Process for purifying natural gas and regenerating one or more adsorbers
One exemplary embodiment can be a process for purifying a natural gas by using first and second adsorbers. The process may include passing a feed including the natural gas through the first adsorber to obtain a purified natural gas product, regenerating the second adsorber in a heating stage, and regenerating the second adsorber in a cooling stage. The heating stage may include separating a portion of the feed comprised in a regeneration gas, passing the regeneration gas to a dryer for removing water, heating the regeneration gas with a heater after exiting the dryer, and passing the regeneration gas to the second adsorber to regenerate the second adsorber. The cooling stage may include expelling at initiation of cooling at least a part of a fluid present in the second adsorber to the dryer to desorb water from a molecular sieve in the dryer, and cooling the second adsorber by circulating the regeneration gas bypassing the heater.
1. A process for purifying a natural gas by using first and second adsorbers, comprising:
A) passing a feed comprising the natural gas through the first adsorber to obtain a purified natural gas product;
B) regenerating the second adsorber in a heating stage, wherein the heating stage comprises:
1) separating a portion of the feed comprised in a regeneration gas;
2) passing the regeneration gas to a dryer for removing water;
3) heating the regeneration gas with a heater after exiting the dryer; and
4) passing the regeneration gas to the second adsorber to regenerate the second adsorber; and
C) regenerating the second adsorber in a cooling stage, wherein the cooling stage comprises:
1) expelling at initiation of cooling at least a part of a fluid present in the second adsorber to the dryer to desorb water from an adsorbent in the dryer; and
2) cooling the second adsorber by circulating the regeneration gas bypassing the heater.
2. The process according to claim 1 , wherein the natural gas comprises at least about 70%, by mole, of at least one of methane and ethane.
3. The process according to claim 1 , wherein the natural gas comprises at least about 95%, by mole, of methane.
4. The process according to claim 1 , wherein the natural gas comprises no more than about 2%, by mole, carbon dioxide.
5. The process according to claim 1 , wherein the natural gas comprises no more than about 0.5%, by mole, carbon dioxide.
6. The process according to claim 1 , wherein the natural gas comprises no more than about 7,500 ppm, by volume, water.
7. The process according to claim 1 , wherein the natural gas comprises no more than about 500 ppm, by volume, water.
8. The process according to claim 1 , wherein the regeneration gas comprises at least about 70%, by mole, of at least one of methane and ethane.
9. The process according to claim 1 , wherein the regeneration gas comprises at least about 95%, by mole, of methane.
10. The process according to claim 1 , wherein the regeneration gas comprises no more than about 2%, by mole, carbon dioxide.
11. The process according to claim 1 , wherein the regeneration gas comprises no more than about 0.5%, by mole, carbon dioxide.
12. The process according to claim 1 , wherein the first and second adsorbers contain an adsorbent.
13. The process according to claim 12 , wherein the adsorbent of the first and second adsorbers comprises a zeolite.
14. The process according to claim 1 , wherein the regeneration gas further comprises the purified natural gas product.
15. The process according to claim 1 , wherein the first adsorber operates at a temperature of about 10-about 70° C. and a pressure of about 600-about 12,000 kPa during adsorption.
16. The process according to claim 1 , wherein the second adsorber operates at a temperature of about 120-about 320° C. and a pressure of about 600-about 12,000 kPa during regeneration in the heating stage.
17. The process according to claim 1 , further comprising liquefying the purified natural gas product.