生物柴油抑制多环芳香烃生成的机理分析

摘要

The detailed chemical kinetic mechanism of biodiesel PAH formation was determined and the influences of biodiesel on incomplete combustion products PAHs ,gas-phase precursors C2 H2 and C3 H3 ,free radicals O and OH and low-temperature products CO and CO2 were simulated with the shock tube model of CHEMKIN-PRO software .The results show that the con-centration of free radicals O and OH increase and more C2 H2 and C3 H3 are oxidized into CO2 with the increase of biodiesel vol-ume fraction .In addition ,the non-carbonyl O in the methyl ester radical makes more carbon atoms convert into CO 2 via OCHO and CH3 OCO decomposition in low-temperature period so that the C2 H2 and C3 H3 decrease ,thus suppresses PAHs formation.%建立了生物柴油PAHs生成的详细化学反应动力学机理，利用Chemkin-Pro软件中的反射激波管模型，模拟了生物柴油对混合燃料燃烧时多环芳烃PAHs ，气相前驱物C2 H2，C3 H3，自由基O ，OH以及低温CO ，CO2生成的影响。模拟结果表明：随着生物柴油体积分数的增加，O ，O H自由基峰值浓度增大，更多的C2 H2，C3 H3被氧化形成稳定的CO2；另外，生物柴油甲酯基中非羰基的氧使更多的碳原子在低温阶段通过OCHO以及CH3 OCO分解转化为CO2，导致C2 H2，C3 H3生成量减小，抑制了PAHs的生成。