To cite this article: Anuwattana, R., Phungngamphan, P. & Chawakitchareon, P. (2018). The efficiency of carbon dioxide and hydrogen sulphide adsorption using impregnated granular activated carbon and zeolite. J. Phys. Sci., 29(Supp. 3), 29–36, https://doi.org/10.21315/jps2018.29.s3.4
In this work, adsorbents granular activated carbon (GAC), granular activated carbon with acetylene (CVD/GAC) and zeolite A were applied for carbon dioxide (CO2) and hydrogen sulphide (H2S) gas removal. The adsorbents were characterised by scanning electron microscope (SEM) and X-ray diffraction (XRD). Polyethyleneimine (PEI) in ethanol with initial concentration of 0.2 g l–1 and 1 mol dm–3 lithium nitrate (LiNO3) were prepared to improve the adsorption capacity. In the impregnation process, various adsorbents, i.e., GAC, CVD/GAC and zeolite A were placed in a vial containing 0.2 g l–1 of PEI and 1 mol dm–3 of LiNO3 solution, at different ratios of adsorbent and various solutions of 30%W/W. The adsorbents (GAC, PEI/CVD/GAC:PEI/GAC, LiNO3/CVD/GAC:LiNO3/GAC, zeolite 5A, PEI/zeolite 5A and LiNO3/zeolite 5A) were tested by using the synthetic biogas (45% CO2, 10% N2, 45% CH4 and 105 mg dm–3 of H2S). The performance of CO2 and H2S adsorption results have shown that PEI/CVD/GAC is the best adsorbent for low concentration of H2S and LiNO3/5A is the best adsorbent for CO2 adsorption. The purity of the outlet methane was 96.6%, 97.3%, 98.1%, 81.53%, 80.6% and 93.6% for zeolite 5A, LiNO3/5A, PEI/5A, GAC, LiNO3/CVD/GAC and PEI/CVD/GAC, respectively. The selectivity in the H2S/CH4 ratio of GAC is higher than zeolite 5A. The adsorption selectivity of the CO2/CH4 ratio of LiNO3/5A is higher than GAC.