Thursday, 30 July 2015 11:11

Cumbrian dairy uses residues to send biogas to grid and clean its effluent

Bio-degradable residues from cheese production at a First Milk creamery in Cumbria are being used to power the factory, send green gas to the national grid - and also remove the phosphate discharged to river in the effluent.

clearfleur cheese1 copyLake District Biogas (LDB), a company set up to manage the project for First Milk, has commissioned Clearfleau to design, build and operate the bio-energy plant. When operational at the cheese creamery in Aspatria, rural Cumbria, Clearfleau's proven, British digestion technology will reduce residual sludge management costs, while generating renewable energy for use on site.

Clearfleau has finished the first stage at Aspatria, one of the UK's largest cheese creameries. Once operational, the plant will be the first dairy processing site in Europe to feed bio-methane into the gas grid.

Revenue benefits will include 20-year index-linked, government-backed incentive (FiT and RHI) payments. When commissioned, the digesters will generate 1000m3/ day of biogas, much of which will be upgraded for injection into the national grid. Some bio-methane will be used in the creamery for steam generation, reducing net purchase of fossil fuels, while the rest of the gas will be consumed by local users.

Tom Northway, Director of Lake District Biogas says: "Clearfleau's on-site digestion technology has been selected as it has a proven track record in the dairy sector. It will optimise gas output and deliver a solid return on capital invested. We are delighted this will be the first plant in the dairy sector to supply green gas to the national gas grid."

The feedstock from the Aspatria creamery site comprises low-strength wash waters such as process rinses, supplemented by whey permeate - the cheese production residues present after protein extraction for use in energy supplements. This will be pumped to the anaerobic digestion (AD) plant from the creamery.

clearfleur cheese2As an initial step, Clearfleau refurbished the existing aerobic plant to enable First Milk to significantly reduce levels of phosphate in their effluent, which is discharged to the River Ellen. This will ensure an early delivery of new tighter discharge standards, which are required by the Water Framework Directive.

Stewart Mounsey, Environment Manager at the Environment Agency welcomed the early delivery of this work and says: "This will make a significant contribution towards the reduction in phosphate levels in the river. It's important for the health of our rivers and streams that businesses do their bit to help reduce pollution and improve water quality".

The integrated on-site AD plant will take over from the existing aerobic plant in early 2016 and will treat the creamery's wastewater output as well as its whey permeate.

Clearfleau's on-site AD technology is proven to reduce the chemical oxygen demand (COD) of the production residues by 95%. Aerobic polishing will then remove residual COD and nutrients such as nitrates and phosphates to allow safe river discharge.

Craig Chapman, CEO of Clearfleau Limited said: "Use of aerobic treatment for dairy processing residues is outdated. The revenue and energy contribution from AD offers a much better return than a new aerobic plant. Moreover most AD systems are not suited to dairy feedstock or treating feedstock containing fatty residues.

"The project will generate biogas solely from cheese production residues, using advanced British technology. It is a very positive move by First Milk to future proof their leading creamery operation by generating a significant proportion of their site's future energy needs."

This project is a major development for First Milk and its partners, Lake District Biogas, Renewables Unlimited and Clearfleau Ltd.

Clearfleau Ltd
First Milk - Aspatria
Lake District Biogas
Renewables Unlimited