Patent ID: 7185595

Claim:
A method for combusting a fuel comprising at least eighty percent petroleum coke comprising the steps of: introducing a stream of primary air and the fuel comprising at least eighty percent petroleum coke into a combustion zone comprising a furnace which comprises a horizontally-fired burner having a position at an angle from coincident with a horizontal axis of the furnace un to an angle of 45 degrees to the horizontal axis of the furnace; simultaneously introducing one or more of secondary, tertiary, or quaternary air proximate said stream of primary air and the fuel as said stream of primary air and the fuel enters said combustion zone; optionally introducing over-fire air at a location above said combustion zone; introducing substantially pure oxygen into or proximate one or more of said stream-of primary air and the fuel as said stream of primary air and the fuel enters said combustion zone, said secondary air, said tertiary air, said quaternary air or said over-fire air, said substantially pure oxygen introduced in an amount to raise overall oxygen concentration to from 0.58% a by volume to a maximum of 10% a by volume greater than when combusting said fuel using only air as a source of oxidant; and recovering fly ash from said combustion zone for re-use as a fuel source.