Evaluating the Suitability of CaO as a Cloud Seeding Agent for CO2 Pollution Mitigation: A Simplified Experiment

Carbon dioxide (CO2) emission from wildfires accounts for almost 30% (0.44 Gt CO2eq) of Indonesia’s CO2 emissions in 2020. It is known that CO2 undergoes a reversible carbonation with calcium oxide (CaO) to form calcium carbonate (CaCO3) in CaO outer surface. Therefore, CaO has the potential to be a cloud seeding agent for CO2 pollution mitigation, potentially reducing CO2 emission in areas seeded with CaO. However, there is limited literature on the suitability of CaO as a seeding agent for CO2 pollution mitigation. Here, we conducted a series of carbonation reactions between CaO powder and CO2, with a mass ratio of 1:1, respectively. The experiments were conducted in a sealed box under room temperature and one atmosphere to limit the reaction area while mimicking external environment conditions. The experiments’ purpose was to determine the suitability of two types of CaO, a home industry-produced and a commercially produced one, as seeding agents for CO2 pollution. This was done by first measuring the sample’s before and after reaction daily changes in CO2 concentrations and CaO mass. Scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS) were used to characterize the microscale morphology and compositions of the two CaO after reaction. The results showed that commercially produced CaO is more reactive with CO2 than home-produced ones. In addition, home-produced CaO has a higher oxygen and lower calcium content than commercially produced ones. Commercial CaO powder is thus more effective than home-produced ones as a seeding agent to mitigate CO2 pollution.