Highly selective olefin removal with unsulfided hydrotreating catalysts

Patent metadata

Field	Value
Publication number	US-10562829-B1
Application number	US-201816212186-A
Country	US
Kind code	B1
Filing date	Dec 6, 2018
Priority date	Dec 6, 2018
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

A process is disclosed for polishing a relatively highly pure stream of aromatic material bound for use as a petrochemical feedstock wherein the stream includes olefins and especially concerning, diolefins. The process comprises hydrotreating the highly pure aromatic stream with an unsulfided cobalt molybdenum catalyst that has low saturating activity for the aromatic but is active for saturating olefins and diolefins.

First claim

The invention claimed is:

1. A process for producing a high purity aromatic product such as benzene, toluene, xylene where concerns arise for olefin and diolefin content, where the process comprises:
forming an aromatic stream comprising at least 99% by weight the aromatic product desired where the stream includes measurable diolefin content;
delivering the stream to a hydrotreater having a catalyst comprising cobalt and molybdenum and has not been treated with a sulfiding agent prior to this step of delivering the stream to the hydrotreater, wherein the temperature of the stream is between 400° F. and 600° F.; and
converting at least 90 percent of the diolefins to alkanes in the hydrotreater while, at the same time, converting less than 10 ppm aromatic to cyclohexene such that the bromine index of the aromatic stream is reduced.

2. The process according to claim 1 wherein any sulfur in the aromatic stream is converted to hydrogen sulfide in the hydrotreater and removed from the aromatic stream downstream of the hydrotreater.

3. The process according to claim 1 wherein the pressure in the hydrotreater is between 175 psig and 275 psig.

4. The process according to claim 1 wherein the liquid hourly space velocity in the hydrotreater is between 2 and 8 hr −1 .

5. The process according to claim 1 wherein the aromatic stream includes sulfur species and where the process further includes adhering sulfur species to a sorbent to further reduce the sulfur content of the aromatic stream.

6. The process according to claim 1 wherein the measurable diolefin content is 0.001 wt % or more.

Assignees

• Phillips 66 Co

Inventors

• Choudhary Tushar
• Pham Tu N
• Uppili Sundararajan

Classifications

• C07C7/163

  by hydrogenation · CPC title

• C10G45/38

  in combination with chromium, molybdenum or tungsten metals, or compounds thereof · CPC title

• C10G2400/30

  Aromatics · CPC title

• C10G45/36

  containing nickel or cobalt metal, or compounds thereof · CPC title

• C07C5/03

  of non-aromatic carbon-to-carbon double bonds · CPC title