Method and system for controlling the activity of a crystalline zeolite cracking catalyst

Claim 3

The method of claim 1 wherein the crystalline zeolite containing cracking catalyst comprises a mixture of faujasite cracking catalyst particles and ZSM-5 type catalyst particles containing an oxidation promoter for converting carbon monoxide to carbon dioxide.

Claim 4

In a hydrocarbon conversion process relying upon a catalyst comprising a crystalline zeolite wherein carbonaceous deposits deactivate the catalyst during conversion and the deactivated catalyst is then regenerated with an oxygen containing gas the improvement which comprises, heat soaking a crystalline zeolite conversion catalyst contaminated with carbonaceous deposits of hydrocarbon conversion in the presence of gas substantially inert to the environment at a temperature of at least 1000*F. for a period of time of at least 10 minutes and thereafter using the heat soaked catalyst combined with freshly regenerated catalyst for further hydrocarbon conversion before passing the catalyst to regeneration with an oxygen containing regeneration gas.

Claim 5

In a hydrocarbon conversion process relying upon a catalyst comprising a crystalline zeolite wherein carbonaceous deposits deactivate the catalyst during conversion and the deactivated catalyst is then regenerated with an oxygen containing gas the improvement which comprises, heat soaking a crystalline zeolite conversion catalyst contaminated with carbonaceous deposits of hydrocarbon conversion in the presence of gas substantially inert to the environment at a temperature of at least 1000*F. for a period of time of at least 10 minutes and thereafter using the heat soaked catalyst combined with freshly regenerated catalyst for further hydrocarbon conversion before passing the catalyst to regeneration with an oxygen containing regeneration gas.

Claim 8

In a hydrocarbon conversion operation using a crystalline zeolite containing cracking catalyst and regeneration of the catalyst with an oxygen containing regeneration gas to remove deposited carbonaceous material the improvement which comprises passing regenerated catalyst suspended in hydrocarbon material through a riser cracking zone at a temperature of at least 1000*F. for a hydrocarbon residence time less than 10 seconds, separating the product obtained in said riser cracking zone into a hydrocarbon phase and a catalyst phase, heat soaking the catalyst phase thus separated with freshly regenerated catalyst at a temperature of at least 1000*F. for at least 5 minutes in the presence of steam stripping gas, passing the heat soaked catalyst admixed with additional hot regenerated catalyst and suspended in hydrocarbon feed material through an additional hydrocarbon conversion zone maintained at a temperature of at least 1000*F. and at a hydrocarbon residence time less than 10 seconds, separating catalyst containing carbonaceous deposits from hydrocarbon vapors removed from said additional hydrocarbon conversion zone, stripping the separated catalyst, passing the stripped catalyst to a fluid bed of catalyst in the lower end of an elongated riser regeneration zone, raising the temperature of said fluid bed of catalyst with freshly regenerated catalyst and by burning deposited carbonaceous material on the catalyst particles with oxygen containing gas, passing the catalyst particles thus contacted with gaseous products of carbonaceous material combustion upwardly through elongated riser regeneration zone, adding additional oxygen containing gas to said upflowing catalyst particles to obtain combustion of formed carbon monoxide, separating hot regenerated catalyst from combustion product gases at the end of said riser regeneration zone, collecting the separated catalyst as a dense fluid bed of catalyst at a temperature in the range of 1000* to 1600*F. contacting the thus collected dense fluid bed of catalyst with oxygen containing gas and using the regenerated catalyst in the hydrocarbon conversion and catalyst regeneration combination as above recited.

Claim 9

In a hydrocarbon conversion operation using a crystalline zeolite containing cracking catalyst and regeneration of the catalyst with an oxygen containing regeneration gas to remove deposited carbonaceous material the improvement which comprises passing regenerated catalyst suspended in hydrocarbon material through a riser cracking zone at a temperature of at least 1000*F. for a hydrocarbon residence time less than 10 seconds, separating the product obtained in said riser cracking zone into a hydrocarbon phase and a catalyst phase, heat soaking the catalyst phase thus separated with freshly regenerated catalyst at a temperature of at least 1000*F. for at least 5 minutes in the presence of steam stripping gas, passing the heat soaked catalyst admixed with additional hot regenerated catalyst and suspended in hydrocarbon feed material through an additional hydrocarbon conversion zone maintained at a temperature of at least 1000*F. and at a hydrocarbon residence time less than 10 seconds, separating catalyst containing carbonaceous deposits from hydrocarbon vapors removed from said additional hydrocarbon conversion zone, stripping the separated catalyst, passing the stripped catalyst to a fluid bed of catalyst in the lower end of an elongated riser regeneration zone, raising the temperature of said fluid bed of catalyst with freshly regenerated catalyst and by burning deposited carbonaceous material on the catalyst particles with oxygen containing gas, passing the catalyst particles thus contacted with gaseous products of carbonaceous material combustion upwardly through elongated riser regeneration zone, adding additional oxygen containing gas to said upflowing catalyst particles to obtain combustion of formed carbon monoxide, separating hot regenerated catalyst from combustion product gases at the end of said riser regeneration zone, collecting the separated catalyst as a dense fluid bed of catalyst at a temperature in the range of 1000* to 1600*F. contacting the thus collected dense fluid bed of catalyst with oxygen containing gas and using the regenerated catalyst in the hydrocarbon conversion and catalyst regeneration combination as above recited.