A study of upgrading real biogas via CO₂ precipitation route under Indian Scenario

Our study focuses on upgrading real biogas obtained under Indian scenario using carbon capture and utilization (CCU) technology to remove carbon dioxide (CO₂) and utilize it by forming metal carbonate. Amines such as monoethanolamine (MEA), diethanolamine (DEA), and sodium hydroxide (NaOH) were used to rapidly convert gaseous CO₂ to aqueous CO₂, and BaCl2 was used as an additive to react with the aqueous CO₂ and rapidly precipitating the aqueous CO₂. All experiments were conducted at 25 °C and 1 atm. We analyzed the characteristics of the BaCO₃ precipitates using X-ray diffractometry (XRD), scanning electron microscopy - Energy dispersive spectroscopy (SEM-EDS) and Fourier-transform infrared spectroscopy (FT-IR) analyses. The precipitates exhibited witherite morphology confirmed by the XRD results, and FT-IR confirmed that the metal salt formed was BaCO₃, and EDS showed that there were no traces of impurities present in it. The quantity of the BaCO₃ was larger when formed with DEA. Also, a comparison was done with a previous study of ours conducted in Korean conditions. Finally, we observed that the carbonate obtained using real biogas showed similar properties to carbonates available in the market. An economic analysis was done to show the cost effectiveness of the method employed by us.