Method of flushing pyrolysis reactor

Patent metadata

Field	Value
Publication number	US-9963641-B2
Application number	US-201214116366-A
Country	US
Kind code	B2
Filing date	Apr 9, 2012
Priority date	May 26, 2011
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

The present techniques provide a pyrolysis process that is reduced in coke and/or tar formation relative to comparable processes. A flushing fluid is applied or injected directly into a pyrolysis reactor to reduce high levels of coke and tar that can accumulate within the pyrolysis reactor during pyrolysis of the feed.

First claim

The invention claimed is:

1. A pyrolysis process, comprising:
heating a stream in a preheat zone of a regenerative pyrolysis reactor operating in a first flow direction, the regenerative pyrolysis reactor further comprising a pyrolysis reaction zone, a quenching zone, and at least one injection component, wherein the (i) the pyrolysis reaction zone is located downstream of the preheat zone, (ii) the quenching zone is located downstream of the pyrolysis reaction zone, (iii) the injection component is located downstream of the pyrolysis reaction zone, and (iv) upstream and downstream are indicated with respect to the first flow direction;
pyrolysing the stream in the pyrolysis reaction zone to produce a pyrolysis product, the product being quenched in the quenching zone;
injecting a hydrocarbon flushing fluid through the injection component into the regenerative pyrolysis reactor to mix with the product, wherein the flushing fluid comprises hydrocarbon; and
removing the product from the pyrolysis reactor.

2. The process of claim 1 , wherein the flushing fluid is comprised of a polar fluid.

3. The process of claim 1 , wherein the flushing fluid is comprised of steam or a polar aprotic fluid.

4. The process of claim 1 , wherein the injection component is located in the quenching zone upstream of the removal of the product from the pyrolysis reactor.

5. The process of claim 1 , wherein the injection of the flushing fluid is performed at a location within the regenerative pyrolysis reactor exposed to gas temperatures ≤900° C.

6. The process of claim 1 , wherein the injection of the flushing fluid is performed at a location within the regenerative pyrolysis reactor exposed to gas temperatures ≤600° C.

7. The process of claim 1 , further comprising switching the regenerative pyrolysis reactor from the pyrolysis step to a heating step, and transferring heat to the heat transfer zone and producing a second product which comprises carbon dioxide, wherein the heating step is carried out in a second flow direction that is substantially the reverse of the first flow direction.

8. The process of claim 1 , comprising:
separating the flushing fluid from the product downstream of the regenerative pyrolysis reactor;
and recycling the separated flushing fluid to the reactor.

9. The process of claim 1 , wherein the stream is comprised of a hydrocarbon having a nominal end boiling point of at least 400° F. (204° C.).

10. The process of claim 1 , wherein the flushing fluid is injected into the regenerative pyrolysis reactor at a weight ratio of flushing fluid to the produced product exiting the reaction zone of at least 0.01:1.

Assignees

• Keusenkothen Paul F
• Exxonmobil Chemical Patents Inc

Inventors

• Keusenkothen Paul F

Classifications

• B01J2219/00247

  Fouling of the reactor or the process equipment · CPC title

• B01J8/0492 Primary

  Feeding reactive fluids (for solid material, see B01J8/0015) · CPC title

• B01J2208/0053

  Controlling multiple zones along the direction of flow, e.g. pre-heating and after-cooling · CPC title

• B01J2219/00159

  controlling multiple zones along the direction of flow, e.g. pre-heating and after-cooling · CPC title

• C10G2300/708

  Coking aspect, coke content and composition of deposits · CPC title