“…The activity of carbonate and bicarbonate ions is dependent on the dissolution of CO 2 (g) and the pH of solution. Previous researchers have utilized buffers such as sodium bicarbonate, and bases such as potassium or sodium hydroxide, to adjust the pH and therefore control the speciation of carbonic acid [32]. Accordingly, experimentation was carried out with distilled water and various reagents using the Parr reactor, under CO 2 pressures ranging from 0.35 to 3.8 MPa.…”