TY - GEN A1 - Ruffert, Christine A1 - Monsalve Guaracao, Jorge Mario A1 - Völz, Uwe A1 - Jongmanns, Marcel A1 - Betz, Björn A1 - Langa, Sergiu A1 - Amelung, Jörg A1 - Wiersig, Marcus T1 - Rapid characterisation of mixtures of hydrogen and natural gas by means of ultrasonic time-delay estimation T2 - Journal of Sensors and Sensor Systems N2 - The implementation of the “power-to-gas” concept, where hydrogen and natural gas are blended and transported in the existing network, requires a quick, on-site method to monitor the content of hydrogen in the mixture. We evaluate a rapid characterisation of this mixture based on the measurement of the speed of sound, using micromachined ultrasonic transducers (MUTs). Two MUT-based prototypes were implemented to analyse a mixture of natural gas and hydrogen under controlled conditions. Changes in the hydrogen content below 2 mol % (in a mixture that was adjusted between 6 mol % and 16 mol %) were discriminated by both devices, including the uncertainty due to the temperature compensation and the time-delay estimation. The obtained values of the speed of sound were consistent with those calculated from independent, non-acoustic measurements performed with a gas chromatograph and a density sensor. An MUT-based flow meter is thus capable of reporting both gas intake and the molar fraction of hydrogen, provided that the source of natural gas is kept constant. Y1 - 2024 U6 - https://doi.org/10.5194/jsss-13-179-2024 SN - 2194-878X VL - 13 IS - 2 SP - 185 ER -