Supersonic treatment of vapor streams for separation and drying of hydrocarbon gases

Patent metadata

Field	Value
Publication number	US-12151188-B2
Application number	US-202217592276-A
Country	US
Kind code	B2
Filing date	Feb 3, 2022
Priority date	Dec 22, 2015
Publication date	Nov 26, 2024
Grant date	Nov 26, 2024

Abstract

Selective recovery of C2 to C4 hydrocarbons is achieved through the use of a converging-diverging nozzle, or de Laval nozzle. The vapor stream comprising C2 to C4 hydrocarbons is fed into an inlet of a de Laval nozzle having a throat. The vapor stream may have an initial temperature of between 0° C. and 100° C., and an initial pressure of between 200 psig and 500 psig. In the de Laval nozzle, the vapor stream expands after passing through the throat of the de Laval nozzle, producing a vapor stream having reduced temperature and pressure. Then, C2 to C4 hydrocarbons condense from the reduced-temperature vapor stream as liquid droplets, which may be recovered. Fractionation of C2 to C4 hydrocarbons by means of a de Laval nozzle is possible; the technique allows selective recovery of propane from a mixture of propane and ethane.

First claim

What is claimed is:

1. A method of recovering C2 to C4 hydrocarbons in a waste gas stream from a chemical reactor,
said method comprising:
passing said waste gas stream comprising said C2 to C4 hydrocarbons into an inlet of a de Laval nozzle having a throat, said waste gas stream having an initial temperature of between 0° C. and 100° C. and an initial pressure of between 200 psig and 500 psig;
expanding the waste gas stream after the vapor stream passes through the throat of the de Laval nozzle, producing a reduced-temperature stream;
condensing C2 to C4 hydrocarbons from the reduced-temperature stream as a liquid;
recovering the condensing liquid C2 to C4 hydrocarbons from said reduced-temperature stream; and
feeding at least a first portion of said recovered C2 to C4 hydrocarbons to said chemical reactor as a reactant.

2. The method of claim 1 , wherein the C2 to C4 hydrocarbons are alkanes, alkenes, or a mixture thereof.

3. The method of claim 1 , wherein the C2 to C4 hydrocarbons comprise saturated hydrocarbons.

4. The method of claim 1 , wherein the C2 to C4 hydrocarbons comprise unsaturated hydrocarbons.

5. The method of claim 1 , wherein the chemical reactor is a hydroformylation reactor, and the C2 to C4 hydrocarbons comprise C2 to C4 unsaturated hydrocarbons.

6. The method of claim 1 , wherein said waste gas stream has an initial temperature of between 0° C. and 60° C. and an initial pressure of between 275 psig and 325 psig.

7. A method of recovering C2 to C4 hydrocarbons in a waste gas stream from a chemical reactor,
said method comprising:
passing said waste gas stream comprising said C2 to C4 hydrocarbons into an inlet of a de Laval nozzle having a throat, said waste gas stream having an initial temperature of between 0° C. and 100° C. and an initial pressure of between 200 psig and 500 psig;
expanding the waste gas stream after the vapor stream passes through the throat of the de Laval nozzle, producing a reduced-temperature stream;
condensing C2 to C4 hydrocarbons from the reduced-temperature stream as a liquid; and
recovering the condensing liquid C2 to C4 hydrocarbons from said reduced-temperature stream;
wherein the waste gas stream comprises said C2 to C4 hydrocarbons and C3 to C5 oxygenated compounds;
said method further comprising a step of condensing said oxygenated compounds from said waste gas stream prior to said step of passing the waste gas stream into the inlet of the de Laval nozzle.

8. A method of recovering C2 to C4 hydrocarbons in a waste gas stream from a chemical reactor,
said method comprising:
passing said waste gas stream comprising said C2 to C4 hydrocarbons into an inlet of a de Laval nozzle having a throat, said waste gas stream having an initial temperature of between 0° C. and 100° C. and an initial pressure of between 200 psig and 500 psig;
expanding the waste gas stream after the vapor stream passes through the throat of the de Laval nozzle, producing a reduced-temperature stream;
condensing C2 to C4 hydrocarbons from the reduced-temperature stream as a liquid; and
recovering the condensing liquid C2 to C4 hydrocarbons from said reduced-temperature stream;
wherein the chemical reactor is a gas phase polymerization reactor, and the C2 to C4 hydrocarbons comprise unsaturated C2 to C4 hydrocarbons; and
wherein the waste gas stream comprises said unsaturated C2 to C4 hydrocarbons and hydrocarbons having a boiling point of between 5° C. and 100° C.;
said method further comprising a step of condensing said hydrocarbons having a boiling point of between 5° C. and 100° C. from said waste gas stream prior to said step of passing the waste gas stream into the inlet of the de Laval nozzle.

9. A method of recovering C2 to C4 hydrocarbons in a waste gas stream from a chemical reactor, said method comprising:
passing said waste gas stream comprising said C2 to C4 hydrocarbons into an inlet of a de Laval nozzle having a throat, said waste gas stream having an initial temperature of between 0° C. and 100° C. and an initial pressure of between 200 psig and 500 psig;
expanding the waste gas stream after the vapor stream passes through the throat of the de Laval nozzle, producing a reduced-temperature stream;
condensing C2 to C4 hydrocarbons from the reduced-temperature stream as a liquid:
recovering the condensing liquid C2 to C4 hydrocarbons from said reduced-temperature stream;
fractionating said recovered C2 to C4 hydrocarbons to produce a first fraction of C3 hydrocarbons; and
feeding at least a first portion of said first fraction to said chemical reactor as a reactant.

10. The method of claim 9 , wherein fractionating comprises selective adsorption of propene onto a zeolite molecular sieve, or distillation.

11. A method of recovering C2 to C4 hydrocarbons in a waste gas stream from a chemical reactor,
said method comprising:
passing said waste gas stream comprising said C2 to C4 hydrocarbons into an inlet of a de Laval nozzle having a throat, said waste gas stream having an initial temperature of between 0° C. and 100° C. and an initial pressure of between 200 psig and 500 psig;
expanding the waste gas stream after the vapor stream passes through the throat of the de Laval nozzle, producing a reduced-temperature stream;
condensing C2 to C4 hydrocarbons from the reduced-temperature stream as a liquid; and
recovering the condensing liquid C2 to C4 hydrocarbons from said reduced-temperature stream;
wherein said recovered C2 to C4 hydrocarbons comprise 85% to 100% C3 hydrocarbons, said method further comprising:
fractionating said C3 hydrocarbons into a propane-rich fraction and a propene-rich fraction; and
feeding at least a portion of said propene-rich fraction to said chemical reactor as a reactant.

12. A method of recycling C3 hydrocarbons in a waste gas stream from a chemical reactor,
said method comprising:
passing said waste gas stream comprising said C3 hydrocarbons into an inlet of a de Laval nozzle having a throat, said waste gas stream having an initial temperature of between 0° C. and 100° C. and an initial pressure of between 200 psig and 500 psig;
expanding the waste gas stream after the vapor stream passes through the throat of the de Laval nozzle, producing a reduced-temperature stream;
condensing a first portion of said C3 hydrocarbons from the reduced-temperature stream as a liquid;
allowing non-condensed gases to exit the de Laval nozzle;
recovering the first portion from said reduced-temperature stream; and feeding at least a part of said first portion to said chemical reactor as a
reactant.

13. The method of claim 12 , wherein the chemical reactor is a hydroformylation reactor.

14. The method of claim 12 , wherein the chemical reactor is a gas phase polymerization reactor.

15. The method of claim 12 , wherein the non-condensed gases comprise non-condensed C3 hydrocarbons;
said method further comprising:
passing said non-condensed gases into an inlet of a second de Laval nozzle having a throat, said non-condensed gases having an initial temperature of between 0° C. and 100° C. and an initial pressure of between 250 psig and 400 psig;
expanding the non-condensed gases in the second de Laval nozzle;
condensing a second portion of said C3 hydrocarbons from the expanded non-condensed gases as a liquid;
recovering the second portion of said liquid C3 hydrocarbons.

16. The method of claim 15 , said method further comprising:
recovering the expanded non-condensed gases from the outlet of the second de Laval nozzle; and
performing at least one step of condensing further C3 hydrocarbons fr

Assignees

• Eastman Chem Co
• Univ North Carolina State

Inventors

• Shaikh Ashfaq Shahanawaz
• Puckette Thomas Allen
• Owens Scott Allen
• Maaz Syed Mohammed
• Edwards Jack R

Classifications

• C10G2400/20

  C2-C4 olefins · CPC title

• C10G50/00

  Production of liquid hydrocarbon mixtures from lower carbon number hydrocarbons, e.g. by oligomerisation · CPC title

• C07C45/28

  of CHx-moieties · CPC title

• B01D2257/7022

  Aliphatic hydrocarbons · CPC title

• B01D3/16

  Fractionating columns in which vapour bubbles through liquid (packing elements B01J19/30, B01J19/32) · CPC title