Esterification of levulinic acid to ethyl levulinate over bimodal micro–mesoporous H/BEA zeolite derivatives (original) (raw)
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Selective Synthesis of Levulinic Ester from Furfural Catalyzed by Hierarchical Zeolites
Catalysts
Furfural is a platform molecule that can be catalytically converted using a cascade series of reactions into levulinic esters, essential compounds used as fuel additives. Bifunctional catalysts containing Lewis and Brønsted acid sites such as zeolites are commonly used for these conversions. However, microporous zeolites often present diffusional restriction due to the size similarity of furfural and other molecules to the zeolites’ micropores. Thus, incorporating mesopores in these materials through post-synthetic protocols is a promising pathway to circumventing these limitations. This study presents the creation of hierarchical beta and mordenite using Si or Al removal and their employment in the furfural conversion to isopropyl levulinate (PL). Mordenite zeolite did not produce satisfactory mesopores, while the beta was more efficient in generating them by both acid and alkaline treatments. Beta zeolite treated in an alkaline solution presented larger mesopores (14.9 and 34.0 nm...
Levulinic acid esterification with ethanol to ethyl levulinate production over solid acid catalysts
Applied Catalysis A: General, 2012
Levulinic acid is considered as a versatile building block because it can be used for the synthesis of several organic chemicals. In particular, its esterification with ethanol produces ethyl levulinate that can be used as diesel miscible biofuel (DMB), preventing global warming by decreasing atmospheric CO 2 generated from the consumption of fossil fuels. This article explores the use of two groups of solid acid catalysts (sulfated oxides and zeolites with different pore structures) in the esterification of levulinc acid with ethanol aiming for ethyl levulinate production. It was found that while there is a correlation between the number of acidic sites and activity for the sulfated oxides, the same is not true for the studied zeolites where the pore channels play a more important role. Among the catalysts tested, Amberlyst-15 and sulfated SnO 2 showed a remarkable high yield of ethyl levulinate that was probably due to the strong acidity provided by SO 3 H functional groups and SO 4 species, respectively.
Journal of Porous Materials, 2019
A comparative study of different heteropoly acids supported on mesoporous AlSBA-15 for the synthesis of ethyl levulinate has been undertaken for the first time. The catalysts were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma-optical emission spectrometry, thermo gravimetric analysis, temperature programmed desorption of NH 3 and N 2 sorption studies. Insights into crucial parameters for the esterification reactions are also furnished. A distinct correlation was observed between acid density and conversion revealing that the distribution of acidic sites and their accessibility by the reactant moieties plays an important role in determining the overall activity. The effects of various reaction parameters were investigated to enhance the catalytic activity and yield of ethyl levulinate. Under the optimized conditions, levulinic acid conversion of 87.4 mol% and ethyl levulinate selectivity of 100% could be obtained with silicotungstic acid supported on AlSBA-15.
Microporous and Mesoporous Materials, 2007
Micro/mesoporous materials with different contribution of micro-and mesoporosity were prepared by recrystallization of zeolite BEA in alkaline solution in the presence of cethyltrimethylammonium bromide. The materials were characterized by XRD, nitrogen adsorption-desorption and IR spectroscopy of adsorbed probe molecules. It has been demonstrated that the degree of recrystallization can be adjusted by variation of concentration of NaOH in solution. Recrystallization in mild conditions did not significantly affect the amount and strength of acid sites but resulted in the improvement of their accessibility for bulky probe molecules due to the creation of mesopores. The increase of the degree of recrystallization led first to partial and then to complete transformation of BEA into MCM-41 followed by a gradual decrease of the amount and strength of Brønsted sites and the increase of the contribution of Lewis sites to the total amount of sites.
Catalytic conversion of linalool on micro-mesoporous BEA-type zeolite
2017
The catalytic conversion of the tertiary terpenic alcohol linalool (C 10 H 18 O) on samples of the beta type microporous zeolites (BEA-25 and BEA-150 with n(SiO 2)/n(Al 2 O 3) equal to 25 and 150) and on their modified micro-mesoporous forms (RBEA-25 and RBEA-150 with n(SiO 2)/n(Al 2 O 3) equal to 23.8 and 176.4, and transport mesopores with pore diameters 3.5 and 3.8 nm, respectively)was studied. The micro-mesoporous materials were synthesized by recrystallization of initial commercial BEAzeolites in NaOH aqueous solutions. The chemical composition of the catalysts was determined using X-ray fluorescence analysis. The micro-and mesopores volumes and specific surface areas of catalysts were defined by nitrogen adsorption-desorption. The acid properties of catalysts were estimated using temperature-programmed desorption of ammonia. The catalytic conversion of linalool was carried out in a static system in the liquid phase. The analysis of products of catalytic reactions was carried out by the GC-MS. The reactions of isomerization, dehydration, cyclization and condensation of linalool take place on the studied micro-and micro-mesoporous zeolites by the conversion of linalool in an atmosphere of nitrogen or argon in a liquid phase at 60-170 °C. The conversion of linalool (4-40%) and the selectivity (45-12 %) of the formation of nerol and geraniol as products of linalool isomerization are low. The introduction of mesopores in the microporous BEA-type zeolite catalysts leads to a significant increase in conversion of linalool and a slight growth in selectivity towards nerol and geraniol. Comparatively high amount of weak acid sites in microporous BEA zeolites contributes to enlarge in selectivity. ©2017 Bull. Georg. Natl. Acad. Sci.
Applied Catalysis A: General, 2013
Sulfonic mesoporous silicas have demonstrated an outstanding catalytic performance in the esterification of levulinic acid with different alcohols to produce alkyl levulinates, a family of chemicals considered to be excellent oxygenated fuel extenders for gasoline, diesel and biodiesel. Catalyst screening indicated that propylsulfonic acid-modified SBA-15 material was the most active one, among tested materials, due to a combination of moderately strong sulfonic acid sites with relative high surface hydrophobicity. Under optimized reaction conditions (T = 117 ºC, ethanol/levulinic acid molar ratio = 4.86/1 and catalyst/levulinic acid = 7 wt.%) almost 100% of levulinic acid conversion was achieved after 2 h of reaction, being negligible the presence of levulinic acid by-products or ethers coming from intermolecular dehydration of alcohols. The catalyst has been reused, without any regeneration treatment, up to three times keeping almost the high initial activity. Interestingly, a close catalytic performance to that achieved using ethanol has been obtained with bulkier alcohols.
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 Brönsted 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 R2 > 0.99, using the experimental data. A P-H kinetic model implies that, the esterification reaction follows second order reversible kinetics. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 795–801, 2015
Biomass Conversion and Biorefinery, 2021
Oil palm biomass, which is abundantly available in Malaysia, has many types of applications in various industries. In this study, oil palm frond (OPF) was liquefied with 1-butyl-3-methylimidazole hydrogen sulfate ([BMIM][HSO 4 ]) ionic liquid (IL) at optimum conditions. The liquefied OPF-ionic liquid (LOPF-IL) was mixed with furfural at a ratio of 0.8 (w/w), water-tofeedstock ratio of 0.125 (w/w), and sulfuric acid loading of 0.5 mL at 100°C for 1 h to form a gel. Carbon cryogel liquefied oil palm frond (CCOPF) was prepared using a freeze-dryer followed by calcination. CCOPF was further characterized using N 2 sorption, NH 3-TPD, TGA, XRD, FTIR, and FESEM to determine its physical and chemical properties. The thermally stable CCOPF exhibited a large total surface area (578 m 2 /g) and high total acidity (17.6 mmol/g). Next, CCOPF was tested for levulinic acid catalytic esterification by varying the parameters including ethanol-to-levulinic acid molar ratio, catalyst loading, and reaction time at 78°C. At the optimum conditions, the conversion of levulinic acid and ethyl levulinate yield was 70.9 and 71.7 mol%, respectively. CCOPF was reusable up to five runs with no significant conversion drop. Accordingly, CCOPF is conferred as a potential biomass-derived acid catalyst for ethyl levulinate production. Keywords Oil palm frond. Biomass. Liquefaction. 1-Butyl-3-methylimidazole hydrogen sulfate. Carbon cryogel. Ethyl levulinate Highlights • Liquefaction of oil palm frond with [BMIM][HSO 4 ] ionic liquid yielded LOPF-IL mixture. • Synthesis of carbon cryogel liquefied OPF (CCOPF) from LOPF-IL and furfural. • Good surface properties and high thermal stability are exhibited by microspherical CCOPF. • Esterification of levulinic acid is conducted over biomass-derived CCOPF catalyst.
Catalytic Conversion of Glucose to Levulinic Acid Using Zeolite Immobilized Ionic Liquid as Catalyst
2016
Concerns towards diminishing fossil resources compel the chemical industry to explore alternatives for basic chemical productions. Carbohydrates derived biomass are promising alternatives for sustainable supply of fuels and valuable chemicals due to their abundant and relatively inexpensive properties. Carbohydrate such as glucose is a compound from which various bio-based chemicals can be derived. Among those chemicals, levulinic acid (LA) has received significant attention as platform chemicals for synthesizing a broad range of bio-based fuels. The conversion of carbohydrates to LA have been conducted in water in the presence of various catalysts, including homogeneous and heterogeneous catalysts. In this study, a new zeolite immobilized ionic liquid (HY-IL) catalyst has been explored for catalytic conversion of glucose to LA. The catalyst was prepared by immobilizing an acidic ionic liquid; 1,4 methylsulfonic acid imidazolium tetrachloroaluminate ([MSIM][AlCl4]) into HY zeolite w...
Esterification of Levulinic Acid to Methyl Levulinate over Zr-MOFs Catalysts
ChemEngineering, 2022
At present, the trend towards partial replacement of petroleum-derived fuels by those from the revaluation of biomass has become of great importance. An effective strategy for processing complex biomass feedstocks involves prior conversion to simpler compounds (platform molecules) that are more easily transformed in subsequent reactions. This study analyzes the metal–organic frameworks (MOFs) that contain Zr metal clusters formed by ligands of terephthalic acid (UiO-66) and aminoterephthalic acid (UiO-66-NH2), as active and stable catalysts for the esterification of levulinic acid with methanol. An alternative synthesis is presented by means of ultrasonic stirring at room temperature and 60 °C, in order to improve the structural properties of the catalysts. They were analyzed by X-ray diffraction, scanning electron microscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, microwave plasma atomic emission spectroscopy, acidity measurement, and N2 adsorption. The catalytic ...