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Optimizing Carbon Dioxide Uptake and Carbon Dioxide‐Methane Selectivity of Oxygen‐Doped Porous Carbon Prepared from Oxygen Containing Polymer Precursors
Author(s) -
Ghosh Saunab,
Barron Andrew R.
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201701712
Subject(s) - carbon dioxide , oxygen , chemistry , selectivity , nuclear chemistry , partial pressure , polymer , adsorption , organic chemistry , catalysis
The reproducible synthesis is reported for oxygen containing porous carbons (OPC) by the KOH activation at 500–800 °C of two oxygen containing precursor polymers: polyfurfuryl alcohol (PFFA) and polyanisyl alcohol (PAA) yielding FFA‐OPC and AA‐OPC, respectively. Both OPCs exhibits good thermal stability and reproducible gas uptake properties over multiple cycles. The surface area and pore volumes of the OPC are independent of the precursor identity, but controlled by the activation temperature. Similarly, the uptake of CO 2 is determined by the physical properties of the OPC: activation at 750 °C results in uptake that equals or out‐performs existing PCs for high pressure uptake (30 bar) at 24.0 °C (FFA‐OPC 750 : 117 wt%; AA‐OPC 750 : 115 wt%). The high uptake is related to a high relative percentage of pores <2 nm. The uptake of CH 4 for both OPCs is greatest for samples activation at 750 °C, FFA‐OPC 750 shows enhanced uptake compared to AA‐OPC 750 , 15.5 wt% versus 13.7 wt%, respectively. Uptake for CH 4 appears to relate to a high relative percentage of pores 1–2 nm, which is observed for AA‐OPC 750 . As a consequence, AA‐OPC 750 demonstrates superior selectivity for CO 2 capture over CH 4 uptake (AA‐OPC 750 : V mass (CO 2 /CH 4 )=8.37 at 30 bar) as compared to reported PCs. A higher value for the isosteric heat of adsorption of CO 2 (33 kJ mol −1 ) versus CH 4 (11 kJ mol −1 ) suggests a new temperature dependent strategy for removing CO 2 from natural gas via selective adsorption and desorption cycles.