Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND DEVICE FOR IGNITING CHARCOAL USING ETHYL ALCOHOL
AS A LI~ l ~:K FLUID
Background of the Invention
Charcoal, commercially available in the form of either natural wood lumps or
compressed briquets, is utilized in the grilling of food. A variety of methods have been
devised for facilit~ing the ignition of charcoal. One method involves the use of a high
temperature external heating device, e.g., an electrical heating probe, which is placed
into the charcoal. Another method utilizes a cont~inment device in the form of aventilated metal chimney, holding a mass of charcoal, creating a draft and serving to
concentrate heat within the charcoal. Such a chimney can be utilized in conjunction
with any one of a variety of flame or heat sources to ignite charcoal, e.g., burning
paper, fl~mm~ble lighter fluid, an electrical heater probe, and the like. Alternatively, a
solid fl~mm~ble accelerant such as a wax, can be placed underneath a pile of charcoal
to ignite the charcoal. The most common method in current use, involves impregnating
a mass of charcoal with a fl~mm~ble petroleum liquid, also called lighter fluid e.g.,
odorless mineral spirits, just prior to igniting the charcoal. In some instances, charcoal
may be purchased which has been already impregnated with a fl~mm~ble solid
accelerant such as a fl~mm~ble paraffin-based petroleum hydrocarbon wax or a
functionally similar material.
Each of the above methods or devices has limitations and drawbacks. The
electrical heater method requires a source of electricity, i.e., a power cord, and tends to
be slow in ignitinp~ moderate to large quantities of charcoal. Likewise, ignition of
charcoal using a solid accelerant can be slow, and the burning accelerant produces
pollution and can adversely affect the taste of the grilled food. The metal chimney
device can be effective for i~nitin~ charcoal but is cumbersome and can be dangerous
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because it requires h~n-llin~ of the hot metal device when transferring the ignited
charcoal to the grill. The method of using a petroleum-based lighter fluid for
impregnating charcoal suffers from multiple problems. First, a si~nifir~nt level of
undesirable smoke and volatile products are produced as the petroleum lighter burns,
and there are en\~ilolllllental problems associated with this release of volatile organic
compounds (VOCs). Second, the location of the lighter fluid, when applied to charcoal,
is inherently problematic. Applicant has observed that the porous charcoal acts like a
wick for the lighter fluid, and rather than igniting the charcoal, most of the fuel's heat
rises upward off the charcoal. Consequently, by the time a recommen~ie~l quantity of
fl~mm~ble petroleum lighter fluid has finished burning, often only small portions of the
charcoal have been ignited. Considerable additional time is required for combustion to
spread over the remainder of the charcoal surface. As a related problem, many pieces
of charcoal originally contacted by the lighter fluid either fail to ignite, or ignite only
briefly. Later, when food is placed on the grill for cooking, residual lighter fluid in
non-ignited pieces of charcoal tend to volatilize, i,~l~alLing an unpleasant fuel-like taste
to the grilled food. Many of the same disadvantages exist in the use of charcoal which
has been pre-impregnated with fl~mm~ble solid combustion accelerant materials. In
addition, these forms of chemically modified charcoal tend to be more expensive than
unmodified charcoal. The above disadvantages are overcome by the present invention.
Lynes, U.S. Pat. No. 1,401,803 discloses a ~lre kindler device which includes
charcoal packaged within a fl~mm~ble receptacle c~nt~ining fl~rnm~ble filling material
such as chemically treated excelsior, and an ignition fuse. Quist, U.S. Pat. No.1,461,496 describes a fire kindler for coal or other solid fuel. The device employs
asbestos sheets as wicks to absorb oil which, when ignited can ignite the solid fuel.
Quinnell, U.S. Pat. No. 2,482,797 discloses a pressureless gasoline stove cont~ining a
fuel reservoir ~llled with a porous wicking material (e.g., asbestos or sand) to regulate
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the consumption of gasoline. Graham, U.S. Pat. No. 3,739,732 describes a portable
charcoal igniter which is constructed in the form of a ventil~t~l cylindrical container with
an upper charcoal-holding portion and a lower combustion chamber portion. This lower
portion contains, in ascending order, a fuel-absorbing pad for lighter fluid or kerosene, a
metal screen, an ignition wick, and a grate to exclude the charcoal. McKenney et al.,
U.S. Pat. No. 3,779,693 describe an igniter apparatus placed under charcoal or wood,
and which is then removed. It includes an open grill-like metal container holding
ceramic chips which can be soaked with combustible fuel such as lighter fluid. Ewanika
et al., U.S. Pat. No. 3,913,557 disclose a cooking unit incorporating a heating canister
(fueled with alcohol for example) as the heat source instead of charcoal. The heating
canister heats a metal plate which propagates the heat to the food. Bandy, U.S. Pat. No.
3,933,144 describes an igniter with a wick assembly which is movable, i.e., rotatable,
~ and which is useful for i~niting charcoal. The igniter is fueled with commonly available
fuels such as lighter fluid (mirieral spirits). White, U.S. Pat. No. 4,000,732 discloses a
solid porous fire-resistant wick lighter for logs. A receptacle and the wick hold and
absorb cheap fuel such as kerosene. De la Rosa, U.S. Pat. No.4,604,053 describes a
food warming cartridge having a liquid fuel container, and a wick placed inside a lid with
an aperture. The fuel is preferably diethylene glycol. Rafford et al., U.S. Pat. No.
4,793,321 disclose a self-priming alcohol stove which includes a cup for storing alcohol
and a variety of wicks and features to control the vol~tili~tion and combustion rate of
the alcohol. Snow, U.S. Pat. No. 5,226,405 describes an ignition platform and fuel
component for kintlling a fire. The platform is hollow with multiple air inlet and air
outlet holes to intensify the combustion of solid accelerants such as waxes, placed under
wood or charcoal.
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Sulllmaly of the Invention
The invention features the use of a substantially petroleum-free and non-polluting
fl~mm~hle liquid as a charcoal combustion lighter fluid. The lighter fluid is placed in an
open vessel or carrier (preferably together with a wicking material) and positioned directly
beneath a quantity of charcoal in a conventional barbecue grill. The non-polluting
flamm~hle liquid is preferably denatured 95% by volume ethyl alcohol. Methyl alcohol,
the one carbon atom-cont~inin~ alcohol, is an alternative choice and also burns vigorously
and cleanly in air, but compared to ethyl alcohol, is even more volatile and is toxic as a
vapor. Propyl alcohol and the higher alcohols with three or more carbon atoms per
- molecule are less useful because they burn in air with a sooty flame. By contrast, ethylene
glycol, a two carbon atom-cont~ining ch~mic~l which is related to ethyl alcohol [cont~ining
an additional hydroxyl group (-OH)], burns cleanly in air but due to its very low vapor
pressure and high boiling point (198~ C), burns too slowly to be useful in the present
invention. Interestingly, ethyl alcohol (either in pure form or as a 95 % solution in the
binary azeotrope distillate with water) fails when used as a conventional lighter fluid and
applied directly to charcoal.
Considering art relating to the combustion of alcohol (either in pure form or
diluted with water), denatured ethyl alcohol has been used only as a warming fuel,
e.g., for alcohol stoves and for heating grill plates and food dishes [sold in gelled form
under the Sterno- trademark (Colgate-Palmolive Company, Tenafly, NJ)] . However,petroleum-derived fuels such as oil, kerosene, mineral spirits and mineral waxes have
been functional as ignition agents for charcoal, coal and wood, because these fully
reduced fuels (having the general formula CnH2n+2) are less volatile and burn with a
greater heat of combustion and higher flame temperature than alcohol. The alcohols
are, in fact, partially oxidized fuels having the general formula CnH2n~l0H).
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Therefore, the success of alcohol as a charcoal ignition fluid as described in the present
invention is surprising.
According to the present invention, ethyl alcohol is placed in a non-fl~mm~ble
open vessel or carrier just before use. The alcohol is preferably immobilized within a
porous wicking material placed in such an open vessel or carrier. Alternatively, a
measured quantity of alcohol can be pre-packaged and sealed in a disposable vessel or
carrier such as a heat-resistant foil pouch, preferably within a wicking material in such a
vessel or carrier, ready for use topen the pouch and ignite the alcohol~. The wicking
material and/or an optional thickening agent in the alcohol (such as
hydro~y~lo~ylcellulose), can prevent liquid spillage during use. The wicking material
also helps regulate the combustion rate of the fuel. If the alcohol is essentially
immobilized against free-flow and spillage by use of a thickening agent, or an absorbent
wicking material, then the configuration of the vessel can be as simple as a sheet of
all-rnimlm foil or other non-fl~mm~ble carrier material. For the purposes of this
invention, such a simplified vessel is termed a "carrier," and dispensing alcohol into such
a carrier can be as simple as placing thickened alcohol or an alcohol-saturated wick onto a
sheet of ~hlmimlm foil which serves as such a carrier.
(~lean-burning alcohol is provided in an adequate amount, e.g., four ounces, which
when ignited, typically burns for 15-25 minutes, thereby igniting the charcoal. In this
configuration and arrangement, the alcohol is used as an "indirect" lighter fluid because it
burns below the charcoal rather than impregnating the charcoal. The wicking material is
preferably non-fl~mm~ble, such as common glass wool m:~mlf~rhlred for home insulation
(Owens-Corning Fiberglass Corp.) or metal wool such as a meclillm tQ fine grade of steel
wool. The vessel or carrier is also preferably non-fl~mm~kle, such as a round orrectangular open shallow steel or ~lllminnm can, tray, or metal foil sheet (e.g., 4-8 inches
in diameter and between 1/4 inch and one inch deep). In setting up the barbecue grill for
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using the ethyl alcohol lighter fluid, air vents in the boKom chamber and top cover of the
grill (see Figure) should be unobstructed and kept open throughout the charcoal ignition
process. With vents open, alcohol ignited, and a controlled upward convection of heat,
the grill is preferably kept covered to exclude wind and concentrate the heat in the
charcoal.
The present invention remedies several basic problems associated with
combustion of solid and liquid petroleum-derived charcoal lighter products, especially
petroleum-derived fluids applied directly to charcoal. These problems include the
intimi~1~ting flare-up of petroleum fuel which volatili~es and ignites on the charcoal, the
surprisingly small proportion of the charcoal's surface which is actually ignited in this
process, the safety hazard associated with a petroleum-based fire, the lack of
predictability of the time required to achieve a fully ignited bed of charcoal ready for
~ grilling food, the smoke and odor of the initial fire, the associated problems in meeting
governmental clean air standards, and the residual odor and flavor of all
petroleum-derived ignition materials imparted to grilled food.
In typical modern charcoal grills, charcoal is generally supported on a
removable lower support grill, a short distance (e.g., about 34 inches) above the
bottom of the combustion chamber. Accordingly, there is adequate headroom for
placing a shallow vessel with fl~mm~ble liquid beneath the charcoal which rests on the
lower support grill (see Figure). When a porous wicking material (described above) is
placed in a one inch tall vessel, the wick's upper surface (and therefore the lighter
fluid) is located approximately 2-3 inches below the charcoal. This location is practical
and convenient for igniting charcoal in most ~;ullellLly m~nllf~ctured charcoal grills
such as the keKle style grills (WEBER~ Steven Products Company, Palatine, IL).
Including approximately 2 ounces of lighter alcohol for every 10 in2 of wick area in the
open vessel, for every 1.5-2 pounds of charcoal to be ignite~, col~LiLuL~s an
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applopLiate amount of fuel for igniting charcoal.
An important aspect of the present invention is that alcohol, a clean-burning fuel,
can be used to ignite charcoal~ The successful substitution of denatured ethyl alcohol for
conventional petroleum-type lighter fluid (e.g., odorless mineral spirits) is irnportant
because alcohol burns more cleanly, is water-extinguishable and safer, is a "generally
recognized as safe" (GRAS) material and is a biodegradable nutrient in nature, and
imparts no taste to food when it burns. Use of alcohol to ignite charcoal has not been
previously disclosed and was unanticipated for several reasons. First, ethanol and other
alcohols such as methanol have a high degree of volatility compared to the conventional
petroleum lighter fluid products. Thus, while commercial lighter fluid (rnineral spirits,
also known as naphtha and ligroin) boils at a temperature ranging from 130-145~C, 95%
by volume ethyl alcohol (plus 5% water) boils at a temperature of 78~C. Consistent with
- this high volatility, Applicant has observed that when ethyl alcohol is applied directly
onto charcoal and ignited (as is petroleum lighter fluid), it burns off very quickly (in
approximately 3 minutes) and is ineffective at igniting the charcoal (see Example 6
below). However using the indirect method of burning alcohol below the charcoal, the
alcohol can be made to burn more slowly (using, for example, a wick or wick and
grill-cont~ining device, see Figure). As most of the heat of combustion rises into the
charcoal, it ignites the charcoal placed above the alcohol.
It is worth noting that even with petroleum-based lighter fluid (odorless mineral
spirits), a shift in the location of the fuel from inside the charcoal (by liquid application), to
below the charcoal, offers some benefits over the prior art method. For example, charcoal
ignition occurs more rapidly, and is more uniform and complete, when the heat source is
placed under the charcoal. Furthermore, less disagreeable odor em~n~tes from the charcoal
to affect the taste of grilled food because the charcoal has not been impregnated with liquid
mineral spirits.
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With regard to the cost factor in converting from use of conventional "odorless"petroleum lighter fluid to the use of denatured 95% by volume ethyl alcohol, thecurrent commodity price for tank car qll~n~iti~.s of odorless mineral spirits isapproximately $1.50 per gallon, and for 95% ethyl alcohol, approximately $2.00.
While this conversion may be accompanied by a modest cost increase, there are somany advantages to the use of ethyl alcohol that the cost difference is not an important
factor. Moreover, Applicant has discovered that the improved fuel efficiency andimproved charcoal ignition obtained by combustion of a fuel beneath rather than within
the charcoal, allows at least 1/3 less fuel to be used, thereby providing a c-)mr~.n.~ting
cost savings.
Thus, in a first aspect, the invention features an improved method for i~nitin~
multiple pieces of charcoal placed in the lower portion of a grilling device, such as a
~ barbecue grill, used for cooking food. The method includes the steps of providing a
~lrst quantity of fl~mm~ble liquid or gel comprising this fl~mm~ble liquid which is
substantially free of petroleum, non-polluting upon combustion in air, and comprises at
least one alcohol. The first quantity of fl~mm~ble liquid or gel is sufficient for igniting
a second quantity of charcoal, and is dispensed into the above-described grilling device.
The fl~mm~ble liquid or gel is positioned beneath, and the second quantity of charcoal
directly above one another in the grilling device. The fl~mm~ble liquid or gel is
ignited to cause subsequent ignition of the charcoal. The steps may be performed in
any desired order in this aspect and other aspects.
In another aspect, the invention features an improved method for igniting multiple
pieces of charcoal placed in a grilling device, such as a barbecue grill, used for cooking
food. The method includes the steps of providing a first quantity of fl~mm~hle liquid or a
gel comprising this fl:~mm~hle liquid which is substantially free of petroleum and
non-polluting upon combustion in air, and a vessel or carrier which is configured and
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arranged to hold and subsequently release by vol~tili~tion and combustion, the first quantity
of ~mm~kle liquid or gel which is sufficient for igniting a second quantity of charcoal. The
first quantity of fl~mm~ble liquid or gel is dispensed into the above-described vessel or
carrier. This vessel or carrier holding the flamm~le liquid or gel is positioned beneath, and
the second quantity of charcoal directly above one another in the grilling device. The
flamm~ble liquid or gel is ignited to cause subsequent ignition of the charcoal. The steps
may be performed in any desired order in this aspect and other aspects.
In a related aspect, an improved method for ignitin~ multiple pieces of charcoalplaced in a grilling device used for cooking food is provided. The method includes
providing a first quantity of fl~mm~ble liquid or liquid-cont~ining gel which is substantially
free of petroleum and non-polluting upon combustion in air, and a vessel or carrier which is
configured and arranged to hold and subsequently release by vol~tili7~tion and combustion,
the first quantity of flammable liquid or gel which is sufficient for igniting a second quantity
of charcoal. The above-described vessel or carrier is placed at or near the bottom of the
grilling device. The first quantity of fl~mm~ble liquid or gel is dispensed in this vessel or
carrier. The second quantity of charcoal is positioned in the grilling device directly over the
fueled vessel or carrier. The first quantity of fl~mm~ble liquid or gel is ignited to cause
subsequent ignition of the charcoal.
The order of steps in the above methods can be changed for convenience and
practicality, as long as the charcoal pieces as a group, are eventually positioned a short
distance above (e.g., 0.5-5 inches above), and directly over the burning fuel.
In preferred embodiments, the above methods utilize a fl~mm~ble liquid or liquid-
cont~ining gel which is substantially free of petroleum and non-polluting upon burning in
air, with the fl~mm~hle liquid being selected from the group consisting of ethyl alcohol,
denatured ethyl alcohol, methyl alcohol, and combinations and dilutions thereof. It is
highly preferred that the fl~mm~hle liquid which is substantially non-polluting upon burning
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in air is denatured ethyl alcohol.
In another preferred embodiment, the above methods utilize a vessel or carrier which
includes a bed of porous wicking material with a non-fl~mm~ble composition. The wicking
material is provided in a configuration and amount suitable for absorbing and subsequently
releasing the first quantity of fl~mm~ble liquid or gel (described above) during combustion.
The bed of non-fl~mm~ble wicking material preferably includes either glass wool (thermal
insulation) or another inexpensive porous material such as steel wool.
In yet another embodiment of this invention, the above methods utilize a fl~mm~ble
liquid which includes at least one thickening agent selected from the group consisting of
organic and inorganic thickening agents, to reduce the flow rate and prevent spillage of the
fl~mm~ble liquid placed in the vessel or carrier. Preferred organic thickening agents include
the non-ionic cellulose polymer ether-derivatives which are soluble in organic solvents, e.g.,
~ hydroxypropylcellulose. One preferred inorganic thickening agent includes microscopic
silica particles such as fumed silica.
Another aspect features a method for immobilizing a substantially petroleum-free and
non-polluting fl~mm~ble liquid for use as a charcoal lighter fluid. The fl~mm~ble liquid is
positioned beneath multiple pieces (lumps or briquets) of charcoal placed in a grilling device
used for cooking food. The method for immobilizing the fl~mm~kle liquid is selected from
the group consisting of: holding the liquid in a non-fl~mm~le open vessel or carrier,
absorbing the liquid into a bed of porous wicking material, adding a thickening agent to the
liquid to reduce its flow rate (i.e., increase its viscosity), and combinations thereof.
In yet another aspect of this invention, a kit is provided for igniting charcoal used for
grilling food. The kit includes a container of fl~mm~hle liquid or gel. The liquid or gel is
substantially petroleum-free and non-polluting upon combustion in air. The kit also includes a
vessel or carrier which is non-fl~mm~kle and configured and arranged to hold and to
subse~uently release by vol~tili7~tion and combustion, a first quantity of the fl~mm~kle liquid
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or gel. This quantity of fl~Tnm~ble liquid or gel is sufficient for i~nitin~ a second quantity of
charcoal placed above this fl~mm~ble liquid.
In another aspect, a kit is provided for i~nitin~ charcoal used for grilling food. The kit
includes a container of fl~mm~ble liquid or liquid-cont~inin~ gel. The liquid or gel is
substantially petroleum-free and non-polluting upon combustion in air. The kit also includes a
non-fl~mm~le vessel or carrier which contains a porous wicking material. The wicking
material is configured and arranged to absorb and to subsequently reléase by vol~ti~ tion and
combustion, a first quantity of the fl~mm~hle liquid or gel which is sufficient for igniting a
second quantity of charcoal placed above this fl~mm~hle liquid.
In preferred embodiments, in the above kit, the porous wicking material is
- non-fl~lnm~ble and includes glass wool similar to.that used for thermal insulation, or another
porous material such as steel wool.
- In other p,~fel,~d embodiments, the fl~mm~ble liquid or gel in the above kits is
substantially petroleum-free and non-polluting during combustion in air, and is selected
from the group consisting of ethyl alcohol, denatured ethyl alcohol, methyl alcohol, and
combinations and dilutions thereof.
In yet other preferred embodiments of the above kits, the surfàce area of the vessel
or carrier is at least 5 in2, the depth of the vessel is at least 1/4 inch, and the first quantity
of the above-described fl~mm~ble liquid or gel is at least 1.0 ounce. In a more ~ler~;lled
embodiment of the above kits, the surface area of the vessel or carrier is between
approximately 10 and 40 in~, the depth of the vessel is between approximately 1/4 and 1.0
inch, and the first quantity of the above-described fl~mm~ble liquid is between
approximately 1 and 6 ounces. Typically the first quantity is approximately 4 ounces.
In another preferred embodiment, the above kits further include a container of
charcoal comprising at least 2 pounds of said charcoal.
In still another aspect of this invention, a kit is featured for igniting charcoal used
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for grilling food. The kit includes a container of charcoal and a non-fl~mm~ble vessel or
carrier which is configured and arranged to hold and to subsequently release by
vol~tili7~tion and combustion, a first quantity of fl~mm~ble liquid or liquid-cont~ining gel
which is substantially petroleum-free and non-polluting during combustion in air. The first
quantity of fl~mm~ble liquid or gel is sufficient for i~niting a second quantity of charcoal
placed above the fl~mm~ble liquid.
In another aspect, a kit is provided for igniting charcoal used for grilling food. The
kit includes a container of charcoal and a non-fl~mm~ble vessel or carrier which contains a
porous wicking material. The vessel or carrier and the wicking material are configured
and arranged to hold, absorb and to subsequently release by vol~ tion and combustion,
a first quantity of fl~mm~le liquid or liquid-cont~ining gel which is substantially
petroleum-free and non-polluting during combustion in air. The first quantity offl~mrn~ble liquid or gel is sufficient for igniting a second quantity of charcoal placed above
the fl~mm~hle liquid.
In preferred embodiments of the above kits, the charcoal is selected from the group
consisting of lump-type charcoal and charcoal briquets.
In another pler~ d embodiment of the above kit, the porous wicking material is
non-fl~mm~le and includes glass wool and/or steel wool.
For the purpose of convenience and speed, the above methods and kits can be
modified to elimin~te the step of measuring and dispensing fl~mm~ble lighter fluid at the
time of use. Accordingly, a factory pre-measured quantity of the fl~mm~ble lighter fluid
or gel can be sealed in a vessel or carrier material ready for use. The consumer simply
opens the vessel, places it under the charcoal, and ignites the fluid. For example, a
pre-measured quantity of 95 % by volume ethyl alcohol can be placed in a single-use sealed
vessel or carrier which is configured and arranged to hold and, upon opening and ignition,
to subsequently release by vol~tili7~fion and combustion, the ethyl alcohol whose quantity
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is sufficient for i~nitin~ a second quantity of charcoal positioned directly above the burning
alcohol.
In a ~L~r~ d embodiment the sealed vessel or carrier either includes, or is
cipally formed from a pouch with at least one metal foil layer. Such pouches, e.g.,
all"l~i"lll~ foil l~min~t~ pouches, are typically heat-resistant, prevent ethyl alcohol
evaporation and are easily opened by a tear-away tab or strip of the foil at the time of use.
In another preferred embodiment, the sealed vessel or carrier, e.g., a foil-type pouch,.
includes a bed of porous wicking material having a non-~mm~le composition (such as
glass wool or steel wool). The wicking material is provided in a configuration and amount
suitable for absorbing, and subsequently releasing the required amount of fl~mm~ble liquid
or gel during combustion.
In another preferred embodiment, the fl~mm~ble liquid includes at least one
thickening agent selected from the group consisting of inorganic and organic thickening
agents (such as hydroxypropylcellulose) to reduce the flow rate and prevent spillage of the
liquid after the sealed vessel or carrier holding the liquid is opened. In one of many possible
configurations,4-6 ounces of 95 % by volume ethyl alcohol which has been thickened to a
jelly-like consistency with addition of approximately 1% (w/v) hydroxypropylcellulose
(KLUCl~L~I) is placed in a steel wool wick pad [measuring approximately 6x5x0.5
inches(LxWxH)]. The wick pad is sealed in an ~luminllnn foil-type pouch si~ed to fit the
saturated pad. One of the two principal surfaces of the pouch is fabricated with a tear-open
tab strip which, when removed, exposes a substantial portion of one surface of the wick for
lightin~.
A kit is also provided which has been modified to make use of the above-described
ready to use, pre-measured alcohol lighter system. The kit includes a container of charcoal
and at least one single-use, sealed vessel or carrier cont~ining a premeasured first quantity
of fl~mm~ble liquid, i.e., alcohol or liquid-cont~inin~ gel, which is substantially
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petroleum-free and non-polluting upon combustion in air, wherein the sealed vessel or
carrier is configured and arranged to hold and, upon opening and ignition, to subsequently
release by vol~tili7~tion and combustion, that fl~mm~hle liquid or gel which is sufficient
for ignitin~ a second quantity of charcoal. The fl~mm~ble liquid or gel and the sealed
vessel or carrier are con~ti~lted and assembled according to the hereinabove-described
methods and options therein.
In a second aspect, the invention features a kit for igniting charcoal used for
grilling food, the kit comprising a container cont~ining at least a first quantity of
fl~mm~ble liquid or gel in the amount of at least one ounce by volume which
fl~mm~ble liquid or gel is substantially petroleum-free and non-polluting upon
combustion in air, and comprises at least one alcohol, wherein the first quantity of
fl~mm~ble liquid or gel is sufficient for igniting a second quantity of charcoal placed
- above the first quantity of fl~mm~ble liquid or gel. The kit also includes a container of
charcoal in the amount of at least two pounds.
Other features and advantages of the inventlon will be apparent from the
following description of the preferred embodiments, and from the claims.
Description of the Preferred Embodiments
The drawing will first be briefly described.
Drawing
The Figure is a side sectional view of a kettle-type charcoal-burning barbecue grill
showing a quantity of charcoal and vessel for holding fl~mm~ble charcoal lighter fluid as
described in this invention.
Use of Dellal~ ed Alcohol
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In the practice of the present invention, a premeasured quantity of denatured
alcohol is poured or otherwise delivered to a wicking material and the wicking material
is contained within a non-fl~mm~ble open vessel or carrier. The fueled
wick-cont~ining device is placed at the bottom of a charcoal grill such as a ke~tle grill
(e.g., a kettle grill m~mlf~ctllred by the Weber~ Steven Product Company). The metal
lower support grill carrying the charcoal is positioned over the fueled wick device.
The mass of charcoal is preferably arranged in a central mound approxirnately two to
four layers thick so that when flarnes rise into the charcoal, the charcoal can "hold in"
the rising heat, yet adequate heat convection through the bed of charcoal can occur.
The fueled wick device can be easily ignited by a lighted match after putting the
charcoal in place. Alternatively, the fuel can be ignited just before lowering the
charcoal support grill and charcoal into place. In the former case, a lighted match can
~ be simply dropped onto the fueled wick or, if ~r~r~lLed, an extra-long match can be
used to contact the fueled wick surface. The alcohol begins burning steadily without
any sudden flare-up.
During ignition of the charcoal, it is useful to open all of the air convection holes at the
bottom of the grill's lower combustion chamber and in the upper chamber lid (or grill cover).
Thus, the grill cover is preferably kept in place over the charcoal during the burning of the
alcohol, so as to m~int~in a uniform and upward convection of heat. The limitation and
control of air flow helps concentrate the heat in the charcoal and achieves the most rapid
ignition of the charcoal.
Applicant has experimented with the use of different fl~mm~ble fluids in developing
the present invention. Many fl~mm~ble organic liquids can initiate combustion of charcoal
when ignited in a wick pad-cont~ining vessel or carrier placed beneath the charcoal as
described above. For example, odorless mineral spirits presently marketed as a charcoal
lighter fluid by several companies including the Gulf Oil Company and Kingsford Products is
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a petroleum hydrocarbon which becomes more effective in igniting charcoal (requiring less
fluid and acting more rapidly) when placed beneath, rather than onto the charcoal. However,
the use of ethyl alcohol, i.e., ethanol, is ~l~rellcd because unlike the mineral spirits, it burns
without producing smoke or odor. Applicant has also tested methyl alcohol, i.e., methanol,
the one carbon atom-cont~inin~ alcohol, and found it to be also very clean-burning.
Although methanol can be used in the present invention, it is toxic (to breathe or drink) and is
more volatile than ethyl alcohol, causing it to burn from an open wick for a shorter period of
time than ethanol (approxim~tely 30% shorter combustion tirne for a given amount of
alcohol). The higher alcohols cont~ining three or more carbon atoms per molecule such as
isopropanol, butanol, arld the like have also been tested. All of the higher alcohols were
found to burn in air with a sooty flame and are therefore unsuitable choices for use in the
present invention. Besides burning cleanly without producing smoke or soot, ethyl alcohol is
non-toxic. To prevent l-n~nthorized use in beverages and to avoid the urmecessary expense of
paying an alcohol tax, it is plefell~d that the ethyl alcohol used in the present invention be
denatured according to standard procedures described in the prior art literature, and by the
Bureau of Alcohol, Tobacco, and Firearms.
Use of Kettle-tvpe ~rill
Referring to the Figure, charcoal-burning barbecue grill 10 is of the kettle type
(e.g., as m~ml~ctllred by Weber~ Steven Product Company, Palatine, IL), and includes a
lower charnber portion 12 supported on tripod legs 14. Two of the legs are generally
supported by wheels 16 which allow convenient transport of the grill 10 by lifting and
pulling forward on lower chamber handle 18. A catch tray 20 for burned ash debris is
positioned between, and supported by legs 14. Upper chamber lid 22 is removable by lift
handle 24, and is positioned over lower combustion chamber portion 12. Upper chamber
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lid 22 is preferably close-fitting at juncture 23 where it meets (and preferably overlaps) the
lip of lower combustion chamber portion 12, so that when lower air vents 26 and upper air
vent 28 are closed, combustion in grill 10 can be termin~te~l by shllttin~ off the supply of
air. Food support grill 30 and charcoal support grill 32 (supporting charcoal briquets 34)
are generally horizontal and parallel surfaces consisting of a welded flat array of parallel
metal support rods spaced approximately 1/2 inch apart. (~harcoal support grill 32 is
positioned approximately 4 inches above the bottom of the lower combustion chamber, and
food support grill 30 is positioned approximately S-6 inches above the charcoal support grill
32, in a typical barbecue grill. These two support grills 30 and 32 allow free passage of
upwardly moving convected air, entering initially as cool air from outside of the barbecue
grill 10 through lower air vents 26 (see arrows for air flow at 26), being heated during
passage through burning charcoal 34, and exiting through upper air vent 28 (see arrows for
air flow at 28). According to the present invention, a non-fl~mm~ble vessel 38 (e.g., a
flat-bottomed steel can, 5-6 inches in diameter, 1 inch tall) is provided for holding a
substantially petroleum-free and non-polluting fl~mm~hle liquid such as denatured ethyl
alcohol. The flamm~ble liquid is localized in vessel 38, preferably within a porous
wicking material 36. Wicking material 36 is preferably non-fl~mm~ble such as glass wool
home insulation (also known as glass felt) material or steel wool. Optionally, an
inexpensive wire mesh or expanded metal grill 40 can be placed on, or slightly above the
wicking material 36 to hold, confine, or compress the wicking material. Expanded metal
grill 40 which can be used to mask a portion of the wick area when placed directly upon the
wick, can be optionally used to reduce the fuel vol~tili7~tinn and combustion rate, and
prolong the lifetime of the ignition fire. Viewed from above, vessel 38 can be fabricated in
almost any size and shape (round or rectangular, for example) to match the size and shape
requirements, if any, of the grill. Vessel 38 can also be m~mlfactllred in the form of a
herrnetically sealed container such as a metal foil pouch holding a pre-measured quantity of
~mm~le liquid which is ready to use. The liquid is preferably combined with a wick pad
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(i.e., a bed of wicking material such as steel wool or glass wool) in the sealed container. A
thickening agent such as 1% (w/v) hydroxypropylcellulose, dissolved in the fl~mm~ble
liquid, preferably alcohol, can be helpful in immobilizing the alcohol in the container or in
the wicking material.
In the practice of the present invention, vessel 38 is placed beneath charcoal support
grill 32 and charcoal 34. A space of approximately 2 inches separates the top of vessel 38
(where the lighter fuel volatilizes and burns at the top of the porous wicking material 36)
from the underside of charcoal support grill 32. The charcoal 34 is provided in the form
of either compressed briquets or loose wood chunks, and may be piled approximately two
to four layers high over vessel 38 so that when the fl~mm~ble liquid in vessel 38 is ignited,
the flame and convected heat from the burning fuel will rise upward through the stack of
charcoal. Approximately 1-1.5 ounces of denatured alcohol is placed in vessel 38 for each
pound of charcoal. For the most effective charcoal ignition procedure, the barbecue grill
is closed and upper chamber lid 22 is put in place as shown in the Figure as soon as the
fuel is ignited. Lower air vents 26 and upper air vent 28 remain open to allow a controlled
upward flow of air during combustion of the fl~mm~ble liquid in vessel 38. Upperchamber lid 22 serves to exclude wind and, in cooperation with lower combustion chamber
portion 12, functions in the present invention to concentrate heat in the charcoal 34 (heat
generated by the burning alcohol). Therefore the presence of upper chamber lid 22 speeds
the ignition of the charcoal 34 through the adequate but not excessive flow of air through
the lower and upper air vents 26 and 28. Within approximately twenty mimltes following
ignition of the alcohol in vessel 38, the charcoal 34 is fully ignited and substantially
covered with white ash. The hot charcoal is distributed over charcoal support grill 32 and
food support grill 30 is positioned over the hot charcoal in preparation for grilling of food.
In preferred configurations of the present invention, vessel 38 shown in the Figure
is a non-fl~mm~ble open round metal cylinder such as a sheet metal steel cylinder having a
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flat bottom and a diameter of approximately four to eight inches. The height of the vessel
is approximately 1/2 to 1 inch. The vessel 38 can also be fabricated with a different shape,
e.g., square-shaped or dish-shaped with a rounded bottom. The vessel is ~Illed with a
glass wool or steel wool wicking material which is used to absorb and temporarily
immobilize denatured ethyl alcohol or any other substantially petroleum-free andnon-polluting fl~mm~ble lighter fluid just prior to, and during combustion of the fluid.
Approximately one ounce of glass wool (m~mlf~ lred by Owens-Corning Fiberglass
Corporation) when m~nll~lly compressed, fills a 5 inch diameter x 1 inch tall cylinder.
Approximately 4 ounces of alcohol is placed in the glass wool within this size of
cylindrical vessel, and conveniently ignites 3-4 pounds of charcoal briquets (ob~ained from
Kingsford Products, Oakland, CA and Royal Oak Enterprises, Inc., Atlanta, GA). For
igniting substantially greater qll~ntiti~s of charcoal, the size and surface area of the vessel
~ or alternative carrier (e.g., al~ lll foil) and wicking material may be proportionately
increased along with the amount of lighter fluid.
,
EXAMPLE 1
As a first example, 1.5 ounces of conventional petroleum-based charcoal lighter
fluid (odorless mineral spirits, Kingsford Products, Oakland, CA) was absorbed into a one
inch deep by four inch diameter glass wool bedding material (approximately 0.5 ounces of
glass wool) placed in a 3.7 inch diameter steel can. This 1.5 ounce quantity of fuel carried
in the wick-like material, burned in a smooth and controlled manner albeit with a smoky
flame and si~ni~lc~nt odor for approximately 20 minutes before the fuel was consumed.
The fire successfully ignited two pounds of charcoal briquets (Kingsford Products,
Oakland, CA or Royal Oak Enterprises, Atlanta, GA) placed 2-2.5 inches above the fuel in
a Weber~ kettle style grill (described above and shown in the Figure). Scaling up to a
similar but somewhat larger sized wick, 3 ounces of petroleum lighter fluid were similarly
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used in a 5 inch diameter glass wool bed to ignite three pounds of charcoal briquets with
similar results . The cost of producing the glass wool and steel canister used to hold the
fuel and control its burn rate are minim~l (about five cents). Moreover, this canister
device can be recovered from the barbecue grill after it has cooled, dusted free of charcoal
ash, and reused.
EXAMPLE 2
For purposes of comparison wlth conventional petroleum-type lighter fluid, an
equal amount of 190 proof (95 %) denatured ethyl alcohol was placed in the
wick-cont~ining vessels described above and used in the same Weber~ grill as described
in Example 1. The ethyl alcohol burned for a somewhat shorter period of time before
being exhausted. No visible smoke or odor was detected from the burning alcohol. For
example, 1.5 ounces of denatured ethanol burned for 15 mimltes in a 10 in2 by 1 inch
thick glass wool wick, while 1.5 ounces of conventional petroleum lighter fluid burned
for a longer time (20 minutes). In another example illustrating the use of denatured
alcohol, 4.0 ounces of denatured ethyl alcohol burned for 20 minutes after having been
placed into a 20 in2by 1 inch thick glass wool wick pad held in an open vessel (1.0 ounce
of glass~ wool had been m~n-l~lly compressed into a S inch diameter x 1 inch tall,
flat-bottom open steel can). In this latter example, 2.0 pounds of briquets weresubstantially ignited within 10 minutes after igniting the alcohol, and were completely
ignited (fully covered with a fine ash coating) and ready for use in grilling food within 20
minutes at the same time that the alcohol ceased burning. If a somewhat extendedduration for alcohol burning is desired, the amount of alcohol added to the wick can be
proportionately increased.
EXAMPL,E 3
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The utility of adding a thickener to immobilize alcohol in an open metal vessel
was tested. Accordingly, the combustion properties of 95 % ethyl alcohol samples, both
with and without a ~ickener [1.0% weight/volume hydro~y~lopylcellulose (KLUCEL~
type H)~ were compared. Small scale accelerated tests were carried out lltili7ing 2.0
millilitPr samples of each alcohol which were ignited in 3.3 centimeter diameter open
mimlm cups. Both samples burned for 122 seconds. The presence of the KLUCEL~
material in one sample caused the outer perimeter of the jelly-like ethyl alcohol material
to contract inward. Some visible bubbling and popping sounds were also observed with
KLUCEL material being present. The conclusion from this experiment is that a
thickener can be utilized to immobilize ethyl alcohol without si~nific~ntly affecting the
rate of combustion.
As a safety issue, adding a thickener to immobilize a fuel allows the fuel to
stick to surfaces including human clothing and skin. Care must be used to avoid any
burn fnJury. By contrast, ordinary denatured e~nyl aico'nol is volalile, and if acciden-al
spillage and ignition occurs, the flame is easily smothered. Importantly, water easily
extinguishes an ethyl alcohol fire since water is miscible with, and dilutes alcohol.
This ability to easily control combustion of ethyl alcohol, contrasts with mineral sp*its
and related petroleum lighter fluid products whose combustion cannot be controlled by
water because these fl~mm~ble accelerants are insoluble in water.
EXAMPLE 4
Combustion of denatured 95 % ethyl alcohol, both with and without an
alcohol-immobilizing porous glass wool wicking material (glass fiber insulation,Owens-Corning Fiberglass Corporation) to immobilize denatured 95 % ethyl alcohol was
compared. The same combustion cups described in Example 3 were used, except that one
cup was filled with glass wool before adding alcohol. Four milliliters of alcohol were
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placed in each cup and ignited. In three identical trials, combustion of the ethanol in the
wicking material was completed in 3 min 30 sec while combustion of ~e free alcohol was
completed in an average of 3 rnin 45 sec. The slightly shorter combustion time observed
using the wicking material was caused by its more rapid and immediate generation of a
full-sized flame across the entire metal cup. By contrast, 15-20 seconds were required for
warming and sufficient vol~tiliz~tion of alcohol to occur above the plain alcohol sample to
generate a full flame across the metal cup. The conclusion from this experiment is that a
porous wicking material provides several benefits (as compared with no wick). First, the
wick im~nobilizes the alcohol and transports it evenly upward for smooth combustion.
The immobilization plev~-lt~ an accidental spill of liquid in the grill, particularly as the
liquid is burning. Second, there is a speed factor, and full flame production is immt?rli~t~
using the wicking material, while it is delayed if a wicking material is not used. Finally,
the flame is fuller and more uniform using the wicking material.
- EXAMPLE 5
A comparison was made between the use of two different wicking materials for
producing good flame quality and flame duration in igniting charcoal. The same small
combustion cups described in Examples 3 and 4 were used, except one cup was filled
with glass wool while the second cup was filled with steel wool (grade 0, obtained
from the American Steel Wool Manufacturing Company, Inc., Chicago, IL). Four
millilit~.rs of alcohol were placed in each cup and ignited. In three identical trials,
combustion of the ethanol in the glass wool-cont~inin~ cup was completed in an
average of 3 min 25 sec while combustion in the steel wool-cont~inin~ cup was
completed in an average of 4 min 12 sec. The 20-25 % longer combustion time
observed using the steel wool wicking material was attributable to a slower capillary
feed rate of ethanol to the flame by steel fibers compared to glass fibers. This slower
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burn rate and longer burn time was accompanied by a flame with more blue color and
less yellow (more complete combustion). Furthelmore, the flame above the steel wool
was somewhat steadier (less flame pulsation) and generated a greater heat flux
(consistent with better combustion) than the flame above the glass wool. This greater
heat flux was evidenced by the flame's ability to boil an identical tray of water faster
and more vigorously than the flame above the glass wool.
The above benefits of using a steel wool wick (grade 0, fine steel wool) were
tested again using a full size WeberTM kettle style barbecue grill (see Figure) with three
pounds of charcoal briquets (placed in a central mound, 3-4 briquets thick) and a 5 inch
diameter wick (3/4-1 inch thick) with 4.0 ounces of denatured 95% by volume ethyl
alcohol (see Example 2 for sinular experiment with glass wool). While a comparable
amount of ethanol placed in the same sized glass-wool wick burned for 20 minutes, the
steel wool wick provided 25 mimltes of combustion time (a 25 % increase?. This
increase was consistent with the imm~ tely above observations using small
combustion cups, and is again attributed to a slower feed rate of alcohol to the flame.
EXAMPLE 6
The ability of denatured 9S % ethyl alcohol to initiate combustion of charcoal when
introduced directly onto the charcoal (using the prior art method of liquid impregnation) was
tested. Six charcoal briquets weighing approximately 1.0 ounce each (Kingsford Products
charcoal) were each treated with 3.0 milliliters of the alcohol. The alcohol was dispensed
onto the briquets by pipette. This dosage rate of approximately 10% by weight (fuel
weight/charcoal weight? was used to approximate the commercially recommended dosage
rate (instructions on the commercial package of Kingsford Products charcoal) of l.S ounces
of conventional lighter fluid (odorless mineral spirits) per pound of charcoal. This dosage
rate also approximates the amount of alcohol used in the vessel and wicking material of the
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present invention [approximately 4 ounces of denatured 95 % ethyl alcohol in a 5 inch
diameter wick to ignite 3 pounds (48 ounces) of charcoal]. As soon as the applied alcohol
finished soaking into the charcoal briquets, they were piled together and ignited. The
alcohol burned vigorously on all briquets for only 3.5 mimltes, and then the fire ceased.
When the briquets were examined, two showed no evidence of combustion. The rem~ining
four briquets showed only tiny patches of combustion on individual corners of the briquets
(less than 0.5 cm2 area of glowing area per briquet). Thus when 10% by weight alcohol is
applied directly to charcoal and ignite~, it burns off very rapidly. The alcohol either fails to
ignite the charcoal, or ignites such small areas of the charcoal that it is of limited practical
use. By contrast, Applicant's experiments placing an alcohol-delivering wicking material
(glass wool or steel wool) and a cont~inment vessel of the present invention beneath the
charcoal were fully successful. A prolonged and controlled combustion of alcohol occurred
- (typically over 15 minutes), leading to complete ignition of lump charcoal or charcoal
briquets.
EXAMPLE 7
The utility of diluting denatured 95 % ethyl alcohol with water to reduce the
combustion rate and extend the time for burning a quantity of alcohol in an open vessel (with
and without a wicking material) was tested. Tests showed that 95 % ethyl alcohol could be
diluted to approximately 75-80 % by volume, and still be easily ignited in an open tray
without a wick. Thus the burn rate of alcohol could be controlled with water (as an
alternative to using a wicking material) and, by adding a thickener such as KLUCEL~ type H
(approximately 1.0-1.5% by weight) to such an 80% by volume aqueous alcohol solution,
such solutions could be rendered substantially non-mobile. Such thickened alcohols could be
used to ignite charcoal by placing the partially gelled alcohol on an ~ mimlm foil sheet as a
carrier surface under the charcoal.
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The combustion qualitles of diluted alcohol were more significantly affected by the
presence of a wicking material. For example, dilution of the alcohol below a concentration of
85 % by volume, substantially reduced its combustion rate using a steel wool wick (fine steel
wool, grade 0). A modest and beneficial reduction in the alcohol combustion rate occurred in
the same wicking material using a 90% by volume alcohol concentration, and an improvement
in flame quality and duration were obtained. Thus, using a steel wool wick (2.5 inches in
diameter, 0.75 inch thick, with one ounce of fuel) a decrease in ethyl alcohol concentration
from 95 % to 90% caused a pronounced change in flame color from half yellow-half blue, to
all blue (suggesting somewhat slower and more complete combustion). At the same time, and
consistent with this observation, a 20% longer combustion period was obtained(l5.5 versus 13
mimltes), using 5% less alcohol.
E~AMPLE 8
The ability to initiate combustion of charcoal using a free-burning denatured
,, ethyl alcohol composition placed in a barbecue grill without using any vessel or carrier
for holding the alcohol was tested. The alcohol composition was formulated to bepoured in small proportion onto the charcoal (to act like a lighter fuse and facilitate
match-lighring), but principally down into the bottom of the grill (either onto a bed of
existing ash material or onto the metal surface at the bottom of the grill). A thickener
in the form of KLUCEL~ type H (1.2% by weight) was added to the aqueous alcohol
solution to convert it into a slow-flowing gel (similar to yoghurt consistency). As an
advantage over a simple alcohol solution, the gel could neither leak from the grill nor
be lost by undesirable absorption into porous briquets or into ash at the bottom of the
grill. As in Example 7, water was included in the denatured alcohol, reducing the
ethyl alcohol concentration to 84% by volume (82% by weight), thereby reducing the
alcohol's combustion rate and extending the burn time. The thickened alcohol gel (4.5
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ounces gel per 3 pounds of charcoal briquets) was poured from a container over astring of briquets in the first layer (to form a fuse and facilitate li~hting), with the
majority of the alcohol (approximately 90%) being poured down into the bottom center
area of the grill, a short distance below the charcoal. The remainder of briquets were
piled up in a mound over the first layer of briquets. The alcohol gel showing on the
bottom layer of briquets was lighted by match. Propagation of the flame to the alcohol
gel at the bottom of the grill followed almost immediately. Within 15-20 mimlt~s, the
burning pile of briquets were ready to be spread out into a single layer for grilling
food. This test demonstrated that the effectiveness of alcohol in initi~ting combustion
of charcoal as disclosed in the present invention does not rely upon introduction of a
separate vessel or a carrier for the alcohol.
Other features and embodiments are within the following claims.
SSSD/16525. vOl
