Methods for producing aromatics and olefins

1. A method for producing aromatics from a coker naphtha stream, the method comprising:

(a) hydrogenating the coker naphtha stream containing coker naphtha to a certain degree, wherein the coker naphtha has a boiling point of from about 25° C. to 85° C. in the presence of a first catalyst to remove diolefins and sulfur to obtain a hydrogenated stream; and

(b) subjecting the hydrogenated stream to dehydrocycloligomerization in the presence of a second catalyst to produce an aromatic-rich stream comprising benzene, toluene, and xylene, wherein the coker naphtha stream further comprises from about 0.5 wt % to about 5 wt % aromatics, and wherein the second catalyst has a metal oxide loading of about 0.2 wt % to about 1.5 wt % and is selected from the group consisting of Ga/Pt/Ge/ZSM-5, Pt/Ge/ZSM-5 and Ni—W/Ga/ZSM-5, or the second catalyst is Ga/Nd/ZSM-5.

2. The method of claim 1 , wherein the second catalyst comprises from about 0.025-0.2 wt. % of a promoter metal selected from the group consisting of Ga, Ge, Nd and/or W.

3. The method of claim 1 , wherein the aromatic-rich stream comprises at least about 40% by weight of aromatic compounds.

4. The method of claim 1 , further comprising hydrodealkylating the aromatic-rich stream in the presence of a third catalyst and hydrogen to produce a benzene-rich stream.

5. The method of claim 1 , further comprising mild hydrocracking the aromatic-rich stream in the presence of a third catalyst and hydrogen to produce a benzene-rich stream, wherein the mild hydrocracking is conducted at a temperature from about 400 to about 550° C.

6. The method of claim 5 , wherein the mild hydrocracking is conducted at a pressure of 5 bar to about 20 bar.

7. The method of claim 6 , further comprising mild hydrocracking the benzene-rich stream to produce a stream comprising greater than or equal to about 99% benzene by weight.

8. The method of claim 1 , wherein the second catalyst is selected from the group consisting of Ga/Nd/ZSM-5 and Ni—W/Ga/ZSM-5.

9. A method for producing aromatics from a coker naphtha stream containing coker naphtha, the method comprising:

(a) removing silica and particulates from the coker naphtha stream to obtain a pretreated coker naphtha stream;

(b) hydrogenating the pretreated coker naphtha stream in the presence of a first catalyst to remove diolefins and sulfur to obtain a hydrogenated stream comprising olefins; and

(c) subjecting the hydrogenated stream to an aromatization process in the presence of a second catalyst to produce an aromatic-rich stream comprising at least about 40% by weight of aromatic compounds;

wherein the coker naphtha has a boiling point of from about 25° C. to 85° C. and comprises silica and particulates;

wherein the second catalyst has a metal oxide loading of about 0.2 wt % to about 1.5 wt % and is selected from the group consisting of Ga/Pt/Ge/ZSM-5, Pt/Ge/ZSM-5 and Ni—W/Ga/ZSM-5, or the second catalyst is Ga/Nd/ZSM-5; and

wherein the coker naphtha stream comprises from about 0.5 wt % to about 5 wt % aromatics.

10. The method of claim 9 , further comprising:

(d) hydrodealkylating the aromatic-rich stream in the presence of a third catalyst to produce a benzene-rich stream; and

(e) distilling the benzene-rich stream to obtain a purified product stream comprising greater than or equal to about 99% benzene.

11. A method for producing olefins from a coker naphtha stream containing diolefins and sulfur, the method comprising:

(a) hydrogenating the coker naphtha stream, wherein the coker naphtha stream contains coker naphtha, wherein the coker naphtha has a boiling point of from about 25° C. to 85° C. in the presence of a first catalyst to remove the diolefins and the sulfur to obtain a hydrogenated stream; and

(b) subjecting the hydrogenated stream to catalytic cracking in the presence of a second catalyst at a pressure from about 50 to about 300 kPa to produce an olefin-rich stream comprising ethylene, propylene and aromatics, wherein the second catalyst has a metal oxide loading of about 2 wt % to about 10 wt % and is selected from the group consisting of Ga/Pt/Ge/ZSM-5, Pt/Ga/ZSM-5, Pt/Ge/ZSM-5 and Ni—W/Ga/ZSM-5, or the second catalyst is Ga/Nd/ZSM-5;

wherein the method further comprises removing silica and particulates from the coker naphtha stream prior to hydrogenation; and

wherein the coker naphtha stream comprises from about 0.5 wt % to about 5 wt % aromatics.

12. The method of claim 11 , wherein the second catalyst is selected from the group consisting of Ga/Nd/ZSM-5 and Ni—W/Ga/ZSM-5.

13. The method of claim 11 , wherein the olefins-rich stream comprises greater than about 55% of olefins.

14. The method of claim 9 , further comprising the steps of:

(d) hydrodealkylating the aromatic-rich stream in the presence of a third catalyst to produce a benzene-rich stream; and

(e) distilling the benzene-rich stream to obtain a purified product stream comprising greater than or equal to about 99% benzene.

15. The method of claim 1 , further comprising extracting benzene from the aromatic rich stream to obtain a benzene rich stream.

16. The method of claim 1 , wherein the coker naphtha stream further comprises from about 20 wt % to about 70 wt % paraffins, from about 20 wt % to about 45 wt % olefins, from about 0.01 wt % to about 3 wt % diolefins and from about 5 wt % to about 15 wt % naphthenes.