Exhaust gas treatment device and exhaust gas treatment method

An exhaust gas treatment device comprising:

• a first exhaust gas flow path where a first combustion exhaust gas discharged from a first power generation facility flows through;
• a second exhaust gas flow path where a second combustion exhaust gas discharged from a second power generation facility flows through;
• an exhaust gas exhaust flow path disposed by branching off from at least one of the first exhaust gas flow path and the second exhaust gas flow path, and configured to discharge an exhaust combustion exhaust gas, the exhaust combustion exhaust gas including at least a part of at least one of the first combustion exhaust gas flowing through the first exhaust gas flow path and the second combustion exhaust gas flowing through the second exhaust gas flow path;
• a nitrogen oxide removing unit configured to remove nitrogen oxide contained in an integrated combustion exhaust gas obtained by integrating the first combustion exhaust gas flowing through the first exhaust gas flow path with the second combustion exhaust gas flowing through the second exhaust gas flow path;
• an integrated waste heat recovery unit configured to recover waste heat from the integrated combustion exhaust gas with nitrogen oxide removed by the nitrogen oxide removing unit;
• and
• a CO2 recovery unit configured to recover CO2 contained in the integrated combustion exhaust gas by using CO2 absorbing liquid, the waste heat of the integrated combustion exhaust gas being recovered by the integrated waste heat recovery unit.