Potential Analysis of a DMC/MeFo Mixture in a DISI Single and Multi-Cylinder Light Vehicle Gasoline Engine

Abstract

<div class="section abstract"><div class="htmlview paragraph">In this study a mixture of dimethyl carbonate (DMC) and methyl formate (MeFo) was used as a synthetic gasoline replacement. These synthetic fuels offer CO<sub>2</sub>-neutral mobility if the fuels are produced in a closed CO<sub>2</sub>-cycle and they reduce harmful emissions like particulates and NO<sub>X</sub>. For base potential investigations, a single-cylinder research engine (SCE) was used. An in-depth analysis of real driving cycles in a series 4-cylinder engine (4CE) confirmed the high potential for emission reduction as well as efficiency benefits.</div><div class="htmlview paragraph">Beside the benefit of lower exhaust emissions, especially NO<sub>X</sub> and particle number (PN) emissions, some additional potential was observed in the SCE. During a start of injection (SOI) variation it could be detected that a late SOI of DMC/MeFo has less influence on combustion stability and ignitability. With this widened range for the SOI the engine application can be improved for example by catalyst heating or stratified mode. Furthermore, until λ = 0.8 no significant PN increase was noted in contrast to gasoline. This is also a positive capability for combustion modes with local rich areas in the mixture. From the experience of previous investigations, the synthetic fuels’ high knock-resistance potential enabled an increase in the compression ratio (CR) from epsilon ~ 11 to ~ 15 to enhance the indicated efficiency.</div><div class="htmlview paragraph">In general, in the 4CE the positive effects of DMC/MeFo on harmful emissions were confirmed. Even in the series configuration, the brake efficiency increased by 16 % at maximum low-end torque compared to gasoline. The increased in-cylinder cooling and the lower laminar flame temperature by the DMC/MeFo implies lower maximum exhaust temperatures. Therefore, a stoichiometric mixture could be used over the whole engine map. During the legislative driving cycles, for example WLTC, the PN, NO<sub>X</sub>, CO and CH<sub>4</sub> emissions decreased by 50 % or more.</div><div class="htmlview paragraph">In summary, oxygenated fuel opens great opportunities for replacing fossil fuel in gasoline engine applications.</div></div>

Synthesis of Methylal and Poly(oxymethylene) Dimethyl Ethers from Dimethyl Ether and Trioxane

“…Furthermore, a strategy for using the MeFo would be needed. MeFo is used on a large scale, e.g., for the production of formic acid, but it has recently also been discussed as synthetic fuel. , …”

“…MeFo is used on a large scale, e.g., for the production of formic acid, but it has recently also been discussed as synthetic fuel. 69,70 The present work provides the basis for a more realistic assessment of the route leading from formaldehyde and DME to OME.…”

Continuous Synthesis of Oxymethylene Ether Fuels from Dimethyl Ether in a Heterogeneously Catalyzed Liquid Phase Process

“…The main byproduct methyl formate (MeFo), which is currently investigated as a substitute for fossil gasoline [33,34], is formed from two molecules of FA in a Tishchenko reaction according to Eq. ( 6) [35].…”

Modeling the Effects of the Ignition System on the CCV of Ultra-Lean SI Engines using a CFD RANS Approach

“…he Spark-Ignition (SI) engine technology is currently under continuous improvement, in order to achieve, simultaneously, the maximum thermal efficiency as well as near-zero pollutant and green-house gases emissions [1,2,3,4,5,6]. This high industrial and academical interest is justified by several aspects, such as the low cost, the high power-to-weight ratio and the fuel flexibility, which make SI engines as one of the most interesting and feasible solutions towards a complete decarbonization of vehicles powertrain technology [7,8,9]. In this framework, combustion efficiency and control become fundamental at all conditions covered by the engine map [10,11].…”