1. Center for Refining and Petrochemicals, Research Institute, King Fahd University of Petroleum & Minerals; Dhahran 31261 Saudi Arabia
2. Dept. of Chemical Engineering; King Fahd University of Petroleum & Minerals; Dhahran 31261 Saudi Arabia
3. NMR Core Laboratory, King Abdullah University of Science & Technology; Thuwal 23955-6900 Saudi Arabia