Análises termogravimétricas e físico-químicas visando descrever os efeitos térmicos da decomposição do monoetilenoglicol em meio aquoso salino

Abstract

On the step of oil transportation, It may occur the formacion of gas hydrates, this formacion occur at temperatures inferior of 30 °C and pressures superior than 20 bar. When exist the presence of hydrates on the tubulation,occur obstruction on the parcial or total form, compromissing the performance of the operation, because of that, knoing the losses that the hydrates may cause on the line of operation, it have been adopted the uses of thermodynamic inhibitors, the most used is monoethyleneglycol, because it is less harmful to the enviroment and of easy recovery, it works changing the curve of balance, avoiding the formation of hydrates. To make the use more economic viable and with less agression to the enviroment, that’s why the regeneration of meg, even thought, there is no knowledge of how many times the regeneration may occur with the same sample of meg. Having that on mind, the study of decomposion of solucions sodium chloride at a porcention bettewen 0 to 5 % and carbonate as an objective to this research. The methodology used to realize this study consist by heat the solucion prepared with MEG (poor) in a modified Othmer ebulliometer, heating the solucion for 56 hours and removing an aliquot to characterize it every 4 hours, by the end of the characterization the volume resting was returned to the ebulliometer by the end to avoyd a big lost of mass. To the characterization of this samples, there were made analysis of density, conductivity, pH, differential scanning calorimetry (DSC) and termogravimetry (TG). It was observed that systems without concentration of sodium chloride, with 44 hours of heating there are the presence of evidence of the decomposion from the MEG. To systems with 1 % of sodium chloride, this time is reduced to 32 hours, when this concentracion gets up to 3%, the decomposion become more evident after 16 hours of heat. Even though systems with 5 % of salt, with 8 hours of heart, we already have signals of decomposion. It can be explayned because of the way that the salt works, helping the decomposion, becoming an intensifier to it may occur.