Project E2Fuels: new publication on combustion behavior of natural gas-hydrogen-mixtures

TUM.PtX News |

Hydrogen from water electrolysis can be stored within the natural gas grid and provide a large energy storage capacity. Due to the specific combustion properties of hydrogen, however, engines and CHP fueled with natural gas are subject to investigations on the effects of hydrogen addition on their operating behavior.

At the Chair of Sustainable Mobile Drivetrains, a single-cylinder research-engine with a displacement of 4.8 liters and optical access to the combustion chamber was developed for the thermodynamic and optical investigation of natural gas combustion. The engine is equipped with an in-house developed endoscope with fisheye-characteristics, which consists of 9 lens elements in 7 groups and offers a 180° field of view. The complete combustion chamber becomes visible without the high constructive effort of conventional transparent engines with glass-piston [doi].

In first experiments, the engine was fired with natural gas and mixtures of natural gas with up to 40 vol% hydrogen. Gas blends with up to 10 vol% hydrogen did not affect combustion behavior significantly, so that storage of moderate amounts of hydrogen in the gas grid is unlikely to cause issues with existing systems. Higher hydrogen content, however, may lead to increased formation of nitrogen oxides, so that engine calibration has to be adapted [doi].