The CO2 adsorptive and regenerative behaviors of Rhizopus oligosporus and carbonaceous Hibiscus cannabinus exposed to thermal swings

Rhizopus oligosporus and carbonaceous Hibiscus cannabinus L. were artificially converted into active bio-sorbents to study their CO2 adsorptive and regenerative capacities under thermal fluctuations. A naturally dried Tempe (soybean slab) demonstrated CO2 adsorption of 0.10 mol/g in the first cycle, while, carbonaceous Tempe comprising 54.69% of carbon content demonstrated CO2 adsorption of 0.06 mol/g. The relatively higher adsorption by the dried Tempe was attributed to the presence of active R. oligosporus micro-sites. Despite lower affinity, carbonaceous Tempe was superior in term of its thermal durability and adsorption consistency. Carbonaceous Kenaf (H. cannabinus L.) with ZnCl2 promoter at a ratio of 3:5, comprising 63.29% of active carbon content, demonstrated the highest CO2 adsorption of 17.39 mol/g in the 56 min run, hundreds folds higher than that demonstrated by the dried Tempe. The carbonaceous Kenaf, also found to be highly resilient against repeated heating, however, exhibited rather meager regenerative capability compared to the sample containing smaller amount of zinc chlorides.