Polyethyleneimine-impregnated activated carbon nanofiber composited graphene-derived rice husk char for efficient post-combustion CO₂capture

Abstract

This study presents the fabrication of polyethyleneimine (PEI)–graphene-derived rice husk char (GRHC)/activated carbon nanofiber (ACNF) composites via electrospinning and physical activation processes and its adsorption performance toward CO2. This study was performed by varying several parameters, including the loading of graphene, impregnated and nonimpregnated with amine, and tested on different adsorption pressures and temperatures. The resultant ACNF composite with 1% of GRHC shows smaller average fiber diameter (238 ± 79.97 nm) with specific surface area (S BET) of 597 m2/g, and V micro of 0.2606 cm3/g, superior to pristine ACNFs (202 m2/g and 0.0976 cm3/g, respectively). ACNF/GRHC0.01 exhibited CO2 uptakes of 142 cm3/g at atmospheric pressure and 25°C, significantly higher than that of pristine ACNF’s 69 cm3/g. The GRHC/ACNF0.01 was then impregnated with PEI and further achieved impressive increment in CO2 uptake to 191 cm3/g. Notably, the adsorption performance of CO2 is directly proportional to the pressure increment; however, it is inversely proportional with the increased temperature. Interestingly, both amine-impregnated and nonimpregnated GRHC/ACNFs fitted the pseudo first-order kinetic model (physisorption) at 1 bar; however, best fitted the pseudo second-order kinetic model (chemisorption) at 15 bar. Both GRHC/ACNF and PEI-GRHC/ACNF samples obeyed the Langmuir adsorption isotherm model, which indicates monolayer adsorption. At the end of this study, PEI-GRHC/ACNFs with excellent CO2 adsorption performance were successfully fabricated.

Measuring Physical Properties of Electrospun Nanofiber Mats for Different Biomedical Applications

“…To evaluate these curves, it is necessary to differentiate between the different adsorption isotherms. Many nanofiber mats reported in the literature belong to type IV [ 95 ], while type I or a pressure-dependent change between these types are also found [ 96 , 97 ]. Differentiation between the different types of adsorption isotherms is possible by fitting a range of possible equations to the measured curves, while a first idea of the type can already be gained by looking at the slopes of the measured adsorption–desorption curves ( Figure 2 ) [ 98 ].…”

The use of electrospun nanofibers for absorption and separation of carbon dioxide: A review

“…The fibers retain 91% of their initial CO 2 adsorption capacity after 15 cycles of the adsorption-desorption process. 113 Othman et al 114 present the fabrication of polyethyleneimine (PEI)-graphene-derived rice husk char (GRHC)/activated carbon nanofiber (ACNF) composites via electrospinning and physical activation processes and its adsorption performance toward CO 2 . This study was performed by varying several parameters, including the loading of graphene, impregnated and nonimpregnated with amine, and tested on different adsorption pressures and temperatures.…”

Permeable Membranes PUR/TETA and PUR/TEPA for CO2 Capture Prepared with One-Step Electrospinning Technology

“…Zainab et al [12] synthesized PS/PU nanofiber membranes with hierarchically porous structures, a high surface area of ~62 m 2 •g −1 , and a high CO 2 adsorption capacity of 1.64 mmol•g −1 for the optimized membranes. In the next study, Abbasi et al [13] and many more [14][15][16][17][18][19][20][21][22] developed a new amine-bearing nanofibrous adsorbent (electrospinning of s-PP, RIG of GMA, and amination with EA) for the removal of CO 2 with the highest CO 2 adsorption capacity of 2.87 mmol/g. Other amine-based materials have been reported elsewhere [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38].…”