Gas turbine related technologies for carbon capture

Abstract

Combustion modes in gas turbines are evolving in order to meet requirements related to lower emissions and greater thermodynamic efficiency. Such demands can be contradictory and the additional complication of fuel flexibility comes to the fore with potential new fuel stream opportunities arising. The latter may include hydrogen and carbon monoxide rich streams as well as blends with significant amounts of carbon dioxide arising from certain types of syngas (e.g. bio-derived). The matter is further complicated by the impact of combustion stability related issues that arise in the context of the ubiquitous transition to lean pre-vapourised premixed (LPP) combustion for power generation applications. Post-combustion carbon capture is generally considered the leading candidate in the context of LPP based technologies. Significant capture related issues arise in terms of parasitic losses associated with CO 2 separation and transportation technologies (e.g. compression). The former is typically the major contributor and the relatively low concentration of CO 2 in flue gases, combined with excess oxygen resulting from LPP based operation, does impact separation technologies. It hence appears natural to consider the operating mode of the gas turbine and the impact of the fuel composition on the flue gas characteristics alongside the development of efficient and novel separation technologies.