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

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

• 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

Algae Biofuel Triacylglyceride Transesterification Optimization

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

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

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

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

Poly(oxime-ester) Vitrimers with Catalyst-Free Bond Exchange.

Vitrimers are network polymers that undergo associative bond exchange reactions in the condensed phase above a threshold temperature, dictated by the exchangeable bonds comprising the vitrimer. For vitrimers, chemistries reliant on poorly nucleophilic bond exchange partners (e.g., hydroxy-functionalized alkanes) or poorly electrophilic exchangeable bonds, catalysts are required to lower the threshold temperature, which is undesirable in that catalyst leaching or deactivation diminishes its influence over time and may compromise reuse. Here we show how to access catalyst-free bond exchange reactions in catalyst-dependent polyester vitrimers by obviating conventional ester bonds in favor of oxime-esters. Poly(oxime-ester) (POE) vitrimers are synthesized using thiol-ene click chemistry, affording high stretchability and malleability. POE vitrimers are readily recycled with little degradation of their initial mechanical properties, suggesting exciting opportunities for sustainable plastics

Konfirmatori faktor analisis kepuasan kerja dosen

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

Biodiesel production from olive-pomace oil of steam-treated alperujo

Recently interest has been revived in the use of plant-derived waste oils as renewable replacements for fossil diesel fuel. Olive–pomace oil (OPO) extracted from alperujo (by-product of processed olives for olive oil extraction), and produced it in considerable quantities throughout the Mediterranean countries, can be used for biodiesel production. A steam treatment of alperujo is being implemented in OPO extraction industry. This steam treatment improves the solid–liquid separation by centrifugation and facilitates the drying for further extraction of OPO. It has been verified that the steam treatment of this by-product also increases the concentration of OPO in the resulting treated solid, a key factor from an economic point of view. In the present work, crude OPO from steam-treated alperujo was found to be good source for producing biodiesel. Oil enrichment, acidity, biodiesel yield and fatty acid methyl ester composition were evaluated and compared with the results of the untreated samples. Yields and some general physicochemical properties of the quality of biodiesel were also compared to those obtained with other oils commonly used in biodiesel production. As for biodiesel yield no differences were observed. A transesterification process which included two steps was used (acid esterification followed by alkali transesterification). The maximum biodiesel yield was obtained using molar ratio methanol/triglycerides 6:1 in presence of sodium hydroxide at a concentration of 1% (w/w), reaction temperature 60 °C and reaction time 80 min. Under these conditions the process gave yields of about 95%, of the same order as other feedstock using similar production conditions.Junta de Andalucía (P06-AGR- 01906)Dr. Guillermo Rodríguez is grateful to the JAE-Doc Programme (CSIC) co-funded by European Social Fund (Operational Programme ESF 2007-2013

Experimental kinetic study of transesterification of ethyl acetate with methanol catalyzed by gel and macroporous acidic ion exchange resins

The reaction kinetics of the liquid-phase transesterification of ethyl acetate with methanol have been investigated over a series of commercially available ion-exchange resins. Two morphology types of cross-linked polymer resins have been considered, i.e., a gel type (Lewatit K1221) and a macroporous type (Lewatit K2640, Lewatit K2629 and Amberlyst 15). The effect of the swelling of the resin, the initial reactant molar ratio (1:1 – 10:1) and the temperature (303.15 – 333.15 K) on the reaction kinetics was experimentally assessed. Lewatit K1221, the gel-type resin, outperformed the macroporous-type resins, despite its similar number of sulfonic acid sites. The resin’s swelling behavior, which can be related to its degree of cross-linking with divinylbenzene, was identified as the key parameter to explain differences in acid site accessibility between the considered resins and, hence, the observed transesterification kinetics. A fundamental kinetic model, accounting for the chemical elementary steps as well as for the physical swelling due to solvent absorption, was constructed to quantitatively assess the experimental observations. According to this model (1) all active sites are occupied by methanol in protonated form, (2) the esters undergo a proton exchange with the protonated methanol and (3) the reaction occurs through an Eley-Rideal mechanism with the surface reaction of protonated ethyl acetate with methanol from the bulk as the rate-determining step. The kinetic model was able to adequately describe the entire experimental data set. An activation energy amounting to 49 kJ mol-1 was obtained, irrespective of the resin. Also the affinity of each of the resins for the esters was found to be similar. The differences in catalytic activity between the considered resins are found back in the values for the rate coefficients and, hence, can be brought into relation with the active site accessibility. The latter is a factor 3 to 4 higher for gel-type resins compared to macroporous-type resins. An independent experimental assessment of the resins’ swelling behavior confirmed the more pronounced swelling of the gel-type compared to the macroporous-type resins

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

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