Month: December 2022

Nguyen, Hoang Chinh published the artcileMicrowave-mediated noncatalytic synthesis of ethyl levulinate: A green process for fuel additive production, Synthetic Route of 539-88-8, the main research area is ethyl levulinate microwave irradiation noncatalytic synthesis fuel additive production.

This study developed a new catalyst-free process for producing Et levulinate, a biofuel additive. Noncatalytic levulinic acid esterification with ethanol using microwave irradiation (MW) was compared with that using traditional heating (TH) under different reaction conditions. The results demonstrated that the esterification process using MW was more effective than that using TH. A reaction conversion of 90.38% was obtained for the esterification using MW at 473 K and reaction time of 3 h. Moreover, this study established a model for depicting the kinetics of levulinic acid esterification using MW and TH. A good fit to the data (R2 of >.9999) was achieved, indicating the validity of the developed model. The rate constants and pre-exponential factor obtained for the esterification using MW were greater than those obtained using TH. Consequently, the microwave-assisted noncatalytic synthesis is a green and promising method for preparing Et levulinate.

International Journal of Energy Research published new progress about Activation energy. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Synthetic Route of 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Lai, Jinhua published the artcileCatalytic Transfer Hydrogenation of Biomass-Derived Ethyl Levulinate into Gamma-Valerolactone Over Graphene Oxide-Supported Zirconia Catalysts, Product Details of C7H12O3, the main research area is ethyl levulinate valerolactone graphene oxide zirconia catalytic transfer hydrogenation.

Abstract: The transformation of biomass-derived intermediates into value-added chems. and liquid fuels is of great importance in sustainable chem. In this study, graphene oxide supported ZrO2 (ZrO2/GO) was found to be an active heterogeneous catalyst for the transfer hydrogenation of Et levulinate to γ-valerolactone (GVL) with iso-propanol as the hydrogen donor. Several important reaction parameters such as the hydrogen donor, the reaction temperature and the catalyst loading were studied in detail with the aim to get a high yield of GVL. It was found that the structure of alcs. had a great effect towards the activity of the ZrO2/GO catalyst and the selectivity of GVL. Iso-propanol was the best hydrogen donor for the transfer hydrogenation of Et levulinate to GVL. The highest GVL yield reached 91.7% with an Et levulinate conversion of 96.2% under optimal reaction conditions. More importantly, the ZrO2/GO catalyst demonstrated a high stability without the loss of its catalytic activity during the recycling experiments, which should be due to the strong interaction between GO and ZrO2. Graphical Abstract: The graphene oxide supported ZrO2 (ZrO2/GO) catalyst showed high activity for the transfer hydrogenation of Et levulinate to GVL with a high yield up to 91.7%.[Figure not available: see fulltext.].

Catalysis Letters published new progress about Activation energy. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Product Details of C7H12O3.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Ahmad, Ejaz published the artcileUnderstanding reaction kinetics, deprotonation and solvation of bronsted acidic protons in heteropolyacid catalyzed synthesis of biorenewable alkyl levulinates, Safety of Ethyl 4-oxopentanoate, the main research area is levulinic acid heteropolyacid catalyst esterification kinetics IR spectra.

In search of a ‘descriptor’ for Bronsted acid-catalyzed biorenewable transformations in a complex reaction environment, two concepts related to the reactivity of Bronsted acid catalysts are explored. A simple reaction involving the esterification of levulinic acid in three different alc. mediums (ethanol, 1-propanol, and 1-butanol) is experimented with two different Keggin heteropolyacid (HPA) catalysts to synthesize alkyl levulinates. On the same HPA catalyst, and different solvent medium, apparent activation energies of the esterification reaction are observed to increase by an average of âˆ? kJ/mol on increasing the alkyl chain length of the alc. medium by one carbon. Obtained apparent activation energies are corresponding with the solvation energies of the Bronsted proton in the resp. alc. medium. In contrast, on changing the HPA catalyst and keeping the same alc. medium, the apparent activation energies are observed to differ by an average of âˆ?9 kJ/mol. This directly correlates with the difference (âˆ?0 kJ/mol) in the vapor phase deprotonation energies (DPE) of the two HPA catalysts. Thus, in the solvent environment, DPE values and the degree of solvation of the Bronsted acidic protons are describing the reactivity of the HPA catalysts.

Chemical Engineering Journal (Amsterdam, Netherlands) published new progress about Activation energy. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Safety of Ethyl 4-oxopentanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Yu, Xin published the artcileEthylene glycol co-solvent enhances alkyl levulinate production from concentrated feeds of sugars in monohydric alcohols, SDS of cas: 539-88-8, the main research area is alkyl levulinate production ethylene glycol monohydric alc concentrated feed.

Conversion of carbohydrates at concentrated feeds represents highly desirable for the industrial deployment of biobased fuels and chems. but challenging. One key bottleneck is that the excessive formation of polymeric humins greatly diminishes the utilization rate of feedstocks and the destination product yield. We report that the use of ethylene glycol as co-solvent for acid-catalyzed conversion of concentrated sugars enhances desirable alkyl levulinate (AL) production compared to reactions carried out in single monohydric alcs. (e.g., methanol, ethanol). Ethylene glycol served not only as a solubilizer of sugars in the reaction medium to lessen their tendency to polymerize by protecting reactive hydroxyl groups in sugars with alcs., but also as a supporter to restrain the condensation of furan intermediates. With 10 vol% ethylene glycol as the co-solvent of ethanol, an improved yield of Et levulinate (EL) from 45% to 56% was accomplished from concentrated feeds of glucose (200 g/L). In particular, high space time yield and EL concentration resp. up to 30 kg/m3·h and 90 g/L were obtained in a batch reactor. The solvents and catalyst could be isolated from the products, and showed good reusability. This contribution opens a reliable avenue for converting highly concentrated feeds of biomass-related sugars to oxygenated liquid fuels and versatile chems.

Fuel published new progress about Activation energy. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, SDS of cas: 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

da Silva, Evellyn Patricia Santos published the artcileInvestigation of solvent-free esterification of levulinic acid in the presence of tin(IV) complexes, Synthetic Route of 539-88-8, the main research area is tin complex catalyst levulinic acid solvent free esterification.

In this study, for the first time, the use of dibutyltin dichloride (Bu2SnCl2), dimethyltin dichloride (Me2SnCl2), butyltin trichloride (BuSnCl3) and Bu stannoic acid (BuSnO(OH)) as catalysts in the esterification of levulinic acid (LA) was investigated through a comparison with reactions performed without the use of a catalyst. The most active system (BuSnCl3) led to 93% conversion of LA in 360 min at 110°C with an LA:EtOH:CAT molar ratio of 1:5:0.01. The apparent rate constants (kap) for LA conversion confirm these results, and values of 6.2 × 10-3, 12.5 × 10-3 and 19.4 × 10-3 min-1 were obtained at 70, 90 and 110°C, resp. The activation energy for LA conversion was determined employing BuSnCl3 and the value was 31.2 kJ mol-1.

Molecular Catalysis published new progress about Activation energy. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Synthetic Route of 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Ye, Lei published the artcileHZ-ZrP Catalysts with Adjustable Ratio of Bronsted and Lewis Acids for the One-Pot Value-Added Conversion of Biomass-Derived Furfural, Computed Properties of 539-88-8, the main research area is catalyst adjustable ratio Bronsted Lewis acid pot biomass furfural.

Bifunctional heterogeneous catalysts (HZ-ZrP) were prepared by using HZSM-5 as the carrier to support zirconium phosphate (ZrP) active component for the one-pot value-added conversion of biomass-derived furfural (FAL). By changing the loading amount of ZrP, the ratio of Lewis to Bronsted acid (2.7-15.4) and the acid strength of the catalysts can be adjusted. HZ-ZrP-5 and HZ-ZrP-16 were selected for the production of different value-added chems., and a total yield of up to 93.8% (i-PL and GVL) and 64.2% (GVL) were obtained using isopropanol as the hydrogen donor under optimized conditions, resp. Furthermore, stability and recyclability of the catalyst were also tested and showed no significant drop in total yield after re-calcination. The catalysts have high activity (Ea = 27.05 ± 3.08 kJ mol-1), but the ring-opening reaction restricted the cascade reaction. In addition, possible reaction pathway and mechanism for the FAL conversion was proposed.

ACS Sustainable Chemistry & Engineering published new progress about Activation energy. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Computed Properties of 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Peng, Wen-Li published the artcileAccelerating Biodiesel Catalytic Production by Confined Activation of Methanol over High-Concentration Ionic Liquid-Grafted UiO-66 Solid Superacids, Name: Methyl docosanoate, the main research area is biodiesel production catalyst metal organic framework ionic liquid; crystalline microporous ordered solid superacid methanol heterogeneous transesterification.

Solid acids usually show lower catalytic activities than liquid acids because of their limited acid strength and presence of obvious diffusion limitation in the reactions. We report herein a variety of ionic liquid-grafted UiO-66 solid superacids synthesized from quaternization of UiO-66 with 1,3-propane sultone, ion-exchanging with H2SO4 or HSO3CF3. The developed UiO-66 solid superacids are highly efficient in catalyzing biodiesel production toward transesterification, which were better than the ionic liquid and neat H2SO4. The remarkable activities found in the UiO-66 solid superacids benefit from the synergistic effect of high acid concentrations (~3.33 mmol/g), superacidity (determined by 31P solid-state NMR, Hammett indicators, and potentiometric titration), as well as unique shape-selective confinement for methanol into the ordered and uniform micropores, which targeted the activation of methanol to prevent the occurring of an inverse reaction in the reactions. The UiO-66 solid superacids show important application potentials in the area of biodiesel production in the industry.

ACS Catalysis published new progress about Activation energy. 929-77-1 belongs to class esters-buliding-blocks, name is Methyl docosanoate, and the molecular formula is C23H46O2, Name: Methyl docosanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Casiello, Michele published the artcileZnO/ionic liquid catalyzed biodiesel production from renewable and waste lipids as feedstocks, SDS of cas: 929-77-1, the main research area is zinc oxide ionic liquid catalyst biodiesel renewable waste lipid.

A new protocol for biodiesel production is proposed, based on a binary ZnO/TBAI (TBAI = tetrabutylammonium iodide) catalytic system. Zinc oxide acts as a heterogeneous, bifunctional Lewis acid/base catalyst, while TBAI plays the role of phase transfer agent. Being composed by the bulk form powders, the whole catalyst system proved to be easy to use, without requiring nano-structuration or tedious and costly preparation or pre-activation procedures. In addition, due to the amphoteric properties of ZnO, the catalyst can simultaneously promote transesterification and esterification processes, thus becoming applicable to common vegetable oils (e.g., soybean, jatropha, linseed, etc.) and animal fats (lard and fish oil), but also to waste lipids such as cooking oils (WCOs), highly acidic lipids from oil industry processing, and lipid fractions of municipal sewage sludge. Reusability of the catalyst system together with kinetic (Ea) and thermodn. parameters of activation (ΔGâ€?and ΔHâ€? are also studied for transesterification reaction.

Catalysts published new progress about Activation energy. 929-77-1 belongs to class esters-buliding-blocks, name is Methyl docosanoate, and the molecular formula is C23H46O2, SDS of cas: 929-77-1.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Meng, Qinghui published the artcileA theoretical investigation on Bell-Evans-Polanyi correlations for hydrogen abstraction reactions of large biodiesel molecules by H and OH radicals, Application of Methyl decanoate, the main research area is hydrogen hydroxide biodiesel combustion activation energy enthalpy rate constant.

High-accuracy prediction of activation energies and enthalpies of reaction is theor. important while computationally challenging for accurately determining the kinetic para. of chem. reactions in biodiesel combustion. In practice, the Bell-Evans-Polanyi (BEP) correlations between the activation energy and the enthalpy of reaction play an important role in fast estimation with acceptable accuracy. In the present study, the BEP correlations for hydrogen abstraction reactions of biodiesel surrogates by H and OH radicals were theor. investigated by using high-level orbital-based and ONIOM-based methods. Reaction classes for these reactions were defined based on distinctive ele. inter. due to the complex characteristics of esters. Linear BEP correlations were established for each reaction class and validated by the high-level calculations, with deviations being less than 0.90 kcal/mol. The rate constants of some representative hydrogen abstraction reactions were calculated by using the BEP correlations and other approx. theories. These rate constants validate the BEP assumpn. of similar pre-exptl. factors for the reactions in the same group, and they are found to agree reasonably well with the available data in literature. Furthermore, improved predictn. to exptl. data were obtained by using an existing kinetic model of Me decanoate oxidation updated with the calculated rate constants The present BEP correlations are believed to provide effective solutions to some kinetic issues of real biodiesel combustion.

Combustion and Flame published new progress about Activation energy. 110-42-9 belongs to class esters-buliding-blocks, name is Methyl decanoate, and the molecular formula is C11H22O2, Application of Methyl decanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Atelge, M. R. published the artcileProduction of biodiesel and hydrogen by using a double-function heterogeneous catalyst derived from spent coffee grounds and its thermodynamic analysis, Recommanded Product: Methyl octanoate, the main research area is hydrogen biodiesel production heterogeneous catalyst spent coffee ground thermodn.

Biodiesel and hydrogen are promising liquid and gas energy source alternatives to satisfy fossil fuel demand. In this study, a heterogeneous catalyst, spent coffee grounds derived activated carbon supported, was synthesized using KOH as an activation agent. The highest iodine number was obtained at 600 °C carbonization temperature and the synthesized catalyst was subjected to the characterization and evaluated in terms of biodiesel and hydrogen production efficiencies. The optimal transesterification reaction parameters were determined as 3 wt% catalyst loading, 9:1 methanol-to-waste cooking oil molar ratio, 90 °C reaction temperature, and 120 min reaction time. Under optimal reaction conditions, the biodiesel yield was 91.57%. For hydrogen production, 100% conversion was observed in all cases. Among the exptl. conditions, the fastest reaction was obtained with the addition of 0.25 g superior catalyst with 2.5% of NaBH4 concentration at 30 °C reaction temperature Moreover, the chosen superior catalyst was successfully reused for five cycles to test the reusability of the catalyst. The catalyst performance was almost the same as of the first cycle after regeneration for both transesterification and dehydrogenation reactions. Addnl., the activation energy of the transesterification and methanolysis reactions was calculated as 19.15 and 15.48 kJ/mol, resp. In the thermodn. aspect, both reactions were endergonic and unspontaneous. Addnl., it can be concluded that the reactants were converted to the products very well due to the indication of entropy change.

Renewable Energy published new progress about Activation energy. 111-11-5 belongs to class esters-buliding-blocks, name is Methyl octanoate, and the molecular formula is C9H18O2, Recommanded Product: Methyl octanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics