Selective hydrogenation of propyne over an ion-exchanged copper on silica catalyst

J. T. Wehrli*, D. J. Thomas, M. S. Wainwright, D. L. Trimm, N. W. Cant

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

52 Citations (Scopus)

Abstract

The selective hydrogenation of propyne over a Cu/SiO2 catalyst in a dynamic flow system has been investigated. It was found that only propene and, depending on the reaction conditions, different amounts of oligomeric material, referred to as green oil or foulant, were formed. However, the selectivity to propene increased significantly at higher temperatures and it was possible to convert all the propyne selectively to propene, leaving a great potential for further development and industrial applications. Deactivation of the catalyst was found to be only a minor problem as 100% conversion and a selectivity of > 99.5% was obtained during a long-term test with an industrial raw propene feed (2 mol-%propyne/propadiene), even after one month on line. It is interesting to note that even at high propene concentrations and high temperatures no propane was detected. The conversion of propyne increased with temperature and reached 100% above 160°C. Between 90 and 150°C the selectivity was constant at about 20%, irrespective of hydrogen and propyne concentrations, the degree of conversion, the total flow-rate or the temperature. The addition of propene to the initial mixture decreased the conversion slightly but increased the selectivity markedly. It was possible to obtain 100% conversion of propyne to propene with nearly 100% selectivity at higher temperatures. The kinetic data observed showed a reaction order of zero for propyne at 100°C and a slightly positive reaction order (0.15) at 130°C. The reaction order was one for hydrogen irrespective of temperature. Propene decreased the activity slightly, corresponding to a reaction order of -0.16. The activation energy (68.6kJ/mol±5kJ/mol) was similar for the formation of propene and green oil between 90 and 150°C.

Original languageEnglish
Pages (from-to)199-208
Number of pages10
JournalApplied Catalysis
Volume66
Issue number1
DOIs
Publication statusPublished - 1990

Keywords

  • ageing
  • alkyne hydrogenation
  • coke formation
  • copper/silica
  • kinetics
  • selectivity (propene)

Fingerprint Dive into the research topics of 'Selective hydrogenation of propyne over an ion-exchanged copper on silica catalyst'. Together they form a unique fingerprint.

Cite this