Study of Carbon Dioxide Absorption Process by Mixtures of Monoethanolamine(MEA) and Triethanolamine(TEA) in the Presence of Carbon Nanotubes(CNT)

There are various technologies being used to separate CO2 from the flue gas of conventional fossil fuel fired power plants, e.g. chemical absorption, physical absorption, membrane separation and biological fixation. Chemical absorption, is generally recognized as the most effective technology among all the technologies at present[1].The most well-stablished method for CO2 capture is to remove CO2 by absorption into amine solutions in conventional equipment. Amines are weak basic compounds that react with CO2 to form weak chemical bonds. These chemical bonds are easily broken upon mild heating, leading to regeneration. Although chemical absorption technology has important commercial significance, judicious selection of a competitive absorbent that is capable of high CO2 loading, rapid absorption rate and low cost for regeneration remains a challenge[2]. The absorption of acid gases in mixed amines has specific advantages over the use of single amines. The addition of a small amount of primary amine to conventional tertiary amines can enhance the rate of absorption of CO2 to a large extent without appreciably affecting the stripping characteristics. By varying the relative concentrations of the amines, an optimum absorption system can, in principle, be designed for a specific application[3]. In this research, CO2 absorption experiments were carried out at various amine concentrations and blends in the presence and absence of carbon nanotubes at low CO2 partial pressures in an absorption cell. The partial pressure and the gas flow rates has been changed in the range of 10-70 kPa and 40-120 cm3/min, respectively. The temperature of experiments was constant at 40oC