Equilibrium of the simultaneous etherification of isobutene and isoamylenes with ethanol in liquid-phase

Abstract

ARTICLE IN PRESS CHERD-1418; No. of Pages 13 chemical engineering research and design x x x ( 2 0 1 3 ) xxx-xxx ethyl tert-butyl ether formation, tert-amyl ethyl ether formation from isoamylenes (2-methyl-1-butene and 2-methyl-2-butene) and isomerization reaction between both isoamylenes. Equilibrium data were obtained in a batchwise IntroductionIn order to reduce hazardous and evaporative gasoline exhausts and from refueling emissions, as well as their environmental impact at the time that engines energetic efficiency is enhanced, new legislation and major efforts have been devoted to fuel reformulation. The European Directive 2009/28/EC promotes the usage of combustibles from renewable resources, such as bioethanol, and the directive 2009/30/EC establishes the main guidelines related to fuel reformulation.As it is well known, olefins of the C 5 fraction from oil, mainly the reactive isoamylenes (IA) 2-methyl-1-butene (2M1B) and 2-methyl-2-butene (2M2B), present some disadvantages as components of a gasoline, particularly in tropical zones. This is because these are the olefins with the highest * Corresponding author. Tel.: +34 934034769; fax: +34 934021291. E-mail addresses: rsotolop7@alumnes.ub.edu (R. Soto), fite@ub.edu (C. Fité), eliana.ramirez-rangel@ub.edu (E. Ramírez), rogerbringue@ub.edu (R. Bringué), fcunill@ub.edu (F. Cunill).Received 25 Reid vapor pressure (RVP), the highest atmospheric reactivity, the highest potential of tropospheric ozone formation (around 90%) and these are the largest amount of the olefins present in a gasoline (above 25 wt.% of the C 5 fraction from fluid catalytic cracking, FCC) (Rock et al., 1992). Thus, to diminish the impact of their use as fuel components on the environment, the reduction of the content of these compounds by means of either its etherification with primary alcohols or via oligomerization would result in a more suitable alternative than the reduction of the total olefin content of a gasoline. Oxygenated compounds have been gradually gaining importance in the gasoline market since lead compounds were banned as octane enhancers. The two main types of oxygenates used as high octane additives are alcohols and ethers. Among alcohols, the most widely used is ethanol (EtOH), whereas the main tertiary ethers are methyl tert-buty ether

Equilibrium conversion, selectivity and yield optimization of the simultaneous liquid-phase etherification of isobutene and isoamylenes with ethanol over Amberlyst™ 35

“…The main reactions are the etherification of EtOH with IB (R1) and IA (R2 and R3), and the double bond isomerization reaction (R4) between both IA (2M1B and 2M2B). Equilibrium constants of reactions R1 to R4, and related thermodynamical properties, have been already estimated and discussed in a previous work [31]. Since water is present in the initial reactant mixture (1 wt.%), hydration of IB and IA (R5, R6 and R7) could also take place to form tertiary alcohols, namely TBA and TAA.…”

“…Several studies have been focused on the performance of isolated production of ETBE and TAEE in both absence and presence of water [25,[27][28][29][30]. But there is scarce information about the simultaneous production of bioethers and, more specifically, concerning equilibrium conversion and selectivity [13,14,[31][32][33][34]. Besides reducing the C 5 olefins content and using EtOH as raw material, the simultaneous production of ETBE and TAEE is a versatile and flexible process, whose integration and intensification can provide several advantages.…”

Kinetic modeling of the simultaneous etherification of ethanol with C4 and C5 olefins over Amberlyst™ 35 using model averaging

“…4, where aj is the activity of compound j, ij is the stoichiometric coefficient of the species j in reaction i, and Ki is the equilibrium constant of reaction i. Values of Ki have been taken from a previous study [5].…”

“…New interesting processes of simultaneous production of several ethers in the same reaction unit are feasible [1][2][3][4][5][6], and they could become an industrial reality in the forthcoming years. Promising conclusions have been drawn regarding thermodynamics and product distribution at experimental conditions of industrial interest.…”

Thermodynamic Analysis of the Experimental Equilibria for the Liquid-Phase Etherification of Isobutene with C1 to C4 Linear Primary Alcohols

“…Even though thermodynamics of the ETBE synthesis (reaction R2 in Scheme 1) has been also extensively dealt with in literature, for instance [31][32][33][34][35][36] , the lack of agreement between sources has often led to a discrepancy between theoretically and experimentally obtained equilibrium constants 36 . Thus, part of this study has been devoted to this reaction.…”