Continental has successfully conducted tests on the synthetic diesel fuel oxymethylene ether (OME) in test vehicles, including its Super Clean Electrified Diesel vehicle presented this year. Overall, the Continental tests confirmed that diesel fuel containing 15% OME blend for current diesel engines is a technically safe and viable possibility for reducing greenhouse gas emissions. A 15% OME blend reduces CO2 emissions by approximately 8g/km.
Oxymethylene ethers are synthetic compounds of carbon, oxygen, and hydrogen (CH3O(CH2O)nCH3). Due to their high oxygen concentration, they suppress pollutant formation in combustion. As diesel fuels, they reduce the emission of carbon black and NOx. Germany launched a 3-year study of oxymethylene ethers (OME) as clean diesel fuels in 2016 (earlier post) and Ford is leading a €3.5-million (US$3.9-million) research project, co-funded with the German government, to test cars running on monooxymethylene ether (OME1) and DME. (Earlier post.)
Synthetic fuels do not only contribute to CO2-neutral mobility. For instance, OME produces almost no soot when burned. Continental is therefore actively promoting vehicle technology for the use of synthetic fuels. Our objective is to create a transition phase in which normal driving does not contribute to climate change. We have made most progress with OME for diesel applications.—Dr. Oliver Maiwald, head of Technology & Innovation at Continental’s Powertrain division
With the soot-free oxidation of OME allows higher EGR rates without any contamination of the EGR coolers; the well-known NOx/particle trade-off is avoided (Münz et al.). This opens the door for alternative strategies for the engine operation, including new engine concepts and exhaust gas aftertreatment systems.
The economical production of synthetic fuels is one of the central challenges; process technology for manufacturing OME on an industrial scale is still in development.
It is therefore pragmatic to assume a gradual introduction of OME. With this in mind, we have now carried out an initial test of diesel containing OME. Our vehicle tests have shown that a 15 percent OME admixture in diesel fuel—in addition to the current 7% of biofuel—is already usable in engines today.—Dr. Gerd Rösel, head of Advanced Engineering at Engine Systems business unit, Powertrain division
Every fuel has specific characteristics, according to which an engine and all of its components must be designed. This means that the use of OME in engines has an effect on the entire process chain from the injection system and combustion through to the composition of raw emissions, exhaust-gas aftertreatment, sensor technology and diagnostics.
For this reason, Continental said, it is necessary to prepare basic research into the corresponding technologies for gradually increasing the percentage of OME.
In order to use higher concentrations of OME in diesel, we need to consider the entire reaction pathway. With its end-to-end expertise from injection molding to exhaust-gas aftertreatment including SCR, Continental is optimally positioned for this.—Rolf Brück, head of the Catalytic Converters product line in the Fuel & Exhaust Management business unit of the Powertrain division
Münz M., Feiling A., Beidl C., Härtl M., Pélerin D., Wachtmeister G. (2016) “Oxymethylene ether (OME1) as a synthetic low-emission fuel for DI diesel engines.” In: Liebl J., Beidl C. (eds) Internationaler Motorenkongress 2016. Proceedings. Springer Vieweg, Wiesbaden doi: 10.1007/978-3-658-12918-7_41