Rosa Vitiello

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.

Synthesis of Monoalkyl Glyceryl Ethers by Ring Opening of Glycidol with Alcohols in the Presence of Lewis Acids

The present work deals with the production of monoalkyl glyceryl ethers (MAGEs) through a new reaction pathway based on the reaction of glycidol and alcohols catalyzed by Lewis acid-based catalysts. Glycidol is quantitatively converted with high selectivity (99 %) into MAGEs under very mild reaction conditions (80 °C and 0.01 mol % catalyst loading) in only 1 h using Al(OTf)3 or Bi(OTf)3 as catalyst. The proposed method enhances the choice of possible green synthetic approaches for the production of value-added products such as MAGEs.

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.

Niobia supported on silica as a catalyst for Biodiesel production from waste oil

Abstract The activity and stability of niobia supported on silica catalyst have been tested in continuous micro-pilot reactors, for biodiesel production starting from acid vegetable oils. A catalyst was prepared by the impregnation of silica pellets with a loading of 12% of Nb and was extensively characterized. The activity of this catalyst in both esterification and transesterification was tested in a continuous micro-pilot laboratory plant in which acid oil was fed (FFA 10% w/w) at a temperature of 220°C and at a pressure of 60 bar. The niobia based catalyst resulted in a very active catalyst in both esterification (FFA conversion = 95-90%) and transesterification reactions (FAME yield = 80-90%), and the activity remained quite constant for more than 100 h on stream. Notwithstanding this stability, a non-negligible leaching phenomena has been detected, in the case of long-time continuous runs, as the Nb concentration on the spent catalyst resulted lower than that on the fresh one. The obtained result confirms that the leaching of the active specie is one of the most strong problem in heterogeneous catalysis for biodiesel production.

Confocal microscopy and imaging profilometry: A new tool aimed to evaluate aesthetic procedures

According to the American Academy of Aesthetic Plastic Surgeons, more than 11 million cosmetic surgical and nonsurgical procedures were performed by board-certified plastic surgeons, dermatologists and otolaryngologists in the United States, totaling more than 12 billion dollars. We performed a retrospective observational multi-centric study on patients treated with a non-animal origin cross-linked hyaluronic acid with different molecular weights for nasolabial folds, evaluating through a new imaging system, profilometric techniques with the confocal microscopy, the durability, the efficacy and the safety of this product. From 25 patients, 150 silicone casts were obtained: 75 casts of the right nasolabial fold and 75 casts of the left nasolabial fold. Roughness arithmetical average of the right fold at T2 decreased by 50% versus T0 and by 40% compared to T1; at T2, it decreased by the 45% versus T0 and by 35% compared to T1. No side effects were reported. Results proved that the analysis of the skin microreliefs through confocal microscopy is a new imaging system that allows to evaluate with precision and safety the results of aesthetic treatments such as fillers objectively.

Catalytic Processes in Biorefinery

The biorefinery is a system that uses as feedstocks biomasses and recover from these energy, fuel and chemicals. There are many processes considered in the biorefinery system, but in this thesis the biorefinery that uses as feedstock oil, in particular dedicated crops and waste vegetable oils were considered. In the first part of this thesis the biodiesel production process was studied. One possible route to produce biodiesel from waste oils (carachetrized by high concentrations of Free Fatty Acids, FFAs), is the use of a two steps process: an esterification reaction of FFAs with glycerol and a successive transesterification reaction with methanol of the whole mixture using a basic catalyst. In this thesis the esterification step of FFAs with glycerol, in presence of a new acid heterogeneous catalyst based on sulfonated polymers with enhanced temperature resistance, was studied. The use of this type of catalyst has the advantage of using a relatively high temperature favouring the reaction by stripping of water formed during the esterification The use of an acid catalyst that is able to tranesesterify the glycerides and to esterify the FFAs is onther way to obtained biodiesel from waste or non edible oils. In this thesis the reactions of contemporany esterification of FFAs and tranesterification of glycerides were studied using new homogeneous or supported homogneous Zn(II) catalysts and a NbO2/SiO2 heterogeneous catalyst. The second part of this thesis was devoted to study of new catalysts for chlorination reaction of glycerol recovered from biodiesel production process.The behavior of three series of homologous catalysts, chloroacetic acid series (acetic acid, monochloroacetic, dichloroacetic and trichloroacetic acid), 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 to produce dichlorohydrins, important intermediates for epichlorohydrin production. In the present study we explored also a completely new class of catalysts for glycerol chlorination, represented by acyl chlorides, never reported in the literature. The catalysts studied are acetyl chloride, propanoyl chloride, adypoyl chloride, butandioil di-chloride, propandioil di-chloride and phenylacetyl chloride and more precisely it is reported a comparison between the acyl chlorides respect to corresponding carboxylic acid. The influence of some reaction parameters are studied as for example the effects of the pressure on activity and selectivity. Finally I use acyl chloride in stoichiometric amount in order to open new opportunities for chlorination process of glycerol with hydrochloric acid performed in situ.