Note: Descriptions are shown in the official language in which they were submitted.
CA 02745009 2011-06-20
Steam-Generator and Gas-Compressor Systems
Usin
Water-Based Evaporation Coolants, Sealants and Lubricants
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The subject invention pertains to the use of moderate-to-low-RPM, twin-screw,
rotary gas/air compressor system with continuous, water-evaporation cooling of
a gas
throughout all or part of it's compression cycle. The compressor system may
use an
inorganic, water/mineral slurry, or a non-combustible, organic lubricant
emulsified into a
water base, as an evaporative coolant, and a compression-cavity's partial
sealant and
lubricant. For compression of air, oxygen, oxygen-enriched air, or other
combustion-
support gases, sealants or lubricants must be of non-combustible and non-
reactive
materials. Such materials may consist of a water dispersion of inorganic
minerals, like
bentonite and related clay minerals, colloidal glacial silt, silica gel, mica,
etc., a water
dispersion of synthetic, inorganic, spherical particles,. acting as micro-ball-
bearings, or a
non-combustible lubricant, colloidally dispersed or emulsified into a water
base. The
water in such sealant and lubricating dispersions will undergo continuous and
rapid
evaporation, and must be replaced by continuous water injection in order to
maintain
sufficient slurry sealant and lubricant consistency and volume. The compressed
outlet gas
consists of the inlet gas composition plus the commingled volume of steam
created by the
evaporation of water used for this continuous evaporative cooling.
The subject gas/air compressor system is designed to compress a moderate-to-
high-temperature, moderate-to-high-pressure, thermal-energy carrier fluid
(TECF). From
the compressor system, the TECF carrier fluid may be transmitted to a series
of injection
wells and then into underground permeable geologic zones for production of in-
situ-
retorted-and-hydrocracked products derived from fixed-bed carbon deposits
(FBCD), such
as oil shale, volatile coal beds, tar sands, heavy-oil deposits, carbonaceous
shale, etc., with
such products produced through a series of production wells.
The subject gas/air-compressor system may be designed to use saline-water
solutions with a controlled rate of increasing dissolved minerals in the
evaporating-water
-1-
CA 02745009 2011-06-20
solution without leaving any precipitation or scaling deposits within the
compressor.
Furthermore, the water solutions, with increased-dissolved-mineral content
exiting from
such a compressor system, can be depressurized in a manner to control the
precipitation of
mineral salts for possible recovery of valuable mineral by-products.
(b) Discussion of Prior Art
Heretofore, prior gas-compression technology has generally used multiple
stages
of near adiabatic gas compression with inter-stage coolers to control
compressed-gas
temperatures. Such inter-stage coolers generally use heat-transfer coils of
coolant to
provide the transfer of thermal energy of hot, compressed gas through the
walls of such
coils and into an independent, circulated coolant. However, a water-injection,
evaporative-cooling technology can be used in such inter-stage coolers between
the near
adiabatic compression stages. Also, centrifugal turbine compressors or axial-
flow turbine
compressors have been commonly used for such near adiabatic-compression stages
with
inter-stage cooling.
None of the above mentioned, prior-art, compressed-air-and-gas technology
specifically uses compression systems with a continuously injected, liquid-
water phase to
provide internal, water-evaporation cooling in the compression process. If
limited-
volume, internal-water-evaporation cooling is attempted in centrifugal turbine
compressors, or in axial-flow turbine compressors, mineral-salt precipitation
and scaling
would occur unless very pure mineral water is used.
SUMMARY OF THE INVENTION
This patent application covers several independent but related embodiments or
inventions briefly described as follows:
1. Water-evaporation cooling of any gas during any or all portions of the gas-
compression process in any gas-compressor system resulting in the evaporated
water
(steam) being commingled with the original gas being compressed.
2. The use of non-potable, brackish, saline water for water-partial-
evaporation
cooling with surplus water volumes whereby only a portion of the water is
evaporated in
any part of the compression cycle of any compression system, and the non-
evaporated
portion of the water retains all of the dissolved minerals in an increasing
concentration for
disposal or for processing to extract a mineral byproduct. This prevents the
precipitation
of minerals or scale inside the steam generator/compressor. Consequently, it
is not
-2-
CA 02745009 2011-06-20
necessary to use mineral-free, pure water for this steam-generator, water-
evaporation-
cooled, gas-compressor system.
3. A preferred embodiment of such a steam generator and gas compressor is a
twin-
screw, rotary compressor which includes a compressor housing with a male screw
rotor
having helical lobes received in helical grooves in a female screw rotor. The
housing
includes a gas/air inlet and a series of water-based fluid injectors for
injecting the water
onto the rotating-screw rotors. Also, the housing includes a gas/air outlet
for discharging
the compressed steam and gas into areas of compressed steam/gas application.
4. The use of a surplus of water injected into a twin-screw rotary compressor
to
provide some surplus, non-evaporated water to remain in liquid form to collect
in pools of
liquid water at the bottom of each progressing cavity. The bottom of each
progressing
cavity is where the male rotor is fully engaged in the female rotor with the
liquid-water
pool providing a liquid-sealant barrier to prevent compressed gas from leakage
out of one,
progressing, compression cavity and into the next, lower, gas-pressure
compression cavity.
5. The use of controlled, partial evaporation of the injected water volume of
a non-
potable, brackish or saline water into a progressing-compression-cavity, twin-
screw, rotary
compressor with the residual, non-evaporated water collecting as a liquid-
water-pool
sealant at the bottom of each compression cavity. Such non-evaporated-liquid-
water pool
contains all of the dissolved minerals with increased, dissolved-mineral
concentrations for
either disposal or for precipitation and/or extraction of valuable mineral
byproducts.
6. The use of the steam-generation/compression process described in Item 5
above
for the production of high-value, freshly distilled water from the partial
evaporation of salt
water or brackish water followed by the condensation of the evaporated water
(steam) to
achieve effective desalinization of such non-potable, saline/brackish water.
7. In a further preferred embodiment of this invention, the injected-water,
evaporation coolant may contain a water-mineral slurry or a non-combustible
lubricant/water emulsion to provide improved cavity sealant capability and
better
lubrication of moving parts to increase the efficiency and effective life and
maintenance of
these steam-generator and compressor systems. Such water/mineral slurry may
consist of
a dispersion in water of bentonite and/or related hydrateable-clay minerals
with low-shear-
strength, or a colloidal dispersion of spherical, glacial silt, or synthetic,
inorganic,
spherical particles, both acting as micro-ball-bearing lubricants.
8. The gases to be compressed by these steam-generator and gas-compression
-3-
CA 02745009 2011-06-20
systems may include a multiplicity of components useful in producing a thermal-
energy
carrier fluid (TECF) for the in-situ retorting/refining of fixed-bed,
carbonaceous deposits
(FBCD) such as oil shale, volatile coal beds, tar sands, heavy-oil deposits,
carbonaceous
shale, etc. Such T ECF components may include steam (i.e., H20), air, oxygen-
enriched
air, oxygen, carbon dioxide (C02), carbon monoxide (CO), methane, hydrogen,
etc.
In view of the foregoing, it is a primary objective of the subject invention
to
provide a gas/air-compressor system for compressing air, oxygen, oxygen-
enriched air, or
other gases, for delivering a moderate-to-high-temperature, moderate-to-high-
pressure
fluid (i.e., TECF) for in-situ-retorting and refining of oil shale, volatile
coals, tar sands,
heavy oil and other related hydrocarbon deposits and for a multitude of gas-
compression
applications.
Another object of the invention is to provide a continuous use of a
water/mineral
slurry or emulsion that is a sealant, a lubricant and also a coolant for a
compressor during
the compression cycle.
Still another object of the compressor system is the use of the water/mineral
slurry,
or non-combustible lubricant/water emulsion to create a non-combustible and
non-reactive
compression system for the compression of oxygen-containing fluids.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate complete preferred embodiments in the
present
invention according to the best modes presently devised for the practical
application of the
principles thereof, and in which:
FIG. 1 is a cross-sectional view of the gas/air compressor system, using the
preferred embodiment, with a compressor housing having twin-screw rotors with
gas/air
inlet, water/mineral-slurry or water/lubricant-emulsion injectors and a
gas/air outlet.
FIG. 2 illustrates a pressure/temperature profile of the water-evaporation-
cooled,
compressed gas in the subject compressor system.
FIG. 3 shows a solid-line data of the pressure/temperature profile replotted
on a
log/log plot.
FIG. 4 illustrates a block diagram of an optional final stage of gas/air
compression
using a typical example of a half-mile-long, 2-foot-internal-diameter pipe
cylinder,
providing about 8,300-cubic-foot volume for compression of the gas.
-4-
CA 02745009 2011-06-20
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, the preferred embodiment of the subject gas/air compressor system
is
shown having general reference numeral 10. The compressor system 10 includes a
compressor housing 12 with a male screw rotor 14 meshing with a female screw
rotor 16.
The male screw rotor 14 includes helical lobes 18 received in helical grooves
20 in the
female screw rotor 16.
The compressor system 10 may be designed to provide a high, gas-compression
pressure ratio. In this design, the changing depth of the male helical lobes
18 meshing in
the helical grooves 20, and the changing circumferential length of a cavity 22
between the
adjacent intermeshing rotors with tapered rotor diameters create a
progressively
decreasing cavity volume for gas compression with the rotor's rotation. This
feature
determines the pressure ratios created in the cavity 22.
In this drawing, a gas/air inlet 24 is shown for receiving a gas/air stream,
shown as
arrows 26 inside the housing 12 and compressed in the progressing cavity
created between
the meshing areas of the male and female rotors 14 and 16. A plurality of
spaced-apart,
water or water/mineral injection ports 28 is shown for spraying water or a
water/mineral
slurry, or emulsion, shown, as arrows 30, in the rotating helical grooves 20.
The water or
water/mineral slurry 30 accumulates in a slurry pool 32 just above the meshing
of the male
screw rotor 14 into the female screw rotor 16. The gas/air stream 24 in the
cavity 22 is
progressively compressed in a semi-positive-displacement-like compression. In
this
compressor system 10, the water/mineral slurry or emulsion 30 volume injection
rate,
greater than the evaporation rate, can be used to create a desired volume of
the slurry pool
34 to lubricate and create a partial liquid seal between the male rotor 14 and
female rotor
16 at their points of intermeshing. The resulting compressed, gas/air stream
26 cooling
from the water evaporation will create a pressure/temperature profile
approximately as
illustrated by the lowest dashed line in FIG. 2 or by the area between the two
lower dashed
lines in FIG. 2.
In FIG. 2, a pressure/temperature profile, having general reference numeral
34, of
the compressed gas/air stream 26 in the compressor system 10 is shown wherein
the
water/mineral slurry 30 is sprayed continuously throughout the compression
cycle for
evaporative cooling. A solid middle line 36 represents a curve wherein the
slurry spray
volume rate exactly equals an evaporation volume rate so that no unevaporated
liquid
water remains and no additional water can be evaporated. Two lower dashed
lines 38 and
-5-
CA 02745009 2011-06-20
40 in this drawing represent a condition where excess water is injected and
unevaporated
liquid water is present in the slurry pools 32 just above the point of the
intermeshing
rotors, as shown in FIG. 1. An upper dashed line 42 in this drawing represents
conditions
where insufficient water is injected into the compressor housing 12, resulting
in no
unevaporated water droplets or bulk water existing in the slurry pools 32 in
the
compressor system 10.
In FIG. 3, a solid-line data of FIG. 2 is shown and replotted on a log/log
plot
format. This type of format illustrates a flattened curve, or nearly a
straight line, of the
temperature and pressure shown in FIG. 2 and extended upwardly to pressures of
3,000 psi
and temperatures of 1,200 Rankine, or about 800 Fahrenheit, can be
projected.
To facilitate the lubrication between the male and female screw rotors 14 and
16
and to decrease the rate of water-slurry-sealant leakage between the meshing
surfaces of
the two rotors, a non-combustible, temperature-stable mineral, such as
bentonite clay, or
other hydrateable clay minerals, can be mixed with water to be injected as the
water/mineral slurry 30, as shown in FIG. 1. Such minerals, dispersed in water
and
injected through the injector ports 28, will provide increased liquid
viscosity and increase
the sealant quality thereby decreasing the slurry leakage rate. Also, the low,
mineral-
platelet shear strength of bentonite and similar clay minerals will improve
the lubrication
between the two rotors. Alternatively, a colloidal suspension of an extremely
fine-grained,
nearly spherical grains of glacial silt from glacier outflow, or synthetically
produced,
small, micro-sized spheres (micro-ball-bearings) can be used instead of clay
minerals in
the water/mineral slurry 30 as both a lubricant and sealant. Also, silica gel,
mica, and
other thin mineral platelets in colloidal dispersions, or true solutions, can
be used.
Alternatively, a non-combustible lubricant in a water emulsion may be used.
It should be noted, an adequate amount of excess water must be maintained to
achieve the desired, hydrated-clay-mineral, colloidal-mineral, or lubricant-
emulsion
concentration disbursed in the water for both the desired lubrication and
liquid sealant
qualities. In most applications, the compressed gas/air team 26 will have a
temperature
below 600 F and usually below 500 F, or in some cases can below 400 F, as
shown in
FIG.s 2 and 3. A preferred turbulent flow, instead of laminar flow, can
maintained in the
water/mineral slurry 30 by creating dimples or depressions in the meshing
rotor surfaces to
minimize the leakage volume rate, as illustrated in FIG. 1. This leakage of
water/mineral
slurry 30 flows in a direction from the higher pressure gas/air stream 26 next
to a gas/air
-6-
CA 02745009 2011-06-20
outlet 44 in the cavity in the upper portion of the housing down to the cavity
in a lower
portion of the housing and next to the lower-pressured, gas/air inlet 24.
As a preliminary test, a reservoir of oil-lubricant coolant in an existing,
oil-spray-
lubricated, twin-screw, rotor compressor can be drained, and the oil replaced
with the
water/mineral slurry 30. The slurry 30 must be injected with sufficient volume
into the
compressor housing 12 to have an adequate surplus of water in excess of the
evaporation
rate in order to maintain the slurry pools 32 at the intersections of the male
and female
rotors, as shown in FIG. 1, and thereby prevent dehydration of the clay
minerals in the
slurry and provide an adequate cavity sealant. From these preliminary tests,
using an
existing oil-cooled, twin-screw compressor, operated in a water-injection mode
(i.e.,
without oil), data can be collected to more properly design a desired,
continuous, water-
injected and evaporation-cooled, twin-screw rotor, gas/air compressor system
10.
In the operation of the subject compressor system 10, it can be economically
advantageous to use a first stage, pre-compressor 46, shown in FIG. 4. The pre-
compressor 46 can be a centrifugal turbine compressor or an axial-flow turbine
to
adiabatically compress the gas/air stream 26 from 1 atm up to about 2.5 atm
(i.e., 37.5 psi)
or 6.25 atm. [i.e., (2.5 x 2.5 = 6.25) x 15 = 93.75 psi] as a pre-compression
inlet feed into
the gas/air inlet 24 of the compressor housing 12 in FIG. 1. In this example,
the
compressor system 10 will act as a second-stage and/or a third-stage
compressor to further
compress the gas/air stream 26 up to a desired final pressure.
As an example and referring to the profile curve 36 shown in FIG. 2, the
second-
stage, gas/air-compressor system 10, with a 3.5-times compression ratio, can
compress a
37.5 psi inlet pressure gas up to a 130 psi outlet pressure at about NOT to
350 F. Also, a
93.75 psi, inlet pressure can compress the gas up to a 328 psi outlet pressure
at about
380 F to 430 F. Furthermore, by using the compressor system 10 as a third-
stage
compressor with a 3.5-compression-ratio, the second-stage, 130-psi-pressured
gas can be
compressed in the third stage to 460 psi at about 400 F to 450 F, and the
second-stage,
328-psi-pressured gas can be compressed in the third stage to 1,150 psi at
about 510 F to
560 F.
Obviously, the compressor system 10 can be designed to operate in broader
pressure and temperature ranges. With a 10-times-compression-ratio design, the
gas/air
stream can have a 30 or 50 psi inlet pressure with gas compression up to 300
or 500 psi
outlet pressure, respectively, with a consequent temperature range from 380 to
450
-7-
CA 02745009 2011-06-20
degrees F, as shown in FIG. 2. As another example, when using the pre-
compressor 46 as
a first-stage, 30 to 60-psi compressor and a 5-times-compression-ratio
compressor system
as a second-stage and third-stage compressor, then the second-stage outlet
pressure
would be 150 psi to 300 psi, and the third-stage outlet pressure will be 750
psi to 1,500
psi, respectively, with corresponding temperatures of about 460 F to 560 F
(see FIG. 2).
Other combinations of compressors, with special designed compression ratios,
can
be designed and connected in series to achieve a desired outlet pressure. For
example, if
the pre-compression, inlet pressure to the second-stage compressor system 10
can be
continually varied from 30 psi to 60 psi, this will provide any desired outlet
pressures from
750 psi to 1,500 psi from the second-stage-plus-third-stage compressors of 5-
times-
compression-ratio, each with outlet temperatures ranging from 470 F to 570 F,
respectively, as shown in FIG. 2.
This water-evaporation-cooled gas compressor may be considered as a steam
generator to produce the steam component desired for our thermal-energy
carrier fluid
(TECF). In the process of this injected coolant water being partially
evaporated as it flows
downward through a series of pools of water/mineral slurry accumulated at the
bottom of
each upward-progressing cavity in the twin-screw rotary compressor (see FIG.
1), the
water evaporation process will result in increasing the concentration of
mineral salts
dissolved in this water. If the initially dissolved, mineral-salt
concentration is low enough
and the water injection and outflow rate are high enough, the mineral
concentration in the
partially evaporated water can be kept low enough to prevent precipitation of
any minerals
from this evaporating solution. By maintaining this water at a non-
precipitating,
dissolved-mineral concentration, a non-potable, brackish, produced formation
water can
be used for water injection into this steam-generator/compressor system.
This process requires operating in the temperature/pressure region below the
solid
line in FIG. 2, and probably between the two dashed lines below the solid line
in FIG. 2.
If the injected water rate is too low, resulting in the total evaporation of
all the water, as
illustrated by the dotted line above the solid line in FIG. 2, then mineral
precipitates and
scale will be deposited on the compressor surfaces, unless the water is very
pure, like
distilled water. High-speed, centrifugal-turbine or axial-flow-turbine
compressors cannot
operate in the presence of any liquid droplets, and thereby must operate in
the
temperature/pressure region above the solid line in FIG. 2. Consequently, such
turbine
compressors would require very pure (i.e., distilled) water for total water-
evaporation
-8-
CA 02745009 2011-06-20
coolant. Almost any dissolved mineral in the water would prohibit cooling with
the
turbine compressors, thereby limiting such cooling to interstage cooling
between adiabatic
compression stages.
The ability to use non-potable, brackish, formation water for this continuous,
intra-
stage, partial, water-evaporation cooling provides a major value in the use of
the proposed,
twin-screw rotary compressors, as illustrated in FIG. 1, or the large-volume
cylinder
compressors, as shown in FIG. 4, and in the patent applications to which this
is a
Continuation-In-Part. Furthermore, the water evaporated in this compressor-
coolant
process will eventually be condensed either in the injected formation or in
the production
equipment attached downstream from the producing wells. Consequently, this
condensed
(i.e., distilled) water is a valuable by-product of this process. Also,
concentrated,
dissolved minerals in the water outflow from the compressor may be processed
to extract
selected, precipitated minerals as valuable by-products from this process. Of
particular
interest is the presence of the 1,500 ppm to 3,000-ppm-nahcolite (NaHCO3)
formation
water produced from oil shale which can be concentrated by our compressor's
partial-
evaporation coolant process. When this concentrated nahcolite solution, at
pressures and
temperatures shown by the dashed line in FIG. 2, is depressurized, a nahcolite
precipitate
will be formed which can be used to produce soda ash as a valuable by-product.
Consequently, both mineral precipitates and distilled water can be by-products
of value
which are produced from the partial evaporative cooling of compressor-
injected, non-
potable, brackish, formation water.
The compressor system 10, as shown in FIG. 1, can be operated in reverse as a
twin-screw, rotor-expander to extract shaft horsepower from expanding vapors
produced
from an in-situ, retorting, production well bore, as described in the earlier
filed cited patent
applications, and simultaneously collect the fractionated-condensate liquids
condensed
during the expansion process. In this reverse-cycle expansion process, the
water/mineral
injection ports 28, shown in FIG. 1, can be used as condensate-fractionation
taps to drain
off the condensate liquid fractions as they are produced during the expansion.
In this
expansion-cycle application, the condensed hydrocarbon liquids will form
liquid pools,
similar to slurry pools 32, at the points of the meshing the male and female
rotors 14 and
16 and thereby provide a liquid, gas/vapor sealant and lubricant for the
rotors. Also, using
the subject compressor system 10 as a reverse cycle expansion process, the
system can be
-9-
CA 02745009 2011-06-20
used in large scale electric power plants for generating shaft horsepower from
the
expansion of both the compressor steam and the air combustion products.
In FIG. 4, an optional alternative, final stage or third stage gas/air
compressor
system is shown having general reference numeral 50. This compressor system 50
is
connected to the subject gas/air compressor system 10. The compressor system
50 is
illustrated having a %2-mile (i.e., 2,640-ft) long cylinder 52 or pipeline
with a 24 inch
internal diameter to provide about 8,300-ft3 cylinder volume for compression.
Obviously,
the length of the cylinder 52 can vary in a range of less than a % mile to 1
mile and
greater. The 8,300-ft3 cylinder volume may be pre-charged with 350 psi
compressed air
from the gas/air compressor system 10 of FIG. 1, thereby pushing a water/air
separator
piston 54 to a first end 56 of the cylinder 52. At this point, water, shown as
arrows 58 is
pumped through values 60 and 62 by a combination hydraulic pump/motor 64 or
turbine
and thereby displaces the water/air separator piston 54 (i.e., a modified
pipeline pig) along
the cylinder 52, thereby compressing the air to the injection well-bore
pressure. The valve
60 is connected to a water supply tank 66. The pump/motor 64 is driven by a
large motor
68 with flywheel 70.
The compressed air in the cylinder 52 flows through a valve 72, through a
check
valve 74 and into a pipeline 76 connected to injection wells. The injection
wells are not
shown in the drawings. When the water/air separator piston 54 (i.e., pipeline
pig) reaches
a second end 78 of the '/2-mile-long compression cylinder 52, valves 60 and 62
are
switched to flow water at 350 psi from the compression cylinder 52 through the
hydraulic
pump/motor 64 or turbine to generate shaft horsepower and then flow back into
the water-
supply tank 66. In this operation, valve 72 is connected to the gas/air
compressor system
via an accumulator surge tank 80 and check valve 82. The compressor system 10
is
used to recharge the cylinder 52 at 350 psi in preparation for the next
compression stroke.
The cylinder 52 also includes water injectors 84 for cooling compressed air
exiting the
valve 72 and an exhaust port 86 for discharging exhaust vapors during the
return stroke of
the piston 54. Also shown in this drawing is a surge line 88 with a valve 90
and air/water
surge tank 92 connected to the pipeline 76 and the first end 56 of the
cylinder 52 for
controlling fluid pressure surge during the operation of the optional
compressor system 50
of FIG. 4.
The 350 psi ( 30%) discharge pressure of the compressor system 10, as
discussed
under FIG.s 1-3 can be boosted to a desired well-bore injection pressure by
either (1) the
-10-
CA 02745009 2011-06-20
addition of the pre-compressor 46 designed for this higher pressure, or (2) by
a water-
piston-driven displacement ball (or pipeline pig) in a long pipe (cylinder)
laid on (or
under) sloping ground, as shown in FIG. 4.
If there is an economy of scale for air compressors, then one or more large-
diameter, TECF-compressed-gas/air pipelines may be used to connect all of the
primary
drill sites along a pipeline right-of-way to a small number of compressor
stations. For
example, on each such 1-mile-long pipeline, there could be a single compressor
station
producing 224,000 scfin (i.e., 320 mmscf/d) at 750 psi of compressed, 40% 02,
oxygen-
enriched air, or twice the volume rate of standard 20% oxygen air.
Alternatively,
centralized compressor stations of double this size may be built at 2-mile
intervals along
such pipeline right-of-ways or at any other spacing intervals and
corresponding sizes. The
compressed-gas/air pipeline also serves as a large-volume accumulator to
smooth out any
pressure surges in the line.
Furthermore, these steam-generator/compressor systems, as illustrated in FIG.s
1
and 4 and described herein, may be used as a Continuation-In-Part of the
hydro, internal-
combustion steam engine (ICS cycle), as illustrated in FIG.s 19a, 19b, 20a,
20b and
described on pages 287 to 298 of the Utility Patent Application, titled
"Integrated In-Situ
Retorting and Refining of Oil Shale," as filed on June 19, 2006, Serial No.
11/455,438, by
Gilman A. Hill and Joseph A. Affholter. For large, electric-power-generation
plants, very
large compression cylinders of 8,300 cu ft volume (i.e., %2-mile long x 2-ft
I.D. pipeline) to
66,350 cu ft volume (i.e., 1-mile long x 4-ft I.D. pipeline) may be most
desirable as very
high volume, long-stroke cylinders in a hydro, internal-combustion steam
engine (ICS
cycle). Such large, electric-power plants, using non-potable, brackish water
for partial-
evaporation steam generation, would produce very large volumes of condensed
distilled
water as a high-value byproduct from the power-plant operations.
While the invention has been particularly shown, described and illustrated in
detail
with reference to the preferred embodiments and modifications thereof, it
should be
understood by those skilled in the art that equivalent changes in form and
detail may be
made therein without departing from the scope of the invention as claimed
except as
precluded by the prior art.
-11-
