48,447 research outputs found

    Methyl esters selectivity of transesterification reaction with homogenous alkaline catalyst to produce biodiesel in batch, plug flow, and continuous stirred tank reactors

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    Selectivity concept is essential in establishing the best operating conditions for attaining maximum production of the desired product. For complex reaction such as biodiesel fuel synthesis, kinetic studies of transesterification reaction have revealed the mechanism of the reaction and rate constants. The objectives of this research are to develop the kinetic parameters for determination of methyl esters and glycerol selectivity, evaluate the significance of the reverse reaction in transesterification reaction, and examine the influence of reaction characteristics (reaction temperature, methanol to oil molar ratio, and the amount of catalyst) on selectivity. For this study, published reaction rate constants of transesterification reaction were used to develop mathematical expressions for selectivities. In order to examine the base case and reversible transesterification, two calculation schemes (Case 1 and Case 2) were established. An enhanced selectivity was found in the base case of transesterification reaction. The selectivity was greatly improved at optimum reaction temperature (60 C), molar ratio (9 : 1), catalyst concentration (1.5 wt.%), and low free fatty acid feedstock. Further research might explore the application of selectivity for specifying reactor configurations

    The Transesterification of Hickory Nuts into Biodiesel Fuel

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    • Biodiesel fuels can be produced from a fat and an alcohol via transesterification • Hickory nuts have a high fat content (~60 % by weight) • Can nuts from shagbark hickory (Carya ovata) be used to produce a biodiesel fuel using existing acidcatalyzed transesterification methods

    Intensified processes for FAME production from waste cooking oil: a technological review

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    This article reviews the intensification of fatty acid methyl esters (FAME) production from waste cooking oil (WCO) using innovative process equipment. In particular, it addresses the intensification of WCO feedstock transformation by transesterification, esterification and hydrolysis reactions. It also discusses catalyst choice and product separation. FAME production can be intensified via the use of a number of process equipment types, including as cavitational reactors, oscillatory baffled reactors, microwave reactors, reactive distillation, static mixers and microstructured reactors. Furthermore, continuous flow equipment that integrate both reaction and separation steps appear to be the best means for intensifying FAME production. Heterogeneous catalysts have also shown to provide attractive results in terms of reaction performance in certain equipment, such as microwave reactors and reactive distillation

    On-line monitoring of the transesterification reaction between triglycerides and ethanol using near infrared spectroscopy combined with gas chromatography

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    Many analytical procedures have been developed to determine the composition of reaction mixtures during transesterification of vegetable oils with alcohols. However, despite their accuracy, these methods are time consuming and cannot be easily used for on-line monitoring. In this work, a fast analytical method was developed to on-line monitor the transesterification reaction of high oleic sunflower oil with ethanol using Near InfraRed spectroscopy and a multivariate approach. The reactions were monitored through sequential scans of the reaction medium with a probe in a one-liter batch reactor without collecting and preparing samples. To calibrate the NIR analytical method, gas chromatography-flame ionization detection was used as a reference method. The method was validated by studying the kinetics of the EtONa-catalyzed transesterification reaction. Activation energy (51.0 kJ/mol) was also determined by considering a pseudo second order kinetics model

    Konfirmatori faktor analisis kepuasan kerja dosen

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    The University is one of the places to improve the quality of human resources. The development of education at the University of Batam city in particular has involved many parties, namely professors, the University, the community and other educational organizations. Job satisfaction in University lecturer becomes important to note. The lack of research on job satisfaction in University environment and the existing research is usually done in the industrial sector alone, so this study needs to be done at University. The object in this study to confirm the item indicators of job satisfaction lecturer. Data were collected using a questionnaire involves a number of 392 lecturers in Batam City University namely Putera Batam University, Batam University, and University of Riau Islands. Data were analyzed using SEM study of Amos. Results of the study found that, item 7 item confirming the satisfaction indicators indicators that can measure satisfaction with the Good of Fit is acceptable. The acquired results of the study can be used as a reference for the purposes of institutions, academics, and practitioners in making standards and evauasi job satisfaction. In addition, on behalf of the University needs to consider item indicators of satisfaction and need to also pay attention to other factors beyond the performed studies such as demographic factors, management and others

    ZnO/ionic liquid catalyzed biodiesel production from renewable and waste lipids as feedstocks

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    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 thermodynamic parameters of activation (∆G‡ and ∆H‡) are also studied for transesterification reaction

    Modification of chiral dimethyl tartrate through transesterification : immobilisation on POSS and enantioselectivity reversion in Sharpless asymmetric epoxidation

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    Modification of dimethyl tartrate has been investigated through transesterification with aminoalcohols to provide reactive functionalities for the covalent bonding of chiral tartrate to polyhedral oligomeric silsesquioxanes. The transesterification of dimethyl tartrate has been widely studied by means of using different catalytic systems and reaction conditions. Through the proper selection of both, the catalytic system and the reaction conditions, it is possible to achieve the mono- or the bis-substituted tartrate derivative as sole products. All the intermediate chiral tartrate-derived ligands were successfully used in the homogeneous enantioselective epoxidation of allylic alcohols providing moderate enantiomeric excess over the products. Attached amine groups have been used to support the modified tartrate ligands onto a haloaryl-functionalized silsesquioxane moiety. This final chiral tartrate ligand displays enantioselectivity reversion in the asymmetric epoxidation of allylic alcohols with regards to the starting dimethyl tartrate ligand, having both molecules them the same chiral sign. However, the POSS-containing ligand can be easily recovered in almost quantitative yield and reused in asymmetric epoxidation reactions. In addition, recovered silsesquioxane-pendant ligand, though displaying decreasing catalytic activity in recycling epoxidation tests, showed very stable enantioselective behavior

    Esterification of Free Fatty Acids with Glycerol within the Biodiesel Production Framework

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    Companies in the field of the collection and treatment of waste cooking oils (WCO) for subsequent biodiesel production usually have to cope with high acidity oils, which cannot be directly transformed into fatty acid methyl esters due to soap production. Since glycerine is the main byproduct of biodiesel production, these high acidity oils could be esterified with the glycerine surplus to transform the free fatty acids (FFA) into triglycerides before performing the transesterification. In this work, commercial glycerol was esterified with commercial fatty acids and commercial fatty acid/lampante olive oil mixtures over tin (II) chloride. In the first set of experiments, the esterification of linoleic acid with glycerol excess from 20 to 80% molar over the stoichiometric was performed. From 20% glycerol excess, there was no improvement in FFA reduction. Using 20% glycerol excess, the performance of a biochar obtained from heavy metal-contaminated plant roots was compared to that of SnCl2. Then, the effect of the initial FFA content was assessed using different oleic acid/lampante olive oil mixtures. The results illustrated that glycerolysis was impeded at initial FFA contents lower than 10%. Finally, the glycerolysis of a WCO with 9.94% FFA was assayed, without success

    Algae Biofuel Triacylglyceride Transesterification Optimization

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    Algae biofuels may hold the key to solving the problem of fossil fuel consumption by being comparable in content, renewable, and carbon-neutral. Many biofuel researchers and corporations have undertaken to increase the production rate or capacity of triacylglycerides (TAG), the fat precursor to biodiesel fuel produced by algae, in algae cultures and published articles documenting their findings. This research is devoted to evaluating the effect of water that may be present in samples on the conversion efficiency of TAG into fatty acid methyl esters (FAME), commonly referred to as biodiesel. Therefore, that efficiency was studied to find the water content which optimizes the yield and determine if further drying of algae was necessary as an additional step in sample preparation. The results showed that the water content typically present in lyophilized algae samples is not sufficient to appreciably inhibit the reaction efficiency and necessitate extensive drying as a sample preparation step prior to transesterification
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