Life cycle assessment of renewable reductants in the ferromanganese alloy production: a review

peer-reviewedThis study examined the literature on life cycle assessment on the ferromanganese alloy production route. The environmental impacts of raw material acquisition through the production of carbon reductants to the production of ferromanganese alloys were examined and compared. The transition from the current fossil fuel-based production to a more sustainable production route was reviewed. Besides the environmental impact, policy and socioeconomic impacts were considered due to evaluation course of differences in the production routes. Charcoal has the potential to substantially replace fossil fuel reductants in the upcoming decades. The environmental impact from current ferromanganese alloy production can be reduced by ≥20% by the charcoal produced in slow pyrolysis kilns, which can be further reduced by ≥50% for a sustainable production in high-efficient retorts. Certificated biomass can ensure a sustainable growth to avoid deforestation and acidification of the environment. Although greenhouse gas emissions from transport are low for the ferromanganese alloy production, they may increase due to the low bulk density of charcoal and the decentralized production of biomass. However, centralized charcoal retorts can provide additional by-products or biofuel and ensure better product quality for the industrial application. Further upgrading of charcoal can finally result in a CO2 neutral ferromanganese alloy production for the renewable power supply

Charcoal as an alternative reductant in ferroalloy production: A review

peer-reviewedThis 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

A study of densified biochar as carbon source in the silicon and ferrosilicon production

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Electrical Resistivity of Carbonaceous Bed Material at High Temperature

This study reports the effect of high-temperature treatment on the electrical properties of charcoal, coal, and coke. The electrical resistivity of industrial charcoal samples used as a reducing agent in electric arc furnaces was investigated as a renewable carbon source. A set-up to measure the electrical resistivity of bulk material at heat treatment temperatures up to 1700 ∘C was developed. Results were also evaluated at room temperature by a four-point probe set-up with adjustable load. It is shown that the electrical resistivity of charcoal decreases with increasing heat treatment temperature and approaches the resistivity of fossil carbon materials at temperatures greater than 1400 ∘C. The heat treatment temperature of carbon material is the main influencing parameter, whereas the measurement temperature and residence time showed only a minor effect on electrical resistivity. Bulk density of the carbon material and load on the burden have a large impact on the electrical resistivity of each material, while the effect of particle size can be neglected at high heat treatment temperature or compacting pressure. The mechanical durability of charcoal slightly increased after heat treatment and decreased for coal and semi-coke samples. The results indicate that charcoal can be used as an efficient carbon source for electric arc furnaces

Renewable reducing agents for the use in ferroalloy industries : Doctoral Dissertation for the Degree Philosophiae Doctor (PhD) at the Faculty of Engineering and Science, Specialisation in Renewable Energy

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Densification of Biocarbon and Its Effect on CO2 Reactivity

Charcoal is an interesting reducing agent because it is produced from biomass which is renewable and does not contribute to global warming, provided that there is a balance between the felling of timber and growth of trees. Biocarbon is a promising alternative to fossil reductants for reducing greenhouse gas emissions and increasing sustainability of the metallurgical industry. In comparison to conventional reductants (i.e., petroleum coke, coal and metallurgical coke), charcoal has a low density, low mechanical properties and high CO2 reactivity, which are undesirable in ferroalloy production. Densification is an efficient way to upgrade biocarbon and improve its undesirable properties. In this study, the deposition of carbon from methane on three types of charcoal has been investigated at 1100 °C. CO2 reactivity, porosity and density of untreated and densified charcoal were measured, and results were compared to metallurgical coke. Surface morphology of the charcoal samples was investigated by using scanning electron microscopy (SEM). SEM confirmed the presence of a deposited carbon layer on the charcoal. It was found that the CO2 reactivity and porosity of charcoals decreased during the densification process, approaching that of fossil fuel reductants. However, the CO2 reactivity kept higher than that of metallurgical coke

Densification of Biocarbon and Its Effect on CO2 Reactivity

Charcoal is an interesting reducing agent because it is produced from biomass which is renewable and does not contribute to global warming, provided that there is a balance between the felling of timber and growth of trees. Biocarbon is a promising alternative to fossil reductants for reducing greenhouse gas emissions and increasing sustainability of the metallurgical industry. In comparison to conventional reductants (i.e., petroleum coke, coal and metallurgical coke), charcoal has a low density, low mechanical properties and high CO2 reactivity, which are undesirable in ferroalloy production. Densification is an efficient way to upgrade biocarbon and improve its undesirable properties. In this study, the deposition of carbon from methane on three types of charcoal has been investigated at 1100 °C. CO2 reactivity, porosity and density of untreated and densified charcoal were measured, and results were compared to metallurgical coke. Surface morphology of the charcoal samples was investigated by using scanning electron microscopy (SEM). SEM confirmed the presence of a deposited carbon layer on the charcoal. It was found that the CO2 reactivity and porosity of charcoals decreased during the densification process, approaching that of fossil fuel reductants. However, the CO2 reactivity kept higher than that of metallurgical coke

Life cycle assessment of renewable reductants in the ferromanganese alloy production: a review

This study examined the literature on life cycle assessment on the ferromanganese alloy production route. The environmental impacts of raw material acquisition through the production of carbon reductants to the production of ferromanganese alloys were examined and compared. The transition from the current fossil fuel-based production to a more sustainable production route was reviewed. Besides the environmental impact, policy and socioeconomic impacts were considered due to evaluation course of differences in the production routes. Charcoal has the potential to substantially replace fossil fuel reductants in the upcoming decades. The environmental impact from current ferromanganese alloy production can be reduced by ≥20% by the charcoal produced in slow pyrolysis kilns, which can be further reduced by ≥50% for a sustainable production in high-efficient retorts. Certificated biomass can ensure a sustainable growth to avoid deforestation and acidification of the environment. Although greenhouse gas emissions from transport are low for the ferromanganese alloy production, they may increase due to the low bulk density of charcoal and the decentralized production of biomass. However, centralized charcoal retorts can provide additional by-products or biofuel and ensure better product quality for the industrial application. Further upgrading of charcoal can finally result in a CO2 neutral ferromanganese alloy production for the renewable power supply