AN £8m anaerobic digestion plant will be officially launched this week, turning thousands of tonnes of food waste into energy and fertiliser. Deputy Business Editor Steven Hugill looks at its potential and why the plant is receiving support from a celebrity campaigner

NEVER shy in airing her opinion, Janet Street-Porter's eyes narrowed.

Peering over her shoulder, BBC Masterchef presenters John Torode and Gregg Wallace could tell it wasn't just the pans that were starting to boil over.

Her scowl, made larger with every stir of her wooden spoon, was a clear reflection of her disdain at their sour response.

The self-confessed queen of recycling and leftovers couldn't comprehend it.

The sheer waste of throwing her efforts into a bin for failing to meet only the highest presentation standards was simply perplexing.

Her mentors' knowing smiles at her reaction didn't sweeten the mood.

However, the North-East has a ready and unique salvation to her culinary chagrin and battle against wasting food.

Ms Street-Porter, who has a home in North Yorkshire, is a supporter of the Emerald Biogas plant, in Newton Aycliffe, County Durham, which will be officially launched on Friday (January 24).

The broadcaster, journalist and author, who backs a campaign to feed pigs with food waste, will be a guest at the £8m plant, to find out about its origins and potential.

Emerald says the plant, which began operations in October last year, is the region's first commercial food waste factory, and is capable of powering about 2,000 homes.

Using a process known as anaerobic digestion, the site is converting up to 50,000 tonnes of commercial food waste into heat, power and bio-fertiliser.

Separating packaging, such as glass and plastic, from waste, it turns it into electricity to be pumped into the National Grid.

It is also processing waste from local authorities, food companies and retailers from Northumberland to York and Cumbria, including Vale of Mowbray, SK Chilled Foods, which has bases in Middlesbrough and Wynyard, near Stockton, and Greencore, which has a plant in Consett, County Durham.

Bosses already have planning permission to expand the plant's capacity to four times its current size to increase work.

Its bio-fertiliser, which includes nutrients such as nitrogen, phosphate and potash, is being supplied to landowners and agricultural businesses within ten miles of the site.

The company is a partnership between food and recycling firm John Warren ABP, in Hamsterley, near Bishop Auckland, County Durham, and farming and land management company Agricore, run by Ian Bainbridge.

More than 100 guests, including Ms Street-Porter, will attend the factory's launch.

Antony Warren, Emerald Biogas director, says the plant will address a big issue in the region.

He said: “Food waste is a major concern for the North-East because 800,000 tonnes are generated every year.

“With the official launch of our plant, we are taking a leading role in developing a regional solution to this national problem.

“The opening of the food waste factory will build on the success and experience of the Emerald Biogas team.

“Through this investment, we will contribute a continued source of renewable energy to local businesses, while also providing a sustainable solution for dealing with food waste, which traditionally goes to landfill.

“We have employed the latest technology to make anaerobic digestion a feasible and cost effective alternative for commercial organisations in the North-East and to boost the campaign to reduce the amount of food waste created locally.”

In May last year, The Northern Echo's business team visited the plant while it was under construction.

Forced to battle severe weather and spend many days huddled in portable site office for shelter, Mr Warren said overcoming such challenges had given the company added momentum to succeed.

He said: “Security is one of the most important things for customers, and quite often when waste processes are started, they are fraught with difficulties.

“There are problems with letting down customers and also struggling to get materials, which leads to a bottleneck.

“However, we have all of those issues covered.

“Ian will take the digestate and the National Grid is not going to let us down either.

“We have contingencies in place to avert any problems with waste coming into the plant - that will be solved without anyone knowing, and that reflects the strength of our partnership.

“It is this knowledge and network of infrastructure, which provides added reassurance to our customers, that we are able to manage their waste effectively and will not have to rely upon landfill at any time.

“Once the anaerobic digestion process is complete, we can be completely confident that the by-products of energy and fertiliser will be used effectively.

“We know the power will eventually be supplied to local business, but Agricore also has access to a land bank that can accept the 50,000 tonnes of digestate produced annually.

“This approach sets us apart from our competitors and will ensure we are the leading anaerobic digestion facility in the North-East.”

Ms Street-Porter would indeed approve.

Just make sure her adversaries Torode and Wallace are kept well away.

WHAT THE UK THROWS AWAY:

  • The UK gets rid of about seven million tonnes of food and drink every year.
  • Seven million tonnes of food and drink would fill Wembley Stadium nine times over
  • That figure is equivalent to 260 kg for every household per year, or five kg for every household per week.
  • The average family wastes about £60 every month, throwing away almost an entire meal a day
  • The most thrown away foods are bread, potatoes, milk and meat

WHAT IS ANAEROBIC DIGESTION? 

  • Operating between 35 degrees C and 40 degrees C, the process takes place in a sealed and insulated vessel with controlled heating and mixing.
  • Commercial food waste is gathered from manufacturers, restaurants, cafes, shops and local authorities, and moved to a sealed building to be de-packaged, blended and pasteurised, and pumped into buffer tanks.
  • The waste is later pumped into a digester, where bacteria feed on the food waste and produce biogas.
  • Anaerobic digestion is made up of four bacterial processes:

Hydrolysis - Large molecules of carbohydrates, fats and protein are broken down to small water-soluble particles.

These are simple sugars, lipids and amino acids, and are now ready for the bacteria within the digester.

Acidogenesis - The products of hydrolysis are converted into volatile fatty acids (VFA) by bacteria, and are short-chained organic acid molecules, with the most important being acetic acid.

Acetogenesis - The VFAs are converted to acetic acid by bacteria.

Methanogenesis - Where the methane is made. Acetic acid is used by methane-forming bacteria, and the majority of the methane in biogas is produced in this manner.

  • During this continuous process, which lasts approximately six weeks, no methane is released into the atmosphere.
  • The biogas produced is typically made up of 60 per cent methane and 40 per cent carbon dioxide and is captured and used as a fuel in a combined heat and power unit.
  • The resultant liquid digestate, having had the majority of the organic material digested, is odour-free and stored in large covered tanks before being delivered to agricultural businesses within a ten to 15-mile radius of the site.
  • The use of this high-nutrient biofertiliser replaces the use of fossil fuel-derived fertiliser and ensures nothing is wasted from the entire food waste process.