Methanol obtained from regenerative sources is a renewable fuel with many advantages when used in a spark ignition combustion process. Methanol has a comparatively high enthalpy of vaporization, leading to lower combustion temperatures (compared to gasoline combustion) and, hence, lower wall heat losses as well as a reduced tendency to autoignition. Several cold start methods were examined for this paper. In a serial hybrid powertrain with one internal combustion engine, ICE, and one electric machine, the load demand of the ICE can be controlled for best efficiency. The ICE is operated on liquid renewable fuel, which provides a high volumetric and gravimetric power density, easy energy storage, delivered from a very cost effective already existing infrastructure of fuel distribution. The electric machine provides comfortable electric driving, high efficiency, locally and temporary zero emissions. The eFuel should be produced from a closed carbon cycle.
Methanol is a challenging fuel, since it has a high flash point at 11 °C indicating a challenging cold start. Feasible solutions are fuel or intake air heating or blending with lightly boiling components. All of these incur expenses for additional component and processes. One of the cold start procedures presented in this paper enables the cold start of pure methanol down to –20 °C, without the necessity for additional engine components. For this the serial hybrid propulsion system is used. The electric machine was used to motor the ICE at high engine speeds and strongly throttled with minimal fuel mass, to allow for fuel evaporation in the intake and heating during the compression stroke. A 3D-CFD simulation was setup the explore the procedure. The new procedure is compared to a conventional process with air and fuel heating.