PCT
`
`WORLD INTELLECTUAL PROPERTY ORGANIZATION
`International Bureau
`
`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`
`(51) International Patent Classification 6 :
`B01D 53/62, 53184, C12M 1/40
`
`A1
`
`(11) International Publication Number:
`
`WO 98155210
`
`(43) International Publication Date: 10 December 1998 (10.12.98)
`
`(21) International Application Number:
`
`PCT/CA98/00541
`
`(22) International Filing Date:
`
`2 June 1998 (02.06.98)
`
`(30) Priority Data:
`9711439.1
`
`4 June 1997 (04.06.97)
`
`GB
`
`(71) Applicant (for all designated States except US): SYSTEMES
`ENVIROBIO INC. [CA/CA]; 825, rue Commerciale,
`Saint-Jean-Chrysostome, Qu6bec G6Z 1El (CA).
`
`(81) Designated States: AL, AM, AT, AU, AZ, BA, BB, BG, BR,
`BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GE,
`GH, GM, GW, HU, ID, IL, IS, JP, KE, KG, K.P, KR, KZ,
`LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, !vlW,
`MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL,
`TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZW, ARIPO
`patent (GH, GM, KE, LS, MW, SD, SZ, UG, ZW), Eurasian
`patent (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), European
`patent (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR,
`IE, IT, LU, MC, NL, PT, SE), OAPI patent (BF, B J, CF,
`CG, CI, CM, GA, GN, ML, MR, NE, SN, TD, TG).
`
`(72) Inventors; and
`(75) Inventors/Applicants (for US only): BLAIS, R6jean [CA/CA];
`5915, Saint-Laurent, L6vis, Qu6bec G6V 3V6 (CA).
`ROGERS, Peter, A. [CA/CA]; 1091, boulevard Pie XI Sud,
`Val-B61air, Qu6bec G3X 1J9 (CA).
`
`Published
`With international search report.
`Before the expiration of the time limit for amending the
`claims and to be republished in the event of the receipt of
`amendments.
`
`(74) Agent: ROBIC; 55, Saint-Jacques, Montr6al, Qu6bec H2Y 3X2
`(CA).
`
`(54) Title: PROCESS AND APPARATUS FOR THE TREATMENT OF CARBON DIOXIDE WITH CARBONIC ANHYDRASE
`
`(57) Abstract
`
`A process is disclosed for the extraction, production and purification of
`carbon dioxide gas. The process may also be employed for the production
`of aqueous and/or organic solutions of bicarbonate ions using a precursor
`feed stream of gas containing carbon dioxide. The process consists of the
`countercurrent flushing of a packed tower-type bioreactor with gas containing
`carbon dioxide and a liquid solvent. The bioreactor contains carbonic anhydrase
`covalently bound to an inert inorganic support. The carbon dioxide of the gaseous
`phase diffuses into the liquid phase. The immobilized carbonic anhydmse
`catalyses the hydration of the carbon dioxide which forms hydrogen and
`bicarbonate ions. The solution of ions may be employed directly or, alternatively,
`subjected to an ion-exchange resin to immobilize the bicarbonate ions. The
`aqueous solution of hydrogen and bicarbonate ions may also be recirculated into
`a second identical bioreactor, wherein they are catalytically converted to water
`and carbon dioxide.
`
`Akermin, Inc.
`Exhibit 1014
`Page 1
`
`

`

`FOR THE PURPOSES OF INFORMATION ONLY
`
`Codes used to identify States party to the PCT on the front pages of pamphlets publishing international applications under the PCT.
`
`AL
`
`AM
`
`AT
`
`AU
`AZ
`
`BA
`
`BB
`
`BE
`
`BF
`
`BG
`
`BJ
`BR
`
`BY
`
`CA
`
`CF
`
`CG
`CH
`
`CI
`
`CM
`
`CN
`
`CU
`CZ
`
`DE
`
`DK
`EE
`
`Albania
`Armenia
`Austria
`Australia
`Azerbaijan
`Bosnia and Herzegovina
`Barbados
`Belgium
`Burkina Faso
`Bulgaria
`Benin
`Brazil
`Belaras
`Canada
`Central African Republic
`Congo
`Switzerland
`Cfte d’Ivoire
`Cameroon
`China
`Cuba
`Czech Republic
`Germany
`Denmark
`Estonia
`
`ES
`FI
`FR
`GA
`GB
`GE
`GH
`GN
`GR
`HU
`IE
`IL
`IS
`IT
`JP
`KE
`KG
`KP
`
`KR
`KZ
`LC
`LI
`LK
`LR
`
`Spain
`Finland
`France
`Gabon
`United Kingdom
`Georgia
`Ghana
`Guinea
`Greece
`Hungary
`Ireland
`Israel
`Iceland
`Italy
`Japan
`Kenya
`Kyrgyzstan
`Democratic People’s
`Republic of Korea
`Republic of Korea
`Kazakstan
`Saint Lucia
`Liechtenstein
`Srl Lanka
`Liberia
`
`LS
`LT
`LU
`LV
`MC
`MD
`MG
`MK
`
`ML
`MN
`MR
`MW
`MX
`NI~,
`NL
`NO
`NZ
`PL
`PT
`RO
`RU
`SD
`SE
`SG
`
`Lesotho
`Lithuania
`Luxembourg
`Latvia
`Monaco
`Republic of Moldova
`Madagascar
`The former Yugoslav
`Republic of Macedoaia
`Mali
`Mongolia
`Mauritania
`Malawi
`Mexico
`Niger
`Netherlands
`Norway
`New Zealand
`Poland
`Portugal
`Romania
`Russian Federation
`Sudan
`Sweden
`Singapore
`
`SI
`SK
`SN
`SZ
`TD
`TG
`TJ
`TM
`TR
`TT
`UA
`UG
`US
`UZ
`VN
`YU
`ZW
`
`Slovania
`Slovakia
`Senegal
`Swaziland
`Chad
`Togo
`Tajikistan
`Turkmenistan
`Turkey
`Trinidad and Tobago
`Ukraine
`Uganda
`United States of America
`Uzbekistan
`Viet Nam
`Yugoslavia
`Zimbabwe
`
`Akermin, Inc.
`Exhibit 1014
`Page 2
`
`

`

`WO 98/55210
`
`PCT/CA98/00541
`
`PROCESS AND APPARATUS FOR THE TREATMENT OF CARBON DIOXIDE WITH CARBONIC ANHYDRASE
`
`1
`
`FIELD OF THE INVENTION
`
`The present invention relates generally to a process for the extraction,
`
`production and purification of carbon dioxide gas. More particularly, it relates to the
`
`use of a biological molecule, namely carbonic anhydrase, to effect the reversible
`
`10
`
`hydration of carbon dioxide. Carbonic anhydrase can be used for the production,
`
`purification of carbon dioxide and the products of the hydration reaction, hydrogen
`
`and bicarbonate ions. Specifically, the invention relates to a process whereby
`
`immobilized carbonic anhydrase contained within a reactor device catalyses the
`
`reversible hydration of carbon dioxide. The invention also relates to an apparatus for
`
`15
`
`performing the process. The process may be employed for the production of
`
`hydrogen and bicarbonate ions.
`
`BACKGROUND OF THE INVENTION
`
`2O
`
`Carbonic anhydrase (EC 4.2.1.1.) is a globular zinc metalloenzyme of
`
`molecular mass 30,000. The enzyme was discovered in 1933 and has been the
`
`subject of intense scientific investigation. Multiple isoforms have been discovered in
`
`plant and animal tissues. The enzyme also exists in plant tissues where it is believed
`
`to facilitate the transport of carbon dioxide. Red blood cells contain isoenzymes I and
`
`25
`
`II, which are the most active. Carbonic anhydrase II has the highest molecular
`
`turnover number of any known enzyme. One molecule of carbonic anhydrase can
`
`hydrate 36,000,000 molecules of carbon dioxide in a period of 60 seconds.
`
`Physiologically, carbonic anhydrase facilitates the removal of carbon dioxide from
`
`the mammalian body. The general enzyme reaction is shown below in equation 1.
`
`3O
`
`Akermin, Inc.
`Exhibit 1014
`Page 3
`
`

`

`WO 98/55210
`
`PCT/CA98/00541
`
`Equation 1:
`
`2
`
`C02
`+ H20 ~ H÷ + HCO3-
`
`It is now generally accepted that the reaction occurs as two half reactions
`
`5
`
`shown below in equations 2 and 3.
`
`10
`
`15
`
`Equation 2:
`
`Equation 3:
`
`E- Zn- H20 ~ E- Zn- OH- + H÷
`
`E - Zn - OH + CO2 ,=, E - Zn - HCO~ + H÷ = (+H=O,-HzO) = E - H~O + HCO3
`
`Carbonic anhydrase has been used in many studies directed at improving or
`
`testing of various methods of protein immobilization. The high molecular turnover
`
`rate of the enzyme renders it an ideal protein for these types of experiments.
`
`The presence of carbonic anhydrase in solution facilitates the transfer of
`
`carbon dioxide from the gas to the liquid phase. This effect is based on the well
`
`20
`
`established laws governing the mass transfer of gases.
`
`The management of carbon dioxide has begun to attract the attention of the
`
`scientific community, due primarily to the problem of global warming. Previous
`
`interest in carbon dioxide has been centered around the use of the gas in a variety
`
`of industrial processes. None of the currently employed carbon dioxide management
`
`25
`
`systems involve enzymatic conversion of the gas and are therefore not relevant to
`
`the present application. Prior art processes for the management of carbon dioxide
`
`are described in the following US documents: 3,659,400; 3,853,712; 4,032,616;
`
`4,047,894; 4,162,298; 4,452,676; 4,521,387; 4,710,362; 5,061,455; 5,112,740;
`
`5,609,838; 5,618,506; 5,624,812; 5,665,319; 5,674,463; and 5,690,099.
`
`30
`
`Moreover, the United States Air Force carried out two investigations in 1965
`
`and 1966 on the possible use of carbonic anhydrase to remove carbon dioxide from
`
`Akermin, Inc.
`Exhibit 1014
`Page 4
`
`

`

`WO 98/55210
`
`PCT/CA98/00541
`
`3
`
`space vehicles. The first study explored the absorption of carbon dioxide from an air
`
`stream using a closed air loop apparatus. A variety of chemicals alone and/or in
`
`combination with CA were evaluated, with respect to their capacity to remove carbon
`
`dioxide: The principal conclusion drawn was that the closed air loop system provided
`
`5
`
`an adequate method to study the removal of carbon dioxide from a stream of air. The
`
`second study was directed at determining the efficiency of carbon dioxide removal
`
`from an air stream using carbonic anhydrase in the presence of various amines. The
`
`conclusion reached was that enzymatic amine solutions could possibly be used for
`
`carbon dioxide absorption and desorption in atmosphere control concepts.
`
`10
`
`Although many studies relating to the management of carbon dioxide have
`
`been conducted in prior art, there is still presently a need for a process and an
`
`apparatus that will efficaciously manage carbon dioxide rapidly and at a relatively low
`
`cost either for producing carbon dioxide or removing it from a CO2-containing gas.
`
`15
`
`SUMMARY OF THE INVENTION
`
`An object of the present invention is to propose a process and an apparatus
`
`that will satisfy these needs.
`
`In accordance with the present invention, that object is achieved with a
`
`20
`
`process for removing CO2 from a CO-2containing gas, characterized in that it
`
`comprises the step of:
`
`a) contacting the CO2-containing gas with an aqueous liquid, preferably water,
`
`in a bioreactor containing immobilized carbonic anhydrase, or an analog thereof, the
`
`carbonic anhydrase catalysing the hydration of the CO2 into hydrogen ions and
`
`25
`
`bicarbonate ions.
`
`Preferably, prior to step a), there is a step of immobilizing carbonic anhydrase
`
`in the bioreactor. The step of immobilizing carbonic anhydrase in the bioreactor may
`
`comprise the step of covalently binding carbonic anhydrase to an inert solid support
`
`material mounted in the bioreactor. The step a) of contacting the CO2-containing gas
`
`30
`
`with an aqueous liquid comprises the steps of directing a stream of the CO~-
`
`containing gas upwards into the bioreactor and directing a stream of the aqueous
`
`Akermin, Inc.
`Exhibit 1014
`Page 5
`
`

`

`WO 98/55210
`
`PCT/CA98/00541
`
`4
`
`liquid downwards such that the stream of CO2-containing gas flows countercurrent
`
`the stream of the aqueous solution.
`
`According to a first preferred embodiment of the present invention, the
`
`process comprises, after step a), step b) of feeding the hydrogen ions and
`
`5
`
`bicarbonate ions obtained in step a) into a second bioreactor containing immobilized
`
`carbonic anhydrase which catalyses the conversion of the hydrogen ions and the
`
`bicarbonate ions into concentrated CO2 and water.
`
`According to a second preferred embodiment of the invention, the process
`
`comprises, after step a), the step of feeding the hydrogen ions and bicarbonate ions
`
`10
`
`obtained in step a) into an ion exchanger containing hydroxyl ions so that the
`
`carbonate ions are exchanged for the hydroxyl ions which are then free to combine
`
`with hydrogen ions to form water.
`
`The present invention also relates to an apparatus for the management of CO~
`
`using immobilized carbonic anhydrase or analog thereof. The apparatus comprises
`
`15
`
`an upright bioreactor for growing carbonic anhydrase therein.
`
`The bioreactor comprises a bottom chamber having a gas inlet to receive a
`
`CO2-containing gas and a liquid outlet to evacuate from the bioreactor a liquid
`
`solution containing hydrogen ions and bicarbonate ions produced in the bioreactor.
`
`The bioreactor further comprises an upper chamber having a liquid inlet to receive
`
`2O
`
`an aqueous liquid and a gas outlet to evacuate any gas from the bioreactor.
`
`A reaction chamber is disposed between and is in fluid communication with
`
`the bottom chamber and the upper chamber. This reaction chamber is characterized
`
`in that it comprises a plurality of inert organic supports mounted therein for covalently
`
`immobilizing carbonic anhydrase.
`
`25
`
`In use, the CO2-containing gas is fed through the gas inlet and an aqueous
`
`liquid, preferably water, is fed through the liquid inlet. The CO2-containing gas and
`
`the aqueous liquid flows through the reaction chamber where carbonic anhydrase
`
`therein catalyses the hydration of CO2, thereby forming hydrogen ions and carbonate
`
`ions. Then, the solution containing the hydrogen ions and bicarbonate ions flows out
`
`30
`
`from the bioreactor via the liquid outlet and the gas free from CO~ flows out via the
`
`gas outlet.
`
`Akermin, Inc.
`Exhibit 1014
`Page 6
`
`

`

`WO 98/55210
`
`PCT/CA98/00541
`
`5
`
`According to a first preferred embodiment of the present invention, the
`
`apparatus comprises a second bioreactor in series with the upright bioreactor which
`
`is hereinafter called a first bioreactor. The second bioreactor is substantially similar
`
`to the first bioreactor. It comprises a liquid inlet connected with the liquid outlet of the
`
`5
`
`first bioreactor for receiving the liquid solution from the first bioreactor.
`
`A reaction chamber is provided for growing carbonic anhydrase. This reaction
`
`chamber is in fluid communication with the liquid inlet and comprises a plurality of
`
`inert organic supports mounted therein for covalently immobilizing carbonic
`
`anhydrase. The reaction chamber is in fluid communication with a gas outlet to
`
`t0
`
`evacuate a gas containing carbon dioxide obtained in the chamber.
`
`A liquid outlet is in fluid communication with the reaction chamber to evacuate
`
`water obtained in the reaction chamber.
`
`The second bioreactor preferably comprises means for controlling a pressure
`
`in the reaction chamber of the second bioreactor.
`
`15
`
`According to a second preferred embodiment of the present invention, the
`
`apparatus further comprises an ion exchanger having an inlet for receiving the liquid
`
`solution from the bioreactor.
`
`The present invention is also directed to the use of carbonic anhydrase or
`
`analog thereof covalently immobilized in a bioreactor to remove carbon dioxide from
`
`2O
`
`a CO2-containing gas, or to produce hydrogen and carbonate ions, or to the use of
`
`carbonic anhydrase or analog thereof covalently immobilized in a bioreactor to
`
`produce CO2 from enriched solutions of hydrogen and bicarbonate ions.
`
`A non restrictive description of preferred embodiments will now be given with
`
`reference to the appended drawings.
`
`25
`
`3O
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Figure 1 is a cross-sectional elevational view of a tower-type bioreactor
`
`according to a preferred embodiment of the present invention;
`
`Figure 2 is a schematic flow chart of a first preferred embodiment of the
`
`process according to the present invention; and
`
`Akermin, Inc.
`Exhibit 1014
`Page 7
`
`

`

`WO 98/55210
`
`PCT/CA98/O0541
`
`Figure 3 is a schematic flow chart of a second preferred embodiment of the
`
`process according to the present invention.
`
`6
`
`5
`
`DESCRIPTION OF PREFERRED EMBODIMENTS
`
`During the course of investigating possible uses of carbonic anhydrase for
`
`managing carbon dioxide accumulation in submarines, it was noted that covalent
`
`immobilization of monomeric enzymes could result in a functional enzyme system of
`
`increased stability. Moreover, there has been a dramatic increase in the use of
`
`10
`
`immobilized enzymes in a wide variety of biotechnological applications. Thus, it was
`
`reasoned that a bioreactor employing covalently immobilized carbonic anhydrase
`
`would provide an efficient biologically based system to manage carbon dioxide.
`
`Referring to Figure 1, an apparatus (2) for the management of CO2 according
`
`to a first preferred embodiment of the present invention is illustrated. This apparatus
`
`15
`
`(2) is devised primarily to extract or remove carbon dioxide from a CO2-containing
`
`gas and specifically transform this gas to hydrogen and bicarbonate ions. The
`
`apparatus (2) comprises an upright bioreactor (4) for growing carbonic anhydrase
`
`therein. The bioreactor (4) comprises a lower chamber (6) having a gas inlet (8) to
`
`receive a CO~-containing gas (10) and a liquid outlet (12) to evacuate from the
`
`2O
`
`bioreactor (4) a liquid solution (14) containing hydrogen ions and bicarbonate ions
`
`produced in the bioreactor (4). The bioreactor (4) further comprises an upper
`
`chamber (16) having a liquid inlet (18) to receive an aqueous liquid (20) and a gas
`
`outlet (22) to evacuate any gas (24) from the bioreactor (4).
`
`A reaction chamber (26) is disposed between the lower chamber (6) and the
`
`25
`
`upper chamber(16). As can be appreciated, the reaction chamber (26) of the
`
`bioreactor (4) illustrated is preferably divided in three sub-chambers. The reaction
`
`chamber (26) is in fluid communication with the lower chamber (6) and the upper
`
`chamber (16). Preferably, the liquid inlet (18) of the upper chamber (16) is connected
`
`to a pipe system (28) enclosed therein and having at least one liquid outlet (30) into
`
`3O
`
`the reaction chamber (26) such that the aqueous liquid (20) entering the bioreactor
`
`(4) flows directly into the reaction chamber (26). The reaction chamber (26) has a
`
`Akermin, Inc.
`Exhibit 1014
`Page 8
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`

`

`WO 98/55210
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`PCT/CA98/00541
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`lower surface permeable to gas and liquid such that the stream of CO2-containing
`
`gas entering the bioreactor (4) from the lower chamber (6) flows upwards into the
`
`reaction chamber (26) and the liquid in the reaction chamber (26) flows downwards
`
`towards and into the lower chamber (6).
`
`5
`
`The reaction chamber (26) is characterized in that it comprises a plurality of
`
`inert organic supports, schematically represented in Figure 1 as numeral reference
`
`(32), mounted therein for covalentty immobilizing carbonic anhydrase (33). These
`
`supports (32) are preferably made of ceramic such as silica, namely silica bud
`
`saddles or they may be made of polymer such as nylon, polystyrene and
`
`10
`
`polyethylene. The immobilization technique preferably uses one of the following
`
`bonding agents: imidocarbonate (silicon), carbondiimide (silica and nylon) and imine
`
`(silica and nylon). The polystyrene, nylon and polyethylene may be chemically
`
`modified with nitric acid to increase covalent bounding with the amine groups of the
`
`enzyme.
`
`15
`
`The CO~-containing feed gas (10) may consist of ambient air or any gaseous
`
`mixture containing carbon dioxide. The gas (10) may be filtered through a
`
`conventional filtering means (34) known in the art to concentrate the carbon dioxide
`
`and/or remove physical impurities. Control means for controlling the C02-containing
`
`gas flow (10) through the gas inlet (8) is provided. Thus, the gas (10) is then fed into
`
`20
`
`the lower portion (6) of the bioreactor body (4) using preferably an appropriate valve
`
`system (36) for volume and input velocity control. The bioreactor (4) is constructed
`
`as a packed tower, a classical design used in numerous applications.
`
`The preferably filtered aqueous or organic solvent (20) enters the bioreactor
`
`(4) from the upper chamber (16) and flows downwards either by gravity or pressure
`
`25
`
`controlled pumping. In the reaction chamber (26), the carbon dioxide of the input
`
`gas (10) will diffuse preferentially into the liquid phase (20) as the carbonic
`
`anhydrase transforms the gas into hydrogen and bicarbonate ions. The resulting
`
`liquid solution (14) of ions leaves the bioreactor (4) for subsequent use. The unique
`
`aspect of the invention is the use of carbonic anhydrase as a means to produce
`
`30
`
`enriched solutions of bicarbonate ions. There are several important variations
`
`possible with respect to the configuration of the bioreactor (4). The composition of
`
`Akermin, Inc.
`Exhibit 1014
`Page 9
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`

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`WO 98/55210
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`PCT/CA98/00541
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`8
`
`the input gas (10) may be varied along with the volume and speed of delivery. The
`
`bioreactor (4) may be deployed as a closed system so that the feed gas (10) can be
`
`compressed and/or enriched to enhance the kinetics of the mass transfer of the
`
`carbon dioxide from the gas to the liquid phase. There is a large number of methods
`
`5
`
`which may be employed to optimize the gas-liquid interaction in the reaction chamber
`
`(26), and hence the diffusion of carbon dioxide. The composition (e.g., pH) of the
`
`resulting ion solution may be modified according to need. This configuration can
`
`serve to extract carbon dioxide from a gas stream to produce a gas or gas mixture
`
`free of carbon dioxide.
`
`10
`
`Referring to Figure 2, this first bioreactor (4) design may preferably be
`
`coupled to an anion exchange system (39) with the resin in the hydroxide form. The
`
`ion exchanger (39) has an inlet (37) for receiving the liquid solution (14) from the
`
`bioreactor (4). Since the carbon dioxide hydration reaction produces hydrogen and
`
`bicarbonate ions in equimolar quantities, this solution may be fed directly into the ion
`
`15
`
`exchange system (37). The bicarbonate ions will be exchanged for the hydroxyl ions
`
`which will be free to combine with the hydrogen ions to form water. This system could
`
`be deployed as a carbon dioxide management system in any closed space such as
`
`a submarine. As illustrated in Figure 2, the solution (35) impoverished in hydrogen
`
`and bicarbonate ions may be recycled in the bioreactor (4).
`
`20
`
`Referring to Figure 3, the apparatus (2) for the management of carbon dioxide
`
`may further comprise a second bioreactor (38) similar to the first one and connected
`
`in series therewith. This particular configuration operates as a closed system. This
`
`system serves to produce carbon dioxide and operates in a manner similar to the
`
`individual bioreactor design of Figure 1. The liquid solution (14) containing a
`
`25
`
`relatively high concentration of hydrogen and bicarbonate ions produced in the first
`
`bioreactor (4) is fed to the second bioreactor (38) in which carbon dioxide is formed
`
`in the reaction catalysed by the carbonic anhydrase. This removal of the gas from
`
`the aqueous phase may be enhanced by the application of a slight (i.e., 7-9 mm Hg)
`
`negative pressure. The concentrated carbon dioxide can then be recovered for
`
`3O
`
`subsequent use.
`
`Akermin, Inc.
`Exhibit 1014
`Page 10
`
`

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`WO 98/55210
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`PCT/CA98/00541
`
`9
`
`Since this second bioreactor (38) is similar to the first one, it is schematically
`
`illustrated as a box in Figure 3. This second bioreactor (38) comprises a liquid inlet
`
`(40) connected with the liquid outlet (12) of the first bioreactor (4) for receiving the
`
`liquid solution (14) from the first bioreactor (4). The second bioreactor (38)
`
`comprises a reaction chamber similar to the reaction chamber (26) of the first
`
`bioreactor (4) for growing carbonic anhydrase. The reaction chamber is in fluid
`
`communication with the liquid inlet (40) and comprises a plurality of inert organic
`
`supports mounted therein for covatently immobilizing carbonic anhydrase. A gas
`
`outlet (42) is in fluid communication with the reaction chamber to evacuate carbon
`
`10
`
`dioxide obtained in the chamber. A liquid outlet (44) is in fluid communication with
`
`the reaction chamber to evacuate water (46) containing a small amount of hydrogen
`
`and bicarbonate ions obtained in the reaction chamber. The second bioreactor (38)
`
`may preferably comprise means for controlling a pressure in the reaction chamber
`
`As can be appreciated, the process and apparatus according to the present
`
`15
`
`invention may be used for the extraction, production and purification of carbon
`
`dioxide gas. The process may also be employed for the production of aqueous
`
`and/or organic solutions of bicarbonate ions and hydrogen ions using a precursor
`
`feed stream of gas containing carbon dioxide. It could be very advantageous to use
`
`such process and apparatus in any closed space such as a submarine.
`
`20
`
`Akermin, Inc.
`Exhibit 1014
`Page 11
`
`

`

`WO 98/55210
`
`PCT/CA98/00541
`
`WHAT IS CLAIMED IS:
`
`10
`
`1. A process for removing CO2 from a CO2-containing gas, characterized in that it
`
`comprises the step of:
`
`a) contacting the CO2-containing gas with an aqueous liquid (20) in a
`
`bioreactor (2) containing immobilized carbonic anhydrase (33) or an analog thereof,
`
`the carbonic anhydrase (33) catalysing the hydration of the CO2, thereby producing
`
`hydrogen ions and bicarbonate ions.
`
`10
`
`2. The process according to claim 1, characterized in that it further comprises, prior
`
`to step a), a step of:
`
`growing and covalently immobilizing carbonic anhydrase (33) or an analog
`
`thereof in the bioreactor (2).
`
`15
`
`3. The process according to claim 2, characterized in that the step of immobilizing
`
`carbonic anhydrase (33) in the bioreactor (2) comprises the step of covalently
`
`binding carbonic anhydrase (33) to an inert solid support (32) mounted in the
`
`bioreactor (2).
`
`2O
`
`4. The process according to anyone of claims 1 to 3, characterized in that it further
`
`comprises, after step a), the step of:
`
`b) feeding the hydrogen ions and bicarbonate ions obtained in step a) into a
`
`second bioreactor (38) containing immobilized carbonic anhydrase which catalyses
`
`the conversion of the hydrogen ions and the bicarbonate ions into CO~ and water.
`
`25
`
`5. The process according to anyone of claims 1 to 3, characterized in that it further
`
`comprises, after step a), the step of:
`
`- feeding the hydrogen ions and bicarbonate ions obtained in step a) into an
`
`ion exchanger (39) containing hydroxyl ions so that the bicarbonate ions are
`
`3O
`
`exchanged for the hydroxyl ions which are then free to combine with hydrogen ions
`
`to form water.
`
`Akermin, Inc.
`Exhibit 1014
`Page 12
`
`

`

`WO 98/55210
`
`PCT/CA98/00541
`
`11
`
`6. The process according to anyone of claims 1 to 5, characterized in that step a)
`
`comprises the steps of:
`
`directing a stream of the CO2-containing gas upwards into the bioreactor (2)
`
`and directing a stream of the aqueous liquid (20) downwards such that the stream
`
`of CO2-containing gas is countercurrent to the stream of the aqueous solution.
`
`7. The process according to anyone of claims
`
`1 to 6, characterized in that it
`
`comprises, prior to step a), a step of:
`
`filtering the CO~-containing gas.
`
`8. The process according to anyone of claims 1
`
`to 7, characterized in that the
`
`aqueous liquid consists of water.
`
`9. An apparatus for the management of CO~ comprising:
`
`an upright bioreactor (2) containing carbonic anhydrase therein or an analog
`
`thereof, the bioreactor (2) comprising:
`
`a bottom chamber (6) having a gas inlet (8) to receive a COs-containing
`
`gas (10) and a liquid outlet (12) to evacuate from the bioreactor (2) a liquid solution
`
`(14) containing hydrogen ions and bicarbonate ions produced in the bioreactor (2);
`
`an upper chamber (16) having a liquid inlet (18) to receive an aqueous
`
`liquid (20) and a gas outlet (22) to evacuate any gas (24) from the bioreactor (2);
`a reaction chamber (26) disposed between and being in fluid
`
`communication with the bottom chamber (6) and the upper chamber (16), the
`
`reaction chamber (26) being characterized in that it comprises a plurality of inert
`
`10
`
`15
`
`2O
`
`25
`
`solid supports (32) mounted therein for covalently immobilizing carbonic anhydrase
`
`(33).
`
`10. An apparatus as claimed in claim 9, characterized in that it further comprises an
`
`ion exchanger (39) having an inlet (37) for receiving said liquid solution (14) from the
`
`30
`
`bioreactor (2).
`
`Akermin, Inc.
`Exhibit 1014
`Page 13
`
`

`

`WO 98/55210
`
`PCT/CA98/00541
`
`12
`
`11. An apparatus as claimed in claims 9 or 10, characterized in that it further
`
`comprises filtering means (34) for filtering the C02-containing gas (10) prior to
`
`feeding it to the gas inlet (8).
`
`5
`
`12. An apparatus as claimed in anyone of claims 9 to 11, characterized in that it
`
`comprises control means for controlling the C02-containing gas (10) flow through the
`
`gas inlet (8).
`
`13. An apparatus as claimed in claim 12, characterized in that the control means
`
`10
`
`comprises a valve (36) mounted on the gas inlet.
`
`14. An apparatus as claimed in anyone of claims 9 to 13, characterized in that it
`
`comprises a second bioreactor (38) in series with said upright bioreactor (2) which
`
`is hereinafter called a first bioreactor (2), said second bioreactor (38) comprising:
`
`15
`
`a liquid inlet (40) connected with the liquid outlet (12) of the first bioreactor (2)
`
`for receiving said liquid solution (14) from the first bioreactor (2);
`
`a reaction chamber containing carbonic anhydrase, the reaction chamber
`
`being in fluid communication with the liquid inlet (40) and comprising a plurality of
`
`inert support mounted therein for covalently immobilizing carbonic anhydrase;
`
`2O
`
`a gas outlet (42) in fluid communication with the reaction chamber (38) to
`
`evacuate a gas phase containing carbon dioxide obtained in the chamber (38); and
`
`a liquid outlet (44) in fluid communication with the reaction chamber (38) to
`
`evacuate a liquid phase (46) obtained in the reaction chamber (38).
`
`25
`
`15. An apparatus according to claim 14, characterized in that the second bioreactor
`
`(38) comprises means for controlling a pressure in the reaction chamber of the
`
`second bioreactor.
`
`16. Use of carbonic anhydrase or an analog thereof covalently immobilized in a
`
`30
`
`bioreactor to remove carbon dioxide from a C02-containing gas.
`
`Akermin, Inc.
`Exhibit 1014
`Page 14
`
`

`

`WO 98/55210
`
`PCT/CA98/00541
`
`13
`
`17. Use of carbonic anhydrase or an analog thereof covalently immobilized in a
`
`bioreactor to produce C02 from enriched solutions of hydrogen and bicarbonate ions.
`
`18. Use of carbonic anhydrase or an analog thereof covalently immobilized in a
`
`5
`
`bioreactor to produce enriched solutions of hydrogen and bicarbonate ions from a
`
`C02-containing gas.
`
`Akermin, Inc.
`Exhibit 1014
`Page 15
`
`

`

`WO 98/55210
`
`PCT/CA98/00541
`
`18
`
`E
`
`~4
`
`32~
`
`33
`
`f 33
`
`32
`
`36
`
`10
`
`12
`
`FIG. 1
`
`Akermin, Inc.
`Exhibit 1014
`Page 16
`
`

`

`WO 98/55210
`
`PCT/CA98/00541
`
`2/2
`
`2
`
`LOW H÷, HCO3-
`
`4
`
`10) 12
`
`FIG. 2
`
`’HIGH H ÷, HCO3-
`L
`
`37
`
`14
`
`46
`
`LOW C02. ~L/$ I
`
`LOW H÷, HCO3-
`
`22 ~-
`
`4
`
`~ co2 {EXIT)
`
`,
`
`38
`
`I
`
`HIGH H; HCO3-
`
`14
`
`FIG. 3
`
`Akermin, Inc.
`Exhibit 1014
`Page 17
`
`

`

`INTERNATIONAL SEARCH REPORT
`
`Int~ ional Applioation No
`
`PCT/CA 98/00541
`
`A. CLASSIFICATION OF S~JBJECT MAI-I’ER
`IPC 6 BOLD53/62 BOID53/84 C 12Mi/40
`
`A, ccording tO International Patent Classtication(IPC or to both nations classification and
`
`B. F~ELDS SEARCHED
`
`Minimum documentation searched (classification system follower b~ classification symbols~
`IPC 6 B01D C12M
`
`documentation searched other than minimumdocumentation to the extent that such documents are included in the fields searched
`
`Electronic data base consuited during the international search (hems of data base and, where practical, search terms used)
`
`C. DOCUME,,N, TS CONSID, ERED TO BE RELEVANT
`
`Category : Citation ot document, with indication, where appropriate, of the relevant passages Retevant to claim No.
`
`X
`
`WO 96 40414 A (TRACHTENBERG MICHAEL C) 19
`December 1996
`see page 4, line 14 - page 5, line 22
`see page 9, line 18-30
`see example 2
`
`EP 0 511 719 A (AQUANAUTICS CORP) 4
`November 1992
`see page 25, line 33 - page 26,
`figures 5-7
`see page 22, line 19-32
`see page 23, ]fne 19-47
`
`line 18;
`
`--/--
`
`~ Further documents are listed in the continuation of box C.
`
`Special categories of cited documents :
`
`"A" document defining the general state of the art which is net
`considered to be o! particular relevance
`"E" eadier document Dut published on or after the international
`ti~ing date
`
`"L" document which may throw doubts on priority claim s) or
`which is cited to establish the publicat ondate of anotl~er
`ciation or other special reason (as spe~l~ed)
`
`"0" document referdng to an oral ~isclosurs, use, exhibtion or
`other means
`
`"P" document published prior to the international filing date but
`later than the pnor~y date claimed
`
`E)ate of the actual completion of theinternational search
`
`24 September 1998
`
`Name and mailing address o! the ISA
`
`European Patent Office, P.B. 5818 Patent~aan 2
`NL - 2280 HV Rijswijk
`Tel. (+31-70) 340-2040, Tx. 31 651 epo r~,
`Fax: (+31-70) 340-3016
`
`Form PCT/ISN210 (second S~lest) (July 1992)
`
`F
`
`Patent family memDers are listed
`
`annex.
`
`"T" tater document publislled afler the international filing
`or prionty date and not in co