Solubility of carbon dioxide using aqueous NPK 10:26:26 complex fertilizer culture medium and Spirulina platensis suspension

• CO2 solubility.
• Zarrouk culture medium.
• NPK 10:26:26 complex fertilizer.
• Microalgae.
• Spirulina platensis.

The present paper deals with the experimental results for carbon dioxide (CO2) absorption in aqueous blend of NPK 10:26:26 complex fertilizer, sodium chloride (NaCl), sodium hydroxide (NaOH) and Spirulina platensis using pure CO2 at temperatures ranging from 303 K to 318 K under atmospheric pressure. Concentration of NPK fertilizer and algae were varied in the neighborhood of maximum S. platensis growth whereas NaOH loading was adjusted to obtain the desired carbonate/bicarbonate concentration and pH in the culture medium. A fixed amount of NaCl was added to maintain the desired salinity of the culture medium. A sintered disk jacketed glass chromatographic column was used to increase gas–liquid contacting area for quick attainment of CO2 absorption equilibrium. The solubility of CO2 gas increased with the increased concentrations of NaOH at fixed CO2 partial pressure and temperature whereas CO2 solubility decreased with increased concentration of NPK-fertilizer and microalgae for given NaOH loading. CO2 solubility in NPK-fertilizer and microalgae suspension decreased with the increasing temperature under atmospheric condition. The experimental results of CO2 solubility in the present study were compared with aqueous blend of Zarrouk culture medium and S. platensis suspension.