1. Department of Applied Chemistry, Faculty of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan
2. Idemitsu Kosan Co. Ltd., 3-1 Nakasode, Sodegaura, Chiba 299-0267, Japan
3. Japan Coal Energy Center, 3-14-10 Mita, Minato, Tokyo 108-0073, Japan