Combustor concept for industrial gas turbines with single digit NOx and CO emission values

Natural gas, when compared to other solid, liquid or gaseous fuels, offers a cleaner and more environmentally friendly combustion. Nevertheless, it also produces unwanted pollutant species such as nitrogen oxides (NOx) and carbon monoxide (CO) when fired in combustors of industrial gas turbines under high temperature and pressure. These emissions of NOx and CO are harmful for human and nature and need to be kept below the regulatory limits. This problem has been the subject of numerous research and development activities for decades. The current state of the art provides well-developed firing systems for industrial gas turbines, which ensure NOx and CO emission levels well below the legal limits [1 - 5]. A comprehensive overview of the characteristics currently available gas turbines on the German market is offered by the revised version of the ASUE brochure from 2015 in [6], where beyond the reference list about industrial and municipal gas turbines, NOx reduction methods and achieved NOx emission values are recorded. Nevertheless, there still is the need for additional research in order to contribute to both the simplification of the still complicated design of the overall combustor concepts and the further reduction of harmful emissions.