Carbon Dioxide Absorption Using Different Solvents (MEA, NaOH, KOH and Mg(OH)2) in Bubble Column Reactor

Abstract

Carbon dioxide is considered to be one of the greenhouse gases potentially responsible for climate change. The aim of this research is to reduce emissions by capturing carbon dioxide in a solution using an absorption method. The absorption capacity, absorption rate, carbon dioxide removal efficiency, and overall mass transfer coefficient of MEA (Monoethanolamin) and alkaline solvents (NaOH, KOH, Mg (OH)2) were investigated using a bubble column gas absorption reactor with counter current flow. The effects of operational parameters such as solvent concentration (0.01, 0.05, and 0.25M) and solvent type were studied. The research showed that KOH, NaOH, and MEA were more efficient in capturing CO2 than Mg (OH)2 was. For all solvent types, the total mass transfer coefficient, absorption rate, and CO2 removal efficiency were increased with the increase in the concentration of solvent. The solvent concentration is increased from 0.01 M to 0.25 M to obtain the highest KGa values for MEA, NaOH, and KOH, 3.75 1/min for MEA, 3.70 1/min for NaOH, and 3.93 1/min for KOH.The MEA, NaOH, and KOH absorption rates were maximum at 0.25 M solvent concentrations as 0.19x103 mol/Ls. The maximum CO2 removal efficiencies for MEA, NaOH, and KOH at 0.25 M solvent concentration are greater than 60%. Absorption capacity of NaOH and KOH is 0.313 mol CO2/mol NaOH and 0.316 (mol CO2/mol KOH). The highest absorption capacity, 0.576 mol CO2/mol MEA, was obtained at a solvent concentration of 0.01M MEA.