Combustion characteristics of coal in a mixture of oxygen and recycled flue gas

Abstract

The combustion of coal in a mixture of pure O 2 and recycled flue gas is one variant of a novel combustion approach called oxy-fuel combustion. With the absence of N 2, this approach leads to a flue gas stream highly enriched in CO 2. For many applications, this flue gas stream can then be compressed and sequestered without further separation. As a result, oxy-fuel combustion is an attractive way to capture CO 2 produced from fossil fuel combustion. When coal is burned in this O 2 and CO 2 rich environment, its combustion characteristics can be very different from conventional air-fired combustion. In CETC-O, a vertical combustor research facility has been used in the past years to investigate the combustion characteristics of several different coals with this variant of oxy-fuel combustion. This included flame stability, emissions of NO x , SO x and trace elements, heat transfer, in-furnace flame profiles and flue gas compositions. This paper will report some of the major findings obtained from these research activities.