硫含量对汽车尾气催化转化器耐久性的影响

Influence of sulfur content on the durability of automotive catalytic converters

汽车尾气催化转化器可用于控制汽车污染排放。该文考察了汽油硫含量对催化转化器耐久性能的影响。根据催化器机理,将热老化与化学老化分开进行试验。采用满足国Ⅲ和国Ⅳ、含硫质量分数量为150×10-6和50×10-6的两种汽油;利用发动机台架和R-FOCAS燃烧器模拟系统,对催化转化器进行了10万km耐久性试验,测量了催化转化器在试验前、后的起燃温度、储氧量等。结果表明:与化学老化影响相比较,热老化对催化转化器的影响更大;对于含硫质量分数150×10-6分数的汽油,通过高温脱硫过程,可适当恢复硫老化对催化转化器所造成的影响。

This paper studies the impact of the gasoline sulfur content on the durability of vehicle exhaust catalytic converters which can be used to reduce vehicle emission. Thermal aging test and chemical aging test were made separately based on the mechanism of catalytic converters. Engine bench tests were made with an R-FOCUS burner simulation system to evaluate converter durability for 1×10^-5 km using two kinds of fuels with one with sulfur content of 150 μg/g and the other with sulfur content of 50 μg/g, which meet China standards Ⅲ and Ⅳ. The ignition temperatures and oxygen storage capacities of the catalytic converters were measured before and after each test. The results show that the thermal aging has greater impact on the catalytic converters compared with the chemical aging and that high temperature desulfurization process can properly recover the catalytic converter poisoned by sulfur for fuel with sulfur content of 150×10^-8.