Abstract: The present invention is a process and associated apparatus for obtaining energy from a fuel source having particles varying in size from fines to coarse. The fuel source is introduced into a passageway formed between an upper combustor and a lower combustor. A gas stream is moved upwardly through the passageway such that the fine particles are entrained in the gaseous stream and carried into the upper combustor.

Abstract: A low BTU, low volatile content, low carbon and high ash fuel is combusted in a combined shaft kiln combustor and fluidized bed combustor to generate heat which is converted to useful energy. The fluidized bed combustor is mounted vertically above the shaft kiln combustor. A venturi is provided in a passageway connecting the shaft kiln combustor and the fluidized bed combustor to produce a gaseous stream moving at a velocity sufficient to separate finer particles from the low BTU, low volatile content, low carbon and high ash fuel so that the coarser particles are burned in the shaft kiln combustor and the finer particles are burned in the fluidized bed combustor.

Abstract: A method for desulfurization, denitrification, and oxidation, of carbonaceous fuels including a two stage oxidation technique. The carbonaceous fuel, containing ash, along with an oxygen-containing gas is introduced into a first stage partial oxidation unit containing a molten ash slag maintained at a temperature of about 2200.degree.-2600.degree. F. A flux may also be introduced into the first stage partial oxidation unit for the purpose of increasing the basicity and maintaining the viscosity of the molten ash slag at a value no greater than about 10 poise. The carbonaceous fuel is gasified, and sulfur is chemically bound and captured in the molten ash slag. Since the first stage is operated in a gasification mode (reducing atmosphere), essentially all of the nitrogen in the fuel is converted to diatomic nitrogen, which results in low nitrogen oxide emissions upon final combustion.

Abstract: A coal conveyor capable of transporting pulverized coal to a higher pressure zone. The conveyor comprising an upright pressure vessel and a feed pipe extending into and between two endless conveyor belts located within the vessel which mesh during their descent to form a first and second pressure seal before the discharge of the coal into the higher pressure zone.