System for chemically absorbing carbon dioxide in combustion exhaust gas

A carbon dioxide (CO2) chemical absorption system comprising:

• a CO2 absorption column for separating CO2 from combustion exhaust gas by absorbing the CO2 in the combustion exhaust gas with a CO2 absorbing liquid mainly composed of an aqueous alkanolamine solution;
• a regeneration column for regenerating the CO2 absorbing liquid by desorbing CO2 gas from the CO2 absorbing liquid that has absorbed CO2;
• a condenser for condensing water vapor entrained in the desorbed CO2 gas discharged from the top of the regeneration column, thereby obtaining reflux water;
• a pipe for returning a part of the reflux water obtained by the condenser to the top of the regeneration column, and dispersing the reflux water in the regeneration column;
• a means for measuring the temperature of an upper portion of a packed bed in the regeneration column, and controlling the flow rate of the reflux water dispersed in the regeneration column so that the temperature is a predetermined value;
• a pipe for sending the regenerated CO2 absorbing liquid from the bottom of the regeneration column to the top of the absorption column;
• and
• a pipe for joining the remaining reflux water obtained by the condenser into the pipe for sending the regenerated CO2 absorbing liquid.

A method of carbon dioxide (CO2) chemical absorption comprising the steps of:

• separating CO2 from combustion exhaust gas by absorbing the CO2 in the combustion exhaust gas with a CO2 absorbing liquid mainly composed of an aqueous alkanolamine solution;
• regenerating the CO2 absorbing liquid by desorbing CO2 gas from the CO2 absorbing liquid that has absorbed CO2;
• condensing water vapor entrained in the desorbed CO2 gas, thereby obtaining reflux water;
• dispersing all or part of the reflux water obtained by the condensation step to the CO2 gas desorbed in the regeneration step to cool the CO2 gas and remove absorbing liquid mist entrained in the CO2 gas;
• collecting the dispersed reflux water to prevent the dispersed reflux from being involved in the regeneration step;
• and
• mixing the collected reflux water with the regenerated CO2 absorbing liquid.

A method of carbon dioxide (CO2) chemical absorption comprising the steps of:

• separating CO2 from combustion exhaust gas by absorbing the CO2 in the combustion exhaust gas with a CO2 absorbing liquid mainly composed of an aqueous alkanolamine solution;
• regenerating the CO2 absorbing liquid by desorbing CO2 gas from the CO2 absorbing liquid that has absorbed CO2;
• condensing water vapor entrained in the desorbed CO2 gas, thereby obtaining reflux water;
• dispersing a part of the reflux water obtained by the condensation step to the CO2 gas desorbed in the regeneration step to cool the CO2 gas and remove absorbing liquid mist entrained in the CO2 gas;
• measuring the temperature of the CO2 gas desorbed in the regeneration step, and controlling the flow rate of the dispersed reflux water so that the temperature is a predetermined value;
• and
• mixing the remaining reflux water obtained by the condensation step with the regenerated CO2 absorbing liquid.