Nuevas rutas más respetuosas con el medio ambiente para la síntesi de 2-feniletanol y óxido de estireno

Identificador:  TDX:314

Handle: https://hdl.handle.net/20.500.11797/TDX314

Autors:  Kirm, Ilham

Resum:
2-Phenylethyl alcohol (commonly known as 2-phenethyl alcohol) is the main component of rose oils obtained from rose blossoms. It is one of the most widely used of all perfume chemicals. Industrially, 2-phenethyl alcohol can be synthesized by Friedel-Crafts alkylation of benzene using ethylene oxide with molar quantities of aluminium chloride as catalyst. However, the stoichiometric use of the highly corrosive aluminium chloride causes important effluent disposal problems due to the formation of aluminium oxychloride during the process. Therefore, it is necessary to develop new technologies cleaner and more respectful with the environment to produce 2-phenethyl alcohol.<br/>An interesting alternative is the selective hydrogenation of styrene oxide. Although several patents are available, mainly in discontinuous reactors in liquid phase, published basic information is conspicuously absent. The reaction mechanism, correlation between activity and selectivity with the active phase of the catalyst and its preparation, the effect of the acidbase properties of the support on the active phase, the catalyst life etc., are not well known.<br/>The aim of this work is the study at laboratory scale the selective hydrogenation of styrene oxide to obtain 2-phenethyl alcohol. The reaction is carried out using different reactors design such as continuous reactor in gas phase and batch reactor in liquid phase. Several active phases such as Ni, Pd and Pt on different supports (magnesia, alumina and activated carbon) will be tested.<br/>However, one possible disadvantage for the industrial application of this process could<br/>be the price and/or the availability of styrene oxide. For this reason, another aim of this work is the study of the selective oxidation of styrene to obtain styrene oxide or/and phenylacetaldehyde in order to hydrogenate it in a second stage to obtain 2-phenyethanol.<br/>The selective oxidation of styrene was investigated in phase gas (using air or oxygen as oxidant) using a continuous reactor, as well as in batch reactor working in liquid phase with hydrogen peroxide as oxidant. In gas phase we have study the catalytic behaviour of silver nanoparticles with different morphologies (nanowires, nanopolyhedra and amorphous particles) on different supports such as corundum and magnesia in order to correlate the crystalline planes exposed on the surface of the nanoparticles with their catalytic behaviour.<br/>In liquid phase we have study the synthesis of hydrotalcite-like materials with different<br/>Mg/Al molar ratios to see the influence of the textural and basic properties of these materials in the catalytic properties.