Square-Well Potential Equation of State for Computation of the Gas Hydrate Formation

Gas hydrates are undesired in natural gas processing and gas transportation pipelines. It is necessary to predict conditions of gas hydrates formation through thermodynamic modeling. The van der Waals Platteeuw model have been used for phase equilibrium calculation of gas hydrates so that the different equation of state are utilized for investigating hydrate equilibrium conditions.In this work, using the van der Waals Platteeuw model, the square well cubic equation of state [Haghtalab, A.; Mazloumi, S.H.; Fluid Phase Equilib. 2009, 280, 1-8] is applied for calculation of dissociation pressure of gas hydrates. The square well EOS is composed of van der Waals repulsive part and an attractive term which is based upon the square well potential using a new coordination number through Wilson local composition.The H-L-V equilibrium calculation was performed to optimization of the Langmuir constants against temperature for N2, CH4, C2H6, C3H8 and iC4H10 hydrates using the experimental data in literature. The results of the predicting of the square well EOS for the pure and gaseous mixture are in good agreement with the experiment. Also, the results of the present EOS are compared with the calculated values using SRK and PR EOSs.

کلیدواژه ها:

Gas Hydrate ، Square Well Equation of State ، van der Waals Platteeuw ، Langmuir Constants