1. Department of Chemical Engineering, Sciences and Research Branch, Islamic Azad University (IAU), Tehran, Iran, Gas Science Department, Gas Research Division, Research Institute of Petroleum Industry (RIPI), National Iranian Oil Company (NIOC), P.O. Box 14665-137, West Blvd. Azadi Sport Complex, Tehran, Iran, and Department of Chemical and Petroleum Engineering, Sharif University of Technology, Azadi Ave., Tehran, Iran