Abstract
This PhD thesis investigates whether green hydrogen and CO2 reuse technologies are in line with the Paris Agreement goals of halving global CO2 emissions by 2030 and reducing them to net zero by 2050. Expectations for these technologies, also known as ‘net-zero’ technologies, are high: green hydrogen is hailed as the ‘gas of the future’ and CO2 reuse as a ‘sustainable form of waste treatment’. To be effective, these technologies must be available on time and reduce emissions along the entire chain, including those from plant construction materials and energy use.
Some CO2 reuse options show potential for 2030, for example in construction materials and greenhouses, but strict conditions are needed to meet the 2050 goals, such as emission-free production processes, CO2 reuse from biomass or air, and permanent CO2 storage. Green hydrogen performance varies widely based on electricity sources and integration into the energy system, with more efforts needed to reduce emissions, especially in transport. Although green hydrogen and CO2 reuse technologies play a role in energy and industrial transitions, they are rarely completely emission-free. It is therefore important not to label them as ‘net-zero’ technologies, but to recognise their contribution to residual emissions, and consider whether the context in which they are implemented actually leads to the intended results, now or in the future.
