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Gaseous methane fuel for internal combustion engines have proved to be a competitive source of propulsion energy for heavy duty truck engines. Using biogas can even reduce the carbon footprint of the truck to near-zero levels, creating fully environmentally friendly transport. Gas engines have already been on the market and proved to be a popular alternative for buses and waste transport. However, for long haulage these gas engines have not been on par with the equivalent diesel engines. To improve the power and efficiency of EURO VI gas engines running stoichiometrically, a direct way forward is adding more boost pressure and spark advance in combination with more EGR to mitigate knock. Using in-cylinder turbulence to achieve higher mixing rate, the fuel can still be combusted efficiently despite the increased fraction of inert gases.

Clean combustion is one of the inherent benefits of using a high methane content fuel, natural gas or biogas. A single carbon atom in the fuel molecule results, to a large extent, in particle-free combustion. This is due to the high energy required for binding multiple carbon atoms together during the combustion process, required to form soot particles. When scaling up this process and applying it in the internal combustion engine, the resulting emissions from the engine have not been observed to be as particle free as the theory on methane combustion indicates. These particles stem from the combustion of engine oil and its ash content. One common practice has been to lower the ash content to regulate the particulate emissions, as was done for diesel engines. For a gas engine, this approach has been difficult to apply, as the piston and valvetrain lubrication becomes insufficient.