Gas Turbine/Reciprocating Internal Combustion Engine Integrated System for Fuel-Flexible, High Efficiency and Low Emissions Power Generation

This paper reviews the technical approach and reports on the results of ASPEN Plus® modeling of two patented approaches for integrating a gas turbine with reciprocating internal combustion engine for lower emissions and higher efficiency power generation. In one approach, a partial oxidation gas turbine (POGT) is located in the 1st stage, and the H2-rich fuel gas from POGT exhaust is cooled and fed as main fuel to the second stage, ICE. In this case, the ICE operates in lean combustion mode. In the second approach, an ICE operates in partial oxidation mode (POX) in the 1st stage. The exhaust from the POX-ICE (a low BTU fuel gas) is combusted to drive a conventional GT in the 2nd stage of the integrated system. In both versions, use of staged reheat combustion leads to predictions of higher efficiency and lower emissions compared to independently providing the same amount of fuel to separate GT and ICE where both are configured for lean combustion. The POGT and GT analyzed in the integrated systems are based upon building them from commercially available turbocharger components (turbo-compressor and turbo-expander). Modeling results with assumptions predicting 50–52% LHV fuel to power system efficiency and supporting NOx < 9 ppm for gaseous fuels are presented for these GT-ICE integrated systems.