Patent ID: 8153027

Claim:
A method of forming syngas, said method comprising the steps of: (a) devolatilizing a carbon-containing feed material to form a gas phase and a solid phase in a devolatilization unit, wherein said devolatilization unit includes a cascading series of devolatilization chambers with augers for conveying said carbon-containing feed material through said devolatilization chambers at increasing temperatures; and (b) passing said gas phase and said solid phase through a heated reaction vessel to form syngas, wherein said heated reaction vessel includes a cold chamber; a hot chamber separated from said cold chamber; a reaction tube traversing through said cold and hot chambers; a primary cyclone, connected to said reaction tube, for removing ash; and a polishing cyclone, connected to said primary cyclone, for removing additional ash; wherein step (a) is performed in the presence of free oxygen in an amount between about 0.5% and about 25% of the stoichiometric amount of oxygen to completely combust said feed material; wherein the temperature of said heated reaction vessel is controlled to be above the dew point of said gas phase from said devolatilization unit; and wherein a portion of said syngas is recycled back to said devolatilization unit.