摘要
Carbon dioxide(CO_(2))is the main contributor to greenhouse gases that affect global warming.The industrial sector is the third largest producer of CO_(2) and the cement industry is one of the industries that consistently produces the most significant CO_(2) emissions.The cement industry produces 5-8% of global CO_(2) emissions.Several methods for reducing specific CO_(2) emissions have been reported in the cement industry,including calcium looping,which uses the reversible reaction between calcination[calcium carbonate(CaCO_(3))decomposition]and carbonation[CO_(2) capture by calcium oxide(CaO)].This work investigates calcium looping employing limestone obtained directly from several cement factories in Indonesia to observe the carbon-absorption characteristics of limestone from different mining locations.The experiment was carried out using a tube furnace equipped with a controlled atmospheric condition that functions as a calciner and a carbonator.X-ray diffraction and scanning electron microscopy with energy-dispersive x-ray spec-troscopy characterization were conducted to analyse the changes in the experimental samples.The results demonstrated that the reactor configuration was capable of performing the calcination process,which converted CaCO_(3) to calcium hydroxide[Ca(OH)_(2)],as well as the carbonation process,which captured carbon and converted it back to CaCO_(3).Parametric analysis was performed on both reactions,including pressure,temperature,duration,particle size and reaction atmosphere.The results show that the limestone obtained from all sites can be used as the sorbents for the calcium-looping process with an average reactivity of 59.01%.Limestone from cement plants in various parts of Indonesia has the potential to be used as carbon sorbents in calcium-looping technology.With a similar CO_(2) concentration as the flue gas of 16.67%,the experimental results show that Bayah limestone has the maximum reactivity,as shown by the highest carbon-content addition of 12.15 wt% and has the highest CO_(2)-capture capability up to>75% per mole of Ca(OH)_(2) as a sorbent.Similar levels of the ability to capture CO_(2) per mole of Ca(OH)_(2) can be found in other limestones,ranging from 14.85% to 34.07%.The results show a promising performance of raw limestones from different mining sites,allowing further study and observation of the possibility of CO_(2) emission reduction in the sustainable cement-production process.
基金
supported by Research and Community Service Program(P2MI)ITB.
