Charcoal to replace black coal in Port Kembla steel trial

Coal is the source of carbon for most of the world's steelmaking and the industry will struggle to make massive carbon reductions until an alternative is found.

BlueScope has lodged a Major Projects modification application for the trial, which would be conducted with University of Wollongong researchers and the Australian Renewable Energy Agency's (ARENA) Future Fuels Cooperative Research Centre.

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The biochar would complement and reduce, rather than replace, coal in the steelmaking process.

ARENA announced on May 9 that it would give more than $900,000 to BlueScope to investigate options to reduce its carbon usage and emissions.

A BlueScope spokesman said testing had started already at UOW facilities.

"The trial has commenced, with supplies of biochar secured and initial testing to be conducted at the Bulk Materials Engineering [test] facility at the University of Wollongong, followed by plant trials using different ratios of biochar mixed with pulverised coal in the No.5 blast furnace," he said.

Biochar is charcoal, usually made from burning wood. BlueScope's application says it has acquired for the trial "two sources of sustainably sourced timber biomass" but does not specify further.

The steelmaker said introducing biochar at the Pulverised Coal Injection (PCI) stage as it would require a similar mass of biochar as of coal - about 1.1 tonnes of biochar to 1 tonne of coal.

"The PCI Plant is the ideal means of introducing biochar as a partial replacement of coal in the blast furnace process to significantly decrease net CO2 emissions from integrated steelmaking," the application states.

"Research has indicated that biochar has improved combustion characteristics when compared to coal. This could result in a lower overall blast furnace fuel rate or an increase in proportion of injected fuel relative to coke charged, in turn resulting in further net CO2 emissions reductions."

The Port Kembla Steelworks Renewables and Emissions Reduction Study funded by ARENA will explore two "pathways": smarter carbon usage, and direct carbon avoidance, and was expected to be complete by next June.

BlueScope had investigated using charcoal for steelmaking before but it had not progressed to action.

"Integrated steelmaking in its present-day form being inherently carbon-based will produce CO2 emissions and waste streams," BlueScope's application states.

"Given BlueScope has committed to continued investment in its current technology for integrated steelmaking up until well into the 2030s then CO2 emissions reductions will become integrated commensurately more difficult to achieve.

"Use of biochar as a PCI coal replacement offers one of the few means of significantly reducing the net CO2 emissions from a blast furnace."