Efficiently Integrated Desulfurization from Natural Gas over Zn-ZIF-Derived Hierarchical Lamellar Carbon Frameworks

Abstract

Selective removal of carbonyl sulfide (COS) and hydrogen sulfide (H 2 S) is the key step for natural gas desulfurization due to the highly toxic and corrosive features of these gaseous sulfides, and efficient and stable desulfurizers are urgently needed in the industry. Herein, we report a class of nitrogen-functionalized, hierarchically lamellar carbon frameworks (N-HLCF-xs), which are obtained from the structural transformation of Zn zeolitic imidazolate frameworks via controllable carbonization. The N-HLCF-xs possess the desirable characteristics of large Brunauer−Emmett−Teller surface areas (645−923 m 2 /g), combined primary three-dimensional microporosity and secondary two-dimensional lamellar microstructure, and high density of nitrogen base sites with enhanced pyridine ratio (17.52 wt %, 59.91%). The anchored nitrogen base sites in N-HLCF-xs show improved accessibility, which boosts their interaction with acidic COS and H 2 S. As expected, N-HLCF-xs can be employed as multifunctional and efficient desulfurizers for selective removal of COS and H 2 S from natural gas. COS was first transformed into H 2 S via catalytic hydrolysis, and the produced H 2 S was then captured and separated and catalyzed oxidation into elemental sulfur. The above continuous processes can be achieved with solo N-HLCF-xs, giving extremely high efficiencies and reusability. Their integrated desulfurization performance was better than many desulfurizers used in the area, such as activated carbon, β zeolite, MIL-101(Fe), K 2 CO 3 /γ-Al 2 O 3 , and FeO x /TiO 2 .

Advances in Resources Recovery of H2S: A Review of Desulfurization Processes and Catalysts

“…Zhang et al reported a series of nitrogen-functionalized hierarchically lamellar carbon frameworks (N-HLCF-xs), which showed a high density of nitrogen base sites (17.52 wt %) and pyridine ratio (59.91%) with a large BET surface area (645−923 m 2 /g). 121 As an efficient and multifunctional desulfurizer for the removal of H 2 S and COS, the N-HLCFxs displayed nearly 100% COS and H 2 S conversion at 70 and 120 °C, respectively. Long's group synthesized N-doped mesoporous carbon by using a traditional colloidal silica nanocasting technology (Figure 3c).…”

“…More importantly, it presented a high regeneration performance with a sulfur capacity of 369.1 mg/g after five regeneration cycles, and S was the main product. Recently, Zhang and coauthors reported the synthesis of N-functionalized hierarchically lamellar carbon frameworks (N-HLCF-xs) via controllable carbonization of Zn zeolitic imidazolate frameworks . The N-HLCF-xs exhibited a large S BET (645–923 m 2 /g) and high density of nitrogen base sites with enhanced pyridine ratio (17.52 wt %, 59.91%).…”

“…Copyright 2013 American Chemical Society. (d) Nitrogen-functionalized, hierarchically lamellar carbon frameworks for the selective removal of COS and H 2 S. Reproduced from ref . Copyright 2022 American Chemical Society.…”

“…Besides, the HNMCs displayed good catalytic durability in the run of 80 h. Due to the fact that the concentration of the HS – ion is determined by the alkalinity of the catalyst, the N content of mesoporous carbon is crucial for the catalytic performance. Zhang et al reported a series of nitrogen-functionalized hierarchically lamellar carbon frameworks (N-HLCF-xs), which showed a high density of nitrogen base sites (17.52 wt %) and pyridine ratio (59.91%) with a large BET surface area (645–923 m 2 /g) . As an efficient and multifunctional desulfurizer for the removal of H 2 S and COS, the N-HLCF-xs displayed nearly 100% COS and H 2 S conversion at 70 and 120 °C, respectively.…”

“…the121 The N-HLCF-xs exhibited a large S BET (645−923 m 2 /g) and high density of nitrogen base sites with enhanced pyridine ratio (17.52 wt %, 59.91%). As expected, N-HLCF-xs were applied as efficient and multifunctional desulfurizers for the selective removal of acidic H 2 S and COS (Figure3d).…”