Methanol as a Fuel for a Lean Turbocharged Spark ignition Engine

Lean turbocharged operation with methanol was characterized using a single-cylinder spark ignition engine. Efficiency, exhaust emissions, and combustion properties were measured over a range of air/fuel ratios at two naturally-aspirated and three turbocharged conditions.

When compared to stoichiometric, naturally-aspirated operation, the lean turbocharged conditions improved efficiency while reducing carbon monoxide and oxides of nitrogen emissions. However, unburned fuel and aldehyde emissions increased. If used in conjunction with an oxidizing catalyst and appropriate feedback controls, lean turbocharged operation has the potential of improving efficiency and exhaust emissions performance over a stoichiometric, three-way catalyst system.