Functionalized graphene sheet as a dispersible fuel additive for catalytic decomposition of methylcyclohexane

• Published in: Combustion and flame Vol. 217; pp. 212 - 221
• Main Authors: Sim, Hyung Sub, Yetter, Richard A., Hong, Sungwook, van Duin, Adri C.T., Dabbs, Daniel M., Aksay, Ilhan A.
• Format: Journal Article
• Language: English
• Published: New York Elsevier Inc 01-07-2020; Elsevier BV
• Subjects: Computer simulation; Decomposition; Dehydrogenation; Endothermic reactions; Fuel additive; Fuel additives; Functional groups; Functionalized graphene sheets; Graphene; Jet fuel; Methylcyclohexane; Molecular dynamics; Nuclear fuels; Reaction mechanisms; Supercritical conditions; Supercritical conditions; Fuel additive; Jet fuel; Endothermic reactions; Functionalized graphene sheets
• ISSN: 0010-2180; 1556-2921
• DOI: 10.1016/j.combustflame.2020.04.002

The decomposition of methylcyclohexane (MCH) containing suspended functionalized graphene sheets (FGS) was studied using a high-pressure flow reactor, under supercritical conditions over the temperature range of 780 – 825 K at a constant pressure of 4.72 MPa. Experiments showed both fuel conversion rates and C1-C2 product yields were increased by 43.3% and 62.1%, respectively, with the addition of 50 ppmw of FGS at 820 K. The reaction mechanisms between hydrocarbon and FGS were computationally investigated using reactive molecular dynamics (MD) with ReaxFF force fields at the temperatures of 1700, 1800, and 1900 K. The MD simulations revealed that oxygen-containing functional groups attached to the FGS plays an important role in catalyzing the decomposition of the fuel. Heterogeneous dehydrogenation of MCH into a C7H13 radical intermediate led to formation of secondary and tertiary radicals, such as H, CH3, and C2H5, during early extents of reaction promoting additional fuel-consuming steps, including H-abstraction and hydrogenation.