Non-road sectors, such as agriculture and construction machinery, require high energy densities and flexibility in use, which is why diesel engines are mainly used. The use of climate-neutral fuels, produced from renewable energies, such as Oxymethylene Ether (OME) as a diesel substitute, can significantly reduce CO${}_2$ and pollutant emissions in these sectors. In addition to CO${}_2$ neutrality, OME also offers improved combustion characteristics compared to diesel fuel, eliminating the soot–NO${}_{\mathrm{x}}$ trade-off and thus enabling new opportunities in engine design and calibration. In this paper, the combustion of pure OME on a close-to-production, single-cylinder non-road diesel engine with a pump–line–nozzle injection system is analyzed. A variation of the center of combustion at constant power output was performed for diesel and OME at different operating points. Two injectors were investigated with OME. A study on ignition delay and a detailed thermodynamic analysis was carried out. In addition, the exhaust emissions CO, NO${}_{\mathrm{x}}$, $VOC$, as well as particulate-matter, -number and -size distributions were measured. With OME, a significantly shorter ignition delay as well as a shortened combustion duration could be observed, despite a longer injection duration. In addition, the maximum injection pressure increases. $VOC$ and CO emissions are reduced. Particulate matter was reduced by more than 99% and particle number (>10 nm) was reduced by multiple orders of magnitude. The median of the particle size distribution shifts from 60 to 85 nm (diesel) into a diameter range of sub 23 nm (OME). A significant reduction of NO${}_{\mathrm{x}}$ emissions with OME enables new degrees of freedom in engine calibration and an efficiency advantage without hardware adaption.

The atmospheric pressure plasma jet (APPJ) is a popular type of cold atmospheric plasma (CAP). APPJs based on a pulsed atmospheric arc (PAA) are widely spread in industrial processing. A plasma jet of this type, PlasmaBrush PB3 (PB3), is a subject of diverse research activities. The characteristic feature of PB3 is the generation of a low-current (300 mA), high-voltage (1500 V) pulsed (54 kHz) atmospheric arc. A gas flow vortex is used to stabilize the arc and to sustain the circular motion of the cathodic arc foot. During long periods of operation, nozzles acting as arc discharge cathodes erode. Part of the eroded material is emitted as nanoparticles (NPs). These NPs are not wanted in many processing applications. Knowledge of the number, type, and size distribution of emitted NPs is essential to minimize their emissions. In this study, NPs in the size range of 6 to 220 nm, emitted from four different nozzles operated with PB3, are investigated. The differences between the nozzles are in the eroded surface material (copper, tungsten, and nickel), the diameter of the nozzle orifice, the length of the discharge channel, and the position of the cathodic arc foot. Significant differences in the particle size distribution (PSD) and particle mass distribution (PMD) of emitted NPs are observed depending on the type and condition of the nozzle and their operating time. Monomodal and bimodal PMD models are used to approximate emissions from the nozzles with tungsten and copper cores, respectively. The skew-normal distribution function is deemed suitable. The results of this study can be used to control NP emissions, both to avoid them and to utilize them intentionally.