Our latest research paper: "Effect of Charcoal and Kraft-lignin Addition on Coke Compression Strength and Reactivity" has been published in Energies. The research investigates the possibility to replace part of the coking coal with charcoal or Kraft-lignin in metallurgical coke production.

Abstract: The aim of this research was to investigate the effects of charcoal and Kraft-lignin additions on the structure, cold compression strength, and reactivity of bio-cokes produced at the laboratory scale. Bio-cokes were prepared by adding charcoal and Kraft-lignin (2.5, 5.0, 7.5, and 10.0 wt %) to medium-volatile coal and coking the mixture with controlled heating rate (3.5 °C/min) up to 1200 °C. In addition, four particle sizes of charcoal were added with a 5 wt % addition rate to investigate the effect of particle size on the compression strength and reactivity. Thermogravimetric analysis was used to evaluate the pyrolysis behavior of coal and biomasses. Optical microscopy was used to investigate the interaction of coal and biomass components. It was found that by controlling the amount of charcoal and Kraft-lignin in the coal blend, the compression strength of the bio-cokes remains at an acceptable level compared to the reference coke without biomass addition. The cold compression strength of the charcoal bio-cokes was higher compared to Kraft-lignin bio-cokes. The reactivity of the bio-cokes with charcoal addition was markedly higher compared to reference coke and Kraft-lignin bio-cokes, mainly due to the differences in the physical properties of the parental biomass. By increasing the bulk density of the coal/biomass charge, the cold compression strength of the bio-cokes can be improved substantially.

Authors: H. Suopajärvi, E. Dahl, A. Kemppainen, S. Gornostayev, A. Koskela, T. Fabritius

Our latest research paper: "Charcoal Use in Chromite Pellets - Effect on Sintering Process, Pellet Properties, and Electrical Conductivity" has been published in Steel Research International. The research investigates the possibility to replace fossil coke with charcoal in chromite pellets.

Abstract:

Ferrochrome is produced by carbothermic reduction of chromite raw materials. Chromite fines need to be agglomerated before they can be utilized. Typically, chromite fines are fed to the smelting furnace in a form of sinter or sintered pellets. Sintering requires high temperatures, which is generated by burning carbon-bearing materials. Usually, coke is used as a fuel in chromite pellet sintering, which results in SOX and CO2 emissions. Using low-sulfur biofuel to substitute coke is an attractive technique for reducing SOX and CO2. In this paper, coke substitution with charcoal in chromite pellet sintering is studied. The results show that coke substitution with charcoal affects the sintering behavior, cold compression strength, and electrical conductivity of the chromite pellets. The suitable replacing proportion of charcoal according to studies made in this paper will be 50%.

Authors:

Sakaranaho M, Heikkilä A, Suopajärvi H, Päätalo M, Fabritius T

System Integrated Metals Processing: Final report available (link)

The main target of Show Case 4 – CARBO was to clarify the feasibility of using alternative reducing agents in the metallurgical processes to lower the carbon footprint of metal production without compromising product quality and efficient process operation. The main emphasis in Show Case 4 was placed on the use of biomass-based reductants, which are considered to be sustainable fuels due to their renewability. The prior knowledge concerning the use of biomass-based reductants in modern metallurgical processes is vague, which has restricted wider use of these reductants in the industry. In Show Case 4, the feasible physical and chemical properties of biomass-based reducing agents to be used in different metallurgical processes were investigated. New tools and methods to test the properties of reducing agents and to create new specifications for efficient use in metallurgical unit processes were developed. Economic and environmental synergies of several process integration opportunities were also evaluated in the project. As a result of the project, there is now a much better understanding of the limitations and opportunities in using biomass-based reducing agents in metallurgical unit processes. The project results shed light on the economic constraints and the possible CO2 emission reduction potential.

We will present our latest bio-coke research results in the European Steel Technology and Application Days in Vienna, Austria, 26-29 June (http://estad2017.org/).

Title: Evaluation of bio-coke strength and reactivity for blast furnace use

The focus of ESTAD:
The international conference focuses on the latest trends and issues and provides a wide networking and information platform for equipment and service suppliers, plant manufacturers and steelmakers. At this event you will acquire the latest information on new ideas and developments as well as on the state-of-the-art in metallurgical process technologies for iron and steel production, steel materials and steel application.

My latest review paper: "Extensive review of the possibilities to use biomass-based fuels in iron and steelmaking processes" has just been published in Journal of Cleaner production

Abstract:
Steel production is one of the most energy and carbon intensive industries contributing 5–7% of the global CO₂ emissions. In the search for ways to decrease fossil CO₂ emissions, biomass-based reducing agents are considered as one promising opportunity. This paper presents the results of a systematic literature review of technological possibilities and constraints, environmental performance and economical limitations of using biomass-based reducing agents in iron and steelmaking processes. The review indicates that biomass-based reducing agents could be applied in the main iron and steelmaking unit processes with varied fossil fuel replacement ratios. The greatest potential to replace fossil fuel is in the charcoal injection to the blast furnace. Life cycle emissions of steelmaking may be considerably lowered through biomass-based reducing agent use. The main constraint in facilitating the transition towards biomass-based steelmaking seems to be the high price of biomass and biomass-based reducing agents compared to fossil-based reducing agents. In the future, there is a need to develop simultaneously cross-industrial production platforms to produce biomass-based reducing agents and other, more valuable products from biomass. This would enhance the economic and environmental performance of producing steel with biomass-based reducing agents.