On-site Digestion of Cheese Manufacturing Residues
I am finding that more companies in the Dairy processing sector (and other food and beverage manufacturers) are realising that their production residues are a source of renewable energy rather than just an escalating cost. The public also seem to love the idea, following the number of positive comments we’ve received after the press announcement on our latest “cheese gas to grid” plant that will power the equivalent of 4000 homes in Cumbria.
Corporate expectations are now changing regarding the deployment of AD technology, with interest more widely across the food processing sector. Now industry leaders are backing the approach that we have been promoting for the last 5 years. Following the recent Paris Climate Change Summit, CEO’s of leading global companies including Unilever and Nestle stated: “We want the facilities where we make our products to be powered by renewable energy with nothing going to waste.”
If dairy processing companies want to assess the value of energy in their processing residues, they need look no further than what’s happening at First Milk’s creamery in the Lake District. Here, anaerobic digestion is converting processing residues from cheese making into energy for use in the creamery. Based on significant cost savings, compared to traditional treatment, this offers an attractive investment return, in many cases this can be less than 5 years.
On-Site Digestion – Green Energy From Cheese
First Milk’s cheese creamery in the scenic Lake District, is the largest on-site digestion plant in the European dairy processing sector and the first in Europe to feed gas into the grid, based only on treating residues from cheese making, without other non-dairy feedstocks. We are currently busy commissioning the plant at Aspatria and it’s already producing over 1,500m3 per day of process residues for the digester. When fully on stream, the bio-energy plant will reduce the site’s annual fossil fuel energy consumption by at least 25%!
The on-site AD plant treats both trade effluent and whey permeate. When fully operational, we expect it to generate up to 1000m3/ day of biogas, 80% of which will be upgraded for injection to the national gas grid, from where some of the gas will power the site’s boilers. The balance will be used in combined heat and power (CHP) engine to supply power to the site.
Lake District Biogas was set up to manage the project with external funding, to allow First Milk to concentrate on core milk processing activity. We were asked to design, build and operate the bio-energy plant because of our track record in on-site digestion.
Clearfleau’s technology will also remove 7,000 tonnes of carbon per annum from the supply chain. Cleansed water is discharged to the river Ellen (after removal of phosphates and greatly reducing bio-oxygen demand). Importantly, the plant provides economic benefits to the creamery and its farmer owners, also helping to safeguard 100 local jobs in rural Cumbria, while eliminating frequent truck journeys and fuel costs.
Despite extensive development of AD plants on farms across Europe, there has been limited deployment on food factories, even though adding value to process residues has the ability to reduce a site’s carbon footprint. This is a sector of the AD market, where the UK is taking the lead on technology and deployment. We are looking at a number of dairy projects in the UK, but are also interested in projects in Ireland and elsewhere in the European dairy sector.
With dairy sector prices under pressure and farmers leaving the industry, dairy companies can now benefit from the cost savings and efficiencies offered by the digestion of their processing residues. Hopefully stakeholders across the dairy sector will become more aware of how on-site AD can save costs and reduce carbon emissions from producing some of our staple foods.
Proven benefits from the deployment of on-site digestion in the food processing sector include reduced energy costs, lower effluent treatment costs and cutting off-site disposal costs. For bi-products like whey or fatty process residues the revenue from AD can outweigh the return from other markets. Food processors can generate value from digesting their residues with a better return on the investment required than for other conventional treatment and disposal options.
If you are interested in discussing how you can benefit from this technology, contact us below.