Soil with high porosity as an excellent carbon dioxide adsorbent carbon-rich soil as an effective adsorbent for carbon dioxide

Carbon dioxide, a type of greenhouse gases has drawn world wide's attention as major contributors to global warming and climate change. Thus, several methods have been developed to mitigate this problem such as through adsorption. There are numerous types of adsorbents available, for instance is carbon-based adsorbent that can be synthesised from various type of biomass as reported in previous studies. However, there are very few studies used soil as an adsorbent for gases. Soils are porous medium developed in the uppermost layer of Earth's crust which are available in several forms, abundance and cheap. In this study, three types of carbonised soils were used as carbon-based adsorbent to investigate its adsorption capacity for carbon dioxide. Influence of moisture content in this study is negligible as it is too low. Due to the nature of raw materials used, ash content for all sample was incredibly high which almost all exceeded 90%. Determination of densities by pycnometer showed that carbonised soil 2 has the lowest particle and bulk density of 2.4802 g/cm³ and 0.5248 g/cm³ respectively. Then the adsorption capacity of each sample was determined by sorption measuring instrument with magnetic suspension balance. Results showed that carbonised soil 2 with high surface area, pore volume, and small pore size has the highest adsorption capacity of 6.4 mg/g at 25 ˚C under atmospheric pressure. Therefore, soils exhibit prominent potential to be developed as carbon dioxide adsorbent with desirable properties.