Break down of waste materials such as animal parts is carried out by pyrolysis, gasification and combustion using a reactor vessel with a conical lower portion located within an exterior vessel. Feed material is deposited in continuous mode through an air lock at the top and falls by gravity alone into the lower cone portion. The cone geometry supports organic feedstocks, eliminating the requirement for grates or other combustion support systems. Organic material that may escape gasification and exit the bottom of the cone accumulates within the ash and carbon particle volume until burned. Carbon is sequestered from high energy feedstocks and is stored in a chamber below the gasification cone. This carbon supplements the energy output of lower energy feedstocks to maintain desired operating temperatures at all times.