When methanol is used as fuel, a hazardous unburned methanol, aldehyde, is exhausted. To solve this, a low heat rejection engine with an ATAC (active thermo-atmosphere combustion) system was adopted. By using a ceramic combustion chamber, the surface temperature of the combustion chamber is kept at high temperatures of 200 to 250 K. The characteristics of the combustion process and emissions from the ceramic methanol-fueled ATAC engine are examined. widening of the ATAC operation region with the use of methanol, and reduction of Formaldehyde emission due to the adoption of the ceramic combustion chamber are achieved experimentally. When the temperature of the combustion chamber wall becomes high, the thermal efficiency is reduced because the ignition timing is too early in ATAC operation. Supplying a lean fuel mixture to the engine yields a good result in both exhaust emissions and fuel consumption.
