Effect of binder ratio on the physical properties of porous carbon pellet for CO₂ capture

The purpose of this work was to investigate the effect of binder ratio on the physical properties of carbon-based pellets in capturing CO₂. The influence of the binder materials was also examined to compare the pellet quality. To make good-quality carbon pellets, tapioca starch (TS) and xanthan gum (XG) were used as organic binders and mixed with activated carbon to form pellets. The physical properties of the carbon pellets were analyzed using different analytical methods: Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), Thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR). In addition, the CO₂ adsorption performance of the carbon pellets was investigated by evaluating their adsorption capacity and CO₂ breakthrough characteristics. The results revealed no significant changes to the pore development of the carbon pellets after the CO₂ adsorption. However, the EDX results for the carbon pellets using the starch binder showed an increase in the oxygen content after the CO₂ adsorption. With the addition of water and the binder, both types of carbon pellets (TS-AC and XG-AC) still produced high carbon content. Interestingly, the carbon pellets using the low-cost binder (tapioca starch) shows high performance than xanthan gum binder due to has numerous functional groups, longer breakthrough time and high CO₂ adsorption capacity. The TS-AC carbon pellets exhibited a remarkably high breakthrough time and CO₂ adsorption capacity of 16.2 min and 21.84 mg/g at 25 °C.