Upgrading hydrocarbon pyrolysis products

Patent metadata

Field	Value
Publication number	US-9637694-B2
Application number	US-201514683482-A
Country	US
Kind code	B2
Filing date	Apr 10, 2015
Priority date	Oct 29, 2014
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

The invention relates to a process for upgrading pyrolysis tar, such as steam cracker tar, in the presence of a utility fluid. The utility fluid contains 2-ring and/or 3-ring aromatics and has solubility blending number (S BN )≧120. The invention also relates to the upgraded pyrolysis tar and to the use of the upgraded pyrolysis tar, for example, for fuel oil blending.

First claim

The invention claimed is:

1. A hydrocarbon conversion process, comprising:
(a) providing a pyrolysis feedstock comprising ≧10.0 wt. % hydrocarbon based on the weight of the pyrolysis feedstock;
(b) pyrolysing the pyrolysis feedstock to produce a pyrolysis effluent comprising pyrolysis tar and ≧1.0 wt. % of C 2 unsaturates, based on the weight of the pyrolysis effluent;
(c) separating at least a portion of the pyrolysis tar from the pyrolysis effluent, wherein the separated pyrolysis tar has I N >110 and ≧90 wt. % of the pyrolysis effluent's molecules have an atmospheric boiling point of ≧290° C.;
(d) providing a utility fluid, the utility fluid comprising ring aromatics, in an amount ≧25.0 wt. % based on the weight of the utility fluid, and the utility fluid having S BN ≧120;
(e) combining at least a portion of the separated pyrolysis tar and utility fluid;
(f) providing treat gas comprising molecular hydrogen;
(g) hydroprocessing the combined pyrolysis tar and utility fluid in a hydroprocessing zone in the presence of treat gas under catalytic hydroprocessing conditions to produce hydroprocessed effluent, comprising hydroprocessed tar;
(h) separating from the hydroprocessed effluent a bottoms stream and a first vapor stream;
(i) separating from the first vapor stream a mid-cut stream and a second vapor stream;
(j) separating from the second vapor stream a light liquid overhead stream and a total vapor product;
(k) combining at least a portion of the mid-cut stream with at least a portion of the bottoms stream to form a heavy mid-cut stream, the heavy mid-cut stream having S BN ≧120; and
(l) conducting at least a portion of the heavy mid-cut stream to step (d), wherein the utility fluid comprises ≧10.0 wt. % of the heavy mid-cut stream, based on the weight of the utility fluid.

2. The process of claim 1 , wherein the pyrolysis tar has I N >130.

3. The process of claim 1 , wherein the utility fluid has a S BN ≧130.

4. The process of claim 1 , wherein the combined pyrolysis tar and utility fluid in step (e) has a S BN ≧140.

5. The process of claim 1 , wherein the combined pyrolysis tar and utility fluid in step (e) has a S BN ≧150.

6. The process of claim 1 , wherein the utility fluid has a true boiling point distribution having (i) an initial boiling point ≧177° C. and (ii) a final boiling point ≦566° C.

7. The process of claim 1 , wherein the utility fluid has a true boiling point distribution having (i) an initial boiling point ≧177° C. and (ii) a final boiling point ≦430° C.

8. The process of claim 1 , wherein the utility fluid comprises ≧25.0 wt % two ring and/or three ring aromatic compounds.

9. The process of claim 1 , wherein the pyrolysis feedstock hydrocarbon comprises one or more of naphtha, gas oil, vacuum gas oil, waxy residues, atmospheric residues, residue admixtures, or crude oil.

10. The process of claim 1 , wherein the pyrolysis effluent's tar comprises (i) ≧10.0 wt. % of molecules having an atmospheric boiling point ≧565° C. that are not asphaltenes, and (ii) ≦1.0×10 3 ppmw metals, the weight percents being based on the weight of the pyrolysis effluent's tar.

11. The process of claim 1 , wherein (i) the hydroprocessing in step (g) is conducted continuously in a hydroprocessing zone from a first time t 1 to a second time t 2 , t 2 being ≧(t 1 +80 days) and (ii) hydroprocessing zone's pressure drop at the second time is increased ≦10.0% over the pressure drop at the first time.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Evans Christopher M
• Soultanidis Nikolaos
• KOC-KARABOCEK Reyyan
• Ferrughelli David T
• Xu Teng

Classifications

• C10G2300/80

  Additives · CPC title

• C10G69/06 Primary

  including at least one step of thermal cracking in the absence of hydrogen · CPC title

• C10G9/36

  with heated gases or vapours · CPC title