US 12,065,401 B1
Integrated processes and systems for producing para-xylenes
Qi Xu, Dhahran (SA); Veera Venkata Ramakrishna Tammana, Dhahran (SA); and Mohammed I. Alamer, Dhahran (SA)
Assigned to Saudi Arabian Oil Company, Dhahran (SA)
Filed by Saudi Arabian Oil Company, Dhahran (SA)
Filed on Mar. 14, 2023, as Appl. No. 18/183,294.
Int. Cl. C07C 5/27 (2006.01); B01J 29/18 (2006.01); B01J 29/40 (2006.01); C07C 2/66 (2006.01); C07C 4/18 (2006.01); C07C 6/12 (2006.01); C07C 7/00 (2006.01); C07C 7/11 (2006.01)
CPC C07C 5/2737 (2013.01) [B01J 29/18 (2013.01); B01J 29/40 (2013.01); C07C 2/66 (2013.01); C07C 4/18 (2013.01); C07C 6/126 (2013.01); C07C 7/005 (2013.01); C07C 7/11 (2013.01); C07C 2523/28 (2013.01); C07C 2523/30 (2013.01); C07C 2523/42 (2013.01); C07C 2523/44 (2013.01); C07C 2523/72 (2013.01); C07C 2523/75 (2013.01); C07C 2523/755 (2013.01); C07C 2529/18 (2013.01); C07C 2529/40 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An integrated process for producing para-xylenes, the process comprising:
catalytically reforming a naphtha feed stream to form a reformate stream;
separating the reformate stream into a C1-C7 hydrocarbon stream and a C8+ hydrocarbon stream;
exposing the C1-C7 hydrocarbon stream to a first solvent in a solvent extraction unit to form a non-aromatic hydrocarbon stream and an aromatics stream;
separating the aromatics stream into a benzene stream and a toluene stream;
methylating the benzene stream in the presence of a methylation catalyst to form additional toluene stream;
combining the toluene stream and the additional toluene stream to form a toluene-rich transalkylation feed stream;
separating the C8+ hydrocarbon stream into a C9+ hydrocarbon stream and a xylene stream comprising ortho-xylene, meta-xylene, and para-xylene;
separating the xylene stream into a para-xylene stream and a xylene isomer stream comprising ortho-xylene and meta-xylene;
isomerizing the xylene isomer stream with a isomerization catalyst to produce a para-xylene rich stream;
dealkylating the C9+ hydrocarbon stream in an dealkylation unit with a dealkylation catalyst, thereby forming a dealkylated product stream;
separating the dealkylation product stream into an additional aromatics stream, an additional xylene stream, and a tri-methyl benzene rich stream; and
upgrading the toluene-rich transalkylation feed stream and the tri-methyl benzene rich stream in a transalkylation unit with a hydrogen stream and a transalkylation catalyst to produce an alkyl-benzene stream and additional amounts of non-aromatic hydrocarbon stream, aromatics stream, and xylene stream, and wherein:
a ratio by weight of the toluene-rich transalkylation feed stream to the tri-methylbenzene rich stream is from 0.3 to 3.