Equilibrium of simultaneous tert-amyl ethyl ether and tert-amyl alcohol formation reactions
Tutor / director / evaluatorLINNENKOSKI, JUHA
Document typeMaster thesis (pre-Bologna period)
Rights accessRestricted access - confidentiality agreement
The main purpose of this thesis was to study the equilibria of simultaneous tert-amyl ethyl ether and tert-amyl alcohol formation reactions by means of an acidic ion-exchange resin catalyst. The literature review presents an introduction into the oxygenate market. There, a general overview on its evolution and its current situation is introduced. Furthermore, a deep study of some important oxygenates is presented and their main benefits and drawbacks are stressed. Finally, thermodynamical and kinetical data for all the possible reactions to occur are presented under different reaction conditions. The effect of temperature and different concentrations of water in the initial feed mixture were tested, in the experimental part. All the experiments were carried out in a 80 ml batch reactor. The experiments were conducted at 60 and 80 °C and amounts of water varying from 0 to 4.5 mass % of ethanol were introduced in the initial feed mixtures. Moreover, all the experiments were repeated modifying the initial amount of isoamylenes (2-methyl-1-butene and 2-metyl-2-butene). Iso-octane was used as a solvent in all the experiments, not only in order to ehance conversions and selectivities, but also trying to simulate conditions in a possible future industrial production. Amberlyst 35wet was used to catalyse the reaction. Although simultaneous etherification and hydration reactions of isoamylenes were found to be thermodynamically limited, tert-amyl ethyl ether formation is always favored over tert-amyl alcohol production. Values from 33 to 69 % were obtained for isoamylenes conversions. Reagents selectivities to tert-amyl ethyl ether reached values between 72 and 97 % whereas selectivities to tert-amyl alcohol were only from 2 to 16 %. Equilibrium constant values were between 0.66 and 1.94 for the etherification reaction while 0.29 - 1.66 were the values calculated for the hydration of isoamylenes. Temperature increased reactions rates while it diminished conversions and equilibrium constants. Selectivity to tert-amyl alcohol increased with temperature whereas it dropped selectivity to tert-amyl ethyl ether. The presence of water was found to affect dramatically tert-amyl ethyl ether formation. Therefore, reaction rates, conversions of the olefins and selectivities to tert-amyl ethyl ether were decreased by increasing water concentration. Only selectivities to tert-amyl alcohol were increased.