Systems and methods for power generation with carbon dioxide isolation

A power generation system comprising:

• a first turbine system comprising:
• a first compressor section comprising at least two stages, said at least two stages comprising a first low pressure compressor fluidly coupled to a first high pressure compressor, said first low pressure compressor configured to supply a first portion of compressed oxidant and said high pressure compressor is configured to supply a first compressed mixed stream;
• a first combustion chamber configured to combust a first fuel stream comprising carbon-based fuels and said first compressed mixed stream and to generate a first hot flue gas;
• and
• a first expander section having an inlet for receiving said first hot flue gas comprising at least two stages, said at least two stages comprising a first high pressure expander, said first high pressure expander fluidly coupled to a first low pressure expander configured to generate a first final exhaust and electrical energy;
• and
• a second turbine system comprising:
• a second compressor section comprising at least two stages, said at least two stages comprising a second low pressure compressor fluidly coupled to a second high pressure compressor, wherein said low pressure compressor is configured to generate a split stream and said high pressure compressor is configured to generate a second mixed stream;
• a second combustion chamber configured to combust said second mixed stream and a second fuel stream comprising carbon-based fuels and to generate a second hot flue gas;
• and
• a second expander section configured to receive said second hot flue gas and to generate a second final exhaust and electrical energy;
• and
• a CO2 separation system fluidly coupled to said first and second compressor sections, said CO2 separation system configured to receive said split stream and generate a CO2 lean stream;
• wherein said second compressor section is configured to receive said second final exhaust comprising carbon dioxide and to discharge said second mixed stream from said high pressure compressor to said second combustion chamber.

A method for generating power comprising:

• compressing an oxidant in a compressor section to produce a first portion and a second portion of compressed oxidant;
• combusting a first fuel and said first portion of compressed oxidant to produce a hot flue gas;
• expanding said hot flue gas in an expander section and generating electrical energy wherein said expander section is configured to receive said hot flue gas comprising at least two stages, the at least two stages comprising a high pressure expander configured to generate a first expanded exhaust gas rich in CO2, said high pressure expander fluidly coupled to a low pressure expander configured to generate a first final exhaust and said electrical energy;
• separating CO2 from said first expanded exhaust gas in a CO2 separator and introducing a CO2 lean gas to said low pressure expander;
• compressing said second portion of compressed oxidant in a compressor section comprising at least two stages, said at least two stages comprising a second low pressure compressor fluidly coupled to a second high pressure compressor, wherein said high pressure compressor is configured to receive said second portion of compressed oxidant;
• combusting a second fuel stream and a recycle stream comprising carbon-based fuels and generating a second hot flue gas;
• and
• expanding said second hot flue gas and generating a second final exhaust and electrical energy;
• wherein said second compressor section is configured to receive said second final exhaust comprising carbon dioxide and to discharge said recycle stream from said second high pressure compressor and a split stream from said second low pressure compressor to said first high pressure compressor.