Preparation of commercially applicable slurry fuels from rapid hydrogasification char by blending with coal

• Rapid hydrogasification chars (RH chars) were enriched with micropores and capillary pores.
• RH chars had high holding capacities of water, particularly capillary water.
• RH chars showed the very poor slurryability and unique rheological behavior.
• An applicable water slurry was prepared by blending RH chars with a raw coal.
• An interactive effect between RH char and raw coal could promote the slurryability of blend.

The purpose of this work is first to investigate the slurryability of two chars produced from the rapid hydrogasification of two bituminous coals (YY coal and FG coal) in a pilot-scale entrained flow gasifier (abbreviated as RH char). Results showed that both RH chars had very poor slurryability mainly owing to the microporous and capillary structures of particles and the high water holding capacity, in sharp contrast to the properties of the parent coals and the char obtained from a common slow pyrolysis. The work thereafter aims at making a commercially usable water slurry by using the blends of RH char and YY coal. The slurry containing an adjusted solid blend of 60% total solid weight loading with 0.5% naphthalene sulfonate formaldehyde dispersant showed all satisfactory performances in the apparent viscosity, fluidity and static dispersion stability. Furthermore, it was found that the slurryability could be improved by an interactive effect between RH char and raw coal, which depended on the blending pairs and blending proportions.