Process for selectively producing light olefins in a fluid catalytic cracking process
AssigneeExxon Research & Engineering Co.
InventorsPaul K. Ladwig, John Ernest Asplin, Gordon F. Stuntz, William A. Wachter, Brian Erik Henry
Life of this patent
Estimating the term…
Abstract
A process for selectively producing C.sub.2 -C.sub.4 olefins from a catalytically cracked or thermally cracked naphtha stream. The naphtha stream is contacted with a catalyst containing from about 10 to 50 wt. % of a crystalline zeolite having an average pore diameter less than about 0.7 nanometers at reaction conditions which include temperatures from about 500 to 650.degree. C. and a hydrocarbon partial pressure from about 10 to 40 psia.
Claims16
A process for the selective production of C.sub.2 to C.sub.4 olefins which comprises feeding a catalytically or thermally cracked naphtha feedstock containing about 10 to 30 wt. % paraffins and from about 15 to 70 wt. % olefins and steam into a reaction zone and reacting the naphtha with a catalyst containing 10 to 50 wt. % of a crystalline zeolite having an average pore diameter less than about 0.7 nm at conditions including a temperature from about 500.degree. to 650.degree. C., a hydrocarbon partial pressure of 10 to 40 psia, a hydrocarbon residence time of 1 to 10 seconds, and a catalyst to feed ratio of about 2 to 10, wherein no more than about 20 wt. % of paraffins are converted to olefins wherein propylene comprises at least about 90 mol. % of the total C.sub.3 products.
A process for selectively producing C.sub.2 to C.sub.4 olefins in a process unit comprised of a reaction zone, a stripping zone, and a catalyst regeneration zone, wherein naphtha stream containing about 10 to 30 wt. % paraffins and from about 15 to 70 wt. % olefins is contacted in the reaction zone which contains a bed of catalyst, preferably in the fluidized state, which catalyst is comprised of a crystalline zeolite having an average pore diameter of less than about 0.7 nm and wherein the reaction zone is operated at a temperature from about 500.degree. to 650.degree. C., a hydrocarbon partial pressure of 10 to 40 psia, a hydrocarbon residence time of 1 to 10 seconds, and a catalyst to feed ratio, by weight, of about 4 to 10, wherein no more than about 20 wt. % of paraffins are converted to olefins, wherein propylene comprises at least about 90 mol. % of the total C.sub.3 products.
A process for selectively producing C.sub.2 to C.sub.4 olefins in a process unit comprised of a reaction zone, a stripping zone, and a catalyst regeneration zone, wherein naphtha stream containing about 10 to 30 wt. % paraffins and from about 15 to 70 wt. % olefins is contacted in the reaction zone which contains a bed of catalyst, preferably in the fluidized state, which catalyst is comprised of a crystalline zeolite having an average pore diameter of less than about 0.7 nm and wherein the reaction zone is operated at a temperature from about 500.degree. to 650.degree. C., a hydrocarbon partial pressure of 10 to 40 psia, a hydrocarbon residence time of 1 to 10 seconds, and a catalyst to feed ratio, by weight, of about 4 to 10, wherein no more than about 20 wt. % of paraffins are converted to olefins.
Dependencies are inferred from the claim text.