Abstract: An improved liquid hydrocarbon feed method is disclosed wherein substantially all of the liquid is converted to mist sized particles over a wide angled dispersion pattern without a concurrent shroud of steam or water. Such dispersion promotes vapor phase catalytic reaction between hydrocarbon vapors and fluidized catalyst in a reaction time of 1 to 3 seconds. The misting nozzle is characterized by a swirl chamber to which the full hydrocarbon feed, with or without steam included in the feed, is supplied for centrifugal rotation by vane members to form a free vortex. The flow is then released through a reduced area square-edge orifice having a short throat to form and maintain a characteristic "vena contrata" from such an orifice during flow into the catalyst stream in the riser reactor for dispersion over a wide angled conical dispersion pattern. Such flow from the orifice allows the nozzle to be recessed out of the flowing catalyst stream.

Abstract: An improved liquid hydrocarbon feed method is disclosed wherein substantially all of the liquid is converted to mist sized particles over a wide angled dispersion pattern without a concurrent shroud of steam or water. Such dispersion promotes vapor phase catalytic reaction between hydrocarbon vapors and fluidized catalyst in a reaction time of 1 to 3 seconds. The misting nozzle is characterized by a swirl chamber to which the full hydrocarbon feed, with or without steam included in the feed, is supplied for centrifugal rotation by vane members to form a free vortex. The flow is then released through a reduced area square-edge orifice having a short throat to form and maintain a characteristic "vena contrata" from such an orifice during flow into the catalyst stream in the riser reactor for dispersion over a wide angled conical dispersion pattern. Such flow from the orifice allows the nozzle to be recessed out of the flowing catalyst stream.

Abstract: The amount of NO.sub.x formed during regeneration of a cracking catalyst in the presence of a metallic carbon monoxide combustion catalyst is decreased without substantially adversely affecting the carbon monoxide combustion activity of the promoter by subjecting the combustion-promoting catalyst to steam treatment prior to employing it in the cracking catalyst regeneration operation.