As the most abundantnon-renewableenergy source available, coal has traditionallyplayed a major role in ensuringthe securityof energy,and will continueto playa key role in the world energy mix. The burning of coal has however always been a subject of environmental concern. In recent years, the emission of green house gases and global climate change has emerged as the largest environmental challenge. As coal fired power plants are categorised among the least carbon efficient energy producer in terms of CO 2
emission per unit of electricity generated, an immediate technological response is anticipated. Although, improving the efficiency of coal fired plants can decreaseCO2 emissions to some extent,fossil fuel based carboncaptureand storagetechnologies will have to bear the significant share in power generation, if reduction or even stabilisation of CO2 emissionis to be envisaged.
One promising technology with a potential for near complete capture of CO2 is the oxy-coal combustion process with flue gas recirculation. This technology is however still at an early stage of development, and until now there are no full-scale commercial plants based on this technology. The combustion of coal in this process takes place with almost pure oxygen and recycled flue gas resulting in a flue gas stream ofalmost pure C02, ready for geosequestration. The flue gas is recycled back into the fumace to control the temperature and maintain the heat flux profiles within the fumace. Research efforts are in progress for a better understanding of the oxy-coal combustion process. However, many issues still need to be addressed in order to obtain improved fundamental understandings.
The primary objective of this study is therefore, a comprehensive and well-planned experimental investigation to further understand the emission and combustion behaviour during 02/C02 combustion using aseries offuels, and is sub-divided into:
I. Determination of combustion and emission behaviour during un-staged combustion.
II. Determination ofNf), reduction potential during oxidant staged combustion.
III. Determination ofthe fate ofrecycled NO.
IV. Determination ofthe fate of802 and its impact on oxy-coal combustion.