September 22, 2010

Environmental Win for Alcoa

Reductions in carbon dioxide emissions and energy use, thanks to innovative new technology, have secured Alcoa a win at the 2010 WA Engineering Excellence Awards.

A new process, which took out top honours under the 'Environment' category, uses naturally occurring bacteria to consume oxalate - an impurity in the alumina refining process.

Oxalate removal is essential for high alumina quality and refinery productivity. The new process, known as 'continuous biological oxalate destruction', is an environmentally friendly solution to the oxalate challenge.

The development of the process, by Alcoa's global refining research and development division (Technology Delivery Group - TDG) based in Western Australia, was more than 10 years in the making.

Alcoa Vice President of Technology and Manufacturing Laurie Stonehouse said: “This is well deserved recognition for TDG. The biological destruction process has proven to be extremely robust technology, delivering well above design expectations.

“It's very unusual for a new technology to perform so well, so this is a real credit to TDG and all our people involved in the development work.”

The biological destruction process is currently in operation at Alcoa's Kwinana Refinery saving around 8,000 tonnes of carbon dioxide from going into the atmosphere each year, compared with alternative oxalate destruction techniques.

Alcoa is expected to roll-out the process to its other WA refineries at Pinjarra and Wagerup and then potentially to its refineries around the world.

Residue Technical Manager Dr David Cooling, who was at the core of the biological destruction process development, said: “This win is a real honour considering the other six quality submissions in our category including an advanced solar thermal initiative, the new Perth to Bunbury Highway, and the Great Northern Highway projects.”

Long-term, the process has the potential to consume all of the nearly 200 metric tonnes of oxalate removed each day by Alcoa's nine refineries around the world, while reducing both greenhouse gas emissions and energy usage.

As a category winner Alcoa is now eligible to enter the Engineers Australia National Awards, with the winners announced at Parliament House in Canberra on 24 November 2010.

Since 1968 Alcoa's TDG has been developing innovative new equipment and processes for cleaner, more efficient production at Alcoa refineries worldwide, and consistently helps to solve environmental challenges through new technology. TDG employs around 80 scientists, engineers, research and support staff.

- ENDS -

Background to Oxalate:
Oxalate is a natural product found in soil and some plants. When decaying plant matter is carried underground via water, some of it sticks to bauxite ore and enters the alumina refining process, where it degrades into oxalate. Considered an impurity, oxalate must be removed for the process to work efficiently and for the alumina to meet specification.

Background to Continuous Biological Oxalate Destruction:
The biological destruction process uses a series of tanks containing warm liquid and bacteria growing on plastic carriers. Oxygen and nutrients are added, and oxalate is introduced as a feed source. The bacteria consume the oxalate.

Media contact: Sarah Tempest 0404 800 417 sarah.tempest@alcoa.com.au