02014nas a2200241 4500008004100000245006700041210006700108260000800175300001100183490000700194520127900201653001501480653001901495653002001514653001701534653002001551653001301571100001901584700002401603700002001627700002601647856009901673 2024 eng d00aContinuous flow synthesis of hierarchical low silica X zeolite0 aContinuous flow synthesis of hierarchical low silica X zeolite cJUN a1090470 v393 a

Zeolites, renowned for their versatile applications in catalysis, adsorption, and ion exchange, have long been synthesized using conventional batch processes. However, the inherent limitations of these methods, such as resource-intensive conditions and inconsistent product quality, underscore the need for a sustainable and efficient approach. In this study, a continuous flow synthesis process was established for the synthesis of industrially important low silica X (LSX) zeolite using a tubular reactor. The synthesis gel was subjected to aging for 5 days at room temperature to facilitate nucleation and crystal growth combined with the fast-heating rate in a tubular reactor at 363 K & 1.1 atm., which in turn produces LSX after 40 min. The synthesized product was confirmed by the XRD, FE-SEM, EDS, XRF, TEM, and N2 adsorption-desorption; the data was compared with the LSX sample synthesized by batch process. The result implies that LSX prepared by continuous flow has a pure phase of LSX with the hierarchical structure, which provides better adsorption capacity of CO2 at 298 K up to 20 bar. Due to continuous flow synthesis, the crystallization time was reduced and faster kinetics which may be helpful for scale-up the process for LSX synthesis.

10aAdsorption10aCarbon dioxide10acontinuous flow10aLow silica X10aTubular reactor10azeolites1 aAdarsh, V., K.1 aShrotri, Aadesh, R.1 aBirje, Amit, R.1 aNandanwar, Sachin, U. uhttps://library.ncl.res.in/content/continuous-flow-synthesis-hierarchical-low-silica-x-zeolite02167nas a2200265 4500008004100000022001400041245009100055210006900146260000900215300001200224490000800236520130800244653001501552653001901567653001301586653002701599653001501626100002401641700002001665700002801685700002201713700002101735700002601756856011901782 2024 eng d a1226-086X00aPerformance of Li exchange hierarchical X zeolite for CO2 adsorption and H2 separation0 aPerformance of Li exchange hierarchical X zeolite for CO2 adsorp cMAY  a505-5140 v1333 a

Li exchange hierarchical X zeolite (Li-H-X) was prepared by decationization of X zeolite by NH4Cl solution followed by Li exchange and subsequent calcination. NH4-X and Li-X were prepared to compare the results of LiH-X. XRD, FE-SEM, EDS, N2 adsorption-desorption, and micro-/mesoporous volume were performed. The higher mesoporosity was confirmed in Li-H-X due to the framework dealumination during decationization. Static and dynamic sorption capacity of sorbents was evaluated to identify the performance of sorbent. The CO2 and H2 equilibrium adsorption capacity of Li-H-X was found to be 9.6 mmol g-1 and 0.78 mmol g-1, respectively, at 298 K and 20 bar, which was 25 % (CO2) and 30 % (H2) higher than Li-X. Static experimental data were validated using the Langmuir, Freundlich, and Sips models. The CO2 & H2 dynamic sorption capacity of Li-H-X sorbent for binary gas (CO2/H2, 25/75 %) was 4.145 mmol g-1 and 0.258 mmol g-1 at 303 K and 10 bar. The higher sorption capacity of Li-H-X was obtained due to large micro-/mesoporous volume of sorbent, which may allow to access unoccupied sites at higher pressure. This result reveals that micro-/mesoporous structure of zeolite adsorbs significantly higher CO2 from binary gas stream, which can use to separate pure H2 from gas stream.

10aAdsorption10aCarbon dioxide10aHydrogen10aMicroporous-mesoporous10aSeparation1 aShrotri, Aadesh, R.1 aBirje, Amit, R.1 aNiphadkar, Prashant, S.1 aBokade, Vijay, V.1 aMali, Nilesh, A.1 aNandanwar, Sachin, U. uhttps://library.ncl.res.in/content/performance-li-exchange-hierarchical-x-zeolite-co2-adsorption-and-h2-separation02525nas a2200241 4500008004100000022001400041245010900055210006900164260000900233300001100242490000800253520173500261653001501996653002502011653002402036653001002060653001302070653000802083100002002091700002402111700002602135856012202161 2026 eng d a1387-181100aSynthesis of Core-Shell ETS-4@LSX zeolite composite to enhance CO2/N2 selectivity in flue gas separation0 aSynthesis of CoreShell ETS4LSX zeolite composite to enhance CO2N cJAN  a1138400 v3993 a

The selective removal of CO2 from the flue gas remains a quite challenging due to the weak selectivity of CO2/N2 in adsorbents. Therefore, it is necessary to design an effective sorbent to improve its selectivity. This work attempts to synthesis of novel core-shell ETS-4@LSX composite via a seed-assisted hydrothermal method. In this composite structure, a small pore titanosilcate ETS-4 as a core, while a large pore aluminosilicate LSX forms the outer shell. The effects of ETS-4 seed loading (1-5 wt.%) and crystallization time on the formation and structural integrity of the core-shell architecture was systematically investigated. The structural and physicochemical properties of samples were characterized by XRD, FE-SEM, HR-TEM, EDS, FT-IR, TGA, N2 adsorption-desorption, and pore size distribution. From XRD pattern and FE-SEM results confirmed that the composite synthesized with 2 wt% ETS-4 seed and 3 h crystallization time has pure phase of ETS-4@LSX structure. HR-TEM imaging revealed uniform growth of LSX over the ETS-4 surface, resulting in the formation of a continuous shell. The 2 wt% ETS4@LSX composite demonstrated an outstanding CO2/N2 equilibrium selectivity of 81.4 at 1 bar and 303 K with five and seven times higher than that of pure LSX and ETS-4, respectively. At 20 bar, the composite achieved a CO2 uptake of 5.25 mmol g- 1 and an N2 uptake of 0.50 mmol g- 1. Dynamic adsorption study exhibited the 2 wt% ETS-4@LSX has 3.52 mmol g- 1 CO2 sorption capacity and N2 uptake capacity of 0.26 mmol g- 1. The enhanced adsorption capacity and selectivity of ETS-4@LSX are attributed to its dual-pore structure, highlighting its potential as an effective adsorbent for CO2 capture from flue gas.

10aAdsorption10aCore-shell composite10aDual-pore structure10aETS-410aFlue gas10aLSX1 aBirje, Amit, R.1 aShrotri, Aadesh, R.1 aNandanwar, Sachin, U. uhttps://library.ncl.res.in/content/synthesis-core-shell-ets-4lsx-zeolite-composite-enhance-co2n2-selectivity-flue-gas