Green Methanol – A CO2 Neutral Energy Carrier Enabling 50+% Engine Efficiency with Ultra-Low Pollutant Emissions

Authors

A. Güdden MSc, Prof. S. Pischinger, RWTH Aachen University; Dr.-Ing. J. Geiger, Dipl.-Wirt.-Ing. B. Heuser, Dr.-Ing. M. Müther, FEV Europe GmbH, Aachen:

Year

2021

Print Info

Production/Publication ÖVK

Summary

The decarbonization of aviation, shipping and long-distance haulage of goods represents significant challenges. In this context, the application of synthetic fuels is a timely feasible alternative for the mentioned sectors and their specific requirements. Starting from renewable electric energy, methanol is the simplest liquid synthetic fuel and one of the most promising alternative fuels for shipping. Methanol is suitable for both compression- and positive ignition combustion. Hence, this publication addresses the possible combustion systems and identifies the most promising alternatives. On the one hand, methanol can be burned diffusively with pilot fuel assist. This concept offers efficiencies above conventional diesel engines (>50% indicated efficiency, same load range). At the same time, the soot-NO_X-trade-off improves very significantly depending on the diesel fuel share. On the other hand, combustion of premixed methanol/air charges with positive ignition promises high efficiencies due to methanol’s cold yet fast combustion. For large bore engine applications in the marine sector, premixed lean burn combustion enables IMO Tier III NO_X compliance (<2 g/kWh) without exhaust gas after treatment. For commercial vehicle applications on the other hand, a stoichiometric spark ignition engine with EGR and a three-way catalyst offers high efficiencies and a relatively simple after treatment system. While the diffusive concept offers superior efficiency and load response, the premixed combustion concepts also allow very low emission limits to be reliably met.

Number of pages

16 Order