Stable Combustion under Carbon Dioxide Enriched Methane blends for Exhaust Gas Recirculation (EGR)

Abstract

Exhaust gas recirculation (EGR) is one of the main techniques studied over the years to enable the use of oxyfuel combustion for carbon capture and storage (CCS). However, the use of recirculated streams with elevated carbon dioxide poses different challenges from the control of the flow rates and flue stream characteristics to the suppression of unwanted instabilities during the combustion process. Therefore, this study evaluates the use of various CO2 enriched methane blends and their response towards the formation of a great variety of structures that appear in swirling flows, which are the main mechanism for combustion control in current gas turbines systems. The study uses a 100kW acoustically excited swirlstabilised burner to investigate the flow field response. The results showed improved thermal efficiency of the system with high swirl and forcing while the blend of CO2 with methane balanced the heat release fluctuation with a corresponding reduction in the acoustic amplitudes of the system for a smooth running, suggesting that certain CO2 concentrations in the fuel can provide more stable flames at a certain carbon dioxide concentration.

A Numerical Study of CO2 Decoupled Effects on Extinction Limit and Flame Microstructure in CH4/Air Counterflow Diffusion Flame with Various Pressures

“…Low CO 2 emission to the environment gains more and more concern in the process of the inevitable energy revolution. Various advanced combustion technologies were proposed to meet the low CO 2 emission, among which the Exhaust Gas Recirculation (EGR) technology [1] can not only lower CO 2 emission, make contribution to CO 2 capture and sequestration (CCS) but also reduce the generation of nitrogen oxide pollution. Higher CO 2 concen-tration with EGR technology in the combustion zone is clearly distinguished from conventional combustion technology.…”