Energy & Fuels, Vol.15, No.5, 1220-1224, 2001
Effect of batch feeding of limestone on NOx and SO2 emissions during petroleum coke combustion in a bubbling fluidized bed combustor
A kind of petroleum coke was burnt in a bubbling fluidized bed combustor (BFBC). The effect of limestone batch feed for SO2 removal on NOx emission was evaluated. NOx emission decreased with limestone feed but a difference in the pattern of the change in emissions was observed between NOx emission and SO2 emission; SO2 emission decreased immediately after limestone feed, whereas NOx emission decreased gradually. The bed material samples were taken from the BFBC after the experiments. The catalytic activity of bed materials for NOx formation and destruction was evaluated using a fixed bed reactor. A new explanation of NOx reduction after limestone feed during petroleum coke combustion was proposed; the decrease in NOx emission after limestone feed was mainly attributable to the deactivation of petroleum coke ash for NOx formation from volatile matter.