Determination of dissolved CO₂ concentration in culture media: Evaluation of pH value and mathematical data

Carbon dioxide is the most influential gas in greenhouse gasses and its amount in the atmosphere reached 412 µmol/mol in August 2020, which increased rapidly, by 48%, from preindustrial levels. A brand-new chemical industry, namely organic chemistry and catalysis science, must be developed with carbon dioxide (CO₂) as the source of carbon. Nowadays, many techniques are available for controlling and removing carbon dioxide in different chemical processes. Since the utilization of CO₂ as feedstock for a chemical commodity is of relevance today, this study will focus on how to increase CO₂ solubility in culture media used for growing microbes. In this work, the CO₂ solubility in a different medium was investigated. Sodium hydroxide (NaOH) and monoethanolamine (MEA) were added to the culture media (3.0 g/L dipotassium phosphate (K₂HPO₄), 0.2 g/L magnesium chloride (MgCl₂), 0.2 g/L calcium chloride (CaCl₂), and 1.0 g/L sodium chloride (NaCl)) for growing microbes in order to observe the difference in CO₂ solubility. Factors of temperature and pressure were also studied. The determination of CO₂ concentration in the solution was measured by gas analyzer. The result obtained from optimization revealed a maximum CO₂ concentration of 19.029 mol/L in the culture media with MEA, at a pressure of 136.728 kPa, operating at 20.483^◦C.