NOx Control in cracking catalyst regeneration

Claim 1

A process for cracking hydrocarbons in the absence of externally supplied molecular hydrogen comprising: (1) contacting steam with a carbon monoxide combustion promoter comprising a combustion-promoting metal or compound of a metal selected from platinum, palladium, iridium, osmium, ruthenium, rhodium, rhenium and copper associated with at least one particulate porous inorganic solid at a temperature of 760° C. to 1100° C. and a steam pressure of 1 atmosphere to 15 atmospheres for a period of from 2 hours to 100 hours; (2) cycling particulate cracking catalyst between a cracking zone and a catalyst regeneration zone, in a catalytic cracking system; (3) cracking said hydrocarbons in contact with said catalyst at cracking conditions in said cracking zone whereby coke is formed on said catalyst; and (4) burning coke off said catalyst with an oxygen-containing and nitrogen-containing gas at regeneration conditions in said regeneration zone in the presence of said combustion promoter.

Claim 5

A method for restricting the formation of nitrogen oxides in a hydrocarbon cracking catalyst regeneration zone wherein carbon monoxide is combusted with a molecular oxygen-containing and molecular nitrogen-containing gas in contact with a carbon monoxide combustion promoter including a combustion-promoting metal or compound metal selected from platinum, palladium, iridium, osmium, ruthenium, rhodium, rhenium and copper associated with at least one particulate porous inorganic solid, comprising: contacting said combustion promoter with steam at a temperature of 760° C. to 1100° C. and a steam pressure of 1 atmosphere to 15 atmospheres for a period of from 2 hours to 100 hours.

Claim 6

A method for restricting the formation of nitrogen oxides in a hydrocarbon cracking catalyst regeneration zone wherein carbon monoxide is combusted with a molecular oxygen-containing and molecular nitrogen-containing gas in contact with a carbon monoxide combustion promoter including a combustion-promoting metal or compound metal selected from platinum, palladium, iridium, osmium, ruthenium, rhodium, rhenium and copper associated with at least one particulate porous inorganic solid, comprising: contacting said combustion promoter with steam at a temperature of 760° C. to 1100° C. and a steam pressure of 1 atmosphere to 15 atmospheres for a period of from 2 hours to 100 hours.