Synthesis Of Ethyl Levulinate Research Articles

The influence of catalyst structure on acidic strength of –SO3H groups for alkyl levulinate synthesis from biomass–derived feedstocks using sulfonic acid functionalized flexible MOF catalyst

A Brönsted acidic BUT−8(Cr)–SO3H metal–organic framework was used for the synthesis of ethyl levulinate from two different biomass–derived platform chemicals viz. furfuryl alcohol and levulinic acid. The catalyst was well characterized using various methods such as PXRD, FTIR spectroscopy, acid–base titration, NH3–TPD, TGA–DTA, SEM, TEM as well as the computational density functional theory (DFT) method. The performance of BUT–8(Cr)–SO3H catalysts was found to be superior to other catalysts (HZSM–5, H–Beta, and amberlyst –15) taken in this study. The sulfonic acid moieties bound to the aromatic naphthalene structure of BUT–8(Cr)–SO3H MOF were found to have a much stronger influence on the catalytic performance than the sulfonic acid moieties bound to the styrene framework of amberlyst–15. The key discoveries regarding the Brönsted acidic characteristics were computed via DFT incorporating the hydrogen removal energy, molecular electrostatic potential maps, and stability of the conjugate base of –SO3H moieties. The trend in the DFT–derived values was in the following order: BUT–8(Cr)–SO3H > Linker–naph –SO3H > Amberlyst–15. The results also indicate the influence of Cr metal on MOF structure to increase the acidic strength of the –SO3H group. The reaction optimization using DOE, recyclability, leaching study, and substrate scope study for both pathways using BUT–8(Cr)–SO3H were obtained.

Environmentally sustainable ethyl levulinate synthesis from delignified sugarcane bagasse using ternary eutectic solvent under MW-xenon irradiation: engine performance and emission assessment.

For the first time, a synergistic energy-efficient combination of microwave-xenon (MW-XE) irradiations in presence of photoactive ternary acidic deep eutectic solvents (TADES) has been applied for intensification of ethyl levulinate synthesis from delignified sugarcane bagasse (DSB) under mild (90min, 90°C) and environmentally benign process conditions. The Taguchi orthogonal designed optimized conditions (20 W/cm3 of MW specific irradiation power input, 1 mol/mol of FeCl3 to citric acid ratio, 90min of reaction time, 150 W of XE specific power input) rendered maximum 61.3mol% of EL yield (selectivity: 87.70 [Formula: see text] 0.5%). Remarkably, synergistic effect of MW and XE irradiation significantly enhanced the EL yield (61.3mol%) compared to the individual MW (34.52mol%) and XE (22.67mol%) irradiation at otherwise optimized reaction conditions. Moreover, the MWXE irradiated reactor (MWXER) exhibited a significant 79.10% increase in EL yield compared to the conventional thermal reactor (CTR), at the expense of 10% less energy consumption. The ethyl levulinate could be recovered efficiently through green protocol from reaction mix resulting in high purity (97 [Formula: see text] 0.5%) and TADES was sustainably reused in the process. The optimally generated product EL when blended (5 and 10 vol.%) with B10 and B20 (10% and 20% biodiesel-diesel blend) could provide 21-31% reduction in HC and 7.3-36% reduction in CO in comparison with petro-diesel. It was also explored that, at similar optimal parametric combinations, the TADES produced 29.5% greater EL yield in comparison with the standard ionic liquid BMIMCl. The life cycle environmental impact analysis (LCEIA) of the overall process revealed that the 5 vol.% EL blending with B10 contributed lowest environmental impacts mitigating marine ecotoxicity, human toxicity, fossil depletion, and climate change by 77.9%, 77.4%, 78.4% and 77.5%, respectively.

Effects of Ethanol: Water Ratio and Reaction Time on Ethyl Levulinate Synthesis from Oil Palm Empty Fruit Bunch (OPEFB)

World energy consumption continues to escalate annually in line with current world development. Meeting this burgeoning demand necessitates the exploration of renewable energy. Biofuel is one of the promising alternatives for renewable energy sources. However, biofuel has a disadvantage in its lower overall performance than fossil fuel. The application of additives such as ethyl levulinate emerges as a potential solution to enhance biofuel performance. This research aims to investigate the effect of ethanol:water ratio and reaction time on the formation of ethyl levulinate from Oil Palm Empty Fruit Bunch (OPEFB). The OPEFB to be utilized was pretreated with 3% NaOH at a solid-to-liquid ratio of 1:8. The reaction was conducted at 120oC, with varying ethanol:water ratio and reaction time in the presence of H2SO4 as the catalyst. The reaction products were extracted using ethanol and analyzed with gas chromatography–mass spectrometry. The optimum reaction conditions obtained were 90 minutes and ethanol:water ratio of 99.1:0.9, resulting in a yield of 1.01%.

Synthesis of ethyl levulinate over sulfonated lignin-based carbon catalyst as a fuel additive to biodiesel-diesel blends towards engine emissions

Biodiesel-diesel blend is a promising approach for petroleum diesel substitution but concurrently requires modifications to improve its properties. In this study, ethyl levulinate (EL) was synthesized via levulinic acid (LA) esterification over a sulfonated lignin-based carbon catalyst and employed as an additive to improve biodiesel-diesel blends. The catalyst was prepared from lignin as a carbon precursor, modified via hydrothermal sulfonation at 180 °C for 6 h, and finally characterized. The effects of reaction parameters for LA esterification, such as ethanol-to-LA molar ratio (3–15), catalyst loading (3–20 wt%), and reaction time (2–6 h) were studied. Ethyl levulinate with 80 mol% and 100 mol% concentrations were examined as a fuel additive for palm oil biodiesel-diesel blends of B10, B15, and B20. The effect of the additive on the density and viscosity of biodiesel-diesel blends, as well as carbon monoxide (CO) and nitrogen oxide (NOx) emissions from engine combustion, was investigated. The results show that the catalyst has good acidity (1.30 mmol/g) and suggested thermal stability up to 200 °C, as well as unique surface morphology with a large surface area of 193 m2/g contributed by mesopores and micropores. A high initial yield of EL of 84.3 mol% was obtained over LHS-400-1 at optimum conditions of 6 ethanol-to-LA molar ratio, 15 wt% of catalyst, and 5 h at 80 °C. The reusability study up to five cycles showed a gradual reduction in the LA conversion which indicated catalyst instability. As for the biodiesel-diesel blends, the presence of EL at 3 to 7 vol% reduced the viscosity and slightly increased the density. Furthermore, CO and NOx emissions trends decreased with the addition of EL. The presence of LA in 80 mol% EL for biodiesel-diesel blends resulted in slightly high CO and NOx emissions as compared to the blends with 100 mol% EL.

One-pot method of recyclable lipase-nanocatalyst based on chitosan magnetic nanomaterial for ethyl levulinate synthesis

Carrier, immobilization method and conditions are the most important factors affecting the performance of immobilized lipase. In this study, MNP@CTS is successfully prepared via an improved hydrothermal method combined with ion condensation. Then, we creatively adopt one-pot method, combining electrostatic adsorption with chemical crosslinking, to prepare lipase-nanocatalyst with excellent performance under mild conditions. MNP@CTS and lipase-nanocatalyst are characterized by FTIR, SEM, HRTEM, CLSM, CD, etc, the optimal conditions are explored in detail too. Lipase-nanocatalyst is 189 nm, and the loading ratio of free lipase is up to 67.6%. Compared with free lipase, specific activity is increased by 2.9 times, and it also broadens toleration to pH, thermal, organic solvents. In addition, lipase-nanocatalyst exhibits high storage stability and reusability. The residual activity is approximately 92.3% after the 10th recycle, and the cumulative catalytic activity is 13.4 times than that of free lipase. Finally, lipase-nanocatalyst is used to synthesize ethyl levulinate, with a production ratio of 68.6% for the first recycle, and the total output of EL is 12.9 times than that of free lipase after ten cycles. Thus, our findings provide a foundation for lipase-nanocatalyst showing several attractive features, such as easy preparation, excellent catalytic activity, good stability and reusability.

Kinetics and structural design of ZSM-5@SiC foam catalytic packing in RD column for ethyl levulinate synthesis

Reactive distillation (RD) column is one of the important equipment to improve the reaction conversion limited by the chemical equilibrium, however, the application in industrial scale is still challenging due to the lack of efficient catalytic packing with corresponding kinetics and separation performances. This work developed the novel catalytic packing consists of the structured ZSM-5@SiC foam catalyst and corrugated sheet, which is used in RD for the synthesis of ethyl levulinate (EL). The results of X-ray CT characterization revealed that the structure of ZSM-5@SiC has significant effects on the kinetics and performances of RD column. The kinetic of structured ZSM-5@SiC foam catalyst was measured, and a novel kinetic model was developed regarding the “structure factor” of ZSM-5@SiC catalyst. Furthermore, the structural design of ZSM-5@SiC in RD column has been firstly performed based on the developed kinetics that was incorporated into Aspen Plus embedded FORTRAN. The results demonstrated excellent performance of the designed ZSM-5@SiC (EL yield 37.65 % with energy consumption 3695 kJ/kg) are achieved. Such findings in this work could serve as a tool for further upgrading of structured catalyst and application of RD column with ZSM-5@SiC foam catalytic packing.

Synthesis of ethyl levulinate from furfuryl alcohol using waste yeast/sulfonic acid heterogeneous catalyst system

Synthesis of ethyl levulinate from furfuryl alcohol using waste yeast/sulfonic acid heterogeneous catalyst system

Nano-H-ZSM-5 with Short b-Axis Channels as a Highly Efficient Catalyst for the Synthesis of Ethyl Levulinate from Furfuryl Alcohol

For the ethanolysis of biomass-derived furfuryl alcohol (FA) to value-added ethyl levulinate (EL), the development of an efficient solid acid catalyst is very important for industrial application with high FA concentration. Herein, a H-ZSM-5 catalyst with nano b-axis channels (NB-H-ZSM-5) was synthesized and used for the conversion of FA. Detailed catalyst characterization proved that the NB-H-ZSM-5 catalysts (Si/Al = 25∼125) with ∼70 nm b-axis channels were successfully prepared. The NB-H-ZSM-5 catalyst with Si/Al = 75 showed the highest activity. Its structural characteristics allowed for fast diffusion of reactants and products and full utilization of active sites, which endowed it with higher activity compared to commercial H-ZSM-5 (C-H-ZSM-5). Its moderate acidity effectively inhibited the polymerization of FA even at a high FA concentration of 20 wt %. The spent catalyst was easily regenerated by coke burn-off to give a good recyclability. Furthermore, based on the proposed reaction network, a method of physically mixing the NB-H-ZSM-5 (75) catalyst with a small amount of Amberlyst-15 was proposed to further increase the EL yield from 64.7 to 82.1% at an FA concentration of 6 wt %.

Synthesis of ethyl levulinate from cellulose over a double acid site catalyst

AbstractBACKGROUNDA novel double acid site solid catalyst (Al‐OCS‐0.1) having an ordered mesoporous structure was synthesized by grafting sulfonic acid groups on an oxidized ordered mesoporous carbon (OOMC) support and loading 10% Al2(SO4)3.RESULTAssessments using Field emission scanning electron microscopy, Transmission electron microscopy and X‐ray diffraction showed that the OMC structure remained unchanged after the chemical modification and Al2(SO4)3 loading. The Brunauer–Emmett–Teller surface area and average pore size of Al‐OCS‐0.1 decreased to 181 m2 g−1 and 7.1 nm after loading Al2(SO4)3, respectively. Ammonia temperature‐programmed desorption (NH3‐TPD) and Pyridine adsorption infrared spectroscopy (Py‐IR) demonstrated that Al‐OCS‐0.1 had abundant Brønsted and Lewis acid sites. The ammonia desorption of Al‐OCS‐0.1 increased from 2.0 to 7.2 mmol g−1 after loading Al2(SO4)3.CONCLUSIONThe Al‐OCS‐0.1 was used to catalyze the synthesis of ethyl levulinate from cellulose in ethanol and gave an extremely high yield of 50.8 mol% after 5 h at 200 °C. © 2021 Society of Chemical Industry (SCI).

Efficient one-pot synthesis of ethyl levulinate from carbohydrates catalyzed by Wells-Dawson heteropolyacid supported on Ce–Si pillared montmorillonite

Efficient conversion of biomass-derived carbohydrates to alkyl levulinates is an important goal of biorefinery process, but is still challenging on applicable catalyst. Ce–Si pillared montmorillonite (CeSiM) clay heterostructures, incorporated with Wells-Dawson tungstophosphoric acid (H6P2W18O64, DPW), were prepared for the first time and used as the multifunctional catalyst for direct production of ethyl levulinate (EL) from various biomass-derived sugars. The DPW introduced by sol-gel method (DPW-CeSiM) has been effectively incorporated into the framework of porous CeSiM, while part of DPW was just absorbed on the surface of CeSiM by impregnation method (DPW-CeSiM-I). The DPW-CeSiM catalyst has large specific surface area owing to the insertion of Ce–Si pillars, and possesses strong Brønsted acidity and moderate Lewis acidity originated from the incorporated DPW and the Ce-doping, respectively. Due to the well synergistic effect of porous structure and dual acid, the DPW-CeSiM catalyst efficiently catalyzed the conversion of glucose into EL with 56.2% yield and nearly 100% conversion at 170 °C for 4 h. The recyclability studies certified that DPW-CeSiM catalyst showed higher stability than DPW-CeSiM-I over cycles and could be easily recovered from consecutive alcoholysis of biomass-derived sugars. The DPW-CeSiM catalyst also displayed high activity toward the conversion of other biomass-derived carbohydrates (fructose, sucrose, cellobiose and cellulose) into EL. Therefore, this work provides an instructive strategy for the design of efficient and stable DPW-based catalysts with dual acid sites uniformly distributed over the porous structure, which is obviously potential for industrial production of alkyl levulinates from carbohydrates and biomass.

Reactive Chromatography Applied to Ethyl Levulinate Synthesis: A Proof of Concept

Levulinic acid (LA) has been highlighted as one of the most promising platform chemicals, providing a wide range of possible derivatizations to value-added chemicals as the ethyl levulinate obtained through an acid catalyzed esterification reaction with ethanol that has found application in the bio-fuel market. Being a reversible reaction, the main drawback is the production of water that does not allow full conversion of levulinic acid. The aim of this work was to prove that the chromatographic reactor technology, in which the solid material of the packed bed acts both as stationary phase and catalyst, is surely a valid option to overcome such an issue by overcoming the thermodynamic equilibrium. The experiments were conducted in a fixed-bed chromatographic reactor, packed with Dowex 50WX-8 as ion exchange resin. Different operational conditions were varied (e.g., temperature and flow rate), pulsing levulinic acid to the ethanol stream, to investigate the main effects on the final conversion and separation efficiency of the system. The effects were described qualitatively, demonstrating that working at sufficiently low flow rates, LA was completely converted, while at moderate flow rates, only a partial conversion was achieved. The system worked properly even at room temperature (303 K), where LA was completely converted, an encouraging result as esterification reactions are normally performed at higher temperatures.

Alkyl Levulinates from Furfuryl Alcohol Using CT151 Purolite as Heterogenous Catalyst: Optimization, Purification, and Recycling

Commercially available Purolite CT151 demonstrated to be an efficient acid catalyst for the synthesis of alkyl levulinates via alcoholysis of furfuryl alcohol (FA) at mild temperatures (80–120 °C) and short reaction time (5 h). Reaction conditions were first optimized for the synthesis of ethyl levulinate and then tested for the preparation of methyl-, propyl-, isopropyl-, butyl, sec-butyl- and allyl levulinate. Preliminary scale-up tests were carried out for most of the alkyl levulinates (starting from 5.0 g of FA) and the resulting products were isolated as pure by distillation in good yields (up to 63%). Furthermore, recycling experiments, conducted for the preparation of ethyl levulinate, showed that both the Purolite CT151 and the exceeding ethanol can be recovered and reused for four consecutive runs without any noticeable loss in the catalyst activity.

Direct conversion of cellulose to ethyl levulinate catalysed by modified fibrous mesoporous silica nanospheres in a co-solvent system

A KCC-1/Al–SO3H catalyst with Si/Al = 5 was prepared to directly catalyse the synthesis of ethyl levulinate from cellulose in an ethanol/toluene co-solvent system. A reaction yield of 28.8 mol% was achieved after 6 h at 200 °C.

Design of Brønsted acidic ionic liquid functionalized mesoporous organosilica nanospheres for efficient synthesis of ethyl levulinate and levulinic acid from 5-hydroxymethylfurfural

Mesoporous organosilica nanosphere-immobilized Brønsted acidic ionic liquids with a controlled particle size and pore morphology exhibit high activity and selectivity.

Ethyl levulinate synthesis from biomass derivative chemicals using iron doped sulfonated carbon cryogel catalyst

Biomass-derived intermediate chemicals, such as furfuryl alcohol (FA) and levulinic acid (LA) are feeds for ethanolysis reaction to produce ethyl levulinate (EL). EL is a promising chemical that can be used as a biofuel additive and precursor for chemical synthesis, such as γ-valerolactone. The present study conducted the ethanolysis of FA and LA using modified carbon cryogel as heterogeneous catalysts for improving the EL yield. The carbon cryogel (UCC) precursor was produced from urea and furfural, and modified via sulfonation. Iron (Fe) doping was then conducted to improve the surface chemistry of the catalyst. The catalytic activity of sulfonated carbon cryogel (UCC-S) was evaluated for LA ethanolysis, and the UCC-S-Fe prepared from the incorporation of Fe on UCC-S was utilised to catalyse FA ethanolysis. The effects of reaction parameters (i.e., time, molar ratio of ethanol to feed, catalyst loading, and reaction temperature) were significant on the catalytic performance. High EL yield of 95.8 mol% and 95.4 mol% were obtained from the ethanolysis of LA and FA, respectively. The performance of ethanolysis of carbohydrates and various biomass samples was evaluated to determine the EL yield using UCC-S-Fe. Both UCC-S and UCC-S-Fe were characterised using FTIR, XRD, TGA, NH3-TPD, BET, and SEM-EDX. The modification of UCC via sulfonation and Fe-doping improved the catalyst properties, and UCC-S-Fe demonstrated the potential to enhance biomass conversion to EL.

Efficient conversion of glucosamine to ethyl levulinate catalyzed by methanesulfonic acid

This study is focused on the possibility of using crustacean waste shells for sustainable biofuels and chemical production. We investigated the synthesis of ethyl levulinate (EL) from glucosamine by the methanesulfonic acidcatalyzed hydrothermal reaction using Box-Behnken design. In the ethyl levulinate synthesis, higher water content highly inhibited the formation of EL. Among the reaction factors, reaction temperature, catalyst concentration, and reaction time positively affected the outcome more than substrate concentration. The optimized reaction conditions were 200 °C reaction temperature, 60 g/L substrate concentration, 0.75 M catalyst concentration, and 44.9 min. Under these conditions, a 22.76 mol% EL yield was achieved. These results suggest that crustacean waste shells can be used for renewable feedstocks to produce valuable chemicals and biofuels.

Sulfonated porous biomass-derived carbon with superior recyclability for synthesizing ethyl levulinate biofuel

The synthesis of ethyl levulinate (EL) via esterification of levulinic acid (LA) with ethanol, which can be derived from biomass, has become an attractive topic since EL can be applied in many fields, such as fuel additives for petroleum and biodiesel, food additives and fragrance. Herein, the sulfonated porous carbon catalysts derived from the rinds of corn stalk biomass wastes were prepared by using sulfuric acid and phosphoric acid as the sulfonating agent and activator, respectively. The preparation parameters were optimized based on the catalytic activity for LA esterification with ethanol and the acid density of the corresponding catalysts. Also, various reaction factors were optimized to improve the catalytic efficiency over the optimal sulfonated corn stalk-derived carbon (s-CSC). Under the conditions of reaction temperature 80 °C, catalyst dosage 5 wt%, ethanol-to-LA molar ratio 5.0:1 and reaction time 8 h, the LA conversion reached 94% and 93% catalyzed by s-CSC and the optimal porous catalyst (s-p-CSC), respectively. Noticeably, benefitting from the hierarchical porous structure with large surface area, s-p-CSC exhibited much better recyclability than s-CSC. This work offers a highly effective solid acid catalyst for the synthesis of biofuel.

Intraparticle diffusion model to determine the intrinsic kinetics of ethyl levulinate synthesis promoted by Amberlyst-15

Levulinic acid and its esters are considered very versatile chemical compounds used for a wide range of derivatives. Traditionally ethyl levulinate is synthesized in batch reactors, using homogeneous catalysts (H2SO4, H3PO4). Several investigations were reported on solid acid catalysts, as zeolites, sulfated oxides, sulfonic ion-exchange resins. Amberlyst-15 showed high potentials: to design a continuous reactor, it is necessary to investigate the stability of the catalyst and the kinetics of the reaction. In the present work, we demonstrated that the resin is stable for more than 5 days. Kinetic and mass transfer phenomena were studied, evaluating the partition and take-up of the used resin when put in contact with reactants and products. Two different samples of Amberlyst-15 were used, characterized by different size, demonstrating that bigger particles lead to higher intraparticle diffusion limitations.

Synthesis of ethyl levulinate over amino-sulfonated functional carbon materials

Functional carbon materials (FCM) containing amino and sulfonate groups (NS-FCM) were prepared with one-pot hydrothermal carbonization of cellulose using ammonium formate and 5-sulfosalicylic acid additives. The catalytic materials were applied to levulinic acid or furfuryl alcohol substrates in ethanol solvent for synthesizing ethyl levulinate (EL). Catalytic activity of NS-FCM was found to be related to its sulfonate groups, while substrate selectivity of NS-FCM was found to be related to its amino groups as supported by equilibrium adsorption and reaction experiments. Pre-adsorbed LA substrate onto NS-FCM followed by ethanol treatment at reaction conditions achieved EL yields higher than 90% that is attributed to a selective adsorption and cooperative desorption mechanism. The activity of NS-FCM catalyst was stable for five reuse cycles, but lost about 10% of its activity from the third cycle that is attributed to adsorption of humin precursors onto active sites.

Direct conversion of sugar into ethyl levulinate catalyzed by selective heterogeneous acid under co-solvent system

The direct synthesis of ethyl levulinate (EL) from sucrose was investigated under co-solvent of tetrahydrofuran (THF)/ethanol over stable/active heterogeneous acid catalyst. Several Lewis acid-metal oxides were doped onto Brønsted acid-sulfonated carbon (SC) and the results found that Zn-SC exhibited highest activity for production of EL from sucrose conversion of 100% with a selectivity of 72.1%. The catalytic mechanism for conversion of sucrose into EL and other products was investigated through significant effects such as catalyst type, co-solvent and ultrasonic application. The catalyst reusability test exhibited high stability for five cycles and then dramatically decreased without any regeneration process.