Biogenic waste thermochemical valorization: Integration of experimental results and process modelling within the GICO project

This study investigates the GICO (Gasification Integrated with CO₂ Capture and Conversion) concept, an innovative biogenic waste treatment scheme combining hydrothermal carbonization (HTC), sorption-enhanced gasification (SEG), hot gas cleaning (HGC), plasma-assisted CO₂ conversion, methanol synthesis, and solid oxide fuel cell (SOFC). Experimental campaigns were carried out on winery residues as representative wet biomass. HTC produced hydrochar with improved fuel properties (C/O ratio increased to 61 %) that was then processed in SEG tests, yielding hydrogen-rich syngas (75.8 vol%) with a cold gas efficiency (CGE) of 75.5 %. These data were used to calibrate an Aspen Plus model of a pilot-scale plant treating 550 kg/h of wet biomass. The model successfully reproduced experimental results enabling a methanol synthesis of 66 kg/h (CGE 42.4 %). The SOFC subsystem generated 259 kWh of electricity and 215 kWh of recoverable heat, expanding the product distribution. Overall, the process efficiency reached 32.4 % limited by the process energy demand, mainly due to the plasma reactor, highlighting the potential of a reduced-plasma-feed configuration achieving 39.7 % efficiency. Preliminary heat recovery strategies reduced external requirements by 88.5 % and increased the overall efficiency to 38.9 %, and the carbon utilization at 84.5 % highlighting the crucial role of thermal integration in optimizing the GICO process. • A model of advanced and flexible process for bio-waste exploitation is developed. • The model integrates HTC, SEG, Plasma, Methanol synthesis, and SOFC. • Experimental results are used to validate HTC and SEG subprocesses. • Methanol, electricity, and an high purity CO 2 stream are produced. • Heat integration analysis enables heat requirements reduction of nearly 88 %.