[Investigation on emission characteristics of methanol vehicle's aldehyde and ketone pollutants]

Investigation on the character and quantity of aldehydes and ketones emitted from methanol vehicle was implemented respectively by using high performance liquid chromatograph (HPLC) method. Experiments of vehicles equipped with and without three-way catalyst (TWC) under transient and steady mode were carried out. The emission results were compared with that of gasoline vehicle. The data showed that the efficiency of aldehydes and ketones emitted from methanol vehicle and gasoline vehicle were 22.53% and 48.95% with TWC under transient state respectively. When the vehicle is fueled with methanol, the main emissions are formaldehyde, acetaldehyde, acraldehyde + acetone, and these three matters account for 97.18% of the total emission. This proportion is 39.07% when the vehicle is fueled with gasoline. However, the total quantity of aldehydes and ketones from methanol vehicle without TWC was less than that from gasoline vehicle without TWC. Whether with or without TWC, aldehydes and ketones from methanol vehicle were more than that from gasoline vehicle under steady states. When the vehicle is fueled with methanol, the emission of aldehydes and ketones is on the top level at the speed of 60 km/h, and the converting efficiency is also the highest, which is 88.50%. When at the speed of 60 km/h, 90 km/h, 120 km/h, the formaldehyde quantity of methanol vehicle was 332.94%, 374.47% and 357.58% as much as that from gasoline vehicle respectively.