Catalytic partial oxidation of higher hydrocarbons: reactivities and selectivities of mixtures

• Published in: Chemical engineering science 2004-11, Vol.59 (22), p.5501-5507
• Main Authors: Subramanian, R., Panuccio, G.J., Krummenacher, J.J., Lee, I.C., Schmidt, L.D.
• Format: Article
• Language: English
• Subjects: Applied sciences; Catalysis; Catalytic reactions; Chemical engineering; Chemistry; Exact sciences and technology; General and physical chemistry; Partial oxidation; Petroleum; Reaction engineering; Reactors; Selectivity; Syngas; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2004.09.012

Model hydrocarbon mixtures ( n-octane + i-octane, n-decane + n-hexadecane, n-decane + naphthalene) were reacted with air over a rhodium-coated monolith in an effort to determine relative reactivities of various homologues in gasoline and diesel fuels. This information is required to determine the appropriate operating conditions for achieving maximum syngas yields from these fuels. We find that the overall reactivity of these fuel mixtures is not simply an average over the reactivities of constituent molecules. Results indicate that, whereas i-octane is more reactive than n-octane in the mixture at all C/O feed ratios, n-decane is more reactive than n-hexadecane in the mixture only at ratios leaner than the syngas stoichiometry (based on the mixture) and this trend reverses as the C/O feed ratio increases. Addition of 10 mol% naphthalene to n-decane successfully produces syngas in selectivities exceeding 70%. This demonstrates the ability of the rhodium-monolith reactor to partially oxidize a wide variety of hydrocarbon mixtures, including the hydrogen-deficient poly-aromatic compounds, to syngas and olefins without any evident deterioration in performance.