Phase equilibrium modeling of semi-clathrate hydrates of seven commonly gases in the presence of TBAB ionic liquid promoter based on a low parameter connectionist technique

Abstract

Several studies show that thermodynamic ionic liquid promoter, such as Tetra-n-butylammonium bromide (TBAB) can moderate the formation conditions of gas hydrates. In the current study, a Support Vector Machine (SVM) and coupling of SVM with Genetic Algorithm (GASVM) have been developed to predict semi-clathrate hydrate pressure of CO2, CH4, N2, H2, Ar, Xe and H2S in the presence of TBAB ionic liquid according to the critical temperature (Tc), critical pressure (Pc) and acentric factor (ω) of abovementioned gases over wide ranges of temperature, pressure and concentration of TBAB. For implementation of networks, 528 experimental data points collected from the published papers have been employed. Moreover, to verify both proposed models, regression analysis and statistical analysis such as mean square errors (MSEs), average relative deviations (ARDs), standard deviations (STDs) and root mean square errors (RMSEs) have been conducted on the experimental and predicted values of semi-clathrate hydrate pressure of gases in TBAB. While, the values of R2=0.97759 and ARD=0.25465132obtained for SVM model, coefficient of determination (R2) and Average Relative Deviation (ARD) of GASVM between the experimental and predicted values are 0.99944 and 0.07180737 respectively. Finally, according to the obtained results, in this contribution, ability and better performance of using GASVM as a correlation for prediction of semi-clathrate hydrate pressure and temperature in TBAB has been shown against SVM model.