Hydrogen

Hydrogen (H2) is essential in the energy transition toward attaining a carbon-neutral world. H2 has been used for decades in traditional sectors such as refineries (for hydrotreatment), petrochemicals, and fertilizers (ammonia). H2 generation is typically done through steam methane reforming (SMR) from natural gas (=grey H2), where large volumes of CO2 are vented. Regulations get stricter to capture the CO2 emissions with CCS technologies (=blue H2). And new technologies, based on a water electrolysis process driven by renewable electricity, are emerging fast. This way, H2 is generated with zero CO2 emissions (= green H2) and can be used as a clean energy carrier or as building block for clean transport fuels.

• Green H2 generation: various electrolysis technologies exist, based on liquid alkaline (AEL), proton exchange membranes (PEM) or solid oxide (SOE). Each technology has its challenges and benefits.
• Green H2 transport & storage: various transport options are in use and in different phase of maturity: Liquid H2 at -253°C, Compressed gaseous H2 (pipelines, ~80bar), converted to ammonia (NH3) for easier handling (at 20 bar, or at -33°C), converted into a liquid organic hydrogen carrier (mainly oil derivates, such as toluene or methanol / liquid at 1bar).
• Green H2 conversion: typical processes include Haber-Bosch process to convert H2 with nitrogen into green Ammonia, and Fischer-Tropsch process to convert H2 with CO into liquid e-fuels. Both processes are complex and require temperature maintenance applications.