Gas-liquid-liquid reaction engineering: the Koch synthesis of pivalic acid from iso- and tert-butanol; Reaction kinetics and the effect of a dispersed second-liquid phase

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Abstract

In gas–liquid–liquid reaction systems with fast parallel and consecutive reactions the effects of mass transfer and mixing on the product yield can be significant. The Koch synthesis of pivalic acid, using sulfuric acid as catalyst, was chosen to study these effects. Reaction kinetics and the effect of the catalyst-phase composition have been investigated by using isobutanol as reactant. For studying the effect of an immiscible liquid phase on the reaction products obtained, the more reactive tert-butanol was used. Pivalic acid can be produced from isobutanol using sulfuric acid as a catalyst solution with 2-methylbutanoic acid as main byproduct, if gas–liquid mass transfer limitations are excluded. The selectivity towards 2-methylbutanoic acid is generally less than 20% and decreases strongly with decreasing acidity. The reaction is first order in isobutanol and dehydration is likely to be rate determining. The presence of pivalic acid and isobutanol strongly reduces the apparent reaction rate constant by decreasing the solution acidity (Ho). For the industrially applied backmixed reactors in the Koch synthesis, this may imply that these operate at much lower values for Ho. On addition of an immiscible heptane phase, the reaction products are extracted to some extent and this adds to maintaining a high catalyst solution acidity. Using tert-butanol, the yield and pivalic acid selectivity was found to depend strongly on CO transport to the reaction zone through gas–liquid mass transfer and mixing. The presence of an immiscible heptane phase increased the product yield and selectivity towards pivalic acid significantly.
Original languageUndefined
Pages (from-to)4801-4809
Number of pages8
JournalChemical engineering science
Volume54
Issue number21
DOIs
Publication statusPublished - 1999

Keywords

  • METIS-106437
  • IR-74164

Cite this

@article{8d18a9dc83d9483ca2cbde48ad965fb4,
title = "Gas-liquid-liquid reaction engineering: the Koch synthesis of pivalic acid from iso- and tert-butanol; Reaction kinetics and the effect of a dispersed second-liquid phase",
abstract = "In gas–liquid–liquid reaction systems with fast parallel and consecutive reactions the effects of mass transfer and mixing on the product yield can be significant. The Koch synthesis of pivalic acid, using sulfuric acid as catalyst, was chosen to study these effects. Reaction kinetics and the effect of the catalyst-phase composition have been investigated by using isobutanol as reactant. For studying the effect of an immiscible liquid phase on the reaction products obtained, the more reactive tert-butanol was used. Pivalic acid can be produced from isobutanol using sulfuric acid as a catalyst solution with 2-methylbutanoic acid as main byproduct, if gas–liquid mass transfer limitations are excluded. The selectivity towards 2-methylbutanoic acid is generally less than 20{\%} and decreases strongly with decreasing acidity. The reaction is first order in isobutanol and dehydration is likely to be rate determining. The presence of pivalic acid and isobutanol strongly reduces the apparent reaction rate constant by decreasing the solution acidity (Ho). For the industrially applied backmixed reactors in the Koch synthesis, this may imply that these operate at much lower values for Ho. On addition of an immiscible heptane phase, the reaction products are extracted to some extent and this adds to maintaining a high catalyst solution acidity. Using tert-butanol, the yield and pivalic acid selectivity was found to depend strongly on CO transport to the reaction zone through gas–liquid mass transfer and mixing. The presence of an immiscible heptane phase increased the product yield and selectivity towards pivalic acid significantly.",
keywords = "METIS-106437, IR-74164",
author = "Brilman, {Derk Willem Frederik} and {van Swaaij}, {Willibrordus Petrus Maria} and Geert Versteeg",
year = "1999",
doi = "10.1016/S0009-2509(99)00197-9",
language = "Undefined",
volume = "54",
pages = "4801--4809",
journal = "Chemical engineering science",
issn = "0009-2509",
publisher = "Elsevier",
number = "21",

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TY - JOUR

T1 - Gas-liquid-liquid reaction engineering: the Koch synthesis of pivalic acid from iso- and tert-butanol; Reaction kinetics and the effect of a dispersed second-liquid phase

AU - Brilman, Derk Willem Frederik

AU - van Swaaij, Willibrordus Petrus Maria

AU - Versteeg, Geert

PY - 1999

Y1 - 1999

N2 - In gas–liquid–liquid reaction systems with fast parallel and consecutive reactions the effects of mass transfer and mixing on the product yield can be significant. The Koch synthesis of pivalic acid, using sulfuric acid as catalyst, was chosen to study these effects. Reaction kinetics and the effect of the catalyst-phase composition have been investigated by using isobutanol as reactant. For studying the effect of an immiscible liquid phase on the reaction products obtained, the more reactive tert-butanol was used. Pivalic acid can be produced from isobutanol using sulfuric acid as a catalyst solution with 2-methylbutanoic acid as main byproduct, if gas–liquid mass transfer limitations are excluded. The selectivity towards 2-methylbutanoic acid is generally less than 20% and decreases strongly with decreasing acidity. The reaction is first order in isobutanol and dehydration is likely to be rate determining. The presence of pivalic acid and isobutanol strongly reduces the apparent reaction rate constant by decreasing the solution acidity (Ho). For the industrially applied backmixed reactors in the Koch synthesis, this may imply that these operate at much lower values for Ho. On addition of an immiscible heptane phase, the reaction products are extracted to some extent and this adds to maintaining a high catalyst solution acidity. Using tert-butanol, the yield and pivalic acid selectivity was found to depend strongly on CO transport to the reaction zone through gas–liquid mass transfer and mixing. The presence of an immiscible heptane phase increased the product yield and selectivity towards pivalic acid significantly.

AB - In gas–liquid–liquid reaction systems with fast parallel and consecutive reactions the effects of mass transfer and mixing on the product yield can be significant. The Koch synthesis of pivalic acid, using sulfuric acid as catalyst, was chosen to study these effects. Reaction kinetics and the effect of the catalyst-phase composition have been investigated by using isobutanol as reactant. For studying the effect of an immiscible liquid phase on the reaction products obtained, the more reactive tert-butanol was used. Pivalic acid can be produced from isobutanol using sulfuric acid as a catalyst solution with 2-methylbutanoic acid as main byproduct, if gas–liquid mass transfer limitations are excluded. The selectivity towards 2-methylbutanoic acid is generally less than 20% and decreases strongly with decreasing acidity. The reaction is first order in isobutanol and dehydration is likely to be rate determining. The presence of pivalic acid and isobutanol strongly reduces the apparent reaction rate constant by decreasing the solution acidity (Ho). For the industrially applied backmixed reactors in the Koch synthesis, this may imply that these operate at much lower values for Ho. On addition of an immiscible heptane phase, the reaction products are extracted to some extent and this adds to maintaining a high catalyst solution acidity. Using tert-butanol, the yield and pivalic acid selectivity was found to depend strongly on CO transport to the reaction zone through gas–liquid mass transfer and mixing. The presence of an immiscible heptane phase increased the product yield and selectivity towards pivalic acid significantly.

KW - METIS-106437

KW - IR-74164

U2 - 10.1016/S0009-2509(99)00197-9

DO - 10.1016/S0009-2509(99)00197-9

M3 - Article

VL - 54

SP - 4801

EP - 4809

JO - Chemical engineering science

JF - Chemical engineering science

SN - 0009-2509

IS - 21

ER -