THE INFLUENCE OF GAS STAGING DURING OXY-FUEL COMBUSTION UNDER CFB CONDITIONS

摘要

The paper deals with the effect that associates with an inlet gas staging during coal combustion in O2/CO2 environment.The process is conducted in a small pilot-scale test rig with a circulating fluidized bed (CFB).The increase in a value of primary gas-to-secondary gas ratio (PG/SG) accelerates carbon conversion in a bottom part of combustion chamber.At the same time however, the decline in a fraction of CO is observed.Similarly, higher conversion ratios of combustible sulfur are noticed while the fraction of PG in an inlet gas increases.Moreover, the phenomenon of selfdesulfurization is found.The strong influence of gas staging on NO formation that proceeds in a bottom part of the combustion chamber is also noticed.Furthermore, the reduction of nitrogen oxides in an upper part of the furnace is observed.