01923nas a2200241   4500008004100000022001400041245015200055210006900207260000900276300001400285490000700299520108500306653001301391653002501404653001301429653002401442653001401466100001901480700002801499700002301527700000501550856012601555       2020                        eng d  a2470-155600aSynthesis and characterization of supported heteropoly acid: efficient solid acid catalyst for glycerol esterification to produce biofuel additives0 aSynthesis and characterization of supported heteropoly acid effi  cNOV   a1157-11650 v503 a<p>Esterification of glycerol with acetic acid has been studied with different solid acid catalysts, prepared by impregnating phospotungustic, silicotungstic, and phosphomolybdic acids on polymeric material polyvinylpyrrolidone. These results were compared with commercially available montmorillonite KSFO catalyst showed that PVP-DTP gave higher selectivity to di- and triacetins. This study was mainly focused on increasing the selectivity toward triacetin which is an excellent alternative to fossil fuel based fuel additives. The detail characterization was done for the PVP-DTP catalyst which gave complete conversion of glycerol and maximum selectivity of 34% toward triacetin. Complete conversion of glycerol was achieved at 110 degrees C within 6 h of reaction time. The characterization of the catalyst was performed by SEM/EDX, X-ray diffraction, thermogravimetic techniques, and FT-IR analysis.TPD-NH3 characterization showed that DTP supported on PVP increases the catalyst acidity of PVP. The highest acidity of PVP-DTP is also confirmed using NH3-TPD analysis.</p>
10aGlycerol10aphospostugustic acid10apovidone10asolid acid catalyst10atriacetin1 aMagar, Subhash1 aMohanraj, Govindraj, T.1 aJana, Sumit, Kumar1 a  uhttps://library.ncl.res.in/content/synthesis-and-characterization-supported-heteropoly-acid-efficient-solid-acid-catalyst02339nas a2200277   4500008004100000022001400041245017000055210006900225260000800294300001600302490000700318520139900325653001401724653001901738653001901757653001501776653001701791653001301808653001301821100002301834700001901857700002301876700002201899700002901921856011101950       2023                        eng d  a2190-681500aEtherification of biomass-derived glycerol to oxygenated fuel additives using dodecatungstophosphoric-silica-supported catalyst: characterization and kinetic studies0 aEtherification of biomassderived glycerol to oxygenated fuel add  cNOV  a16285-162950 v133 a<p>
	Commercial biodiesel production is becoming popular due to its sustainability and reduced greenhouse gas emissions in comparison to fossil fuels. Biodiesel production involves the co-generation of crude glycerol that is not directly viable. Valorization of glycerol is essential from techno-economic perspective to achieve goals of circular economy. In this study, the glycerol etherification was carried out using tert-butyl alcohol in presence of dodecatungstophosphoric/silica (DTP/SiO2) catalyst for production of tert-butyl glycerol ethers that can be used as fuel additives. A series of DTP/SiO2 catalysts were prepared with various compositions by impregnating heteropoly acids (HPA, H3PW12O40). The product analysis was performed to monitor mono-, di-, and tri-tert-butyl glycerol ethers. The kinetic studies were conducted based on Langmuir-Hinshelwood model. The rate constants were determined from experimental data by regression analysis. The catalysts were characterized by X-ray diffraction, SEM/EDX, and thermogravimetric analysis. Varying DTP loadings resulted in different catalytic activities. Activation energy (38.23 kJ/mol), activation enthalpy (25.94 kJ/mol), activation entropy (-163.8 J/mol/K), and Gibbs free energy of activation (88.67 kJ/mol) were attained for DTP/SiO2 (20%) catalyst that exhibited the best selectivity for di-tert-butyl glycerol ethers.</p>
10aCatalytic10aetherification10afuel additives10aHinselwood10aImpregnation10akinetics10aLangmuir1 aMagar, Subhash, B.1 aKapoor, Ashish1 aJana, Sumit, Kumar1 aPal, Dan, Bahadur1 aRode, Chandrashekhar, V.  uhttps://library.ncl.res.in/content/etherification-biomass-derived-glycerol-oxygenated-fuel-additives-using