02167nas 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<p>
	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 &amp; 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.</p>
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-separation02375nas a2200241   4500008004100000022001400041245011000055210006900165260000900234300001200243490000700255520154900262653001401811653002301825653002601848653001101874653002301885653003001908100002401938700002001962700002601982856012502008       2024                        eng d  a0360-319900aPressure swing adsorption of Li exchange hierarchical X zeolite for pure hydrogen from binary gas mixture0 aPressure swing adsorption of Li exchange hierarchical X zeolite   cJUL   a138-1470 v733 a<p>
	This study reports the separation of pure hydrogen (H2) employing pressure swing adsorption (PSA). The Li-X and Li-hierarchical X (Li-H-X) zeolite were prepared by an ion exchange process. The sorbents were evaluated through several experiments including, breakthrough, empty bed contact time (EBCT), single-bed, and two-bed PSA with different steps. The effect of pressure, purity, and recovery relationship was developed. The highpressure PSA study was performed at 4, 6, and 10 bar with varying feed flow rates to assess their efficacy in pure H2 separation using binary gas stream (H2/CO2, 75/25 vol.%). The breakthrough adsorption capacity of Li-H-X exhibited 3.4 mmol g-1 and 0.212 mmol g-1 of CO2 and H2, respectively. Li-H-X shows -8% higher CO2 sorption capacity than the Li-X sorbent at 1 bar and 300 K due to the large meso-microporous structure of the sorbent. The two-bed PSA purity and recovery were found higher than single-bed PSA. Using two-bed PSA, the Li-H-X achieved a 99.5% of purity, 92.9% of recovery, and 10.4 mL min-1 g-1 of productivity, which was -16% higher recovery and productivity than single-bed PSA at a flow rate of 1200 mL min-1 at 6 bar. With increasing the pressure and flow rate, the recovery of Li-H-X was enhanced up to 93.7% with 99.1%-99.9% H2 purity. The long-term PSA was run using Li-H-X sorbent for 7.5 h with 230 cycles with H2 purity between 98.5 and 99.5% at 6 bar. Interestingly, the adsorbent shows the scalability of PSA for efficient H2 separation for a binary mixture of H2/CO2.</p>
10aadsorbent10aBinary gas mixture10aHydrogen purification10aLi-H-X10aMesoporous zeolite10aPressure swing adsorption1 aShrotri, Aadesh, R.1 aBirje, Amit, R.1 aNandanwar, Sachin, U.  uhttps://library.ncl.res.in/content/pressure-swing-adsorption-li-exchange-hierarchical-x-zeolite-pure-hydrogen-binary-gas