(Special session) Recent trends in the development and utilization of coal and other energy resources［Thu. Sep 14, 2023 PM Room-3］

[3301-10-02] A laboratory study on improving coal permeability with NaOH to enhance CO₂ adsorption

○Theodora Noely Tambaria¹, Yuichi Sugai¹, Takehiro Esaki¹ (1. Kyushu University)

Keywords:Coal, CO2, Adsorption, Alkali, Permeability

The purpose of this study was to evaluate the effect of sodium hydroxide on increasing coal permeability to increase CO₂ adsorption capacity. The coal used in this study has low moisture content and high ash yield. The coal samples were dried and prepared into untreated coal samples that were then treated with sodium hydroxide at different concentrations (0.1 M, 0.5 M, 1M and 2 M) over a period of six hours. A volumetric apparatus was used to measure the amount of CO₂ adsorption on both untreated and treated coal samples in order to determine the effect of operating pressure on the amount of CO₂ adsorption. The coal sample is high rank coal, drying did not result in any significant changes, but after treatment with NaOH for 6 hours, the coal samples showed evidence of breakage, along with increasing NaOH concentrations. According to SEM results, untreated coal has minerals that fill up the pores, whereas treated coal has opened pores, created fractures, and a fracture network. In CO₂ adsorption experiments, the sample treated with NaOH exhibited an increase in CO₂ adsorption capacity with increasing concentration and pressure. Accordingly, the study indicates that coal treatment with NaOH increases CO₂ adsorption efficiency.