Travail de fin d'études: "Literature review of biomethane production, with a preliminary life-cycle assessment and techno-economic analysis of an innovative biomethane production process (European Union - HYFUELUP Project)"

Abstract

The transition to sustainable biomethane production is gaining momentum as a viable alternative for decarbonizing the transportation industry in particular long-distance road-freight and maritime transportation. The European Union HYFUELUP project aims to demonstrate an innovative pathway for biomethane production via the integration of sorption-enhanced gasification (SEG), fluidized bed methanation and electrolysis. The National Laboratory of Energy and Geology (LNEG) in Portugal, where this thesis was completed, is responsible for the life-cycle assessment (LCA) and techno-economic analysis (TEA) of the HYFUELUP project. This thesis aims to provide a comprehensive review of biomethane production and gasification technologies, emphasizing the need to shift from the conventional anaerobic digestion process to gasification. Moreover, to support this analysis, existing LCA and TEA data using similar technologies were reviewed aiming to provide a basis for comparison and guide data collection for the HYFUELUP project. The use of biomethane as a sustainable energy alternative can enhance energy security, significantly reduce emissions in the transport sector and reduce dependence on external providers. Gasification technologies such as SEG and methanation holds great potential for future biomethane production however substantial support from governments and companies will be needed for scaling up these processes and making them economically feasible.

Three studies from the literature were chosen for TEA analysis and three studies for LCA analysis. The TEA data examined in this thesis revealed various factors influencing capital and operating costs where study A – which closely resembled the HYFUELUP project – showed the highest overall costs. Electrolysis was identified as a major cost driver, and the overall costs were expected to increase with larger functional units. The LCA data was converted via normalization factors to allow for a more accurate comparison between studies, where study A had the higher global warming potential possibly due to the fact that the system boundaries were larger than the other studies investigated. Experimental data in the literature is still lacking, where further research is needed for a more comprehensive analysis of TEA and LCA of this integrated biomethane production process. A preliminary life cycle inventory and techno-economic cost estimation are also presented based on the existing literature. By considering the findings from this thesis, and the ongoing work of the HYFUELUP project, it is evident that biomethane has potential for decarbonizing the transport sector and emissions reduction. Future efforts should focus on the need for implementing regulations and policies to drive the widespread adoption of biomethane technologies.