Mechanistic insights of CO2-coke reaction during the regeneration step of the fluid cracking catalyst

Autor:	Yiu L. Lam, Thiana S. Gomes, Raphael S. Silva, Oscar René Chamberlain, Sônia M.C. Menezes, Pierre M. Esteves, Ricardo D.M. Pimenta, Fabiana M. Santos, Luciana Tavares dos Santos, Marcelo Maciel Pereira
Rok vydání:	2008
Předmět:	Chemistry Process Chemistry and Technology Kinetics chemistry.chemical_element Coke Heterogeneous catalysis Fluid catalytic cracking Catalysis Cracking chemistry.chemical_compound Chemical engineering Carbon dioxide Organic chemistry Carbon
Zdroj:	Applied Catalysis A: General. 336:40-47
ISSN:	0926-860X
Popis:	The regeneration of a coked fluid catalytic cracking (FCC) catalyst under O2/He and CO2/He atmospheres from room temperature up to 1000 °C was studied using online mass spectroscopy. The catalyst was also thermally treated at temperatures between 300 °C and 500 °C in order to promote coke modification. It was verified that the amount of aliphatic carbon decreased for higher temperatures. These treatments have a more significant impact on the coke-CO2 reaction than on the coke-O2 reaction. The former reaction was the focus of the present investigation and the results were compared to the latter reaction. CO2 preferentially reacts in the beginning of coke burning and a remarkable decrease of CO2 activity is observed with the calcinated coked catalyst. Regeneration under 13CO2/He at constant temperatures between 600 °C and 940 °C revealed a first-order kinetics for the coke-CO2 reaction. The CO2 molecule reacts dissociatively introducing oxygenated functionality into the coke. These species are decomposed at high temperature forming CO and no water is observed during the CO2-coke reaction.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::9c12aa1ff3d497d178d6ea69a7133556 https://doi.org/10.1016/j.apcata.2007.10.005 Zobrazit plný text záznamu Full Text from ScienceDirect