F23B—METHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
F23B90/00—Combustion methods not related to a particular type of apparatus
F23B90/04—Combustion methods not related to a particular type of apparatus including secondary combustion
F23B90/06—Combustion methods not related to a particular type of apparatus including secondary combustion the primary combustion being a gasification or pyrolysis in a reductive atmosphere