Catalizzatori polifunzionali per la sintesi di Metil Isobutil Chetone

Fazzini, Francesco (2016) Catalizzatori polifunzionali per la sintesi di Metil Isobutil Chetone. [Laurea magistrale], Università di Bologna, Corso di Studio in Chimica industriale [LM-DM270], Documento ad accesso riservato.
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Abstract

In this work, we have examined the activity and selectivity of new catalysts for the single-stage production of methyl isobutyl ketone (MIBK, 4- methyl-2-pentanone) from acetone (both in liquid and gas phase), using a fixed bed reactor operated in the temperature range between 373 and 473 K. The main reaction pathways for the synthesis of MIBK from acetone are given in Fig.1. The first step is the self condensation of acetone to diacetone alcohol (DAA, 4-hydroxy-4-methyl-2-pentanone); the second step is the dehydration of DAA to mesityl oxide (MO, 4-methyl-3-penten-2-one); the final step is the selective hydrogenation of the carbon–carbon double bond of MO to form MIBK. The most commonly observed side reactions are over-condensations and unselective hydrogenations (also shown in Fig.1). Two types of catalysts were studied: i)Pd supported on MgO-SiO2 mixed oxides with ratio of Mg to Si, synthetized using Ohnishi’s method and ii)Pd supported on alumina doped with 5% or 10% of MgO. The different Mg-Si and Mg-Al catalysts were characterized by different techniques (XRD, BET, SEM, NH3-TPD and CO2-TPD) and tested under different conditions in the condensation of acetone to diacetone alcohol and its dehydration to mesityl oxide to enhance the activity. Palladium was chosen as metal component, and its hydrogenation activity was studied. A low hydrogenation activity negatively affects the acetone conversion and promotes the production of mesityl oxide. Hydrogenation conditions being too severe may favor the unwanted hydrogenation of acetone to 2-propanol and of MIBK to methyl isobutyl carbinol (MIBC, 4-methyl-2-pentanol) but this effect is less detrimental to the MIBK selectivity than an unsufficient hydrogenation activity.

Abstract
Tipologia del documento
Tesi di laurea (Laurea magistrale)
Autore della tesi
Fazzini, Francesco
Relatore della tesi
Correlatore della tesi
Scuola
Corso di studio
Ordinamento Cds
DM270
Parole chiave
MIBK metil isobutil chetone IPA isopropil alcool DAA diaceton alcool MO mesitil ossido DIBK diisobutil chetone MIBC metil isobutil carbinolo TAA triaceton alcool selettività conversione LHSV Liquid Hourly Space Velocity
Data di discussione della Tesi
11 Ottobre 2016
URI

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