Food manufacturer improves sustainability with biogas recovery

Food manufacturing specialist Wiley has designed and constructed an innovative biogas and water treatment plant for JBS Australia. The innovation has resulted in improved sustainability and a reduced carbon footprint for the meat processing company.

The JBS Dinmore facility in the Queensland suburb of Ipswich processes 1675 beef cattle per shift and employs 1950 staff. Processing such a large volume of meat and by-products requires a significant amount of energy.

Prior to the project, the wastewater treatment plant (WWTP) comprised four anaerobic lagoons (ALs) whose primary function was the removal of organic material suspended in the wastewater. There were also four natural gas-fired boilers on site producing steam for hot-water production and rendering operations.

Wiley was contracted to design, install and commission a more efficient effluent treatment system to capture and re-use biogas released by the anaerobic digestion as an on-site renewable energy source. The project is claimed to be the first of its kind in the Australian red meat processing industry to retrofit an existing WWTP.

The project’s key solutions included:

• Construction of a 20 ML covered anaerobic lagoon (CAL);
• Covering of two existing anaerobic lagoons (AL) with high-density polyethylene (HDPE) to capture biogas, and then burn the gas through the boiler to provide energy for the plant;
• Installation of a biogas train to pipe biogas from the CALs to a central flare and then to the existing 10 MW boiler;
• Upgrade of WWTP with a new dissolved air flotation (DAF) unit.

The wastewater treatment system was improved through the installation of new pre-treatment equipment combined with CAL technology to optimise the generation of biogas for combustion in the existing natural gas-fired boiler plant which was modified to burn biogas.

The existing WWTP pre-treatment system was also improved by installing a new DAF unit. The DAF removes organic solids (waste fats, oils and greases, referred to as FOGs) which currently pass through the pre-treatment system and into the ALs.

The DAF unit regulates the inclusion of FOGs in the wastewater that passes into the new CALs. The ability to regulate FOGs inclusion rates is essential to optimising biogas generation from the CALs.

Two of the four existing ALs were fitted with high density polyethylene (HDPE) covers to enable the capture of biogas. The remaining two uncovered ALs were decommissioned and a new covered anaerobic lagoon (CAL) with a capacity of 20 ML was constructed.

Following construction of the CALs, a biogas train was installed to pipe biogas from the CALs to a central flare and the existing 10 MW boiler for co-combustion with natural gas. This required a new burner and control system for the boiler that would automatically prioritise the use of biogas over natural gas.

The result has led to not only an improved waste management system but also an 89% reduction in the facility’s annual greenhouse gas emissions and a saving of more than $1 million a year on natural gas costs.

Wiley was additionally recognised for its efforts at the Queensland Master Builders Association (QMBA) Brisbane Regional Awards, receiving the award for Innovation in Environmental Management Construction.

“This is an industry benchmark, demonstrating the reality of environmental processing solutions for heavy-emission producers.” said Graham Harvey, Wiley project director.

The technology and processes deployed as part of this project will provide addition learnings that will be applied across other JBS meat processing facilities in Australia of similar scale and nature. The project is both replicable and scalable within the red meat processing industry and other food processing industries that have a biological waste stream and a need to offset on-site energy requirements for heat and/or power generation.