U.S. patent application number 11/676641 was filed with the patent office on 2008-01-03 for low emission energy source.
Invention is credited to Arnold J. GOLDMAN.
Application Number | 20080000436 11/676641 |
Document ID | / |
Family ID | 32825153 |
Filed Date | 2008-01-03 |
United States Patent
Application |
20080000436 |
Kind Code |
A1 |
GOLDMAN; Arnold J. |
January 3, 2008 |
LOW EMISSION ENERGY SOURCE
Abstract
A power generator provides power with minimal CO.sub.2,
NO.sub.x, CO, CH.sub.4, and particulate emissions and substantially
greater efficiency as compared to traditional power generation
techniques. Specifically nitrogen is removed from the combustion
cycle, either being replaced by a noble gas as a working gas in a
combustion engine. The noble gas is supplemented with oxygen and
fuel, to provide a combustion environment substantially free of
nitrogen or alternatively working in 100% oxygen-fuel combustion
environments. Upon combustion, Very little to no nitrogen is
present, and thus there is little production of NO.sub.x compounds.
Additionally, the exhaust constituents are used in the production
of power through work exerted upon expansion of the exhaust
products, and the exhaust products are separated into their
constituents of noble gas, water and carbon dioxide. The carbon
dioxide may be used in conjunction with a biomass to accelerate the
biomass growth and to recover the oxygen enriched air resulting
from algae photosynthesis for enhancing the operation of the power
generator using the as Biomass for processing into methanol/ethanol
and biological oils as fuel for the power generator. The biomass
fuel is seen as a solar fuel and may be used in conjunctions with
other solar fuels like heated thermal oil and others, as well as
clean fossil fuels to optimize to clean, and efficient operation of
the power generator in various regulatory contexts.
Inventors: |
GOLDMAN; Arnold J.;
(Jerusalem, IL) |
Correspondence
Address: |
Patent Counsel;Moser, Patterson & Sheridan, LLP
Suite 1500
3040 Post Oak Blvd.
Houston
TX
77056-6582
US
|
Family ID: |
32825153 |
Appl. No.: |
11/676641 |
Filed: |
February 20, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10760915 |
Jan 20, 2004 |
7191736 |
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11676641 |
Feb 20, 2007 |
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60441088 |
Jan 21, 2003 |
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Current U.S.
Class: |
123/18R ;
60/614 |
Current CPC
Class: |
F25J 2230/80 20130101;
F25J 3/0426 20130101; F02M 25/0222 20130101; F25J 2230/08 20130101;
Y02T 10/32 20130101; F25J 3/04072 20130101; Y02E 10/46 20130101;
F25J 2205/20 20130101; F02M 25/00 20130101; F25J 3/04563 20130101;
F25J 2235/50 20130101; Y02T 10/30 20130101; F25J 2260/58 20130101;
F25J 2210/80 20130101; F02B 43/02 20130101; Y02T 10/12 20130101;
F25J 2260/80 20130101; Y02T 10/121 20130101; F02B 47/02 20130101;
F25J 3/04157 20130101; F02D 19/12 20130101; F03G 6/00 20130101;
F25J 2260/44 20130101 |
Class at
Publication: |
123/018.00R ;
060/614 |
International
Class: |
F02B 53/00 20060101
F02B053/00 |
Claims
1. A power generator, comprising: a supply of gas for the
combustion of fuel therewith, said supply having substantially only
a single species of gas therewith; a supply of fuel; a combustion
chamber operatively coupled in fluid communication with said supply
of gas and said supply of fuel and operatively coupled to an
exhaust; a turbine in fluid communication with said exhaust and in
fluid communication with a secondary exhaust therefrom, and further
having an output shaft; a steam turbine in fluid communication with
said secondary exhaust, said steam turbine further including a
second output shaft.
2. The power generator of claim 1, further including a generator
coupled to at least one of said output shaft and said second output
shaft.
3. The power generator of claim 2, further including: a fuel supply
separator; and a gas for combustion separator.
4. The power generator of claim 3, wherein: said gas for combustion
separator includes: an ambient air intake: a chiller section
capable of separating, from a stream of air brought into said
separator, at least the nitrogen therein and leave behind, for
combustion, at least the oxygen components of the air.
5. The power generator of claim 3, wherein: said fuel supply
separator includes: a fuel intake: a chiller section capable of
separating, from a stream of fuel brought into said separator, at
least the nitrogen therein.
6. The power generator of claim 1, wherein said gas for combustion
is high purity oxygen.
7. The power generator of claim 6, further including a biomass; a
exhaust gas separator; a separator for separating oxygen from the
environment of said biomass; a converter for converting the biomass
to fuel to said engine combustion chamber; wherein, said power
generator generates electricity using at least 75% of its operating
fuel as fuel converted from said biomass.
8. The power generator of claim 6, further including additional,
non-biomass based, solar generation.
9. The apparatus of claim 8, wherein said solar generation
includes: a plurality of solar heaters a tank; and a steam turbine
connected to the solar heaters and tank for the passage of
superheated water therethrough.
10. The apparatus of claim 9, wherein: said solar generation alone
provides a full rated capacity of a plant operated during the peak
need and peak solar hours; and said steam turbine may be
selectively energized by the passage of solar generation
superheated water or from the exhaust stream of a gas turbine.
11. The apparatus of claim 10, wherein the solar generation may
include: hot thermal fluid heated by solar collectors or hot
thermal fluid that had been heated by solar collectors and is
stored for this purpose; biomass fuel grown on the site of the
power generator; and biomass fuel produced at off-site location and
brought to the site.
12. A method of generating power; comprising the steps of:
providing a combustion volume; providing, to the combustion volume
a quantity of gas for combustion and a quantity of fuel; combusting
the fuel gas mixture; passing the combusted mixture to a gas
turbine, the combusted mixture passing therethrough and exerting
work to provide energy at an output shaft thereof; passing the
mixture, to a steam turbine, the mixture causing work to be
generated and energy to be available on a steam turbine output
shaft; connecting at least one of the output shaft and steam
turbine shaft to an electrical generator; passing the exhaust from
the steam turbine to a secondary steam turbine; recovering useful
work from the secondary steam turbine output shaft as the exhaust
passes therethrough; passing the exhaust, from a secondary turbine
exhaust to a gas separation system; and recovering components of
the exhaust.
13. The method of claim 12, further including the steps of:
providing an air separator; passing air through the separator and
separating at least nitrogen therefrom; and passing from the
separator, to the combustion chamber, substantially pure oxygen
forming the gas for combustion.
14. The method of claim 12, further including the steps of:
supplying a fuel separator; passing fuel, through said separator
and removing at least the nitrogen therefrom; passing the fuel on
to the combustion chamber for combustion with the oxygen.
15. The method of claim 14, wherein the separator is a heat
exchanger and the fuel is passed through one side of the heat
exchanger and coolant, below the vapor phase temperature of
nitrogen, is passed through the other side of the heat
exchanger.
16. The method of claim 15, further including the steps of:
separating, from the exhaust stream, at least carbon dioxide;
providing a biomass; providing the separated carbon dioxide to the
biomass; growing the biomass in the presence of sunlight and the
carbon dioxide to form further biomass and O.sub.2; and removing
the O.sub.2 therefrom; converting the grown biomass into a fuel;
providing the fuel and the oxygen to the combustion volume;
providing supplemental fuel, other than the biomass derived fuel,
to the combustion volume in a ratio of less than 25%.
17. The method of claim 16, wherein an additional solar generation
paradigm is used to augment the operation of the power generator,
and wherein, said power generator generates electricity using at
least 75% of its operating fuel as fuel converted from said biomass
or from other solar means.
18. The method of claim 17, wherein the additional solar paradigm
is a thermal solar paradigm.
19. The method of claim 17, wherein peak solar insulation and
off-peak electrical demands in a specific location overlap or
nearly overlap and, 25% of the fuel used for power generation is
non-biomass fossil fuel, minus a modest reserve such that the solar
generator and solar paradigm together are reproducing the maximum
output possible during these peak hours.
20. The method of claim 19, wherein the thermal solar paradigm
alone provides the full rated capacity of the plant operated during
the peak need and peak solar hours
21. A method of claim 20, where the solar thermal paradigm may
include a fluid heated by solar collectors or fluid that had been
heated by solar collectors and is stored for this purpose biomass
fuel grown on the site of the power generator biomass fuel produced
at off-site location and brought to the site.
22. The method of claim 21, further including the step of:
expanding the capacity of the power generator during on peak hours
through the use of a combined cycle gas-steam turbine generator and
wherein the full capacity of the gas turbine component of the
combined cycle power generator a biomass fuel will be used.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of co-pending U.S.
application Ser. No. 10/760,915, filed Jan. 20, 2004 which claims
benefit of U.S. provisional patent application Ser. No. 60/441,088,
filed Jan. 21, 2004 which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the present invention generally relate to
power generation, more particularly power generation incorporating
combustion, such as internal combustion engines, including power
generation wherein it is desirable to reduce the emission of oxides
of nitrogen, hydrocarbons, carbon dioxide and particulates. More
particularly still, embodiments of the invention include power
generation using a power source having a regeneration mechanism,
whereby emissions from combustion are recovered for reuse as a
source of fuel for the power source. Additionally, the power
generation methods and apparatus herein may be used to provide
solar generation capability.
[0004] 2. Description of the Related Art
[0005] Power generation employing internal combustion engines is
traditionally accomplished by introducing fuel (Typically a
hydrocarbon based fossil fuel or distilled hydrocarbon fuel) and
air into a combustion chamber or volume, and igniting or exploding
the fuel, in the presence of oxygen supplied in the air, to cause
expansion or increased pressure in the chamber, thereby causing
relative movement of a combustion chamber component. The movement
of the combustion chamber component is employed to cause a
consequent output from the engine, typically in the form of torque
and rotation of a shaft extending therefrom. For example, in a
piston type of engine the increased pressure caused by the
combustion of the fuel-air mixture causes movement of a piston in
piston housing, and the piston is connected, through an arm, to a
rotatable crankshaft. Likewise, in a gas turbine style of engine,
the fuel-air mixture is combusted in a combustion chamber, and the
expanding gaseous result passes through a plurality of rotationally
mounted finned rotors, causing them to rotate with torque. The
result is rotation of a shaft, such as a shaft upon which these the
rotors are mounted, the shaft being coupled to a generator, a
vehicle or the like, to power the generator or vehicle.
[0006] In such internal combustion engines, the efficiency of the
engine, as measured by power output on the shaft as compared to the
potential power provided by the fuel, is on the order of 30% to
60%. The difference between actual energy recovered and potential
energy available, i.e., the 70% to 40% loss in efficiency, is a
result of several factors, including inadequate or incomplete
combustion of the fuel, generation of wasted heat, frictional
losses in the mechanisms used to transform the chemical energy
released in combustion to physical energy in the output shaft,
exhausting of the combusted mixture before complete recovery of the
energy thereof, etc. Each of these factors adds to yield a
relatively inefficient internal combustion engine.
[0007] One mechanism that has been used in the past to increase the
efficiency of the fuel use has been to use the heat remaining in
the exhaust to either generate heat for building heating purposes,
or to generate further power through a steam turbine, or the like.
For example, the temperature of the exhaust of a gas turbine is
sufficient to heat and often to superheat steam, which may then be
passed through a steam turbine for energy generation therefrom.
Thus, the energy recovered in the output of the steam turbine is
added to that recovered by the gas turbine as a measure of
efficiency. However, gas turbines as a primary engine and without a
method of secondary heat recovery are less efficient than diesel
cycle engines, which is currently, on a stand alone basis (i.e., no
secondary heat recovery based power generation) the most efficient
engines commercially available. Further, engines operating on the
Stirling cycle would theoretically be more efficient, but have
never gained commercial acceptance. The relatively efficient diesel
engine using commercial fuels has an exhaust temperature
insufficient for efficient steam turbine power generation
therewith, whereas the gas turbine has high enough combustion
temperature, and exhaust temperature, to allow sufficient heat
recovery for commercial uses. The gas turbine with such a heat
recovery system is currently the most efficient commercially
available system for combustion based electricity production
[0008] Several methods have been used or proposed to increase the
efficiency of the internal combustion engine itself. One such
methodology includes modifying the air used for combustion by
enhancing the oxygen percentage thereof. As a result, a greater
percentage of oxygen is available in a given volume of air-fuel
mixture (as oxygen displaces Nitrogen in the air), resulting in the
ability to have a greater quantity of oxygen and fuel in the
mixture per unit volume, and a resulting higher combustion
temperature. As is known that if the temperature of the combustion
reaction is increased the resulting efficiency of the engine should
increase, various schemes have been proposed in the past to provide
such an increase in both temperature and efficiency. For example,
it is known to combine or mix additional oxygen with the air intake
of an internal combustion engine, with a resultant substantial
increase in energy recovery efficiency. Further, emissions of
carbon monoxide, hydrocarbons and particulates were substantially
decreased. As naturally occurring air has an oxygen content of
about 21%, the added oxygen both raises the combustion temperature
and increases the total quantity of fuel combustible in a
combustion chamber of a given size. For example, adding sufficient
oxygen to air so that the resulting mixture is 35% oxygen, and
employing a diesel cycle engine and diesel fuel, has been
demonstrated to result in significant increase in power output for
an engine, as the greater concentration of oxygen allows greater
quantity of fuel to be introduced and combusted. However, the
engine also released, as exhaust, unacceptably rich emissions of
greenhouse gasses as nitrogen oxides, approximately double that of
a non-oxygen enriched diesel cycle engine, and also was unable to
be effectively controlled. Although the amount of Nitrogen in the
oxygen enriched air is less (because, on a volume to volume
comparison, some is replaced by oxygen) and thus one would expect
fewer NO.sub.X emissions, the increased temperature caused a higher
reaction rate or reactivity between nitrogen and oxygen, resulting
in a greater efficiency and power output, a lower emission of
particulates, CO and other compounds, the production rate of
NO.sub.X compounds also was significantly increased. As a result,
this concept has not been further pursued.
[0009] An ongoing issue with the use of fossil fuels or other
hydrocarbons in conjunction with internal combustion engines is the
generation of pollutants, such as NO.sub.x or CO.sub.X compounds. A
portion of these emissions, specifically the NO.sub.X compounds,
are known to cause disruption of the ozone layer, and/or smog, as
well as being generally unhealthy when inhaled. CO is toxic, as is
an additional emission gas, CH.sub.X, Likewise, CO.sub.2 has been
implicated in global warming, and the emission of it may become
limited in the future. Thus, although the efficiency of the engine
can be increased, the resulting pollution is unacceptable.
[0010] An additional method of power generation is solar power,
such as a solar energy generating station or "SEGS," in which solar
energy is converted to electricity. As solar energy is unavailable
during the night, such SEGS plants are typically used to generate
"peak" and mid peak power, i.e., they are used during periods of
the day when the sun is shining when electricity demand is highest.
These peak times are locale dependant, such as, for example,
locations of high solar insulation where the need for electricity
to power air conditioning units is much higher in summer months.
Alternatively, or additionally, such peaks can occur as electrical
consumers return to their homes in the late afternoon or early
evening hours, and begin using air conditioners, appliances and the
like. To provide the peak power needed, utilities are often willing
to pay an a higher charge to the power generator, including SEGS,
for this power during peak hours. Further, these peak plants are
often operated only during peak demand periods, and thus their
cost, i.e., the investment in infrastructure, is not recoverable
based upon continuous generation, but rather based on less that
full utilization.
[0011] Although SEGS have proven to be capable of providing power
during peak operation times, there are limits of competitiveness
which affect their use for base line power generation needs. As the
plants cannot operate in non-daylight hours, the cost of building
the solar power generation equipment must be justified based solely
upon generation during these daylight hours. Thus, the electricity
generated must be capable of being sold at a premium over
electricity generated at power stations where the power generation
is continuous, i.e., base line plants which operate continuously,
24 hours a day, except when down for maintenance or unusual lack of
electricity demand). In localities that have significant
disparities base load and peak load, it is not uncommon for peak
load to be 2 to 6 times larger then base load requirements. In
these localities with big disparities between base load and peak
demands it is important to encourage building peaking plants that
do not run many hours this incentive is usually provided by
providing substantially higher prices or values on peak pricing.
Even with substantially higher priced peaking power it is usually
the case that economic analysis will determine that it is most
beneficial to the energy supplier to meet these requirements with
the lowest cost, typically less efficient and more environmentally
unfriendly systems than solar. In order to encourage clean energy
sources to supply this peak power, incentives are sometimes
offered. The incentives often give clean a energy supplier delivery
preferences either by accepting clean energy on a first priority
basis against other suppliers if they are priced equally, or to
allocate some percentage of peak or as delivered energy to be
supplied from clean energy sources. As well as the delivery
preference a tax environment of specific SEGS benefits are often
provided to make of an even tax playing field between SEGS
suppliers and fossil fuel plant providers. As a potential supplier
of clean energy, SEGS plants, which are based on the delivery of
solar thermal sources of energy, are in an unusual position. On one
hand they are able to deliver clean energy from solar and they are
also able to produce energy by using fossil fuels to power a steam
turbine otherwise normally powered from solar energy. Were the SEGS
to receive preferences associated with its clean solar delivery it
is usual practice to limit the amount of fossil fuel energy the
SEGS plant is entitled to produce relative to the solar energy that
it produces and requires the plant to produce 100% of its output
capacity from solar energy alone.
[0012] Solar energy plants which often deliver energy during peak
demand hours typically provide that energy as a direct consequence
of the amount and intensity of the solar incident light that falls
on the solar field, with the solar field being comprised of
photovoltaic fields or solar thermal fields. However solar thermal
fields have an added flexibility. Solar thermal plants typically
operate by raising the temperature of some intermediate fluid to
high temperature and then circulate that intermediate fluid through
a heat exchanger that boils water, and resultant steam is used to
run a steam turbine to make electricity. However it is technically
quite easy for the solar thermal steam to be provided by fossil
fuel and not just from solar source. Thus when the sun is not
shinning a the power block portion of the solar thermal plant is
able to operate by using fossil fuel to directly heat the water in
a parallel boiler, creating steam to run the turbine. This added
flexibility allows solar thermal plants to be available to supply
energy then when the sun is available and when the sun is not
available. However, because of the limitations on the use of fossil
fuels and the requirement that the plant must be able to produce
100% of its rated output from solar alone to receive preferential
supply status and certain tax and other benefits of being
considered solar, the fossil fuel based generation is minimally
used and sub-optimum power generation equipment is used. For
example, although it may be reasonable to combine gas turbine and
solar generation, the cost effective solar plants available before
this new technology are not able to produce for technical reasons
the full rated power of the plant from solar alone. Thus a current
SEGS plant cannot operate highly efficient combined gas-steam cycle
turbines and still be considered a solar plant in many if not all
locales. Most solar energy equipment at most can heat an
intermediary fluid converted to steam and drive a turbine to
temperatures of about 400.degree. C. Whereas, in order to run a
highly efficient combined gas-steam turbine, where the waste heat
exiting the gas turbine is fed into the steam turbine, the initial
temperature of the compressed air entering the gas turbine must be
heated to 2000.degree. C. The gap of 1600.degree. C. needed to
bridge this gap results in commercial solar fields, are running the
most efficient steam turbines at approximately 40% efficiency
instead of the most efficient combined cycle plant running a 60%
efficiency. There does exist one type of solar collector technology
called a power tower, which focuses a large number of mirrors, each
one independently shining the sunlight onto a small location at the
top of a very tall tower. That location at the top of the tower
becomes very hot, in excess of 2000.degree. C. The goal of this
design was to be able to obtain temperatures that would be able to
run efficient combined gas-steam turbine systems. However for many
reasons most of which can ultimately be related to lack of
sufficient material technology at this stage this approach is too
expensive, inefficient and unreliable to be developed in to a
commercial product. Further improvements at the material science
level that may take many years to develop must still made.
[0013] Therefore, their exists a need in the art for a power
source, particularly one using a combustion based engine, wherein
the resulting efficiency is increased without the production of, or
with a significant reduction in the production of, byproducts such
as NO.sub.X and CO and particulates in the resulting emission
stream, and with greater efficiency than prior art devices.
Likewise, there is a need to provide solar based generating
capacity (SEGS) having more widespread use, significant increases
in efficiency, and significant increases in valuable on-peak
delivery of energy and power compared the amount of energy and
power delivered off peak. All the above being achieved within
frameworks that are consistent with restricted fossil fuel use.
SUMMARY OF THE INVENTION
[0014] The present invention generally provides a higher
efficiency, lower emission, power generator, by virtue of operation
of an internal combustion engine in the absence of, or with a
relatively restricted amount of, air or materials in the air which
contribute to NOX formation. In one aspect, the power generator is
an engine is operated by introducing a combination of a fuel, a gas
for combustion with the fuel and a noble gas into the combustion
chamber of an engine, and combusting the fuel and gas therein. In
one aspect, the noble gas is argon. In another aspect, the gas for
combustion is oxygen.
[0015] In another aspect, the power generator is coupled to a gas
and heat recovery system, in which the exhaust resulting from
combustion is recovered and the heat is used to generate power. In
one aspect, this includes providing a separator to separate the
noble gas from the exhaust and reusing the noble gas for further
use in the power generator. In another aspect, this includes
providing a reaction mechanism for reacting the non-noble gas
components with an expansion medium to separate the individual
components of the remaining exhaust stream. In a further aspect,
this includes providing a separator to separate CO.sub.2
components, of the exhaust stream and a biomass for the recovery of
oxygen therefrom. In a still further aspect, a reinsertion system
is provided to direct the oxygen back into the power generator.
[0016] In another aspect, a method of generating power includes
providing a mixture of noble gas and combustion gas to a combustion
location, providing a quantity of fuel to the combustion location
and initiating combustion, and converting at least a portion of the
generated energy into a physically useable form. In one aspect, the
generation is provided in an internal combustion engine, and the
power is removed from the power generator by virtue of a rotating
shaft.
[0017] In another aspect, the method includes recovering the gas
stream resulting from combustion, such that the noble gas is
separated from the gas stream and reused in the power generator as
a carrier gas for further combustion. In another aspect, this
includes combining the non-noble gas constituents with a reaction
medium to convert these gasses to their constituent elements. In a
further aspect, this includes separating components of the exhaust
stream having combustible gasses therewith, and directing them to a
biomass for the recovery of combustible gasses therefrom. In a
still further aspect, a combustible gasses recovered from the
biomass are reinvested into the power generator. In a still further
aspect, the combustible gasses include oxygen. In a still further
aspect, the reaction medium is superheated steam or water.
[0018] In additional aspects, the power generator may be combined
with additional resources for exploitation thereof. For example,
the generator may be used as the engine for a vehicle, such as a
road vehicle, a railroad vehicle, a ship's power plant and the
like. Likewise, the power generator may be combined with other
power generation schemes for greater utility. In a still further
aspect, the exhaust of the power generator may, either before or
after separation, or in a partially separated composition, be used
to heat water or another liquid for use in generating a steam
turbine or for otherwise producing heat for commercial and/or
residential uses, such as heating.
[0019] In another aspect, the power generator may be combined, with
a solar generating capacity, to provide a substantially increased
generating capacity. In this aspect, a power generator includes an
internal combustion engine. A burner is supplied, upstream from the
gas turbine, in which oxygen and fuel are combined and combusted.
This high pressure high temperature stream of the products of
combustion is then passed through the turbine to generate power at
the output shaft thereof. To provide oxygen for combustion with the
fuel, air is passed through a chiller and the oxygen separated
therefrom is passed on the burner. Additionally, to reduce the
occurrence of greenhouse gasses, the natural gas is passed through
a chiller, causing the nitrogen therein to precipitate therefrom
before the introduction of the gas to the burner. The exhaust
stream, after passing through the turbine, is used in a secondary
recovery system, to further extract energy therefrom and cool, the
exhaust stream. In one aspect the exhaust stream is separated into
its individual components, and the components are further used. In
an additional aspect, this includes passing the CO.sub.2 in the
exhaust stream to a biomass, and converting the carbon dioxide and
biomass into additional biomass and oxygen for reuse in the burner.
In another aspect, the solar component of the power generator is
the growth of the biomass and the recovery of fuel and oxygen
therefrom
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a schematic view of an embodiment of the power
generator of the present invention;
[0021] FIG. 2 is a sectional view of a rotary engine component
useful in the power generator of FIG. 1;
[0022] FIG. 3 is a schematic of a control system used in
conjunction with the components of the rotary engine of FIG. 2;
[0023] FIG. 4 is a perspective view of the rotary engine of FIG. 1,
with certain components removed therefrom for clarity of
illustration;
[0024] FIG. 5 is a perspective view of the end of a rotor which is
a component of the rotary engine of FIGS. 2 and 4;
[0025] FIG. 6 is a schematic view of a portion of the heat transfer
and gas separation portion of the power generator of FIG. 1;
[0026] FIG. 7 is a schematic view of a biomass recover scheme
useful in an embodiment of the power generator of FIG. 1;
[0027] FIG. 8 is a table comparing the efficiency of the power
generator of the present invention with that of a conventional
application;
[0028] FIG. 9 is a schematic representation of an additional
implementation of the power generator of FIG. 1; and
[0029] FIG. 10 is a schematic representation of an additional power
generator system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] So that the manner in which the above recited features of
the present invention can be understood in detail, a more
particular description of the invention, briefly summarized above,
may be had by reference to embodiments, some of which are
illustrated in the appended drawings. It is to be noted, however,
that the appended drawings illustrate only typical embodiments of
this invention and are therefore not to be considered limiting of
its scope, for the invention may admit to other equally effective
embodiments.
[0031] FIG. 1 is a schematic representation of an embodiment of the
power generator of the present invention, showing the individual
components and their interconnection useful for generating power
with minimal emission and a relatively high efficiency.
Essentially, in this embodiment, the major components of the
invention include an internal combustion engine 16, such as a
diesel cycle engine, an engine heat recovery and gas separator
system 23 for the separation of the various components of the
exhaust or emissions of the engine, an input unit 100, from which
fuel and gasses useful in the combustion of the fuel are stored or
generated and then introduced to the engine, and a separator
portion 180, from which the separated exhaust or emission
components are recovered for further use. In steady state operation
of the power generator of this embodiment, the air is brought into
the input unit 100 and the oxygen is separated therefrom for
introduction into the engine through an injector, while a working
gas, in this embodiment a noble gas such as argon is combined with
fuel and introduced through the engine manifold to reach the
combustion chamber 18 of the engine 16 and combine therein with
oxygen to create a fuel oxygen mixture to be combusted. The oxygen
and fuel combust to form H.sub.2O and CO.sub.2, which along with
the noble gas, are exhausted to the engine heat recovery and
separator system 23, and thence to separator system 180, where the
three main components thereof are separated from one another. (It
will be understood by those skilled in the art that a small portion
of CO will likely be produced, but these trace amounts are
minimal). The CO.sub.2 recovered from the exhaust stream is
directed into an oxygen recovery portion 190, in this embodiment a
biomass composed as an algae bed, where photosynthesis converts the
CO.sub.2 and water into additional plant material and oxygen, or
the CO.sub.2 is stored for reuse or sale. The oxygen is recovered
for reinsertion into the engine 16. Likewise, the H.sub.2O may be
separated cryogenically, such that the oxygen therein may be
reinvested into the engine, and the hydrogen recovered for other
uses, including as a fuel for the engine. Additionally, in this
embodiment, the power generator includes the ability to operate in
a non-recycling mode, where supplies of oxygen are not readily
available or genera table onboard. Thus, there is provided a power
generation system in which power may be generated from carbon based
fuels using traditional engine technologies, with minimal or zero
emissions of NO.sub.X and CO compounds.
[0032] Referring still to FIG. 1, these features are provided by
providing an engine 16, in this embodiment an engine operable on
the diesel cycle, i.e., in which the combustion of the fuel-oxygen
mixture is compression triggered. To provide the fuel-oxygen
mixture, input unit 100, in this embodiment, includes cryogenic
separation unit 1, which is selectively communicable with both the
ambient condition, typically atmospheric air, as well as a supply
of air dischargeable from air chiller 6, through an air selection
valve 5. Air, upon entering the cryogenic separation unit 1, is
reduced in temperature to at or below the temperature at which the
constituents therein separate by phase, and thus many constituents
of the air may be separated therefrom. In particular, the cryogenic
separation unit 1 is configured to separate oxygen from the air for
storage in a liquid oxygen tank 102, argon for storage in an argon
storage tank 7, and nitrogen for storage in a nitrogen storage tank
104. In this embodiment, the nitrogen in nitrogen storage tank is
ported, via nitrogen line 106, to the air chiller 6, to pre-cool
the air entering the cryogenic separation unit 1. The nitrogen may
also be collected for sale or other uses. Thus input unit 100
provides, from ambient air, both argon for use as a working gas for
the power generator as well as oxygen for use in combustion of the
fuel to be introduced.
[0033] Referring still to FIG. 1, input unit 100 further provides
the fuel and mixes such fuel for introduction to the engine 16.
Specifically, in this embodiment, a carbon based fuel such as
methane is mixed with argon for injection through the injector 110
of the engine 16, where it is combined and combusted with oxygen
likewise introduced therein. In this embodiment, the fuel is stored
in fuel tank 4, and is ported, through fuel line 108, to turbo
mixer 10 (which may take the form of a turbocharger) where it
combines with argon supplied to the turbo mixer through argon line
112 extending from argon storage tank 7. Once mixed in the turbo
mixer 16, the argon-fuel mixture is introduced to the intake
manifold 17 of the engine 16. The mixture then travels though the
intake manifold 17 to a combustion chamber 18 of the engine, it
being appreciated that the engine 16 includes multiple such
combustion chambers, each bounded by a chamber wall and a piston,
the piston attached to a crank shaft such that upon combustion the
piston moves outwardly of the combustion chamber and transmits
power to the crankshaft and after exhausting the combustion
products, fresh fuel, working gas and oxygen is introduced and the
crankshaft pushes the piston inwardly of the combustion chamber to
compress the mixture therein to the combustion pressure. The
crankshaft may form, or is coupled to, the engine out put shaft
(not shown).
[0034] As the fuel-argon mixture is ported into the intake manifold
17 of the engine 16, the oxygen is ported to the combustion chamber
18. This is accomplished, in this embodiment, by providing a
cryogenic pump 9 and imposing a modest pressure to push the oxygen
along a thermally insulated oxygen line 11 to a pressure
amplification fuel injection system 12, such as a HEIU system
available from Caterpillar industries or a MEFIS system available
from Mazrek. The injectors of this system preferably include nozzle
heads with hardened components or surfaces, to increase wear
resistance in the hostile combustion chamber 18 environment. By
using this configuration, the oxygen may be cryogenically pumped to
the engine 16 with minimal parasitic losses, yet may be pressurized
to enable injection into the combustion chamber 18 when it reaches
the combustion chamber 18. To regulate the temperature and pressure
in the oxygen line 11, the line 11 is ported to a intermediate high
pressure overflow chamber 13, as well as a temperature control unit
14 which may heat or cool the line 11, as needed, to maintain the
proper temperature (approximately -170C) and pressure in the line
11. Dampeners 120 are provided in the line 11 immediately before
the terminus thereof at the amplification fuel injection system 12
to minimize resonance on the line 11. Such a dampener can be a
pressure regulator, such as a spring loaded piston or a membrane
which enables change in the volume of the line immediately before
the amplification fuel injector system 12, or simply an additional
pipe dead headed from line 11 immediately before the amplification
fuel injector system 12.
[0035] The amplification fuel injection system 12 provides pressure
amplification of the oxygen, and injection thereof in a liquid
state, to the combustion chamber. The actual amplification level is
set to optimize the combustion cycle and the overall efficiency of
the power generation system. Where the engine 16 is a diesel cycle
engine, the amplification is on the order of 10 to 20 to one or
greater, thereby injecting at a pressure on the order of 200 to 250
MPa and minimizing the Cryogenic pump 9 pressure requirements and
is in the range of current cryogenic pump capability. For example,
pumps such as the PD series of cryogenic pumps, available from
Chart Industries, Inc., would operate acceptably. Where a spark
based combustion engine is employed as engine 16, the pressure
amplification and cryogenic pump pressures may be lower, as the
pressure in the combustion chamber 18 into which the oxygen must be
injected is lower. Referring still to FIG. 1, after the oxygen and
fuel-argon mixture are received in the combustion chamber 18,
compressed by the piston and ignited, the combustion products are
exhausted therefrom conventionally through an exhaust manifold 122
and ultimately to the separator system 180, which is, in this
embodiment, configured in three stages: A first stage to reduce the
heat of the exhaust gasses and capture that heat in a different
media for further use, a second stage to further cool the exhaust
stream and recover useful work or power therefrom and reduce the
temperature thereof to the point where separation of the component
is possible, and a third stage wherein the exhaust stream
components are separated out. Thus, in the first stage of the
separator system 180, these combustion products, which exit the
engine 16 at a temperature on the order of 800C are then ported
through an exhaust line 124 to pass through one side of the heat
exchanger of the heat injector/injection water pump 20 which
provides the first stage of transferring a significant percentage
of the heat to the cooling water in which is a superior form from
which to convert engine heat into a form from which it is more
easily possible to recover from the heat useful down stream work
and thereafter cooling of the gases through volumetric expansion.
These exhaust gasses exchange heat and thereby superheat highly
pressurized water flowing through the other side of the heat
exchanger. In this embodiment, the water entering the heat
injector/injection water pump 20 is that which has just exited from
the engine's cooling system 16. In the heat exchange process the
engine's exhaust gases heat up the engine exit cooling water to on
the order of 400C. Once cooled in the heat injector/injection water
pump, the exhaust gasses are ported through secondary intake line
126 to the second stage 130 of the separator system 180.
[0036] The second stage of the separator system 180 provides first
heat recovery as the heated gas and the superheat highly
pressurized water is injected into the heat recovery unit in a
manner describe below. Subsequent to the heat recovery stage,
within the chamber the expansion increases the temperature of the
gas which will drop significantly preparing the components of the
gas for separation of the exhaust stream components, in this
embodiment primarily H.sub.2O, CO.sub.x and argon. Additionally,
the CO.sub.X will, with proper operation of the engine 16 and
variations of fuel, oxygen and argon, be primarily composed of
CO.sub.2 with only trace amounts of CO. Thus, in this second stage,
in the engine heat recovery and gas separator 23 the exhaust gasses
are further reduced in temperature to a temperature on the order of
-50C. In the third stage the cooled gasses are pressurized and at
the same time cooled by liquid nitrogen (See FIG. 6), at which
point the H.sub.2O will precipitate out of the stream as
supercooled water and ice, the CO.sub.2, will precipitate out as a
liquid, and the argon will remain in a gaseous state. To enable
this feature, in this embodiment, two rotary engines are coupled in
series, i.e., the exhaust of one is used as the feedstock for the
second, to cool the exhaust is two stages by expansion while
converting stored energy in the heated exhaust into work or power
output of the shafts of the rotary engines.
[0037] Referring now to FIG. 2, an embodiment of the first rotary
engine 132 of the second stage of the separation system 180 is
shown in section. This rotary engine 132 configuration includes a
generally cylindrical housing 134 having opposed, generally
circular ends 136 (only one shown), in which is mounted on a shaft
138 a generally propeller shaped rotor 140 and a pair of opposed
abutments 142, 144, the function of which is to, in conjunction
with the surfaces of the rotor 140, form four compartments of
variable size within the cylindrical housing 134.
[0038] The operation of the abutments 142, 144 with the rotor 140
is described with respect to the lower abutment 144, as follows.
The lower abutment 144 includes an interior end 146 which is
maintained in very close position adjacent to the surface of the
rotor 140, such as several microns of space therebetween, and a
second end which is extendable through an abutment sleeve 147
extending through the cylindrical housing 134. As the rotor 140
rotates about the shaft 138, the abutment 144 is linearly moved
inwardly and outwardly of the volume in the cylindrical housing
134, always maintaining a very close spacing between the interior
end 146 of the abutment 144 and the face of the rotor 140. Thus, as
shown in FIG. 2, the interior volume of the cylindrical housing is
separable into four portions: An expansion chamber 148, an exhaust
gas chamber 150, a low pressure intake chamber 152 and a gas
compression chamber 154. Additionally, each of the volumes
comprising these chambers 148-154 is communicable with an entry or
exit port extending through the wall of cylindrical housing 134.
Specifically, expansion chamber 148 is communicable with a
combustion chamber 160 through a combustion chamber port 162, an
exhaust port 164 extends from the exhaust chamber 150 to an exhaust
manifold 166, an intake port 168 extends from a supply of engine
exhaust to the inlet chamber 152, into which the fluids and/or
gasses may be introduced to the engine 130, and a compressed gas
inlet 172 is provided to selectively port the gasses compressed in
the compression chamber to the combustion chamber 160 to thereby
introduce the compressed fluids and gasses into the combustion
chamber 160.
[0039] To move the abutments 142, 144 inwardly and outwardly,
abutment controls 180 (184) are provided. Each abutment control, as
shown schematically in FIG. 3, includes a linear stepping motor 182
connected to the abutment 142 (or 144) at a position outwardly of
the chamber volume, and the linear stepping motor moves the
abutment 142 (or 144) inwardly and outwardly of the chamber volume,
such that the interior ends 146 thereof are maintained within
microns of the rotor surface. This is accomplished by controlling
the stepping motor 182 with a controller 184, into which is
programmed the position required for the interior end 182 of the
abutments 142, 144 for any rotational position of the rotor 140.
The rotational position of the rotor 140 may be determined, and fed
to the controller 184, such as with a precision magnetic pickup or
series of the same on the shaft 138 calibrated to the rotor
position. It should be appreciated that as the rotor 140 turns, the
ends or tips 186 of the rotors will pass the abutment interior ends
146, and thus the individual chambers formed within the cylindrical
housing 134 will vary from a maximum to zero, or nearly zero,
volume.
[0040] The rotary engine 130 may be used as an internal combustion
engine, for example, by having the fuel/carrier gas mixture enter
the intake and having the gas for combustion injected into the
combustion chamber, or it may be used as an energy recovery and
exhaust cooling system To use the rotary engine as a energy
recovery system and exhaust cooling system, the exhaust gasses from
engine 16, consisting primarily of CO.sub.2, Argon, and H.sub.2O
from combustion (but not superheated 350.degree. C. engine exit
cooling water) are passed through the heat exchanger and enter the
low pressure intake chamber through intake line 126 which is ported
to intake port 168, thereby introducing the gasses into the low
pressure intake chamber 152. The movement of the rotor reduces the
pressure in the input chamber sucking in the exhaust gas from the
heat exchanger into the chamber. As rotor 140 rotates about shaft
138, it passes over intake port 168, thereby causing no further
exhaust to be taken into the particular volume being drawn into the
low pressure intake chamber 152, and causing the volume to now
exist in the compression chamber 154. This volume of
emission/exhaust is thus compressed, and the exhaust gases
CO.sub.2, Argon and H.sub.2O as the volume of the compression
chamber is reduced as the rotor continues to rotate and as a result
the approximately 500.degree. C. intake gases are heated to high
temperatures. At an appropriate time a valve 173, which is either
electrically controlled or mechanically timed, such as through a
cam and arm arrangement connected to the shaft 138, opens to enable
the compressed exhaust to pass through the compressed gas inlet 172
and thence into the combustion chamber 160. Simultaneously, the low
pressure chamber has reformed as bounded by the abutment 144 and
the opposed side of the rotor 140.
[0041] In order to use this rotary engine 132 as a energy recovery
system and a gas expansion and separation system, a further
modification is needed, in order that the volume achievable in the
expansion chamber 148 and the exhaust chamber 144 are enlarged in
comparison to the volume of compression chamber 154 and low
pressure intake chamber 152. With the high temperature gases
compressed into the combustion chamber, the 400.degree. C.
superheated engine exit cooling water pumped by the pump located in
the Heat Exchanger and Water Pump under modest pressure, 10 Mpa
(1,470 PSI) is pumped into the Pressure Amplification Water
Injection System (22a) with 25 times amplification. The highly
energized water, similar in state to water exiting a steam turbine
boiler enter the combustion chamber, but because the water has been
injected at such great pressure (250 Mpa, 36,750 PSI) the water
enters the chamber as micro size supercharged droplets that
essential explode in the high temperature gas environment. This
explosive expansion pressurizes the combustion chamber followed by
the expansion chamber allow most of the energy to be recovered from
the exhaust gas, and even the exist engine cooling water.
[0042] Referring now to FIG. 4, this is accomplished by modifying
the rotary engine 132, in this embodiment, by providing a partition
188, generally circular in shape, within the chamber body and
parallel to the ends thereof, and providing a rotor of
substantially equivalent cross-section commonly on the shaft 138 in
each of the two sub chambers 190, 192 formed therein. (Abutments
142, 144 have been removed from this FIG. 4 for clarity, it being
understood that such abutments will be present and will operate as
described previously herein in conjunction with both rotor 140 in
sub chamber 190 and rotor 140' in sub-chamber 192. Likewise, the
combustion chamber 160 is not shown, for clarity of discussion.
Thus, rotor 140 is provided in the first sub chamber 190, and rotor
140' is provided in second sub chamber 192. However, in this
embodiment, although an intake port 168 and a compressed gas outlet
170 are provided in communication with the low pressure inlet
chamber 152 and gas compression chamber 154, respectively, of the
first sub-chamber 190, such inlet and outlet are not provided to
the low pressure inlet and compression chambers of the second
sub-chamber. Likewise, the combustion inlet port 162 is not
provided between combustion chamber 160 and the expansion chamber
148' of the second sub-chamber 192, although the exhaust gas
chamber 150 of the second sub-chamber 192 is ported via a separate
exhaust port 164 to the exhaust manifold 166. Additionally, a
bypass cut-out 194 is provided through the partition 188 includes a
bypass cut-out extending therethrough, to enable common pressure to
be maintained in the expansion chambers 148, 148' and in the
exhaust chambers 150, 150'', but not as between intake chambers
152, 152' and compression chambers 154, 154'. As a result, the
volume of the exhaust initially taken up by the engine 162 is
smaller than the volume into which the combination of the exhaust
gas and superheated water expand. In this embodiment, this volume
difference is on the order of three to one, which is provided by
placing the partition 188 one-third of the span of the cylindrical
housing 134.
[0043] As the bypass cutout is a three dimensional feature, i.e.,
it has a perimeter as well as a thickness equal to the thickness of
the partition 188, there is the possibility, and in fact
likelihood, of leakage between combustion expansion chambers 148,
148' and the exhaust chambers 150, 150', and thus an additional
isolation paradigm is needed. To provide isolation, the bypass
cutout 194 is configured to enable a secondary seal to be
interposed between the rotors 140, 140' when the rotors are
simultaneously passing the bypass cutout 194. In this embodiment,
as shown in FIG. 5, this isolation is provided by extending, from
each arm 196, 198, of rotor 140 a secondary wiper 200, which has a
width contoured to the profile of the rotor 140 and a greater than
the width of the bypass cutout 194. As shown in FIG. 5, the
uppermost wiper 200 is depicted in an extended, in the cutout 194
position, and the lowermost wiper 200 is show retracted into the
rotor 140.
[0044] As shown in FIG. 4, the perimeter of the bypass cutout 194
is formed at two radii 201, 202 formed at an angle to each other
and extended from the center of shaft 138 and of arcs formed at two
at two different radii from the shaft. As a result, the wiper 200
is presented with consistently spaced inner and outer radial
surfaces as the rotor 140 passes the wiper in the bypass cutout
194. To achieve extension of the wiper 194 from the rotor end face
202 to engage against rotor 140' and face 202', the wiper 200 is
bias loaded in a conforming slot 206 in the end face 202 of rotor
140. To extend and retract the wiper 200, a cam and lever (not
shown) are preferably linked to the shaft 138, such that the cam is
actuated when the shaft is positioned such that rotors 140, 140'
have just cleared the cutout 194, and secondarily is actuated when
the wiper 200 is about to reach the end of the cutout 194. When the
cam indicates the cutout 194 is cleared by the rotors 140, 140',
the wiper is extended. When the cam indicates the cutout perimeter
is about to be reached by the rotors 140, 140', the wiper 200 is
retracted. To extend the wiper 194 a plurality of springs, or a
pressure bladder may be employed (not shown). To retract, the cam
may cause a rotary cam having a spiral slot therein to engage a pin
extending from the wiper, generally parallel to the partition 184,
to pull the wiper 200 back into rotor 140. The construction and
operation of such cams, arms and retraction devices is well known
to those skilled in the art.
[0045] Thus, when exhaust gas is introduced to low pressure intake
chamber 152, it becomes compressed in compression chamber 154 and
enters combustion chamber 160 where it is combined with superheated
droplets of water. When the combustion chamber 160 is then vented
to the combustion expansion chamber 148, the products of the
combination of superheated water and the exhaust stream expands
also into combustion expansion chamber 148' by flowing through the
cutout 194. Thus, the combined exhaust-superheated water expands,
in this embodiment, into three times the volume the exhaust was
compressed into, to enable the mixture to be substantially expanded
and thereby cooled. Once the rotors have moved to create the
maximum volume of the combustion expansion chambers 148, 148', the
rotor tips pass over exhaust ports 164, 164', and the separated by
phase mixture passes into exhaust manifold 166. Thus, as the rotors
140, 140' rotate, consecutive volumes of exhaust gasses are
compressed, mixed with superheated water, expanded, and exhausted
into exhaust manifold 166.
[0046] In addition to the expansion and consequent phase based
separation of the exhaust components afforded by the engine 132,
the expansion of the exhaust gasses/superheated water mixture
releases energy which is converted to power by virtue of the
expanding mixture pushing on the rotors 140, 140' to cause rotation
of the shaft 138, and likewise supply energy in excess of that
needed to compress the incoming exhaust gasses. Thus, shaft 138 may
be coupled to a generator to generate electricity, or may be
coupled to other work transfer devices, such as a working shaft to
power equipment, motor vehicles, ships, trains and the like.
[0047] Although the exhaust gasses have been cooled in rotary
engine 132, they are still above the condensation temperature of
the CO.sub.2. Therefore, the exhaust manifold 166 of the second
stage rotary engine 132 is coupled to the inlet of an additional
second rotary engine 132', in this embodiment having the
configuration of the rotary engine 132 of FIG. 3 and therefore not
separately described. In use, the exhaust of the rotary engine 132
is input to the inlet of the second rotary engine 132', and
supercooled water is injected into the combustion chamber thereof,
such that upon combination the gasses expand and again drive the
rotors 140, 140' to turn the shafts and thereby produce energy,
while simultaneously expanding the exhaust-water mixture to -50C.
Useful work is accomplished to drive the rotors of this second
rotary engine 132', such that power can be recovered from the shaft
138' thereof.
[0048] Once the exhaust has exited the second rotary engine 132',
it enters the third stage of the separation system 180, in this
embodiment a low temperature compressor, which compresses the
exhaust stream from the second rotary engine 132', and thereby
solidifies the H.sub.2O resulting in each of the three components
of the waste stream into separate phases. These three phases may
then be separated physically, to provide water, argon and carbon
dioxide. Specifically, as the exhaust stream flows through the
compressor 200, the pressure of the fluid increases to the point
where H.sub.2O becomes solid, and the stream is then flowed through
a separator 202 such as a conduit having tines or screening therein
which traps the solid H.sub.2O, and the argon is bled off through a
conduit 204. The remaining CO.sub.2 is flowed out of the compressor
200, and into a storage container 27 (in FIG. 1, via port 206 or
directly to the biomass for the recovery of oxygen therefrom. When
stored in the container 27, the CO.sub.2 may be released, sold,
used to cool the ice water chiller 24 (FIG. 1) on the input side of
the power generator, fed in gaseous form to the biomass, or a
combination of these features. Where used to as a coolant for the
CO.sub.2 air chiller 28, such that air may be passed through the
chiller 28 to be cooled thereby, and thence flowed to the N2 air
chiller 6, which in turn transfers cooled air to the Cryogenic
O.sub.2 separator unit 1 where the O.sub.2 is separated from the
air at about -170C. The H.sub.2O that is recovered is passed to the
ice/water air chiller 24, where air is passed thereover through a
heat exchanger integral thereto, and the water is then routed to
the water tank where it is stored and pumped, by water pump 26, to
the coolant passages of the engine. The argon is returned to the
argon tank 7.
[0049] Referring now to FIG. 7, the conversion of the CO.sub.2 to
form oxygen for reuse in the engine 16, a biomass converter 220 is
provided. The biomass converter is preferably an enclosed algae
field 202, over which the CO.sub.2 is released for photosynthesis.
As photosynthesis progresses, in the presence of sunlight water and
a CO.sub.2 enhanced ambient, Oxygen is released as the CO.sub.2 is
converted to a carbon based mass, i.e., algae. The use of the
CO.sub.2 to provide enhanced algae growth provides synergistic use
of the CO.sub.2, as the algae converts, through photosynthesis, the
CO.sub.2 into carbon based bulk algae and oxygen, and the algae may
be revived and fermented to form methanol for use as a fuel for the
power generator. In this embodiment, the algae field may be
provided by locating algae in a plurality of transparent tubes
composed of glass, plastic or the like, and preferably orienting
the tubes vertically, to increase the quantity of sunlight reaching
the algae. The tubes have opposed ends such that CO.sub.2 is flowed
in at one end such that, as the algae grows, the ambient at the
introduction ends is nearly 100% CO.sub.2, and as the CO.sub.2
flows to the opposed end of the tube, the CO.sub.2 content is
reduced, and the CO.sub.2 content increased. Additionally, water
from the cooling water tank 25 (FIG. 1) may be used to provide
water to the algae field 202 to make up for evaporation or other
water losses therefrom.
[0050] Several methodologies are currently feasible for the
production of fuel from algae. For example, methane may be produced
therefrom via biological or thermal gasification. The biomass may
be fermented, thereby forming ethanol. It may be burned directly.
It may be pressed to release the oils therefrom and those oils may
be transesterified, in which the triglicerols therein are reacted
with a simple alcohol, to form alkyl ester, which is commonly known
as biodiesel. Additionally, it is known that certain green algae
will, when subjected to an anaerobic environment, produce hydrogen,
which may be recovered and used as a fuel.
[0051] Once the oxygen enriched gas stream has passed from the end
210, the gas stream is then flowed to a mechanical filtering system
4 removing some of the nitrogen and CO.sub.2 from the oxygen
emitted from the algae field. Such filter are commercially
available, and while not purifying the oxygen for use it creates an
it is effectively enhance oxygen air with is ported to the Nitrogen
Air Chiller 6 and Air Selection Valve (both in FIG. 1).
[0052] In an additional embodiment, the methanol, ethanol and/or
algae oil streams 13, 15, 17 may be directed to a reformer 219, to
convert the streams into constituent elements, including H.sub.2,
CO.sub.2, H.sub.2O and carbon, as well as an output of power. Each
of these constituents may be reused by being recycled back into the
biomass 202, used as cooling water for the engine, or sold for
value.
[0053] Referring now to FIG. 8, there is shown a table showing the
relative efficiencies of the power generator of the present
invention, in comparison to another power generation scheme,
specifically a gas turbine power generation scheme. In this Figure,
the power generator of the present invention is referred to as an
E.sup.2 engine. Specifically, FIG. 8 compares the electrical
generation efficiency of the E.sup.2 Engine, operating in a diesel
combustion mode as discussed herein with respect to engine 16 being
the combustion engine, with a Combined Cycle Gas/Steam Turbine
system. The Combined Cycle Gas/Steam Turbine system is used as the
reference because it is currently the most efficient commercial
electrical generation system.
[0054] The bottom line comparison can be understood by looking at
the potential efficiency of the power generator hereof. The
potential of the power generator of the present invention is 57%
efficient compared to the Combined Cycle, Gas/Steam Turbine system
which is rated at 55% efficiency. It should be noted that the
bottom line efficiency presented is the efficiency at the user
location. The efficiency takes into consideration transmission
losses at the user location. Because the power generator of the
present invention is a zero emission engine it is possible and
practical for it to be located at a large user location in urban
and even downtown environments. This placement is not acceptable
for Combined Cycle because of the NO.sub.X and CO.sub.2
emission.
[0055] If the transmission losses were not considered an integral
part of the analysis, and in the case of the power generator
hereof, the 1% amount of loss was added back into the output of the
power generator hereof, then the efficiency for some typical large
size engine (on the order of 300 MW) would be 58%, and the
efficiency of the Combined Cycle engine would be on the order of
60%. Thus, one may say that, excluding transmission inefficiencies
the Combined Cycle engine is slightly more efficient than the power
generator hereof.
[0056] However, the comparison between the two engines performed in
the above manner is inadequate because the power generator of the
present invention is a nearly zero emission engine while the
Combined Cycle engine may be clean when compared to conventional
engines, but compared to the power generator of the present
invention it is a major contributor to NO.sub.X and to greenhouse
effects by emitting CO.sub.2. If the Combined Cycle system were to
be modified, and a final stage added to absorb and reduce the
CO.sub.2 release to near zero, this would cost the Combined Cycle
engine an approximate 10% drop in efficiency with no economic means
to reduce NO.sub.X emissions to zero. Thus, the Combined Cycle
system, the most efficient of today's systems, has an operational
efficiency of 50% when normalized to a Zero CO.sub.2 emissions, but
has a major, non-correctable disadvantage in the NO.sub.X emissions
area.
[0057] For comparison, assuming the power generator of the present
invention is using a diesel combustion cycle, which uses the better
current techniques that are achieving approximately 49% efficiency.
The additional use of high-pressure fuel injection amplification
increases the efficiency by another 3% bringing the overall engine
efficiency to (49%+3%) 52%. The higher combustion temperature
resulting from the enhanced O.sub.2 environment and the use of
argon instead of nitrogen increases the overall efficiency of
engine operation by 12%+52%=64%. The energy gain from the
downstream heat recovery in rotary engines 132, 132' adds
approximately another 12% to the overall useful work from the
engine or 12%+64%=76%. The losses in efficiency associated with the
production of reasonably pure O.sub.2, and the separation and
precipitation of Argon, CO.sub.2 and H.sub.2O is approximately 18%,
reducing the overall efficiency or 76%-18%=58%. If the power
generator of the present invention is located at a remote site for
electricity generation, and additional 1% of losses should be
expected, resulting in 58%-1%=57% efficiency.
[0058] In another aspect of the invention, the power generator of
the present invention may be used in two operating modes, a
non-recycling mode, i.e., where the exhaust stream is ultimately
vented to the ambient surroundings and a zero, or near zero,
emission mode. This is useful where, for example, the power
generator is used to power a mobile vehicle, but is also used to
provide power in a stationary location.
[0059] Referring now to FIG. 9, there is shown in Block diagram
form the operational aspects of this dual mode use of the power
generator hereof. In the first operational, Zero Emission mode, the
power generator operates as described in conjunction with FIGS. 1
to 6 herein, with the following changes: To be consistent with the
discussion above, methane or natural gas, with a very low or
effectively zero N.sub.2 content will be the assumed fuel
(Hydrocarbons, C.sub.xH.sub.y, H.sub.2 or C.sub.2 powder mixed with
Argon could alternatively be used). However, the methane or low
N.sub.2 content natural gas will be contained in a relatively small
vessel fuel tank 230 containing sufficient capacity to comfortably
cover a specific distance of normal daily or weekly travel. Instead
of being produced locally, O.sub.2 in vehicle applications will be
stored onboard in an O.sub.2 Tank 232 (except in an application
where space and economy enable the use of on-board oxygen
generation, such as on a ship or train). The quantity of O.sub.2
stored in the O.sub.2 tank 232 will be sufficient to burn, i.e.,
combust with, in the combustion chamber 18 of engine 16 of FIG. 1,
the amount of fuel in the Fuel Tank 230. The fuel from fuel tank
(1) and argon from argon Tank 234 are mixed in the Turbo Mixer 10
and drawn into the engine 16 as described in the figures above. The
mixed gases are combined with the injected O.sub.2 from the O.sub.2
tank 232 in the combustion chamber 18 as described in FIG. 1. The
exhaust gases and the engine cooling water from the engine 16 enter
into the engine heat recovery and gas separator system 23 as
described in the forgoing Figures. However, in the present case,
the H.sub.2O exiting the Heat Recovery/Gas Separation System 23
could be either stored and usefully disposed of after the trip or
released to the atmosphere. The preferred embodiment would be to
release the water into the atmosphere to evaporate into the air
instead of carrying the relatively high weight, low value cargo.
The Argon emitted from the Heat Recovery/Gas Separation System
would be returned to the Argon Tank 236, and the CO.sub.2 would be
returned to the CO.sub.2 Tank 238. The CO.sub.2 storage conditions
could be adjusted to store the CO.sub.2 in solid or liquid form
with the preferred embodiment being the lighter of the two
alternatives. The CO.sub.2 Tank 238 would be sized in a manner
consistent with the sizing of the Fuel Tank 202 and the O.sub.2
Tank 232. The rotary motion of the shafts of the engine 16 and
engines 132, 132' could be used to power the vehicle directly, or
in an additional aspect the engine is used to power a Generator 240
and then a Motor 242 which will be used to power the vehicle in a
hybrid mode known to practitioners of the art. All of the
above-described operations would be under the control of an
Intelligent Control System 250 as will be described further
herein.
[0060] In Operational Mode 2: Standard Driving Conditions. The
above described vehicle engine is used as a standard engine
consuming ordinary available fuels and running with generally
available efficiency and emission levels. In this mode of
operation, Air is moved to the Turbo Mixer 10 instead of methane or
low N.sub.2 level natural gas, and Argon is transmitted to the
engine 16 using the air received and compressing it into the
combustion chamber of the engine instead of the noble gas/fuel mix
as would be the case in Operational Mode 1. The operational
performance of the Turbo Mixer 10 will be adjusted under the
control of the Intelligent Control System 250. It will adjust the
operation to best known control practices as an air turbo engine
feed. Standard fuels such as gasoline or diesel will be fed into
the engine 16 based on the type of engine used, i.e., spark or
compression based. In this mode of operation, the gasoline or
diesel fuel will be injected into the combustion chamber 18 through
a standard readily available 2.sup.nd gasoline or diesel fuel
injection system 244. The standard fuel Injector system 244
parallels the O.sub.2 fuel injection system which is utilized in
Operational Mode 1. Once again, the Intelligent Control System 250
would operate the fuel injection and combustion controls in an
optimum manner. During Operational Mode 2, the engine heat recovery
and gas separator system 23 will be physically and functionally
engaged with the engine 16, and the exhaust gases from the engine
heat recovery and gas separator system 23 would exit through a
standard exhaust system 248 with standard catalytic converters
etc.
[0061] Referring again to FIG. 1, in standard block diagram form an
intelligent control system 250 is operably connected to each of the
operational components of the power generator of the present
invention, as well as to sensors of pressure and temperature
disposed in intermediate locations, such as the inlet manifold of
engine 16, the outlet manifold thereof, the inlets and outlets of
engines 132, 132, the separator 202, as well to the inputs to the
engine 16, such as the water chiller, N2 chiller, etc.
Additionally, the output shafts of the engines 16, 132 and 132'
will include speed and torque pickups, the output of which is
operably coupled to the control system 250. Thus, the control
system receives signals corresponding to the operating conditions
of the engine to enable intelligent choices in fuel-O.sub.2 mixing,
fuel and O.sub.2 supply rates, argon inlet rate, etc. Likewise, the
outlet or exhaust of engine 16 may include one or more sensors
therein to measure the presence and quantity of oxygen, nitrogen,
etc., emitted from engine 16.
[0062] To convert the energy of the fuel and oxygen mixture and
heat generated thereby into useful energy, the output shafts of the
three engines, engines 16, 132 and 132', are preferably linked to a
gearbox 254 or transmission, and then further connected, from an
output shaft of the gearbox, to a generator for the generation of
electricity. The output shafts may be separately linked to the
gearbox 254, or the output shaft of engine 16 linked to one side of
the shaft 140 of engine 132 and the output side of shaft 140 linked
to the input side of shaft 140' of engine 132'. The output side of
shaft 140' would then be linked to the gearbox 254. The gearbox 254
is likewise controllable by the control system 250, such as through
the operation of solenoids or other electrically or pneumatically
operated methods, to change the relative speed of the input(s) to
the gearbox 252 through the interposition of different ones of sets
of gears on the input and output sides thereof. Thus, the speed and
torque of the output shaft of the gearbox 252 may be adjusted to
address changing conditions downstream of the generator and thus
match the output of the generator to electrical loads.
Simultaneously, in this aspect, the quantity of the fuel and oxygen
reaching the engine 16 may be adjusted to increase or decrease the
energy discharged therefrom through its output shaft, thereby
further enabling the matching of the generator 254 to any
downstream electrical load. The output of the generator 254 may be
used to provide local power to a home, building, etc., or it may be
input into the local electric grid. Furthermore, where the power
generator of the present invention is used to power a large mobile
vehicle, such as a ship, the output of the gearbox 252 may, with
appropriate backlash and other drive train components, be directly
coupled to a propeller.
[0063] Although the present invention has been described herein
primarily as used in conjunction with methane as a fuel, other fuel
options are specifically envisioned. Ethane or a combination of
ethane and methane, deliverable to the power generator of the
present invention in gaseous or vapor form, are readily
interchangeable and combinable for intake into what would otherwise
be the "air" intake of the engine 16. The methane and/or ethane are
readily provided from source of natural gas where the source has a
low N content, from natural gas after filtering N therefrom, or
from the algae field. Additional fuels may be used, and if so,
certain modifications may be necessary to introduce them into the
engine 16 combustion chamber 18. For example, diesel fuel or
gasoline having a low nitrogen content, or filtered for a low
nitrogen content, could be introduced to the combustion chamber
through an injector, in which case only argon need be introduced
through the intake manifold.
[0064] Referring now to FIG. 10, there is shown an additional
embodiment of the invention, wherein oxygen and a fuel are
combusted without the use of the carrier gas as described herein
with respect to FIG. 1 to 9. In this embodiment, a turbine 300,
typically configured as a gas turbine 300, is used as the primary
extractor of energy produced in the combustion of a combustion gas,
in this aspect oxygen, and a fuel, in this aspect natural gas.
Referring to FIG. 10, the power generator includes an intake
section 302, in which the oxygen and fuel are preprocessed, a
combustion and power generation section 304 and a downstream
extraction system for the extraction of additional energy from the
exhaust stream, and the separation of the exhaust gas into its
individual components. Additionally, a biomass may be used, in
conjunction with the CO.sub.2 from the exhaust, to absorb the
CO.sub.2 and accelerate biomass growth and to produce via
photosynthesis oxygen which when bubbled through the water exits
the exhaust of the enclosed algae growing environment forming
oxygen enriched air. The enriched oxygen air is fed into the intake
section of the power generator and reducing the energy required to
extract the oxygen need for down stream processing.
[0065] Intake section 302 includes N.sub.2 Air Cooler 308, into
which air from ambient surroundings is introduced and cooled before
the air enters the Cryogenic N.sub.2 Separator 310 after which the
oxygen is introduced to a turbo-mixer 312, in this aspect a
turbocharger. The remaining components of the cooled air, primarily
N.sub.2, H.sub.2O, and CO.sub.2 are then circulated optionally to
the Generator for cooling down the Generator 314 to low
temperatures reducing the thermal loss IR resistance potentially to
zero using superconductor materials. The N.sub.2 may then be
recirculated to the coolant side of the heat exchanger forming the
N.sub.2 Air Cooler 308. Alternatively the liquid N.sub.2 might be
fed directly back to the air inlet side of the N.sub.2 Air Cooler
308. In parallel to the separation of O.sub.2 out of the air
through precipitating out the N.sub.2 and trace components from
O.sub.2 in the air, a similar operation takes place with the
natural gas, wherein the natural gas is fed into a separator,
likewise a heat exchanger in which the natural gas is fed through
one side thereof, and a liquid having a temperature below the
boiling point of nitrogen is flowed through the other portion
thereof, such that nitrogen and natural gas without nitrogen are
recoverable therefrom in separate streams. Natural gas enters and
is pre-cooled in the N.sub.2 Natural Gas Cooler 316 before entering
the Cryogenic N.sub.2 Separator 318 where the N.sub.2, H.sub.2O and
CO.sub.2 and other low liquefaction trace elements are separated
from the natural gas fuel elements mostly methane and ethane. The
liquid N.sub.2 and other trace elements are then circulated
optionally to the Generator 314 for cooling down the Generator 314
to low temperatures thereby reducing the thermal loss IR resistance
potentially to zero using superconductor materials and then feeding
back the N.sub.2 coolant to the N.sub.2 Air Coolers 308, 316,
alternatively the liquid N.sub.2 might be fed directly back to the
N.sub.2 Air Cooler 308, 316. The O.sub.2 emanating from the
Cryogenic N.sub.2 is fed into the Turbo Mixer 312. Alternatively
the separation of N.sub.2 from both the O.sub.2 in the air and from
the natural gas can be all made using one pre-cooler station and
one Cryogenic Separator for the two functions. However for safety
reasons and certain optimizations that may be possible by uses
separate paths the preferred embodiment is describes two separate
channels for separating out the N.sub.2.
[0066] The cold O.sub.2 and natural gas are fed into the Turbo
Mixer 312 in correct proportions and from there into the Burner
320. The high temperature high pressure gases, higher temperature
are then passed through the Gas Turbine 300, in the usual manner
producing torque to turn the Generator 314, the exhaust gas from
the Gas Turbine 300 is fed into the Heat Exchanger and Steam
Turbine 322 which services as a heat recovery system adding to the
Generator 300 torque. An Optional third stage Low Temperature Heat
Exchanger and Turbine 324 is shown. A Gas Turbine Combined Cycle
system normally would not have a third level heat recovery stage.
However the most preferred configuration feeds the CO.sub.2 and
H.sub.2O into an associated algae growth environment as described
in FIG. 7 hereof with necessary modifications in temperature
control and other issues which are obvious to someone skilled in
the field. In this embodiment it is required to have the CO.sub.2
and H.sub.2O enter at relatively cool temperatures, therefore it
may be economically advantageous as part of the process to add what
would normally be considered an added heat recovery stage to the
system. The power generator of FIG. 10 is also provided with a
control system, the operation of which was described with respect
to FIG. 1 hereof.
[0067] Use of the Power Generator for "Solar" Applications
[0068] The power generator of this aspect is also suitable for use
in conjunction with SEGS, wherein the power is generated with the
same or similar, low emissions resulting from solar energy.
Likewise, where a solar facility, such as the SEGS facility
employing simple boiling, is used in conjunction herewith,
simultaneous power generation with the fuel and solar generation
can result in a net doubling of output power and may be
accomplished economically during peak generating requirement
periods. Another aspect in order to meet the established criteria
of being considered a solar power station of double the initial
capacity for purposes of being classified a SEGS plant it is
necessary to be able to operate the entire double capacity at least
for some period of time. With the aspect of the algae field and
algae produce clean solar burning this could be accomplished simply
by running one full set of capacity on algae solar fuel. In the
absence of algae solar fuel, the plant could be run as a double
plant by storing sufficient heating fluid, so that for some portion
of the peak hours, one full rated steam turbine could be run from
the solar field heating fluid flow, and the other could be run from
the stored heating fluid.
[0069] Where, as described with respect to FIG. 10, 100% O.sub.2
and fuel mix is used to power a gas turbine there are benefits from
reduction in CO, NOX, and other emissions with marginal reductions
in emissions and efficiency and a meaningful increase in power. In
FIG. 10 the N.sub.2 is shown to be removed from the natural gas by
precipitating the nitrogen at the liquefaction temperature of
N.sub.2 or somewhat lower. N.sub.2 appears in normally available
natural gas deposits at levels of mere trace quantities to
quantities in excess of 15%. The form of filtering the unwanted
N.sub.2 out of the natural gas as described with respect to FIG. 10
at the same time lowers the temperature of the input gas, which is
desirable for efficiency and power output reasons. In a similar
manner the N.sub.2 is removed from the O.sub.2 in the air by
lowering the air temperature to the levels required to liquefy the
N.sub.2 and precipitating it out from the oxygen in the air. The
lower temperature of the natural gas and the O.sub.2 combined with
the elimination of the nitrogen allows large quantities fuel and
oxygen to enter the compressor (turbo mixer 312), at lower
parasitic losses than with less combustible substances in normally
operations. This filtering method also has the added effect or
lowering the temperature of the O.sub.2 into the combustion cycle
which positively impacts the efficiency and power output of the gas
turbine. The same method for separating the N.sub.2 from the both
the natural gas and the air can be used in power generator
described in FIG. 1. Alternatively the methods described in FIG. 1
of lowering the temperature of air to low enough temperatures to
first precipitate out the N.sub.2 in the air and the liquefy the
O.sub.2 so that it can be handled more efficiently down stream as a
liquid, and a corresponding process of lowering the natural gas to
liquefy the natural gas and gain down stream benefits associated
with handling the fuel as a liquid can be applied as alternative
means of supplying fuel to a Burner 320, through an alternatively
designed pre-combustion liquefied natural gas, liquefied O.sub.2
mixing and fuel injection systems. The various designs may be
alternatively considered in different circumstances, especially
considering much natural gas is being shipped in liquefied form.
This near zero to zero emission combustion technique may be used to
establish the plants near the unloading facility of the liquefied
natural gas and thereby benefit from the energy and capital
expenses already being applied to liquefy the fuel source. In
addition to the liquefaction methodology, mechanical filtering out
of N.sub.2 from natural gas and from O.sub.2 in the air are
possible, the latter are being evaluated in the automotive field in
enhanced oxygen combustion testing.
[0070] The reduction of NOX, CO, and other emissions to effectively
zero emission levels allows the emission of these engines to be fed
into algae and another growth processes to accelerate the growth
cycle feed gases from less clean system could have possible
negative effects with unacceptable toxin levels along with the
useful and positive impact it should have on accelerating
growth.
[0071] Where, as is described herein with respect to FIG. 10, a
100% O.sub.2 and fuel mix is used to power a gas turbine, there are
benefits not only from reduction in NOX and CO, but with improved
uniformity in over the year output capacity of the system which is
quite advantageous in certain applications. This configuration may
substantially increase the power emanating out of a same size
turbine and burners system using traditional air fuel mixtures in
standard gas turbine and combined gas turbine systems. The system
does this compared with conventional competing combined cycle
gas-steam turbine systems with marginal changes in efficiency which
at times are positive and at times negative depending on precise
designs of the two systems.
[0072] The gain in power output capacity stability results from the
fact that in standard gas turbines and combined cycle gas-steam
turbine systems efficiency and power are based to a large extent on
the input ambient and the combustion temperature of the system.
Changes in operating temperature not only change the theoretical
thermal efficiency in addition they effect plant design, which is
optimized for one operation condition or another. While the
combustion temperature is usually fixed at optimized levels for the
system, the ambient temperature can change between day and night
and between summer and winter by as much as 50.degree. C. or more,
thereby varying the output of the plant by 2% to 4%. An inlet
temperature dependent drop in output capacity thus typically occurs
during the summer months during the daytime hours. These happen to
be precisely the hours when many regions require the maximum output
from their plants to meet the need of summer air conditioning. This
summer air-conditioning load sets the requirements for new plant
acquisition, usually inexpensive, low efficiency and relatively
high emissions plants just to produce electricity to meet these
needs.
[0073] There are gains and losses with respect to efficiency of the
power generator hereof using a 100% O.sub.2--fuel combustion system
compared with competing combined cycle gas-steam turbine
technology. As stated previously, on balance the two systems would
run at about the same overall efficiency depending on precise
design factors. This aspect of the power generator system loses
certain operating efficiency by cooling the incoming fuel to
precipitate out the N.sub.2 from the combustion process, on the
other hand the colder temperature of the incoming O.sub.2 and
natural gas reduces the parasitic losses of the air fuel intake
turbocharger and/or compressor feeding the combustible mix to the
burner and then to the turbine. The elimination of the N.sub.2 as a
working gas and which was not a combustion gas in the combustion
cycle would for a the same quantity of gas/unit time entering the
combustion cycle, now composed of, for example, only fuel and
O.sub.2, would produce substantially more heat per unit of time.
Thus as a practical matter the quantity of O.sub.2 and fuel
supplied into the system per unit of time would not be made to
fully substitute for the quantity of N.sub.2 eliminated. But from
the preceding it can be seen that increases of temperature and
pressure are possible and clearly without the negative factor of
added NOX generation. This increase in operating temperature and
pressure will have a tendency to increase the efficiency of the
system. The increased temperature and pressure increase the
efficiency of the system.
[0074] Where the power generator uses a 100% O.sub.2 and fuel mix
and a conventional steam turbine recovery as the second stage of
heat recovery, the only difference in this application to standard
steam turbine heat recovery methods is that the operating
combustion temperature and pressure would be somewhat higher and as
a result, the input emission gases into the Heat Exchanger and
Steam Turbine 232 would be somewhat higher and the temperature of
the exit gases would be somewhat higher. Under standard operations
not in conjunction with the use of an algae field for oxygen and
biomass production, power generator would exhaust the gases from
the steam-turbine to the atmosphere which would be non-toxic, all
NOX essentially eliminated with other trace compounds, but CO.sub.2
would be released along with water. If it is desired to eliminate
the CO.sub.2 and/or gain the other operational benefits from site
produced fuel then it is necessary to feed the emission gases,
CO.sub.2 and H.sub.2O into the enclosed algae field. To do so it is
desirable to cool the output emissions further and to recover some
additional energy out of the waste exhaust heat. This can be
accomplished using a Low Temperature Heat Exchanger and Turbine 324
such that the exhaust gases from the steam turbine boil Freon in a
liquid state converting it to a gas state and drive a low
temperature Freon gas driven turbine. Other gases and
configurations are possible.
[0075] The power generator of FIG. 10 allows the construction of a
combined cycle gas-steam turbine power plant to be used for
converting solar produced thermal energy and certain amounts of
natural gas to electricity, instead of using a steam turbine for
converting the solar produced thermal energy and associated gas to
electricity. The movement from a steam turbine to produce
electricity to a combined cycle gas-steam turbine increases the
conversion efficiency of the plant from approximately 40%+
efficiency to 60%+ efficiency. The power generator, together with
the algae, forms a new solar generation technique meeting the
statutory requirements of solar power generation. The power
generator is a solar facility when the power generator (10) is run
on algae derived fuel. This is appropriate because the fuel which
powers the system comes from the incident sunlight energy and when
this fuel is run in the power generator (FIG. 10) it produces clean
energy, as clean as or cleaner than conventionally powered SEGS
plant which over the years been classified as solar facilities. The
power generator (10) fueled by algae solar fuel and allocated gas
allowances may be cleaner than standard powered SEGS even though
the prior art powered SEGS may burn less fuel annually because when
the SEGS burns its allotted fuel it releases standard levels of NOX
and CO, and other emissions, whereas the power generator (FIG. 10)
burns more fuel during the year but with essentially zero emission
level. Thus in the process algae fuel may be considered as a solar
fuel, a intermediate stage in the solar electrical generation
process. The algae produced fuel, say methane (the principle
component in natural gas), would be used to power the gas turbine
at from 2000.degree. C. to 2500.degree. C. These temperature as
pointed out above are not attainable by commercially feasible
non-biomass solar technology. The high temperature gas emanating
from the gas turbine in turn is used to power the steam turbine.
Thus the full capacity of the gas turbine plant can be run by solar
alone and this allows classifying the full capacity of the plant as
being solar and it does so in a natural and elegant manner. The
prior art SEGS provided a clean (effectively) zero emission power
generator, but could only, in commercial applications, produce
temperature far below the levels required to run the Combined Cycle
Gas-Steam turbine, and thus are unable to use the more efficient
thermal to electrical conversion technology in their facilities.
Once a facility as described herein with respect to FIG. 10 meets
this minimal algae combustion burning time (i.e., run as solar for
a specific period of time) the power generator (10) would be
permitted to burn its allocated fossil fuel limits, and as much
algae solar fuel as desired.
[0076] Where the power generation scheme described with respect to
FIG. 10 is used to produce energy at a solar facility during the
peak sun hours to meet peak user demand, the solar plant may
provide a doubling of solar thermal output during peak hours simply
by adding at very low cost a steam turbine and interconnection
transformer and controls to the grid. Under the current invention
the fuel burning would be considered a solar activity with the
algae being provided as a solar fuel, as a minimum to meet the
statutory requirements and perhaps for more extensive periods of
time provided the cost of algae produced fuel is equal to or less
than alternative commercially produced fuels.
[0077] It can be seen that the peak output of the basic initial
SEGS station would be on the order of 5.5 times greater when
converted into a power generated (FIG. 10 plant) with an associated
algae field. The election to build this higher peak power plant
instead of a conventional SEGS 9 only adds marginally to the
capital cost, both for the solar field and power station. This
combined improvement comes from two factors which are described as
follows: Assuming the "name plate capacity" of the basic SEGS plant
is defined as 1 SEGS output unit. During on peak hours, the waste
heat of the gas turbine would be used to power the primary stations
steam turbine. The gas turbine produces approximately 2 SEGS output
units. The 2 to 1 ratio is generally the standard gas to steam
turbine ratio. The SEGS solar field during this on-peak operation
would power a separate steam turbine which would operate only
during the on-peak hours and produces an additional 1 SEGS output
unit. Thus from the initial SEGS steam turbine we get 1 SEGS output
unit, from the gas turbine we get 2 SEGS output unit, and from the
auxiliary on peak steam turbine we get 1 SEGS output unit, or
altogether 4 SEGS output units. However in addition during the peak
power period when the solar plants are operating as a combined
cycle gas-stem plant is operating at 3 times normal output, the
efficiency is approximately 50% higher from the bottom up, the 3
SEGS output units would be on the order up to 4.5 SEGS output units
plus the 1 SEGS output unit for the plant working in the strictly
solar mode. The amount of algae produced solar fuel that would have
to be introduced into combustion cycle will need to sufficient to
assure that all peak power needs are met with a reserve for none
solar days without exceeding the 25% fuel burning limitation
imposed by some funding agencies to maintain funding and other
incentives for solar generation and covered with comfortable margin
the full peak requirement.
[0078] It should be appreciated that the power generation scheme
provided as described with respect to FIG. 10 is readily adaptable
to be combined in several ways with a solar generation plat, such
as a SEGS plant. For example, the power generator may be used to
feed exhaust of the gas turbine to the steam turbine, while the
SEGS solar facility can simultaneously, or at separate discrete
times, supply superheated water from its storage tank to the steam
generator, and thereby greater use of the investment of the
facility is accomplished, with greater energy output. Likewise, the
fuel used in the burner may include up to 25% fossil fuel in
conjunction with, or separate from, the biomass fuel. Additionally,
the biomass fuel may be recovered directly from an adjacent biomass
field and facility, or recovered from a remote location and shipped
or otherwise transported to the generation facility.
[0079] Use of the Power Generator for Low Emission Applications
[0080] In addition to the use of power generators of the present
invention for solar generation, the power generator of the present
invention, in particular the embodiments of FIGS. 1 to 6 hereof,
may be produced for vehicle-sized engines to very large power
system sizes. The power generator hereof, when operated in the
manner described, produces energy and power at higher efficiency
and lower emission levels, and at a higher reliability than
competing diesel and gas turbine systems. The power generator of
the present invention differs from existing state of the art
combustion engines in the following important ways:
[0081] Most engines burn fuel in normal air environments using the
approximately 21% oxygen level in the air to enter into a chemical
reaction with the selected fuel. The power generator of the present
invention uses enriched O.sub.2 combustion.
[0082] A diesel engine as described with respect to FIGS. 1 to 6
hereof uses enriched O.sub.2 combustion which would begin with a
35% O.sub.2, 65% Argon mix, and then the mixture would be modified
to optimize the engine performance, probably increasing the
percentage of O.sub.2 to Argon as more familiarity and experience
with control is gained. The first described embodiment uses Argon
as the noble gas and uses an O.sub.2, Argon (Ar) fuel mix as a
combustion environment rather than an O.sub.2, N.sub.2, fuel mix,
which occurs when air is used. The gaseous mix with Argon, instead
of N.sub.2, reduces NO.sub.x emissions to near zero, the quantity
limited only by the level of purity of the fuel for no nitrogen
therein, and any leakage of ambient air into the system. The result
is a near zero undesirable emissions engine instead of a zero
emission engine because, as a practical matter, trace amounts of
nitrogen will remain in the O.sub.2--Ar mix, and as a result, some
portion of the trace amounts of N.sub.2 will oxidize in the
combustion process. Also, small amounts of N.sub.2 will most likely
appear in most of the fuels used. Careful handling of the O.sub.2
and Ar separation and mixing process, and careful selection and
handling of the fuels, should allow N.sub.2 in the system to be
reduced to less than 1% of the amount found in the standard
combustion process.
[0083] The 35% O.sub.2/65% Ar mixture benefit not only reduces
NO.sub.x emission, it also increases engine output power above a
factor of two and further increases efficiency. Note that the
invention is not limited to a 35%/65% mix. Various mix ratios are
possible and the optimum point will very from engine configuration
to engine configuration. There will be a tendency to improve
performance by increasing the O.sub.2 to Argon ratio. The 35%/65%
ratio is used because of the published experience, as set forth in
the background hereof, of diesel engines operating in 35% O.sub.2
enriched air environments, but one skilled in the art will
appreciate that other ratios may be appropriate. The use of the an
O.sub.2/Ar mixture provides another efficiency improvement due to
the presence of Ar, noble (mono-atomic) gas in the combustion cycle
gases instead of a di-atomic compound like N.sub.2, where a portion
of the energy produced is lost in the excitation of the duo-atomic
N--N bond. The combustion efficiency associated with this
substitution increases on the order of 12% (for a 65% Ar
substitution for N.sub.2). This efficiency gain results from
removing the di-atomic gas, which itself absorbs approximately 12%
of the combustion heat and wastefully throws the absorbed heat into
the atmosphere, without expending the thermal energy on useful
work. The single Ar atom does not suffer from heat absorbent
internal oscillation between the di-atomic compounds and does not
produce losses associated with the inter-atom oscillation. The
result is a proportionally higher available efficiency engine.
Additional gains will also be achieved due to higher operating
temperatures.
[0084] Using a highly enriched oxygen environment in the combustion
chamber assists in efficiency because it results in higher
combustion temperatures and increases power because it allows
greater amounts of fuel to be burned in each combustion cycle.
However, the higher temperature and pressure creates certain
instability in the combustion cycle. This invention overcomes these
instabilities by utilizing multivariable modeling and control
techniques that model the combustion timing, uniform expansion, the
useful contribution of each combustion cycle to the uniform forward
movement of the engine, the completeness of combustion, etc. The
models are updated on the basis of ongoing testing (Design of
Experiments, DOE) and normal running operations on the engine as a
whole. Design of Experiments models each cylinder, and/or expansion
chamber, and/or mixing chamber, and/or fuel variant that is used
throughout the intake system through the fluid handling system,
through the combustion cycle, through the heat recovery, and the
exhaust systems. These models are then used to optimize the
operation of the system as a whole by controlling the state of the
composite collection of lower level subsystems to achieve the
overall optimized control objectives based on historic
understanding collected from the data and mathematical
extrapolations. This invention utilizes the public domain modeling,
control, and optimization techniques like neuro-nets and genetic
algorithms, and the InSyst proprietary yield optimization
technology (patent number) to control, stabilize, and optimize this
cycle and system inclusive of its collection of subsystems.
[0085] In order for the exhaust gases to be as emission free as
possible, the lubricating oil used between the cylinder and the
piston, which enters the combustion cycle, must be eliminated. To
accomplish this, an exceedingly low friction, long lasting,
precision cylinder and piston surface are desirable. Such materials
like alumna oxide and/or diamond coated alumna oxide may be
employed. While the power generator hereof based upon engine 16
operating as a diesel engine is able to work without the low
friction piston and use lubricants instead, as is traditionally
done without affecting the efficiency objectives, the inclusion of
the lubricant would somewhat increase emission levels and make it
more difficult to obtain or meet a possible statutory zero emission
standard.
[0086] While heat recovery cogeneration systems are commonly used
in conjunction with gas turbines these systems are not commonly
used in conjunction with internal combustion engines, especially
diesel engines, because the high percentage of useful energy
extraction results in relatively low temperature of emission gases,
which is not typically converted at economically worthwhile costs
into additional electricity. The power generator described herein
is applicable for both internal and external combustion engines.
However, in this invention, unlike standard internal combustion
engine applications, the heat recovery and gas separation system is
an economically useful part of the system as a whole. This is true
in part because of the inventive use of the heat recovery system as
both a heat recovery system and a gas separator, in part due to the
higher temperature of the exit gases of the engine because of the
higher temperature combustion cycle, in part because of the need to
recover the Argon from the exit gases and re-circulate it back into
the combustion cycle, and in part because of the high value in the
preferred embodiment of using the CO.sub.2 exiting the combustion
cycle to accelerate growth of algae, which in turn is used locally
to produce fuels for the engine itself. When fuel is burned in an
O.sub.2/Ar gaseous environment, the post combustion exhaust gases
consist of mostly Ar, H.sub.2O (water), CO.sub.2 and small amounts
of unburned O.sub.2. Because Ar is costly and not readily
available, the power generator hereof includes an integral means
for extracting the Ar from the exhaust gases, and allows the Ar to
recycle into a new combustion cycle. The heat recovery system Stage
1 of the Heat Recovery and Gas Separation System extracts heat from
the exhaust gases through volumetric expansion. Stage 2 of the Heat
Recovery and Gas Separation System receives the reduced temperature
gases from Stage 1 and through additional volumetric expansion
reduces the exhaust gases from Stage 2 to temperatures below
-40.degree. C., typically on the order of -50C, the liquidification
level of CO.sub.2, and much below the liquidification level of
water. Stage 3 of the Heat Recovery and Gas Separation System (FIG.
4) separates the three substances into Ar, which remains in the
gaseous state, water, which largely becomes ice and the CO.sub.2
which is largely liquid through a heat exchanging and compression
process. The separation is done by taking advantage of the phase
and weight differences through a multiplicity of available means.
The water would precipitate from the exhaust gases and allow the Ar
to be recycled into future combustion cycles. The CO.sub.2 and
water from the flue gases can in turn be separated. The cold/ice
water can be used to satisfy certain local power generator needs,
such as cooling of the engine 16. The preferred use of the CO.sub.2
is to feed the algae in the enclosed and controlled algae field,
where the algae are grown and thereafter processed into fuels for
use in the power generator hereof and other applications. In the
absence of associated algae fields other commercial uses for the
CO.sub.2, like use in beverages and other uses, will be found so
that the CO.sub.2 production from the engine does not contribute to
increases of CO.sub.2 into the atmosphere. The Argon emanates from
the Gas Separator in a gaseous state and is circulated back to the
Argon tank and used in future combustion cycles. The relatively
small heat recovery system separates the three exhaust gases: Ar,
CO.sub.2 and H.sub.2O through a combination of phase change, weight
separation, etc. While the system utilizes a small volumetric heat
expansion system, commercially available heat recovery systems and
gas separations systems may be alternatively used.
[0087] A preferred embodiment would involve using the CO.sub.2 to
feed through a piping system algae farm in the general vicinity. In
this embodiment, it is envisioned that the oxygen emanating from
the algae farm would be filtered out and piped in to the power
generator site where it would be compressed and cryogenically
cooled. Any CO.sub.2 mixed into the O.sub.2 would be separated and
fed back to the algae farm through a return piping system. The
O.sub.2, together with any O.sub.2 cryogenically separated from the
air, would be placed in a tank for use in future combustion cycles.
The algae at the algae farm would be processed into fuel and piped
to the engine.
[0088] When the fuel produced from the algae or other agricultural
process refinement is H.sub.2 instead of methane, ethane, methanol,
ethanol, or an algae derived oil, and the H.sub.2 is used as the
source of fuel for the power generator of the present invention,
then CO.sub.2 is a waste product of the H.sub.2 production process
and is in turn fed back into the algae growth cycle. The power
generator using H.sub.2 as fuel would operate on a simpler cycle
mixing H.sub.2 with Argon as a working gas-fuel mix. The heat
recovery system design described above can be simplified making it
necessary only to precipitate out the H.sub.2O and re-circulate the
Ar into the combustion cycle. Alternatively, or in addition, the
H.sub.2, which is a processed refined fuel product of the algae
growth process, can be used as a fuel in other more conventional
fuel cell applications.
[0089] Vehicles, including cars, trucks, trains, and/or ships,
could also be equipped with the power generator hereof. The power
generator hereof used in vehicles can use any clean fuel. A clean
fuel is a fuel that contains hydrocarbon substances with, at most,
trace quantities of sulfur, nitrogen, and other potentially
polluting substances. Filters may be placed between the fuel tank
and the fuel injection system to filter out unwanted substances if
the fuel is not sufficiently clean. The fuels can be either liquid
or gas. If the fuel is a gas, it is mixed with the Ar as shown in
FIG. 1, block 10. If the fuel is a liquid, it is injected into the
combustion chamber through a high-pressure amplification fuel
injector system, which would be set up in parallel with the
pressure amplification liquid O.sub.2 injection system. If
hydrocarbon fuels are used, then the Heat Recovery and Gas
Separation System will recover Ar, CO.sub.2 and H.sub.2O by
precipitation out of the exhaust gases. Alternatively, the power
generator of the present invention may use H.sub.2 as a fuel, like
a fuel cell, by either storing H.sub.2 on the vehicle or by using
more conventional fuel on board and passing the fuel through a
reformer and producing H.sub.2. Once available, the H.sub.2 used in
the combustion operation is mixed with Ar, and thereafter passed
through the Turbo Mixer and then fed into the air manifold and of
the engine 16. In such a case, the Heat Recovery and Gas Separation
System might be simplified. It would be designed just to
precipitate out H.sub.2O and re-circulate Ar in the combustion
cycle, significantly reducing the difficulty of the gas separation
problem, and requiring temperatures to be dropped not far below
ambient levels. When H.sub.2 is used instead of hydrocarbons as
fuel the power generator hereof would be a substitute for a fuel
cell type of application where the fuel for the fuel cell is
produced on board the vehicle. The vehicles so equipped would, as
opposed to fuel cells, have O.sub.2 and H.sub.2, and optionally,
CO.sub.2 storage tanks available for some defined range of travel,
where the CO.sub.2 from the reformer is passed through the Heat
Recovery and Gas Separation system and stored. In one aspect, the
range of travel based on on-board storage vessels would be sized
for standard daily travel. This is sufficient, for example, for
travel back and forth from home to work but not more. For travel in
excess of these distances, the storage tanks are equipped to handle
more conventional fuels, ideally, using low or zero sulfur and near
zero nitrogen containing diesel fuel. In addition, during the
long-term trip mode of operation the power generator would use a
conventional air intake and a parallel conventional exhaust system
within the existing infrastructure for refueling. This would be
environmentally competitive with other similar conventional mode
engine times. It would also be environmentally clean for the more
frequent and higher emissions, stop-and-go city travel. It is
specifically contemplated that such a vehicle would operate either
as a conventional vehicle or as a hybrid vehicle using the engine
to produce electrical energy, which is used in conjunction with a
battery to power the vehicle.
[0090] In one embodiment, the vehicle equipped with the power
generator of the invention, operating as a zero emission or near
zero emission engine, would be connected to O.sub.2 supply, natural
gas input supply, and a piping system which transports the
separated CO.sub.2 to locations where the CO.sub.2 can be used for
algae or other vegetation growth applications, or collected and
distributed to a place or places where it can be used, thereby
off-setting alternative CO.sub.2 production requirements. Such
interconnection systems could be set up at home, work, shopping
center parking facilities, or the places where vehicles are parked
for extended periods of time. At the locations where fuel, O.sub.2,
and collection of CO.sub.2 facilities are available such vehicles,
which are running at very high efficiency, and at essentially zero
emission levels, could supply electrical power to those facilities
in a very reliable manner and at very low cost.
[0091] While the foregoing is directed to embodiments of the
present invention, other and further embodiments of the invention
may be devised without departing from the basic scope thereof, and
the scope thereof is determined by the claims that follow.
* * * * *