Preparation of a highly microporous carbon from a carpet material and its application as CO2 sorbent

In order to increase the use of carpet wastes (pre- and/or post-consumer wastes), this work studies for the first time the preparation and characterisation of a microporous material from a commercial carpet (pile fiber content: 80% wool/20% nylon; primary and secondary backings: woven polypropylene; binder: polyethylene) and its application for CO2 capture. The porous material was prepared from an entire carpet material using a standard chemical activation with KOH and then, characterised in terms of their porous structure and surface functional groups. Adsorption of CO2 was studied using a thermogravimetric analyser at several temperatures (25–100 °C) and under different CO2 partial pressures (i.e. pure CO2 flow and a ternary mixture of 15% CO2, 5% O2 and 80% N2). In order to examine the adsorbent regenerability, multiple CO2 adsorption/desorption cycles were also carried out. The surface area and micropore volume of the porous adsorbent were found to be 1910.17 m2 g- 1 and 0.85 cm3 g- 1, respectively. The CO2 adsorption profiles illustrate that the maximum CO2 capture on the sample was reached in less than 10 min. CO2 adsorption capacities up to 8.41 wt.% and 3.37 wt.% were achieved at 25 and 70 °C, respectively. Thermal swing regeneration studies showed that the prepared adsorbent has good cyclic regeneration capacities.