Project: MUT4H2 - Characterization of the hydrogen content in natural gas systems

The use of hydrogen as an energy carrier is an essential building block for the energy transition. In addition to production, transport and distribution are important aspects for green hydrogen. Among other things, existing natural gas pipelines are to be used for this purpose. However, in order for end users on site to be able to use the gas mixtures safely and effectively, precise knowledge of the gas mixture is essential. Therefore, the MUT4H2 project is the first to develop a new technology for measuring gas mixtures based on micromechanical ultrasonic elements (MUT), which enable compact and inexpensive analysis as well as decentralized monitoring and control of local systems.

Today, the characterization of gaseous systems, such as hydrogen in the natural gas system, is mainly realized by means of gas chromatographs. However, this method is too expensive, especially for smaller gas systems at the end user (home and industry). In these applications, diaphragm gas meters, rotary piston meters or turbine meters are still used. However, if hydrogen-natural gas mixtures are to be used in the future, an accurate measurement method is needed to ensure the suitability of existing heating systems at the end users. Existing systems are suitable up to an H2 admixture of 10% by volume; above this, the systems must be adapted. The novel measurement system being developed in the MUT4H2 project is based on ultrasonic measurements by means of micromechanical ultrasonic elements (MUT), which enable inexpensive and uncomplicated measurement of gas proportions and flow velocity, e.g. of the hydrogen content in natural gases at the consumer. The Fraunhofer IPMS is developing a multi-sensor system consisting of a flow sensor, a hydrogen sensor, a pressure sensor and a temperature sensor. The flow sensor is being developed based on the technology for capacitive micromechanical ultrasonic sensors (CMUT) for non-corrosive gases. For the hydrogen sensor, the institute relies on a NEDMUT-based sensor for non-corroding binary gases based on sound velocity measurement. The integration of all individual sensors into a compact measurement system places high demands on the stability of the platform. The project aims to develop a compact and cost-effective integration technology (< 50 cm³) that includes a pre-processed digital interface for direct connection to a control unit. The demonstrator developed is thus intended to form the basis of a multi-sensor system for the compact and cost-effective characterization of gas mixtures in the field of industry and mobility.