Basic Aspects of Combustion Stability and Pollutant Emissions of a CO₂ Decomposition-Based Power-Generation Cycle

Results are reported on an investigation of the technical feasibility of separating and decomposing CO 2 within the context of power/energy-generation. The power/energy-generation environment is well-suited for such an application because it provides the high-temperature conditions and/or electric energy needed. The emphasis in this paper is on the combustion aspects of this integrated CO 2 -capture/power-generation advanced cycle. As part of this effort, experimental and numerical studies were carried out on the dynamics and structure of lean atmospheric CH 4 /air flames in the presence of binary CO/CO 2 mixtures that would result from the CO 2 decomposition process. For the lean flames that were considered in this investigation, application of the integrated CO 2 -capture/power-generation advanced cycle was found to provide important benefits in terms of both flame stability and flame intensity for a range of conditions, in addition to allowing for waste heat utilization. For another range of conditions, significant improvements in pollutant emissions were identified. Generally, improvements in combustion intensity and stability can be achieved but at a cost of increased NO x emissions, and vice versa. A range of conditions also exists for which the cycle allows for effective waste heat utilization without an undue impact on combustion stability and pollutant emissions.