This document is an expanded abstract.
Summary
Polyethers are a family of compounds of interest for the oil industry: glycols are known by their application as dehydration agents while glymes have gained the interest from both industry and academia as feasible candidates for gas separations. However, their characterization is still poor, hindering the development and optimization of novel separation processes. This work aims at demonstrating the soft-SAFT reliability that, when combined with a limited number of experiments, can provide a way for systematic studies on the performance of physical solvents for gas processing technologies. A recently developed, consistent, reliable and transferable molecular model for polyethers in the framework of soft-SAFT, is here applied for the first time to model the vapor-liquid equilibria (VLE) of glymes + CH4/CO2. Moreover, the same model is shown to be able to accurately describe the VLE of aqueous solutions of polyethers.
Introduction
Given the world’s population growth and consequent increase on the global energy demand, the Oil & Gas industry plays a vital role in today’s society, not only because oil and gas are important energy sources but also because they serve as feedstocks for a wide number of industries. On the other hand, the environmental impact driven by their activities establishes an endless demand for cleaner and more efficient technologies that can result in the development of low-cost plants of reduced emissions, weight and energy consumption. The development and optimization of such technologies is a demanding but inspiring task, closely tight to the development of novel solvents for gas separations and, consequently, to an accurate understanding of the sorption and permeation mechanism of the reservoir gases.
Raw natural gas is much different than end-use natural gas, which is composed almost entirely by methane (CH4). Regardless of the natural gas source, methane is generally present in a hydrocarbons mixture (mainly C2 to C5) along with water vapor, carbon dioxide (CO2), hydrogen sulfide (H2S), nitrogen (N2) and other gases. Therefore, and prior to distribution, the gas needs to be processed, aiming at the removal of the different gases and hydrocarbons from CH4 to meet the required pipeline specifications.
