Thermochemical data of the oleic acid esterification reaction: A quantum mechanics approach

Silva, Marcos V.D.; Hori, Carla Eponina; Reis, Miria Hespanhol Miranda

doi:10.1016/j.fluid.2015.07.050

Cited by 6 publications

(11 citation statements)

References 28 publications

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“…Δc p,L /R 2 ethyl oleate , Δc p,L / R 2 propyl oleate ). [7,[11][12][13][14] The pronounced differences in photoesterification efficiencies observed for the three alcohols may also be caused by RI (refractive index) differences, with higher RIs lowering the catalyst's capacity, as described in section 2.1.1 (RI MeOH : 1.3165, RI EtOH : 1.3464, and RI n-PrOH : 1.3704 [35] ).…”

Section: Chemphotochemmentioning

confidence: 99%

“…This observation is in line with previous reports for other catalyst systems. [11,45,55] Methanol has a partial charge greater than ethanol or propanol and thus, it is a better electron donor for oleic acid esterification. [11] Consequently, the energy required to produce ethyl oleate or n-propyl oleate is higher than that of methyl oleate (ΔH°m ethyl oleate !…”

Section: Chemphotochemmentioning

confidence: 99%

“…[11,45,55] Methanol has a partial charge greater than ethanol or propanol and thus, it is a better electron donor for oleic acid esterification. [11] Consequently, the energy required to produce ethyl oleate or n-propyl oleate is higher than that of methyl oleate (ΔH°m ethyl oleate ! ΔH°e thyl oleate , ΔH°n -propyl oleate and Δc p,L /R 2 methyl oleate !…”

Section: Chemphotochemmentioning

confidence: 99%

“…The esterification reaction of free fatty acid occurs preferably in the presence of short-chain alcohols (methanol, ethanol or propanol) and requires a catalyst. [7,[11][12][13][14] The most common catalysts are strong acids such as sulfuric acid. However, the use of strong acids causes problems such as equipment corrosion, the necessary removal of the catalyst, and the large amounts of waste generated.…”

Section: Introductionmentioning

confidence: 99%

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Methyl Oleate Synthesis by TiO₂ Photocatalytic Esterification of Oleic Acid: Optimisation by Response Surface Quadratic Methodology, Reaction Kinetics and Thermodynamics

et al. 2022

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Methyl oleate, an example of a FAME (fatty acid methyl ester), was produced by oleic acid (OA) photoesterification with TiO2 and UVA light. Different parameters were evaluated and optimised: catalyst pretreatment, temperature (25–65 °C), catalyst loading (1–30 % w/wOA) and oleic acid : alcohol molar ratio (1 : 3–1 : 55). Response surface quadratic methodology obtained by central composite rotational design (RSM‐CCRD) was used to evaluate the main operational conditions of the photoesterification process. A high conversion of 98 % (±0.8) at 55 °C, 20 % TiO2 (w/wOA), and 1(OA) : 55(methanol) molar ratio was achieved. The photoesterification mechanism is furthermore proposed. The Langmuir‐Hinshelwood kinetic model considered the forward and backward reaction as first‐order fits with the best accuracy (R2 of 0.997). The thermodynamic results (ΔG338.15K=−20.75 kJ/mol, ΔH=13.75 kJ/mol, and ΔS=0.47 kJ/mol.K) indicate that the operating conditions are important, both to supply the energy requirement of the reaction, but also to increase the miscibility of the reactants.

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Section: Chemphotochemmentioning

confidence: 99%

Section: Chemphotochemmentioning

confidence: 99%

Section: Chemphotochemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Methyl Oleate Synthesis by TiO₂ Photocatalytic Esterification of Oleic Acid: Optimisation by Response Surface Quadratic Methodology, Reaction Kinetics and Thermodynamics

et al. 2022

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“…The most significant gap of this process is the reactants' miscibility. It can be overcome by using high alcohol content and temperatures higher than 50ºC (Bonet 2014;Silva et al 2015) or increasing the interfacial surface (i.e., ultrasound, supercritical conditions, co-solvents, and microscale reactors).…”

Section: Literature Review Biodiesel Synthesis In Microreactorsmentioning

confidence: 99%

Are Microreactors the Future of Biodiesel Synthesis?

Welter¹,

Silva²,

Souza³

et al. 2022

Preprint

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Microfluidic devices or microdevices refer to systems with a characteristic length in the micrometer range. Systems in this size allow handling small quantities of reagents and samples, with reduced residence time, better control of chemical species concentration, high heat and mass transfers, and high surface/volume ratio. These characteristics led to the application of these microdevices in several areas, such as biological systems, energy, liquid-liquid extraction, food, agricultural sectors, pharmaceuticals, flow chemistry, microreactors, and biodiesel synthesis. Microreactors are devices that have interconnected microchannels, in which small amounts of reagents are manipulated and react for a certain period of time. The traditional characteristics of microreactors are less quantities of reagents and samples, high surface area in relation to volume (10000 m2 m-3), reduction of resistance to heat and mass transfer, reduced reaction times, and narrower residence time distributions. In recent years, several studies have been carried out on biodiesel production in microreactors that explore the influence of operating conditions, mixing and reaction yield, numbering, and especially the microdevices design. Despite all the advantages of microreactors, the literature shows that there are only a few applications on an industrial scale. Two main reasons that hinder the adoption of this technology are the scale-up to a large enough volume to deliver the necessary production capacity and the costs related to industrial manufacturing microreactors. It is often stated that large-scale production of microreactors can be easily achieved by numbering-up. However, researches show that an incredibly high number of microdevices would be needed, which results in a technical unfeasibility and a strong impact on the construction costs of the industrial system. The present review aims to show whether microreactors can replace conventional biodiesel production processes and how this replacement technology could be carried out. The current chapter was divided into the following sections: Introduction, Synthesis and Purification of Biodiesel in Microreactors, Fundamentals of CFD, and Fundamentals of Scale-up. Finally, conclusions and future perspectives are exposed.

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Biodiesel Production by Heterogeneous Catalysis and Eco‐friendly Routes

et al. 2023

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Biodiesel is produced on a large scale as an ecofriendly substitute and additive to fossil fuels. Catalytic homogeneous processes using strong acids, alkalis, and natural oils have been realized in industry. However, these traditional methods have several disadvantages, such as the generation of large volumes of waste, high water and reagent needs, use of hazardous reagents, high operation costs, and utilization of valuable feedstocks and catalysis, respec-tively. Different solutions have subsequently been investigated, such as cheap alternative feedstocks, co-solvents and catalysts, sustainable operational conditions, advanced reactor designs and scales, and advantageous pre-and post-reaction treatments. This review explores and analyzes the main aspects of current biodiesel technologies and opportunities. It also describes some advanced improvement strategies.

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Thermochemical data of the oleic acid esterification reaction: A quantum mechanics approach

Cited by 6 publications

References 28 publications

Methyl Oleate Synthesis by TiO₂ Photocatalytic Esterification of Oleic Acid: Optimisation by Response Surface Quadratic Methodology, Reaction Kinetics and Thermodynamics

Methyl Oleate Synthesis by TiO₂ Photocatalytic Esterification of Oleic Acid: Optimisation by Response Surface Quadratic Methodology, Reaction Kinetics and Thermodynamics

Are Microreactors the Future of Biodiesel Synthesis?

Biodiesel Production by Heterogeneous Catalysis and Eco‐friendly Routes

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Thermochemical data of the oleic acid esterification reaction: A quantum mechanics approach

Cited by 6 publications

References 28 publications

Methyl Oleate Synthesis by TiO2 Photocatalytic Esterification of Oleic Acid: Optimisation by Response Surface Quadratic Methodology, Reaction Kinetics and Thermodynamics

Methyl Oleate Synthesis by TiO2 Photocatalytic Esterification of Oleic Acid: Optimisation by Response Surface Quadratic Methodology, Reaction Kinetics and Thermodynamics

Are Microreactors the Future of Biodiesel Synthesis?

Biodiesel Production by Heterogeneous Catalysis and Eco‐friendly Routes

Contact Info

Product

Resources

About

Methyl Oleate Synthesis by TiO₂ Photocatalytic Esterification of Oleic Acid: Optimisation by Response Surface Quadratic Methodology, Reaction Kinetics and Thermodynamics

Methyl Oleate Synthesis by TiO₂ Photocatalytic Esterification of Oleic Acid: Optimisation by Response Surface Quadratic Methodology, Reaction Kinetics and Thermodynamics