Liquefaction of Tanito Harum coal with bottom recycle using FeNi and FeMoNi catalysts supported on carbon nanoparticles

Bottom recycling liquefaction of an Indonesian sub-bituminous Tanito Harum coal was performed to maximize the oil yield and catalyst utilization using FeNi and FeMoNi catalysts supported on carbon nanoparticles for single- and two-stage processes. Two procedures of bottom recycle were carried out: the first procedure (procedure 1) was to recycle crude liquid bottom without additional fresh catalyst, while the second procedure (procedure 2) was to make up recycling feed by purging a part of the bottom and adding fresh catalyst. At the same amount of the total catalyst, the second procedure was found to provide more oil yield than the first procedure, suggesting that the catalyst should be deactivated. High recycle ratio provided excellent oil yield over 74% with successful reduction of catalyst amount to 1 wt.% d.a.f. coal base. Two-stage liquefaction with bottom recycle gave oil yield as high as 82% with a half amount of the fresh catalyst required for the liquefaction without bottom recycle. Higher catalytic activity of FeMoNi/Ketjen Black (KB) provided the higher oil yield with less amount catalyst at smaller catalyst recycle ratio compared to FeNi/KB catalyst.