Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/34—Chemical or biological purification of waste gases
  • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
  • B01D53/86—Catalytic processes
  • B01D53/864—Removing carbon monoxide or hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B32/00—Carbon; Compounds thereof
  • C01B32/50—Carbon dioxide
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2256/00—Main component in the product gas stream after treatment
  • B01D2256/22—Carbon dioxide
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2257/00—Components to be removed
  • B01D2257/50—Carbon oxides
  • B01D2257/502—Carbon monoxide
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2258/00—Sources of waste gases
  • B01D2258/02—Other waste gases
  • B01D2258/0283—Flue gases

Definitions

• the present disclosure generally relates to a system and method for generating a carbon dioxide stream. More particularly, the present disclosure relates to generating a carbon dioxide stream in a flue gas stream processing system employing a chemical looping combustion system.
• CLC Chemical looping combustion
• air reactor an air reactor and a fuel reactor.
• a solid oxygen carrier which may be a metal, transfers the oxygen from the air to the fuel.
• the fuel is fed to the fuel reactor where it is oxidized by the oxygen carrier and the oxygen is carrier is reduced and retuned to the air reactor, where it is oxidized and the loop of oxidizing the fuel and reducing the carrier continues.
• the exit stream from the fuel reactor commonly referred to as the flue gas, typically contains C0 2 and water vapor. However, depending on the fuel, the flue gas may also contain trace contaminants.
• the water vapor in the flue gas is separated from the C0 2 by cooling and condensation, while the C0 2 is liquefied or compressed for further transport.
• the C0 2 stream may be contaminated with products of incomplete combustion, such as carbon monoxide (CO), hydrogen (H 2 ), and methane (CH 4 ). Additionally, the flue gas stream may be diluted with air, which may in-leak to the boiler.
• CO carbon monoxide
• H 2 hydrogen
• CH 4 methane
• Contaminants such as CO, H 2 , and CH 4 are more difficult to liquefy than C0 2 during liquification of the C0 2 .
• the contaminants take the form of a non-condensable phase commonly referred to as a exhaust gas.
• the level of contaminates within the exhaust gas as is often too high to be released to the atmosphere without further treatment. Recycling of the exhaust gas to the fuel reactor would result in gradual accumulation of N 2 and other inert gases in the flue gas and may also dilute the C0 2 stream, thereby reducing the efficiency of the CLC system.
• a method or system for processing the exhaust gas in an efficient way without impacting the CLC system is desired.
• a method of generating a liquefied carbon dioxide stream comprising: generating a flue gas stream including carbon monoxide and water vapor; subjecting the flue gas stream to an oxidation catalyst for oxidizing the carbon monoxide, thereby generating a carbon dioxide rich flue gas stream; and processing the carbon dioxide rich flue gas stream to form a liquefied carbon dioxide stream.
• a flue gas stream processing system comprising: a fuel reactor for combusting a fuel to generate a flue gas stream including water vapor, carbon monoxide and carbon dioxide; an oxidation catalyst downstream of the fuel reactor, the oxidation catalyst configured to receive the flue gas stream and oxidize the carbon monoxide to form a carbon dioxide rich flue gas stream; and a processing unit to liquefy carbon dioxide in the carbon dioxide rich flue gas stream and generate an exhaust gas.
• a method for reducing an amount of contaminants released by a flue gas stream processing system comprising: generating a flue gas stream by combustion of a fuel in a fuel reactor of a chemical looping combustion system, the flue gas stream includes water vapor and carbon monoxide; forming a liquefied carbon dioxide stream by removing water vapor and carbon monoxide from the flue gas stream; generating an exhaust gas during formation of the liquefied carbon dioxide stream; and providing at least a portion of the exhaust gas to an air reactor in the chemical looping combustion system, thereby reducing an amount of contaminants released by a flue gas stream processing system.
• FIGURE 1 is a schematic block diagram of one embodiment of the system disclosed herein;
• FIGURE 2 is a schematic block diagram of one embodiment of the system disclosed herein.
• FIG. 1 illustrates a flue gas stream processing system 100 having a
• the combustion system 120 may be any system capable of combusting a fuel 122 to form a flue gas 124.
• the combustion system 120 illustrated in FIG. 1 is a chemical looping combustion system that includes an air reactor 126 and a fuel reactor 128.
• the flue gas stream processing system 100 is not limited in this regard since the combustion system 120 may be other combustion systems, including, but not limited to boilers, furnaces, and the like.
• the chemical looping combustion system 120 includes an oxygen carrier 130, which transfers oxygen from the air present in the air reactor 126 to the fuel 122 provided to the fuel reactor 128.
• the fuel 122 is oxidized by the oxygen carrier 130 in the fuel reactor 128 and the oxygen carrier is reduced and returned to the air reactor 126 as a reduced oxygen carrier 132.
• the reduced oxygen carrier 132 is oxidized in the air reactor 126 and the loop of oxidizing the fuel 122 and reducing the oxygen carrier 130 continues.
• the oxygen carrier 130 may be a metal, such as, but not limited to nickel, copper, iron, manganese, cadmium, and cobalt.
• the chemical loop combustion system 120 may include one or more cyclones 134, which facilitate the separation of the oxygen carrier 130 from depleted air and separation of the flue gas stream 124 from the reduced oxygen carrier 132.
• Oxidation of the fuel 122 in the fuel reactor 128 produces the flue gas stream
• the flue gas stream 124 typically contains carbon monoxide (CO) carbon dioxide (C0 2 ) and water vapor. However, depending on the fuel, the flue gas stream 124 may also contain varying concentrations of trace contaminants, such as, but not limited to sulfur oxides (SOx), nitrogen oxides (NOx), mercury, hydrogen (H 2 ), and methane (CH 4 ). The flue gas stream 124 may also include contaminants such as fly ash as well as unburnt fuel (referred to as "unburnts").
• the oxygen required for the oxidationof the carbon monoxide can be introduced by an air stream 152 that leaks into a boiler 154, through which the flue gas stream 124 passes. Oxidation of carbon monoxide forms carbon dioxide, which can be condensed and liquefied in the processing unit 150.
• the leakage of air stream 152 into the boiler 154 is typically about 2% of the volume flue of the flue gas stream 124.
• Removal of the contaminants present in the flue gas stream 124 may be conducted by providing the flue gas stream to a contaminant removal system 140 prior to introduction to a processing unit 150.
• contaminant removal systems 140 include, but are not limited to, particle removable devices, desulfurization systems such as wet flue gas desulfurization (WFGD) or dry flue gas desulfurization (DFGD), nitrogen oxide (NOx) removal systems, mercury removal systems (e.g., activated carbon), and the like, and combinations thereof. Removal of at least a portion of the contaminants from the flue gas stream 124 produces a carbon dioxide rich flue gas stream 124', which is introduced to the processing unit 150.
• WFGD wet flue gas desulfurization
• DFGD dry flue gas desulfurization
• NOx nitrogen oxide
• mercury removal systems e.g., activated carbon
• the processing unit 150 condenses and liquefies the carbon dioxide present in the carbon dioxide rich flue gas stream 124', while removing any remaining contaminants to produce a carbon dioxide stream 156 and an exhaust gas 158.
• the carbon dioxide stream 156 is transported in liquefied form to another location for compression, use and/or storage.
• the exhaust gas 158 typically contains material that was not removed from the flue gas stream 124, such as nitrogen, hydrogen, oxygen and carbon monoxide.
• the carbon monoxide present in the flue gas stream 124 is less than about one percent by volume (1% by vol.) of the carbon dioxide concentration in the flue gas stream, at least a portion of the exhaust gas 158 may be returned to the air reactor 126.
• Measurement of the carbon monoxide concentration in the flue gas stream 124 may be obtained by a measuring device 160.
• the measuring device 160 may be any device capable of obtaining measurements of a carbon monoxide concentration. Examples of the measuring device 160 include, but are not limited to a sensor or a combustion gas analyzer, e.g. , a Fyrite® analyzer.
• the measuring device 160 may be coupled to a controller 170, e.g., a data processor, capable of accepting operating instructions 172 from a user and provide the user with data 174 concerning the measured concentration.
• the exhaust gas 158 is not returned to the air reactor 126 and is instead provided to the atmosphere.
• the carbon dioxide rich flue gas stream 124' is subjected to further processing prior to introduction to the processing unit 150.
• an oxidation catalyst 180 is placed downstream from the fuel reactor 128 at a location between the contaminant removal system 140 and the processing unit 150. The oxidation catalyst 180 facilitates the oxidation of carbon monoxide present in the carbon dioxide rich flue gas stream 124' to form carbon dioxide.
• the oxidation catalyst 180 works in conjunction with the air stream 152 to oxidize the carbon monoxide present in the flue gas stream. If the carbon monoxide concentration in the flue gas stream 124 is less than about 3% by volume of the carbon dioxide concentration in the flue gas stream, the air stream 152 that is 2 % of the volume of the flue gas stream should be sufficient for oxidation. However, if the volume of air stream 152 is less than 2 % of the flue gas stream 124, or the carbon monoxide concentration is 3 % by volume or greater, additional oxygen maybe added for oxidation purposes.
• an oxygen producing unit such as an air separator, may provide an oxygen stream 182 to increase the oxidation of the carbon monoxide.
• Oxidation of carbon monoxide present in the flue gas stream 124 allows the exhaust gas 158 to either be reused within the flue gas processing system 100 or contain concentrations of contaminants that are acceptable in release to the atmosphere.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Environmental & Geological Engineering (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Analytical Chemistry (AREA)
• Biomedical Technology (AREA)
• Health & Medical Sciences (AREA)
• Carbon And Carbon Compounds (AREA)
• Treating Waste Gases (AREA)
• Incineration Of Waste (AREA)
• Separation By Low-Temperature Treatments (AREA)
• Chimneys And Flues (AREA)
• Exhaust Gas Treatment By Means Of Catalyst (AREA)

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• 2010
  • 2010-03-11 US US12/721,638 patent/US8486361B2/en active Active
• 2011
  • 2011-03-01 WO PCT/IB2011/000423 patent/WO2011110915A1/en not_active Ceased
  • 2011-03-01 CN CN201180023351.9A patent/CN102883996B/zh active Active
  • 2011-03-01 CA CA2792730A patent/CA2792730C/en not_active Expired - Fee Related
  • 2011-03-01 AU AU2011225795A patent/AU2011225795B2/en not_active Ceased
  • 2011-03-01 EP EP11715029.2A patent/EP2544998B1/en active Active
  • 2011-03-01 PL PL11715029.2T patent/PL2544998T3/pl unknown
  • 2011-03-01 JP JP2012556600A patent/JP5746229B2/ja active Active

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