Enhancing CO₂ Adsorption via Amine-Impregnated Activated Carbon from Oil Sands Coke

In this work, amine-impregnated activated carbon was prepared from oil sands coke, for use in CO₂ capture. Delayed oil sands coke was activated using microwave heating and KOH as activation agent. The resulting material was then impregnated with one of diethanolamine, methyl diethanolamine, or tetraethylene pentamine. Analysis of the bulk and surface composition of the impregnated samples using elemental analysis and X-ray photoelectron spectroscopy suggested that the amines were deposited on the surface of the activated carbon. Materials impregnated with diethanolamine performed best for CO₂ capture; the highest adsorption capacity achieved was 5.63 mmol CO₂/g adsorbent for activated carbon impregnated with 1.15 mmol N/g activated carbon - nearly 75% higher than reported values for zeolite 13X. Adsorption of CO₂ on the amine-impregnated activated carbon at 40, 50, 60, and 75°C showed that the highest adsorption capacity was obtained at 50°C. Using oil sands delayed coke as a precursor for activated carbon transformed a petroleum waste material into an effective CO₂ adsorbent. Modifying the prepared activated carbon with amines improved CO₂ uptake capacity, creating a useful adsorbent for potential use in CO₂ capture.