SEPARATION AND PURIFICATION TECHNOLOGY
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2026
·
IF 9.1
Hong Tian,Jiwen Fu,Lei Liu,Hongyu Chen,Zheng Zeng,Sijin Chen,Fubin Ma
With moderate N content and rich micropore, NC-AC shows the highest CO 2 uptake. • N-doping and pore structure control low/high-pressure CO 2 sorption, respectively. • Optimal pore size for CO 2 adsorption increases with adsorption pressure. • Pyrrolic N exhibits the most significant enhancement in CO 2 adsorption. In steam methane reforming (SMR) for hydrogen production, efficient CO 2 removal is essential. Although ultra-micropores and nitrogen doping enhance CO 2 adsorption on carbon adsorbents, their combined effects under high-pressure conditions remain unclear. Herein, a nitrogen-doped biochar (NC), an activated biochar (AC), and a nitrogen-doped activated carbon (NC-AC) were prepared from waste coconut shell. AC exhibited a highly developed pore structure (specific surface area of 1755 m 2 /g and micropore volume of 0.644 cm 3 /g), whereas NC was rich in nitrogen content (16.49 wt%). NC-AC combined a moderate nitrogen content (3.06 wt%) with an abundant porous network. High-pressure CO 2 adsorption isotherms revealed a pressure-dependent evolution in the relative contributions of nitrogen-containing functional groups and pore structure: the contribution of nitrogen-containing functional groups was more pronounced at low pressures (<0.5 bar), the contribution of pore structure gradually increased at intermediate pressures (0.5–2 bar), and pore structure played a more pronounced role at high pressures (>2 bar). Dynamic column breakthrough experiments with a CO 2 /H 2 mixture (20/80 vol%) demonstrated that NC-AC exhibited the highest CO 2 uptake. Molecular simulations showed that at low pressure, the 0.6 nm pore exhibited the highest CO 2 adsorption, while at 10 bar, the 0.8 nm pore surpassed due to its strong interaction forces and large packing space. In the 0.8–1.0 nm pores, CO 2 preferentially formed multilayer adsorption near the pore walls and pushed H 2 toward the pore center. Among nitrogen-functional groups, pyrrolic N (N-5) significantly enhanced the CO 2 adsorption capacity and selectivity. Download: Download high-res image (94KB) Download: Download full-size image
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DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 7
·1080
·
IF 3.9
Shiyuan Lin,Ruosong He,Wenhang Wang,Yang Wang,Yongqiang Gu,Qiang Liu,Mingbo Wu
The abundant C1 source CO2can be utilized to produce value-added chemicals through hydrogenation technology. A bifunctional catalyst consisting of reducible metal oxide Cr2O3and acidic zeolite ZSM-5 was designed for the direct conversion of CO2+ H2into valuable aromatics, especially para-xylene (PX), via the methanol-mediated pathway. The twin structure of ZSM-5 (ZSM-5T), with sinusoidal channels that are predominantly exposed to the external surface, enhances the possibility of the transformation of methanol into PX due to the favorable diffusion dynamic of PX in the sinusoidal channels. Via the bifunctional catalyst Cr2O3&ZSM-5T, a PX selectivity of 28.7% and PX space-time yield (STY) of 2.5 gCH2h−1kgcat−1are achieved at a CO2conversion rate of 16.5%. Furthermore, we rationally modify the ZSM-5Tzeolite via Cu species doping and amorphous SiO2shell coating (Cu-ZSM-5T@SiO2). After combining with the Cr2O3catalytic component, the CO2conversion (18.4%) and PX selectivity (33.8%) are increased to some extent, which systematically increases the STY of PX to 3.0 gCH2h−1kgcat−1. The physicochemical property of the acidic zeolite and the corresponding structure-function relationship in enhancing the PX productivity are discovered. Our work provides a novel catalyst design idea to boost PX synthesis performance from CO2hydrogenation.Keywords:CO2hydrogenation;bifunctional catalysts;para-xylene;H-ZSM-5 zeolites
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DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2026
·
IF 2.7
Yufan Ma,Cong Liu,Hongxing Wang,Jie Li,Qingli Qian
The solubilities of CO 2 , H 2 , and CH 4 in 1-ethyl-2-pyrrolidone (NEP) were measured using the isochoric saturation method at 413.15–453.15 K under pressures of 0.45–3.89 MPa (CO 2 ), 4.42–7.64 MPa (H 2 ), and 0.59–3.49 MPa (CH 4 ). The reliability of the apparatus was verified by measuring CO 2 solubility in N-methyl-2-pyrrolidone (NMP) at 323.15–353.15 K. The solubility order in NEP was found to be CO 2 > CH 4 > H 2 . Temperature-dependent Henry’s constants were obtained, and the experimental data were correlated using the Krichevsky–Kasarnovsky equation and the generic Redlich–Kwong (RK) cubic equation of state, with the RK model providing better accuracy. These results offer essential thermodynamic data for describing gas–liquid equilibrium in NEP and support solvent selection and process design in high-temperature CO 2 conversion systems.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Xiaochang Cao,Haoqing Xu,Songlin Dong,Jiayou Xu,Zhihua Qiao,Song Zhao,Jixiao Wang,Zhi Wang
In this work, we proposed a simple method to prepare high-performance and pressure-resistant mixed matrix membranes (MMMs) for CO 2 /H 2 separation. The groups or segments of poly-(vinylamine) (PVAm) were used to modify covalent organic frameworks (COFs), and COFs with similar frameworks but different surfaces were obtained. Then, modified COFs were mixed with PVAm matrix and used to coat the modified-polysulfone (mPSf) to prepare MMMs for CO 2 /H 2 separation. Modified COFs and the PVAm matrix were highly compatible because COF surfaces possessed the same groups or segments as PVAm. Meanwhile, in the coating solution, COF surfaces were found to induce penetration of PVAm molecules into COF pores, narrowing the pore size of the COFs and providing an amino environment for CO 2 preferential absorption and transport. The penetration degree was affected by the hydrogen bond between COF surfaces and the PVAm molecules. In addition, the incorporated COFs effectively restricted the mobility of the PVAm matrix, increasing the pressure resistance for MMMs under high pressure. In the gas permeation test, the optimal MMMs could achieve a CO 2 permeance of 957 GPU and a CO 2 /H 2 selectivity of 17.1 at 2.0 MPa because of the high compatibility and size of the channels (0.94 nm).
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高影响因子
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