Calcium alginate gel and hard beads for the removal of total organic acid anions and heavy metal ions from industrial lean methyldiethanolamine solvent

摘要

Bio-polymeric adsorbents such as calcium alginate gel (CAG) and hard (CAH) beads were prepared to remove both the total organic acid anions (formate, acetate, propionate, etc.) and the heavy metal ions (chromium and iron) simultaneously from industrial lean methyldiethanolamine (MDEA) solvent used in the natural gas sweetening industry. These are undesirable products accumulated in the process which leads to solvent losses and contribute operational problems such as corrosion, fouling and foaming. The adsorbents were characterized using TGA, FTIR and SEM analyses. Kinetic and equilibrium studies at different temperatures including regeneration of the adsorbents were carried out. The maximum uptake capacity for the total organic acid anions using the CAG and CAH adsorbents at 23 degrees C was found to be 322.58 and 19.72mg/g, respectively. Based on the high uptake, feasibility and recyclability, calcium alginate beads exhibit a great potential for MDEA solvent purification.