1. Instituto de Carboquímica, (CSIC), C/Miguel Luesma Castán No. 4, 50015, Zaragoza, Spain, Instituto Nacional del Carbón, (CSIC), C/Francisco Pintado Fe, No. 26, 33011 Oviedo, Spain, and CANMET Energy Technology Centre-Ottawa, Natural Resources Canada, 1 Haanel Drive, Ottawa, Ontario, Canada K1A 1M1