An ASG system for polygeneration with CC includes a devolatilizer that pyrolyzes solid fuel to produce char and gases. A burner adds exothermic heat by high-pressure sub-stoichiometric combustion, a mixing pot causes turbulent flow of the gases to heat received solid fuel, and a riser micronizes resulting friable char. A devolatilizer cyclone separates the micronized char by weight providing micronized char, steam and gases to a gasifier feed and oversized char to the mixing pot. An indirect fluid bed gasifier combustion loop includes a gasifier coupled to the gasifier feed, a steam input to provide oxygen for gasification and to facilitate sand-char separation, and an output for providing syngas. A burner provides POC to a mixing pot which provides hot sand with POC to a POC cyclone via a riser, where the POC cyclone separates sand and POC by weight and provides POC and sand for steam-carbon reaction.