Preparation of fiber-like nanoporous carbon from jute thread waste for superior CO2 and H2S removal from natural gas: Experimental and DFT study

Abstract In the present study, a novel N-S rich nanoporous carbon based on jute thread waste (JW) as a prevalent cellulosic biomass in order to remove CO2 and H2S from gaseous stream has been successfully synthesized and fabricated. For this end , we synthesized a series of jute-derived nanoporous carbon (JW-NC) samples with different KOH/C ratios (i.e., 3, 4 and 5), synthesis temperatures (i.e., 700, 800 and 900 ˚C) and times (i.e., 60, 90 and 120 min).The results indicated that JW-NC nanoadsorbents have been mainly composed of carbon nanofibers, and provided high surface area (up to 2579.55 m2/g) with excellent pore volume (up to 1.50 cm3/g) . As experimentally investigated JW-NC nanoadsorbents displayed an extra-high CO2 and H2S adsorption capacity at 1 bar (8.05 mmol/g for CO2 and 17.19 mmol/g for H2S), 10 bar (20.53 mmol/g for CO2 and 29.26 mmol/g for H2S) and 35 bar (30.36 mmol/g for CO2 and 40.41 mmol/g for H2S). The results obtained by the density functional theory (DFT) method showed that the Pyrrolic-N atoms affect the pores significantly and play an important role for gas adsorption in all cases. However, the presence of S atoms around Pyrrolic-N atoms in the pores could change the adsorption mechanisms, from which the chemisorption of H2S (Ead = -336.28 kJ.mol-1) changed interestingly to physisorption (Ead = -23.92 kJ.mol-1) as increased S/N ratio of the adsorbent. To sum up , the high gas adsorption capacity, along with excellent cyclic performance and superior preferential gas adsorption, make JW-NC nanoadsorbents as a viable and cost-effective candidate for large-scale natural gas purification.