Charcoal as an Alternative Reductant in Ferroalloy Production: A Review

Abstract

This paper provides a fundamental and critical review of biomass application as renewable reductant in integrated ferroalloy reduction process. The basis for the review is based on the current process and product quality requirement that bio-based reductants must fulfill. The characteristics of different feedstocks and suitable pre-treatment and post-treatment technologies for their upgrading are evaluated. The existing literature concerning biomass application in ferroalloy industries is reviewed to fill out the research gaps related to charcoal properties provided by current production technologies and the integration of renewable reductants in the existing industrial infrastructure. This review also provides insights and recommendations to the unresolved challenges related to the charcoal process economics. Several possibilities to integrate the production of bio-based reductants with bio-refineries to lower the cost and increase the total efficiency are given. A comparison of challenges related to energy efficient charcoal production and formation of emissions in classical kiln technologies are discussed to underline the potential of bio-based reductant usage in ferroalloy reduction process.

Life Cycle Assessment of Renewable Reductants in the Ferromanganese Alloy Production: A Review

“…However, the inferior mechanical and chemical properties of bio-coke and charcoal hamper the direct replacement of metallurgical coke [55]. Most likely, metallurgical coke will be partly replaced by bio-coke in the shortterm [17] and by tailor-made charcoal in the long-term [15]. Other technologies, such as electrolytic manganese metal production, COREX ® or FINEX ® in combination with renewable reductants may also provide a CO 2 neutral production route as an alternative to the SAF [56,57].…”

“…Charcoal in Africa and Asia is often produced in earthmound kilns and pits at a low efficiency (batch processes), whereas charcoal in industrialized countries is produced in continuous retorts with by-product utilization [13][14][15]79]. Classical charcoal production results in the emission of incomplete combusted volatile matter, such as particulate matter, volatile organic carbon, organic acids, or polycyclic aromatic hydrocarbons (PAHs) [86,92], which are considered hazardous to health and environment [93,94].…”

“…However, not all aspects of sustainability can be considered within LCA [11]. Technical issues caused by the different properties and the economics of renewable reductants can play a significant role in replacing fossil fuel-based reductants [14,15]. In addition, renewable reductants may require more energy for handling and transport.…”

Metallurgical Coke Production with Biomass Additives: Study of Biocoke Properties for Blast Furnace and Submerged Arc Furnace Purposes

“…In EAF, bio-based materials can perform the function of a conventional carbon source, namely, carburize the steel or create foaming slag to improve the energy efficiency of the melting process [ 14 ]. In the SAF process, bio-based materials can be used as bio-reductants in the production of ferroalloys [ 15 ]. The possibility of using alternative reducing agents in the production of ferroalloys is becoming more and more relevant and is presented in references [ 10 , 15 , 16 , 17 ].…”

Special Issue: Biochemical and Thermochemical Conversion Processes of Lignocellulosic Biomass Fractionated Streams

“…This Special Issue points at several possibilities to integrate the production of bio-based reductants in ferroalloy industries with bio-refineries to lower the cost and increase the total efficiency. Despite challenges related to energy-efficient charcoal production and formation of air pollutions in classical biochar kilns, the potential of bio-based reductant usage in ferroalloy reduction process was underlined as a sustainable pathway to convert forestry to value-added products in metallurgical industries [24]. In addition, the mechanical durability of biochar slightly increased after heat treatment, whereas coal and semi-coke-based reductants showed a decrease in durability.…”