Kinetic study of 1‐butanol dehydration to di‐n‐butyl ether over Amberlyst 70

Abstract

8Kinetics of the catalytic dehydration of 1-butanol to di-n-butyl ether (DNBE) over 9Amberlyst-70 was investigated. Experiments were performed in liquid phase at 4 MPa and 10 413-463 K. Three elementary reaction mechanisms were considered: a Langmuir-Hinselwood-11Hougen-Watson (LHHW) formulation; an Eley-Rideal (ER) formulation in which DNBE 12 remains adsorbed; an ER formulation in which water remains adsorbed. 13Two kinetic models explain satisfactorily the dehydration of 1-butanol to DNBE: a LHHW 14 formalism in which the surface reaction between two adjacent adsorbed molecules of 1-butanol 15 is the rate limiting step (RLS) and where the adsorption of water is negligible, and a mechanism 16 in which the RLS is the desorption of water being the adsorption of DNBE negligible. In both 17 models the strong inhibiting effect of water was successfully taken into account by means of a 18 correction factor derived from a Freundlich adsorption isotherm. Both models present similar 19 values of apparent activation energies (122±2 kJ/mol).

Esterification of levulinic acid with butanol over ion exchange resins

“…the esterification of lactic acid with methanol [55] or that of acrylic acid with 2-ethyl hexanol [56] over Amberlyst 15. In addition, the dehydration reactions to ether of 1-butanol [53] or 1-hexanol [54] on Amberlyst 70, or 1-pentanol over CT224 and Dowex 50Wx4 [51] at temperatures as high as 150 0 C also shows that external mass transfer influence at such stirring speed is negligible.…”

“…The use of such small catalyst mass (0.5 g of dry catalyst; catalyst loading < 1%) allows us to work free of spurious effects on the reaction rate as can be seen in the dehydration reactions to ether of 1-butanol [53] or 1-hexanol [54] on Amberlyst 70, or 1-pentanol over CT224 and Dowex 50Wx4 [51] carried out in similar setups.…”

“…It should be noted also that some macroporous resins, despite having some desulfonation at 150 0 C may be reused for some cycles. In particular, Amberlyst 15, whose maximum operating temperature is 120 0 C, might be reused several times at 150 0 C without activity loss as it was shown in dehydration reaction of 1-butanol to di-n-butyl ether [53]. In this case, morphology changes provides higher surface area, but some desulfonation is detected.…”

Kinetics of the liquid phase dehydration of 1‐octanol to di‐n‐octyl ether on Amberlyst 70

“…parameters is low. As Table shows, this value is a bit smaller that those of the reactions of dehydration of butanol to di‐n‐butyl ether (DNBE, 122 ± 2 kJ·mol −1 ), of pentanol to DNPE (114 ± 0,1 kJ·mol −1 ), and hexanol to DNHE (121 ± 3 kJ·mol −1 ), respectively, on Amberlyst 70. Conversely, in the dehydration of ethanol and 1‐octanol to ethyl octyl ether, DNOE synthesis is a side reaction with similar activation energy on Amberlyst 70 (99 kJ·mol −1 ) and on CT‐482 (100 kJ·mol −1 ) .…”

Experimental Study on the Liquid‐Phase Adsorption Equilibrium of n‐Butanol over Amberlyst™15 and Contribution of Diffusion Resistances

“…In the catalytic process, compound adsorption on the resin plays a crucial role. Adsorption equilibrium constants appear in the kinetic equation of heterogeneously catalyzed reactions and, therefore, they are usually estimated from the fit of kinetic models to experimental data [28][29][30][31]. The weaknesses of such estimations are often the large cross-correlation between different adsorption constants and the fact that the more readily adsorbed compounds can mask the weak adsorption of other species.…”