Current status and experimental investigation of oxy-fired fluidized bed

Oxy-fired fluidized bed combustion technique combines the advantages of both the fluidized bed combustion and oxy-fired technology. In oxy-fired condition, a mixture of oxygen with CO2 or recycled flue gas (RFG) is used for the combustion. This paper is divided into two parts; First part covers a technical review of the oxy-fired fluidized bed units, including the studies performed on bubbling fluidized bed, circulating fluidized bed and pressurized fluidized bed. Work presented, identifies and illustrates the trends and challenges related to oxy-fired fluidized bed in the current scenario. It is found that it would take many years to utilize the benefit of this technology fully. The second part explores the possibility of this technology for co-firing cases. Rice husk (RH), plant litter (PL), and coal are co-fired inside a 20 kW lab scale bubbling fluidized bed combustor under O2/N2/RFG mode. The experimental results show that the blends of coal-PL and coal-RH have been burnt successfully. Carbon dioxide is increased found as a result of increasing oxygen. The measured percentage of NOx and other gasses are found within permissible limit.