On the coprocessing of coal with natural rubber or butadiene rubber, the yield of residue was higher than the yield calculated from those individual liquefaction, because the polymerization between rubber and coal occurred. On the coprocessing of higher rank coal (Huaipei coal) and styrene-butadiene rubber (SBR), the yield of residue was lower than the calculated yield, because the polyaromatic compounds derived from SBR acted as a hydrogen shuttling solvent.
