Biogenous ethers: production and operation in a diesel engine

Abstract

Fuels from lignocellulosic biomass have the potential to contribute to sustainable future mobility targets by reducing the fossil CO 2 emissions of the transport sector. Of special interest for the diesel engine are oxygenated fuels, since they can help to solve traditional conflicts of objectives like the soot-NOx trade-off or the efficiency-NOx compromise. Dibutyl ether (DBE) and oxymethylene ethers (OME) are among the most promising fuel candidates. The suitability of these compounds for diesel engines is investigated in this study. The fuels are injected in pure form as well as a diesel-biofuel blend with 20% volumetric biogenic share. During the course of these investigations special attention is given to soot and particle emissions, and also to measured engine efficiency. The combustion tests are combined with an analysis of suitable production paths of the evaluated bio-ethers as second generation biofuels. Production simulation shows high greenhouse gas savings potential, but also high investment costs.

Future Fuels—Analyses of the Future Prospects of Renewable Synthetic Fuels

“…The authors also emphasized that NO x emissions are mostly dominated by the exhaust gas recirculation (EGR) rate, while fuel properties become more relevant at low EGR rates. Nevertheless, several studies showed higher raw NO x emissions from DMM-/OME n -diesel blend combustion regardless of the level of the blending rate [52,53,56]. The reasons for this are the longer phases of higher temperatures and locally increased λ values with OME n combustion, higher flame temperatures, and the lower LHV of OME n (blends), leading to a higher oxygen concentration in the exhaust gas compared to diesel fuel.…”

“…Several studies showed significant soot and therefore PM emission reduction for small DMM/OMEn blending rates at low load points. However, when loads are increased, PM reductions decrease or become zero [56,57]. Furthermore, Oxygenated fuels reveal a high particulate emission reduction potential through the oxygen content in the fuel molecular structure.…”

“…The baseline of the PM emission reduction relating to DMM/OME n is also their high oxygen content and further, the lack of C-C compounds, which increases the soot oxidation rate [52,53]. Similarly to butanol, these fuels show an increase of PM/PN reduction with increasing blending rates, but as a difference, they yield the highest emission reductions as neat fuels (see [56,57,62]). There are, however, some exceptions that need to be mentioned.…”

“…Several studies showed significant soot and therefore PM emission reduction for small DMM/OME n blending rates at low load points. However, when loads are increased, PM reductions decrease or become zero [56,57]. Furthermore, studies showing PM reductions for smaller OME n blending rates stated that PN emissions can still rise above diesel fuel levels, assuming that fine particles which originate from diesel fuel are responsible for this.…”

Recent Progress in the Production, Application and Evaluation of Oxymethylene Ethers

“…Production of hydrogen by water electrolysis employing electricity from wind power is a key step of this procedure. In a very recent study, production of different oxygenate fuels (fatty acid methyl ester, dibutyl ether and OMEs) has been evaluated and the advantages of OMEs have been outlined .…”