@article { ISI:000320976600013, title = {Catalytic upgrading of renewable levulinic acid to ethyl levulinate biodiesel using dodecatungstophosphoric acid supported on desilicated H-ZSM-5 as catalyst}, journal = {Applied Catalysis A-General}, volume = {460}, year = {2013}, month = {JUN}, pages = {90-98}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Levulinic acid (LA) is considered as a renewable platform chemical and can be used for the synthesis of variety of important fuels and chemicals. In particular, its esterification with ethanol produces ethyl levulinate (EL) would be green process, as it can be used as diesel miscible biofuel (DMB), preventing global warming by decreasing atmospheric CO2. This study explores the use of modified H-ZSM-5 by desilication viz.; DH-ZSM-5 and dodecatungstophosphoric acid (DTPA) loaded on DH-ZSM-5 for esterification of LA with ethanol aiming to EL. Different degree of desilication of H-ZSM-5 was performed by using aq. NaOH (0.2-1.5 M) at 338 K for 30 min and then DTPA was loaded on these desilicated H-ZSM-5 (DH-ZSM-5) support. H-ZSM-5, DH-ZSM-5 and DTPA on these DH-ZSM-5 samples were characterized by powder x-ray diffraction (XRD), N-2 adsorption-desorption, pyridine chemisorbed IR spectroscopy, Temperature Programmed Ammonia Desorption (TPAD). The increase in conversion of levulinic acid was observed from 28\% to 94\% with increase of DTPA loading from 0\% to 15\%. The increased LA conversion may be due to increase in total acidity from 43.14\% to 84.31\%. The use of DH-ZSM-5 as support for deposition of DTPA may be reported for the first time. The present work also extended to optimize process parameters such as DTPA loading on DH-ZSM-5, catalyst to LA ratio, LA to ethanol molar ratio, speed of agitation, particle size reaction temperature and catalyst reusability. Kinetic study based on pseudo-homogeneous (P-H) model is also presented. The experimental results follow second order kinetics. (C) 2013 Elsevier B.V. All rights reserved.

}, keywords = {desilicated H-ZSM-5, DTPA on desilicated H-ZSM-5, Esterification, ethyl levulinate, levulinic acid}, issn = {0926-860X}, doi = {10.1016/j.apcata.2013.04.024}, author = {Nandiwale, Kakasaheb Y. and Sonar, Shilpa K. and Niphadkar, Prashant S. and Joshi, Praphulla N. and Deshpande, Shilpa S. and Patil, Vilas S. and Bokade, Vijay V.} } @article { ISI:000341764500007, title = {Esterification of renewable levulinic acid to ethyl levulinate biodiesel catalyzed by highly active and reusable desilicated H-ZSM-5}, journal = {Journal of Chemical Technology and Biotechnology}, volume = {89}, number = {10}, year = {2014}, month = {OCT}, pages = {1507-1515}, publisher = {WILEY-BLACKWELL}, type = {Article}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

BACKGROUNDIn the near future, fossil fuel will have limitations in terms of availability and also great concerns over its environmental impact. New routes and related technologies based on renewable feedstocks can overcome most of these problems associated with fossil fuel. Among current biodiesel sources, ethyl levulinate (EL) biodiesel obtained from catalytic esterification of renewable levulinic acid (LA) with ethanol has received a great deal of attention. The use of desilicated H-ZSM-5 (DH-ZSM-5) as heterogeneous acid catalyst for EL biodiesel production in a closed system (under autogeneous pressure) was studied. RESULTSThe effect of reaction parameters such as ethanol to LA molar ratio (4:1 to 10:1), catalyst to LA ratio (0.10-0.25), speed of agitation (100-400rpm), particle size (53-355 mu m), reaction temperature (363-403K) and reaction time (7h) was investigated to maximize LA conversion. CONCLUSIONLevulinic acid conversion reached 95\% over DH-ZSM-5 and the catalyst was reusable for up to six cycles. This LA conversion and the catalyst reusability values are higher than others reported in the literature. A pseudo-homogeneous (P-H) kinetic model indicated that reaction rate constants increased with increasing molar ratio, catalyst to LA ratio and reaction temperature. The activation energy decreased from 73.14 to 21.08 kJ mol(-1) when increasing the catalyst to LA ratio from 0.10 to 0.25, which implies a kinetically controlled reaction. (c) 2013 Society of Chemical Industry

}, keywords = {desilicated H-ZSM-5, Esterification, ethyl levulinate, levulinic acid}, issn = {0268-2575}, doi = {10.1002/jctb.4228}, author = {Nandiwale, Kakasaheb Y. and Niphadkar, Prashant S. and Deshpande, Shilpa S. and Bokade, Vijay V.} } @article { ISI:000340350900018, title = {Production of octyl levulinate biolubricant over modified H-ZSM-5: Optimization by response surface methodology}, journal = {Journal of Energy Chemistry}, volume = {23}, number = {4}, year = {2014}, month = {JUL}, pages = {535-541}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The present study highlighted the use of modified H-ZSM-5 (Meso-HZ-5) as heterogeneous catalyst for the synthesis of octyl levulinate biolubricant by catalytic esterification of biomass derived renewable levulinic acid (LA) with n-octanol. The process variables such as catalyst loading (X-1), n-octanol to LA molar ratio (X-2) and reaction temperature (X-3) were optimized through response surface methodology (RSM), using Box-Behnken model. Analysis of variance was performed to determine the adequacy and significance of the quadratic model. The yield of octyl levulinate was obtained to be 99\% at optimum process parameters. The developed quadratic model was found to be adequate and statistically accurate with correlation value (R-2) of 0.9971 to predict the yield of octyl levulinate biolubricant. The study was also extended on the validation of theoretical and experimental data, including catalyst reusability.

}, keywords = {biolubricant, Esterification, H-ZSM-5, levulinic acid, octyl levulinate, Response surface methodology}, issn = {2095-4956}, doi = {10.1016/S2095-4956(14)60182-0}, author = {Nandiwale, Kakasaheb Y. and Yadava, Sunil K. and Bokade, Vijay V.} } @article { ISI:000329791800007, title = {Pseudo-homogeneous kinetic model for esterification of acetic acid with propanol isomers over dodecatungstophosphoric acid supported on montmorillonite k10}, journal = {Journal of Physical Organic Chemistry}, volume = {27}, number = {2}, year = {2014}, month = {FEB}, pages = {121-127}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

Esterification of acetic acid with propanol isomers such as isopropanol and naEuropropanol was carried out over dodecatungstophosphoric acid (DTPA), dodecamolybdophosphoric acid ammonium salt hydrate, and sodium tungstate hydrated purified supported on montmorillonite K10, which were characterized by powder XaEuroray diffraction, BrunaueraEuro{\textquoteright}EmmettaEuro{\textquoteright}Teller, and temperature programmed ammonia desorption. A pseudoaEurohomogeneous (PaEuroH) kinetic model was established for esterification of acetic acid with propanol isomers over DTPA supported on montmorillonite K10. Effects of various parameters such as reaction time, speed of agitation, particle size, temperature, percent catalyst loading, molar ratio and mixture of propanol isomer were investigated in detail. The 20\% (w/w) DTPA/K10 was found to be an optimum solid catalyst with 82\% naEuropropanol and 53\% isopropanol conversion with 100\% selectivity toward propyl acetate. The 20\% (w/w) DTPA/K10 catalyst was found to be reusable for three cycles. The reaction follows secondaEuroorder kinetics with activation energies of 25.53aEuro?kJaEuro?mol(a?{\textquoteright}1) and 28.15aEuro?kJaEuro?mol(a?{\textquoteright}1) for isopropanol and naEuropropanol, respectively. PseudoaEurohomogeneous kinetic model fitted with R-2 value of trend line 0.999. This implies that esterification reaction is kinetically controlled owing to high activation energy. Copyright a (c) 2013 John Wiley \& Sons, Ltd.

}, keywords = {Acetic acid, dodecatungstophosphoric acid, Esterification, kinetic model, montmorillonite K10}, issn = {0894-3230}, doi = {10.1002/poc.3249}, author = {Gurav, Hanumant R. and Nandiwale, Kakasaheb Y. and Bokade, Vijay V.} } @article { ISI:000355231200019, title = {Environmentally benign catalytic process for esterification of renewable levulinic acid to various alkyl levulinates biodiesel}, journal = {Environmental Progress \& Sustainable Energy}, volume = {34}, number = {3}, year = {2015}, month = {SEP}, pages = {795-801}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

This study explores, the use of modified zeolite (Micro/Meso-HZ-5) obtained by desilication post-treatment as heterogeneous catalyst for esterification of biomass derived renewable levulinic acid (LA) with different alkyl alcohols such as methanol, ethanol, n-butanol, and n-octanol aiming to produce corresponding alkyl levulinate. This method of production of alkyl levulinates would be sustainable process, as it can be used as novel miscible diesel biofuels preventing global warming by decreasing atmospheric CO2. The LA conversion obtained over Micro/Meso-HZ-5 was higher than H-ZSM-5, which is due to the combined effect of increase in Bronsted acid sites, total acidity, and other properties such as BET surface area and the generation of mesoporosity. The maximum LA conversion of 91, 95, 96, and 98\% with 100\% selectivity toward alkyl levulinate was obtained, when LA was being esterified over Micro/Meso-HZ-5 with methanol, ethanol, n-butanol, and n-octanol, respectively, at optimal process parameters. Micro/Meso-HZ-5 catalyst was found to be reusable for six cycles. Furthermore, pseudo homogeneous (P-H) kinetic model of the esterification of LA with the studied four alcohols were established with R-2\>0.99, using the experimental data. A P-H kinetic model implies that, the esterification reaction follows second order reversible kinetics. (c) 2014 American Institute of Chemical Engineers Environ Prog, 34: 795-801, 2015

}, keywords = {biofuels, Esterification, kinetic model, levulinic acid, meso-HZ-5, micro}, issn = {1944-7442}, doi = {10.1002/ep.12042}, author = {Nandiwale, Kakasaheb Y. and Bokade, Vijay V.} } @article { ISI:000348924600005, title = {Esterification of renewable levulinic acid to n-butyl levulinate over modified H-ZSM-5}, journal = {Chemical Engineering \& Technology}, volume = {38}, number = {2}, year = {2015}, month = {FEB}, pages = {246-252}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The synthesis of n-butyl levulinate, one of the most important biodiesel additives, by catalytic esterification of biomass-derived levulinic acid (LA) with n-butanol over modified H-ZSM-5 (micro/meso-HZ-5) in a closed-batch system is reported for the first time. The optimization of the reaction conditions such as the reactant molar ratio, the catalyst loading, the reaction time and the temperature was performed in view to maximize the yield of n-butyl levulinate. Micro/meso-HZ-5 was found to be the most efficient catalyst, with 98\% yield of n-butyl levulinate and a reusability for six cycles, which is higher than reported in the literature. A possible catalytic mechanism for the esterification reaction is also proposed. A second-order pseudo-homogeneous model with R-2 \> 0.97 confirmed that the esterification reaction is performed in the kinetic regime due to the high activation energy of 23.84 kJ mol(-1).

}, keywords = {Esterification, kinetic model, levulinic acid, Micro/meso-HZ-5, n-Butyl levulinate}, issn = {0930-7516}, doi = {10.1002/ceat.201400326}, author = {Nandiwale, Kakasaheb Y. and Bokade, Vijay V.} } @article { ISI:000370104700016, title = {Optimization by box-behnken experimental design fur synthesis of n-hexyl levulinate biolubricant over hierarchical H-ZSM-5: an effort towards agricultural waste minimization}, journal = {Process Safety and Environmental Protection}, volume = {99}, year = {2016}, month = {JAN}, pages = {159-166}, publisher = {INST CHEMICAL ENGINEERS}, type = {Article}, address = {165-189 RAILWAY TERRACE, DAVIS BLDG, RUGBY CV21 3HQ, ENGLAND}, abstract = {

The present study is devoted to develop efficient catalytic process for conversion of agricultural waste feedstock to value added chemicals. In this context, the n-hexyl levulinate, a renewable biolubricant was synthesized by esterification of biomass derived levulinic acid (LA) with n-hexanol in a closed batch system. Hierarchical-HZ-5 (modified H-ZSM-5) was used as a heterogeneous acid catalyst. There are no reports available on the synthesis of n-hexyl levulinate biolubricant using renewable levulinic acid. The process variables such as catalyst to LA ratio (X-1), n-hexanol to LA molar ratio (X-2), reaction time (X-3) and reaction temperature (X-4) were optimized by response surface methodology (RSM), using the Box-Behnken model. Analysis of variance was done to check the suitability and significance of the quadratic model. The yield of n-hexyl levulinate obtained was 97\% with 100\% selectivity at optimum process parameters. The RSM analysis predicted that catalyst to LA ratio is most significant (value of p \< 0.0001) and n-hexanol to LA molar ratio is least significant (value of p = 0.0064) process parameter in esterification. The quadratic model established was revealed to be suitable and statistically precise with correlation value (R-2) of 0.9837 to predict the yield of n-hexyl levulinate. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

}, keywords = {Agricultural waste feedstock, Esterification, Hierarchical-HZ-5, n-Hexyl levulinate, Optimization, Response surface methodology}, issn = {0957-5820}, doi = {10.1016/j.psep.2015.11.003}, author = {Nandiwale, Kakasaheb Y. and Bokade, Vijay V.} }