Spiral seemed tanks to be supplied for PFI facility

Under the contract, Shanks will build a residual waste treatment facility (‘Facility’) at South Kirkby, which will employ a number of processes to treat and recycle waste from the Wakefield District transforming it into valuable products and green energy. The Facility will process up to 145,600 tonnes per annum of municipal solid waste, helping to increase the local authority’s landfill diversion rate towards 90 Precent.

The Facility includes an anaerobic digestion (AD) plant provided by the RRIJV. The AD plant forms part of the South Kirkby development, which is in-turn part of a 25-year, £750 million PFI contract awarded to Shanks by Wakefield Council. When completed the AD plant is designed to handle 65,000 tonnes of input per year and according to the RRIJV produce enough biogas energy to power over 3,000 homes. The AD process will also produce soil conditioner for use in brownfield restoration or similar projects.
Lipp Systems UK is providing three 19m diameter,19m high digestion tanks each with a capacity of 4,300 tonnes, together with three smaller tanks. The digestion tanks are being supplied with portal frame roofs to keep the weather at bay and a stainless steel diaphragm roof underneath to provide the gas seal.

”With recent storage and bio-digester tank failures hitting the media, significant attention is now being paid to the integrity of tank systems in new Anaerobic Digestion plants, which are critical to both meeting environmental standards and achieving efficient operation.” comments Andrew Shedden, Director of Lipp Systems in the UK “We offer a unique Spiral Seamed Tank (SST) system that is formed on-site and can be used as a liquid buffer tank, a digestate tank (with agitation and temperature control) and as a gas accumulator tank – everything you need for an AD plant.

“The Lipp double-fold seam system has been used to create more than 50,000 tanks across the world without a single leak or failure, it is also extremely fast to erect and provides unbeatable control over temperature and digestate stability within the bio-digestion process. These tanks have been used to great effect in the majority of AD plants in Germany, where the construction method was first developed, providing the crucial link in ensuring the total life cost projections of a plant are met.”

Commented Nick Small, Business Sector Leader – Waste and Energy at Imtech: “It is vital that we have absolute confidence in the integrity of the tanking system and Lipp Systems’ experience and track record is excellent.”

The Wakefield site is located at South Kirkby and is designed to process up to 230,000 tonnes of waste collected by Wakefield Council annually. Materials from the mixed waste stream are being separated into recyclable metals, plastics, and aggregates, plus organic matter.

The Facility will produce a refuse derived fuel for processing at a multi-fuel plant at the Ferrybridge Power Station for energy recovery. The remaining organics will be treated and further separated using an autoclave, before sterilisation and then used as in-feed for the AD plant.

Wakefield Council is intending for the facility to increase its recycling rate to at least 52 percent. Councillor Maureen Cummings, Wakefield Council’s Cabinet Member for Environment and Communities, said: “It is fantastic that a local company is working on this major infrastructure project which will help boost our local economy bringing vital jobs for the district.”