Process for removing carbon dioxide from combustion exhaust gas

A process for removing carbon dioxide (CO.sub.2) from a combustion exhaust gas of a boiler generating steam conducted to a first high pressure turbine, a second intermediate pressure turbine operating at a pressure lower than said first turbine, and a third low pressure turbine operating at a pressure lower than said second turbine for driving said turbines, comprising:

• removing CO.sub.2 in said combustion exhaust gas by absorbing said CO.sub.2 in a CO.sub.2 -absorbing liquid;
• providing a CO.sub.2 -absorbing liquid regeneration column having a reboiler;
• conducting said CO.sub.2 -absorbing liquid through said absorbing liquid regeneration column for regenerating said CO.sub.2 -absorbing liquid;
• providing a fourth turbine operatively connected to a first compressor for driving said first compressor thereby;
• providing a fifth turbine operatively connected to a second compressor for driving said second compressor thereby;
• conducting a part of steam discharged from said first turbine to said fourth and fifth turbines;
• driving said fourth and fifth turbines by said part of steam discharged from said first turbine;
• driving said first and second compressors by said fourth and fifth turbines, respectively;
• conducting said removed CO.sub.2 to said first compressor and compressing said removed CO.sub.2 therein;
• conducting said compressed CO.sub.2 from said first compressor to a cooler;
• passing a refrigerant through said second compressor and through said cooler for cooling and liquifying said compressed CO.sub.2 ;
• storing said liquified CO.sub.2 ;
• and
• conducting steam discharged from said first and second compressor turbines to said reboiler as a heating source for said reboiler for regeneration of said CO.sub.2 -absorbing liquid.