(526c) Hydrogen Enriched Syngas through Calcium Looping Gasification of Biomass

This study investigates the potential use of eggshell as a CO₂ sorbent in the calcium looping gasification of biomass to enhance carbon negativity and hydrogen enrichment. Calcination reaction was studied in a quartz wool matrix reactor and a thermogravimetric analyser coupled with a Fourier transform infrared spectroscopy. The resulting sorbent was characterised with an inductively coupled plasma optical emission spectroscope (ICP-OES), scanning electron microscope (SEM), nitrogen sorption analyser and colourimeter. Results showed that increasing the calcination temperature enhances the decomposition and improves the calcium content in the sorbent. Also, the specific surface area of the sorbent was improved by the calcination process, enhancing its reactivity. As compared to nitrogen, calcination in a CO₂ environment is not effective due to an increase in the CO₂ partial pressure. Results also showed that samples with low particle size displayed higher carbonation conversion. Increasing the carbonation temperature to an extent enhances the carbonation conversion. The carbonation conversion by the sorbent in multiple calcination-carbonation cycles was also studied. Initial CO₂ uptake by the sorbent was highly encouraging. A conversion of 76.41% was realized after the first cycle, but due to sintering and attrition, the conversion reduced with increasing cycle. The sorbent exhibited a low conversion of 18% after the seventh cycle, which corresponds to a decay extent of 76.65%.