Anonymous Leading Cereal Manufacturer

A leading Australian cereal manufacturer faced mounting pressure from rising energy costs and the environmental burden of organic waste disposal. The facility generated significant volumes of oat husks as a byproduct of cereal production — waste that required costly transport and gate fees to remove. With no onsite energy recovery system in place, the plant remained entirely dependent on grid electricity, leaving it exposed to price volatility. The manufacturer needed to design, build, and commission an anaerobic digestion plant capable of converting this organic waste stream into usable energy, reducing both operating costs and environmental impact.

Auto Control Systems (ACS), a Rockwell Automation Silver System Integrator based in Perth, developed the automation and control system for the anaerobic digestion plant. The solution centered on the Allen-Bradley CENTERLINE 2500 IEC Low Voltage Motor Control Center (MCC), which provided high-level motor control with Ethernet connectivity and ArcShield arc-fault protection. An Allen-Bradley CompactLogix PLC managed all process control across the four-stage digestion sequence — hydrolysis, acidogenesis, acetogenesis, and methanogenesis — while PowerFlex 525 and 753 AC drives delivered variable-speed flexibility. FactoryTalk View SE provided real-time process visibility with SMS alarming, and PlantPAx DCS process object libraries reduced engineering overhead. The control system was pre-built and tested in Perth as a containerised, scalable package before being transported to site.

The anaerobic digestion plant was successfully commissioned and is actively producing biogas from oat husk waste. At the time of reporting, produced gas was being flared while the facility moved toward full operational status. When fully operational, the plant is projected to deliver:

• 1.5 MW of combined electricity and heat generation
• 100% offset of the plant's existing energy requirements
• Surplus electricity available for export to the grid

The project also positions the manufacturer to monetise carbon credits under Australia's Clean Energy Futures Scheme and eliminate ongoing waste transport and disposal costs — converting a cost centre into an energy asset.

• Organic waste streams are viable energy feedstocks: Food manufacturers producing high volumes of agricultural byproducts (husks, pomace, whey) should assess anaerobic digestion as a path to energy self-sufficiency.
• Containerised, pre-tested control systems reduce site commissioning risk: Building and validating the automation package offsite compresses installation timelines and catches integration issues early.
• Scalable architecture matters for phased projects: Selecting a platform like PlantPAx that supports incremental expansion allows capacity to grow without redesigning the control layer.
• Compliance-ready hardware simplifies regulatory approval: Choosing equipment already aligned to emerging standards (AS/NZS 61439) avoids costly retrofits as mandates take effect.
• Continuous process control is non-negotiable: Anaerobic digestion requires constant pH and temperature monitoring — robust SCADA with remote access and alarming is essential, not optional.