Carbon dioxide hydrate inhibition by tetramethylammonium chloride + glycerol deep eutectic solvent

Abstract

Gas hydrate formation is undesirable in flow assurance processes, as their formation can lead to the clogging of pipelines. Additives can be added to oil and gas streams to act as thermodynamic or kinetic inhibitors. Most currently utilized additives are either toxic or environ mentally unfriendly. In a quest for more environmentally friendly alternatives, deep eutectic solvents (DES) were investigated in this study. Hydrate dissociation conditions for systems comprising water + carbon dioxide + tetramethylammonium chloride/glycerol were measured using the isochoric pressure search method. Temperatures ranging from 275 to 284 K and pressure ranging from 2 to 4 MPa were considered with deep eutectic solvent compositions from 10 to 20 wt %. The objective of this study was to analyze the efficiency of deep eutectic solvents as carbon dioxide gas hydrate inhibitors. The experimental data reported in this study indicated inhibitory effect,, depending on the concentration of the deep eutectic solvents used in this study. Experimental results are discussed in terms of the effect of the DES composition on the phase behavior under hydrate forming conditions. Data reported in this study can be used to develop thermodynamic models for DES containing systems, as well as to better understand the effect of the structure of deep eutectic solvents on gas hydrate formation.