Characterization of coke deposited on spent catalysts for long-chain-paraffin dehydrogenation

Songbo He, Chenglin Sun*, Xu Yang, Bin Wang, Xihai Dai, Ziwu Bai

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

43 Citations (Scopus)

Abstract

The chemistry, morphology, and structure character of coke deposited on spent catalysts for long-chain-paraffin (n-C(16-19)) dehydrogenation and the effect of coke on the surface structure of the catalysts were studied by several characterization techniques: thermogravimetry/differential thermal analysis (TG-DTA), elemental analysis, UV Raman spectroscopy, temperature-programmed oxidation (TPO), scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunaucr-Emmett-Teller (BET), mercury intrusion porosimetry (MIP) and CO-chemisorption. During the dehydrogenation of n-C(16-19), coke gradually accumulates on the surfaces of the catalysts while the coking rate and the H/C mole ratio of the coke decrease. After the times on stream (TOS) of 960h, the coke deposition on the catalysts is up to 6.56 wt.%, and the H/C mole ratio of the coke is only 0.86. The coke is graphited or amorphous nature and contains conjugated olefinic species and polycyclic aromatic hydrocarbons (PAHs). The coke causes a significant deactivation of the active sites. As compared with the fresh catalysts, the surface area, the total pore volume and the Pt dispersion of the spent catalysts are decreased 19.4%, 33.3% and 61.2%. (C) 2010 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)389-394
Number of pages6
JournalChemical Engineering Journal
Volume163
Issue number3
DOIs
Publication statusPublished - 1-Oct-2010
Externally publishedYes

Keywords

  • Dehydrogenation
  • Coke
  • Deactivation
  • Long chain paraffin
  • Pt-Sn catalysts
  • PT-SN CATALYSTS
  • ALKANE DEHYDROGENATION
  • REFORMING CATALYSTS
  • DEACTIVATION
  • ALUMINA
  • OLEFINS
  • PT-SN-K/AL2O3
  • CONVERSION
  • CHEMISTRY
  • ZEOLITES

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