Oxymethylene Ether Combustion and Synthesis in Diesel Engines

Oxymethylene ethers (OMEs) are a family of synthetic oxygenated compounds under investigation as alternatives or additives to conventional diesel in compression ignition engines. Their high oxygen content, absence of carbon–carbon bonds and tunable molecular weight confer low sooting tendency, reduced particulate emissions and potential for substantial net carbon savings when produced from renewable feedstocks. Synthesis routes typically involve catalytic conversion of methanol and formaldehyde, with emerging gas-phase and liquid-phase processes promising higher selectivity and intensified production. Detailed chemical-kinetic models have been developed to capture the low-temperature decomposition pathways and radical chemistry of OMEs, informing engine-level simulations and combustion strategies. In practical engine trials, blends of OMEs with diesel have demonstrated shorter combustion duration, modest gains in thermal efficiency and significant reductions in soot and nitrogen oxide emissions, although lower energy density and fuel-system compatibility remain challenges. Techno-economic and life-cycle assessments underline the global significance of OMEs in decarbonisation efforts, highlighting the balance between hydrogen and carbon dioxide supply, catalyst development and infrastructure adaptation required for large-scale deployment.

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Oxymethylene Ether Combustion and Synthesis in Diesel Engines publication trend

The graph below shows the total number of articles in oxymethylene ether combustion and synthesis in diesel engines across all publications each year (not limited to Nature Index journals).

Technical terms

Oxymethylene ethers (OMEs): A class of polyoxymethylene dimethyl ethers (CH₃O(CH₂O)ₙCH₃), used as oxygenated synthetic fuels for compression ignition engines due to their high oxygen content and clean-burning properties.

Compression ignition engine: An internal combustion engine in which fuel is injected into highly compressed hot air, causing auto-ignition without a spark plug.

Life cycle assessment (LCA): A methodology for quantifying the environmental impacts associated with all stages of a product’s life, from raw material extraction through production, use and disposal.

Chemical kinetics: The study of reaction rates and mechanisms in combustion, essential for developing accurate ignition and emission predictions.

Flame lift-off length: The axial distance between the fuel injector and the region where a stabilised flame first appears in a compression ignition engine.

References

1. Potential of oxymethylene ethers as renewable diesel substitute. Progress in Energy and Combustion Science (2024).
2. Performance and emissions of renewable blends with OME3-5 and HVO in heavy duty and light duty compression ignition engines. Fuel (2021).
3. Techno-economic assessment and carbon footprint of processes for the large-scale production of oxymethylene dimethyl ethers from carbon dioxide and hydrogen. Sustainable Energy & Fuels (2022).
4. Simultaneous high-speed spectroscopy and 2-color pyrometry analysis in an optical compression ignition engine fueled with OMEX-diesel blends. Combustion and Flame (2021).
5. Gas-phase synthesis of oxymethylene ethers over Si-rich zeolites. Green Chemistry (2018).
6. Continuous Synthesis of Oxymethylene Ether Fuels from Dimethyl Ether in a Heterogeneously Catalyzed Liquid Phase Process. Chemie Ingenieur Technik (2022).
7. Renewable OME from biomass and electricity—Evaluating carbon footprint and energy performance. Energy Science & Engineering (2020).
8. Numerical and Experimental Investigations on the Ignition Behavior of OME. Energies (2022).