Evaluation of various types equations of state on prediction of rate of hydrate formation for binary gas mixtures in the presence or absence of kinetic hydrate inhibitors in a flow mini-loop apparatus

Abstract

This paper compares the effects of using various types of equations of state (PR,11Peng Rabinson. PSRK,22Soave Ridlich Kowng. ER,33Esmaeilzadeh–Roshanfeker. NB44Nasrifar–Boland. and VPT55Valderrama-Patel–Teja.) for gas consumption during gas hydrate formation based on the Kashchiev and Firoozabadi model for binary gaseous mixtures such as 70% C1/30%C3, 30% C1/70% C3, 70% C1/30% i-C4, 30% C1/70% i-C4 with experimental data points obtained in a flow mini-loop apparatus in presence or absence of kinetic hydrate inhibitors at various pressures and specified temperature. A laboratory flow mini-loop apparatus is designed and built up to measure the gas consumption rate during gas hydrate formation.For the prediction of the gas consumption rate for double gas hydrate formation in a flow mini-loop apparatus, the rate equation based on the Kashchiev and Firoozabadi model for simple gas hydrate formation in batch system was developed. The total average absolute deviation was found to be 17.6%, 18.1%, 18.8%, 19.1% and 19.6% for the PR, NB, ER, PSRK and VPT equations of state for calculating gas consumption for binary gaseous mixtures during gas hydrate formation in the presence and absence of kinetic hydrate inhibitors, respectively. Comparison results between the calculated and experimental data points of gas consumption were obtained in flow loop indicate that the PR and NB equations of state have lower errors than the PSRK, ER and VPT equations of state for this model.