@article {46755, title = {Maximization of furanic compounds formation by dehydration and hydrogenation of xylose in one step over SO3-H functionalized H-beta catalyst in alcohol media}, journal = {Biomass \& Bioenergy}, volume = {139}, year = {2020}, month = {AUG}, pages = {105646}, type = {Article}, abstract = {

Furanic compounds such as furfural (FUR); furfuryl alcohol (F. Alc) are important renewable platform chemicals can be used as such or further convert for preparation of other value added products such as Levulinic acid (LA), Alkyl Levulinates, 2-Methyltetrahydrofuran (MTHF), and Tetrahydrofuran (THF) etc. Sulfonated H-beta zeolite was successfully prepared and used for the synthesis of furanic compounds especially FUR and F. Alc from c-xylose in one step using isopropanol as alcohol media. Prepared catalyst was well characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), BET, NH3-Temperature programmed desorption (TPD) and carbon-hydrogen-nitrogen-sulfur analysis (CHNS). It was found the total acid amount was increased with increase in sulfur loading which confirmed the sulfonic acid group (SO3-H) was successfully grafted onto zeolite structure. 3 wt\% H-beta-SO3-H catalyst with optimized reaction parameters of 150 degrees C, 7 h, 25 wt\% catalyst loading was tuned to get the highest furanic compound yield of 88.5\% (FUR 76.8\% + F.Alc 11.7\%).The reusability study confirmed that there was a marginal drop of similar to 25\% after 3 recycle runs.

}, keywords = {furfural, Furfuryl alcohol, H-beta, isopropanol, sulfonated zeolite, Xylose}, issn = {0961-9534}, doi = {10.1016/j.biombioe.2020.105646}, author = {Gupta, Anshita and Nandanwar, Sachin U. and Niphadkar, Prashant and Simakova, Irina and Bokade, Vijay} } @article {46763, title = {Review of porous adsorbents for the separation of nitrogen from natural gas}, journal = {Industrial \& Engineering Chemistry Research}, volume = {59}, year = {2020}, month = {JUL}, pages = {13355-13369}, type = {Review}, abstract = {

Natural gas is one of the critical fossil fuel sources in the world to fulfill current energy demand in the global market. Methane is the primary component in natural gas and its concentration is dependent on the source; a variety of impurities, such as nitrogen, carbon dioxide, oxygen, helium, hydrogen sulfide, water, and heavier hydrocarbons can be present, which reduces the overall fuel quality. Purification of natural gas is important in order to meet the U.S. pipeline and minimum heating value specifications. The separation of nitrogen from methane is challenging because of their similar molecular size (i.e., the two gases differ in kinetic diameter by only 0.16 angstrom). This Review discusses different methods for separating nitrogen from methane. Of these methods, pressure swing adsorption is one of the most effective techniques for separating nitrogen from natural gas using porous adsorbents, and encouraging results have been demonstrated in the past few decades. Many types of porous adsorbents are discussed here, including carbon molecular sieves, activated carbons, zeolites, titanosilicates, and metal-organic frameworks. Future trends and materials are discussed to put into perspective the new opportunities in this research area.

}, issn = {0888-5885}, doi = {10.1021/acs.iecr.0c02730}, author = {Nandanwar, Sachin U. and Corbin, David R. and Shiflett, Mark B.} } @article {47585, title = {Active nickel hollow nanosphere supported over SiO2 catalyst for reduction of nitro compound}, journal = {Particulate Science and Technology}, volume = {40}, year = {2021}, month = {APR}, pages = {325-335}, type = {Article}, abstract = {

Nickel hollow nanospheres (Ni HNSs) was prepared by solvothermal method using mixture of ethylenediamine (EN) and ethanol (ET), sodium borohydride as reducing agent and nickel chloride hexahydrate as precursor. The particle size of the Ni HNSs were tuned by varying several parameters including precursor concentrations, reaction temperatures (130-190 degrees C), and ET to EN volume ratios. The particle size and morphology of Ni HNSs were confirmed by dynamic light scattering and transmission electron microscope, respectively. Spherical shape of Ni nanoparticles of 300 nm size having similar to 200 nm hollow space and 50 nm thickness was achieved at optimize condition of 4:6 volume ratio of ET/EN, 150 degrees C temperature, 0.1 M NaBH4 concentration, and 7 h. Ni HNSs supported over SiO2 (Ni HNSs/SiO2) with different loading of Ni HNSs (1-10 wt.\%) were prepared by impregnation method. The catalyst was characterized by X-ray diffraction, and inductively coupled plasma - optical emission spectroscopy. The catalytic performance of Ni HNSs/SiO2 was carried out in the reduction of 4-Nitrophenol (4-NP) to 4 - Aminophenol (4-AP). 5 wt.\% Ni HNSs/SiO2 exhibited 87\% reduction of 4-NP in 25 min and stable up to 6 catalyst cycles due to higher surface area of the catalyst.

}, keywords = {4-Aminophenol, 4-nitrophenol, Catalyst, hollow nanospheres, Nanoparticles, Nickel}, issn = {0272-6351}, doi = {10.1080/02726351.2021.1947424}, author = {Pawar, Priyanka S. and Lokhande, Aboli A. and Nandanwar, Sachin U. and Niphadkar, Prashant S. and Bokade, Vijay V.} } @article {46681, title = {Milder operating parameters for one-step conversion of fructose to levulinic acid over sulfonated H-beta zeolite in aqueous media}, journal = {Environmental Progress \& Sustainable Energy}, volume = {40}, year = {2021}, month = {JAN}, pages = {e13530}, type = {Article}, abstract = {

The sulfonated H-beta zeolite was successfully prepared and used for the synthesis of levulinic acid (LA) fromD-fructose. The catalyst was characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope, N-2 physisorption, NH3-temperature programmed desorption and carbon-hydrogen-nitrogen-sulfur analysis. The total acid amount is increased with increase in sulfur loading, confirmed that the sulfonic acid group (SO3-H) is successfully grafted onto zeolite structure. The various parameters such as different amount of sulfur loading, reaction temperature, time, catalyst loading was studied for selective production of LA. The catalytic activity of sulfonated H-beta (S-beta) zeolite was found to be efficient for synthesis of LA from D-fructose in aqueous media. Maximum LA yield of 43.5 mol\%, low HMF yield (\<1\%) with 98.15\% fructose conversion was obtained with 3\% S-beta catalyst at 160 degrees C for 7 hr. The catalyst was reusable for minimum three times by H2O2 regeneration. This study provides the new zeolitic catalyst for the efficient production of LA at shorter reaction time (7 hr) and low catalyst to substrate ratio (0.7:1).

}, keywords = {conversion, D-fructose, H-beta, HMF, levulinic acid, sulfonated zeolite, yield}, issn = {1944-7442}, doi = {10.1002/ep.13530, Early Access Date = OCT 2020}, author = {Bisen, Swapneel K. and Niphadkar, Prashant S. and Nandanwar, Sachin U. and Simakova, Irina and Bokade, Vijay V.} } @article {47811, title = {Milder operating parameters for one-step conversion of fructose to levulinic acid over sulfonated H-β zeolite in aqueous media}, journal = {Environmental Progress \& Sustainable Energy}, volume = {40}, year = {2021}, month = {FEB}, pages = {e13530}, type = {Article}, abstract = {Abstract The sulfonated H-β zeolite was successfully prepared and used for the synthesis of levulinic acid (LA) from D-fructose. The catalyst was characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope, N2 physisorption, NH3-temperature programmed desorption and carbon{\textendash}hydrogen{\textendash}nitrogen{\textendash}sulfur analysis. The total acid amount is increased with increase in sulfur loading, confirmed that the sulfonic acid group (SO3-H) is successfully grafted onto zeolite structure. The various parameters such as different amount of sulfur loading, reaction temperature, time, catalyst loading was studied for selective production of LA. The catalytic activity of sulfonated H-β (S-β) zeolite was found to be efficient for synthesis of LA from D-fructose in aqueous media. Maximum LA yield of 43.5 mol\%, low HMF yield (<1\%) with 98.15\% fructose conversion was obtained with 3\% S-β catalyst at 160{\textdegree}C for 7 hr. The catalyst was reusable for minimum three times by H2O2 regeneration. This study provides the new zeolitic catalyst for the efficient production of LA at shorter reaction time (7 hr) and low catalyst to substrate ratio (0.7:1).}, keywords = {conversion, D-fructose, H-β, HMF, levulinic acid, sulfonated zeolite, yield}, doi = {10.1002/ep.13530}, url = {https://aiche.onlinelibrary.wiley.com/doi/abs/10.1002/ep.13530}, author = {Bisen, Swapneel K. and Niphadkar, Prashant S. and Nandanwar, Sachin U. and Simakova, Irina and Bokade, Vijay V.} } @article {47129, title = {Review on selective production of acetophenone from oxidation of ethylbenzene over heterogeneous catalysts in a decade}, journal = {Catalysis Letters}, year = {2021}, month = {JAN}, type = {Article; Early Access 2021}, abstract = {

The consumption of acetophenone (AP) is increasing worldwide because of its applications in products such as alcohol, aldehydes, resins, esters, fragrances, and pharmaceuticals. AP is manufactured via several methods like decomposition of cumene hydroperoxide, Hock process, and Friedel-Crafts acylation reaction using homogeneous catalysts with solvent and oxidant. However, it causes several environmental problems that deteriorate the production of AP with these methods. Oxidation of ethylbenzene (EB) is one of the promising methods to synthesize AP in liquid and vapor phases reaction using heterogeneous catalysts, which plays a vital role for selective production of AP. In this review, numerous heterogeneous catalysts are discussed including transition metal nanoparticles, transition metal complexes, and metal free catalysts (carbon nanotubes) used in last 10 years for oxidation of EB. Additionally, catalyst activity along with reaction parameters and its effect, mechanisms, and kinetics study are summarized in this article. The future scope of this reaction is also highlighted. Moreover, this work identifies best catalysts for bulk production of AP with high yield to satisfy global requirement.

}, keywords = {acetophenone, ethylbenzene, Heterogeneous catalysts, Oxidation reaction, reaction mechanisms}, issn = {1011-372X}, doi = {10.1007/s10562-020-03474-8, Early Access Date = JAN 2021}, author = {Nandanwar, Sachin U. and Rathod, Simmy and Bansal, Videsha and Bokade, Vijay V.} } @article {47895, title = {Catalytic activity of CuFe2O4 spinel oxide for liquid-phase oxidation of cinnamyl alcohol}, journal = {ChemistrySelect}, volume = {7}, year = {2022}, month = {FEB}, pages = {e202104441}, type = {Article}, abstract = {

CuFe2O4 spinel oxide catalyst was synthesized by sol-gel and co-precipitation methods for liquid phase oxidation of Cinnamyl alcohol (CnOH) to Cinnamaldehydes (CnHO) using tert-Butyl hydroperoxide (TBHP) as oxidising agent. Spinel oxide catalyst was characterized by different techniques such as X-ray diffraction (XRD), N-2 adsorption-desorption, BET surface area, and X-ray photoelectron spectroscopy (XPS) to understand the structural, physical properties and oxidation state of the catalyst. The result shows that catalyst prepared by sol-gel method was found higher surface area and smaller crystalline size than co-precipitation method. XPS data confirm the formation of Cu2+ in the spinel which helps to improve the catalytic activity of oxidation. This reaction follows radical mechanism, and exhibited 76.7 \% of CnOH conversion and 68.4 \% of CnHO, and 24.8 \% benzaldehyde (benzald) selectivity using TBHP at 60 degrees C. Kinetic data reveal that 41.2 kJ/mol of activation energy for the reaction. The higher activity of spinel oxide catalyst could be due synergetic effect of spinel (88 \%) and oxides (12 \%) formed in the catalyst, which helps to provide the oxygen during reaction. The contribution of Cu2+ is higher in sol-gel than co-precipitation, which may provide the better reactivity of catalyst. This work helps to select the effective and cost-effective catalyst for the oxidation of CnOH.

}, keywords = {Catalysts, Cinnamaldehyde, Cinnamyl Alcohol, Cupper, iron, oxide, spinel}, issn = {2365-6549}, doi = {10.1002/slct.202104441}, author = {Dange, Rutvija M. and Niphadkar, Prashant S. and Bokade, Vijay V. and Nandanwar, Sachin U.} } @article {47984, title = {Methanol-to-light olefins reaction using Zn-Ag modified SSZ-13 catalyst}, journal = {ChemistrySelect}, volume = {7}, year = {2022}, month = {SEP}, pages = {e202201476}, type = {Article}, abstract = {

The 2 wt.\% of Zn and Ag (Zn1-x-Ag-x; x=0.2, 0.4, 0.6 \%) modified SSZ-13 (SZ-13) zeolite was prepared by wet-impregnation method, and its catalytic activity was demonstrated for methanol-to-olefin (MTO). The Zn-0.6-Ag-0.4/SZ-13 catalyst exhibited high catalytic activity due to change in properties of catalyst. The Zn particles were highly dispersed inside the SZ-13; while Ag particles were dispersed on the surface of SZ-13, confirmed by HRTEM and surface area. The small \% of Ag over SZ-13 promotes ethylene production via aromatization of reaction, and highly dispersed Zn on SZ-13 help to produce stable ethylene and propylene. The Zn-0.6-Ag-0.4/SZ-13 catalyst showed (similar to 10 \%) higher light olefin (87 \%) selectivity than parent SZ-13 as well as mono metal incorporated SZ-13. The higher catalytic activity was attributed due to effect of both metals (Zn and Ag), where Ag promotes partial aromatization on the surface, and Zn increases the Lewis acidity in the zeolite pore. This catalyst can help to improve the selectivity of light olefin using MTO reaction.

}, keywords = {Ethylene, Methanol-to-Olef, Propyl, Silver, SSZ, zinc}, issn = {2365-6549}, doi = {10.1002/slct.202201476}, author = {Dange, Rutvija M. and Gawali, Chirag B. and Niphadkar, Prashant S. and Bokade, Vijay V. and Nandanwar, Sachin U.} } @article {48702, title = {Equilibrium adsorption of nitrogen, oxygen, and argon on silver-exchanged hierarchical ETS-10}, journal = {Journal of Chemical and Engineering Data}, volume = {68}, year = {2023}, month = {JUL}, pages = {2159-2172}, type = {Article}, abstract = {

Silver-exchanged hierarchical ETS-10(Ag-H-ETS-10) was synthesizedusing Ag+ exchange with hierarchical Engelhard titanosilicate(H-ETS-10) using silver nitrate solution. The physical propertiesof the adsorbent were analyzed using X-ray diffraction (XRD), BETsurface area, nitrogen adsorption-desorption, pore volume,energy dispersive spectroscopy (EDS), and high resolution-transmissionelectron microscopy (HR-TEM). N-2 physisorption data confirmedthat a micro-mesoporous (bimodal) structure was created in the Ag-H-ETS-10.The equilibrium adsorbent data of pure gases N-2, O-2, and Ar were investigated in the temperature range from 288to 318 K up to 10 bar. The equilibrium adsorption capacity of Ag-H-ETS-10was found to be 1.12 mmol g(-1) for N-2,0.87 mmol g(-1) for O-2, and 1.09 mmol g(-1) for Ar at 298 K and \& SIM;10 bar. \& SIM;20\% higheradsorption capacity was found for N-2 and Ar in Ag-H-ETS-10compared to Ag-ETS-10. The higher sorption capacity was attributedto the formation of a bimodal structure and \& pi;-complexation interactionby the Ag cation, which allows a multilayer of N-2 and Armolecules. The Sips isotherm model was well fitted for the Ag-H-ETS-10experimental data among Langmuir, Freundlich, Toth, and Temkin models.The measured equilibrium adsorption data for Ag-H-ETS-10 can be usefulfor the O-2 purification process.

}, issn = {0021-9568}, doi = {10.1021/acs.jced.3c00124}, author = {Shrotri, Aadesh R. and Niphadkar, Prashant S. and Bokade, Vijay V. and Nandanwar, Sachin U.} } @article {49295, title = {Continuous flow synthesis of hierarchical low silica X zeolite}, journal = {Materials Today Communications}, volume = {39}, year = {2024}, month = {JUN}, pages = {109047}, type = {Article}, abstract = {

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.

}, keywords = {Adsorption, Carbon dioxide, continuous flow, Low silica X, Tubular reactor, zeolites}, doi = {10.1016/j.mtcomm.2024.109047}, author = {Adarsh, V. K. and Shrotri, Aadesh R. and Birje, Amit R. and Nandanwar, Sachin U.} } @article {48905, title = {Effect of CTMABr/SiO2 molar ratio in synthesis of micro-mesoporous ZSM-5 composite and its application in 5-EMF (biofuel additive) formation}, journal = {Environmental Progress and Sustainable Energy }, volume = {43}, year = {2024}, month = {JAN}, type = {Article}, abstract = {

Synthesis of micro-mesoporous zeolite composite with optimum micro and mesoporosity is an emerging research area due to its wide applications, especially in bulk chemical or biomass transformations. It offers advantages in preserving zeolite crystallinity, creating mesoporosity and converting bulky molecules into valuable products. This work presents the process of preparing bimodal micro-mesoporous ZSM-5 using dual templates (CTMABr and TPABr). XRD, N2 adsorption-desorption, SEM, TEM, Si-29, and Al-27 NMR were used to analyze the two-dimensional micro-mesoporous ZSM-5. One-step synthesis of bimodal micro-mesoporous ZSM-5 features dual micro/mesoporosity by a marginal decrease in the crystallinity (71\%). Micro-mesoporous ZSM-5 composite was found to be dependent on the optimum CTMABr/SiO2 molar ratio of 0.04 to 0.06. The micro-mesoporous ZSM-5 zeolite composite was evaluated for cascade synthesis of 5-EMF (methoxymethyl furfural- biofuel additive) from fructose and exhibited a five fold increase in 5-EMF yield to 24.2\% as compared with parent ZSM-5 (4.6\%).

}, keywords = {fructose, methoxymethyl furfural-biofuel additive, micro-meso composite, ZSM-5}, issn = {1944-7442}, doi = {10.1002/ep.14258}, author = {Manal, Prajakta N. and Niphadkar, Prashant S. and Nandanwar, Sachin U. and Bokade, Vijay V.} } @article {49022, title = {Performance of Li exchange hierarchical X zeolite for CO2 adsorption and H2 separation}, journal = {Journal of Industrial and Engineering Chemistry }, volume = {133}, year = {2024}, month = {MAY }, pages = {505-514}, type = {Article}, abstract = {

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.

}, keywords = {Adsorption, Carbon dioxide, Hydrogen, Microporous-mesoporous, Separation}, issn = {1226-086X}, doi = {10.1016/j.jiec.2023.12.027}, author = {Shrotri, Aadesh R. and Birje, Amit R. and Niphadkar, Prashant S. and V. Bokade, Vijay and Mali, Nilesh A. and Nandanwar, Sachin U.} } @article {49254, title = {Pressure swing adsorption of Li exchange hierarchical X zeolite for pure hydrogen from binary gas mixture}, journal = {International Journal of Hydrogen Energy}, volume = {73}, year = {2024}, month = {JUL }, pages = {138-147}, type = {Article}, abstract = {

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.

}, keywords = {adsorbent, Binary gas mixture, Hydrogen purification, Li-H-X, Mesoporous zeolite, Pressure swing adsorption}, issn = {0360-3199}, doi = {10.1016/j.ijhydene.2024.06.011}, author = {Shrotri, Aadesh R. and Birje, Amit R. and Nandanwar, Sachin U.} } @article {49769, title = {Binderless low silica X zeolite for methane separation from binary CO2/CH4 biogas stream: A comprehensive experimental and computational study}, journal = {Journal of Industrial and Engineering Chemistry}, volume = {149}, year = {2025}, month = {SEP }, pages = {705-719}, type = {Article}, abstract = {

This study presents the synthesis of binderless Na-LSX (B-Na-LSX) and binderless NaK-LSX (B-NaK-LSX). XRD, SEM, EDS, and N-2 physisorption were used for characterization of samples. Computational modelling of prepared sorbent was performed for the fundamental understanding of zeolite topology and adsorption behaviour. The breakthrough experiments are used to evaluate the adsorption capacities on CO2/CH4 (40/60 vol\%) binary biogas stream. The results were compared with commercial Na-LSX (C-Na-LSX). The breakthrough adsorption capacity of B-Na-LSX was 3.08 mmol g(-1) and 0.29 mmol g(-1) of CO2 and CH4, respectively, at 300 K and 1 bar. CO2 sorption capacity of B-Na-LSX was similar to 11 \% and similar to 17 \% higher than B-NaK-LSX (2.77 mmol g(-1)) and C-Na-LSX (2.56 mmol g(-1)), respectively. DFT study reveals that the higher adsorption of CO2 over CH4 was attributed to higher charge transfer from CO2 to zeolite framework. Dual-bed six-step Pressure Swing Adsorption (PSA) was performed on B-Na-LSX at 6 bar. similar to 232 cycles were run with above 98 \% of CH4 purity and similar to 74 \% of recovery. The life-cycle test of sorbent was studied. It was implied that the designed sorbent is effective to produce the high purity of CH4 and can be utilized for a longer period for CH4 production.

}, keywords = {Binderless, Biogas, LSX zeolite, methane, PSA, Separation}, issn = {1226-086X}, doi = {10.1016/j.jiec.2025.02.031}, author = {Yadav, Tushar R. and Shrotri, Aadesh R. and Kate, Pranjali N. and Devasia, George and Niphadkar, Prashant S. and Mali, Nilesh A. and Krishnamurty, Sailaja and Bokade, Vijay V. and Nandanwar, Sachin U.} } @article {49491, title = {Evaluating the preferential adsorption of N2 from a binary mixture of N2/O2 on extra-framework cations of zeolites: a computational and experimental study}, journal = {Physical Chemistry Chemical Physics}, volume = {27}, year = {2025}, month = {APR }, pages = {7846-7857}, type = {Article}, abstract = {

Separation of N2 from a N2/O2 gas mixture is critical for various industrial/medical applications. Temperature/pressure swing adsorption is the top-notch industrial technology used for this separation, where zeolites are the materials used for adsorption. Zeolite X/Y with Li+ as an extra-framework cation is the best-known sorbent for N2 gas molecules. However, the present net zero emission scenario has made lithium a critical element, making it imperative to implement its alternative in various other technologies. In this context, the present work is a computational evaluation to identify a cation that can replace Li+ for preferential adsorption of N2 over O2. The DFT study, based on parameters such as selective adsorption energies of N2 over O2 and IR stretching frequencies of the adsorbed N2 and O2 molecules, identifies Mg2+, Ca2+, Sr2+, Co2+ and Zn2+ as potential cations. These cations have preferential adsorption for N2 over O2 by 10 kJ mol-1 or more. However, BOMD simulations reveal that only Mg2+, Ca2+, Co2+ and Zn2+ keep the N2 molecule bound at 300 K and the O2 molecule gets desorbed from these frameworks. The desorption temperature of N2 on Ca2+ and Zn2+ is 350 K and on Mg2+ is 400 K. These observations are corroborated by electronic charges on cations and molecular orbitals. Significantly, Ca2+ is identified to adsorb up to 2 N2 molecules, making it an ideal candidate for N2/O2 separation in place of Li+. To validate this, we have carried out an experimental study that showed a good N2 adsorption capacity of 2.1 mmol g-1 for Ca2+.

}, issn = {1463-9076}, doi = {10.1039/d4cp04193c}, author = {Devasia, George and Nandanwar, Sachin U. and Krishnamurty, Sailaja} } @article {49529, title = {Optimizing H2/CO2 binary gas mixture separation using Li-K-ETS-10 zeolite: Breakthrough analysis and impact of operational conditions}, journal = {International Journal of Hydrogen Energy}, volume = {105}, year = {2025}, month = {MAR}, pages = {673-683}, type = {Article}, abstract = {

The polycation-exchanged ETS-10 (Li-K-ETS-10) zeolite was employed as a sorbent in breakthrough experiments using a binary H2/CO2 (75/25\%) gas mixture. The data compared with parent adsorbent (NaK)-ETS-10, and mono cation exchange of ETS-10 (K-ETS-10 and Li-ETS-10). Adsorbents underwent for various characterization including XRD, Raman, FTIR, EDS, CO2-TPD, BET surface area, and pore diameter of samples to understand the physicochemical properties. CO2-TPD shows that Li-K-ETS-10 has higher basicity than parent (NaK)-ETS-10. The process parameters were optimized to ensure a higher CO2 sorption capacity and better H2 purity including effects of flow rate, pressure, temperature, feed concentration, bed height, and recyclability. The adsorption capacities of CO2 and H2 were found to be 1.57 mmol g- 1 and 0.24 mmol g-1, respectively, at 1 bar and a flow rate of 200 mL min- 1. These values represent a 40\% improvement over (NaK)-ETS-10 and a-10.4\% improvement over Li-ETS-10. At 6 bar, the CO2 and H2 adsorption capacities reached 2.79 mmol g- 1 and 0.22 mmol g-1, respectively. The higher CO2 sorption over Li-K-ETS-10 leads due to improve in basic sites and physical properties of sample compare to studied adsorbent. The experimental data of binary gas mixture was used to evaluate the kinetic models including Thomas, and Yoon-Nelson. This results implies that Li-K-ETS-10 is the promising candidates for H2 separation from binary gas mixture.

}, keywords = {adsorbent, Binary gas stream, Breakthrough study, H2/CO2 separation, Kinetic modelling, Li-K-ETS-10}, issn = {0360-3199}, doi = {10.1016/j.ijhydene.2025.01.324}, author = {Shrotri, Aadesh R. and Nandanwar, Sachin U.} } @article {49811, title = {Synthesis of Core-Shell ETS-4@LSX zeolite composite to enhance CO2/N2 selectivity in flue gas separation}, journal = {Microporous and Mesoporous Materials}, volume = {399}, year = {2026}, month = {JAN }, pages = {113840}, type = {Article}, abstract = {

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.

}, keywords = {Adsorption, Core-shell composite, Dual-pore structure, ETS-4, Flue gas, LSX}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2025.113840}, author = {Birje, Amit R. and Shrotri, Aadesh R. and Nandanwar, Sachin U.} }