FCC process

A catalytic cracking process comprising:

• (a) passing a first portion of regenerated catalyst to a FCC reactor configured to have a plurality of zones;
• (b) in a first upstream zone, contacting the first portion of regenerated catalyst with a secondary FCC feed, the secondary feed comprising between 2 and 50 wt % steam based on the total weight of the secondary feed and light cat naphtha wherein the residence time of the secondary feed in the first upstream zone is less than about 1.5 seconds and wherein the catalyst to secondary feed weight ratio is between about 30:1 and about 150:1;
• (c) in a first primary feed conversion zone downstream from the first upstream zone, contacting the effluent from the first upstream zone with a primary FCC feed, wherein the effluent of the first upstream zone has sufficient enthalpy to vaporize at least 50 wt % of the FCC primary feed, the primary FCC feed comprising hydrocarbons boiling in the range of between about 250° C. and about 575° C., wherein the residence time within the first primary feed conversion zone is between about 0.2 and about 0.5 seconds and the catalyst to oil weight ratio is between about 2:1 and about 5:1;
• (d) contacting a second portion of regenerated catalyst with a secondary FCC feed, the second portion of regenerated catalyst comprising a catalytic cracking catalyst, the secondary feed comprising steam and hydrocarbons boiling in the range of about 25° C. to about 250° C. and then passing the second portion of regenerated catalyst and partially converted secondary FCC feed to a second primary feed conversion zone positioned downstream from the first primary feed conversion zone;
• and,
• (e) in the second primary feed conversion zone, contacting the effluent of the first primary feed conversion zone with the second portion of regenerated catalyst wherein the residence time within the second primary feed conversion zone is less than about 2 seconds, wherein the ratio of the first portion of catalyst to the second portion of catalyst is between about 1:1 and about 1:2.

A catalytic cracking process comprising:

• (a) passing a first portion of regenerated catalyst to a FCC reactor configured to have a plurality of zones;
• (b) in a first upstream zone, contacting the first portion of regenerated catalyst with a secondary FCC feed, the secondary feed comprising steam and hydrocarbons boiling in the range of about 25° C. to about 250° C. wherein the residence time of the secondary feed in the first upstream zone is less than about 1.5 seconds;
• (c) in a first primary feed conversion zone downstream from the first upstream zone, contacting the effluent from the first upstream zone with a primary FCC feed, wherein the effluent of the first upstream zone has sufficient enthalpy to vaporize at least 50 wt % of the FCC primary feed, the primary FCC feed comprising hydrocarbons boiling in the range of between about 250° C. and about 575° C., wherein the residence time within the first conversion zone is between about 0.2 and about 2 seconds and the catalyst to oil weight ratio is between about 2:1 and about 5:1;
• (d) in a second primary feed conversion zone downstream from the first primary feed conversion zone, contacting the effluent of the first primary feed conversion zone with a second portion of regenerated catalyst passed into the second conversion zone, the regenerated catalyst passed into the second conversion zone comprising a catalytic cracking catalyst wherein the residence time within the second primary feed conversion zone is less than about 10 seconds;
• and
• (e) in a third primary feed conversion zone downstream from the second primary feed conversion zone, contacting the effluent of the second primary feed conversion zone with a third portion of regenerated catalyst passed into the third conversion zone, the regenerated catalyst comprising a catalytic cracking catalyst, wherein the residence time in the third primary feed conversion zone is between about 0.2 and 1 second.

A catalytic cracking process comprising:

• (a) passing a first portion of regenerated catalyst to a FCC reactor configured to have a plurality of zones;
• (b) in a first upstream zone, contacting the first portion of regenerated catalyst with a secondary FCC feed, the secondary feed comprising between about 2 and about 50 wt % steam based on the total weight of the secondary feed and light cat naphtha wherein the residence time of the secondary feed in the first upstream zone is less than about 1.5 seconds and wherein the catalyst to secondary feed weight ratio is between about 30:1 and about 150:1;
• (c) in a first primary feed conversion zone downstream from the first upstream zone, contacting the effluent from the first upstream zone with a primary FCC feed, wherein the effluent of the first upstream zone has sufficient enthalpy to vaporize at least 50 wt % of the FCC primary feed, the primary FCC feed comprising hydrocarbons boiling in the range of between about 250° C. and about 575° C., wherein the residence time within the first conversion zone is between about 0.2 and about 2 seconds and the catalyst to oil weight ratio is between about 2:1 and about 5:1;
• (d) in a second primary feed conversion zone downstream from the first primary feed conversion zone, contacting the effluent of the first primary feed conversion zone with a second portion of regenerated catalyst passed into the second conversion zone, the regenerated catalyst passed into the second conversion zone comprising a catalytic cracking catalyst wherein the residence time within the second primary feed conversion zone is less than about 10 seconds;
• and
• (e) in a third primary feed conversion zone downstream from the second primary feed conversion zone, contacting the effluent of the second primary feed conversion zone with a third portion of regenerated catalyst passed into the third conversion zone, the regenerated catalyst comprising a catalytic cracking catalyst, wherein the residence time in the third primary feed conversion zone is between about 0.2 and 1 second
• wherein the weight ratio of the first portion of catalyst to the sum of the weights of the second and third portions of catalyst is between about 1:1 and about 1:2, and wherein the weight ratio of the second portion of catalyst to the third portion of catalyst is between about 1:2 and about 1:1.