Abstract: Nongaseous carbonaceous material is heated by a method comprising introducing tangentially a first stream containing a nongaseous carbonaceous material and carbon monoxide into a reaction zone; simultaneously and separately introducing a second stream containing oxygen into the reaction zone such that the oxygen enters the reaction zone away from the wall thereof and reacts with the first stream thereby producing a gaseous product and heating the nongaseous carbonaceous material; forming an outer spiralling vortex within the reaction zone to cause substantial separation of gases, including the gaseous product, from the nongaseous carbonaceous material; removing a third stream from the reaction zone containing the gaseous product which is substantially free of the nongaseous carbonaceous material before a major portion of the gaseous product can react with the nongaseous carbonaceous material; and removing a fourth stream containing the nongaseous carbonaceous material from the reaction zone.