Environmental assessment of an integrated hydrothermal carbonisation-aqueous phase reforming-gasification plant using biogenic feedstock

Proceedings of the oral presentation made at EUBCE 2025, Valencia, Spain. To maximize the valorisation of biogenic waste streams, the EU-funded NIAGARA project proposes a new integrated biorefinery design. This new biorefinery design targets to maximise valorisation and circularity of carbon and energy contained in different biogenic feedstocks. The novelty of NIAGARA design is to combine hydrothermal carbonisation (HTC), aqueous phase reforming (APR), and gasification in a single integrated refinery to produce a gaseous biofuel from various [liquid] feedstocks. This is a pioneer work integrating these technologies and optimizing feedstocks from real-world waste streams combined with microalgae grown with recycled carbon. This paper focuses on the environmental evaluation of the NIAGARA biorefinery integrating the technologies through a life cycle assessment (LCA). The NIAGARA’s project goal is to achieve 30% reduced impacts (e.g., greenhouse gas equivalent emissions) compared to conventional (bio)fuels. To assess the novel NIAGARA plant, several concepts from LCA literature will be combined. Specifically, the LCA inventories will be parametrised to reflect appropriately the impacts from different feedstock compositions and varying process conditions. Further, the study will build on energy-optimized scenarios considering the benefits of heat integration. In the use stage, different market applications, such as solid oxide fuel cells and the production of a liquid biofuel will be compared. This contribution describes in detail the methodology used to perform the environmental assessment including the LCA’s goal and scope definition, system boundaries, a description of the relevant flows in the system, and an indication of how parameters are treated in the assessment. Additionally, any preliminary results from the project’s assessment are compared to NIAGARA´s target and to literature results on alternative pathways (including anaerobic digestion). This paper informs about the pioneering EU NIAGARA project and its technology, which can further help researchers to design adequate assessment strategies for similar technologies. In the wider context, this research contributes to environmental sustainability and climate change mitigation.