Riccardo Tesser

Selective epoxidation of soybean oil with performic acid catalyzed by acidic ionic exchange resins

Abstract This work studied the epoxidation of soybean oil with aqueous hydrogen peroxide and formic acid, in the presence of acidic ionic exchange resins as catalysts. Amberlyst 16 was found to actively and highly selectively promote this reaction, and it also had good resistance to thermal and physical degradation. These properties also allow this resin to be used in continuous processes. A detailed study was carried out to determine the best operating conditions for the epoxidation of soybean oil in semibatch reactors, and preliminary epoxidation runs were performed in a continuous packed bed tubular reactor.

Biodiesel process intensification: the role of the liquid-liquid interface area in the achievement of a complete conversion in few seconds

Abstract Transesterification of vegetable oil with methanol, promoted by alkaline catalysts has been tested in many different reactors and surprisingly the reaction time, in some of these reactors, resulted very short, in the range of few seconds. In particular, by using static mixers, micro-reactors, oscillatory flow reactors, cavitational reactors, microwave reactors or centrifugal contactors, it is possible to obtain high biodiesel yields in a much shorter time than in stirred tank reactors. As the reaction occurs between two immiscible phases, a general conclusion could be that the higher the interface area the shorter the reaction time. In this paper, we will confirm this assumption because, by using a very efficient micro-mixer, followed by a void tube, very high conversions have been obtained in a few seconds of residence time. Another important observation is that passing from 1% to 2% b.w. of KOH catalyst concentration, a very high increase in the conversion is obtained. This means that the final conversion is not due to the chemical equilibrium but to the catalyst deactivation. For describing all the observed phenomena a new biphasic kinetic model based on a reliable mechanism has recently been developed and used here for quantitatively describing the performed runs.

New findings on soybean and methylester epoxidation with alumina as the catalyst

The activity of a commercial alumina, after a preliminary characterization, was investigated in epoxidation with soybean oil with aqueous hydrogen peroxide. Results show that the γ-alumina was an efficient catalyst. The role of the solvent in the epoxidation reaction in the presence of alumina was investigated. A “no-innocent” solvent role was demonstrated. Moreover, the optimization of the methyl oleate epoxidation reaction with alumina was eventually valuated, varying the type of the solvent and concentration of hydrogen peroxide in order to obtain a product with commercial features.

Niobium Based Catalysts for Methyl Oleate Epoxidation Reaction

In this paper, nine different catalysts have been used for the epoxidation of methyl oleate with hydrogen peroxide as oxidant. The prepared catalysts were mostly based on supported systems niobia–alumina and niobia–silica. Experimental runs were carried out in a lab-scale reactor, keeping constant operating parameters such as reaction temperature (80u2009°C) and time (5xa0h), and molar ratio between oxidant and methyl oleate (equal to 4). Runs aimed at the quantitative evaluation of system conversion, yield and selectivity. Nb2O5/SiO2 were found to be active in epoxidation reaction, in particular the catalyst with intermediate niobia loading (6% w/w) showed very high conversion (77%) even if with a very low selectivity to epoxides (30%). Instead, regarding the system based on Nb2O5/Al2O3, both better activity and selectivity were reached. In particular, the material containing 12% of Niobia yielded the highest values for conversion (83%) and selectivity (89%). The results have been critically discussed through the outcomes of a deep characterization of the catalytic materials, carried out through porosimetric, X-ray diffraction, ultra violet and visible diffuse reflection, and Raman microscopy analyses. The discussion highlighted the more relevant parameters able to influence the activity of niobia-based catalysts in the methylesters epoxidation.

On the Importance of Choosing the Best Minimization Algorithm for the Determination of Ternary Diffusion Coefficients by the Taylor Dispersion Method

Taylor dispersion method is a common technique for the determination of diffusion coefficients in the case of multicomponent systems. One of the main problems related to the parameter estimation analysis of the collected results is the choice of the best minimization algorithm that allows finding the real minimum of the objective function. Usually, researchers use the Levenberg–Marquardt algorithm, averaging the parameters obtained by different estimation analyses. In this paper, some nonlinear minimization algorithms included in MATLAB R2016a have been tested, and the results are compared in terms of best fit on the experimental data collected for sodium dodecyl sulfate (SDS) + sodium octanoate (SOC) + water system.

Facind the hazards of biphasic, unstable, highly exothermic process: the case of epoxidation of vegetable oils

Facing the Hazard of Biphasic, Unstable, Highly Exothermic Process: the Case of Epoxidation of Vegetable Oils Ernesto Salzano*, Vincenzo Russo, Riccardo Tesser, Martino Di Serio Dipartimento di Ingegneria Civile, Chimica, Ambientale e dei Materiali, Alma Mater Studiorum Università di Bologna, Via Terracini 28, 40131 Bologna (IT). Dipartimento di Chimica, Università di Napoli “Federico II” – Complesso Universitario Monte S. Angelo, Via Cintia 4, I80126 Napoli (IT) ernesto.salzano@irc.cnr.it