Adsorbent material, adsorption system, and adsorption process for hydrogen recovery
An adsorption system having at least one adsorber retaining a bed of adsorbent material can be configured to provide enhanced purification of fees having relatively low concentrations of hydrogen or helium. Embodiments can utilize an activated carbon layer between at least one upstream layer and at least one downstream layer. The activate carbon layer can include activated carbon can have a pre-selected surface area (SA), bulk density, total open pore volume (TOPV), and/or ratio of TOPV to surface area (TOPV/SA).
1 . A process for adsorption, comprising:
positioning a bed of adsorbent material within a vessel of an adsorber, the bed of adsorbent material comprising an activated carbon layer including activated carbon, the activated carbon of the activated carbon layer having:
(i) a surface area (SA) that ranges from 380 m 2 /g to 750 m 2 /g; and
(ii) a total open pore volume (TOPV) to SA ratio (TOPV/SA), which has a value greater than 0.59 nm and less than 0.83 nm;
passing a feed fluid flow through the bed of adsorbent material to purify the feed fluid;
outputting a purified fluid flow from the vessel after the feed fluid flow has passed through the bed of adsorbent material; and wherein the feed fluid has a hydrogen content of less than 79 volume percent (vol %) to output a purified fluid flow having a hydrogen content of greater than or equal to 95 vol %.
2 . The process of claim 1 , wherein the activated carbon also has:
(iii) a carbon dioxide (CO2) isosteric heat of adsorption at 0.5 millimoles per gram (mmol/g) surface coverage that can be less than or equal to 23.39 kilojoules per mole (kJ/mol) and greater than 0 kJ/mol; and
(iv) a TOPV that is 0.53 cubic centimeters per gram (cc/g) or less; and
wherein the activated carbon layer has a bulk density that is greater than or equal to 0.60 grams per cubic centimeter (g/cc).
3 . The process of claim 1 , wherein the activated carbon also has:
(iii) a particulate size range that is between 1 millimeter (mm) in diameter and 5 mm in diameter.
4 . The process of claim 1 , wherein the activated carbon layer also has a bulk density that is between 0.53 grams per cubic centimeter (g/cc) and 0.62 g/cc.
5 . The process of claim 4 , wherein the activated carbon also has:
(iii) a carbon dioxide (CO2) isosteric heat of adsorption at 0.5 millimole per gram (mmol/g) surface coverage that can be less than or equal to 23.39 kilojoules per mole (kJ/mol) and greater than 0 kJ/mol; and/or
(iv) a TOPV that is between 0.50 cubic centimeters per gram (cc/g) and 0.40 cc/g.
6 . The process of claim 4 , wherein the activated carbon also has:
(iii) a carbon dioxide (CO2) isosteric heat of adsorption at 0.5 millimoles per gram (mmol/g) surface coverage that can be less than or equal to 23.39 kilojoules per mole (kJ/mol) and greater than 0 kJ/mol; and/or
(iv) a TOPV that is between 0.45 cubic centimeters per gram (cc/g) and 0.62 cc/g.
7 . The process of claim 1 , wherein the activated carbon also has a TOPV that is between 0.40 cubic centimeters per gram (cc/g) and 0.50 cc/g.