Formation of Metallurgical Coke within Minutes through Coal Densification and Microwave Energy

Williams, Orla; Ure, Alex; Stevens, Lee; Binner, Eleanor; Dodds, Chris; Kingman, Samuel; Das, Bidyut; Dash, Pratik Swarup; Lester, Edward

Abstract

This paper shows how feedstock densification gives rise to a step change in the time required to create a metallurgical grade coke using microwave energy. Five densified coking and non-coking coals were heated in a multi-mode microwave 2450 MHz cavity for varying treatment times (2-20 minutes) with a fixed power input (6 kW). Proximate analysis, intrinsic reactivity, coke reactivity, dielectric properties, and petrographic analysis of the coals and microwave produced lump cokes were compared to a commercial lump coke. Densifying the sample prior to microwave treatment enabled a dramatic acceleration of the coking process when combined with targeted high microwave energy densities. It was possible to form fused coke lump structures with only 2 minutes of microwave heating compared to 16-24 hours via conventional coking. Anisotropic coke morphologies (lenticular and circular) were formed from non-coking coal that are not possible with conventional coking and increasing treatment time improved overall coke reflectance. Three of the coals produced coke with equivalent coke reactivity index values of 20-30, which are in the acceptable range for blast furnaces. The study demonstrated that via this process, non-coking coals could potentially be used to produce high quality cokes, potentially expanding the raw material options for metallurgical coke production.

Citation

Williams, O., Ure, A., Stevens, L., Binner, E., Dodds, C., Kingman, S., Das, B., Dash, P. S., & Lester, E. (2019). Formation of Metallurgical Coke within Minutes through Coal Densification and Microwave Energy. Energy and Fuels, 33(7), 6817-6828. https://doi.org/10.1021/acs.energyfuels.9b00511

• Journal Article Type: Article
• Acceptance Date: Jun 16, 2019
• Online Publication Date: Jul 1, 2019
• Publication Date: Jul 18, 2019
• Deposit Date: Jul 2, 2019
• Publicly Available Date: Jul 2, 2020
• Journal: Energy & Fuels
• Print ISSN: 0887-0624
• Electronic ISSN: 1520-5029
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 33
• Issue: 7
• Pages: 6817-6828
• DOI: https://doi.org/10.1021/acs.energyfuels.9b00511
• Keywords: Fuel Technology; Energy engineering and power technology; General chemical engineering
• Public URL: https://nottingham-repository.worktribe.com/output/2257570
• Publisher URL: https://pubs.acs.org/doi/10.1021/acs.energyfuels.9b00511
• Additional Information: This document is the Accepted Manuscript version of a Published Work that appeared in final form in Energy and Fuels, copyright ©2019 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acs.energyfuels.9b00511
• Contract Date: Jul 2, 2019