Rice husk is one of the most important agricultural residues in Egypt. The
present study introduces an experimental investigation on circulating
fluidized bed (CFB) combustion of rice husk and co-combustion of rice
husk and Egyptian (Sinai) coal. The test rig is a pilot scale CFB
combustor of 145 mm inner diameter, 2 m tall and 100 kW thermal
capacity. The influences of excess air, and coal share were studied.
Temperature and heat flux along the reactor height, in addition to the
concentrations of CO, NOx and SO2 in the flue gas out from cyclone were
measured. The combustion efficiency was estimated based on CO and
unburned char in flue gas. The highest efficiency recorded for rice husk
combustion was 98% at excess air ratio (EA) = 1.1 and secondary air ratio
(SAR) = 50%. Co-combustion of Sinai coal and rice husk reduced CO but
increased SO2 and NOx emissions. The results suggest that rice husk is
potential fuel that can be utilized for efficient and renewable energy
production by using CFB combustion system especially at co-combustion
with coal.