The problem of acidity in concentrated aqueous solutions of sulfuric acid

Marziano, Nunziata Clara; Tomasin, Alberto; Tortato, Claudio; Isandelli, P

doi:10.1039/a803473g

Cited by 20 publications

(40 citation statements)

References 29 publications

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“…The latter were evaluated by the "activity coefficient functions" as parameters related to variations of activity coefficients of the different acidic mixtures [11][12][13][14]. Indeed, a number of studies in concentrated aqueous solutions of strong acids (HA) applied both to dissociation of HA (equilibrium 1) and to protonation of weak bases (B) (equilibrium 2) shows that the activity coefficient terms of thermodynamic Eqs.…”

Section: Kinetic Behaviour Of Oximesmentioning

confidence: 99%

“…Such a procedure, widely tested in the studies of equilibria [10][11][12][13][14] and reactivity [14,21,22] allows to obtain a reliable description of a process in nonideal acid systems and rate constants (k o ) referred to water as standard state, the latter to be used, especially, for comparing solutes in different acids.…”

Section: Kinetic Behaviour Of Oximesmentioning

confidence: 99%

“…The starting oximes in acetone-d and the species formed at suitable time when the oximes were dissolved in different acids have been studied by 1 H NMR, 13 C NMR, and 15 N NMR spectroscopy. The spectra were recorded on two Brucker "Avance" spectrometers equipped with a variable-temperature probe and operating the first at 300.152 ( 1 H NMR), at 75.480 ( 13 C NMR), and at 30.420 ( 15 N NMR) and the second at 400.13 and 100.61 MHz, respectively, for 1 H NMR, 13 C NMR.…”

Section: Nmr Measurementsmentioning

confidence: 99%

“…The spectra were recorded on two Brucker "Avance" spectrometers equipped with a variable-temperature probe and operating the first at 300.152 ( 1 H NMR), at 75.480 ( 13 C NMR), and at 30.420 ( 15 N NMR) and the second at 400.13 and 100.61 MHz, respectively, for 1 H NMR, 13 C NMR.…”

Section: Nmr Measurementsmentioning

confidence: 99%

“…The values were obtained by taking into account: (i) the effective concentrations of the reacting species involved in the rearrangement, (ii) the acidic properties of the medium described by "an activity coefficient function," and (iii) the interactions between solutes and solvents described by "the protonating ability" of the acid systems under investigation [11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

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On the Beckmann rearrangement of ketoximes: A kinetic study in trifluoromethanesulfonic acid

Marziano¹,

Ronchin²,

Tortato³

et al. 2004

Int J of Chemical Kinetics

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The formation and the destruction of an intermediate involved in the Beckmann rearrangement of 2,4,6-trimethylacetophenone oxime have been studied in concentrated trifluoromethanesulfonic acid by kinetic and spectroscopic measurements. Observed (k obs ) and thermodynamic rate constants (k o ) have been estimated and the values compared with the ones obtained in perchloric, sulfuric, and methanesulfonic acids. In the range 80-100 wt% of sulfuric acid, combined analysis of k obs and k o rates shows a specific catalysis due to [H 2 SO 4 ] species. In trifluoromethanesulfonic acid, lower rate constants, compared to the values in sulfuric acid, have been observed which differ at 99 wt% by a factor of 10 3 ca. The catalytic effect of different strong acids, the structure of the intermediate inferred from Raman and NMR spectra, and the role of the ion-pairs involved in the reaction are discussed. C

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Section: Kinetic Behaviour Of Oximesmentioning

confidence: 99%

Section: Kinetic Behaviour Of Oximesmentioning

confidence: 99%

Section: Nmr Measurementsmentioning

confidence: 99%

Section: Nmr Measurementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

On the Beckmann rearrangement of ketoximes: A kinetic study in trifluoromethanesulfonic acid

Marziano¹,

Ronchin²,

Tortato³

et al. 2004

Int J of Chemical Kinetics

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Refined electrolyte‐NRTL model: Activity coefficient expressions for application to multi‐electrolyte systems

2008

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in Wiley InterScience (www.interscience.wiley.com).The influence of simplifying assumptions of the electrolyte-nonrandom two-liquid (NRTL) model in the derivation of activity coefficient expressions as applied to multi-electrolyte systems is critically examined. A rigorous and thermodynamically consistent formulation for the activity coefficients is developed, in which the simplifying assumption of holding ionic-charge fraction quantities constant in the derivation of activity coefficient expressions is removed. The refined activity coefficient formulation possesses stronger theoretical properties and practical superiority that is demonstrated through a case study representing the thermodynamic properties and speciation of dilute to concentrated aqueous sulfuric acid solutions at ambient conditions. In this case study phenomena, such as hydration, ion pairing, and partial dissociation are all taken into account. The overall result of this study is a consistent, analytically derived, short-range interaction contribution formulation for the electrolyte-NRTL activity coefficients and a very accurate representation of aqueous sulfuric acid solutions at ambient conditions at concentrations up to 50 molal. 2008 American Institute of Chemical Engineers AIChE J, 54: [1608][1609][1610][1611][1612][1613][1614][1615][1616][1617][1618][1619][1620][1621][1622][1623][1624] 2008 Keywords: electrolyte thermodynamics, electrolyte-NRTL, ionic activity coefficients, multi-electrolyte solutions, mixing of electrolytes, aqueous sulfuric acid IntroductionThe electrolyte-nonrandom two-liquid (NRTL) model 1 has been extensively applied to represent thermodynamic properties of various electrolyte systems. Examples include mean ionic activity coefficients of aqueous strong electrolytes 1,2 and aqueous organic electrolytes, 3 phase behavior of weak electrolytes, 1 strong acids, 4 mixed-solvent electrolytes, 5 and so forth. The main reasons for its wide acceptance and application are the incorporation of semi-fundamental chemical theories such as the NRTL model for the simulation of local Correspondence concerning this article should be addressed to G. M. Bollas at bollas@mit.edu. *Disclaimer: This paper was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any age...

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Intensification of the Sulfuric Acid Alkylation Process with Trifluoroacetic Acid

Zhang

2018

AIChE Journal

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H 2 SO 4 alkylation of isobutane and butene is one of the primary commercial processes used to produce alkylates. This work presents a technology for the intensification of sulfuric acid alkylation with the addition of trifluoroacetic acid (TFA). The addition of TFA increased the solubility of isobutane in H 2 SO 4 , decreased its viscosity, and adjusted the acidity of H 2 SO 4 . With the addition of TFA, the selectivity of C8 was dramatically improved from 36.8 to 95.7%. The TFA content, stirring speed, reaction temperature, volume ratio of acid to hydrocarbon (H/C), molar ratio of isobutane to 2-butene (I/O), reaction time, and reuse of H 2 SO 4 /TFA were also investigated in this work. Compared with the conventional process, the new technology provided a considerably higher quality alkylation with considerably lower energy consumption.

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The problem of acidity in concentrated aqueous solutions of sulfuric acid

Cited by 20 publications

References 29 publications

On the Beckmann rearrangement of ketoximes: A kinetic study in trifluoromethanesulfonic acid

On the Beckmann rearrangement of ketoximes: A kinetic study in trifluoromethanesulfonic acid

Refined electrolyte‐NRTL model: Activity coefficient expressions for application to multi‐electrolyte systems

Intensification of the Sulfuric Acid Alkylation Process with Trifluoroacetic Acid

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