As the world continues to grapple with the challenges of combatting climate change one of its most reliable power sources has increasingly been maligned as a large culprit in contributing to the problem.

Still, time and time again, studies around the world have suggested that even with advances in renewables and alternative energy generation technologies, coal will continue to play a vital role in the world’s energy production into the future.

This knowledge has spurred the Australian coal industry to muster its efforts behind a global effort to develop low-emissions technology for coal-fired power stations.

In March, the curtains were drawn on the world’s first industrial scale (30mW electrical output) demonstration of a technology known as Oxyfuel.

Giving new life to the closed-down Callide A coal-fired power station in central Queensland, the technology was retro-fitted to the plant, achieving 10,000 hours of oxy-combustion and more than 5500 hours of carbon capture, signalling a major milestone on the road to commercial application of the technology.

The technology used conventional methods for power generation from coal, albeit with a few key differences.

“Essentially the way it works is that we start up a coal-fired boiler in the normal way, get it all up and running, and then we start to reduce the air going in and we start to recycle some of the actual flue (waste) gas which normally just goes straight up the stack,” Oxyfuel project director Dr Chris Spero explained.

“Into that recycled gas stream we inject oxygen from the air separation units where nitrogen has been stripped out.

“The key thing about this process modification is that we use exactly the same amount of coal and oxygen but the difference is: because the nitrogen has been pulled out - the amount of flue gas that goes up the chimney stack is a bit under 1/3 [of traditional amounts].”

The resulting concentrated amounts of carbon dioxide were then captured from the station, some of it going to the CO2CRC, a collaborative carbon capture and storage research organisation which used the gas to test how it affected deep rock formations in the Otway Basin when injected and stored.

Costing $245 million over its near three-year life, the project was put together by a joint venture between station owner CS Energy, the Australian Coal Association Low Emission Technologies company (ACALET), Glencore, Schlumberger Carbon Services, and Japanese participants JPower, Mitsui and IHI.

The Australian government contributed $63 million through its Low Emissions Technology Demonstration fund, while the Queensland government contributed $10 million.

Other funding, coming from the Japanese companies behind some of the oxyfuel technology as well as others amounted to $95 million, while the Australian coal industry at large sunk $76.9 million through its ACALET-operated Coal21 fund.

The Coal21 fund was established in 2006 through what was then the Australian Coal Association, to finance the pre-commercial demonstration work needed to develop key technologies for the industry.

The ACA, which has since rolled into the Minerals Council of Australia, established the fund based on a voluntary levy and has contributed funds to a long list of projects.

“It was recognised that the whole question of greenhouse gas emissions from coal use in any form - but most immediately power generation – was really an industry-wide issue,” ACALET deputy director technology Jim Craigen said.

“It’s not for any one coal company as a fuel supplier to try and find solutions. An industry-wide issue requires an industry-wide approach.

“The Coal21 fund was used as a vehicle by which nearly all the coal companies agreed to contribute funding according to their production. So the bigger guys pay more than the little guys.

“It’s a 20c per tonne levy on saleable coal and that’s under a series of voluntary agreements.

“So each individual coal producer - and in some cases that goes right down to individual mines - entered into a contractual agreement to pay this 20c per tonne which then creates the fund which enables us to invest in these projects on their behalf.”

With no government intervention or legislation forcing the industry’s hand, the Coal21 fund is unique in the world as far as ACALET is aware.

“It’s a global issue therefore we need global solutions,” Craigen said.

‘Australia is a relatively small nation with a small economy, so we’re certainly not going to solve the world’s problems all on our own, but we are making a contribution to that global effort and I would suggest that Australia, not just in coal but in renewables and all that other stuff as well, we’re punching well above our weight.”

Since its inception, Coal21 has contributed more than $300 million to a range of coal-related projects throughout the country.

Following the close of the Oxyfuel project the big job of consolidating all the data gained has begun.

A technical manual will be produced as a result, covering the project and analysing and assessing the results.

The JV partners are looking for commercialisation opportunities for the technology both domestically and overseas, with some of the Japanese participants looking to take the next step up in scale through projects in North America.

“Our project has helped create a pathway for the design and construction of larger scale oxy-combustion plants with carbon capture, as both bolt-on technology to existing plants and as new-build plants,” project director Spero said.

“The future for this technology is very exciting.”

Not wanting to let the equipment used at Callide go to waste, the JV has begun approaching other projects to see how the infrastructure could be used again.

“A number of organisations are looking at going the next step in clean coal and we have indicated to them that our equipment is available for re-use on those projects,” Spero said.

“The intent is not to try and profit out of it, it’s just we don’t want the equipment to be wasted. We’d like to see the equipment now being reused to further other projects.

“As an example, we have had discussions and made representations to the Collie hub carbon capture and storage project in Western Australia.

“We’re not directly involved but we’ve sent them detailed information about what equipment we have available and we’ve invited them to consider the suitability of some of that equipment for their own projects should they get to financial close. And we’ve done that with others as well.”

According to Spero, the work done at Callide will most likely prove to be a game-changer for any consideration of coal-fired power plants in Australia in the future.

“They would be capture-ready, there would be some features that would be incorporating the learnings from this technology,” he said.

“I don’t think we’ll be able to look at coal-fired power generation in quite the same way that we have been.”