Systems and Methods For Carbon Dioxide Captrue and Power Generation In Low Emission Turbine Systems

Abstract

Systems, methods, and apparatus are provided for generating power in low emission turbine systems and separating the exhaust into rich CO2 and lean CO2 streams. In one or more embodiments, the exhaust is separated at an elevated pressure, such as between a high-pressure expansion stage and a low-pressure expansion stage.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Application 61 / 542,036 filed Sep. 30, 2011 entitled, SYSTEMS AND METHODS FOR CARBON DIOXIDE CAPTURE IN LOW EMISSION TURBINE SYSTEMS; U.S. Provisional Application 61 / 466,384 filed Mar. 22, 2011 entitled, LOW EMISSION TURBINE SYSTEMS HAVING A MAIN AIR COMPRESSOR OXIDANT CONTROL APPARATUS AND METHODS RELATED THERETO; U.S. Provisional Application 61 / 542,030 filed Sep. 30, 2011 entitled, LOW EMISSION TURBINE SYSTEMS INCORPORATING INLET COMPRESSOR OXIDANT CONTROL APPARATUS AND METHODS RELATED THERETO; U.S. Provisional Application 61 / 466,385 filed Mar. 22, 2011 entitled, METHODS FOR CONTROLLING STOICHIOMETRIC COMBUSTION ON A FIXED GEOMETRY GAS TURBINE SYSTEM AND APPARATUS AND SYSTEMS RELATED THERETO; U.S. Provisional Application 61 / 542,031 filed Sep. 30, 2011 entitled, SYSTEMS AND METHODS FOR CONTROLLING STOICHIOMETRIC COMBUSTION IN LOW EMISSION TURBINE SYSTEMS; U.S. Provisional Application 61...

AI Technical Summary

Benefits of technology

The invention describes a system and method for generating power from high pressure exhaust gases of a gas turbine with low emissions. The exhaust gases are first expanded at high pressure in an expander and separated into two streams - one rich in CO2 and one lean. The lean stream is then further expanded at low pressure in a second expander to extract energy from it. By doing this, the separation equipment can be downsized and the efficiency of the separation process can be improved.

Problems solved by technology

However, both of these solutions are expensive and reduce power generation efficiency, resulting in lower power production, increased fuel demand and increased cost of electricity to meet domestic power demand.

In particular, the presence of oxygen, SOX, and NOx components makes the use of amine solvent absorption very problematic.

However, there are no commercially available gas turbines that can operate in such a cycle and the power required to produce high purity oxygen significantly reduces the overall efficiency of the process.

Capturing carbon dioxide from the exhaust of a gas turbine power plant is expensive for the following reasons: (a) the concentration of carbon dioxide in the exhaust stack is low, (b) the volume of gas that needs to be treated is large, (c) the pressure of the exhaust stream is low, and (d) the amount of oxygen present in the exhaust stream is large.

All of these factors result in a high cost of carbon dioxide capture.

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