Reactive absorption of CO₂ into the solution of methyldiethanolamine effect of promoter content in packed column

Carbon dioxide has many benefits such as in the production of dry ice, fire fighting, welding, and the production of carbonated drinks. As a result of these, it is important to develop a method to capture it effectively by reactive absorption using tertiary amine compounds, methyldiethanolamine (MDEA). Compared to primary and secondary amines, tertiary amines are inexpensive with a higher absorption capacity ratio of 1:1 (1 mole of CO₂/1 mole of MDEA). One of its demerits is its slow absorption rate which can be improved by adding diethanolamine (DEA) and glycine as promoters. The purpose of this research is to determine the effect, type and concentration of promoter, its absorbent flow rate and solution temperature on CO₂, as well as its removal percentage using a packed column filled with raschig ring. The concentration of CO₂ gas absorbed was examined using an analyzer. The equipment used consists of columns with a diameter of 2", column height of 80", and filled with 1/4" type raschig ring. Mixture of gases (10 % CO₂, 90 % air) is flowed into the column using a predetermined flow rate. The 40 % MDEA absorbent varies with the glycine and DEA promoter concentration and the absorbent flow rate also varies from 0.20 to 0.60 L/min. The promoter concentration varies from 0 (no promoter) to 5 % while the MDEA inlet solution temperature varies from 40°C to 60°C. Based on the analysis, the best operating conditions for CO₂ absorption using a DEA promoter of 3 % at 40°C with a flow rate of 0.20 L/min showed CO₂ removal of 42.7 %.