Mitsubishi Jukogyo Kabushiki Kaisha

The Kansai Electric Power Co., Inc.

Other

Mutsunori Karasaki

Masaki Iijima

Shigeaki Mitsuoka

Shigeru Shimojo

Kunihiko Yoshida

Taiichiro Suda

Masumi Fujii

Yoshitsugu Hotta

Tomio Mimura

Kenji Kobayashi

Touru Seto

Toru Seto

Masami Kawasaki

Fumio Tomikawa

Yukihiro Jinno

Koichi Kitamura

Kouichi Kitamura

Touro Seto

A process for removing CO from a combustion gas which comprises bringing a combustion gas containing oxygen and CO and a CO absorbent solution into contact at the atmospheric pressure, thereby allowing the CO absorbent solution to absorb CO from the combustion gas, and, in the ensuing step, heating the absorbent solution that has absorbed CO to liberate CO and regenerate the CO absorbent solution, and circulating the regenerated solution for reuse. An aqueous solution of a hindered amine selected from the group consisting of 2-amino-2-methyl-1-propanol (AMP), 2-(ethylamino)-ethanol (EAE), 2-(methylamino)-ethanol (MAE), and 2-(diethylamino)-ethanol (DEAE) is used as the CO absorbent solution, and carbon steel is used in building the members of the equipment that contact the aqueous hindered amine solution. The absorbent solution contains cupric carbonate which is a corrosion inhibitor.

Process for removing carbon dioxide from combustion gases

There are disclosed a method for removing CO from a combustion exhaust gas which comprises the step of bringing the combustion exhaust gas under atmospheric pressure into contact with an aqueous solution of a hindered amine selected from the group consisting of 2-amino-2-methyl-1-propanol, 2-methylaminoethanol, 2-ethylamino-ethanol and 2-piperidineethanol; and another method for removing carbon dioxide from a combustion exhaust gas which comprises the step of bringing the combustion exhaust gas under atmospheric pressure into contact with a mixed aqueous solution of 100 parts by weight of an amine compound (X) selected from the group consisting of 2-amino-2-methyl-1, 3-propanediol, 2-amino-2-methyl-1-propanol, 2-amino-2-ethyl-1, 3-propanediol, t-butyldiethanolamine and 2-amino-2-hydroxymethyl-1,3-propanediol; and 1-25 parts by weight of an amine compound (Y) selected from the group consisting of piperazine, piperidine, morpholine, glycine, 2-methylamino-ethanol, 2-piperidineethanol and 2-ethylaminoethanol.

Method for removing carbon dioxide from combustion exhaust gas

A process is provided for removing carbon dioxide out of combustion exhaust gas by scrubbing the exhaust gas with an aqueous solution of monoethanolamine in a scrubber, and regenerating the carbon dioxide-loaded aqueous solution of monoethanolamine in a regenerator. The process is provided with means for replenishing the aqueous solution of monoethanolamine with a stock, aqueous solution containing from about 70% to about 75% by weight of monoethanolamine. By providing a stock, aqueous solution containing from about 70% to about 75% by weight of monoethanolamine, which is injected into the carbon dioxide-loaded aqueous solution of monoethanolamine being transferred from the scrubber to the regenerator, the entire carbon dioxide recovery system is free from flammables, rendering fire-fighting precautions unnecessary.

Recovery of carbon dioxide from combustion exhaust gas

There are disclosed a method for removing CO.sub.2 from a combustion exhaust gas which comprises the step of bringing the combustion exhaust gas under atmospheric pressure into contact with an aqueous solution of a hindered amine selected from the group consisting of 2-amino-2-methyl-1-propanol, 2-methylaminoethanol, 2-ethylaminoethanol and 2-piperidineethanol; and another method for removing carbon dioxide from a combustion exhaust gas which comprises the step of bringing the combustion exhaust gas under atmospheric pressure into contact with a mixed aqueous solution of 100 parts by weight of an amine compound (X) selected from the group consisting of 2-amino-2-methyl-1,3-propanediol, 2-amino-2-methyl-1-propanol, 2-amino-2-ethyl-1,3-propanediol, t-butyldiethanolamine and 2-amino-2-hydroxymethyl-1,3-propanediol; and 1-25 parts by weight of an amine compound (Y) selected from the group consisting of piperazine, piperidine, morpholine, glycine, 2-methylaminoethanol, 2-piperidineethanol and 2-ethylaminoethanol.

A process for removing CO.sub.2 from a combustion gas which comprises removing CO.sub.2 from the combustion gas through contact of an aqueous hindered amine solution used as a CO.sub.2 absorbent solution with the combustion gas at atmospheric pressure and then, in a regeneration column, liberating CO.sub.2 from the absorbent solution that has absorbed CO.sub.2 by heating it and thereby regenerating the absorbent solution. The process further comprises a partial absorbent solution regeneration step in at least one stage wherein the absorbent solution that has absorbed CO.sub.2 is heated through heat exchange with a high-temperature regenerated absorbent solution and part of the CO.sub.2 that is liberated is separated from the absorbent solution. Following this, according to the necessity, part of the partially regenerated absorbent solution thus obtained is returned to the step of removing CO.sub.2 from the combustion gas for use as part of the CO.sub.2 absorbent solution while the rest or all of the absorbent solution is heated and fed to a regeneration column further to liberate CO.sub.2 and regenerate the absorbent solution.

An apparatus for gas-liquid contact in which tubular structure fillers having a cross section of any of various shapes and having straight tubular portions are arranged in a substantially vertical direction in the form of plural steps so that the gas-liquid contact surfaces of the fillers may be parallel with the flow of the gas, the apparatus for gas-liquid contact being characterized in that the gas-liquid contact surfaces comprise rough surface portions, porous surface portions, meshes or plates to which meshes adhere, or there is interposed, between the plural steps of the fillers, a dispersing plate for receiving the liquid downward coming from the site above the fillers, dispersing the liquid, and allowing the liquid to downward flow.

Apparatus for gas-liquid contact

A method for recovering carbon dioxide by absorbing carbon dioxide present in a combustion exhaust gas using an aqueous alkanolamine solution, comprising the step of bringing a combustion exhaust gas from which carbon dioxide has been absorbed and removed into contact with water containing carbon dioxide. A method for treating a combustion exhaust gas for denitration using ammonia as a reducing agent and for removal of carbon dioxide by absorption with an aqueous alkanolamine solution, which method comprising the steps of recovering ammonia present in the combustion exhaust gas after the carbon dioxide removal, and using the recovered ammonia as a reducing agent for the denitration. A method for removing CO.sub.2 from a combustion exhaust gas comprising the step of bringing the combustion exhaust gas into contact under atmospheric pressure with an aqueous monoethanolamine solution having a concentration of 35% by weight or more.

Method for treating combustion exhaust gas

A process for removing carbon dioxide (CO.sub.2) from a combustion exhaust gas of a boiler (1) which generates steam for driving high (3), intermediate (7), and low (8) pressure turbines. The process comprises the steps of removing CO.sub.2 in the combustion exhaust gas by absorption with a CO.sub.2 -absorbing liquid (19), liquefying the removed CO.sub.2 (28) by compression (42) and cooling (48), storing (52) the CO.sub.2, and regenerating the CO.sub.2 -absorbing liquid by a CO.sub.2 -absorbing liquid regeneration column (24) equipped with a reboiler (30). In the process, a part (40) of steam discharged from the high pressure turbine (3) is used to drive turbines (41, 43) for compressors (42, 44) that compress the CO.sub.2, and a refrigerant for cooling the CO.sub.2, and steam (45) discharged from the compressor turbines is supplied as a heating source to the reboiler (30) for the regeneration of the CO.sub.2 -absorbing liquid. A decrease in the overall power plant efficiency due to the removal of carbon dioxide from the exhaust gas can be reduced.

Process for removing carbon dioxide from combustion exhaust gas

An electric generating power plant and a method of operation thereof wherein the boiler (1) produces steam to a turbine driven-generator (2), carbon dioxide from combustion exhaust gas emitted from the boiler is simultaneously absorbed in an absorbing solution in an absorber (7), the absorbing solution with the absorbed carbon dioxide is passed through a regenerator (10) where the carbon dioxide is stripped from the absorbing solution, the regenerated absorbing solution is returned to the absorber (7), and steam from either the boiler (1) or turbine of the turbine-driven generator (2) is supplied to a reboiler (13) to provide heat for operation of the regenerator (10). During periods of high demand for electric power steam extraction from the boiler or turbine is discontinued, operation of the regenerator (10) is discontinued and the absorbing solution from the absorber (7) is stored in a first storage unit (15). During periods of low power demand steam is supplied to the reboiler (13) from the boiler (1) or turbine and absorbing solution from the first storage unit (15) is fed to the regenerator (10) for operation thereof, and absorbing solution stripped of carbon dioxide from the regenerator (10) is stored in a second storage unit (16). Absorbing solution from the second storage unit (16) is fed to the absorber (7) during periods of high power demand.

An apparatus and a process for removing CO.sub.2 from a combustion exhaust gas, by effecting counterflow contact of aqueous alkanolamine solution with the combustion exhaust gas to absorb CO.sub.2 from the gas in the alkanolamine solution and effecting a further contact of the gas with either, condensate water formed by causing condensation of the gas after removal of CO.sub.2, or condensate water formed by causing condensation of the combustion exhaust gas directly after combustion of the fuel. The apparatus includes a tower (1), a first contact section (2) in the tower through which the exhaust gas flows upwardly in counterflow contact with the aqueous alkanolamine solution dispersed by a nozzle device (7) downstream of the first contact section (2), a second contact section (3) in the tower (1) downstream of the nozzle device (7) for effecting counterflow contact of reflux water from a spent absorbent liquor regenerating tower (28) with the gas after removal of CO.sub.2. The temperature of the aqueous alkanolamine solution to be supplied to the CO.sub.2 -removing tower (1) is adjusted in such a manner that the temperature of the exhaust gas at the entrance (4) of the CO.sub.2 -removing tower and that of the treated gas at the exit (5) of the CO.sub.2 -removing tower are the same.

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Tokyo, Japan

Mutsunori Karasaki