http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Enhanced SF6 recovery by hierarchically structured MFI zeolite
Chong Yang Chuah,유수연,나경수,배태현 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.62 No.-
A hierarchical zeolite MFI has been synthesised and investigated for its potential feasibility in SF6/N2 separation. Zeolite MFI possessing a hierarchical microporous–mesoporous structure (MFI-2) displayed an enhanced SF6/N2 selectivity at 40 °C as compared to bulk MFI (MFI-1). More importantly, at both 25 and 40 °C, drastically improved SF6 adsorption kinetics were observed for MFI-2, owing to the presence of mesopores that can facilitate the transport of SF6 within the sorbent. Such improved adsorption kinetics allows a rapid adsorption–desorption cycling in an industrial process, which was proven by the breakthrough analysis. Furthermore, MFI-2 was found to have a much lower isosteric heat of adsorption than MFI-1, indicating its feasibility in the industrial operation as it does not require a large energy penalty for regeneration. Further evaluation with an idealised vacuum swing adsorption (VSA) model revealed that MFI-2 can exhibit more competitive performance at 40 °C than at room temperature.
Chuah, Chong Yang,Li, Wen,Samarasinghe, S.A.S.C.,Sethunga, G.S.M.D.P.,Bae, Tae-Hyun Elsevier 2019 Microporous and mesoporous materials Vol.290 No.-
<P><B>Abstract</B></P> <P>HKUST-1 nanocrystals with large accessible surface areas and high porosity were functionalized with amine groups and incorporated into polymer matrices to form mixed-matrix membranes for application in CO<SUB>2</SUB> capture. This gas permeation study reveals that pristine HKUST-1 nanocrystals are able to increase the gas permeabilities of polymer membranes with no noticeable effect on CO<SUB>2</SUB>/N<SUB>2</SUB> selectivity as a result of their high porosity and large pore dimensions. Contrarily, 20 wt% amine-functionalized HKUST-1 can improve the CO<SUB>2</SUB>/N<SUB>2</SUB> selectivity of polymer membranes by as much as 38%. As shown in a detailed analysis of the diffusivity-solubility, the amine-functionalized HKUST-1 suppressed N<SUB>2</SUB> solubility and diffusivity but enhanced CO<SUB>2</SUB> diffusivity. This resulted in an increased CO<SUB>2</SUB>/N<SUB>2</SUB> perm-selectivity. Meanwhile, the pristine HKUST-1 nanocrystals increased the diffusivity and solubility of both species in a non-selective manner. These results indicate the feasibility of tuning the CO<SUB>2</SUB> separation performance of mixed-matrix membranes by introducing amine functionality into the filler.</P> <P><B>Highlights</B></P> <P> <UL> <LI> HKUST-1 and amine-functionalized HKUST-1 nanocrystals were successfully synthesized. </LI> <LI> HKUST-1 nanocrystals improved CO<SUB>2</SUB> permeability with no effect on CO<SUB>2</SUB> selectivity. </LI> <LI> Amine-functionalized HKUST-1 enhanced CO<SUB>2</SUB>/N<SUB>2</SUB> selectivity and CO<SUB>2</SUB> permeability. </LI> <LI> Amine-functionalized HKUST-1 suppressed N<SUB>2</SUB> solubility and diffusivity substantially. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Enhanced SF<sub>6</sub> recovery by hierarchically structured MFI zeolite
Chuah, Chong Yang,Yu, Suyeon,Na, Kyungsu,Bae, Tae-Hyun Elsevier 2018 Journal of industrial and engineering chemistry Vol.62 No.-
<P><B>Abstract</B></P> <P>A hierarchical zeolite MFI has been synthesised and investigated for its potential feasibility in SF<SUB>6</SUB>/N<SUB>2</SUB> separation. Zeolite MFI possessing a hierarchical microporous–mesoporous structure (MFI-2) displayed an enhanced SF<SUB>6</SUB>/N<SUB>2</SUB> selectivity at 40°C as compared to bulk MFI (MFI-1). More importantly, at both 25 and 40°C, drastically improved SF<SUB>6</SUB> adsorption kinetics were observed for MFI-2, owing to the presence of mesopores that can facilitate the transport of SF<SUB>6</SUB> within the sorbent. Such improved adsorption kinetics allows a rapid adsorption–desorption cycling in an industrial process, which was proven by the breakthrough analysis. Furthermore, MFI-2 was found to have a much lower isosteric heat of adsorption than MFI-1, indicating its feasibility in the industrial operation as it does not require a large energy penalty for regeneration. Further evaluation with an idealised vacuum swing adsorption (VSA) model revealed that MFI-2 can exhibit more competitive performance at 40°C than at room temperature.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Zeolite MFI crystal with hierarchical structure was successfully synthesised. </LI> <LI> Hierarchical zeolite MFI (MFI-2) displayed enhanced SF<SUB>6</SUB> adsorption kinetics as compared to bulk MFI (MFI-1). </LI> <LI> MFI-2 showed lower isosteric heat of adsorption than MFI-1, thus allowing a lower energy penalty for adsorptive separation process. </LI> <LI> The MFI-2 exhibited a competitive performance in an idealised VSA model at 40°C. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Yanqin Yang,Chong Yang Chuah,Tae-Hyun Bae 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.88 No.-
Post-combustion CO2 capture from large point sources has been proposed as a promising technology toprevent growth of the level of atmospheric CO2 and thus restrict the progress of global warming. However, CO2 capture technology is economically unfeasible at present due to the high cost and largeenergy penalty. Therefore, the development of cost-effective CO2 capture technologies has attracted keeninterest. Herein, we develop a series of amine-functionalized adsorbents via one-step amine grafting ofcost-effective porous polymers containing unreacted chloromethyl groups, which are prepared fromfivedi- or trichloromethyl monomers via Friedel–Crafts alkylation. Among the adsorbents prepared, PTP-DETA possesses the highest CO2 uptake capacity and CO2/N2 selectivity owing to the highest amineloading. In contrast, the highly porous adsorbent PBP-DETA presents the fastest adsorption kinetics butpoorest CO2 capture performance. Nevertheless, subsequent breakthrough experiments revealed that allamine-functionalized adsorbents retain attractive CO2 adsorption properties under dynamicflowconditions even in the presence of moisture.
High performance composite membranes comprising Zn(pyrz)2(SiF6) nanocrystals for CO2/CH4 separation
Heqing Gong,Chong Yang Chuah,Yanqin Yang,배태현 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.60 No.-
Nanocsrystals of Zn(pyrz)2(SiF6) (or SIFSIX-3-Zn) metal-organic framework were synthesized by a facile sonochemical means and incorporated into a polyimide membrane to realize an excellent CO2/CH4 separation performance. Zn(pyrz)2(SiF6) nanocrystals selectively took up a large amount of CO2 even at low pressure while negligible uptake was observed for CH4. This implies that Zn(pyrz)2(SiF6) is an ideal filler to improve CO2/CH4 separation performance of polymer membrane via selective transport of CO2 over CH4. Subsequently, high-quality mixed-matrix membranes that are free of filler/polymer interfacial voids were successfully fabricated by employing house-made polyimide as a polymer matrix. Binary CO2/CH4 mixture gas permeation tests revealed that both CO2 permeability and CO2/CH4 selectivity of mixed-matrix membranes, especially for the membrane with 20 wt% filler loading, were significantly improved compared to those of pure polymeric membrane owing to the selective CO2 uptake and transport by Zn(pyrz)2(SiF6) crystals. As a result, a high performance surpassing the upper bound limit for polymeric membranes was achieved.
Wen Li,Chong Yang Chuah,Lina Nie,배태현 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.74 No.-
A three-dimensional NiDOBDC/GO composite with an optimized accessible surface area was successfullysynthesized and incorporated into a polyimide membrane to improve CO2/CH4 separation performancewhile keeping good mechanical strength. A significant increase in CO2/CH4 selectivity (59%) was observedfor the case of 20% NiDOBDC/GO composite in Matrimid1 membrane, without sacrificing CO2permeability. Furthermore, the incorporation of the NiDOBDC/GO composite in a polymeric membranewas found to improve the overall mechanical strength of resulting mixed-matrix membranes. Therefore,the addition of the nanocomposites asfillers in polymeric membranes is proposed as a promisingstrategy to realize major improvements in CO2/CH4 separation.