Carbon pyrolyzate adsorbent having utility for CO

1. A carbon pyrolyzate adsorbent, comprising a pyrolyzate of a PVDC copolymer, wherein the PVDC copolymer comprises a copolymer of an acrylic acid ester, said 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.

2. The adsorbent of claim 1 , wherein the acrylic acid ester comprises methyl acrylate.

3. The adsorbent of claim 1 , comprising particles of diameter in a range of from 10 to 500 μm.

4. The adsorbent of claim 1 , comprising particles having a median particle diameter in a range of from 200 to 350 μm.

5. The adsorbent of claim 1 , having a water sorptive 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 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.

7. The adsorbent of claim 1 , having porosity characterized by a median pore width below 1 nm.

8. The adsorbent of claim 1 , having a nitrogen BET surface area of at least 800 m 2 per gram.

9. The adsorbent of claim 1 , having a nitrogen micropore volume of at least 0.2 mL per gram.

10. 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.

11. The adsorbent of claim 1 , wherein the adsorbent has at least one additional compatible characteristic selected from the group consisting of:

(e) being a pyrolyzate of homopolymer PVDC, PVDC-MA copolymer, PVDC-polyvinyl chloride (PVDC-PVC) copolymers, polyfurfuryl alcohol, polyacrylonitrile, and polymers containing heteroatoms that upon carbonization are left as dispersed species throughout the carbon material;

(f) an average particle diameter greater than 50 μm;

(g) particle diameter in a range of from 10 to 500 μm;

(h) particle diameter in a range of 150 to 500 μm;

(i) median particle diameter in a range of from 200 to 350 μm;

(j) bulk density greater than 0.55 g/mL;

(k) CO 2 heats of adsorption and desorption each of which is in a range of from 20 to 30 kJ/mole;

(l) water adsorptive capacity of less than 5% by weight, based on weight of the adsorbent, at 303° Kelvin and 40% relative humidity;

(m) average pore size below 1 nm;

(n) 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;

(o) porosity characterized by a median pore width below 1 nm;

(p) an attrition rate index less than 1 wt %/hr as measured by the procedure of ASTM D 5757;

(q) N 2 BET surface area of at least 800 m 2 per gram;

(r) N 2 BET surface area of at least 900 m 2 per gram;

(s) N 2 BET surface area of at least 1000 m 2 per gram;

(t) N 2 micropore volume of at least 0.2 mL per gram;

(u) N 2 micropore volume in a range of from 0.3 to 0.6 mL per gram;

(v) 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 a bed of the adsorbent;

(w) being a pyrolyzate of homopolymer PVDC, PVDC-MA copolymer having a weight average molecular weight in a range of from 80,000 to 100,000;

(x) bulk density greater than 0.55 grams per cubic centimeter;

(y) bulk density greater than 0.9 grams per cubic centimeter;

(z) bulk density in a range of from about 1.0 to about 2.2 grams per cubic centimeter;

(aa) being in a form of granules;

(ab) being in a bead form;

(ac) being in a form of a monolith;

(ad) being in a cylindrical form;

(ae) being in a disc form;

(af) being of porous, non-graphitized carbon;

(ag) N 2 BET surface area being in a range of from tw m 2 per gram;

(ah) having porosity, substantially all of which is in pores <2 nm in diameter;

(ai) CO 2 capacity greater than 120 volumes of CO 2 /volume of carbon pyrolyzate adsorbent as measured at 273° Kelvin and 1 atmosphere pressure;

(aj) CO 2 capacity greater than 130 volumes of CO 2 /volume of carbon pyrolyzate adsorbent as measured at 273° Kelvin and 1 atmosphere pressure;

(ak) CO 2 capacity of at least 20 wt % at 1 atm CO 2 , based on weight of the adsorbent;

(al) CO 2 adsorption activation energy less than 5 kJ/mole;

(am) CO 2 heats of adsorption and desorption each of which is in a range of from 25 to 28 kJ/mole;

(an) CO 2 being desorbable from the adsorbent with steam;

(ao) adsorbent lifetime of at least 50,000 adsorption/desorption cycles for adsorption and desorption of CO 2 ;

(ap) being in a form of spherical adsorbent granules;

(aq) being in a form of spherical adsorbent granules 100 to 300 μm in diameter;

(ar) non-agglomerable or sinterable at 100° C.;

(as) being of hydrophobic character;

(at) CO 2 capacity of at least 100 volumes of CO 2 /volume of carbon material, as measured at 273° Kelvin and 1 atmosphere pressure;

(au) being >40% by volume micropores;

(av) having at least 50% of pore volume in pores <0.7 nm;

(aw) a separation factor greater than 6 for CO 2 over N 2 ;

(ax) a separation factor in a range of from 6.2 to 7.5 for CO 2 over N 2 ;

(ay) a permeability for CO 2 greater than 900 cc/psi/cm 2 /min;

(az) a permeability for CO 2 in a range of from 910 to 1250 cc/psi/cm 2 /min; and

(ba) an attrition rate index <0.01 wt % per hour in a downflow reactor.

12. A method of making an adsorbent for carbon capture, said method comprising pyrolyzing a PVDC copolymer, wherein the PVDC copolymer comprises a copolymer of an acrylic acid ester, 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.

13. The method of claim 12 , wherein the acrylic acid ester comprises methyl acrylate.

14. The method of claim 12 , wherein the PVDC copolymer comprises a PVDC-MA copolymer having a weight average molecular weight in a range of from 80,000 to 100,000.

15. The method of claim 12 , wherein said pyrolyzing is conducted at temperature in a range of from 600° C. 2 900° C. under inert atmosphere.

16. The method of claim 15 , followed by exposing the carbon pyrolyzate material to an oxidizing atmosphere at temperature above 250° C.

17. A CO2 capture apparatus, comprising the carbon pyrolyzate adsorbent of claim 1 in a reactor configured for contacting of the carbon pyrolyzate adsorbent with CO2-containing gas.

18. The CO2 capture apparatus of claim 17 , configured for regeneration of the carbon pyrolyzate adsorbent after it has been loaded to a predetermined extent with CO2 in said contacting.

19. The CO2 capture apparatus of claim 17 , comprising a moving bed contacting system for said contacting of the carbon pyrolyzate adsorbent with CO2-containing gas.

20. A method of capturing CO2 from CO2-containing gas, said method comprising contacting the CO2-containing gas with a carbon pyrolyzate adsorbent according to claim 1 .