The overall BioReSteel objective is to develop and validate an innovative approach to producing and utilizing one type of biocoal based on renewable resources to replace the fossil carbon and natural gas, which are currently used in the electric arc furnace (EAF) steelmaking process.

BioReSteel solution uses and valorizes low-grade biomass from locally wide available wet biogenic residues (waste) for biocoal production, allowing the co-production of a phosphorus fertilizer from secondary resources.

BioReSteel intends to exploit abundant biomass residues (thus following the circular economy) and minimize the use of limited natural resources of fossil coal and natural gas (conservation of resources), thus contributing to a sustainable and low-carbon steelmaking.

Specific Goals

• Carbon footprint: a reduced fossil CO2 emission of about 2.5 Mt per year for the steel industry
• In the BioReSteel process the energy cost will be reduced by 30% when the fossil fuel (coal and natural gas) is substituted with 50% developed biocarbon.
• The minimum fixed carbon content in hydrochar after pyrolysis will be 80% on a dry and ash-free basis.
• Providing a procedure for the production of a solid inorganic macronutrient fertilizer complying with EU rules on fertilizing products (PE-CONS 76/18), especially with the maximum contaminant contents of Cd, Cr, Hg, Ni, Pb and As.
• Providing a procedure for the extraction and recovery of 95% of phosphorus from the developed biocarbon, and the remaining phosphorus content will be below 0.05% in the developed biocarbon produced from any biomass.
• The carbon yield in the steel bath by using developed biocarbon in EAF can reach 70%.
• A stable slag foaming with a completely covered arc can be achieved by using bio-briquettes. It can be evaluated by professional judgment.
• Effective utilization of mill scales for slag foaming in EAF by checking the metallic iron yield.

Method

The BioReSteel project connects the generation of wet biogenic residues with the production of suitable biocarbon for the EAF steelmaking. The project aims to integrate the following units of operation:

1. Hydrothermal treatment of wet biological residues with ash removal and phosphorus recovery.
2. Hydrochar thermal post treatment.
3. Biocarbon-iron oxides briquettes making.
4. Hydrochar (pristine and post-treated) EAF testing at pilot scale.
5. Hydrochar (pristine and post-treated) EAF testing at industrial scale.

Each unit brings a specific contribution in the conversion of residues to intermediate bioenergy carries and its applications for the steelmaking, but above all its their combination that allows the achievement of superior characteristics and process performances. The separate working principles of these units have been already experimentally observed at TRL 3 on specific streams and conditions. Within the BioReSteel project, the flexible conversion of biogenic residues to intermediate bioenergy carries through an integrated concept is advanced to TRL 5. This is done by validating the overall process in all its units, through the conversion of representative of different kinds of residues, to intermediate bioenergy carriers for the EAF steelmaking applications.

Environmental/ Social Impact

The BioReSteel project represents a great opportunity for the EU to reduce the environmental and social impact of both the organic waste value chain, and of fossil fuel (coal and natural gas) extraction and use. By producing solid fuels from biowastes, the BioReSteel project will contribute to the reduction in greenhouse gas emissions: the consortium estimates that the project will contribute to reduce GHG emissions due to the residues processing, transportation and disposal by more than 50% from two categories:

1. direct emissions that originate from waste management activities such as methane from landfills and CO2 emissions from transport, incineration and recycling plants;
2. avoided emissions, which represent the life cycle benefits from resource recovery (using waste as a secondary material or energy source) and replacing the use of virgin materials or fuels.

At the end users’ side, around 70 Mton steel is produced from EAF production route in Europe. By only switching coal to the developed biocarbon, the fossil CO2 reduction is estimated to be 2.5 Mton/year. In addition, around 900 Kton bio-based struvite fertilizer can be produced annually. Currently, the steel production from the EAF process is around 40% of the total steel production in Europe, therefore, in a long-term when the EAF steelmaking is dominate, the fossil CO2 reduction can be doubled, contributing to the fossil-free steelmaking industry and bio-based fertilizer for the agriculture.