Transesterification Of Rapeseed Oil Research Articles

Transesterification of rapeseed oil with methanol using CaO and active carbon powders encapsulated microcapsule under the light irradiation

Transesterification of rapeseed oil with methanol to fatty acid methyl ester (FAME) was conducted using microcapsules loaded with CaO catalyst and active carbon powder under the light irradiation. About 80% of FAME yield was obtained after 6h of reaction with keeping the temperature of reactant mixture (rapeseed oil, methanol, and tetrahydrofuran (THF)) at 308K. This is probably because encapsulated active carbon powder in the microcapsule absorbed the near-infrared and visible ranges of irradiated light, and then transferred the heat inside the microcapsule which leads to higher temperature of inside microcapsule than that of reaction media/bulk. The results of ICP analyses for both FAME and glycerol phases showed that the amount of leached Ca species was significantly reduced due to lower reaction temperature and microcapsule usage. XRD patterns of tested catalysts indicated that the formation of calcium diglyceroxide phase during the transesterification was remarkably retarded for the case of CaO-active carbon-loaded microcapsule in contrast to a conventional process with CaO powder. This light-driven transesterification of rapeseed oil with methanol using catalyst-loaded microcapsule is promising system owing to high FAME yield and low amount of Ca species leaching into FAME phase.

Monoglycerides reduction in rapeseed oil transesterification for production of high quality biodiesel

Monoglycerides are intermediate by products in rapeseed oil transesterification. If they are present in the bio-fuel and the bio-fuel is used in vehicles, then they can form crystal at cold climate and block fuel injection system of the vehicles. To solve this problem kinetic study of transesterification of rapeseed oil has been carried out in this study. The process variables such as reaction time, temperature, agitation speed and molar ratio of methanol to oil have been optimised to achieve a reduced level of monoglycerides formation in a batch reactor. These information have been integrated into flow through industrial scale transesterification process. Industrial processes demonstrated a steady performance with reduced level of monoglycerides. Monoglycerides level have been reduced to 0.27% (w/w) using 9:1 molar ratio of methanol to oil in about 40 min reaction time. KOH was used as a catalyst to influence transesterification. Results from this study will be helpful to reduce monoglycerides in the industrial scale transesterification process.

Fed-Batch Feeding Strategies for Enzymatic Biodiesel Production

In this work a kinetic model for the enzymatic transesterification of rapeseed oil using a solubilised lipase (Callera Trans L-Thermomyces lanuginosus) was developed from first principles. The model is based on a Ping-Pong Bi-Bi mechanism, with methanol inhibition, along with consideration of the differences in the interfacial and bulk concentrations of the enzyme. The model is then used to evaluate various feeding strategies to improve the enzymatic biodiesel production. The feeding strategies investigated, gave insight into how the methanol should be fed to potentially mitigate enzyme deactivation while improving the biodiesel yield. The best experimental results gave a yield of 703.76 g FAME L-1 and a reactor productivity of 28.12 g FAME L-1 h-1. In comparison, to reach the same yield, the optimised two step feeding strategy took 6.25 hours less, which equates to an increase the reactor productivity of 36.9 %.

Supercritical transesterification: Impact of different types of alcohol on biodiesel yield and LCA results

A series of experiments with transesterification of rapeseed oil in supercritical methanol and supercritical ethanol was carried out in a batch reactor at various reaction temperatures (250–350°C), working pressure (8–12MPa), reaction time (7, 15 and 30min), and at a constant 42:1 alcohol to oil molar ratio. The effect of alcohol, temperature, pressure and reaction time on biodiesel yield was investigated using linear multiple regression models. In the observed range, temperature has the highest impact on yields, followed by reaction time and pressure. The relative importance of time and pressure in explaining yields is higher in the case of transesterification in supercritical ethanol. The results of environmental life cycle assessment have revealed that contrary to general belief the usage of ethanol instead of methanol cannot improve the sustainability and renewability of the transesterification process significantly.

Novel solid acid with both Brønsted and Lewis acid sites for biodiesel synthesis

The solid acid with both Bronsted and Lewis acid sites has been synthesized from resorcinol-formaldehyde (RF) resin, hydroxyethylsulfonic acid and copper hydroxyethylsulfonate. The solid acid was applied to catalyze the transesterification of rapeseed oil. The results showed that the novel solid acid was very efficient for the biodiesel synthesis with the yield over 99% even for the rapeseed oil with high water content and both the free fatty acid and triglyceride could be efficiently transformed to the biodiesel products. The regular sphere structure, low cost, high acidity and catalytic activities gave the solid acid great potential for green chemical processes.

Kinetics of rapeseed oil transesterification over a heterogeneous barium-aluminum oxide catalyst with the methanol pressure taken into account

Use of heterogeneous catalysts in the synthesis of biodiesel from vegetable lipids via transesterification with alcohols has certain advantages over use of homogeneous catalysts. Commercialization of this process needs investigation of its kinetics. Here, we report, for the first time, the kinetics of transesterification of rapeseed oil with gaseous methanol over a heterogeneous catalyst with methanol partial pressure taken into account. Experiments have been carried out in a flow reactor with a fixed bed of a barium-aluminum oxide catalyst at 200°C and a methanol pressure of 0.1–2.5 MPa. Experimental data have been processed in terms of a simplified kinetic model involving one irreversible second-order reaction (first-order reaction with respect to both oil and methanol). Service life tests have been carried out for the catalyst calcined at 700°C.

Activation of Commercial CaO for Biodiesel Production from Rapeseed Oil Using a Novel Deep Eutectic Solvent

A deep eutectic solvent (DES) consisting of choline chloride and glycerol (1:2 molar ratio) was prepared and used as the solvent in CaO-catalyzed transesterification of rapeseed oil to produce biodiesel. In addition to its solvent role, DES activated commercial CaO to be a catalyst for the transesterification reaction. The yield of fatty acid methyl ester (FAME) with the addition of DES reached 91.9%, while the FAME yield with no DES was only 4.0%. The commercial CaO samples before and after reaction were characterized by Powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and Scanning Electronic Microscopy (SEM). These measurements indicate that the surface of commercial CaO is typically covered by a layer of CaCO3 and Ca(OH)2 which inhibits the activity of CaO, while the addition of DES can eliminate this inhibiting layer leading to CaO activation.

Aspects of potassium leaching in the heterogeneously catalyzed transesterification of rapeseed oil

The main aim of the work is to define the critical aspects of the stability of solid K-based catalysts (K-CaO, K-MgO and K-Al2O3) in the transesterification of rapeseed oil by methanol. High activity of these catalysts is often reported, but their stability is recently a matter for discussion. The attention is focused on (i) the explanation of the reason of potassium leaching from the solid K-based catalysts into the liquid phase during the reaction, (ii) a description of the role of leached K-species in the reaction and (iii) the suggestion of the mechanism of the potassium leaching from the solid K-based catalysts. It was found that the leaching of K-species is caused by glycerol that is formed during the reaction. The mechanism of K-leaching from the solid catalyst was suggested. The strength of alcohols to attack the K-species on solid catalysts increased with the number of alcohol groups and their mutual distances and has following order: glycerol>1,3-propanediol>1,2-propanediol>ethylene glycol>methanol.

Investigation of the influence of the catalyst in the process of producing biodiesel using supercritical methanol

The article discusses various ways to produce biodiesel fuel: in the presence of homogeneous catalysts, in the presence of heterogeneous catalysts, in supercritical methanol. There was experimentally confirmed that the process of obtaining methyl ethers of fatty acids (FAME) in the supercritical methanol on the selectivity, on replacement of the target product and process stability in time can compete with catalytic methods. There was studied the efficiency of the catalyst at the transesterification of rapeseed oil in supercritical methanol under the following process parameters: temperature of 300°C, the pressure of 300 atmospheres, the volume fraction of oil 0,5. There was evaluated that during the first hours after the filing of the reagents into the reactor in the presence of a catalyst TiO2/Ti concentration FAME in the oil layer of the reaction products is more than in not catalysed reaction. However, approximately one hour after the beginning of the process of catalytic activity was sharply reduced, and the output of the FAME becomes less, than without a catalyst. By means of mass-spectral analysis of the product, extracted from the surface of the catalyst, it is discovered a tumor in the process of interesterification low-volatile and poorly soluble substances, blocking the active centres of the catalyst. In addition, the reduction in catalytic activity became the result of partial destruction of the surface layer of TiO2. It is established, that the washing of the spent catalyst mixture of solvents with the subsequent heating at 350°C allows largely to restore the activity of the catalyst.

In situ preparation of K2CO3 supported Kraft lignin activated carbon as solid base catalyst for biodiesel production

In this study, the catalysts K2CO3 supported Kraft lignin activated carbon (K2CO3/KLC) were prepared in situ by simply mixing K2CO3 with technical Kraft lignin (KL) and subsequently activating at 800°C for 2h under N2 flow. The precursor and catalysts were characterized by thermal gravity analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) surface area. The catalytic performance of prepared catalysts was evaluated by transesterification of rapeseed oil with methanol. The effects of various parameters on biodiesel yield were investigated. The biodiesel yield of 99.6% was achieved by using the catalyst prepared by 0.6 of K2CO3/KL mass ratio and activation at 800°C, under the transesterification condition of 65°C, 2h, methanol to rapeseed oil molar ratio of 15:1 and 3.0wt.% catalyst (relative to the weight of rapeseed oil). The solid catalyst can be reused for 4 times and biodiesel yield remained over 82.1% for the fourth time.

The exploitation and environmental characteristics of diesel fuel containing rapeseed butyl esters

In an effort to consume fewer non-renewable resources and use primarily raw materials of biological origin in the production of biofuel, biomass-derived biobutanol can be used for transesterification of rapeseed oil. The study investigates the physical and chemical characteristics of rapeseed oil butyl esters (RBE) and 10%, 20% and 30% RBE-diesel composites. Characteristics of RBE and their composites with conventional diesel (D) are a little different from rapeseed oil methyl esters (RME) and their composites with D, while their basic characteristics comply with the requirements of European Standard EN 14214. Comparative tests in 4-stroke 4-cylinder 1Z type diesel engine of Audi-80 using 10-30% RBE and 10-30% RME compounds as fuels have been performed, and the results indicate that the biologically derived additives improved the energy characteristics of the engine but increased the fuel consumption compared to pure diesel. Increasing the bio-component concentration up to 30% in diesel and biodiesel fuel (RME and RBE) mixtures leads to complex improvements in the environmental impact compared to pure diesel; however, in the case of mixtures with RBE, slightly higher concentrations of carbon dioxide (CO2), hydrocarbons (HC) and nitrogen oxides (NOx) were observed in engine exhaust gases compared to RME and D mixtures of analogical composition.

The Effect of Thermal Pre-Treatment on Structure, Composition, Basicity and Catalytic Activity of Mg/Al Mixed Oxides

The goal of this work is to study the effect of thermal pre-treatment of Mg/Al mixed oxides (450–1,050 °C) on their structure, basicity and catalytic activity in transesterification of rapeseed oil. The catalytic activity of Mg/Al catalysts was shown to depend not only on the amount of basic sites, but also on crystallite size of MgO, specific surface area and population of medium/strong basic sites. Moreover, high stability of Mg/Al-550 was established by re-using the catalyst four times. It was associated with negligible magnesium leaching from the solid catalyst to liquid phases.

Transesterification of rapeseed oil for biodiesel production in trickle-bed reactors packed with heterogeneous Ca/Al composite oxide-based alkaline catalyst

A conventional trickle bed reactor and its modified type both packed with Ca/Al composite oxide-based alkaline catalysts were studied for biodiesel production by transesterification of rapeseed oil and methanol. The effects of the methanol usage and oil flow rate on the FAME yield were investigated under the normal pressure and methanol boiling state. The oil flow rate had a significant effect on the FAME yield for the both reactors. The modified trickle bed reactor kept over 94.5% FAME yield under 0.6mL/min oil flow rate and 91mL catalyst bed volume, showing a much higher conversion and operational stability than the conventional type. With the modified trickle bed reactor, both transesterification and methanol separation could be performed simultaneously, and glycerin and methyl esters were separated additionally by gravity separation.

Simultaneous synthesis of biodiesel and zinc oxide nanoparticles using supercritical methanol

Biodiesel and zinc oxide nanoparticles were synthesized simultaneously using supercritical methanol. Zinc nitrate was used as the source of zinc for the formation of the zinc oxide nanoparticles, which acted as a catalyst during the transesterification of rapeseed oil. In addition, the in situ formed zinc oxide nanoparticles led to a reduction in the reaction temperature and time. The fatty acid methyl ester (FAME) yields in the various biodiesels synthesized were determined using gas chromatography (GC). The zinc oxide nanoparticles formed were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) spectroscopy. The results of these analyses confirmed the formation of surface-modified zinc oxide nanoparticles of sizes smaller than those obtained using conventional techniques. This newly developed method provides an economical advantage since it results in the lowering of the operational temperature and the production of zinc oxide as an additional byproduct.

Microcapsule with a heterogeneous catalyst for the methanolysis of rapeseed oil

This study has demonstrated that microcapsules can be used as a microreactor for the transesterification of rapeseed oil with calcium oxide (CaO) base catalyst. CaO-loaded microcapsules were prepared by coextrusion technique, and the transesterification reaction was carried out by adding methanol into the prepared microcapsules and oil in a batch-type reactor. Results showed that the microcapsules system could promote the transesterification and hinder the dissolution of the catalyst, in contrast to a biodiesel production with CaO particles. The optimal conditions for methanol to oil molar ratio, catalyst content in the microcapsules and reaction temperature were found to be 8:1, 20wt.%, and 65°C, respectively. The results of reusability tests showed that CaO-loaded microcapsules could be successfully reused for three times without loss of the catalytic activity. It was concluded from these results that microcapsules have the potential to improve the performance of solid base catalyst for biodiesel production.

Effect of calcination temperature on the activity of solid Ca/Al composite oxide-based alkaline catalyst for biodiesel production

A solid Ca/Al composite oxide-based alkaline catalyst containing Ca12Al14O33 and CaO was prepared by chemical synthesis and thermal activation from sodium aluminate solution and calcium hydroxide emulsion. The effect of calcination temperatures ranging from 120°C to 1000°C on activity of the catalyst was investigated. The catalyst calcined at 600°C showed the highest activity with >94% yield of fatty acid methyl esters (i.e. biodiesel) when applied to the transesterification of rapeseed oil at a methanol:oil molar ratio of 15:1 at 65°C for 3h. Structure and properties of the catalyst were studied and the characterizations with XRD, TGA, FTIR, BET, and SEM demonstrated that the performance of the catalyst was closely related to its specific surface area and crystalline structure. In particular, the generation of crystalline Ca12Al14O33 improved the catalytic activity due its synergistic effect with CaO.

Synthesis of magnetic calcium oxide hollow fiber catalyst for the production of biodiesel

Magnetic recycled calcium oxide hollow fibers were successfully prepared for the transesterification of rapeseed oil with methanol to produce biodiesel. The hollow fiber catalyst prepared from different molar ratios of metal ions, various annealing atmospheres and annealing temperatures were characterized by scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, vibrating sample magnetometer, and Brunauer–Emmer–Teller surface area measurements. Under optimum conditions (Ca2+:Fe3+ = 1:2, reducing atmosphere annealing at 1000°C), magnetic calcium oxide hollow fibers with average pore size around 6.3061 nm, the surface area of 15.28 m−1, and saturation magnetization of 136.564 Am2 kg−1 were produced by organic gel‐thermal decomposition. Then, their catalytic activities were studied, and 95.7% biodiesel yield was achieved. The catalyst was separated by a magnetic field and recycled 20 times, and 85.2% biodiesel yield was still obtained. Magnetic calcium oxide hollow fibers are active, stable, and easily separated green catalysts that may find practical uses in biodiesel industry. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 1255–1261, 2013

Cogeneration of biodiesel and nontoxic rapeseed meal from rapeseed through in-situ alkaline transesterification

In-situ alkaline transesterification of rapeseed oil with methanol for the production of biodiesel and nontoxic rapeseed meal was carried out. Water removal from milled rapeseed by methanol washing was more effective than vacuum drying. The conversion rate of rapeseed oil into FAME was 92%, FAME mass was 8.81g, glucosinolates content in remaining rapeseed meal was 0.12% by methanol washing, while by vacuum drying the values were 46%, 4.44g, 0.58%, respectively. In the presence of 0.10mol/L NaOH in methanol, with methanol/oil molar ratio of 180:1 and a 3h reaction at 40°C, a conversion rate of 98% was achieved, and the glucosinolates content was reduce to 0.07%, a value which below the GB/T 22514-2008 standard in China. Thus the rapeseed meal can be used as a source of protein in animal feed. The FAME prepared through in-situ alkaline transesterification met the ASTM specifications for biodiesel.

Environment-friendly biodiesel production by transesterification of rapeseed oil: effect of reaction parameters

Abstract The huge energy demand in the industrialized world and the pollution problems caused due to the worldwide consumption of fossil fuels has made it necessary to develop alternative sources of energy. It is estimated that pure biodiesel provides over 90% reduction in unburned hydrocarbons and 75–90% reduction in aromatic hydrocarbons. This results in almost total reduction in sulphur dioxide (which causes acid rains), 40–60% reduction in soot particles, 80% and 10– 15% reduction in carbon dioxide and carbon monoxide emissions respectively. Reduction of poly-aromatic hydrocarbons is extremely important as many of these hydrocarbons are cancer causing and ozone-forming compounds. Biodiesel does not interfere with the carbon cycle or cause climate change (vegetables from which oils are extracted for biodiesel production remove carbon dioxide from the atmosphere to grow). Due to the global drive towards renewable, non-toxic and environmentally acceptable products the ability of the commercial lipolytic ...

Transesterification of rapeseed oil in supercritical methanol in a flow reactor

Transesterification reactions of rapeseed oil in supercritical methanol in a flow reactor over a wide range of variation of the methanol/oil ratio, pressure, and contact time are studied. Conditions ensuring selectivity and a high degree of rapeseed oil conversion are found. Experiments to study this reaction in the presence of zeolite heterogeneous catalyst are performed.