Mechanistic modeling of hydrolysis and esterification for biofuel processes

Shujauddin Changi, Tanawan Pinnarat, Phillip E. Savage

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

We have elucidated the mechanism for ethyl oleate hydrolysis in high temperature water and its reverse reaction, oleic acid esterification in near- and supercritical ethanol in the absence of any other added compounds. Both reactions are acid catalyzed. H+ (from dissociation of water and oleic acid) and oleic acid serve as catalysts for hydrolysis and H+ alone is the catalyst for esterification. The rate equation arising from the proposed mechanism provided a good fit of experimental conversion data for both hydrolysis and esterification. The rate equation accurately predicted the influence of pH on hydrolysis for acidic and near-neutral conditions. The mechanistic model exhibits the ability to make quantitatively accurate predictions within and outside the original parameter space, especially for a multicomponent system. Sensitivity analysis shows that the values of the dissociation constant of oleic acid in ethanol, water, and ethanol-water systems strongly influence the predicted conversions. There is a need for experimental measurement of pKa for fatty acids in both water and alcohols at elevated temperatures.

Original languageEnglish (US)
Pages (from-to)12471-12478
Number of pages8
JournalIndustrial and Engineering Chemistry Research
Volume50
Issue number22
DOIs
StatePublished - Nov 16 2011

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Biofuels
Esterification
Oleic acid
Hydrolysis
Oleic Acid
Water
Ethanol
Catalysts
Fatty acids
Sensitivity analysis
Alcohols
Fatty Acids
Hydrogen
Temperature
Acids

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

Cite this

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Mechanistic modeling of hydrolysis and esterification for biofuel processes. / Changi, Shujauddin; Pinnarat, Tanawan; Savage, Phillip E.

In: Industrial and Engineering Chemistry Research, Vol. 50, No. 22, 16.11.2011, p. 12471-12478.

Research output: Contribution to journalArticle

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AU - Changi, Shujauddin

AU - Pinnarat, Tanawan

AU - Savage, Phillip E.

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