流化床燃烧石油焦N_2O排放特性

通过在一小型流化床试验台上进行石油焦的燃烧试验 ,阐述了N2 O和NO形成与分解机理 ,模拟研究了N2 O的排放特性 .采用不同程度脱去挥发分的石油焦颗粒 ,研究脱挥发分的程度对N2 O形成的影响 ,脱挥发分的温度越高 ,即脱挥发分的程度越高 ,石油焦氮形成N2 O的量越少 ,这表明石油焦挥发分氮形成N2 O量高于相应石油焦焦炭氮燃烧产生的N2 O量 .燃料燃烧过程中 ,NO形成比较均匀 ,而N2 O形成比较复杂 ,燃料氮向NO的转化率随脱挥发分温度升高而增加 ,而向N2 O的转化率则有一临界脱挥发分温度点 .

N2O FORMATION AND REDUCTION IN FLUIDIZED BED COMBUSTION OF PETROLEUM COKE

N 2O emission from petroleum coke under fluidized bed combustion (FBC) condition is investigated in this paper. Nitrous oxide formation and reduction mechanisms are studied in a bench scale FBC. In order to investigate the effect of the partial devolatilization on N 2O and NO emissions, the petroleum coke char prepared at various devolatilization temperatures is burnt. N 2O emission is strongly dependent on the devolatilization temperature. The petroleum coke char devolatilized at a higher temperature shows the lower N 2O formation. The fuel-N conversion ratio to N 2O is increasing with an increase in burning temperature, while the one to NO is decreasing. The results show that there is an optimum range of devolatilizing temperature that gives a maximum conversion to N 2O, and nitrogenous species in the char during burning are largely converted to N 2O. The contribution of volatile to N 2O is larger than that of char.