Seasonal energy and environmental characterization of a micro gas turbine fueled with H2NG blends

This paper deals with the seasonal energy and environmental characterization of a commercial micro gas turbine fueled with hydrogen enriched natural gas blends, to implement a Power-to-Gas option. When the renewable electricity excess occurs in a hybrid system, that energy can be converted into hydrogen to increase micro-turbine environmental performance. The experimental approach consists of testing on field that device at rated and partial load over the hot and cold seasons. The energy and environmental performance, along with the method to properly allocate the pollutants emissions for such applications, have been presented when the hydrogen fraction ranges in 0% vol. - 10% vol, by means of a 2% vol. step. From the main findings it emerges that both heat recovery and electrical efficiency undergo a slight increase even if the machine is strongly affected by the environmental derating. However, the larger beneficial effects occurred over the summertime, since the hydrogen mixtures can partially offset the outdoor environmental conditions change. Indeed, beyond the hydrogen fraction of 6% vol. and beyond 15 kW of electric output, the enrichment increases the rotational speed providing a leaner combustion. In so doing, the CO emissions are equal to zero, while the NOx are almost constant.