO.sub.2 (g)
[0084] Incomplete combustion, nevertheless, produces much less
energy and a substantial carbon monoxide by-product. Incomplete
combustion is demonstrated by the reaction sequence:
C (s)+O (g).fwdarw.CO (g)
C (s)+O.sub.2 (g).fwdarw.CO.sub.2 (g)
[0085] As a result, complete combustion of the fuel element in
desirable.
[0086] Graphite in the fuel elements comprising graphite, BKO
carbon, Guar gum, and tobacco, is inactive up to the temperatures
attained by combustion of the fuel element and remains
substantially unchanged throughout the combustion of the fuel
element. The remaining three carbonaceous components undergo
oxidation during the combustion to provide energy and oxides of
carbon. Among the carbonaceous components, BKO carbon is the major
component and hence chosen for the study of the fuel elements in
the examples below.
EXAMPLE 1
[0087] Several materials were prepared to evaluate the efficacy of
a method and apparatus for simultaneously resolving the carbon
monoxide content and carbon dioxide content of a gaseous mixture
according to an embodiment of the present invention. The materials
prepared for analysis by the method and apparatus were a standard
gaseous mixture (CO:CO.sub.2:N.sub.2), tobaccos from 1R4F
cigarettes, and 1R4F cigarette smoke. A small quantity of each
sample was heated to 700.degree. C. for 20 seconds in the presence
of air. The standard gaseous mixture was analyzed in the absence of
air to preserve the composition of the sample. A pyroprobe was used
for sample heating. The temperatures of the pyroprobe interface and
the gas chromatograph injector were set at ambient temperature. The
gas chromatograph utilized was a Hewlett-Packard 5890 Series II. A
single injection onto dual chromatographic columns was used for the
carbon monoxide and carbon dioxide analysis. A Molsieve column
(Chrompack, 25 M.times.0.32 mm I.D., 30 .mu.m film) was used for
carbon monoxide resolution, and a GS-CarbonPLOT column (J&W
Scientific, 60 M.times.0.32 mm I.D., 1.5 .mu.m film) was used for
carbon dioxide resolution. The temperatures of the columns were
held at 35.degree. C. for 10 minutes, programmed to 150.degree. C.
at 25.degree. C./min and held for 10 min. A single mass
spectrometer was used to identify and quantify the resolved carbon
monoxide and carbon dioxide peaks eluting from the chromatographic
columns. The mass spectrometer utilized was a Hewlett-Packard 5972
mass selective detector. The mass spectrometer was operated at 70
eV in the EI mode with the temperature of the ion source being
maintained at 180.degree. C. The mass range scanned was 20-200
atomic mass units. The carbon monoxide and carbon dioxide
quantified were only a fraction of the total carbon monoxide and
carbon dioxide generated from the heated materials. Only the
resolved carbon monoxide and carbon dioxide peak areas were used
for quantification.
[0088] The results of the standard gaseous mixture resolved on the
dual chromatographic columns are illustrated in FIG. 4. The ion
chromatogram of FIG. 4 demonstrates a completely resolved carbon
monoxide peak and a completely resolved carbon dioxide peak. For
comparative purposes, the standard gaseous mixture
(CO:CO.sub.2:N.sub.2) was injected and resolved on single column
gas chromatographs under experimental conditions consistent with
resolution on dual chromatographic columns. The standard gaseous
mixture was resolved on a single column gas chromatograph
comprising a Molsieve column. The results are illustrated in FIG.
5. As demonstrated in the ion chromatogram of FIG. 5, the Molsieve
column completely resolved the carbon monoxide content but failed
to completely resolve the carbon dioxide content of the standard
gaseous mixture. Similarly, the standard gaseous mixture was
additionally resolved on a single GS-CarbonPLOT chromatographic
column. The results of this resolution are illustrated in FIG. 6.
The ion chromatogram of FIG. 6 displays a complete resolution of
carbon dioxide and an incomplete resolution of carbon monoxide. The
carbon monoxide co-eluted with nitrogen and oxygen.
[0089] The results of the remaining sample materials comprising
tobaccos from 1R4F cigarettes and 1R4F cigarette smoke resolved on
dual chromatographic columns in accordance with the present
invention are illustrated in FIGS. 7 and 8 respectively. The ion
chromatograms of FIGS. 7 and 8 demonstrate completely and sharply
resolved carbon monoxide and carbon dioxide peaks.
EXAMPLE 2
[0090] Seven samples were generated for analysis of carbon
monoxide/carbon dioxide (CO/CO.sub.2) ratios. These samples were:
(1) Control Carbon Black 950, (2) Carbon Black 950 with 5%
Fe.sub.2O.sub.3 ultrafine particles, (3) Carbon Black 950 with 2%
Fe.sub.2O.sub.3 ultrafine particles, (4) Carbon Black 950 with 5%
TiO.sub.2--Au ultrafine particles and (5) Carbon Black 950 with 2%
TiO.sub.2--Au ultrafine particles, (6) Carbon Black 950 with 5%
CeO.sub.2 ultrafine particles, and (7) Carbon Black 950 with 2%
CeO.sub.2 ultrafine particles.
[0091] To simulate combustion of the fuel element, a pyroprobe was
used to heat a small quantity of each sample to 700.degree. C. for
20 seconds in the presence of air. 700.degree. C. is the average
temperature of a fuel element during combustion. The gaseous
mixture resulting from the combustion of each sample was analyzed
in accordance with the method delineated in FIG. 2. The pyroprobe
and gas chromatogram injector were set at ambient temperature. A
Molsieve chromatographic column was used for carbon monoxide
resolution and a GS-CarbonPLOT chromatographic column was used for
carbon dioxide resolution. A mass spectrometer was used as a second
dimension of analysis in the quantification of the carbon monoxide
and carbon dioxide contents generated by the samples. It should be
noted that the carbon monoxide and the carbon dioxide contents
quantified were only a fraction of the carbon monoxide and carbon
dioxide contents produced by the samples and that the resolved peak
areas were used for quantification. Table 1 summarizes the results
produced by the samples in this example.
1 TABLE 1 MASS ABUNDANCE (COUNTS).sup.A CO/CO.sub.2 SAMPLES CO
CO.sub.2 Ratio (1) Control Carbon 383,013,104 1,284,639,516 0.298
(2) Carbon and 5% Fe.sub.2O.sub.3 53,357,015 1,202,285,067 0.0444
(3) Carbon and 2% Fe.sub.2O.sub.3 65,069,392 1,093,984,395 0.0595
(4) Carbon and 5% TiO.sub.2-Au 131,461,228 926,581,662 0.142 (5)
Carbon and 2% TiO.sub.2-Au 264,095,113 956,314,408 0.276 (6) Carbon
and 5% CeO.sub.2 268,205,948 965,498,063 0.278 (7) Carbon and 2%
CeO.sub.2 279,547,847 977,688,888 0.286 Air Blank 655,583 7,602,213
.sup.AMass abundance is the total abundance of ions in a mass
spectrum for compound with unit of counts.
[0092] The results displayed in Table 1, which are additionally
illustrated in FIG. 9, demonstrate that ferric oxide
(Fe.sub.2O.sub.3) ultrafine particles effectuate a significant
reduction in the amount of carbon monoxide produced by the fuel
element. Fuel element sample (2) comprising 5% ferric oxide
(Fe.sub.2O.sub.3) ultrafine particles by weight exhibited an 85%
reduction in the amount of carbon monoxide produced when heated.
Similarly, fuel element sample (3) comprising 2% ferric oxide
(Fe.sub.2O.sub.3) ultrafine particles by weight displayed an 80%
reduction in the amount of carbon monoxide produced upon sample
heating. The titanium oxide-gold (TiO.sub.2--Au) ultrafine
particles of sample (4) demonstrated a carbon monoxide reduction of
52% while the ceric oxide (CeO.sub.2) ultrafine particles of sample
(6) resulted in approximately a 7% reduction.
EXAMPLE 3
[0093] Eight fuel element samples were generated for analysis of
(CO/CO.sub.2) ratios. These samples were: (1) BKO Carbon 950, (2)
BKO Carbon 950 with 5% gamma-Fe.sub.2O.sub.3-large particle, (3)
BKO 950 Carbon with 5% Fe.sub.2O.sub.3-nanoparticle, (4) BKO 950
Carbon with 2% Fe.sub.2O.sub.3-nanoparticle, (5) Carbon Mix 1
(78.3% BKO 950 Carbon, 10.1% Guar gum, 6.55% graphite, and 5.05%
tobacco), (6) Carbon Mix 1 with 5% Fe.sub.2O.sub.3-nanoparticle,
(7) Carbon Mix 2 (82.4% BKO Carbon 950, 10.6% Guar gum, and 7.0%
graphite) and (8) Carbon Mix 2 with 5%
Fe.sub.2O.sub.3-nanopaticle.
[0094] To simulate combustion of the fuel element, a pyroprobe was
used to heat a small quantity of each sample to 700.degree. C. in
the presence of air for 20 seconds. 700.degree. C. is the average
temperature of a fuel element during combustion. The gaseous
mixture resulting from the combustion of each sample was analyzed
in accordance with the method delineated in FIG. 2. The pyroprobe
and gas chromatogram injector were set at ambient temperature. A
Molsieve chromatographic column was used for carbon monoxide
resolution and a GS-CarbonPLOT chromatographic column was used for
carbon dioxide resolution. A mass spectrometer was used as a second
dimension of analysis in the quantification of the carbon monoxide
and carbon dioxide contents generated by the samples. It should be
noted that the carbon monoxide and the carbon dioxide contents
quantified were only a fraction of the carbon monoxide and carbon
dioxide contents produced by the samples and that the resolved peak
areas were used for quantification. Table 2 summarizes the results
produced by the samples in this example.
2 TABLE 2 MASS ABUNDANCE (COUNTS).sup.A SAMPLES CO CO.sub.2
CO/CO.sub.2 Ratio (1) BKO Carbon 950 136,632,880 439,836,557 0.311
(2) BKO Carbon 950 and 34,403,969 511,214,899 0.0673 5%
.gamma.-Fe.sub.2O.sub.3-large particle (3) BKO 950 and 5%
16,068,614 489,909,229 0.0328 Fe.sub.2O.sub.3-nanoparticle (4) BKO
950 and 2% 26,802,880 508,261,449 0.0527
Fe.sub.2O.sub.3-nanoparticle (5) Carbon Mix 1 98,093,373
458,829,259 0.214 (6) Carbon Mix 1 and 5% 89,003,804 491,290,439
0.181 Fe.sub.2O.sub.3-nanoparticle (7) Carbon Mix 2 105,287,470
463,439,227 0.227 (8) Carbon Mix 2 and 5% 34,534,408 478,608,718
0.0722 Fe.sub.2O.sub.3-nanoparticle .sup.AMass abundance is the
total abundance of ions in a mass spectrum for compound with unit
of counts.
[0095] The results summarized in Table 2, which are further
illustrated in FIG. 10, demonstrate that ferric oxide
(Fe.sub.2O.sub.3) ultrafine particles can effectuate a reduction in
the amount of carbon monoxide produced by a fuel element.
Comparison of the CO/CO.sub.2 ratios of sample (2) comprising 5%
gamma-Fe.sub.2O.sub.3-large particle and sample (3) comprising 5%
Fe.sub.2O.sub.3 nanoparticle reveals the dependency of catalytic
activity on particle size. The smaller Fe.sub.2O.sub.3 ultrafine
particles exhibit a greater surface area than the
.gamma.--Fe.sub.2O.sub.3-large particles which leads to higher
catalyst turnover rates and a greater reduction in the amount of
carbon monoxide produced by the fuel element upon heating. The
Fe.sub.2O.sub.3 ultrafine particles of sample (3) reduced the
carbon monoxide content of the gaseous mixture analyzed by 89.5%,
which is an 11% increase over the .gamma.--Fe.sub.2O.sub.3-large
particles.
[0096] The results of the sample testing further demonstrate the
catalytic activity of ferric oxide ultrafine particles in fuel
elements that comprise the additional components of Guar gum and
graphite. Sample (7) is an example of a fuel element containing
these additional components. Sample (8) comprises the components of
sample (7) with the addition of 5% by weight of ferric oxide
(Fe.sub.2O.sub.3) ultrafine particles. The ferric oxide
(Fe.sub.2O.sub.3) ultrafine particles reduced the carbon monoxide
production of the fuel element of sample (8) by 68% in comparison
with sample (7) which did not contain ferric oxide
(Fe.sub.2O.sub.3) ultrafine particles.
[0097] Fuel elements containing tobacco components were
additionally analyzed in this example. Sample (5) is a fuel element
containing a 5.05% tobacco content in addition to BKO Carbon 950,
Guar gum, and graphite. Sample (6) comprises the components of
sample (5) with the addition of 5% by weight of ferric oxide
(Fe.sub.2O.sub.3) nanoparticle. The ferric oxide (Fe.sub.2O.sub.3)
ultrafine particles reduced the carbon monoxide production of the
fuel element of sample (6) by 15.4% in comparison with sample (5)
which did not contain ferric oxide (Fe.sub.2O.sub.3) ultrafine
particles. The catalytic activity of the ferric oxide
(Fe.sub.2O.sub.3) ultrafine particles in sample (6) was diminished
due to the tobacco content in the fuel element composition. The
combustion of tobacco produces several chemical species that
inhibit the catalytic behavior of the ultrafine particles. This
catalytic inhibition is displayed in the 15.4% reduction of carbon
monoxide production.
EXAMPLE 4
[0098] Seven carbon samples were generated for analysis of
CO/CO.sub.2 ratios. The sample were: (1) Control Carbon (BKO 950),
(2) Carbon with 5% Fe.sub.2O.sub.3 ultrafine particles obtained
from MACH-1, Inc., (3) Carbon with 5% Al.sub.2O.sub.3 ultrafine
particles obtained from NEI, Inc., (4) Carbon with 5% CeO.sub.2
ultrafine particles obtained from NEI, Inc., (5) Carbon with 5%
TiO.sub.2 ultrafine particles obtained from NEI, Inc., (6) Carbon
with 5% tobacco and 5% Fe.sub.2O.sub.3 ultrafine particles obtained
from MACH-1, Inc., and (7) Carbon with 5% tobacco (heat treated)
and 5% Fe.sub.2O.sub.3 ultrafine particles obtained from MACH-1,
Inc.
[0099] To simulate combustion of the fuel element, a pyroprobe was
used to heat a small quantity of each sample to 700.degree. C. in
the presence of air for 20 seconds. 700.degree. C. is the average
temperature of a fuel element during combustion. The gaseous
mixture resulting from the combustion of each sample was analyzed
in accordance with the method delineated in FIG. 2. The pyroprobe
and gas chromatogram injector were set at ambient temperature. A
Molsieve chromatographic column was used for carbon monoxide
resolution and a GC-CarbonPLOT chromatographic column was used for
carbon dioxide resolution. A mass spectrometer was used as a second
dimension of analysis in the quantification of the carbon monoxide
and carbon dioxide contents generated by the samples. It should be
noted that the carbon monoxide and the carbon dioxide contents
quantified were only a fraction of the carbon monoxide and carbon
dioxide contents produced by the samples and that the resolved peak
areas were used for quantification. Table 3 summarizes the results
produced by the samples in this example.
3 TABLE 3 CO/ MASS ABUNDANCE CO.sub.2 (COUNTS).sup.B Ra-
SAMPLES.sup.A CO CO.sub.2 tio (1) Control Carbon (BKO 349,722,771
1,097,283,105 0.319 950) (2) Carbon and 5% Fe.sub.2O.sub.3
73,461,112 1,171,782,023 0.0627 ultrafine particles (3) Carbon and
5% Al.sub.2O.sub.3 323,332,586 988,477,673 0.327 ultrafine
particles (4) Carbon and 5% CeO.sub.2 285,376,477 1,032,058,820
0.277 ultrafine particles (5) Carbon and 5% TiO.sub.2 379,654,967
1,164,775,102 0.326 ultrafine particles (6) Carbon, 5% Tobacco,
184,501,337 1,042,248.352 0.177 and 5% Fe.sub.2O.sub.3 ultrafine
particles (7) Carbon, 5% Tobacco.sup.c, 199,972,837 1,165,685,787
0.172 and 5% Fe.sub.2O.sub.3 ultrafine particles Air Blank
2,501,751 12,070,258 .sup.AAll carbon samples were baked at 950 C.
prior to the analysis. .sup.BMass abundance is the total abundance
of ions in a mass spectrum for compound with unit of counts.
.sup.cTobacco was heat-treated at 100.degree. C. for 4 hours.
[0100] The results summarized in Table 3 and further illustrated in
FIG. 11 reiterate the efficacy of ferric oxide (Fe.sub.2O.sub.3)
ultrafine particles in reducing the carbon monoxide production of
fuel elements according to the present invention. When compared to
titanium oxide (TiO.sub.2), aluminum oxide (Al.sub.2O.sub.3), and
ceric oxide (CeO.sub.2) ultrafine particles, ferric oxide
(Fe.sub.2O.sub.3) ultrafine particles demonstrate a greater
reduction in the carbon monoxide production of heated fuel
elements. In this example, samples (3) and (5) containing aluminum
oxide (Al.sub.2O.sub.3) and titanium oxide (TiO.sub.2) ultrafine
particles respectively exhibited a slight increase in carbon
monoxide content. Moreover, sample (4) comprising ceric oxide
(CeO.sub.2) ultrafine particles displayed a carbon monoxide
reduction of 13%. Sample (2) comprising ferric oxide
(Fe.sub.2O.sub.3) ultrafine particles, however, exhibited a carbon
monoxide reduction of 80%.
[0101] In samples (6) and (7), ferric oxide (Fe.sub.2O.sub.3)
ultrafine particles were additionally incorporated into fuel
elements that contained tobacco as well. The reduction of carbon
monoxide produced from these fuel elements when heated was
diminished due to the catalyst poisoning chemical species generated
upon tobacco combustion.
EXAMPLE 5
[0102] Seven tobacco samples were generates for analysis of
CO/CO.sub.2 ratios. The samples were: (1) Control Camel LT.RTM.
Tobacco, (2) Camel LT.RTM. Tobacco with 5% Fe.sub.2O.sub.3
ultrafine particles, (3) Camel LT.RTM. Tobacco with 2%
Fe.sub.2O.sub.3 ultrafine particles (4) Camel LT.RTM. Tobacco with
5% TiO.sub.2--Au ultrafine particles, (5) Camel LT.RTM. Tobacco
with 2% TiO.sub.2--Au ultrafine particles, (6) Camel LT.RTM.
Tobacco with 5% CeO.sub.2 ultrafine particles, and (7) Camel
LT.RTM. Tobacco with 2% CeO.sub.2 ultrafine particles.
[0103] A Chemical Data System (CDS) Model 2000 pyroprobe was used
for sample heating. A small quantity of each sample (approximately
7 mg) was heated at 700.degree. C. in the presence of air for 20
seconds. The gaseous mixture resulting from the heating of each
sample was analyzed in accordance with the method delineated in
FIG. 2. The temperatures of the pyroprobe interface and the
injector on the gas chromatogram were set at ambient temperature.
The GC used was a Hewlett-Packard 5890 Series II gas chromatograph.
A single injection onto dual columns was used for CO and CO.sub.2
analysis. A Molsieve column (Chrompack, 25 M.times.0.32 mm I.D., 30
.mu.m film) was used for CO analysis. A GS-CarbonPLOT column
(J&W Scientific, 60 M.times.0.32 mm I.D., 1.5 .mu.m film) was
used for CO.sub.2 analysis. The temperature of the CG columns was
held at 35.degree. C. for 10 minutes, programmed to 150.degree. C.
at 25.degree. C./min and held for 10 min. A mass spectrometer (MS)
was used to identify and quantify the resolved CO and CO.sub.2
peaks eluting from the gas chromatograph. The MS used was a
Hewlett-Packard 5972 mass selective detector. The mass spectrometer
was operated at 70 eV in the El mode. The temperature of the ion
source was maintained at 180.degree. C. and the mass range scanned
was 20-200 atomic mass units. It should be noted that the CO and
CO.sub.2 quantities determined were only a fraction of the total CO
and CO.sub.2 content generates from the samples. Only the resolved
CO and CO.sub.2 peak areas were used for quantification. Table 4
summarizes the results produced by the samples in this example.
4 TABLE 4 MASS ABUNDANCE (COUNTS).sup.A CO/CO.sub.2 SAMPLES CO
CO.sub.2 Ratio (1) Camel LT Tobacco 544,728,554 1,383,849,048 0.394
(2) Camel LT .RTM. Tobacco 526,196,075 1,343,828,130 0.392 with 5%
Fe.sub.2O.sub.3 (3) Camel LT .RTM. Tobacco 532,589,297
1,354,841,196 0.393 with 2% Fe.sub.2O.sub.3 (4) Camel LT .RTM.
Tobacco 540,678,974 1,370,604,676 0.395 with 5% TiO.sub.2-Au (5)
Camel LT .RTM. Tobacco 536,124,377 1,392,004,504 0.385 with 2%
TiO.sub.2-Au (6) Camel LT .RTM. Tobacco 529,191,513 1,361,128,568
0.389 with 5% CeO.sub.2 (7) Camel LT .RTM. Tobacco 523,482,876
1,365,668,545 0.383 with 2% CeO.sub.2 Air Blank 655,583 7,602,213
.sup.AMass abundance is the total abundance of ions in a mass
spectrum for each compound with unit of counts.
[0104] The results summarized in Table 4 and further illustrated in
FIG. 12 display that the catalytic activities of the metal and
metal-oxide ultrafine particles comprising the catalyst
compositions of the present invention are inhibited when combined
with only tobacco to compose a fuel element. These results are
consistent with fuel element samples of previous examples that
contained specific amounts of tobacco. When heated or combusted,
the tobacco content of the fuel element produces several chemical
species that poison the catalytic ultrafine particles and thereby
significantly reduce, if not eliminate, the catalytic oxidation of
carbon monoxide to carbon dioxide. Consequently, tobacco components
of fuel elements according to the present invention are disfavored.
As displayed in the previous examples, however, a small component
of tobacco within the fuel element does not destroy the catalytic
activity of the metal oxide and metal ultrafine particles an
appreciable amount and is, therefore, tolerable. The inclusion of a
tobacco component in the fuel element of a smoking article can
provide more flavor to the aerosol comprising the mainstream smoke
of a smoking article.
* * * * *