Apparatus and system for swing adsorption processes
Provided are apparatus and systems for performing a swing adsorption process. This swing adsorption process may involve performing a startup mode process prior to beginning a normal operation mode process to remove contaminants from a gaseous feed stream. The startup mode process may be utilized for swing adsorption processes, such as TSA and/or PSA, which are utilized to remove one or more contaminants from a gaseous feed stream.
1. A process for removing contaminants from a gaseous feed stream with a swing adsorption process, the process comprising:
a) performing a purge step, wherein the purge step comprises passing an external gas stream through an adsorbent bed unit to remove one or more contaminants from an adsorbent bed within a housing of the adsorbent bed unit to form a purge product stream;
b) performing one or more adsorption steps, wherein each of the one or more adsorption steps comprise passing a gaseous feed stream through an adsorbent bed unit having an adsorbent bed to separate one or more contaminants from the gaseous feed stream to form a product stream;
c) determining whether the product stream is within a specification for a contaminant;
d) if the product stream is within the specification, passing the product stream to a downstream process;
e) if the product stream is not within the specification, repeating the steps a) to d) for at least one additional cycle;
wherein the process further comprises mixing a slip stream from the downstream process with the external gas stream prior to performing the purge step.
2. The process of claim 1 , further comprising adjusting the amount of external gas stream utilized in the performing a purge step based on the amount of the slip stream from the downstream process.
3. The process of claim 1 , further comprising heating the external gas stream prior to passing the external gas stream through an adsorbent bed unit.
4. The process of claim 3 , wherein the external gas stream is heated to a temperature in the range between 500° F. and greater than 50° F. of the gaseous feed stream temperature.
5. The process of claim 3 , wherein the external gas stream is heated to a temperature in the range between 450° F. and the gaseous feed stream temperature.
6. The process of claim 1 , further comprising heating the purge product stream, wherein the purge product stream is heated to a temperature 10° F. greater than the dew point of the purge product stream.
7. The process of claim 5 , further comprising:
separating one or more contaminants from the purge product stream to form conditioned purge product stream; and
mixing the conditioned purge product stream with external gas source stream to form the external gas stream.
8. The process of claim 1 , wherein the purge stream is passed in a countercurrent direction relative to the direction of the feed stream and wherein a temperature differential exists at the end of the purge step in a range between 100° F. and 400° F., wherein the temperature differential is the difference in temperatures between a feed end of the adsorbent bed and a product end of the adsorbent bed.
9. The process of claim 1 , wherein the cycle duration is for a period greater than 1 second and less than 2400 seconds.
10. The process of claim 1 , wherein the gaseous feed stream is a hydrocarbon containing stream having greater than one volume percent hydrocarbons based on the total volume of the feed stream.
11. The process of claim 1 , wherein the gaseous feed stream comprises hydrocarbons and CO 2 , wherein the CO 2 content is in the range of two hundred parts per million volume to less than or equal to about 2% volume of the gaseous feed stream.
12. The process of claim 1 , wherein the adsorbent bed unit is configured to lower the carbon dioxide (CO 2 ) level to less than 50 parts per million.
13. The process of claim 1 , wherein the gaseous feed stream comprises hydrocarbons and H 2 O, wherein the H 2 O is in the range of 0.2 parts per million volume to saturation levels in the gaseous feed stream.
14. The process of claim 1 , wherein the gaseous feed stream comprises hydrocarbons and H 2 O, wherein the H 2 O is in the range of 100 parts per million volume to 1500 parts per million volume.
15. The process of claim 1 , further comprising:
passing the product stream from the adsorbent bed unit to a liquefied natural gas (LNG) process unit; and
separating a flash fuel stream from the LNG process unit and utilizing the flash fuel stream from the LNG process unit as at least a portion of the slip stream.
16. The process of claim 1 , further comprising:
passing the product stream from the adsorbent bed unit to a cryogenic natural gas liquid recovery (NGL) process unit; and
separating an overhead stream from the NGL process unit and utilizing the overhead stream from the NGL process unit as at least a portion of the slip stream.
17. The process of claim 1 , wherein the cycle duration is greater than 2 seconds and less than 800 seconds.
18. The process of claim 1 , wherein the external gas stream is a nitrogen containing stream having greater than one volume percent nitrogen based on the total volume of the feed stream.
19. The process of claim 1 , wherein the external gas stream comprises a predominately nitrogen stream comprising less than 0.1 ppm of water.
20. The process of claim 1 , wherein the external gas stream comprises a predominately nitrogen stream comprising less than 10 ppm of water.
21. The process of claim 1 , wherein the external gas stream comprises at least one of nitrogen, methane, helium, hydrogen or any combination thereof.