Reaction kinetics of carbon dioxide with aqueous solutions of L-Arginine, Glycine & Sarcosine using the stopped flow technique

Nafis Mahmud, Abdelbaki Benamor, Mustafa S. Nasser, Jaber Al Marri, Hazim Qiblawey, Paitoon Tontiwachwuthikul

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8 Citations (Scopus)

Abstract

The use of amino acids as potential solvents for carbon dioxide (CO2) capture has been considered by a number of researchers. However, very little is known about the kinetics and mechanism of amino acids-CO2 reactions. In this work, we investigate the reactions of three amino acids (L-Arginine, Glycine and Sarcosine) with CO2 in aqueous media using stopped-flow conductivity technique. The experiments were performed at temperatures between 293 and 313 K and amino acids concentrations were in the range of 0.05–0.2 molar. The overall rate constants (kov) was found to increase with increased amino acid concentration and solution temperature. Both zwitterion and termolecular mechanisms were used to model and interpret the data. However, the Zwitterion mechanism was found to be the preferred one. From the stopped-flow results at pH around 6, we found that neutral L-Arginine, Glycine and Sarcosine react with CO2(aq) with k(M−1 s−1) = 2.81 × 1010exp(−4482.9T(K)), k(M−1 s−1) = 3.29 × 1013exp(−8143.7T(K)) and k(M−1 s−1) = 3.90 × 1013exp(−7991.0T(K)) respectively. The corresponding activation energies are 37.28 kJ mol−1, 67.71 kJ mol−1 And 66.44 kJ mol−1 respectively. A comparison between the kinetics of the three amino acids showed that Arginine exhibits highest reaction rate with CO2 followed by Sarcosine and then Glycine. The technique and results obtained from this work can be used as strong tools in the development of efficient new solvents for the removal of CO2 from flue and industrial gases.

Original languageEnglish
Pages (from-to)47-58
Number of pages12
JournalInternational Journal of Greenhouse Gas Control
Volume63
DOIs
Publication statusPublished - 1 Jan 2017
Externally publishedYes

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Keywords

  • Arginine
  • Carbon dioxide
  • Glycine
  • Kinetics
  • Sarcosine
  • Stopped flow technique

ASJC Scopus subject areas

  • Pollution
  • Energy(all)
  • Industrial and Manufacturing Engineering
  • Management, Monitoring, Policy and Law

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