Leaders digest

By David Burrows

- Last updated on GMT

Related tags Food waste Anaerobic digestion Waste

Food waste is a valuable commodity and a lot of manufacturers understand that
Food waste is a valuable commodity and a lot of manufacturers understand that
Winning formulas for waste reap rewards, reports David Burrows

It's been a couple of years since the climate change minister Greg Barker referred to anaerobic digestion (AD) as a "no brainer"​. Since then there has been an AD strategy to push the technology in England, along with £10M of funding to divert 300,000t more food waste away from landfill. But there's still a feeling that plans and funding are not being turned into capacity and energy.

"The government is talking about growth and that [AD] could deliver 35,000 jobs and an industry worth over £3bn in the UK,"​ says Charlotte Morton, chief executive of the Anaerobic Digestion and Biogas Association (ADBA). "[So] I'm really surprised they aren't focusing more on this."

Well, north of the border, they are. In May, the Scottish Parliament passed the new Waste (Scotland) Regulations, which represent what some have hailed as the "biggest step change in 20 years bigger even than landfill tax and statutory recycling rates"​. The new 'zero waste' regulations have a number of requirements but one of the most challenging involves food waste. By 2014 businesses that produce more than 50kg of food waste a week will have to separate it for collection. Smaller firms will have until 2015 to comply. By the same date local authorities will all be offering food waste collection services (with few exceptions) and, by 2020, there is likely to be an outright ban on biodegradable materials, including food, going to landfill.

So, what does this mean for food manufacturers? Are they aware of the regulations? And how likely is it that England, Wales and Northern Ireland will follow suit?

"The new regulations will be a real game changer,"​ says Louise McGregor, head of market development at the government's waste adviser, Zero Waste Scotland (ZWS). "When they kick in it will mean much more food waste getting to AD and IVC [in-vessel compost], so sites that may currently be struggling to reach capacity will quickly notice a change."

It's no secret that some plants are struggling for feedstock food waste at the moment. Towards the end of last year, four plants were built in quick succession, followed in May by the largest yet, at Barkip, which has a capacity to process 75,000t of organic waste and produce 2.2MW of renewable electricity. ZWS estimates that there is enough capacity at the moment to process 70% of the food waste generated by Scotland's businesses and households but "there is plenty of food waste not being collected across all sectors"​. The new regulations will change that, bringing thousands of tonnes more food waste onto the market from households. However, it's the business waste plants crave.

"Food manufacturers are probably doing quite a lot already [to deal with their waste] with the landfill tax having pushed them that way,"​ says ZWS's McGregor. "Some could be commanding revenue from their waste for example, if it generates a lot of gas."

Indeed, some food manufacturers can find themselves in a position of power when it comes to negotiating waste contracts. Unlike the mixed bag of oft-contaminated waste that the average kitchen bin provides, business waste can be clean, consistent and ideal for the bacteria that break it down and convert it into gas. "Food waste is a valuable commodity and a lot of food manufacturers understand that,"​ admits one waste company.

Indeed they do. "I've been to the Barkip plant and they'd love our waste, but they can't afford it,"​ explains Alan Cameron, group environmental manager at Browns Food Group.

Cameron currently sends bones, salmon heads and the like for rendering, which brings in £20/t. If that was sent to landfill it would cost £80/t so "I'm up about £100/t"​, he says. AD is an option he has considered but, with the plants costing so much to build, the inevitable gate fees have put him off.

Options considered

Others are also not yet convinced that it's the best option for their businesses. Colin Campbell, operations director at Albert Bartlett, has also been approached by waste companies "desperate for our waste". However, they go away disappointed: 100% of the potato crop is used, be it for retail, processing or cattle feed. "Financially, AD doesn't work for us,"​ he says.

How the new waste regulations will affect gate fees at AD plants north of the border is unclear. Consultants don't expect the fees to plummet they are currently lower than those at landfill sites but what happens to the price will depend on how many local authorities opt for separate food waste collections. Cost is a barrier that will force some councils to go for combined food and garden waste collections, which will then go for composting rather than AD.

Whatever happens, landfill will remain the most costly option and any business that produces food waste will be looking very closely, if they haven't already done so, at outlets for their food waste. Some, of course, will invest in their own plants, as the likes of McCain Foods and Diageo have done.

McCain's covered anaerobic treatment lagoon the size of two football pitches produces methane for burning or flaring from 77,000m3​ of wastewater rich in potato starch. The anaerobic lagoon is covered to keep out oxygen and enables collection of methane for burning in the combined heat and power (CHP) gas engine. Enough electricity is produced to meet about 10% of the Whittlesey factory's needs.

Liquid waste isn't covered by the waste regulations, but it will be a focus for ZWS with the Scottish food and drink sector excluding whisky generating 1.59Mt of it every year. Much of it is discharged to effluent treatment which, according to McGregor, is a waste of a valuable resource.

"If it was recycled through AD, it could help provide heat, power and biofertiliser, while providing an opportunity for industry to reduce its waste disposal and energy costs,"​ she explains. McGregor hopes the "spirit of the regulations"​ will encourage more businesses to make better use of the resources that are not covered under the new laws but are still thrown away.

Campbell at Albert Bartlett's says it's a foolish business that hasn't looked at its waste policy in the last five years. While many in the food industry are already dealing with their food waste in more sustainable, cost-effective ways, much will change in the next five years.

Collection costs could come down, making AD a more economically viable option for smaller and medium-sized manufacturers. Meanwhile. further incentives and rising energy costs could see other companies follow in the footsteps of the likes of McCain and Diageo by investing in their own plants.

No one doubts that the clarity of the policy in Scotland has provided AD technology with a welcome boost. Adam Read, AEA practice director (waste management and resource efficiency), says it is the biggest step change the waste management industry has faced in the last 20 to 25 years.

"It's bigger than when landfill tax was introduced and bigger than statutory recycling rates. Those moves didn't have the same leap of faith as this one. There is no clearer policy."

It's also far-removed from the piecemeal approach south of the border. To date, there are 78 AD plants in the UK outside those used by the water industry delivering four times more electricity than solar photovoltaics.

ADBA chairman Lord Redesdale says interest in the sector is growing and "with the right support from government, we could see an eightfold increase in renewable energy from AD by 2020"​. By then, Scotland could already have a ban on sending food to landfill. Will it always be one step ahead?

Food Manufacture​ is planning to hold a round table event on anaerobic digestion in London in conjunction with international law firm Stephenson Harwood. To find out more about this event please email uryra.qneol@jeoz.pbz​.

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