Carbon pyrolyzate adsorbent having utility for CO
View Patent ↗A particulate form carbon pyrolyzate adsorbent, having the following characteristics: (a) CO 2 capacity greater than 105 cc/gram at one bar pressure and temperature of 273° Kelvin; (b) CO 2 Working Capacity greater than 7.0 weight percent; (c) CO 2 heats of adsorption and desorption each of which is in a range of from 10 to 50 kJ/mole; and (d) a CO 2 /N 2 Henry's Law Separation Factor greater than 5. The carbon pyrolyzate material can be formed from a polyvinylidene chloride-based polymer or copolymer, or other suitable resin material, to provide an adsorbent that is useful for carbon dioxide capture applications, e.g., in treatment of flue gases from coal-fired power generation plants.
1. A carbon pyrolyzate adsorbent, having the following characteristics: (a) CO.sub.2 capacity greater than 105 cc/gram at one bar pressure and temperature of 273.degree. Kelvin; (b) CO.sub.2 Working Capacity greater than 7.0 weight percent; (c) CO.sub.2 heats of adsorption and desorption each of which is in a range of from 10 to 50 kJ/mole; and (d) a CO.sub.2/N.sub.2 Henry's Law Separation Factor greater than 5.
2. The adsorbent of claim 1 , having an average particle diameter greater than 50 μm.
3. The adsorbent of claim 1 , comprising particles of diameter in a range of from 150 to 500 μm.
4. The adsorbent of claim 1 , having a bulk density greater than 0.55 g/mL.
5. The adsorbent of claim 1 , having a water adsorptive capacity of less than 5% by weight, based on weight of the adsorbent, at 303° Kelvin and 40% relative humidity.
6. The adsorbent of claim 1 , having porosity characterized by average pore size below 1 nm.
7. The adsorbent of claim 1 , having porosity at least 50% of the pore volume of which is constituted by pores in a pore size range of from 0.35 to 0.7 nm.
8. The adsorbent of claim 1 , having an attrition rate index less than 1 wt %/hr as measured by the procedure of ASTM D 5757.
9. The adsorbent of claim 1 , having an N 2 BET surface area of at least 800 m 2 per gram.
10. The adsorbent of claim 1 , having an N 2 micropore volume of at least 0.2 milliliters per gram.
11. The adsorbent of claim 1 , wherein the adsorbent is a pyrolyzate of a PVDC homopolymer or a PVDC copolymer.
12. The adsorbent of claim 1 , characterized by CO 2 capture recovery of at least 90% and CO 2 capture purity of at least 90%, when contacted with a simulated flue gas composition comprising air containing 15% CO 2 and saturated with water vapor, at 383° Kelvin and volumetric flow rate of 100 L/minute of simulated flue gas composition per liter of bed of the adsorbent.
13. The adsorbent of claim 1 , characterized by CO 2 heats of adsorption and desorption each of which is in a range of from 10 to 50 kJ/mole.
14. A method of making a carbon material for CO 2 capture, said method comprising pyrolyzing a polymeric or copolymeric resin material under conditions that are effective to yield a carbon pyrolyzate material having the following characteristics:
(a) CO 2 capacity greater than 105 cc/gram at one bar pressure and temperature of 273° Kelvin;
(b) CO 2 Working Capacity greater than 7.0 weight percent;
(c) CO 2 heats of adsorption and desorption each of which is in a range of from 10 to 50 kJ/mole; and
(d) a CO 2 /N 2 Henry's Law Separation Factor greater than 5.
15. The method of claim 14 , wherein the resin comprises a PVDC homopolymer or a PVDC copolymer.
16. A CO 2 capture apparatus, comprising a carbon adsorbent according to claim 1 , arranged for contacting CO 2 -containing fluid under conditions effecting adsorption of CO 2 on the carbon pyrolyzate adsorbent.
17. The CO 2 capture apparatus of claim 16 , comprising a pressure swing adsorption system, a thermal swing adsorption system, or a vacuum swing adsorption system.
18. The CO 2 capture apparatus of claim 16 , wherein the apparatus is adapted to regenerate the carbon pyrolyzate adsorbent after it has become at least partially loaded with CO 2 .
19. A CO 2 capture method, comprising contacting a CO 2 -containing fluid with a carbon adsorbent according to claim 1 under conditions effecting adsorption of CO 2 on the carbon pyrolyzate adsorbent.
20. The CO 2 capture method of claim 19 , further comprising regenerating the carbon pyrolyzate adsorbent after it has become at least partially loaded with CO 2 .