Its a gas, gas, gas

Posted on 12 Nov 2010 by The Manufacturer

Last June, a MORI poll revealed that 68% of respondents favoured spending public money on British projects designed to tackle climate change. The government has said it will generate 20% of all our energy needs from renewable sources. Lorenzo Spoerry looks at the manufacturers doing their bit for the environment through the use of biogas.

Anaerobic digestion has been attracting a great deal of attention. Last year, the government made development of the technology a central plank of its waste reduction strategy, although few large-scale plants have been built as of yet. One of the problems is the size of the anaerobic digestion plant: a moderate-sized plant can take up around half an acre of space. Another is cultural; many manufacturers are reluctant to take on waste from larger producers.

The production methods are simple, safe and well-understood. Methane extracted through the biological breakdown of organic matter can be concentrated to the same standards as fossil natural gas. Produced through a process called anaerobic digestion, it uses biodegradable materials such as manure, sewage, municipal waste, green waste, plant materials and crops. Compressed, methane can be used in vehicle transportation. This form of fuel is already widely used in Germany, Sweden and Switzerland for both vehicle transportation as well as in manufacturing sites.

Coca-Cola Enterprises (CCE) are trialling, among some smaller vehicles, a 21-ton Iveco truck powered by biomethane extracted from a landfill site in Surrey.

The site collects gas from decomposing organic waste before it is upgraded to biomethane. The biomethane arrives at the Coca-Cola depot as a liquid, which is stored on site and put into the vehicle as a compressed gas. Darren O’Donnell, CCE’s logistics asset manager explained why the company is looking at alternative vehicle technologies to reduce its carbon footprint.

“If we want to meet our targets [CCE aims to reduce its CO2 emissions by 15% by 2020 against a 2007 baseline] it’s clear we should be looking at alternative vehicle and fuel technology,” says O’Donnell. “Biomethane is an attractive technology because of the significant cost savings available.”

The methane game
GENeco, a company that provides a recycling service for the production of renewable energy, is hoping that methane from sewage sludge could provide an environmentally friendly alternative for manufacturers to power their company vehicles. Its Bio-Bug car runs on methane made from anaerobic digestion, and collected from waste flushed down the toilets of the city of Avonmouth. The company is hoping that its Bio-Bug could appeal to CEOs looking for a way for their company to leave a smaller carbon footprint.

In addition, the GENeco site in Avonmouth has already been producing biogas for a number of years for export to local businesses and the national grid.

It uses state-of-the-art treatment facilities to accept a wide variety of commercial and food waste. A company spokesperson says, “Already successful in other parts of the world like Germany and Denmark, an increasing number of companies are favouring anaerobic digestion to recycle their waste as it reduces greenhouse gases and carbon emissions.

Our principal site in Avonmouth, near Bristol, has easy access to the M5 and M4, allowing companies in the south west and much further afield to benefit from using our treatment services.” The company works with SMEs and multinational companies across the UK. GENeco has very deliberately targeted SMEs and larger businesses as customers, trying to provide a highly efficient, cost effective service. It is trying to reduce the costs associated with transportation by opening small, regional works.

Adnams is a manufacturer with a tradition of environmental friendliness. Based in Southwold, the company has, in partnership with the Carbon Trust and the University of East Anglia, sought to reduce the carbon footprint of its East Green beer brand by 25%. Their new distribution centre, incorporating solar heating, has allowed the brewer to reduce its electricity bills by almost £50,000 per annum.

Now, it’s finished building a new anaerobic digestion plant, the first in the UK to use the waste product of the brewing process and local food waste to produce renewable gas. The company hopes to use the 4.8m kilowatt-hour per year the plant is expected to produce to power the Adnams brewery and run its fleet of lorries, while leaving almost 60% to sell back to the National Grid.

Emission commission
The Adnams Bio Energy plant contains three ‘digesters’: sealed vessels in which bacteria break down 12,500 tonnes of organic waste every year, producing biomethane for use in the brewery or in vehicles, as well as liquid organic fertiliser. The plant was built partly using funds from the European Regional Development Fund, the East of England Development Agency and the Department of Energy and Climate Change.

Andy Wood, chief executive of Adnams, says that for a number of years, the company had been investing in ways to reduce its impact on the environment. “The industrial ecological cycle is completed when the fertiliser produced from the anaerobic digestion system can be used on farmland to grow barley for our beer. This will have a major impact on reducing carbon emissions in the region and the production of renewable energy. The food waste would otherwise be destined for landfill, but processing it through the digester will save about 50,000 tonnes of CO2 equivalent from landfill.” Premier Foods announced earlier this year it was spending £5m to build a closed-loop commercial scale anaerobic digestion plant at its FR Brookes ready meals factory in Wales. The plant is expected to generate 300 kilowatts of energy when it becomes operational early next year, supplying around 6% of the factory’s energy consumption.

Although technically feasible, biogas energy may have to make a stronger economic case for itself if it is to be more widely adopted. However, as consumers and the government become increasingly concerned with instituting policies to meet the UK’s targets for emission reduction, biogas could emerge as one of many possible routes to a greener future.