COHRAL produces biogas for Oakey Abattoir

Oakey Abattoir, located on Queensland’s Darling Downs, has launched an initiative to extract green energy biogas from its wastewater streams with the COHRAL covered high rate anaerobic lagoon. Energy generated by the anaerobic digestion plant will replace the millions of dollars worth of natural gas currently consumed by the abattoir.

Designed by Global Water Engineering (GWE), the plant will simultaneously reduce the plant’s carbon footprint and produce wastewater far cleaner than typical waste lagoons.

According to Oakey Abattoir General Manager Pat Gleeson, once the plant has repaid its cost of construction through gas purchase savings (expected to take less than five years), it will then continue to deliver benefits and profitability far into the future. It was installed by environmental engineering and green energy firm CST Wastewater Solutions.

COHRAL technology - which is suitable for both livestock and cropping operations - uses concentrated anaerobic bacteria to digest 70% of the organic matter (COD, or chemical oxygen demand) in Oakey’s wastewater to produce effluent of a far-higher quality than typical open lagoons.

The technology was adopted after an exhaustive selection process conducted by Oakey and its owner, Nippon Meat Packers. The Oakey Abattoir, which employs 750 people, adheres to Nippon Meat Packers’ strict environmental guidelines and corporate responsibility ethic as a major operator across Australia and exporter to 34 countries.

According to the company, the technology can turn an environmental problem into profit by simultaneously enhancing water quality and lowering fuel bills. “Importantly, it helps us to guard against future price rises in the cost of energy and imposts such as a carbon tax,” Gleeson said.

Minister Ian Macfarlane (right) performs the launch ceremony, congratulating Pat Gleeson (centre), Oakey’s General Manager and Michael Bambridge (left), Managing Director of CST Wastewater Solutions.

Another benefit of covered anaerobic lagoons is that the methane biogas produced within them is not only prevented from escaping into the atmosphere (where it is many times more damaging than C0₂ emissions) but is also harnessed to generate energy - rather than wastewater being a heavy consumer of energy in processing and oxygenation.

The Oakey plant will feature re-use of the biogas in its boilers, where it is initially expected to replace usage of about 50,000 gigajoules of natural gas each year.

While GWE’s anaerobic wastewater technology has been proven worldwide at more than 300 installations of totally enclosed tanks or reactors, this is the first time it has been applied to a covered lagoon, an application where it has enormous further potential in countries with strong agribusiness sectors.

“In addition to the obvious waste-to-energy benefits, the process also helps curb odours that emanate from open lagoons in processing plants,” said CST Wastewater Solutions’ Managing Director Michael Bambridge. “This is becoming a much bigger issue in Australia as urban encroachment means agribusiness and expanding communities are located much closer to each other than previously.

“So instead of open lagoons being potential dumping grounds for environmental problems, closed installations such as Oakey Creek’s represent an outstanding contribution to good community relations.

“Yet another outstanding benefit is that anaerobic digestion produces reliable and predictable base-load power - unlike some other green-energy technologies, it is not dependent on the wind blowing or the sun shining.

“The environmental and cost benefits of COHRAL technology as deployed by Oakey Abattoir are outstanding and something we expect to attract world attention for agribusiness, including meat, dairy and crop waste processing.”

The COHRAL lagoon was officially launched on 7 March by Minister for Industry Ian Macfarlane.