Mechanical Biological Treatment Waste Processing Facility Control System
Global Renewables Lancashire
Global Renewables Lancashire (GRL) is a UK based processing, resource recovery specialist working with Lancashire County Council and Blackpool Council on
the £2bn, 25-year Lancashire Waste PFI Project. The project saw the construction and operation of two state of- the art Mechanical Biological Treatment (MBT) waste processing facilities in Farington, near Preston and Thornton, near Blackpool. Together both plants are designed to process up to 600,000 tonnes of municiple waste each year, up to 85% of Lancashire’s waste and divert up to 75% of this from being sent to land fill.
The project enabled Lancashire to become one of the leading areas in Europe for environmentally friendly waste management, with a Capula control system at its heart. The two facilities’ processes are split into three areas; garden and kitchen waste is delivered directly into a dedicated composting facility, pre-sorted recyclables (like plastics, glass bottles and cans) are delivered into the Materials Recovery Facility at the Farington facility. Residual waste (mixed black bin bags) is taken to the Residual Waste Receivables Building where hand sorters will pick out any elements that could be detrimental to the organic element of the process before it is loaded onto conveyor belts and sent through the UR-3R Process®.
The UR-3R Process®, which stands for Urban Resource – Reduction, Recovery and Recycling, is unique in that resources inherent in the waste stream become cleaner at every stage of the process. Shredding and mixing are minimised; and separation processes are maximised using both mechanical and natural biological technologies. Waste is treated gently to enhance recovery of resources such as glass and paper. Resources that have a higher recovery cost than the current net value are rendered inert for either safe landfill disposal or separate storage. The process recovers the inorganic recyclable materials from the residual waste stream before sending the remains, which are mainly organic, to the percolators. The percolators agitate the organic portion of the waste, before it is moved to the Organics Building where it is pasteurised, sterilised and turned into Organic Growth Medium (OGM), a compost-like material, which will be used as a soil conditioner for woodland development and land reclamation within Lancashire. The leftover water, which is rich in organic materials, is then drained off and sent to two large digesters to generate green/renewable electricity which is used to run the facility.
As with many projects, time is a critical factor. In this instance, Capula was tasked with the responsibility of designing, installing and commissioning a complex networked process control system for the new-build waste treatment facility under tight timescales. Capula’s track record in meeting such exacting requirements was a key element in why they were chosen. In addition, the facilities operators need to submit regular, detailed reports in order to meet the tight regulatory
requirements. Capula will provide reporting facilities to capture data directly from the process control system and provide accurate and concise information as necessary. A wide variety of reports were required, from silo levels and percolation temperature profiles, to plant yield and efficiency key performance indicators.
How we helped
With many years’ experience within the waste, energy and process industries, Capula designed a control system based on Siemens S7 PLCs and WinCC SCADA. Switched Ethernet and Profibus fieldbus networks were used extensively across the site to link the control system to numerous intelligent motor control centres, variable speed drives and instrumentation to allow control of the entire facilities from sorting waste to energy production. The WinCC SCADA system provides a graphical overview of the entire process, accurately showing, in realtime, the status of process devices in all plant areas. All plant data is logged and stored for retrieval and analysis, therefore assisting in plant optimisation. The majority of plant devices and field instrumentation, including PLCs, VSDs and remote I/O are connected via a number of Profibus DP and PA networks, minimising field cabling and increasing the amount of data available for each individual device. Approximately 400 Siemens Simocode devices, located within the MCCs, were configured by Capula. A significant amount of cabling was reduced through the use of these devices and, in addition, the quality of diagnostic information returned to site technicians is considerably improved. The Profibus PA network connecting all intelligent instrumentation also enables the retrieval of detailed device information, further increasing plant status knowledge. As network manager, Capula was fully responsible for all Package Plant communications over the plant network. Many plant items are delivered with their own PLC for local control, and it was Capula’s responsibility to network each PLC and manage the network data. Furthermore, the education centre at the Leyland site is to feature a live view-only Capula SCADA terminal, showing what’s happening in the plant in real-time.
Capula’s knowledge of the waste management industry, together with their responsiveness through the tendering stage of the project proved Capula’s ability to both understand the project requirements and respond to project demands efficiently and effectively. Capula’s delivery track record was critical. Capula has a long standing relationship with Siemens as a Solution Partner, and regularly specify and use their equipment, as part of the mission critical solutions offered across various markets.