The Pipeline Technology Community has long been evaluating the blend of hydrogen into the gas distribution grid, as a means of reducing the carbon footprint of this existing energy infrastructure. Ideally, hydrogen would be produced by using renewable energy, delivering net carbon footprint reduction; alternatively, any other low-carbon hydrogen production route would apply.

The Baker Hughes and Snam Companies have already partnered in 2020 to verify the blending on a real production gas turbine, in internal test in Firenze (Italy). In November 2022, the same Companies have taken the same collaboration one step further, by verifying the blend operability at a real and operational pipeline compressor station. The selected station was Istrana (Italy), where two (2) PGT25 DLE in operation since 1997 and two (2) NovaLT^TM 12 new units just installed. Gas Turbines H₂ readiness of technologies developed in XX e XXI centuries were compared.

Thanks to a dedicated blending skid, the turbines were verified in their operability with variable mixtures in the range 0-10%vol of hydrogen, including transients in various operating modes, with particular focus on emissions compliance and efficiency. With respect to the benchmark emissions with natural gas only, H₂ blends up to 10%vol provided areas of additional stability (reduced combustion pressure pulsations) and very limited NO_x increase, without changing mapping parameters. The additional stability, as well as the CO reduction, showed opportunities to further optimize NO_x when allowing the change of mapping parameters. As a result of 10% H2 blending, CO2 footprint reduces by approximately 4%. This may look a small gain at station-scale but would be a significant improvement at European Union scale.