Radici Chimica SpA

Novara, Italy

Radici Chimica SpA

Novara, Italy
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Solmi S.,University of Bologna | Rozhko E.,University of Bologna | Malmusi A.,University of Bologna | Lolli A.,University of Bologna | And 5 more authors.
DGMK Tagungsbericht | Year: 2014

This paper reports about the results of a study aimed at the development of a more sustainable catalytic process for adipic acid synthesis, by means of a two-step transformation, in which cyclohexene is first transformed into trans-1,2-cyclohexanediol with hydrogen peroxide, and the glycol is then oxidized with oxygen. The first step of our approach gave excellent results, with yield to CHD over 97% and total conversion of cyclohexene. Different catalysts were studied for the second step: (i) heterogeneous catalysts made of alumina-supported Ru(OH)3; (ii) homogeneous Keggin-type P/Mo/V heteropolycompounds, and (iii) supported Au nanoparticles. Catalysts based on Au nanoparticles turned out to be much more selective than alumina-supported Ru(OH)3. This was due to various factors: (a) Au-based catalysts required less basic conditions than Ru-based systems, while strongly basic conditions favored the oxidehydrogenation of CHD into 1,2-cyclohexanedione, which was transformed into 1-hydroxycyclopentanecarboxylic acid and other undesired by-products. (b) the first intermediate in CHD oxidation with Au-based systems was 2-hydroxycyclohexanone, which underwent a very selective oxidation into adipic acid. © 2014. Deutsche Wissens. Gesell. fur Erdoel, Erdgas und Kohle EV. All rights reserved.


Rozhko E.,University of Bologna | Raabova K.,University of Bologna | Macchia F.,University of Bologna | Malmusi A.,University of Bologna | And 7 more authors.
ChemCatChem | Year: 2013

The aerobic oxidation of trans-1,2-cyclohexanediol in the synthesis of adipic acid was studied. Two classes of catalysts are compared, 1)alumina-supported Ru(OH)3, and 2)Keggin type P/Mo/V polyoxometalates. These two classes are representative examples because they are active in alcohol oxidation under quite different reaction conditions. In the former case, basic conditions are needed in order to activate the substrate, whereas with polyoxometalates, acidic conditions are used. Their catalytic behavior showed remarkable differences; in basic conditions, the reaction network was very complex, and several side reactions led to a number of by-products, with a low selectivity to adipic acid in the end. The supported Ru(OH)3 catalyst was very efficient in 1,2-cyclohexanediol oxidative dehydrogenation to 1,2-cyclohexanedione, but several undesired reactions occurred starting from this key intermediate under basic conditions: rearrangement into 6-hydroxycaprolactone and 1-hydroxycyclopentanecarboxylic acid, and formation of the product of aldol condensation. The former compound was also an intermediate for adipic acid formation, but this reaction gave only a minor contribution to the reactant conversion. Polyoxometalates were extremely selective in 1,2-cyclohexanediol conversion into adipic acid, but under acidic conditions the product reacted with the unconverted reactant to yield the corresponding ester. © 2013 WILEY-VCH Verlag GmbH & Co.


Antonetti C.,University of Pisa | Galletti A.M.R.,University of Pisa | Accorinti P.,Radici Chimica SpA | Alini S.,Radici Chimica SpA | And 8 more authors.
Applied Catalysis A: General | Year: 2013

In this paper we compare two different reactions, aimed at the synthesis of 1,2-cyclohexanediol. Specifically: (a) the direct epoxidation and hydrolysis (dihydroxylation) of cyclohexene to trans-1,2-cyclohexanediol, with an aqueous solution of hydrogen peroxide, and (b) the hydrogenation of catechol to a mixture of cis and trans-1,2-cyclohexanediol, in an attempt to establish green protocols for the synthesis of diols. Both reactions, the dihydroxylation of cyclohexene and the hydrogenation of catechol, were carried out without organic solvents. In the former case, an unprecedented 97.4% yield to the glycol was obtained, by selecting proper reaction conditions and using a tungstic acid/phosphoric acid catalyst, in a biphasic system with a phase-transfer agent. In the second approach, a heterogeneous alumina-supported Ru(OH)x catalyst was used, and a 90% yield to the glycol was obtained. A comparison of the two processes allowed to show the lower environmental impact of the catechol hydrogenation route. © 2013 Elsevier B.V. All rights reserved.


Battegazzore D.,Polytechnic University of Turin | Salvetti O.,Polytechnic University of Turin | Frache A.,Polytechnic University of Turin | Peduto N.,Radici Chimica SpA | And 2 more authors.
Composites Part A: Applied Science and Manufacturing | Year: 2016

Composites consisting of fully (PA10.10) and partially (PA6.10) bio-based polyamides and 10-20 wt.% rice husk ash (RHA) was prepared by melt compounding. The mechanical analysis data showed that RHA induced significant improvement in Young's modulus, a slight reduction in the tensile strength and a large decrease in the deformation at break. Pukanszky's model was used to evaluate the filler-matrix interactions. The two PAs exhibited similar filler-matrix load transfer with RHA and better performance than polylactic acid (PLA). The addition of modified clay (Cloisite 30B) to the systems with 10 wt.% of RHA gave the best mechanical properties and filler-matrix interactions, notwithstanding the matrix used. Finally, DMT analyses demonstrated that the addition of RHA caused an increase in the heat deflection temperature (HDT) compared to the neat PA matrices. Furthermore, the simultaneous presence of RHA and clay provided the best results. © 2015 Elsevier Ltd.


Cavani F.,University of Bologna | Ferroni L.,University of Bologna | Frattini A.,University of Bologna | Lucarelli C.,University of Bologna | And 5 more authors.
Applied Catalysis A: General | Year: 2011

This report deals with the results of a study on the oxidation of cyclohexanone to adipic acid with air, catalysed by Keggin-type polyoxometalates of composition H3+xPMo12-xVxO40 (x = 1 and 2), which was carried out in a semi-continuous stirred-tank reactor. It was found that when conducted in the presence of a water-only solvent, the reaction proceeds with a redox mechanism, in which the step of reoxidation of the reduced POM by oxygen is rate limiting. When, however, the reaction was carried out with an acetic acid co-solvent, a radical-chain autoxidation mechanism prevailed, especially when very low amounts of catalyst were used. Autoxidation overlapped with the redox mechanism when the catalyst-to- cyclohexanone ratio was increased. Moreover, the composition of the polyoxometalate, that is, the number of V atoms per Keggin unit, affected the relative importance of the two mechanisms. The selectivity to adipic acid achieved was a function of the reaction mechanism, but also was affected by cyclohexanone conversion, due to the presence of a complex reaction network. © 2010 Elsevier B.V. All rights reserved.


Cavani F.,University of Bologna | Macchia F.,University of Bologna | Pino R.,University of Bologna | Raabova K.,University of Bologna | And 4 more authors.
DGMK International Conference on Catalysis - Innovative Applications in Petrochemistry and Refining | Year: 2011

In this paper, we report about the effect of reaction parameters on catalytic behavior in a twostep process aimed at the synthesis of adipic acid from cyclohexene. In the first step, cyclohexene reacts with an aqueous solution of hydrogen peroxide, under conditions leading to the formation of trans-1,2-cyclohexandiol as the prevailing product; the reaction is catalysed by tungstic acid, in the presence of phosphoric acid and of a PT agent. In the second step, 1,2-cyclohexandiol is oxidized with air, in the presence of an heterogeneous catalyst made of alumina-supported Ru(OH) 3. This process is aimed at using the minimal amount of the costly hydrogen peroxide, since only one mole is theoretically needed per mole of cyclohexene. The first step afforded very high yield to the glycol, using only a slight excess of hydrogen peroxide. However, the second step turned out to be the more critical one, since the selectivity to adipic acid was very low because of the concomitant occurrence of several undesired side reactions. The latter were in part due to the reaction conditions used, which were necessary for the activation of cyclohexandiol.


Patent
Radici Chimica S.p.A. | Date: 2011-04-15

It is described a process for the production of hexamethylenediamine by hydrogenation of adiponitrile, comprising an improved step of regeneration of the catalyst. Also described are an equipment for the production of hexamethylenediamine, and a washing apparatus (14) for implementing the catalyst regeneration step.


Patent
Radici Chimica S.p.A. | Date: 2014-12-09

It is described a process for the production of hexamethylenediamine by hydrogenation of adiponitrile, comprising an improved step of regeneration of the catalyst. Also described are an equipment for the production of hexamethylenediamine, and a washing apparatus (14) for implementing the catalyst regeneration step.

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