Method for characterizing the hydrocarbon content of a reformate stream

Patent metadata

Field	Value
Publication number	US-9933408-B2
Application number	US-201414536949-A
Country	US
Kind code	B2
Filing date	Nov 10, 2014
Priority date	Nov 10, 2014
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

Method for characterizing the hydrocarbon content of a reformate sample stream comprising methane, water, carbon monoxide, ammonia, and hydrogen from a steam-hydrocarbon reforming process. Water and ammonia are removed from the reformate sample stream and the hydrocarbon content of the reformate sample stream depleted in water and ammonia is measured using a chemical component analyzer.

First claim

I claim:

1. A method for characterizing a hydrocarbon content of a reformate sample stream, the method comprising:
(a) withdrawing the reformate sample stream from a steam-hydrocarbon reforming process, the reformate sample stream comprising CH 4 , H 2 O, CO, NH 3 , and H 2 ;
(b) cooling the reformate sample stream in a first heat exchanger to condense a portion of the H 2 O in the reformate sample stream thereby forming a liquid fraction and a vapor fraction;
(c) dividing the reformate sample stream from step (b) into a vapor fraction-enriched stream having a time-averaged mass flow rate, F 1 , and a liquid fraction-enriched stream having a time-averaged mass flow rate, F 2 ;
(d) cooling the vapor fraction-enriched stream to within a temperature ranging from 0° C. to 10° C. to condense H 2 O in the vapor fraction-enriched stream;
(e) removing at least a portion of the condensed H 2 O from the vapor fraction-enriched stream from step (d);
(f) passing the vapor fraction-enriched stream from step (e) to an ammonia removal unit to remove NH 3 from the vapor fraction-enriched stream; and
(g) passing at least a first portion of the vapor fraction-enriched stream from step (f) to a chemical component analyzer to measure the hydrocarbon content in the at least a first portion of the vapor fraction-enriched stream.

2. The method of claim 1 wherein the vapor fraction-enriched stream from step (f) is passed to a dryer to further remove H 2 O in the vapor fraction-enriched stream prior to passing the at least a first portion of the vapor fraction-enriched stream to the chemical component analyzer.

3. The method of claim 1 wherein F 1 and F 2 are controlled such that

F
1

F
1

+

F
2

≤

0.2
.

4. The method of claim 1 wherein the vapor fraction-enriched stream is cooled in step (d) to within a temperature ranging from 2° C. to 7° C.

5. The method of claim 1 further comprising passing the reformate sample stream through a conduit from a reformate sample stream source to the first heat exchanger while heating the reformate sample stream in the conduit in an amount sufficient to prevent condensation of the H 2 O in the reformate sample stream in the conduit.

6. The method of claim 1 wherein the at least a portion of the condensed H 2 O from the vapor fraction-enriched stream is removed using a liquid drain trap.

7. The method of claim 1 wherein the at least a portion of the condensed H 2 O from the vapor fraction-enriched stream is removed using a liquid drain trap and a coalescing filter.

8. The method of claim 1 wherein the ammonia removal unit comprises phosphoric acid.

9. The method of claim 1 further comprising: rejecting a second portion of the vapor fraction-enriched stream from step (f) where the second portion is not passed to the chemical component analyzer, wherein the at least a first portion of the vapor fraction-enriched stream has a time-averaged mass flow rate V 1 , the second portion of the vapor fraction-enriched stream has a time-averaged mass flow rate, V 2 , where

V
1

V
1

+

V
2

≤

0.1
.

10. The method of claim 1 wherein the vapor fraction-enriched stream is cooled in step (d) in a second heat exchanger wherein the second heat exchanger comprises a vortex tube wherein compressed air is introduced into the vortex tube to provide the cooling of the vapor fraction-enriched stream.

11. The method of claim 2 wherein the dryer is a membrane dryer.

12. The method of claim 11 wherein dry N 2 or dry air is introduced into the membrane dryer as a purge gas to assist in the removal of H 2 O from the vapor fraction-enriched stream.

13. The method of claim 1 wherein the reformate sample stream has an H 2 O mole fraction greater than 0.35.

14. The method of claim 1 wherein the chemical component analyzer is a gas chromatograph.

Assignees

• Air Prod & Chem

Inventors

• Macconnell Matthew H

Classifications

• G01N9/32

  by using flow properties of fluids, e.g. flow through tubes or apertures · CPC title

• Y10T436/21

  Hydrocarbon · CPC title

• G01N2030/8854

  involving hydrocarbons · CPC title

• B01D2257/406

  Ammonia · CPC title

• G01N33/2835 Primary

  Specific substances contained in the oils or fuels · CPC title