Selective low temperature chemical looping combustion of higher alkanes with Cu- and Mn- oxides

Güleç, Fatih; Meredith, Will; Sun, Cheng-Gong; Snape, Colin E.

Abstract

Chemical looping combustion (CLC) of n-hexadecane and n-heptane with copper and manganese oxides (CuO and Mn2O3) has been investigated in a fixed bed reactor to reveal the extent to which low temperature CLC can potentially be applicable to hydrocarbons. The effects of fuel to oxygen carrier ratio, fuel feed flow rate, and fuel residence time on the extent of combustion are reported. Methane did not combust, while near complete conversion was achieved for both n-hexadecane and n-heptane with excess oxygen carrier for CuO. For Mn2O3, complete reduction to Mn3O4 occurred, but the extent of combustion was controlled by the much slower reduction to MnO. Although the extent of cracking is relatively small in the absence of cracking catalysts, for the mechanism to be selective for higher hydrocarbons suggests that the reaction with oxygen involves radicals or carbocations arising from bond scission. Sintering of pure CuO occurred after repeated cycles, but this can easily be avoided using a support, such as alumina. The fact that higher hydrocarbons can be combusted selectively at 500 °C and below, offers the possibility of using CLC to remove these hydrocarbons and potentially other organics from hot gas streams.

Citation

Güleç, F., Meredith, W., Sun, C., & Snape, C. E. (2019). Selective low temperature chemical looping combustion of higher alkanes with Cu- and Mn- oxides. Energy, 173, 658-666. https://doi.org/10.1016/j.energy.2019.02.099

• Journal Article Type: Article
• Acceptance Date: Feb 13, 2019
• Online Publication Date: Feb 15, 2019
• Publication Date: Apr 15, 2019
• Deposit Date: Feb 18, 2019
• Publicly Available Date: Feb 18, 2019
• Journal: Energy
• Print ISSN: 0360-5442
• Electronic ISSN: 1873-6785
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 173
• Pages: 658-666
• DOI: https://doi.org/10.1016/j.energy.2019.02.099
• Keywords: CO2 capture; Chemical looping combustion (CLC); Liquid fuels; Copper-based oxygen carrier; Manganese-based oxygen carrier
• Public URL: https://nottingham-repository.worktribe.com/output/1562149
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0360544219302981
• Contract Date: Feb 18, 2019