Influência da solubilidade do dióxido de carbono (CO2) em água na formação de hidratos

Abstract

Due to the intense release of CO2 into the atmosphere, many studies have been conducted in order to propose ways for removing it from the environment. One of these ways is the capture of CO2 in deep saline reservoirs. This gas is also responsible for clogging of lines and pipes due to hydrate formation during the extraction and transportation of natural gas and oil. The CO2 behaves as a guest molecule in the crystalline structure of hydrates, wherein the host lattice is composed of several water molecules linked by hydrogen bonds. This work aims to evaluate the behavior of the phase equilibria of CO2 and water system at different compositions in pressures ranging from 0.5 MPa to 6 MPa and temperatures of 275 K to 300 K. The experimental measurements were made using the synthetic static method without sampling phases, in a cell made stainless steel with piston. The theoretical model of solubility was implemented through the EES program to obtain the fugacity coefficient through the PR-EoS with the consideration that the mole fraction of water in the vapor phase (y2) at the time of appearance of the bubble can be neglected. Proposals considerations in this work showed a good agreement with the data taken from the literature and both the experimental methodology as the theoretical model were reliable. The theoretical model showed good results when compared with all three experimental compositions (x1 = 0,0058, x1 = 0,015 and x1 = 0,025).