Prediction of hydrate formation for systems containing methanol

Abstract To reduce the risk of hydrate formation, methanol is the most commonly used inhibitor. A modified Peng—Robinson (PR) model based on Mollerup's random—nonrandom (RNR) theory was developed to describe the vapor—liquid equilibria of strongly polar methanol—water—gas systems under pressure. The new model (PR-RNR model), as coupled with the simplified version of the Holder—John three-shell hydrate equilibrium model proposed by the authors, has been successfully used to predict the effect of methanol concentration on hydrate formation of pure gases and gas mixtures.