Search Results

A study was conducted to examine the effect of gasoline sulphur content, catalyst variables and driving characteristics on the formation of hydrogen sulphide in catalyst cars drawn from the 1990-91 European fleet. The work was based on chassis dynamometer experiments involving continuous analysis of hydrogen sulphide in raw exhaust gas downstream from the catalyst. A preconditioning procedure was devised that allowed storage of sulphur on the catalyst in a consistent way. The experimental driving (test) cycle provided for wide variation of catalyst temperature and of driving conditions (idle, acceleration, cruise, deceleration). Supplementary time-resolved measurements of carbon monoxide, total hydrocarbon, pre- and post-catalyst gas temperatures and AFR (air-to-fuel ratio) were made as a function of the driving cycle. Using this overall approach, it was possible to determine the important mechanistic factors promoting H2S formation, which was seen to occur in well-defined peaks.