Landfill bans on food waste have been introduced in certain European countries as well as across the Atlantic, with mixed results. But does closing the door on landfilled food waste open the door and guarantee feedstock to anaerobic digestion? David Burrows reports.
The time is right. The time to invest in this technology is now.” That was Brian Dick, Quest Recycling Services chief executive talking at the Biocycle Tenth Annual Renewable Energy from Organics Recycling Conference in Des Moines, Iowa. The technology he refers to is, of course, anaerobic digestion (AD).
Dick called on the audience to embrace the waste to energy (WtE) revolution to build additional outlets to process organics into energy and compost. With the U.S. generating over 27 million tonnes of food waste every year, there is certainly plenty of supply.
However, of the 200 operating anaerobic digesters, only a select few have the capacity to process food waste. Indeed, the U.S. can often be caught casting jealous glances across the Atlantic, where the technology has been a success for two decades.
A study by Organic Waste Systems (OWS) in Belgium found that the number of plants treating the organic fraction of household waste in Europe has grown from three in 1990 up to 62 in 2000. This figure is set to pass 170 by the end of this year. This will offer the continent a digestion capacity of more than five million tonnes per year, handling almost 3% of the organic fraction of municipal solid waste produced in Europe by 2010. Although this figure could seem small, it represents 20% - 30% of the biological treatment capacity for organics derived from household waste.AD and energy security
However, biogas as a source of energy goes further back than 1990. Much further. The first attempts at burning marsh gas were made as early as the 18th Century. More recently, biogas was of particular interest to Germany at the end of World War II, when the country was cut off from energy imports.
Natural oil then, of course, began to dominate – until recently. Across the globe, governments, companies and consumers are being pushed to reduce their reliance on oil (and coal) as the world looks to mitigate the impacts of climate change through reductions in carbon emissions. National energy policies are being revamped partly to take this into account, but perhaps more so to mitigate risks from dwindling supplies. Energy security has become a prominent theme.
In August 2008, the conflict in the Caucasus set alarm bells ringing given Georgia’s pivotal role in supplying Central Asian oil to the West. A few months later, Russian prime minister Vladimir Putin told gas giant Gazprom to cut supplies sent via Ukraine to Europe over allegations that Kiev was siphoning some off.
In the UK, a further warning came that year when a “big freeze” sent demand for gas soaring to record highs as consumers attempted to keep their homes warm. The country’s national grid was forced into a “gas balancing act” with big generators switching from gas to oil-fired power.
Though energy companies are often quick to provide assurances that supplies will not run out, and that more reserves will be found, emerging policies look to other solutions that include the generation of renewable energy. In the mix, to varying extents, is AD. As the OWS report concluded: AD’s key advantage is its capacity to recover renewable energy from organic waste.
Indeed, AD has been first out of the gates as countries look to divert waste from landfill, mitigate climate change and develop alternative energy sources. Companies are thus making substantial efforts to find markets for the technology and submit new applications for biogas. This has seen new countries implement the technology and countries with digestion experience increase their capacity – much as Brian Dick is hoping for in the U.S.Landfill bans on food waste
Many countries are looking to the AD pacesetters like Germany and Sweden for inspiration; as a result, the idea of landfill bans on food waste has taken centre stage. The most successful countries in terms of recycling are those that have introduced landfill bans.
Support for food waste bans is therefore emerging in other countries where it is felt a ban would provide greater certainty to AD developers and funders. Indeed, the European Commission is also said to be keen on the idea of landfill bans per se; although their implementation is outside its remit there is a feeling that the commission is eager to see more bans in place. Austria, Germany, Sweden and the Netherlands all have bans on sending some biodegradable wastes or recyclable materials to landfill.
This has all sparked interest among policymakers: the theory is that if food waste is banned from landfill, there is more chance of meeting the targets under Europe’s Landfill Directive, while also securing more renewable energy as the waste is diverted to anaerobic treatment plants.
“A ban on biodegradable waste would be expected to improve investor confidence in the provision of alternatives to landfill, and this effect might be expected to be stronger in the case of the commercial and industrial waste sector, where security of supply of waste into treatment facilities remains a major barrier to securing financial support,” a global study by the UK-based Waste & Resources Action Programme (Wrap) concludes.
But it isn’t quite as simple as that, as the Wrap report adds: “The issue of security of supply might not be completely resolved by such a ban as long as covenants provided by commercial waste producers remain weak from the perspective of investors.”
In other words, a landfill ban is not a silver bullet. “On its own [a landfill ban] is too crude,” says Dominic Hogg, director at waste management consultancy, Eunomia.
“Landfill bans are blunt instruments and care has to be taken to ensure that they don’t simply lead to a switch from landfilling to incineration.”
Dr Hogg says he prefers to see some form of driver to separate biowaste at source. “A well implemented ‘requirement to sort’ organics, accompanied by ‘end of waste standards’ or something similar, is likely to do more to foster AD than a ban,” he adds.Introduction of new regulations
Austria, Germany and Holland all require the sorting of organic waste by households. In Sweden, an initial ban on “combustible waste” was altered to cover “organic waste” – slightly peculiar, given that the former includes the latter.
However, targets were set for the treatment of source-segregated biowaste to “head off the switch of organics from landfill to incineration”. Denmark, meanwhile, provides an example of where the ban approach may not deliver much in the way of food-sourced AD: in Denmark there is little source separation of food and most food waste is incinerated, according to Dr Hogg.
“In practice, if treatment of separately collected biowaste is being sought, what’s needed is some means to drive source separation,” adds Dr Hogg.
“If, as in countries such as Germany and Austria, rules for the development of source separation are put in place, then the effect of the ban seems to be simply to change the way residual waste is managed. If they aren’t [like Denmark, and initially Sweden], you don’t get separate collection and the main effect is the development of residual waste capacity. Much also depends, obviously, upon the relative costs of the alternative treatment routes.”
Indeed it does. Landfill bans have been implemented by many countries in Europe and municipalities in North America and Canada; all have the overall aim of moving waste treatment and management up the hierarchy (to focus on prevention, reuse and recycling). To that end, the bans are usually implemented within a framework of existing policy measures, such as landfill taxes.
The cost implication to any producer of waste will be the difference between treatment costs and landfill costs, and the latter is largely a function of landfill tax rates: higher landfill taxes encourage diversion, and thus alternative treatments, more attractive.
For Neil Riding, technical director at Wardell Armstrong, an international independent engineering and environmental consultancy, landfill bans may well not achieve anything that a landfill tax can do on its own.
“This might be rather simplistic but the treatment of commercial and industrial waste in particular has been, and will continue to be, driven commercially – if it’s cheaper to treat than dispose to landfill then that’s what the market will do,” he says. “We’ve obtained planning consent for large scale (100,000 tonnes a year) AD facility developments in the UK that are not reliant on any landfill ban of food waste – they are predicated financially on rising landfill tax and gate fee levels.”Picking the right policies
The British Government has already declared that it won’t introduce wholesale landfill bans anytime soon. Instead it’s declared its intention to divert waste from landfill using the escalation of landfill tax which will eventually make diversion and recycling a better financial option for the producers. Riding says using landfill tax as a financial driver also ensures the development of treatment capacity keeps pace with demand. Indeed, landfill bans cannot be introduced overnight – the infrastructure needs to be in place to take the waste for alternative treatment.
There is some debate as to whether an outright ban on sending certain waste streams to landfill is any more effective in the long term than the use of landfill tax
As Gunnel Klingberg, secretary general at Municipal Waste Europe, explains: “Implementing a landfill ban takes a very long time. In Germany, there was a decade between introduction and enforcement.”
Those countries that have implemented a ban with a short lead in time have benefited from high landfill taxes to further encourage the use of alternative treatment technologies. When Flanders, Belgium, implemented its landfill ban, legislation allowed landfill operators to apply for exemptions where there was not the required alternative treatment infrastructure in place. This has had the effect of slowing down the development of new infrastructure needed to meet the requirements of the ban.
Where countries can struggle, is if they use neighbours to provide some of their waste disposal capacity, as Tolvik Consulting director, Adrian Judge, explains: “If landfill bans are enforced before sufficient infrastructure is constructed then it could run the risk of distorting the market. For example, heightened gate fees charged at existing waste treatment facilities could lead to an increase in the export of waste to those countries that can dispose of it in a more economic way.”
This happened between Germany and the Netherlands – although it’s worth noting that the Netherlands sought to curb the trend by allowing for dispensations to landfill waste locally if a lack of available treatment capacity could be demonstrated.
If a comprehensive treatment network is not in place then countries also run the risk of biowaste being sent for incineration rather than composting or AD due to a lack of capacity, the costs involved with bulking and transportation, or local policy (as Eunomia’s Dr Hogg alluded to).The role of market forces
Of course, in order to develop the infrastructure required, treatment facilities need to be confident that feedstock will be available and at a price that works economically. Indeed, market forces are another complication in the landfill ban mix – and another reason why any ban needs to be part of a wider waste, environmental and energy policy, says Municipal Waste Europe’s Klingberg.
“The policy for anaerobic digestion almost needs to be created independently of any ban,” she says. “You need to think about the social, technical, environmental and economic reasons for any decisions. That means that for AD you can’t just think about what goes in – you must also think about what comes out and whether you are producing something the market wants. And can afford. The last thing you want is to use public funds to finance an operation, only for the project to fail for market reasons.”
When it comes to AD, there are two main outputs: digestate and energy. These can both offer drivers for AD in their own right. In the view of Mike Van Acoleyen, a senior project leader at international consultancy, Arcadis, supporting the generation of renewable energy and the use – or the market development of – composted digestate would make AD “competitive”, particularly if combined with taxes or other measures to make landfilling or incineration more expensive.A ‘balanced’ portfolio of measures
Van Acoleyen – much like Klingberg, and many other experts – believes landfill bans must be part of a “balanced” portfolio of policy measures. A landfill ban simply prohibits certain waste materials from being landfilled – so, in isolation, it does not guarantee food waste, if that is the material banned, will end up in AD.
“It’s unlikely that legislative changes could ever be introduced that would direct treatment options to a particular technology,” says Derek Greedy, chair of the International Solid Waste Association’s Working Group on Landfill. “AD will have to stand up financially in its own right if it is to thrive and flourish.”
The countries that have made bans work have installed a policy mix of measures; the ban is just one. In line with that they have developed composting or AD alternatives; supported the use and the market for compost; prevented the generation of biowaste at source; limited cross-border movements; used (para)fiscal drivers and supported home-composting.
This requires joined up policies through government too, including departments interested in soil quality, waste collection, energy, heat and resource self-sufficiency. “There is no point introducing one policy measure and it has an adverse impact from that expected,” adds Sarahjane Widdowson, principal consultant at AEA Technology. “Fiscal, legislative and social measures are all important in helping shift behaviour and ensuring that organic waste is treated correctly and utilised more as a resource and not a waste.”
David Burrows is an environmental journalist who specialises in the topic of waste managementMore Waste Management World Articles
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