A rotary cascading bed combustion system for converting waste product into energy includes a rotary cascading bed combustor boiler including a rotating cylinder surrounding a combustion chamber; the rotating cylinder being structured and disposed for cascading the fuel to facilitate the mixing of air and solids, wherein the rotational speed of the rotating cylinder is selectively varied based on the amount of fuel, airflow and combustion properties; wherein combusting waste is mixed with sorbents and cycled through a plurality of combustion zones to produce controlled heat for generating steam; wherein the steam is routed to a turbine; and wherein if carbon burnout is not complete it will be recycled back into the combustion chamber.

This invention provides a system and method for efficiently and completely combusting oil in mixture with particulate solids. A furnace (kiln) having a feed nozzle with a lead screw drives the mixture from a feed hopper. This nozzle includes forced-air jets/ports at its tip providing makeup air and allowing atomization of the mixture. The nozzle thereby directs the mixture into a rotating combustion chamber that is tilted downwardly from the front toward a solid waste outlet port at the rear. Uncombusted fuel and air backflow to an upper, secondary chamber near the primary chamber front, and are completely combusted at a high temperature. Gasses exit a flue that can include a heat exchanger. This heat exchanger can be operatively connected to a heating device or other mechanism that converts the heat into usable energy. The nozzle can include a cone with axially tilted air ports about its perimeter.

The present invention relates to a rotary kiln made of a metal alloy. The alloy is preferably chosen from the group of Alloy 321, Alloy 321H, Alloy 347, Alloy 347H, Alloy 348 and Alloy 348H. An object of the present invention is to provide a rotary kiln that can be operated under the reducing gas conditions to be experienced by the kiln in a pyrolysis process of scrap rubber. The present invention furthermore relates to the use of such a rotary kiln in a process for the pyrolysis of tyres.