Rosa Turco

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.

Glycerol chlorination in a gas-liquid semibatch reactor：New catalysts for chlorohydrin production

Glycerol from biodiesel production can be an important industrial feedstock for chemical commodities as it can be used in the food, cosmetic, pharmaceutical and tobacco industries. However, crude glycerol derived from biodiesel production has a low value because of impurities. The purification of this glycerol into a high grade involves high costs and is not economically feasible for small and medium size plants. The glycerol conversion into chlorohydrins was studied using new homogeneous catalysts and hydrochloric acid as chlorination agent. This is an interesting alternative route to epichlorohydrin and then to epoxy resins. The behavior of two series of homologous catalysts, glycolic acid series (glycolic acid, di-glycolic acid and thio-glycolic acid) and amminoacid series (glutamic acid, aspartic acid and cysteine), were investigated for their activity and selectivity. Glycolic acids were more active than amminoacids. The pKa values had a strong influence on selectivity (mono-chlorohydrins/di-chlorohydrins) for the amminoacid series, which was not observed for the glycolic acids. A kinetic model and reaction mechanism developed in a previous work were used for interpreting the kinetic runs.

Catalysis for esterification reactions: a key step in the biodiesel production from waste oils

AbstractOne possible method to produce biodiesel from waste oils (characterized by high concentrations of Free Fatty Acids, FFA), is the use of a two step process: an esterification reaction of FFA and a subsequent transesterification reaction with methanol of the whole mixture using a basic catalyst. In this review, we report the most important results and the still open challenges in relation to esterification reactions in the presence of homogeneous or heterogeneous catalysts.

A critical review on analytical methods and characterization of butyl and bromobutyl rubber

ABSTRACT The molecular structure characterization of butyl and bromobutyl rubber (BIIR) requires the definition of three main parameters: (I) the unsaturation degree of the rubbers, (II) the total bromine content of the BIIRs, and (III) the functional bromine content of the BIIRs. The analytical methods for the determination of the previously mentioned parameters have been described and critically examined in this review.

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