Simulação computacional de líquidos de interesse em tecnologia limpa

Abstract

Since the ancient times the Earth has gone through several temperature changes, and these changes are closely linked to the concentration of greenhouse gases in the atmosphere. However, since the industrial revolution there was an exponential increase in emissions of greenhouse gases, thereby generating a temperature rise higher than expected. Several studies have been conducted to develop methods to capture those gases. One of typical methods presently used are aqueous solutions of monoethanolamine, however this technology has some disadvantages as a high environmental impact and high energy cost, thus new methods have been proposed. Ionic liquids (ILs) have been considered a promising technology for capturing CO2, which is one of the objects of study of this work. The effects of CO2 on the transport properties of the ionic liquid 1-Ethyl-3-methyl-imidazolium bis (trifluorsulfonil) imide ([C2mim] [Tf2N]) and the local environment of interaction of CO2 in LI was investigated. A fluidization was observed in the ionic liquid caused by the gas present between the cation and anion structures by providing a shielding effect on cation-anion interactions resulting in decreased interaction and increased mobility of species in the environment. The absorption of carbon dioxide by the monoethanolamine (MEA) is made through gas reaction with the amine grouping, and to facilitate exposure of this grouping can generate a better reaction kinetics. Thus, we studied in this work dilution of monoethanolamine in acetonitrile (ACN) in order to observe the decrease in the number of hydrogen bonds and increased exposure of the amine grouping. However, it was observed that dilution of monoethanolamine can enhance the intermolecular interactions and decrease the distances of the hydrogen bonds and therefore favor the gauche geometry of the molecule. Recent studies show that a larger population of MEA this geometry makes the basic system and consequently more favorable reaction with CO2.