Mass Transfer Performance Study for CO<sub>2</sub> Absorption into Non-Precipitated Potassium Carbonate Promoted with Glycine Using Packed Absorption Column: Fid-Bau Portal

Mass Transfer Performance Study for CO₂ Absorption into Non-Precipitated Potassium Carbonate Promoted with Glycine Using Packed Absorption Column

Nur Farhana Ajua Mustafa / Azmi Mohd Shariff / Wee Horng Tay / Hairul Nazirah Abdul Halim / Siti Munirah Mhd Yusof

Abstract

The removal of carbon dioxide (CO₂) at offshore operation requires an absorption system with an environmentally friendly solvent that can operate at elevated pressure. Potassium carbonate promoted with glycine, PCGLY, is a green solvent that has potential for offshore applications. For high solvent concentrations at elevated pressure, the by-product of CO₂ absorption consists of precipitates that increase operational difficulty. Therefore, this study was done to assess the CO₂ absorption performance of non-precipitated PCGLY with concentration 15wt%PC+3wt%GLY, which is known to have comparable solubility performance with MDEA. A packed absorption column was used to identify the CO₂ removal efficiency, mass transfer coefficient in liquid film, $k_{l} a_{e},$ and overall volumetric mass transfer coefficient, $K_{G} a_{v}$ . A simplified rate-based model was used to determine $k_{l} a_{e}$ and $K_{G} a_{v}$ based on the experimental data with a maximum MAE value, 0.057. The results showed that liquid flow rates and liquid temperature gives significant effects on the $k_{l} a_{e}$ and $K_{G} a_{v}$ profile, whereas gas flow rate and operating pressure had little effect. The CO₂ removal efficiency of PCGLY was found to be 77%, which was only 2% lower than 1.2 kmol/m³ MDEA. $K_{G} a_{v}$ of PCGLY is comparable with MDEA. The absorption process using PCGLY shows potential in the CO₂ sweetening process at offshore.