Storage of carbon dioxide captured in a pilot-scale biogas upgrading plant by accelerated carbonation of industrial residues

This work reports the preliminary evaluations obtained within the UPGAS-LOW CO2 project (LIFE08 ENV/IT/000429) concerning innovative methods for biogas upgrading through CO2 capture and storage. One of the methods studied in this project is chemical absorption of the CO2 contained in landfill gas with a KOH solution followed by carbonation of the spent solution with selected industrial residues to regenerate the alkaline solution and store CO2 in a solid phase (calcite). This paper presents the main results of the lab scale experiments carried out to evaluate the effects o f the main operating parameters on the carbonation reaction so to identify the conditions that allow to maximize the CO2 uptake of the solid residues and the percentage of KOH that can be regenerated for the absorption process. These results provide the dataset for the design of a pilot plant unit to be built and operated in the follow-up of the project.