Catalytic Ignition of Methanol in a Diesel Engine with a Platinum-Coated Glow Plug

In recent years, intensive research has been pursued throughout the world in order to find substitutes to crude oil based fuel in compression-ignition engines. Among the different fuels studied, methanol is probably the primary candidate to substitute diesel fuel in the future. The major problems encountered with methanol in diesel engines are its poor cold startability together with unstable combustion levels under low load. Forced ignition techniques such as glow plugs and spark plugs have been used to overcome these problems. The major disadvantages with the use of glow plugs are their high power requirements as well as their limited lifetime.

This paper presents the results from recent work done on the feasibility of catalytically igniting methanol with the use of platinum and platinum/rhodium-coated glow plugs. The effect of the catalysts was determined from glow-plug surface temperature measurements, cylinder pressure analysis, and high-speed photography of the combustion chamber in a two-stroke D.I. diesel engine. The catalytic glow plugs consistently lowered glow-plug temperatures needed for stable combustion by approximately 300 deg C with respect to standard stainless steel glow plugs.