Integrated light olefin separation/cracking process

1. A method for producing a hydrocarbon comprising:

contacting a hydrocarbon comprising olefins and paraffins with an adsorbent;

adsorbing at least a portion of the olefins to provide an olefin-lean hydrocarbon;

displacing at least a portion of the adsorbed olefins from the adsorbent with a displacement medium to provide a mixture of the displacement medium and an olefin-rich hydrocarbon comprising about 95 wt % or more olefins;

fractionating the olefin-lean hydrocarbon to provide a first recycle displacement medium and a paraffin-rich hydrocarbon comprising about 70 wt % or more paraffins;

separating the displacement medium from the olefin-rich hydrocarbon to produce a second recycle displacement medium;

cracking at least a portion of the olefin-rich hydrocarbon in the presence of one or more catalysts at a temperature of about 605° C. to about 670° C. to produce a first cracked product comprising about 95 wt % or more C 2 -C 10 hydrocarbons, wherein the C 2 -C 10 hydrocarbons comprise about 20 wt % or more C 2 -C 3 olefins;

separating the first cracked product to provide an ethylene product; and

recycling at least a portion of the ethylene product to the olefin-rich hydrocarbon prior to cracking.

2. The method of claim 1 , further comprising cracking the paraffin-rich hydrocarbon at conditions sufficient to produce a second cracked product comprising from about 10 wt % to about 60 wt % ethylene and from about 5 wt % to about 50 wt % propylene.

3. The method of claim 2 , further comprising:

mixing the first cracked product with the second cracked product prior to separating the first cracked product to provide the ethylene product.

4. The method of claim 1 , wherein adsorbing at least a portion of the olefins comprises recovering about 95 wt % or more of the olefins contained in the hydrocarbon.

5. The method of claim 1 , wherein adsorbing at least a portion of the olefins comprises multi-bed adsorption.

6. The method of claim 1 , wherein the olefin-rich hydrocarbon comprises about 99.99 wt % olefins.

7. The method of claim 1 , wherein the paraffin-rich hydrocarbon comprises about 90 wt % or more C 2 -C 12 paraffins.

8. The method of claim 1 , wherein the hydrocarbon comprises about 75 wt % or more C 2 -C 5 olefins and paraffins.

9. The method of claim 8 , wherein the olefin-rich hydrocarbon comprises about 95 wt % or more C 2 -C 5 olefins and the paraffin-rich hydrocarbon comprises about 60 wt % or more C 2 -C 5 paraffins.

10. The method of claim 1 , wherein cracking the olefin-rich hydrocarbon in the presence of one or more catalysts further comprises conditions comprising a residence time of less than 2 seconds, temperatures of about 615° C. to about 650° C., and pressures from about 650 kPa to about 725 kPa.

11. The method of claim 1 , wherein the olefin-rich hydrocarbon comprises about 98.5 wt % or more C 2 -C 4 olefins.

12. The method of claim 1 , further comprising:

separating the first cracked product to provide a methane product and a bottoms product comprising C 2 and C 3 hydrocarbons;

recycling at least a portion of the methane product to the olefin-rich hydrocarbon prior to cracking;

cracking at least a portion of the paraffin-rich hydrocarbon to provide a second cracked product; and

recycling a portion of the bottoms product to the paraffin-rich hydrocarbon prior to cracking.

13. A method for producing a hydrocarbon comprising:

separating a hydrocarbon comprising olefins and paraffins, comprising:

purifying the hydrocarbon to provide a purified hydrocarbon;

contacting the purified hydrocarbon with an adsorbent;

adsorbing at least a portion of any olefins contained in the purified hydrocarbon to provide an olefin-lean hydrocarbon;

displacing at least a portion of the adsorbed olefins with a displacement medium to provide an olefin-rich hydrocarbon mixed with the displacement medium;

fractionating the olefin-lean hydrocarbon to produce a paraffin-rich product comprising about 60 wt % or more C 2 -C 5 paraffins;

fractionating the olefin-rich hydrocarbon mixed with the displacement medium to produce an olefin-rich product comprising about 95 wt % or more olefins and a recycle displacement medium;

cracking at least a portion of the olefin-rich product in the presence of one or more catalysts at conditions comprising temperatures from about 605° C. to about 670° C. to produce a cracked product comprising about 95 wt % or more C 2 -C 10 hydrocarbons, wherein the C 2 -C 10 hydrocarbons comprise about 20 wt % or more C 2 -C 3 olefins;

separating the cracked product to provide an ethylene product; and

recycling at least a portion of the ethylene product to the olefin-rich hydrocarbon prior to cracking.

14. The method of claim 13 , wherein the olefin-rich product is cracked at a temperature of from about 615° C. to about 650° C.

15. The method of claim 13 , wherein adsorption of the olefins occurs within a multi-bed adsorption unit.

16. The method of claim 13 , wherein the olefin-rich product comprises about 99.99 wt % olefins.

17. The method of claim 13 , wherein the olefin-rich product is cracked at a pressure of about 68 kPa to about 690 kPa.

18. The method of claim 13 , wherein separating the cracked product to provide the ethylene product comprises fractionating the cracked product to produce a naphthenic mixture and an olefinic mixture, and separating the olefinic mixture to provide the ethylene product.

19. The method of claim 18 , further comprising:

compressing the olefinic mixture to produce a compressed olefinic mixture;

treating the compressed olefinic mixture to produce a treated olefinic mixture;

drying the treated olefinic mixture to produce a dried olefinic mixture;

separating the dried olefinic mixture to produce an overhead comprising C 3 and lighter hydrocarbons and a bottoms comprising C 4 and heavier hydrocarbons; and

separating the overhead comprising C 3 and lighter hydrocarbons to provide the ethylene product.

20. A method for retrofitting a fluid catalytic cracking system having a hydrocarbon comprising a mixture of olefins and paraffins introduced thereto, the method comprising:

diverting at least a portion of the hydrocarbon to be introduced to the fluid catalytic cracking system to a separation unit comprising an adsorbent prior to being introduced to the fluid catalytic cracking system;

contacting the at least a portion of the hydrocarbon with the adsorbent;

adsorbing at least a portion of the olefins to provide an olefin-lean hydrocarbon;

displacing at least a portion of the adsorbed olefins from the adsorbent with a displacement medium to provide a mixture of the displacement medium and an olefin-rich hydrocarbon comprising about 95 wt % or more olefins;

fractionating the olefin-lean hydrocarbon to provide a first recycle displacement medium and a paraffin-rich hydrocarbon comprising about 70 wt % or more paraffins;

fractionating the mixture of the olefin-rich hydrocarbon and the displacement medium to produce the olefin-rich hydrocarbon and a second recycle displacement medium;

introducing the olefin-rich hydrocarbon to a fluid catalytic cracker to crack at least a portion of the olefin-rich hydrocarbon in the presence of one or more catalysts at conditions comprising temperatures from about 605° C. to about 670° C. to produce a first cracked product comprising about 95 wt % or more C 2 -C 10 hydrocarbons, wherein the C 2 -C 10 hydrocarbons comprise about 20 wt % or more C 2 -C 3 olefins;

separating the first cracked product to provide an ethylene product; and

recycling at least a portion of the ethylene product to the olefin-rich hydrocarbon prior to cracking.

21. The method of claim 20 , wherein adsorption of the olefins occurs within a multi-bed adsorption unit.

22. The method of claim 20 , wherein the olefin-rich product comprises about 99.99 wt % olefins.