Phase Equilibrium Modeling of Structure H Clathrate Hydrates of Methane plus Water Insoluble Hydrocarbon Promoter Using QSPR Molecular Approach

In this communication, the quantitative structure property relationship (QSPR) strategy is applied to present two molecular models for determination of the structure H (sH) hydrate dissociation conditions with methane as help gas. Twenty-one water insoluble hydrocarbon promoters are examined. To propose reliable models, almost all of the available literature data are studied. Two mathematical methods including the genetic-algorithm-based multivariate linear regression (GA-MLR) and the least square support vector machines (LSSVM) are applied for determination (selection) of the model parameters. As a result, two reliable models are developed: (1) QSPR-GA-MLR linear model and (2) QSPR-LSSVM nonlinear model with satisfactory results quantified by the following statistical parameters: absolute average deviations (AAD) of the represented/predicted hydrate dissociation pressures from existing experimental values: about 9%, and squared correlation coefficient: 0.956 in the case of using the first model, and about 4% and 0.992 through applying the second model, respectively. These results demonstrate much better accuracy through the QSPR-LSSVM nonlinear model than applying the QSPR-MLR linear one.