THE EFFECT OF VARIOUS TYPES OF EQUATIONS OF STATE ON DRIVING FORCE CALCULATION AND GAS CONSUMPTION PREDICTION IN SIMPLE AND DOUBLE HYDRATE FORMATION WITH OR WITHOUT THE PRESENCE OF KINETIC INHIBITORS IN BATCH SYSTEMS

Abstract

This article compares the effects of using various types of equations of state (Peng-Robinson, PR; Soave-Redlich-Kwong, SRK; Esmaeilzadeh-Roshanfekr, ER; Patel-Teja, PT; and Valderrama-Patel-Teja, VPT) on the calculated driving force and rate of gas consumption based on the Kashchiev model in simple and double-gas hydrate formation for methane, ethane, and their mixtures with 1130 experimental published data points with or without the presence of kinetic inhibitors at various pressures and temperatures. For the prediction of gas consumption rate in double-gas hydrate formation, the rate equation based on the Kashchiev model for simple gas hydrate formation was developed using the calculation of gas mole fraction in hydrate phase and then prediction of gas hydrate formation rate for each component in gaseous mixture. The total average absolute deviation was found to be 8.72%, 10.34%, 8.84%, 11.04%, and 14.16% for the PR, ER, SRK, VPT, and PT equations of state for calculating gas consumption in simple and double hydrate formation, respectively.

Keywords:

• Double hydrate formation
• Driving force
• Equation of state
• Gas consumption rate
• Inhibitors
• Kashchiev model

Acknowledgment

The authors are grateful to the Shiraz University, Fars Technological and Environmental Research Center and International Iranian Gas Company for supporting this research.

Notes

m = 1/2 for without inhibitor and m = 1/3 with inhibitor, wetting angle = 60°, σ = 20 mJ/m² (Kashchiev and Firoozabadi, 2003).

^a % ADDY = 100/n .

^b Experimental data is from Makogon (1997).

^c Experimental data for nos. 2 − 27 is from Englezos et al. (1987a).

^d Experimental data is from Monfort et al. (2000).

^e In presence of kinetic inhibitor (0.05 wt.%; VC 713); experimental data from Monfort et al. (2000).

^f In presence of kinetic inhibitor (0.05 wt.%; PVP k15); experimental data from Monfort et al. (2000).

m = 1/2 for without inhibitor and m = 1/3 with inhibitor, wetting angle = 60°, σ = 20 mJ/m² (Kashchiev and Firoozabadi, 2003). Reference for experimental data without presence of kinetic inhibitor: Englezos et al. (1987b).

^a % ADDY = 100/n .

^b In presence of kinetic inhibitor (Monfort et al., 2000).