U.S. patent application number 09/911247 was filed with the patent office on 2002-02-21 for process and apparatus for manufacturing fuel gas and liquid fuels from trash, other waste materials and solid fuels.
Invention is credited to Stivers, ScotLund.
Application Number | 20020020112 09/911247 |
Document ID | / |
Family ID | 26915020 |
Filed Date | 2002-02-21 |
United States Patent
Application |
20020020112 |
Kind Code |
A1 |
Stivers, ScotLund |
February 21, 2002 |
Process and apparatus for manufacturing fuel gas and liquid fuels
from trash, other waste materials and solid fuels
Abstract
Improvements in the manufacture of gases and liquids from trash,
other waste, and other solid fuels, many of which also have
application in numerous other fields.
Inventors: |
Stivers, ScotLund;
(Superior, WI) |
Correspondence
Address: |
ScotLund Stivers
P.O. Box 241
Superior
WI
54880
US
|
Family ID: |
26915020 |
Appl. No.: |
09/911247 |
Filed: |
July 23, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60220609 |
Jul 25, 2000 |
|
|
|
Current U.S.
Class: |
48/198.2 ;
48/203; 48/92 |
Current CPC
Class: |
C10J 3/30 20130101; C10J
2300/0916 20130101; C10J 2300/0959 20130101; C10K 1/08 20130101;
C10J 2300/0903 20130101; C10J 3/74 20130101; C10K 1/046 20130101;
C10J 2300/1823 20130101; C10J 2300/0946 20130101; C10J 2300/1215
20130101; C10J 3/08 20130101; C10J 2300/1609 20130101; C10J
2300/0956 20130101; C10J 2300/0969 20130101; C10J 3/34 20130101;
C10J 2300/1634 20130101; C10K 3/003 20130101; C10J 3/16 20130101;
C10J 2200/158 20130101 |
Class at
Publication: |
48/198.2 ; 48/92;
48/203 |
International
Class: |
C10J 003/06 |
Claims
I claim:
1. The use of a hot bed of carbon based and/or containing material
for the purpose of decomposing oxygen containing organic compounds,
high molecular weight organic compounds, steam, nitrogen oxides,
carbon dioxide, and other undesirable compounds and/or gases.
2. The addition of alkali carbonates, silicates, oxides, and/or
hydroxides to fuels to lower the fusion point of the ash, and/or to
increase the usefulness of the ash for various uses such as
fertilizer.
3. The casting of molten slag, molten ash, molten rock, etc. into
useful shapes such patio blocks, construction blocks, frying pans,
furniture, etc. (similar to the casting of cast iron, etc.)
4. A gas producer for the gasification/liquefication of trash,
other wastes, other solid fuels, etc. where in, at or near its
bottom, only air/oxygen and/or powdered, gaseous, and/or liquid
fuels and/or their hot products are admitted so as to keep its
bottom hot enough to keep the ash, etc. in a molten state.
5. The invention of claim 4 wherein higher up in the gas producer
steam/carbon dioxide/exhaust is added, with or without additional
air/oxygen, etc. in order to convert sensible heat into chemical
energy stored in the form of hydrogen and/or carbon monoxide via
the water gas reaction and/or like.
6. A water gas generator, drawing run gases off the top, and the
blow gases approximately mid-height off the side of the water gas
generator so that all rich hydrocarbon gases, oils, and tars, etc.
formed via the cracking of oils, etc. added in the top and/or
destructively distilled from the solid fuel in the water gas
generator go primarily out with the run gases.
7. A gas producer, having excessive height so as to keep the top of
the fuel bed relatively cool (preferably not exceeding 750 degrees
Fahrenheit) so that any hydrocarbon vapors and/or gases produced
are not thermally destroyed before they can be drawn off.
8. Having a detachable and/or droppable bottom on gas producers and
water gas generators to facilitate repair, cleaning, etc. similar
to cupola practice.
9. Gas producers and water gas generators having their sides, tops,
bottoms, etc. cooled with air, gas, and/or steam before the
air/gas/steam is injected into the fuel bed within it carrying the
absorbed heat back into the fuel bed.
10. The use of turbines, steam type engines, etc. to recover energy
from hot gases coming out of gas producers, water gas sets,
furnaces, etc. before the gases are drawn in to a cooler/condenser
and/or like, taking advantage of the greater volume per mole of hot
gases and vapors before the cooler/condenser/like compared with the
cool gases and condensed liquids after going through the
cooler/condenser/like.
11. The use of gas producers and water gas sets to process trash,
waste tires, rendering plant waste, and other types of waste.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Subject matter was disclosed in provisional aplication Ser.
No. 60/220,609 United States Patent Office on Jul. 25, 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a process for recovering
gas and other useful materials from trash, other waste and solid
fuels, and, in particular, to a process for recovering oil and gas
that can be used as fuels and other materials having economic
value. The present invention also relates to an apparatus for
recovering gas, oil, and other useful materials from trash, other
waste and solid fuels. The process and apparatus of the present
invention also have application in other fields, such as oil shale,
wood, coalmine waste, tar sands, biomass, peat and coal
processing.
[0004] 2. Description of the Invention
[0005] In the 1800's and early 1900's, before gas wells and more
particularly gas pipelines became common, the standard source of
fuel gas was through the gasification of coal and coke. Coke refers
generally to the carbonaceous residue of coal after the volatile
constituents have been distilled off. The gasification of coke and
coal was generally done in water gas sets, producer gas sets, coke
by-product recovery ovens at the steel mills and also in various
types of destructive distillation units at the gas plants. The
latter units were basically large horizontal upside down
U-sectioned chambers of ceramic, or in some cases, steel. The units
were heated from underneath and were packed full of coal. The
byproducts included coke, semi-coke (low temperature coke) and tar.
The coke, semi-coke and tar that resulted were generally burned
underneath the units to heat up more coal and make more gas. The
resulting gas was essentially the sole product with commercial
viability although some of the coke, semi-coke and tar were sold at
times.
[0006] Other known means of producing fuel gas were producer gas
sets and water gas sets. A producer gas set was typically a
vertical cylinder made of steel. These cylinders were often, but
not always, lined with firebrick. Coal or coke was fed into the top
of the cylinder either manually or automatically. Air or oxygen,
with or without a mixture of steam and/or carbon dioxide, was blown
up from down below through the incandescent fuel bed. The air or
oxygen reacted with the coal or coke to first form carbon dioxide
that in turn reacted with more of the coke or coal and was reduced
to carbon monoxide. Carbon monoxide has a heat of combustion of
about 300 British Thermal Units (BTUs) per cubic foot. If steam
were also blown through the fuel bed, it would also be reduced by
the hot coke or coal to carbon monoxide and hydrogen. Hydrogen also
has a heat of combustion of about 300 BTUs per cubic foot. In the
case of a producer gas set run on air, with steam and/or carbon
dioxide and with coke as the fuel, the typical gas produced would
have a heat of combustion of about 125 BTUs per cubic foot due to
the dilution of the gas with inert nitrogen from the air. If it
were run on coal, because of the volatiles distilled off of the
coal near the top of the cylinder, the coal would produce a
considerably better gas of about 160 BTUs per cubic foot. If pure
oxygen were used instead of air, the resultant producer gas
typically had 300-500 BTUs per cubic foot.
[0007] The gas produced from a producer gas set includes possibly
some nitrogen and such combustibles as carbon monoxide, hydrogen,
some methane, and, in the case of a gas producer set run on coal, a
wide variety of volatile hydrocarbons, including vaporized tar. A
gas produced from coke typically includes, aside from the nitrogen
which would be in it from the air, approximately one third hydrogen
and two thirds carbon monoxide with a minute trace of methane. In
the case of gas made from coal, the gas contains considerably more
hydrocarbons. The gas produced was often burned straight by drawing
it into a furnace or boiler. Otherwise, the gas produced was
cleaned and cooled to remove the tar and other readily liquefiable
hydrocarbons and fly ash before burning. When the gas from the
producer gas set is burned after being cleaned (having the tar
removed), hydrogen, carbon monoxide and some hydrocarbons, such as
methane, ethane, etc. (particularly, in the case of gas made from
coal), are the gases that are primarily burned.
[0008] The process of producing a gas from the water gas set
process is similar to the producer gas set process in that the
machinery is very similar. The difference is that instead of
blowing air and steam through the cylinder simultaneously, the
water gas set process alternates between blasts of air called
"blows" and blasts of steam called "runs". The gases are drawn off
by switching valves on the top of the cylinder, so that that blow
gases (gases made with just air) go to a waste heat boiler to
generate steam, and the run gases (gases made with steam) are put
into a pipeline. In the case of a water gas set (or a producer gas
set if it's run on pure oxygen), the energy value of the gases is
around 300 BTUs per cubic foot or higher. If the gas is made from
coal or some other source of hydrocarbons that are cracked in the
top of the solid fuel column, the gas has BTU values of
approximately 500 BTUs per cubic foot or even higher.
[0009] In the 1950's natural gas entered the picture. Natural gas
pipelines were installed and natural gas was sold cheaply, which in
turn basically persuaded towns to shut down their old gasification
equipment (ex: producer gas sets and water gas sets and coal
distilleries). In years past, considerable technology was developed
for the processing of coal.
BRIEF SUMMARY OF THE INVENTION
[0010] It is a feature and advantage of the present invention to
provide a process and apparatus for recovering gas and other useful
materials from trash, waste tires, rendering plant waste, and other
waste and solid fuels such as coal, wood, coalmine waste, peat, oil
shale, biomass and tar sands. The process of the present invention
and a processor of the present invention can advantageously operate
on producer gas set cycles or water gas set cycles.
[0011] The present invention advantageously modifies and improves
technology developed for the recovery of fuel gases from coal for
use in the recovery of gas and other useful materials from trash,
waste tires, rendering plant waste, and other waste and solid fuels
such as coal, wood, coalmine waste, peat, oil shale, biomass and
tar sands.
[0012] It is another feature and advantage of the present invention
to provide a process and apparatus for recovering gas and other
useful materials from trash and other waste and solid fuels that
also allows for the recovery of oil both from the solids directly
and also via catalytically converting the gas into oil.
[0013] It is an additional feature and advantage of the present
invention to provide a process and apparatus for recovering gas and
other useful materials from trash and other waste that also allows
for the recovery of aluminum, steel, iron and other metals
typically found in trash and other waste.
[0014] To achieve the stated and other features, advantages and
objects, an embodiment of the present invention provides a process
for recovering gas and other useful materials from trash and other
waste and solid fuels such as coal, wood, peat, oil shale, biomass
and tar sands. The process of the present invention results in the
generation of fuel gas and oil, and the recovery of other useful
materials with increased yield of oil due to the height of the
solid fuel column and low temperatures on its upper end. In a
process of the present invention, a stream of trash and other waste
materials may be shredded. The stream of trash and waste materials
may comprise, for example, paper, plastic materials, glass, metals
(ex: iron, aluminum, etc.) chemical wastes, rendering plant wastes,
and tires. The trash stream is preferably passed through a magnetic
separator to remove iron and then passed through a special type of
separator, known in the art, for removing aluminum and other
non-ferrous metals. These recovered metals may be sold to a scrap
yard.
[0015] The trash stream and/or other solid fuels are then
mechanically fed to the top of an apparatus of the present
invention, a processor. An auger screw, ram or similar feed
mechanism is preferably located at the top of the processor to
constantly feed in the trash and/or solid fuel. In another
embodiment, the trash and/or solid fuel are fed down into the
processor via gravity through a vertical or diagonal shaft that is
long enough to be self- sealing.
[0016] The processor melts any metals, fuel additives, ash, glass,
etc., as it travels down through the processor into a liquid form,
which comes out of the processor. A slag tap is located at the
bottom of the processor, which allows the hot slag or molten ash
(the molten remains of trash, coal, wood, peat, etc., fed into the
processor) to be withdrawn from the processor. The materials in the
processor may be initially ignited by burning gas or oil at the
bottom of the processor at/or near the slag tap. Once materials in
the processor are initially ignited, the process is able to operate
continuously since new materials entering the processor contact
materials that have already been ignited and are also heated by the
rising hot gases as the solids fall through the column. Air and/or
oxygen is preferably blown into the bottom of the processor through
or near the slag tap right over (past) the fluid slag that is
pouring out of the processor. There may also be other air or oxygen
injection points. By adding some oil, gas, or waste organic liquids
to the gas entering the processor and burning it at the same time,
the temperature of the gas entering the processor would increase,
which would ensure that the slag flows out of the processor
fluidly. The fuel gas-air/oxygen mixture would probably be of an
oxidizing nature even after complete combustion. In one embodiment
of the present invention, the hot slag leaving the processor is
continuously poured into molds.
[0017] Another gas is preferably injected through the side of the
processor approximately halfway up the processor. A mixture of
steam and/or carbon dioxide is a preferred gas for injection. The
gas injected reacts with the hot carbon from the trash, reducing
the temperature and converting the thermal energy into chemical
energy in the form of hydrogen and/or carbon monoxide. Air and/or
oxygen can also be added at the same site and/or at different
sites.
[0018] Gas is preferably drawn out of the top of the processor.
Multiple taps may also be placed at varying heights on the side of
the processor to draw off gas. The gas produced by a process of the
present invention has a different composition and different
properties at various heights within the processor. The location of
taps on the processor vary on the particular qualities of gas
desired. This is particularly useful when used with the water gas
cycle. The gas can be run through a turbine or the like to recover
energy from the steam and other condensable components of the gas
stream before they reach the cooler-scrubber to remove them
especially if a blower, eductor or the like is located after the
cooler-scrubber to draw the gas through and out of the
cooler-scrubber.
[0019] The sizes of the various pieces of processing equipment in
the present invention are dependent on a number of factors,
including the amount of trash and solid fuel materials that is
desired to be handled and/or the amount of fuel gas or oil that is
desired to be produced. A person of ordinary skill in the art could
readily design and select processing equipment of appropriate sizes
based on these factors and others. An apparatus of the present
invention used in the recovery of gas, oil, and other useful
materials from trash and other waste and solid fuels, comprises a
processor having an auger screw, a ram or similar feed mechanism or
a gravity hopper and shaft at the top, with a slag tap at the
bottom. The processor is preferably a large, cylindrical shell, set
vertically and lined with a suitable refractory. The cylindrical
shell could also be an air-, steam-, water-, or carbon
dioxide-cooled metal shell, which can also serve as a gas injection
site. It may also have a droppable or detachable bottom. The
processor also has a side input, located approximately midway up
the cylinder or lower, for the injection of additional gas into the
processor. Hot slag may be withdrawn from the processor through the
slag tap, through which air, other gases and/or liquid fuels may
also be blown into the processor. The processor also has an outlet
near its top for withdrawing the fuel gas.
[0020] It is also a feature and advantage of the present invention
to provide a process and apparatus for recovering gas and other
useful materials from trash, chemical waste, rendering plant waste,
and other waste and solid fuels that incorporates fluid withdrawal
of the ash in the form of a molten glass-like material that in turn
can be cast into molded items, such as patio blocks or fertilizer
sticks, allowing the use of trash, solid fuels, etc., having low
ash fusion points.
[0021] The present invention also provides an advantageous use of
waste plastics to recover gas, oil and other useful materials.
[0022] It is an additional feature and advantage of the present
invention to provide a process and apparatus for recovering gas,
oil, and other useful materials from trash and other waste wherein
the costs of eliminating the trash and other waste are less than
the value of the gas generated by the process.
[0023] It is another feature and advantage of the present invention
to provide a device that improves the quality of the gas drawn from
the processor by passing it through a second processor or like
having a hot bed of low volatile solid fuel to decompose any steam,
carbon dioxide, oxygenated hydrocarbons, etc., and to crack heavier
hydrocarbons in the gas. The gas drawn from the first processor can
also be burned with preferably an excess of air/oxygen immediately
before being fed into the low volatile fuel bed of the second
processor, which in turn converts the steam, carbon dioxide, and
heat (both from the combustion of the initial gas-air/oxygen mix
and from the excess oxygen reacting with the solid fuel) into
carbon monoxide and hydrogen. This second processor, which I call a
beneficator, can also be used on gases, vapors, liquids, etc., from
sources other than a processor for the purposes of hydrocarbon
cracking, destruction of oxygen containing organic compounds such
as dioxanes and organic acids, destruction of nitrogen oxides, and
reduction of steam, water vapor, and carbon dioxide.
[0024] The gas preferably enters a beneficator after leaving the
cooler-scrubber or the processor itself. The beneficator, a device
of the present invention, operates to remove materials such as
nitrogen oxides, organic acids, dioxins, and other undesirable
materials from a gas stream. The gas is blown through a hot
coke/charcoal bed and is reduced down to carbon monoxide and
ordinary hydrocarbons, etc. A beneficator of the present invention
may also use a wood charcoal bed, a bed of chars from lignite or
any other extremely low volatile carbonaceous material that can be
used as a fuel and other chemical reactant.
[0025] Additional objects, advantages and novel features of the
invention will be set forth in part in the description that
follows, and in part will become more apparent to those skilled in
the art upon examination of the following, or may be learned by
practice of the invention.
DETAILED DESCRIPTION
[0026] Referring now in detail to an embodiment of the present
invention, a process and apparatus are provided for recovering gas,
oil and other useful materials from trash and other waste. For
example, the present invention may be utilized with solid waste,
coal, lignite, peat, tires, wood, coke, biomass, oil shale, tar
sands, paper, a wide variety of chemical waste, and a wide variety
of other things. The process of the present invention results in
the recovery of fuel gas, oil and other useful materials. In the
case of tires, plastics or anything with a substantial hydrocarbon
content (as opposed to a relatively pure carbon material like
coke), the process of the present invention invariably results in a
gas having various quantities of hydrocarbons, many of which may be
distilled off the top. In that regard, when trash is used in the
process of the present invention, considerable quantities of oil
may be recovered. Likewise, oil may be recovered when coal,
biomass, lignite and various other materials containing
hydrocarbons are used as a fuel.
[0027] When the gas produced from the process of the present
invention is burned hot and the gas contains tar/oil and came from
a source like trash or bituminous coal, the gas usually contains at
least an additional 40 BTUs per cubic foot based on the presence of
the hydrocarbons that are heavy enough to condense normally at room
temperature, plus the sensible heat.
[0028] The trash used in the present invention preferably also
comprises paper, other materials with hydrocarbons content (such as
plastics, etc.), and other organic materials. By pre-moving steel
and other inorganic materials, the quantity of ash to be removed
from the processor is reduced. Further, the pre-removal of
inorganic materials also produces valuable byproducts, such as
aluminum and steel that can be recycled. For example, the aluminum
and steel could be sold to a scrap yard.
[0029] The stream of trash and other materials entering the
processor of the present invention is preferably shredded, passed
through a magnetic separator to remove the iron, and then passed
through a special type of separator for removing aluminum and other
non-ferrous metals. The removal of metals from the incoming stream
would pay for the costs of removal based on the scrap prices of the
metals removed and would substantially reduce the amount of slag
produced by the processor. Further, removing the metals would also
improve the fluidity of the slag because instead of having
appreciable quantities of iron oxide and aluminum oxide getting
into the slag, the slag would be substantially glass and paper ash,
which are more easily fusible. Additives such as glass, sodium
silicate, sodium carbonate, potassium carbonate, coal and coal
ashes, etc., can be added to make the ash even more fusible.
[0030] The stream of trash and other materials entering the
processor may further comprise glass. Although glass may be
separated from the stream prior to entering the processor, it is
preferable to leave it in the stream. Glass is more difficult to
remove from a waste stream than metals are because it is not
susceptible to electro-magnetism. Further, glass has a very limited
market value for scrap whereas metals such as iron, aluminum and
copper have considerable value for scrap and are fairly easy to get
rid of If glass goes into the processor, it is processed with the
waste papers, the plastics and other materials in the processor.
The glass will melt and flow out of the processor with the slag and
tends to reduce the fusion point of the slag.
[0031] The stream of trash and other materials entering the
processor preferably comprised plastics. Plastics are useful in the
present invention because they have a high volatile content, have
high energy, and produce little ash. So consequently, the higher
the plastics content of the stream going to the processor, the
better it is. Besides improving the quality of the gas by having a
large plastics content, it will also improve the quantity of
recoverable hydrocarbons that will be coming out in the hot gas
stream.
[0032] The hot slag or ash leaves the processor as a molten
glass-like material. In one embodiment of the present invention,
the hot slag or ash is withdrawn from the processor and cast into
molds. For example, the hot slag can be cast in to patio blocks and
sold. By using the hot slag, additional waste is eliminated and
additional revenue is generated for the operator of the processor.
An operator of a processor of the present invention earns money
through acceptance fees for taking the trash, the scrap metal value
of the aluminum and steel separated from the trash, the sale of the
oil and gas produced by the process and the sale of any molded
materials produced from the hot slag.
[0033] An apparatus of the present invention preferably comprises a
processor. The processor is preferably a large, cylindrical shell,
set vertically and lined with a suitable refractory. Suitable
refractories include, but are not limited to carbon, silicon
carbide, magnesium silicate, calcium aluminate, magnesium
aluminate, aluminum oxide, magnesium oxide, calcium oxide, and
cooled metals. Alternatively, the cylindrical shell could be an
air-cooled, steam-cooled, water-cooled or carbon dioxide-cooled
metal shell, which can also serve as a gas injection site or
boiler. Trash is mechanically added to the top of the processor
after typically first being shredded and having the metals removed
from it magnetically, or the trash is added whole. An auger screw
or similar feed mechanism preferably located at the top of the
processor to constantly feed in trash. Alternatively, the trash,
whole or shredded, is dumped down a gravity fed shaft. The shaft is
preferably long enough to be self-sealing. Persons of ordinary
skill in the art could readily determine an appropriate shaft
length that is self-sealing. A self-sealing shaft is advantageous
because it could also act as a pressure relief valve for the
processor if necessary.
[0034] The bottom of the processor is preferably heavily lined with
refractory and would have a slanting slag tap. The internal bottom
and slag tap of the process may be similar to a cupola or blast
furnace, with a fixed, a detachable and/or droppable bottom. The
slag tap would preferably have air and/or oxygen blown in through
it. A fuel gas or liquid fuel may also be added to the slag
tap.
[0035] The air and/or oxygen are preferably blown into the bottom
of the processor through the slag tap right over the fluid slag
that is pouring out of the processor. By adding some oil, gas or
waste organic liquids to the air/oxygen entering the processor and
burning it at the same time, the temperature of the gas entering
the processor would increase, which would ensure that the slag
flows out of the processor fluidly. The mixture would be of an
oxidizing nature even after complete combustion. As noted above, in
a preferred embodiment, the slag leaving the processor would
typically go directly into molds. The molds may, for example, form
the slag into patio blocks, or fertilizer sticks.
[0036] The processor bottom operates at extremely high temperatures
because it has to be hot enough to melt glass, ash and other
materials into slag. For example, the lowest part of the processor
may operate at temperatures greater than 2500 degrees Fahrenheit.
If oxygen is used as the gas entering the processor, the
temperature in the processor may be greater than 4400 degrees
Fahrenheit. Oxygen is preferable to air for use in the apparatus
and process of the present invention. Oxygen operates more
efficiently than air and increases the quality of the output fuel
gas because it is not diluted with nitrogen, whose presence reduces
the BTU valve of the gas.
[0037] Different chemical and thermal activities are taking place
at different heights within the processor during operation. Thus,
taps can be placed at various heights on the processor to draw off
gases having different compositions and different properties. The
bottom portion of the processor operates as a very hot oxidizing
combustion situation, which bums out the remaining carbonaceous
materials. The carbon is on the descending column of solid fuel
(e.g., the trash) within the processor. The processor melts the
ash, glass, etc. into a liquid form, which comes out of the
processor. Moving up from the bottom portion within the processor,
the temperature falls as carbon dioxide and water vapor produced in
the first combustion reaction react with the hot carbon it comes in
contact with forming additional carbon monoxide and hydrogen.
[0038] In a preferred embodiment of the present invention, at a
point higher up in the processor (i.e., above the bottom portion),
a gas is injected through the side of the processor. A mixture of
steam and carbon dioxide is a preferred gas for injection. Steam or
carbon dioxide alone may also be injected. A mixture of air, steam,
oxygen and/or carbon dioxide may also be injected. Exhaust from
engines, furnaces, turbines, boilers or other process equipment
located nearby may also be injected through the sides of the
processor. The injected carbon dioxide and steam mixture reacts
with the hot carbon from the trash reducing the temperature further
and converting the thermal energy into chemical energy in the form
of hydrogen and carbon monoxide. Any air or oxygen injected tends
to increase the temperature. As the gases rise through the column,
they also destructively distill the plastics, paper and other
materials within the fuel bed, reducing them to basically a
cokelike material. This reduction of plastics, paper and other
materials liberates more gases, which are basically combustible,
and also recoverable liquid hydrocarbons that distill out with the
hot gas.
[0039] Gas is preferably drawn out of the top of the processor.
However, taps may be placed at varying heights on the processor to
draw out gases having different compositions and different
properties.
[0040] Besides being able to operate on a producer gas cycle as
described above, a processor of the present invention can also be
operated on other cycles, such as water gas cycle. A water gas
cycle would typically draw off blow gases at a lower level (a lower
height in the processor) than the producer gas cycle. The run gases
would be still drawn off of the top so that all of the oil and rich
hydrocarbon gases made from the upper layers of the fuel bed via
destructive distillation would only go off with the run gases and
not the wasted by going off in the blow gases.
[0041] After leaving the processor where they are formed, the hot
fuel gas and oil/tar vapor mix can either be fed hot into suitable
burners in a furnace or boiler where it is burned, both gases and
oil vapors, or it can be drawn through a cooler and scrubber or
like, to remove and recover the oil/tar which can then be used or
sold separately.
[0042] The cooled, washed gas preferably next enters a device of
the present invention known as a beneficator, which further
improves the quality of the gas. The beneficator is preferably a
vertically set, metal cylinder. Alternatively, the beneficator may
be diagonally set. The beneficator is preferably used to remove
undesirable materials from a lower grade gas. For example, the
beneficator operates to remove materials such as sulfur oxides,
nitrogen oxides, organic acids, dioxins, carbon dioxide, steam and
other undesirable materials from a gas stream. In the present
invention, gas drawn from the processor preferably enters the
beneficator after leaving the cooler-scrubber. The gas is blown
through a red to white-hot coke bed and is reduced down to carbon
monoxide, nitrogen, hydrogen and ordinary light hydrocarbons. A
beneficator of the present invention may also use a wood charcoal
bed, a bed of chars from lignite or any other extremely low
volatile carbonaceous material that can be used as a fuel or other
chemical reactant.
[0043] The gas coming out of the beneficator will be hot, but will
be relatively clean of steam, hydrocarbons, dioxins, and oxygenated
hydrocarbons. The gas leaving the beneficator will likely contain
some nitrogen (depending on whether the processor and beneficator
were air blown or oxygen blown), plus carbon monoxide, hydrogen,
methane and the like. When the beneficator is properly run, the gas
will not contain any appreciable amounts of carbon dioxide, water
vapor, dioxins, organic acids, nitrogen oxides or other similar
contaminants. The gas leaving the beneficator is fairly clean other
than possibly a trace a mount of fly ash from the coke, which can
easily be removed prior to end use of the gas as fuel, chemical
feedstock or whatever. The process of the present invention can
operate as a batch process, but it preferably operates as a
continuous process. An auger screw, a ram, a gravity fed shaft or a
similar feed mechanism, which can be automatically controlled by
sensors, is preferably located at the top of the processor, which
would be constantly feeding in trash and/or other solid fuels. At
the bottom of the processor, the slag is coming out continually
with molds mounted on a track, a rotor or conveyor belt so that the
molds are continuously passing underneath the processor to catch
the slag. The process of the present invention preferably
incorporates sensors, which control the speed at which the molds
move in order to avoid overfilling or under filling the molds. A
continuous version of the present invention can run 365 days per
year, except occasionally the process may need to be shut down to
repair the refractory in the processor or to rebuild the diesel
engines or other machines fueled by the process. Otherwise, the
process operates continuously.
[0044] The present invention is economical to operate because it
generates value at the beginning of and throughout the process. An
operator initially makes money in the form of acceptance fees to
take the trash and, in addition to that, the value of the gas at
the far end is also significant. The fuel gas produced by the
process of the present invention can be burned to generate
electricity, such as to power a ship or a city, for example. The
present invention also allows for the recovery of liquid
hydrocarbons that can be processed into oil, motor oil, fuel oil,
diesel fuel and gasoline. The materials molded from the hot slag,
such as patio bricks, may be sold for profit. Finally, the
aluminum, steel and other metal separated from the trash stream may
also be sold for value.
[0045] The fuel gas may also be passed through a Fischer Tropsch
catalyst to make even more oil or through a methanol catalyst to
make methanol, or through a Noble metal or similar catalyst to make
ammonium oxalate and/or ammonium formate. The Fischer Tropsch
catalyst converts a mixture of hydrogen and carbon monoxide into
oil and a by-product of either water vapor or carbon dioxide
depending on which catalyst is used and its operating
conditions.
[0046] Various preferred embodiments of the invention have been
described in fulfillment of the various objects of the invention.
It should be recognized that these embodiments are merely
illustrative of the principles of the present invention. Numerous
modifications and adaptations thereof will be readily apparent to
those skilled in the art without departing from the spirit and
scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWING
[0047] The drawing shows an embodiment of a trash/other waste/other
solid fuel processor and also, as modified in the part of the
"description of the preferred embodiment" describing the
"beneficator", the beneficator.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0048] Referring to the drawing, reference numeral 10 generally
identifies my trash, other waste material, and solid fuel processor
comprising a vertical shaft 11 into which trash, other waste and/or
solid fuel are fed in to from fuel hopper 12 via auger 13. After
leaving the auger 13, the fuel piles up in slowly descending fuel
bed 14 where it is gradually heated by contact with the solid fuel,
etc., beneath it, and also by the hot, gases and vapors rising up
from down below and going through the solid fuel, drying it, and
destructively distilling it. As the gases, vapors, and steam rise,
they eventually reach gas and vaporized oil pipe 15 and exit
vertical shaft 11 through pipe 15. Meanwhile, the upper solid fuel
in fuel bed 14 continues to descend, and is heated to over 1000
degrees Fahrenheit, around which point it begins to react with the
steam being injected into vertical shaft 11 at steam ports 16,
forming hydrogen, carbon monoxide, and possibly some carbon
dioxide, absorbing sensible heat in the process. After the solid
fuel passes by steam ports 16, it begins to react with preheated
air, being injected into vertical shaft 11 via air injection ports
17 according to the reactions: O2+2C.fwdarw.2CO plus heat;
O2+C.fwdarw.CO2 plus much heat; heat+CO2+C.fwdarw.2CO. The
nitrogen, of course, remaining generally unreacted. (Any traces of
nitrogen oxides formed are immediately destroyed by reacting with
the hot carbon monoxide, carbon, etc.) The temperature in this
region of the vertical shaft, as well as farther down below are
extremely hot, generally well over 2500 degrees Fahrenheit, and
often well over 3000 degrees Fahrenheit, causing the ash, together
with any additives, such as sodium carbonate, potassium carbonate,
sodium silicate, glass, etc. to fuse into a molten ash, slag, or
man made lava which flows out of the bottom of vertical shaft 11
via diagonal discharge pipe 20 while pilot gas burner 21 (which is
kept lit by pilot light 22) is blasting a gas and/or other flame
with excess air into discharge pipe 20 blowing upwards into
discharge pipe 20 over the downwards flowing molten ash (preventing
the ash from cooling off, so as to keep it flowing smoothly) and on
into the bottom of the vertical shaft 11, adding heat, superheated
exhaust (nitrogen, carbon dioxide, steam) plus superheated air to
the solid fuel bed to react with it and produce more hydrogen,
carbon monoxide, etc., which rises upward in vertical shaft 11 and
adds to the other fuel gases being formed there. The fuel gases and
vaporized oils/tars exit vertical shaft 11 at its top through pipe
15 with most of the vaporized oil and fuel gas going out pipe 23 to
end uses as hot raw gas and/or to cooler-scrubbers or like to cool
it and recover the oil to use or sell elsewhere, with the cold,
fairly clean gas either going to an end use, or to further
purification in a beneficator (to be discussed and described
below). However some of the gas, rather than going out pipe 23, is
drawn via pipe 24 together with a large amount of outside air into
air blower 25 which blows both fuel gas and air into pilot gas
burner 21,which as mentioned before, the flame from which, among
other things, keeps the molten slag in discharge pipe 20 hot and
flowing down through spout 18 into mold 19. The bottom of vertical
shaft 11 is cooled externally by water jacket 28 (which generates
steam to supply steam ports 16) and is supplied with water from
reservoir 26, which is kept full by float valve 27. Air blower 31
supplies air to air injection ports 17 via heat recovery channels
29 and 30 (which can be constructed of concentric shells,
clusters/layers of pipe, angle iron, steel channel, etc. to cause
the heat radiating out of vertical shaft 11 to be absorbed by the
air going to air injection ports 11, cooling the sides of vertical
shaft 11, and possibly reducing or eliminating the need to line
part or all of vertical shaft 11 with refractory, as well as
recycling the heat back into fuel bed 14 improving the thermal and
chemical efficiency of the system.
[0049] A beneficator is merely a processor 10 as described above
except that instead of steam being fed in to it via steam ports 16,
gases and/or liquids containing such things as oxygenated
hydrocarbons (such as organic acids and dioxins), carbon dioxide,
steam, high molecular weight hydrocarbons, nitrogen oxides, sulphur
oxides, etc. are fed in order to decompose them into extremely low
boiling point desirable fuel gases, etc. A beneficator is normally
fed with only low volatile solid fuel such as coke or char.
* * * * *