Evaluation of demineralized lignin and lignin-phenolic resin blends to produce biocoke suitable for blast furnace operation

Castro-Díaz, Miguel; Vega, María Fernanda; Musa, Umaru; Díaz-Faes, Elvira; Barriocanal, Carmen; Snape, Colin

Abstract

Metallurgical coke makers could reduce carbon emissions and material costs by introducing waste lignin in coke oven charges. Two approaches have been studied here to increase the use of lignin in the preparation of metallurgical coke: lignin demineralization with H2SO4 and lignin blending with a low rank coal using phenolic resin as binder. The biocoke obtained after carbonization at 1000 °C from the hydrochar of demineralized lignin (350 °C, 6 h, biomass/water = 0.5 wt/wt) had much higher reactivity than the coke obtained from the low rank coking coal, proving that demineralization of lignin prior hydrothermal conversion is not a valid route for biocoke making. In the other approach, it was found that blends containing 70 wt% low rank coal, 24 wt% torrefied lignin (before or after demineralization) and 6 wt% phenolic resin produced biocokes with suitable mechanical strength for handling but higher reactivity than the coke obtained from the low rank coking coal alone. The microporous surface areas of the biocokes studied did not correlate with their reactivity values.

• Journal Article Type: Article
• Acceptance Date: Aug 29, 2019
• Online Publication Date: Sep 3, 2019
• Publication Date: Dec 15, 2019
• Deposit Date: Sep 10, 2019
• Publicly Available Date: Sep 4, 2020
• Journal: Fuel
• Print ISSN: 0016-2361
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 258
• Article Number: 116125
• DOI: https://doi.org/10.1016/j.fuel.2019.116125
• Keywords: Kraft lignin, demineralization, torrefaction, phenolic resin, biocoke
• Public URL: https://nottingham-repository.worktribe.com/output/2598810
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0016236119314796?via%3Dihub