Thermo-chemical transformation of wet food waste with plastics, biodegradable packaging, and fluorinated compounds in a multi-annular concentric feed rotary kiln system

Abstract

The invention relates to a system and process for thermo-chemical transformation of mixed wet waste streams using a rotary kiln reactor equipped with a multi-annular concentric feed assembly. A central conduit introduces wet food waste mixed with plastics, biodegradable packaging, and fluorinated materials, while an intermediate annulus supplies auxiliary fuel and an outer annulus delivers oxidant gas under controlled sub-stoichiometric conditions. The kiln operates through sequential zones of reduction, partial oxidation, and complete oxidation to convert organics into hydrogen, carbon monoxide, methane, and finally carbon dioxide and water. Halogens and sulfur compounds are converted to hydrogen halides and hydrogen sulfide, which are neutralized downstream with calcium oxide to form stable salts. Heat recovery from the flue gas produces steam or hot water. The process eliminates pre-drying, allows co-processing of wet and dry wastes, and provides efficient energy recovery in a compact, scalable configuration. The invention eliminates the need for pre-drying or segregation, enabling simultaneous treatment of heterogeneous feedstocks.