Is provided a method for starting up a pressurized fluidized bed incinerator system by which cracking of silica sand as a bed material can be prevented at low costs. By heating the silica sand as the bed material filled up in a bottom portion of a pressurized fluidized bed incinerator, a temperature of a freeboard of the incinerator is heated, and after the temperature of the freeboard is heated to 750 to 900 C., a material to be treated having a water-containing organic substance is fed to the pressurized fluidized bed incinerator.

A reactor system includes a fluidized-bed. A fuel and a sulfur absorbent material are eluted through the fluidized-bed. The reactor system may include a heat exchanger having a heat-exchanging portion within a heating zone of the reactor that is hermetically sealed from the heating zone. The reactor may include loose particles of an inert bed material for forming the fluidized-bed. A feed system may be provided to inject a solid fuel composite that includes a mixture of a solid, carbonaceous fuel and a solid reagent into the reactor.

A reactor system includes a fluidized-bed. A fuel and a sulfur absorbent material are eluted through the fluidized-bed. The reactor system may include a heat exchanger having a heat-exchanging portion within a heating zone of the reactor that is hermetically sealed from the heating zone. The reactor may include loose particles of an inert bed material for forming the fluidized-bed. A feed system may be provided to inject a solid fuel composite that includes a mixture of a solid, carbonaceous fuel and a solid reagent into the reactor.