Abstract:
Metallurgical coke (met coke) is a fundamental raw material used in producing steel. Nevertheless, global warming has provoked a review of the role of coke oven plants, as greenhouse gas (GHG) emissions can be in the range of 1.8-2.3 kg CO2/kg steel. Even so, in 2052 carbon capture technologies and raw material substitution will have equivalent participation to that of greener processes (15% each), whereas conventional processes will still correspond to 40% of global steel production. Because of that, studying substitute materials in met coke production has become increasingly important. A lot has been made in testing plastics, wood chips, sawdust, residual tar, oil waste, pulverized coal, charcoal, and others; from these, only plastics and tar have been tested successfully in industrial scale, with substitution rates around 1% w/w (dry basis). In Brazil, challenges in implementing these processes in industrial scale include lack of research funding, availability of raw materials, logistics, and materials handling. Aside from the mentioned materials, sugar cane residues (straw, molasses, and bagasse) could be used, as they are abundant and could mitigate logistics and availability issues while reducing Scope 2 emissions. Furthermore, gas treatment issues need to be studied from industrial trials. To do so, the addition of a briquetting or stamp charging facility should enable proper, homogenous blending of raw materials before being fed to the coke ovens, which could tackle the materials handling issue, and allow industrial-scale testing and operation to be carried out.