Abstract
Fossil fuel combustion generates large amount of green house gas and it was considered major emission source causing global warming. For reducing green house gas, renewable energy resources have been emerged as an alternative energy. Among those resources, waste has been considered major resource as one of renewable energy, but it has been not utilized sufficiently. In Korea, there are lots of efforts to utilize sewage sludge as one of renewable energy resources due to waste to energy project of government. In this paper, sewage sludge was utilized as a fuel in order to recover heat energy source with CO2
reduction using oxy-fuel combustion in 30KWth circulating fluidized bed (CFB) pilot plant.
The oxygen concentration increased, excess air ratio increased. Since it is caused by cooling combustion in the top of combustion zone. Pressure gradients increase in proportion to volume of input gas per moles. Therefore, Oxy-21~25% is suitable to sludge oxy-fuel combustion. The recirculation of solid has been made properly, and moisture contents a little increase in oxy-fuel combustion. Combustion efficiency is the highest at Oxy-25%. NOx and SOx emission is affected by temperature. In case of cooling combustion, NOx emissions are increased, SOx emissions are decreased.
