温度对乙醇氧化产生乙醛排放的影响

Influence of Temperature on Ethanol Oxidation to Acetaldehyde Emission

为了研究温度对乙醇氧化产生乙醛排放的影响,配置了乙醇标准气,并将流反应器置于发动机排气管中;在变温和恒温环境下,利用发动机排气温度环境和气相色谱氦离子化检测器的快速检测方法,研究了温度对乙醇氧化的影响.结果表明：乙醇起始氧化温度约为723 K,乙醛随着温度的升高呈现先增加后降低的趋势;变温环境下不同流速时乙醛生成和氧化的临界温度区间为832～870 K,在临界温度区间内乙醛的质量浓度最高;低于临界温度时乙醛的质量浓度随着温度的升高而提高;750～870 K为乙醛快速生成的温度区间,高于临界温度时乙醛的质量浓度随着温度的升高而降低.

The influences of temperature on ethanol oxidation to acetaldehyde emission are investigated in a flow reactor situated in the engine exhaust pipe. Unregulated emissions are detected by a gas chromatography with a pulsed discharge helium ionization detector. The experimental results show that the ethanol incipient oxidation temperature gets about 723 K. Acetaldehyde increases firstly and then decreases with increasing temperature. The critical temperature is limited within the range of 832-870 K in variable temperature environment, and acetaldehyde concentration reached maximum at the critical temperature. Below the critical temperature, acetaldehyde increases sharply with increasing temperature, and acetaldehyde generates quickly in temperature range of 750 K to the critical. And beyond the critical temperature, acetaldehyde emission decreases with increasing temperature.