# US 11,306,280 B2 · Systems and methods of atmospheric carbon dioxide enrichment and delivery to photobioreactors via membrane carbonation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,306,280 B2 - Document ID: US11306280B2 - Status: Granted - Kind: B2 - Application number: 15/564,862 - Filed: 2016-04-07 - Published: 2018-04-19 - Granted: 2022-04-19 - Earliest claimed: 2015-04-07 - Assignees: Arizona Board of Regents on behalf of Arizona State University - Applicants: Bruce Rittmann; Klaus Lackner; Justin Flory; Megha Patel; Allen Wright - Inventors: Bruce Rittmann; Klaus Lackner; Justin Flory; Megha Patel; Allen Wright - Web page: https://patentgrep.com/patent/US11306280B2 ## CPC - C12M 21/02: {Photobioreactors (culturing algae A01G33/00, A01H4/001, C12N1/12)} - C12M 29/04: {Filters; Permeable or porous membranes or plates, e.g. dialysis} - C12M 41/26: {of pH} - C12M 41/34: {of gas} - B01D 53/04: with stationary adsorbents {(B01D53/025 takes precedence)} - B01D 2253/206: Ion exchange resins - B01D 2257/504: Carbon dioxide - Y02C 20/40: of CO2 - C12M: APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; {APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS} - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG] ## Abstract The present application focuses on systems and methods that utilize one or more carbon dioxide (CO2) sorbent substrates and a swing cycle, e.g., a moisture swing cycle, to increase the partial pressure of the CO2 in a gaseous feedstock, which is delivered through a membrane to a bioreactor, such as a membrane carbonation photobioreactor. Such systems and processes offer an effective means for concentrating and capturing CO2 obtained from air and delivering the concentrated CO2 to a photobioreactor through a membrane. ## Claims ### Claim 1 A system for growing phototrophic microorganisms comprising: a bioreactor comprising a microorganism-containing liquid and a membrane system; a collector comprising a sorbent for capturing CO2 from air; a regeneration unit configured to: receive the collector within an enclosure, regenerate the sorbent by causing it to release sorbed CO2, and capture the released CO2; a storage tank coupled to the regeneration unit, the storage tank comprising a headspace, the storage tank being configured to receive the released CO2 from the regeneration unit and containing at least a portion of the released CO2 from the regeneration unit as a storage solution and at least a portion of the released CO2 from the regeneration unit as a CO2 gas, the headspace of the storage tank containing the CO2 gas; and a pump coupled to the headspace and configured to pump the CO2 gas from the headspace to a bioreactor via membrane system, the membrane system comprising one or more membranes configured for diffusion-driven delivery of a CO2 gas across the one or more membranes to the microorganism-containing liquid of the bioreactor, a first side of a membrane of the one or more membranes configured to interface with a CO2 gas stream from the storage tank and a second side of the membrane of the one or more membranes configured to interface with a portion of the microorganism-containing liquid in the bioreactor, the second side different than the first side. ### Claim 2 (depends on 1) The system of claim 1, where the collector comprises a composite material comprising the sorbent and having a hydrophobic surface. ### Claim 3 (depends on 1) The system of claim 1, where: the sorbent comprises a composite material having a surface, and a porous hydrophobic material is disposed on the surface. ### Claim 4 (depends on 3) The system of claim 3, where the porous hydrophobic material is one or more of the following: a polyolefin, a fluoropolymer, and a fluoropolymeric membrane. ### Claim 5 (depends on 1) The system of claim 1, where the pH of the liquid in the bioreactor is maintained between 7 to 10, between 8.5 to 9.5, or between 8.8 to 9.2. ### Claim 6 (depends on 1) The system of claim 1, where the pH of the liquid in the bioreactor is maintained at a pH between 10 to 11 or between 0 to 7. ### Claim 7 (depends on 1) The system of claim 1, where the membrane system is disposed in a lower light area within the bioreactor. ### Claim 8 (depends on 1) The system of claim 1, where the one or more membranes have a membrane specific surface area at or less than 25 m−1, less than 20 m−1, less than 18 m−1, less than 15 m−1, less than 12 m−1, less than 5 m−1, less than 1 m−1 or less than 0.5 m−1. ### Claim 9 (depends on 1) The system of claim 1, where a surface area of the one or more membranes interfacing with the liquid is between 0.005 to 0.025 m2 per L of algae-containing liquid. ### Claim 10 (depends on 1) The system of claim 1, where a gaseous flow of the CO2 gas received by the membrane system comprises between 3% and 5% CO2, between 5% and 10% CO2, between 10% and 30% CO2, between 30% and 50% CO2, between 50% and 80% CO2, or between 80% and 100% CO2. ### Claim 11 (depends on 1) The system of claim 1, wherein the regeneration unit is configured to regenerate the sorbent and release the CO2 from the sorbent by causing one or more of a humidity increase, a temperature increase, and a pressure decrease within the regeneration unit. ### Claim 12 (depends on 1) The system of claim 1, wherein the one or more membranes comprise a plurality of hollow fiber membranes through which the CO2 from the storage tank passes. ### Claim 13 (depends on 1) The system of claim 1, where the sorbent is disposed on a sheet that is configured to be rolled and disposed in the regeneration unit and unrolled and exposed to the air. ### Claim 14 (depends on 1) The system of claim 1, where the sorbent is disposed on a sheet that is configured to be folded and disposed in the regeneration unit and unfolded and exposed to the air. ### Claim 15 (depends on 1) The system of claim 1, where the storage solution comprises bicarbonate and carbonate. ### Claim 16 (depends on 15) The system of claim 15, where the pump is configured to extract CO2 from the storage solution by causing a shift in pressure, temperature, or a combination thereof. ### Claim 17 (depends on 16) The system of claim 16, where the pump is configured to cause a shift in a temperature of the storage solution. ### Claim 18 (depends on 16) The system of claim 16, where a gaseous flow passes through the headspace having a CO2 partial pressure that is lower than a vapor pressure of CO2 for the storage solution. ### Claim 19 (depends on 1) The system of claim 1, wherein the sorbent comprises a plurality of quaternary amines or carbonate perfused activated carbon. ### Claim 20 (depends on 1) The system of claim 1, further comprising a compressor configured to compress CO2, either extracted from the storage solution or released from the sorbent during regeneration, to gas pressures at or greater than 1, 2, 3, 4, or 5 atm. ### Claim 21 (depends on 1) The system of claim 1, wherein the one or more membranes comprise a plurality of hollow fiber membranes configured to receive CO2 from the storage tank. ### Claim 22 (depends on 1) The system of claim 1, wherein the bioreactor is configured to send gas, after the gas has passed through the membrane, to the storage tank to increase a CO2 concentration and the storage tank is configured to receive the gas from the bioreactor and to increase its CO2 concentration. ### Claim 23 (depends on 1) A method of growing an algae culture comprising: providing the system of claim 1; exposing a sorbing substrate comprising the sorbent to an atmosphere comprising CO2 to capture a portion of the CO2; causing a release, inside the enclosure, of the captured CO2 from the sorbing substrate by altering pressure, humidity, temperature, or a combination thereof within the enclosure; and transferring a gas flow containing the released CO2 to the one or more membranes disposed in the bioreactor comprising a culture of phototrophic microorganisms, wherein the concentration of CO2 within the gas flow is higher than atmospheric concentration by at least 10-fold, wherein the released CO2 disposed within the one or more membranes diffuses across the one or more membranes and into the culture of phototrophic microorganisms. ### Claim 24 (depends on 23) The method of claim 23, where the pH of the liquid in the bioreactor is maintained at about a pH of 9. ### Claim 25 (depends on 23) The method of claim 23, where causing the release of the captured CO2 comprises applying an aqueous solution to the sorbing substrate. ### Claim 26 (depends on 23) The method of claim 23, comprising dissolving the CO2 released inside the enclosure in an aqueous solution. ### Claim 27 (depends on 26) The method of claim 26, comprising storing the aqueous solution with the dissolved CO2 in the storage tank. ### Claim 28 (depends on 26) The method of claim 26, comprising driving the CO2 out of the aqueous solution and into the gas flow.