Faculty Publications
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Publications by NITK Faculty
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Item Liquid fuel from waste tires: novel refining, advanced characterization and utilization in engines with ethyl levulinate as an additive(Royal Society of Chemistry, 2021) Mohan, A.; Dutta, S.; Saravanan, S.; Madav, V.Pyrolysis is a promising thermochemical strategy to convert scrap tires into diesel-like fuels. Crude tire pyrolysis oil (CTPO) was produced in a 10 ton rotating autoclave reactor by thermal depolymerization of the tire polymers. In this work, the prior-reported straightforward and inexpensive strategy of upgrading CTPO using a combination of silica gel (as adsorbent) and petroleum ether (as the solvent) has been scaled up with minimal loss in mass of oil and improved physicochemical characteristics (e.g., lowered acid value, low sulfur content). The upgraded TPO (StTPO) was characterized extensively to better understand their chemical compositions, physicochemical properties, and combustion characteristics. StTPO was mixed with diesel in different volumetric proportions and the blends were studied for performance and emission characteristics in a single-cylinder engine. The use of biomass-derived ethyl levulinate (EL) as a fuel oxygenate improved the cold-flow properties of StTPO-diesel blends as well as lowered the exhaust emissions (e.g., lower NOx). A fuel blend consisting of 50% diesel, 40% StTPO, and 10% EL demonstrated the best fuel properties in the single-cylinder diesel engine. © The Royal Society of Chemistry 2021.Item Selective dehydration of 1-butanol to butenes over silica supported heteropolyacid catalysts: Mechanistic aspect(Elsevier B.V., 2021) Kella, T.; Vennathan, A.A.; Dutta, S.; Mal, S.; Shee, D.Butenes are considered as important olefinic building block to produce fuels/fuel additives and commodity chemicals. In the present investigation, selective dehydration of 1-butanol to butenes was studied in a continuous-flow fixed-bed reactor using various silica-supported heteropolyacid (HPA) catalysts such as phosphotungstic acid (PTA), silicotungstic acid (STA), phosphomolybdic acid (PMA), and silicomolybdic acid (SMA) as the solid acid catalysts. The physicochemical properties of these HPA were determined by BET, powder XRD, FTIR, NH3-TPD, and Py-FTIR. The acid strength and Brønsted/Lewis (B/L) acid ratio were increased with higher loading of HPA on silica. The nature of HPA (addenda and hetero atom) and loading of HPA are important factors for the dehydration of 1-butanol and selectivity towards butenes. PTA and STA showed superior catalytic activity than PMA and SMA. The reaction temperature and WHSV also strongly affected the butanol conversion and selectivity of butenes. The selectivity of di-n?butyl ether decreases with the rising temperature from 523 K to 623 K. The isomerization of 1-butene leading to the formation of other butene isomers depends on the HPA loading, temperature, and WHSV. The presence of molybdenum addendum atom in PMA and SMA promotes dehydrogenation and hydrogenation, leading to the formation of various light hydrocarbons. The 20PTA/SiO2 catalyst afforded 99.8% selectivity towards butenes at quantitative conversion of 1-butanol, whereas the 20STA/SiO2 catalyst gave nearly 97.0% conversion of 1-butanol and 99.9% butenes selectivity at 673 K, 37.4 h?1 of WHSV. © 2021Item Biomass-derived 5-(tolylmethyl)furfural as a promising diesel additive: preparation, process scale-up, and engine studies(Royal Society of Chemistry, 2025) Yadav, A.K.; Yadav, S.K.; Kumar, G.N.; Madav, V.; Dutta, S.Furanic fuel oxygenates, renewably produced from biomass, have received significant interest in lessening dependence on petroleum-derived liquid fuels and reducing emissions. 5-(Tolylmethyl)furfural (TMF) was prepared by the Friedel-Crafts reaction between cellulose-derived 5-(acetoxymethyl)furfural (AcMF) and petroleum-derived toluene. The process was optimized on various parameters, such as reaction temperature, molar ratio of reagents, catalyst loading, and duration. Anhydrous ZnCl2 was the best catalyst for the reaction, affording a 67% isolated yield of TMF under optimized conditions (120 °C, 4 h). TMF was prepared on a 30 g scale and blended (1-5 vol%) with diesel. The physicochemical properties of the TMF-diesel blended fuel mixtures were studied, and then they were employed as fuel for a direct injection single-cylinder diesel engine. The results show good fuel properties and reduced emissions compared to unblended diesel fuel. © 2025 The Royal Society of Chemistry.