Maximising the use of agricultural by-products reduces waste and improves sustainability. Other advantages include reducing a business’s environmental impact and maximising an important profit opportunity. Thus, farm Roana invested in a biomass automation plant that utilises livestock manure and other organic waste to generate energy.
To automate its processes, the farm wanted an advanced control network for monitoring the anaerobic digestion process and enhancing productivity. They chose CC-Link IE Field as their preferred solution. It connects to a range of Mitsubishi Electric automation devices and delivers Gigabit open Ethernet performance.
The farm is home to around eleven hundred water buffaloes. Each day, they provide over 3 tonnes of milk used to produce buffalo mozzarella cheese. Along with the product, the herd produces approximately 60 m3 of usable livestock manure per day. Importantly, before becoming agricultural fertilizer, it also produces bioenergy. The farm aimed to use this by-product to have a positive environmental impact by generating increased revenue for the business.
The anatomy of Roana’s biomass automation
The plant delivers manure from the barns into a pre-treatment tank that combines and equalises the material. This tank connects to an anaerobic digester system equipped with submersible mixers. Here, the bacterial strains digest biomass in an oxygen-free environment at temperatures like those in a buffalo’s stomach. The bacteria break down the complex organic substances, generating methane rich biogas.
The gas produced in the digester moves upwards, towards the dome, and is then directed to a gas treatment unit. Here the thermal process also helps to purify the gas and increase the concentration of methane. The end product goes to a gas-powered generator that produces enough electricity to push power back to the grid.
Control of the critical process parameters, such as temperature, gas pressure, in-feed rates and mixing within the digester plays a crucial role in maximising the volume and purity of the methane. The sensitivity of the system and its coordination makes the difference between it being profitable or not. Responsive biomass automation and network communications are vital to the plant’s commercial success.
Relying on high-quality automation solutions
To support Roana’s biogas operations, CC-Link IE Field gigabit Ethernet connects several devices to ensure high-performance communications. A MAPS SCADA system links to a MELSEC Q series PLC. This connects to five Mitsubishi energy-saving FR-F800 drives that regulate the functioning of all the electro-mechanical devices and components used in the process. As a result, operators have a comprehensive view of the entire plant and its processes in real-time for adjusting critical process parameters as well as conducting predictive maintenance strategies.
Mitsubishi Electric commented: “Our main goal was to deliver a system that is functional but also easy to use, maintain and expand. For example, as the plant develops and increases its volume of processed livestock manure, Roana could upgrade its system by installing a newer MELSEC iQ-R controller whose advanced onboard features support a broader range of I/O modules. The networking solution is already very flexible and advanced so future proofs the installation.”
Network speed and openness as gateway to future-proof operations
Key elements of CC-Link IE Field that helped deliver the vision are the network technology’s gigabit bandwidth and its openness. They allowed Roana to leverage a high-speed system with fast response times as well as a scalable infrastructure for upgrading to address future needs.
Now that the biomass automation power plant and its network infrastructure are operational, they can produce 2,400 kWh of electric energy every day. This supplies the national electrical grid, generating an extra revenue of £13,000 a month.
Finally, the farm likes this solution as it shows the benefits of renewable energy and maximising by-product use. The system is intuitive and easy to use and can manage itself without needing the farm staff to get new technical skills to control it.