# US 8,771,405 B2 · Gas filter with chamber comprising carbon nanotubes for filtering CO2 > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,405 B2 - Document ID: US8771405B2 - Status: Granted - Kind: B2 - Application number: 13/638,595 - Filed: 2011-03-29 - Published: 2013-02-21 - Granted: 2014-07-08 - Earliest claimed: 2010-03-31 - Applicants: Dimitris Drikakis - Inventors: Dimitris Drikakis - Web page: https://patentgrep.com/patent/US8771405B2 ## CPC - B01D 53/0407: {Constructional details of adsorbing systems} - B01D 53/02: by adsorption, e.g. preparative gas chromatography {(solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01)} - B01J 20/205: {Carbon nanostructures, e.g. nanotubes, nanohorns, nanocones, nanoballs (carbon nanotubes per se C01B32/15)} - B01J 20/28097: {being coated, filled or plugged with specific compounds} - B01J 20/3204: {Inorganic carriers, supports or substrates} - B01J 20/3257: {the functional group or the linking, spacer or anchoring group as a whole comprising at least one of the heteroatoms nitrogen, oxygen or sulfur together with at least one silicon atom, these atoms not being part of the carrier as such} - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - B01D 53/0446: {Means for feeding or distributing gases} - B01D 2253/102: Carbon - B01D 2257/504: Carbon dioxide - B01D 2258/01: Engine exhaust gases - B01D 2258/06: Polluted air - B01D 2259/40077: Direction of flow - B01D 2259/4575: in aeroplanes or space ships - Y02C 20/40: of CO2 - 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) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG] ## Abstract A gas filter comprises a housing (30) having a gas inlet (55), a gas outlet (65) and at least one chamber (70) therebetween containing carbon nanotubes (110). The chamber (70) has a port (90) and is configured for simultaneous gas ingress to and gas egress from the carbon nanotubes (110) through the port (90). ## Claims ### Claim 1 A gas filter comprising: a housing having a gas inlet comprising a first port, a gas outlet comprising a second port and at least one chamber therebetween containing carbon nanotubes, the chamber having a third port for simultaneous gas ingress to and gas egress from the carbon nanotubes through said third port. ### Claim 2 (depends on 1) A gas filter according to claim 1, wherein the gas filter is configured to filter out carbon dioxide. ### Claim 3 (depends on 1) A gas filter according to claim 1, wherein the carbon nanotubes are single-walled carbon nanotubes. ### Claim 4 (depends on 1) A gas filter according to claim 1, wherein the carbon nanotubes are multi-walled carbon nanotubes. ### Claim 5 (depends on 1) A gas filter according to claim 1, wherein the carbon nanotubes are modified carbon nanotubes. ### Claim 6 (depends on 5) A gas filter according to claim 5, wherein the carbon nanotubes are modified via 3-aminopropyl-triethoxysilane. ### Claim 7 (depends on 1) A gas filter according to claim 1, wherein the carbon nanotubes are arranged in bundles. ### Claim 8 (depends on 1) A gas filter according to claim 1, wherein the gas filter consists of a single chamber. ### Claim 9 (depends on 1) A gas filter according to claim 1, wherein the gas filter comprises multiple chambers. ### Claim 10 (depends on 9) A gas filter according to claim 9 and comprising at least four chambers. ### Claim 11 (depends on 1) A gas filter according to claim 1, wherein the chamber is cylindrical and the third port defines a circular area through which gas ingress and egress takes place. ### Claim 12 (depends on 1) A gas filter according to claim 1, wherein the chamber is annular in cross section. ### Claim 13 (depends on 12) A gas filter according to claim 12, wherein the third port defines an annular area through which gas ingress and egress takes place. ### Claim 14 (depends on 12) A gas filter according to claim 12 and comprising a plurality of concentric chambers. ### Claim 15 (depends on 14) A gas filter according to claim 14, wherein the chambers are defined between a plurality of concentric, axially-extending walls. ### Claim 16 (depends on 12) A gas filter according to claim 12, wherein the third port defines a cylindrical area through which gas ingress and egress takes place. ### Claim 17 (depends on 16) A gas filter according to claim 16 and comprising a plurality of co-axial annular chambers. ### Claim 18 (depends on 17) A gas filter according to claim 17, wherein the chambers are defined by a plurality of axially-spaced, radially-extending walls. ### Claim 19 (depends on 1) A gas filter according to claim 1, wherein the gas inlet of the gas filter is configured to promote gas flow circulation around the carbon nanotubes in the at least one chamber. ### Claim 20 (depends on 19) A gas filter according to claim 19, wherein the gas inlet is configured to promote flow swirl and jet-like instabilities. ### Claim 21 (depends on 1) A gas filter according to claim 1, wherein the first port has a circular section. ### Claim 22 (depends on 21) A gas filter according to claim 21, wherein the gas inlet comprises multiple of the first ports of circular section. ### Claim 23 (depends on 1) A gas filter according to claim 1, wherein the axis of the third port of the at least one chamber is substantially parallel to the flow axis of the gas inlet. ### Claim 24 (depends on 23) A gas filter according to claim 23, wherein the gas inlet is formed in a first wall of the housing and the third port of the at least one chamber is formed in a second wall facing the first wall. ### Claim 25 (depends on 1) A gas filter according to claim 1, wherein the axis of the third port of the at least one chamber is substantially perpendicular to the flow axis of the gas inlet. ### Claim 26 (depends on 1) A gas filter according to claim 1, wherein at least one nanofilter is placed at the gas inlet, thereby allowing the gas mixture to flow into the gas filter while preventing the nanotubes flowing out of the gas filter. ### Claim 27 (depends on 1) A gas filter according to claim 1, wherein at least one nanofilter is placed at the gas outlet of the gas filter, thereby allowing the filtered gas mixture to flow out of the gas filter while preventing the nanotubes flowing out of the gas filter. ### Claim 28 (depends on 1) A gas filter according to claim 1, wherein the housing is a cylinder. ### Claim 29 (depends on 28) A gas filter according to claim 28, wherein the gas inlet is formed in a first wall at one end of the cylinder, the first wall being releasably attached to the housing. ### Claim 30 (depends on 1) A gas filter according to claim 1, wherein the flow axis of the gas outlet is substantially parallel to the flow axis of the gas inlet. ### Claim 31 (depends on 30) A gas filter according to claim 30, wherein the gas outlet is formed in a second wall at the opposite end of the cylinder to the first wall. ### Claim 32 (depends on 1) A gas filter according to claim 1, wherein the flow axis of the gas outlet is substantially perpendicular to the flow axis of the gas inlet. ### Claim 33 (depends on 32) A gas filter according to claim 32, wherein the gas outlet is formed in the side, circumferential wall of the cylinder. ### Claim 34 A gas filtration device comprising: a gas filter having a housing with a gas inlet comprising a first port, a gas outlet comprising a second port, and at least one chamber therebetween containing carbon nanotubes, the chamber having a third port for simultaneous gas ingress to and gas egress from the carbon nanotubes through said third port; an entry flow section to supply gas to the gas inlet of the gas filter; and a gas exhaust section to exhaust gas from the gas outlet of the gas filter. ### Claim 35 (depends on 34) A gas filtration device according to claim 34, wherein the entry section comprises at least one nanofilter. ### Claim 36 (depends on 34) A gas filtration device according to claim 34, wherein the entry section comprises a mass flow meter. ### Claim 37 (depends on 34) A gas filtration device according to claim 34, wherein the entry section comprises a CO.sub.2 flow sensor. ### Claim 38 A gas filtration system comprising: a gas filter having a housing with a gas inlet comprising a first port, a gas outlet comprising a second port, and at least one chamber therebetween containing carbon nanotubes, the chamber having a third port for simultaneous gas ingress to and gas egress from the carbon nanotubes through said third port; and a compressor for feeding gas into the gas inlet. ### Claim 39 (depends on 38) A gas filtration system according to claim 38, wherein the compressor is configured to compress gas by a factor of at least five. ### Claim 40 Method of filtering gas, comprising the steps of: providing a gas filter comprising a housing having a gas inlet comprising a first port, a gas outlet comprising a second port and at least one chamber therebetween containing carbon nanotubes, the chamber having a third port; and flowing gas into the first gas inlet port, thereafter simultaneously to and then from the carbon nanotubes through said third port, thereafter out of the second gas outlet port. ### Claim 41 (depends on 40) Method according to claim 40, wherein the gas is carbon dioxide. ### Claim 42 (depends on 40) Method according to claim 40, wherein the carbon nanotubes are single-walled carbon nanotubes. ### Claim 43 (depends on 40) Method according to claim 40, wherein the carbon nanotubes are multi-walled carbon nanotubes. ### Claim 44 (depends on 40) Method according to claim 40, wherein the carbon nanotubes are modified carbon nanotubes. ### Claim 45 (depends on 44) Method according to claim 44, wherein the carbon nanotubes are modified via 3-aminopropyl-triethoxysilane. ### Claim 46 (depends on 40) Method according to claim 40, wherein the carbon nanotubes are arranged in bundles. ### Claim 47 (depends on 40) Method according to claim 40, wherein the gas filter consists of a single chamber. ### Claim 48 (depends on 40) Method according to claim 40, wherein the gas filter comprises multiple chambers. ### Claim 49 (depends on 48) Method according to claim 48, wherein the gas filter comprises at least four chambers. ### Claim 50 (depends on 40) Method according to claim 40, wherein the chamber is cylindrical and has a third port defining a circular area through which gas ingress and egress takes place. ### Claim 51 (depends on 40) Method according to claim 40, wherein the chamber is annular in cross section. ### Claim 52 (depends on 51) Method according to claim 51, wherein the chamber has a third port defining an annular area through which gas ingress and egress takes place. ### Claim 53 (depends on 51) Method according to claim 51, wherein the gas filter comprises a plurality of concentric chambers. ### Claim 54 (depends on 53) Method according to claim 53, wherein the chambers are defined between a plurality of concentric, axially-extending walls. ### Claim 55 (depends on 51) Method according to claim 51, wherein the chamber has a third port defining a cylindrical area through which gas ingress and egress takes place. ### Claim 56 (depends on 55) Method according to claim 55, wherein the gas filter comprises a plurality of co-axial annular chambers. ### Claim 57 (depends on 56) Method according to claim 56, wherein the chambers are defined by a plurality of axially-spaced, radially-extending walls. ### Claim 58 (depends on 40) Method according to claim 40, wherein the gas inlet is configured to promote gas flow circulation around the carbon nanotubes in the at least one chamber. ### Claim 59 (depends on 58) Method according to claim 58, wherein the gas inlet is configured to promote flow swirl and jet-like instabilities. ### Claim 60 (depends on 40) Method according to claim 40, wherein the first port has a circular section. ### Claim 61 (depends on 60) Method according to claim 60, wherein the gas inlet comprises multiple first ports of circular section. ### Claim 62 (depends on 40) Method according to claim 40, wherein the axis of the third port is substantially parallel to the flow axis of the gas inlet. ### Claim 63 (depends on 62) Method according to claim 62, wherein the first port is formed in a first wall of the housing and the third port is formed in a second wall facing the first wall. ### Claim 64 (depends on 40) Method according to claim 40, wherein the axis of the third port is substantially perpendicular to the flow axis of the gas inlet. ### Claim 65 (depends on 40) Method according to claim 40, wherein at least one nanofilter is placed at the gas inlet, thereby allowing the gas mixture to flow into the gas filter while preventing the nanotubes flowing out of the gas filter. ### Claim 66 (depends on 40) Method according to claim 40, wherein at least one nanofilter is placed at the gas outlet of the gas filter, thereby allowing the filtered gas mixture to flow out of the gas filter while preventing the nanotubes flowing out of the gas filter. ### Claim 67 (depends on 40) Method according to claim 40, wherein the housing is a cylinder. ### Claim 68 (depends on 67) Method according to claim 67, wherein the gas inlet is formed in a first wall at one end of the cylinder, the first wall being releasably attached to the housing. ### Claim 69 (depends on 40) Method according to claim 40, wherein the flow axis of the gas outlet is substantially parallel to the flow axis of the gas inlet. ### Claim 70 (depends on 69) Method according to claim 69, wherein the gas outlet is formed in a second wall at the opposite end of the cylinder to the first wall. ### Claim 71 (depends on 40) Method according to claim 40, wherein the flow axis of the gas outlet is substantially perpendicular to the flow axis of the gas inlet. ### Claim 72 (depends on 71) Method according to claim 71, wherein the gas outlet is formed in the side, circumferential wall of the cylinder.