Techno-economic feasibility and CO 2 emission analysis of a novel biogas to blue gold multi-generation process: a simulation of cryogenic processes for efficient CO 2 management and energy production

This work presents an eco-friendly novel biomass-based integrated energy system that combines cryogenic separation of biomass with gas turbines, steam Rankine, absorption chillers, and water electrolyser units. The main contribution of the system is the utilisation of nitrogen-based cryogenic cycles, which guarantees improved thermal and power integration by allowing for simultaneous production of high-purity biomethane and liquid CO2 from biomass. This study utilises a thorough 4E evaluation that includes thermodynamic, environmental, and exergo-economic analyses. Based on the results, the cryogenic process successfully recovers 99.61% of the biomethane, which leads to strong resource utilisation with an energy efficiency of 59.59% and an exergy efficiency of 29.16%. Moreover, the proposed process exhibits both economic viability and efficient emission management by achieving a low footprint of 0.1669 kg/kWh and a specific product cost of $39.81/GJ, due to its high biomethane recovery and efficient liquid CO2 capture.