Ensuring reliable heat and power generation
Read why with Ashdale’s expertise , Mitsubishi Electric’s automation technology delivers a highly accurate control solution for an anaerobic digestion plant in County Armagh
[Source: Mitsubishi Electric Europe B.V]
Mitsubishi Electric Automation Partner, Ashdale Engineering, located in Northern Ireland, has designed a highly accurate control system for an anaerobic digestion (AD) plant. The precision process control is achieved using Mitsubishi Electric automation components and is vital to ensuring continued operation of the live AD process, enabling the generation of heat and electricity that the plant operator now plans to sell to the grid.
The anaerobic digester at a large farm near Armagh drives a combined heating and power (CHP) plant that heats the farm’s buildings while also producing electricity. Animal slurry, silage and additives are mixed together and the resulting biomass then is heated to produce biogas, used to power the CHP. Based in Belfast, Ashdale Engineering became involved with the project because of its specialist expertise, having worked on AD projects for over 10 years in Northern Ireland together with Mitsubishi Electric.
One of the crucial aspects of anaerobic digestion is temperature control, as the microorganisms that break down the biomass require temperature stability. Fluctuations above one degree centigrade per day can kill them, stopping the process and with it, the generation of heat and power. In the event that this occurs, it takes considerable time to remove and replenish the biomass to restart the AD process. In addition to offering stability, the control system also needs to be responsive, easy to use and reliable.
Accurate control with Mitsubishi Electric PLC.
“The AD plant has capacity for around 40,000 m³ of biomass fuel and small changes to any of the variables can impact the temperature of the biomass,” says Adrian Whitten, Systems Manager at Ashdale Engineering.
By utilising the advanced programming features of the Mitsubishi Electric MELSEC-Q Series PLC, Ashdale Engineering was able to develop an accurate and reliable control solution.
An effective partnership for automation control systems
“We have a close and successful partnership with Ashdale Engineering and have been delivering solutions for a wide range of applications for over 35 years,” says Ciaran Moody, “This project is one example of many where we have worked together to exceed the customer’s expectations with the final result.”
Ciaran Moody, General Manager, Mitsubishi Electric Ireland.
High reliability Mitsubishi Electric drives
“Choosing the correct variable speed drive for the application and the careful consideration of the fieldbus network that links all plant components is critical,” says Simon Murray, Variable Speed Drives Product Manager, Mitsubishi Electric. “With the assured reliability of the FR-800 series drive range from Mitsubishi Electric, combined with Ashdale’s extensive skills and experience, delivery of this AD plant control system was seamless, from design to final commissioning.”
The next stage for the AD plant operator is to expand the process and export biomethane as well as electricity to the grid. This requires an increase in the methane content of the produced biogas from 70% to 90%, the level needed for export to the grid, which will be achieved by the partnership between Ashdale Engineering and Mitsubishi Electric
.“This project is a good example of what can be achieved in the development of an AD plant and biomass upgrade. Together with Mitsubishi Electric’s automation technologies and technical support, we have designed, installed and can support the whole system,” concludes Adrian.