Oxy-fuel power generation and optional carbon dioxide sequestration

A turbine system comprising an oxy-fuel gas turbine generator comprising a combustion chamber section and an expander turbine section, a pumped liquid oxygen feed connected to the combustion chamber, a pumped liquid fuel feed connected to the combustion chamber, and a steam feed connected to the combustion chamber, wherein oxygen and fuel are injected into and combusted in the combustion chamber in the presence of steam, and exhaust fluids from the combustion chamber are expanded through the expander turbine section to drive an electrical generator, wherein water and/or steam from the exhaust fluids from the expander turbine section is separated and recirculated as steam to the steam feed of the combustion chamber by way of an integrated recuperator and separator comprising:

• an evaporator heat exchanger having an exhaust fluid inlet connected to an exhaust fluid outlet of the oxy-fuel gas turbine generator and an exhaust fluid outlet, and a water inlet and a steam outlet connected to the steam feed of the combustion chamber;
• an economiser heat exchanger having an exhaust fluid inlet connected to the exhaust fluid outlet of the evaporator heat exchanger and an exhaust fluid outlet, and a water inlet and a water outlet, the water outlet being connected to the water inlet of the evaporator heat exchanger;
• a first stage condenser having an exhaust fluid inlet connected to the exhaust fluid outlet of the economiser heat exchanger and an exhaust fluid outlet, and a cooling water inlet and a cooling water outlet;
• and a second stage condenser and separator having an exhaust fluid inlet connected to the exhaust fluid outlet of the first stage condenser, a separated carbon dioxide outlet, a separated water outlet connected to the water inlet of the economiser heat exchanger, a cooling water inlet and a cooling water outlet, the cooling water outlet connected to the cooling water inlet of the first stage condenser.

A method of separating carbon dioxide from water in turbine exhaust fluids, wherein:

• i) the turbine exhaust fluids are passed through an evaporator heat exchanger having an exhaust fluid inlet and an exhaust fluid outlet, and a water inlet and a steam outlet;
• ii) the turbine exhaust fluids are then passed through an economiser heat exchanger having an exhaust fluid inlet connected to the exhaust fluid outlet of the evaporator heat exchanger and an exhaust fluid outlet, and a water inlet and a water outlet, the water outlet being connected to the water inlet of the evaporator heat exchanger;
• iii) the turbine exhaust fluids are then passed through a first stage condenser having an exhaust fluid inlet connected to the exhaust fluid outlet of the economiser heat exchanger and an exhaust fluid outlet, and a cooling water inlet and a cooling water outlet;
• iv) the turbine exhaust fluids are then passed through a second stage condenser and separator having an exhaust fluid inlet connected to the exhaust fluid outlet of the first stage condenser, a separated carbon dioxide outlet, a separated water outlet connected to the water inlet of the economiser heat exchanger, a cooling water inlet and a cooling water outlet, the cooling water outlet connected to the cooling water inlet of the first stage condenser;
• and
• v) separated carbon dioxide is extracted by way of the separated carbon dioxide outlet.

A method of electrical power generation, wherein:

• i) liquid oxygen and liquid fuel are pumped to a predetermined pressure, vaporised and combusted in a combustion chamber of an oxy-fuel gas turbine generator in the presence of steam;
• ii) exhaust fluids from the combustion chamber are expanded through an expander turbine section of the oxy-fuel gas turbine generator so as to drive an electrical generator;
• and
• iii) water from exhaust fluids from the oxy-fuel gas turbine generator is separated and recirculated as steam to the combustion chamber.