Title of Invention

A SYSTEM AND A METHOD FOR CLEANING OF A CONTAMINATED COMBUSTION GAS

Abstract The invention relates to an Ultra cleaning of combustion gas to near zero concentration of residual contaminants followed by the capture of CO2 is provided. The high removal efficiency of residual contaminants is accomplished by direct contact cooling and scrubbing of the gas with cold water. The temperature of the combustion gas is reduced to 0-20 degrees Celsius to achieve maximum condensation and gas cleaning effect. The CO2 is captured from the cooled and clean flue gas in a CO2 absorber (134) utilizing an ammoniated solution or slurry in the NH3CO2H2O system. The absorber operates at 0-20 degrees Celsius. Regeneration is accomplished by elevating the pressure and temperature of the CO2 rich solution form the absorber. The CO2 vapor pressure is high and a pressurized CO2 stream, with low concentration of NH3 and water vapor is generated. The high pressure CO2 stream is cooled and washed to recover the ammonia and moisture from the gas.
Full Text PATENT APPLICATION
FOR
ULTRA CLEANING OF COMBUSTION GAS INCLUDING THE
REMOVAL OF CO2
FIELD OF THE INVENTION
The present invention relates to systems and methods for ultra cleaning of combustion gas
followed by the capture and regeneration of CO2.
BACKGROUND
Most of the energy used in the world today is derived from the combustion of carbon and
hydrogen containing fuels such as coal, oil and natural gas. In addition to carbon and
hydrogen, these fuels contain oxygen, moisture and contaminants such as ash, sulfur,
nitrogen compounds, chlorine, mercury and other trace elements. Awareness to the
damaging effects of the contaminants released during combustion triggers the enforcement
of ever more stringent limits on emissions from power plants, refineries and other industrial
processes. There is an increased pressure on operators of such plants to achieve near zero
emission of contaminants and to reduce CO2 emission.
The art teaches various processes and technologies designed to reduce the emission of
contaminants from combustion gases. Baghouses, electrostatic precipitators and wet
scrubbers are typically used to capture particulate matter, various chemical processes are

used to reduce sulfur oxides, HCl and HF emissions, combustion modifications and NOx
reduction processes are used to reduce NOx emission and processes are being developed to
capture mercury and other trace elements from combustion gas.
Significant progress has been made in the last 20-30 years and plants today are a lot cleaner
and safer to the environment than in the past. However, there are growing indications that
even small concentration of particulate matter and especially the very fine, less than 2.5
micron size particles (PM2.5), sulfur oxides, acid mist and mercury are harmful to human
health and need to be controlled.
Controlling the residual emission is still a challenge and with existing technologies the cost
of capturing the last few percents of harmful contaminants is very high.
In addition, in the last few years, there is a growing concern related to the accumulation of
CO2, a greenhouse gas, in the atmosphere. The accelerated increase of CO2 concentration in
the atmosphere is attributed to the growing use of fuels, such as coal, oil and gas, which
release billions of tons of CO2 to the atmosphere every year.
Reduction in CO2 emission can be achieved by improving efficiency of energy utilization,
by switching to lower carbon concentration fuels and by using alternative, CO2 neutral,
energy sources. However, short of a major breakthrough in energy technology, CO2
emitting fuels will continue to be the main source of energy in the foreseeable future.
Consequently, a low cost low energy consuming process for capturing and sequestering
CO2 is needed to reverse the trend of global warming.

State of the art technologies for capturing CO2 are not suitable for operation with dirty, low
pressure, low CO2 concentration, and oxygen containing combustion gases. Available
commercial technologies for CO2 capture are energy intensive and high cost. If applied they
would impose a heavy toll on the cost of energy utilization.
An applicable process currently available for post combustion CO2 capture is the amine
process using Mono-Ethanol-Amine (MEA) or similar amines to react with CO2. The MEA
process is capable of achieving high capture efficiency and of generating a concentrated
CO2 stream for sequestration. However, the process has several drawbacks including:
• The MEA reagent is expensive and degrades in oxygen and CO2 environment.
• The MEA is corrosive and can be used only in a relatively diluted form.
• The reaction of MEA with CO2 is highly exothermic.
• Regeneration is energy intensive.
• The process is a large consumer of heat and auxiliary power.
The cost of the amine process and system is very high and the net power output of a power
plant equipped with amine system to capture CO2 is greatly reduced.
To achieve clean burning of fuels with near zero emission, including the emission of CO2,
there is a need for a low cost low energy process that:
• Captures residual contaminants
• Captures CO2 and releases it in a concentrated and high pressure form for
sequestration.

Accordingly, it would be considered an advance in the art to develop new systems and
methods to overcome the current problems and shortcomings.
SUMMARY OF THE INVENTION
The present invention is an integrated method and system to efficiently and cost effectively
reduce the emission of residuals, such as SO2, SO3, HCl, HF and particulate matter
including PM2.5, from combustion gas, downstream of conventional air pollution control
systems, to near zero levels. Further, the system of the current invention reduces CO2
emission by capturing and delivering it to sequestration in a concentrated form and at high
pressure. It is the objective of this invention that the process would be relatively
uncomplicated, would utilize low cost reagent, would generate no additional waste streams
and most importantly, would be a low cost and low energy consumer.
The present invention is a wet method and system whereby the saturated combustion gas,
downstream of conventional air pollution control equipment and system, is cooled to well
below its ambient saturation temperature. The cooling is achieved by direct contact with
cold water in dedicated vessels. The direct contact between the gas and the liquid,
combining with massive condensation of moisture from the saturated gas, is a very efficient
Wet scrubber. Optionally, alkaline materials such as sodium or ammonium carbonate can be
added to the direct contact cooler to enhance the capture of the acidic species in the gas.
The direct cooling to low temperature can be achieved in one or more cooling stages.
Continuous bleed from the direct contact cooler, prevents the accumulation of the captured
contaminants in the direct contact coolers.

In a preferred embodiment, the chilled water will be generated in cooling towers with
additional cooling, to low temperature in the range of 0-20, or even 0-10, degrees Celsius,
by efficient mechanical vapor compression where the water itself is used as the refrigerant.
In accordance with the, current invention, cooling of the gas substantially reduces its
moisture content. The cooled and low moisture gas has relatively low volume and relatively
high CO2 concentration thus making the efficient capture of CO2 easier and lower cost.
The invention further involves the mass transfer and the reaction of gaseous CO2 from the
combustion gas with CO2-lean ammoniated solution to form CO2-rich ammoniated solution.
According to the current invention, the absorption reaction occurs in a CO2 absorber
operating at about atmospheric pressure and at low temperature preferably in the
temperature range of 0-20, or even 0-10, degrees Celsius. The low temperature enhances
mass transfer of CO2 to the solution while substantially reducing the vapor pressure of
ammonia and preventing its evaporation into the gas stream. One or more stages of CO2
absorption can be used depending on the capture efficiency requirements.
Further, in accordance with the current invention, the pressure of the CO2-rich solution from
the CO2 absorber is elevated by high-pressure pump to the range of 30-2000 psi and it is
heated to the temperature range of 50-200 degrees Celsius and preferably to the temperature
range of 100-150 degrees Celsius. Under the conditions above the CO2 separates from the
solution and evolves as a relatively clean and high-pressure gas stream. The high pressure
CO2 gas stream contains low concentration of ammonia and water vapor, which can be
recovered by cold washing of the CO2 gas steam.

The regeneration reaction is endothermic. However, the heat of reaction is low and the
overall heat consumption of the process is relatively low. Moreover, the high-pressure
regeneration minimizes the evaporation of ammonia and water thus minimizing the energy
consumed in the process. Also, low-grade heat can be used for the regeneration of the CO2
to further reduce the impact of the CO2 capture on the overall efficiency of the plant. The
CO2-lean solution used in the absorber to capture the CO2 contains NH3/CO2 mole ratio in
the range of 1.5-4.0 and preferably in the range of 1.5-3.0. The CO2-rich solution sent for
regeneration contains NH3/CO2 mole ratio in the range of 1.0-2.0 and preferably in the
range of 1.0-1.5.
The present invention has the advantage of high efficiency low cost capture of residual
contaminants from the combustion gas followed by high efficiency low cost capture and
regeneration of CO2. Low temperature absorption and high-pressure regeneration are
critical to successful operation of the process and system. The simple, low cost and efficient
system has notable advantage over other cleaning and CO2 capturing processes and it is a
real breakthrough in achieving the objective of near zero emission of contaminants.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other advantages of this invention will become more apparent from the
following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic representation of the integrated system to capture residual
contaminants and CO2 from combustion gas downstream of conventional air
pollution control systems. The system includes gas cleaning, CO2 absorption
and CO2 regeneration.
FIG. 2 is a schematic of the subsystems for the cooling of the gas and for deep cleaning

of residual contaminants.
FIG. 3 is a schematic of the CO2 capture and regeneration subsystems. It includes CO2
absorber which operates at low temperature and CO2 regenerator which operates
at moderate temperature and at high pressure.

DETAILED DESCRPTION OF THE INVENTION
In accordance with the present invention, a process and system to remove most
contaminants, including CO2, from gas streams is provided. These gases are typically
resulting from the combustion or gasification of coal, liquid fuels, gaseous fuels and organic
waste materials. The contaminants include residual of e.g. SO2, SO3, HCl, HF, CO2,
particulate matter including PM2.5, mercury and other volatile matter. The high removal
efficiency of the contaminants is achieved by saturation and efficient cooling of the gas to
below its adiabatic saturation temperature and preferably to as low as 0-20, or even 0-10,
degrees Celsius. Fine particles and acid mist are nucleation sites for the condensation of
water. Thus, practically all fine particles and acid mist are removed from the gas stream.
The low temperature creates an environment of low vapor pressure of SO2, SO3, HCl, HF,
Mercury and other volatile matter, which condense into the cold water as well.
The cooling of the flue gas enables the efficient capture of CO2 in CO2-lean ammoniated
solution or slurry. Absorption of the CO2 is achieved at low temperature preferably at as
low as 0-20 degrees Celsius or at as low as 0-10 degrees Celsius. The absorbent is
regenerated by elevating the temperature of the solution or slurry to the range of 50-200
degrees Celsius and to pressures in the range of 30-2000 psig. The low temperature of
absorption and the high pressure of regeneration result in high CO2 capture efficiency, low
energy consumption and low loss of ammonia through evaporation.

The CO2 absorption takes place in the aqueous NH3-CO2-H2O system where the ammonia
can be in the form of ammonium ion, NH4+, or in the form of dissolved molecular NH3. The
CO2 can be in the form of carbonate, CO3-, bicarbonate, HCO3- or in the form of dissolved
molecular CO2. The capacity of the solution to absorb CO2 and the form in which the
species are present depends on the ammonia concentration, on the NH3/CO2 mole ratio and
on the temperature and pressure.
High NH3/CO2 mole ratio increases the vapor pressure of ammonia and results in ammonia
losses through evaporation. Low NH3/CO2 ratio increases the vapor pressure of CO2 and
decreases its capture efficiency. Thus, the optimal NH3/CO2 mole ratio for absorption is in
the range of 1.0-4.0 and preferably in the range of 1.5 to 3.0. High temperature increases
the vapor pressure of both ammonia and CO2. As a result, the absorber should operate at the
lowest practical temperature and preferably in the 0-20 degrees Celsius temperature range
or even in the 0-10 degrees Celsius temperature range.
At high concentration and lower temperature the solubility limits may be reached and solids
particles precipitate. These solids particles are typically in the form of ammonium carbonate
(NH4)2CO3 for high NH3/CO2 ratio and ammonium bicarbonate NH4HCO3 for low
NH3/CO2 ratio.
The mass transfer and absorption reactions for concentrated low temperature slurries are the
following:



Where CO2 captured from the gas converts ammonium carbonate to ammonium
bicarbonate. The reactions above are reversible and CO2 is stripped from the liquid phase at
elevated temperature.
Depending on the operating conditions, side undesired reactions may occur such as:

Causing emission of NH3 into the gas phase. Lower temperature and lower NH3/CO2 ratio
in the absorber suppresses these undesired reactions. However, during the regeneration and
at elevated temperature, gaseous ammonia is formed. To prevent ammonia from escaping
from the liquid phase (and for other reasons) the regenerator is deigned to operate under
elevated pressure and under conditions where the solubility of ammonia in the solution is
very high and the emission of gaseous ammonia is very low.
FIG. 1 is a schematic representation of the integrated process, which includes cleaning and
cooling of the gas, CO2 absorption into CO2-lean ammoniated solution and CO2
regeneration from the CO2-rich solution. Stream 102 is a gas stream from combustion or
industrial process containing residual contaminants, CO2 and inert gas species. The CO2
concentration of the gas is typically 10-15% for coal combustion and 3-4% for natural gas
combustion. Subsystem 130 represents a series of conventional air pollution control

processes which, depending on the source of the gas may include particulate collectors, NOx
and SO2 control, acid mist capturing device and more. The contaminants collected in the
system are removed in stream 112. Stream 104, downstream of the conventional cleaning
devices, contains residual contaminants not collected by the conventional systems. It is
typically water saturated and in the temperature range of 40-70 degrees Celsius. Subsystem
132 is a series of one or more Direct Contact Coolers (DCC), where cold water generated in
cooling towers and chillers (not shown) is used to wash and scrub the gas, capture its
residual contaminants and lower its moisture content. Stream 114, is a bleed from
subsystem 132 designed to purge all the residual contaminants captured.
Stream 106 is a cooled gas suitable for CO2 capture in the CO2 absorber. Subsystem 134
represents the CO2 absorber and may comprise of a series of absorber stages, depending on
the removal efficiency required and the operating conditions of the plant. The clean gas
with low CO2 concentration, stream 108, is released to the atmosphere. Stream 124 is a
cooled CO2-lean ammoniated solution from the regenerator, subsystem 136, which is used
as the absorbent to capture the CO2 in the absorber. The resultant stream 120 is a CO2-rich
ammoniated solution sent for regeneration.
The regenerator, subsystem 136, operates at high pressure and elevated temperature and
may be a single or a series of regeneration reactors. The pressure of the ammoniated
solution fed to the regenerator is elevated using high pressure pump, pump 138, to yield
stream 122 which is CO2-rich and at high pressure. Typically, the pressure of stream 122 is
in the range of 50-2500 psi, higher than the regenerator pressure to prevent premature
evaporation of CO2. Heat is provided to the regenerator by heating stream 126 in heater
140. The high pressure and high temperature in the regenerator cause the release of high-

pressure gaseous CO2, stream 110. The high-pressure regeneration has major cost and
energy advantage. Low quality thermal energy is used to generate the high pressure CO2
stream instead of high-value electric power.
FIG. 2 is a schematic representation of the cooling and cleaning subsystems, which may
optionally include waste heat recovery, heat exchanger 240, for utilization of the residual
heat in the gas. The residual heat in stream 202 can be extracted in heat exchanger 240 by
transferring of the heat to a cooling medium streams 220 and 222. The heat can then be
used downstream for CO2 regeneration.
Vessel 242 is a wet direct contact scrubber used to adiabatically cool and saturate the gas. If
the gas contains high concentration of acid species, such as gas from coal or oil fired power
plants, then reactor 242 is used for flue gas desulfurization. Acid absorbing reagent, such as
limestone, stream 226, is added to vessel 242 and the product, such as gypsum, stream 224,
is withdrawn. Make up water, stream 227, is added to vessel 242 from the Direct Contact
Cooler (DCC) 244. The make up stream contains all the contaminants collected in the direct
contact coolers. These contaminants are removed from the system with the discharge stream
224. Gas stream 202 in coal fired boiler is typically at temperature in the range of 100-200
degrees Celsius, gas stream 204 is typically at temperature range of 80-100 degrees Celsius
and gas stream 206 is typically water-saturated and at temperature range of 40-70 degrees
Celsius.
Two stages of direct contact cooling and cleaning, vessels 244 and 246, are shown in FIG.
2. The actual number of direct contact coolers may be higher and it depends on optimization
between capital cost, energy efficiency and cleaning efficiency requirements.

Gas stream 206 is cooled in DCC 244 to just above the cooling water temperature of stream
230. The temperature of the cooling water, stream 230, depends on the ambient conditions
and on the operation and process conditions of Cooling Tower 250. Cooling Tower 250 can
be of the wet type with temperature slightly below or slightly above ambient temperature, or
the dry type with temperature above ambient temperature. Ambient air, Stream 212
provides the heat sink for the system and the heat is rejected in Stream 214, which absorbs
the heat from water stream 228. The resultant cooled water stream 230, is typically at
temperature range of 25-40 degrees Celsius and the resultant cooled combustion gas stream
from DCC 244 is at about 1-3 degrees Celsius higher temperature. Alkaline materials such
as ammonium or sodium carbonate can be added to DCC 244 to neutralize the acidic
species captured. The alkaline materials can be added in makeup water, stream 225.
The cleaner and lower temperature, Stream 208 flows to DCC 246, which is similar to DCC
244 except for the fact that colder water, stream 234, is used for cooling. Stream 234 is a
chilled water stream cooled by Chiller 248, which is preferably a mechanical vapor
compression machine with water as its refrigerant. Heat from Chiller 248 is rejected via
stream 236 to Cooling Tower 250 with returning stream 238. Cooling water stream 234 can
be as cold as 0-3 degrees Celsius or higher resulting in combustion gas temperature, stream
210, exiting DCC 246 being at 0-10 degrees Celsius temperature or few degrees higher. The
heat absorbed from the gas stream is removed from DCC 246 via water stream 232. More
condensation occurs in DCC 246 and further capture of contaminants. These contaminants
are bled from the system to vessel 242. (Bleed stream is not shown).

Gas Stream 210, the product of the cooling and cleaning subsystem shown in FIG. 2, is at
low temperature; it contains low moisture and practically has no particulate matter, acidic or
volatile species.
FIG. 3 is a schematic representation of the CO2 capture and regeneration subsystem. Stream
302 is a clean and cooled gas stream, similar to stream 210 in FIG. 2. It flows into the CO2
absorber 350, where the CO2 is absorbed by a cooled CO2-lean ammoniated solution or
slurry, Stream 324 containing NH3/CO2 mole ratio in the range of 1.5-4.0 and preferably
1.5-3.0. Depending on the absorber design and the number of absorption stages used, more
than 90% of the CO2 in Stream 302 can be captured to yield a cold and CO2 depleted gas
stream 304. Residual ammonia in stream 304 can be washed in vessel 356 by cold water or
by cold and slightly acidic solution, stream 338. Stream 338 is cooled in heat exchanger
368. As a result of the cooling, cleaning and CO2 capture, the gas stream discharged from
the system, Stream 306, contains mainly nitrogen, oxygen and low concentration of CO2
and H2O.
Stream 324 is a CO2-lean stream from the regenerator, which is cooled in the regenerative
heat exchanger 354 and further by chilled water in heat exchanger 362. It captures CO2 in
absorber 350 and discharges from the absorber, Stream 312, as a CO2-rich stream with
NH3/CO2 mole ratio in the range of 1.0-2.0 and preferably with NH3/CO2 mole ratio in the
range of 1.0-1.5. In a preferred embodiment, stream 312 contains high concentration of
dissolved and suspended ammonium bicarbonate. A portion of stream 312 is optionally
recycled back to the absorber while the balance, Stream 314, is pressurized in high pressure
pump 360 to yield high pressure ammoniated solution stream 316. Stream 316 is heated in
regenerative heat exchanger 354, by exchanging heat with the hot and CO2-lean stream

from the regenerator, stream 322, which is a portion of stream 320 discharged at the bottom
of regenerator 352.
The CO2-rich stream from the regenerative heat exchanger 354, stream 318, can be further
heated with waste heat from the boiler or from other sources. It flows into the regenerator
352, which has one or more stages of regeneration. More heat is provided to the
regenerator from heat exchanger 364, which heats stream 330. The heat provided to the
system from the various sources, elevates the regenerator temperature to 50-150 degrees
Celsius or higher, depending on the desired pressure of the CO2 stream 308 and subject to
cost optimization consideration. The higher the temperature the higher will be the pressure
of the CO2 that evolves from the solution, stream 308. The higher the pressure the lower
will be the ammonia and water vapor content of stream 308. To generate low temperature
and highly concentrated CO2 stream, stream 308 is washed and cooled in direct contact
vessel 358 with cold water, stream 336 from heat exchanger 366. Excess water and NH3
captured in vessel 358, stream 332, flows back to regenerator 352 while the balance, stream
334, is cooled and recycled to the wash chamber, vessel 358.
The present invention has now been described in accordance with several exemplary
embodiments, which are intended to be illustrative in all aspects, rather than restrictive.
Thus, the present invention is capable of many variations in detailed implementation, which
may be derived from the description contained herein by a person of ordinary skill in the
art. All such variations and other variations are considered to be within the scope and spirit
of the present invention as defined by the following claims and their legal equivalents.

WE CLAIMS
1. A system for cleaning of a contaminated combustion gas, comprising:
a) one or more direct and wet cooling stages configured to cool a gas
stream to condense water from said gas stream and to capture and
remove contaminants from said gas stream, wherein the one or more
direct and wet cooling stages includes a final cooling stage configured
to cool the gas stream to below ambient temperature;
b) one or more CO2 absorbing stages configured to absorb CO2 from the
gas stream cooled to below ambient temperature using an
ammoniated solution or slurry;
c) a pressurizer configured to pressurize the ammoniated solution or
slurry with the absorbed CO2; and
d) one or more CO2 regeneration stages configured to separate absorbed
CO2 from said pressurized ammoniated solution or slurry.

2. The system as claimed in claim 1, wherein said final cooling stage is
configured to cool said gas stream to 0-20 degrees Celsius.
3. The system as claimed in claim 1, wherein said final cooling stage is
configured to cool said gas stream to 0-10 degrees Celsius.

4. The system as claimed in claim 1, wherein the one or more CO2absorbing
stages are configured to absorb said CO2 using a CO2-lean NH3—CO2—H2O
solution or slurry.
5. The system as claimed in claim 4, wherein said CO2-Iean solution or slurry
has a NH3/CO2 mole ratio in the range of 1.5-4.0.
6. The system as claimed in claim 4, wherein said CO2-Iean solution or slurry
has a NH3/CO2 mole ratio in the range of 1.5-3.0.
7. The system as claimed in claim 1, wherein said one or more CO2
absorbing stages are configured to operate at a temperature in the range
of 0-20 degrees Celsius.
8. The system as claimed in claim 1, wherein said one or more CO2
absorbing stages are configured to operate at a temperature in the range
of 0-10 degrees Celsius.
9. The system as claimed in claim 1, wherein said one or more CO2
absorbing stages are configured to absorb CO2 so as to generate a CO2-
rich NH3—CO2—H2O solution.
10.The system as claimed in claim 9, wherein said CO2-rich solution has a
NH3/CO2 mole ratio in the range of 1.0-2.0.
11.The system as claimed in claim 9, wherein said CO2-rich solution has a
NH3/CO2 mole ratio in the range of 1.0-1.5.

12.The system as claimed in claim 1, comprising:
a heater configured to heat the ammoniated solution or slurry with the
absorbed CO2 to a temperature in the range of 50-200 degrees Celsius;
wherein the one or more CO2 regeneration stages are configured to
separate absorbed CO2 from said pressurized and heated ammoniated
solution or slurry.
13.The system as claimed in claim 1, comprising:
a heater configured to heat the ammoniated solution or slurry with the
absorbed CO2 to a temperature in the range of 100-150degrees Celsius;
wherein the one or more CO2 regeneration stages are configured to
separate absorbed CO2 from said pressurized and heated ammoniated
solution or slurry.
14.The system as claimed in claim 1, wherein said pressurizer is configured
to pressurize the ammoniated solution or slurry to a pressure in the range
of 30-2000 psi.
15.The system as claimed in claim 1, wherein said pressurizer is configured
to pressurize the ammoniated solution or slurry to a pressure in the range
of 150-400 psi.
16. A method for cleaning of a contaminated combustion gas, comprising:

a) cooling down a gas stream to condense water from said gas stream
and to capture and remove contaminants from said gas stream,
wherein the gas stream is cooled to below ambient temperature;
b) absorbing CO2 from said cooled gas stream using an ammoniated
solution or slurry, wherein the cooled gas stream and ammoniated
solution or slurry are maintained below ambient temperature during
said absorbing;
c) pressurizing the ammoniated solution or slurry with the absorbed CO2;
and
d) regenerating CO2 by separating CO2 from said pressurized ammoniated
solution or slurry.
17.The method as claimed in claim 16, wherein said gas stream is cooled to a
temperature in the range of 0-20 degrees Celsius.
18.The method as claimed in claim 16, wherein said gas stream is cooled to a
temperature in the range of 0-10 degrees Celsius.
19.The method as claimed in claim 16, wherein the ammoniated solution or
slurry used to absorb said CO2 is a CO2 lean NH3—CO2—H2O solution or
slurry.
20.The method as claimed in claim 19, wherein said CO2-lean solution or
slurry has a NH3/CO2 mole ratio in the range of 1.5-4.0.

21.The method as claimed in claim 19, wherein said CO2-lean solution or
slurry has a NH3/CO2 mole ratio in the range of 1.5-3.0.
22.The method as claimed in claim 19, wherein said NH3—CO2—H2O solution
or slurry is in water-dissolved form.
23.The method as claimed in claim 19, wherein the species in said NH3—
CO2—H2O solution or slurry are concentrated such to contain dissolved
and suspended solids having ammonium carbonate, (NH4) 2CO3, and
ammonium bjcarbonate, NH4HCO3, salts.
24.The method as claimed in claim 16, wherein the cooled gas stream and
ammoniated solution or slurry maintained at a temperature in the range of
0-20 degrees Celsius during said absorbing.
25.The method as claimed in claim 16, wherein the cooled gas stream and
ammoniated or slurry are maintained at a temperature in the range of 0-
10 degrees Celsius during said absorbing.
26.The method as claimed in claim 16, wherein said ammoniated solution or
slurry with the absorbed CO2 is a CO2-rich NH3—CO2—H2O solution.
27.The method as claimed in claim 26, wherein said CO2-rich solution has a
NH3/CO2 mole ratio in the range of 1.0-2.0.
28.The method as claimed in claim 26, wherein said CO2-rich solution has a
NH3/CO2 mole ratio in the range of 1.0-1.5.

29.The method as claimed in claim 16, comprising:
heating the ammoniated solution or slurry with the absorbed CO2 to a
temperature in the range of 50-200 degrees Celsius;
wherein the pressurized ammoniated solution or slurry from which CO2 is
separated to regenerate CO2 is the pressurized and heated ammoniated
solution or slurry.
30.The method as claimed in claim 16, comprising:
heating the pressurized ammoniated solution or slurry with the absorbed
CO2 to a temperature in the range of 100-150 degrees Celsius;
wherein the pressurized ammoniated solution or slurry from which CO2 is
separated to regenerate CO2 is the pressurized and heated ammoniated
solution or slurry.
31.The method as claimed in claim 16, wherein the ammoniated solution or
slurry with the absorbed CO2 is pressurized to a pressure in the range of
30-2000 psi.
32.The method as claimed in claim 16, wherein the ammoniated solution or
slurry with the absorbed CO2 is pressurized to a pressure in the range of
150-400 psi.


The invention relates to an Ultra cleaning of combustion gas to near zero
concentration of residual contaminants followed by the capture of CO2 is
provided. The high removal efficiency of residual contaminants is accomplished
by direct contact cooling and scrubbing of the gas with cold water. The
temperature of the combustion gas is reduced to 0-20 degrees Celsius to achieve
maximum condensation and gas cleaning effect. The CO2 is captured from the
cooled and clean flue gas in a CO2 absorber (134) utilizing an ammoniated
solution or slurry in the NH3CO2H2O system. The absorber operates at 0-20
degrees Celsius. Regeneration is accomplished by elevating the pressure and
temperature of the CO2 rich solution form the absorber. The CO2 vapor pressure
is high and a pressurized CO2 stream, with low concentration of NH3 and water
vapor is generated. The high pressure CO2 stream is cooled and washed to
recover the ammonia and moisture from the gas.

Documents:

00221-kolnp-2007-assignment.pdf

00221-kolnp-2007-correspondence-1.1.pdf

00221-kolnp-2007-correspondence-1.2.pdf

00221-kolnp-2007-others document.pdf

0221-kolnp-2007-abstract.pdf

0221-kolnp-2007-claims.pdf

0221-kolnp-2007-correspondence others.pdf

0221-kolnp-2007-description (complete).pdf

0221-kolnp-2007-drawings.pdf

0221-kolnp-2007-form1.pdf

0221-kolnp-2007-form2.pdf

0221-kolnp-2007-form3.pdf

0221-kolnp-2007-form5.pdf

0221-kolnp-2007-international publication.pdf

0221-kolnp-2007-international search authority report.pdf

0221-kolnp-2007-pct form.pdf

221-KOLNP-2007-(26-03-2012)-CERTIFIED COPIES(OTHER COUNTRIES).pdf

221-KOLNP-2007-(26-03-2012)-CORRESPONDENCE.pdf

221-KOLNP-2007-(26-03-2012)-FORM-13.pdf

221-KOLNP-2007-(26-03-2012)-PA-CERTIFIED COPIES.pdf

221-KOLNP-2007-ABSTRACT 1.1.pdf

221-KOLNP-2007-ABSTRACT.pdf

221-KOLNP-2007-ASSIGNMENT-1.1.pdf

221-kolnp-2007-assignment.pdf

221-KOLNP-2007-CLAIMS 1.1.pdf

221-KOLNP-2007-CLAIMS.pdf

221-KOLNP-2007-CORRESPONDENCE 1.1.pdf

221-KOLNP-2007-CORRESPONDENCE-1.2.pdf

221-kolnp-2007-correspondence.pdf

221-KOLNP-2007-DESCRIPTION (COMPLETE) 1.1.pdf

221-KOLNP-2007-DESCRIPTION (COMPLETE).pdf

221-KOLNP-2007-DRAWINGS.pdf

221-KOLNP-2007-EXAMINATION REPORT REPLY RECIEVED.pdf

221-kolnp-2007-examination report.pdf

221-KOLNP-2007-FORM 1.pdf

221-KOLNP-2007-FORM 16.pdf

221-kolnp-2007-form 18-1.1.pdf

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221-KOLNP-2007-FORM 2 1.1.pdf

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221-kolnp-2007-form 26-1.1.pdf

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221-KOLNP-2007-FORM-27.pdf

221-kolnp-2007-granted-abstract.pdf

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221-KOLNP-2007-PA.pdf

221-KOLNP-2007-PETITION UNDER RULE 137.pdf

221-kolnp-2007-reply to examination report.pdf

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Patent Number 248224
Indian Patent Application Number 221/KOLNP/2007
PG Journal Number 26/2011
Publication Date 01-Jul-2011
Grant Date 28-Jun-2011
Date of Filing 18-Jan-2007
Name of Patentee EIG, INC
Applicant Address 10245 PARKWOOD DRIVE #8 CUPERTINO, CA 95014
Inventors:
# Inventor's Name Inventor's Address
1 GAL, ELI 10245 PARKWOOD DRIVE #8 CUPERTINO, CA 95014
PCT International Classification Number B01D53/14
PCT International Application Number PCT/US2005/012794
PCT International Filing date 2005-04-12
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/617,779 2004-10-13 U.S.A.
2 60/599,228 2004-08-06 U.S.A.