A new method for analysis of coke on catalysts

Abstract

Both on-line dynamic headspace (HS) sampling and high temperature capillary separation were used in the GC-MS analysis of the volatile components of coke. The results showed that an open-tubular trap with a thick liquid film is better than a trap packed with Tenax-GC adsorbent for preconcentration of the volatile components of coke. Compared with the latter and with the previously reported analysis of soluble coke with solvent extraction, the proposed method can determine more components of coke on catalysts, allowing the determination of polynuclear aromatics with up to nine rings. The mean recovery of reference compounds was 97.1% with RSDs of 1.5–4.8%, sufficient to meet the requirements for the analysis of coke on catalysts.