ASSESSING THE OPERATIONAL LIMITS OF THE INTENSIFICATION OF CARBON CAPTURE BY ALKALINE SOLUTIONS

Abstract

Carbon capture is one of the techniques for reducing the impact of greenhouse gas emissions on the environment. Several carbon capture methods have been developed and are constantly being improved and optimized, but the most promising appears to be that involving a chemical reaction. This study focuses on testing the limits of intensifying the chemical absorption of CO2 into a NaOH aqueous solution. To accomplish this, various process parameters were altered including the pH of the solvent, total superficial liquid and gas velocities and the CO2 content of the gas stream.

The efficiency of the reactor in removing carbon dioxide was determined by calculating the CO2 removal efficiency, the specific energy consumption of the operation, and by comparing it to the physical absorption of CO2 in water under similar hydrodynamic conditions. The removal efficiency of CO2 was measured along the length of the reactor and was found to increase with the increase in either total superficial velocity, CO2 concentration in the gas phase or NaOH concentration in the liquid phase. Efficiencies as high as 91.4% were recorded at the cost of 148.65 kWh/tonne-CO2. The results were found very promising for further optimization of the process.