Catalytic Cracking Reaction of Heavy Oil in the Presence of Cerium Oxide Nanoparticles in Supercritical Water

Energy Fuels, 2013, 27 (8), pp 4624–4631, DOI: 10.1021/ef400855k, Publication Date (Web): July 19, 2013
Catalytic Cracking Reaction of Heavy Oil in the Presence of Cerium Oxide Nanoparticles in Supercritical Water
Mehdi Dejhosseini †‡, Tsutomu Aida , Masaru Watanabe §, Seiichi Takami ‡, Daisuke Hojo #, Nobuaki Aoki #, Toshihiko Arita ‡, Atsushi Kishita , and Tadafumi Adschiri *‡#
ajiri@tagen.tohoku.ac.jp
† Graduate School of Engineering, Tohoku University, 6-6 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579, Japan
‡ Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
§ Research Center of Supercritical Fluid Technology, Tohoku University, 6-6-11 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579, Japan
Department of Environmental Science and Technology, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8579, Japan
# World Premier International Research Center-Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
Abstract
Researchers conducted catalytic cracking of Canadian oil sand bitumen in supercritical water to understand the effect of CeO2 nanoparticles. They conducted cracking at 723 K to promote a redox reaction between the water, bitumen, and catalyst for the production of hydrogen and oxygen. CeO2 with two distinct morphologies was used as the catalyst, since the redox reaction of CeO2 with water and organics is expected and its activity can be controlled by its structure. The two roles of water were considered as well.
Water is attractive as a high potential medium with low dielectric constant and density at near the critical point, enabling formation of highly crystalline smaller metal oxides particles. However, the chemical effects of water were studied with heavy oil catalytic cracking. Transmission electron microscopy images indicated that CeO2 nanoparticles with cubic and octahedral shape were synthesized using a plug-flow reactor under hydrothermal conditions.
The particles sizes were 8 and 50 nm for cubic and octahedral CeO2, respectively. Researchers noted that at 773 K the oxygen storage capacity (OSC) of the cerium oxide nanoparticles with cubic {100} facets was nearly 3.4 times higher than that of the cerium oxide nanoparticles with octahedral {111} facets. Heavy oil fractions of bitumen were cracked in a batch-type reactor at 723 K in order to produce as much light oil as possible. The effect of the catalyst loading and reaction conditions on the conversion rate and coke formation were investigated.
Full Text Source (Subscription or Fee): http://pubs.acs.org/doi/abs/10.1021/ef400855k