The metallurgical industry faces increasing pressure to reduce the net emissions of greenhouse gases from the production of metals. Bioenergy is one solution that may iron out the excess, and increase the industry’s energy efficiency.

Led by CSIRO researchers and the Centre for Sustainable Resource Processing (CSRP), the ‘CO2 breakthrough in metal production program’ aims to develop breakthrough technologies, that enable step change [more than 10 per cent] reductions in net greenhouse gas emission in metal production.

The program will identify and develop specific opportunities for the successful use of biomass in the metal production industry, in which biomass energy is a technically sound and economically viable alternative to the use of fossil carbon, and is sourced in ways that are ecologically sound and acceptable to the community.

Program Leader Dr Sharif Jahanshahi from the CSIRO said “Our studies have shown that partial replacement of fossil carbon by bio-char over the next decade or two will create a demand for biomass supply of up to ten million tonnes per year.”

The aim of the CSRP is to create new methods to produce minerals and metals in a way that benefits the community, the environment and industry. It is a vision of sustainable minerals processing and metals production that will satisfy the global material needs of society with significantly reduced ecological impacts.

To achieve these aims, CSRP works to find technical solutions for progressively eliminating waste and emissions in the materials cycle, while enhancing business performance and meeting community expectations. The program will also develop viable technology options for recovery of high grade thermal energy from molten metallurgical slags, conversion of byproduct slag into a valuable material for production of ‘green cement’, and utilisation of recovered energy. As iron making is a significant contributor to greenhouse gas emissions, CSRP’s research has focussed heavily on iron and steel, however other minerals and metals are also being studied.

Biomass in the iron steel industry

The ‘Biomass in the iron steel industry’ project aims to identify, evaluate and demonstrate specific opportunities for the use of biomass in integrated steel making and electrical arc furnaces and assist with their possible implementation in OneSteel and BlueScope operations. By consolidating the information on biomass use in iron and steel making from the open literature with information from the companies’ internal reports and on site plant reviews, the project will identify and prioritise specific opportunities.

The CSRP 2007 – 08 annual report states that to date, a number of site visits have been made, during which data on biomass generation and usage was collected and documented. Progress was also made in the development and commissioning of a TGA (thermogravimetric analysis) apparatus to investigate the kinetics of pyrolysis reactions.

The ‘Biomass 2: the utilisation of carboneous waste in metallurgical processes’ project sought to address the large amounts of waste biomass produced annually in rural and regional Australia in the agricultural, forestry, sewage and waste treatment industries.

The mid-north region of South Australia was selected for a pilot study due to its proximity to timber and wood milling industries, and an “established and diversifying” agricultural industry. A visit was made to waste biomass producers.

The samples collected were treated in a kilogram scale pyrolysis rig. Researches concluded that the success of this project will require increased awareness on the part of biomass waste producers and potential customers of the benefits of this approach to biomass waste utilisation.

Dr Jahanshahi said the innovative challenge is to find viable solutions that capture the inherent sustainability opportunities associated with the use of biomass char and other forms of renewable, recycled or waste carbon.