The research, entitled ‘Environmental benefits of recycling – 2010 update', builds on a 2006 study commissioned by WRAP (see letsrecycle.com story) which looked at the impact of landfilling, recycling or incinerating materials.
In the 256-page document, WRAP scrutinised over 200 life cycle analyses of waste material disposal to consider which route would give the most preferred benefits on four fronts: climate change abatement; energy demand; water consumption; and, depletion of natural resources.
The research looked at food waste, garden waste, textiles and biopolymers and advancements in waste treatment technologies, such as pyrolysis, gasification and anaerobic digestion.
Aluminium, steel, glass and aggregates, which had been part of the 2006 study, were excluded because there has been little change in treatment technology for these materials, so it was considered that there would be little change in the results.
And, while recycling emerged as the preferred disposal option for paper, cardboard, plastics and biopolymers, the 2010 report gives credence to the idea that – in some cases – it may be beneficial for material to be used in energy recovery applications.
The attention given to thermal treatment methods in the report comes in the wake of WRAP announcing in October 2009 that it would be changing its agenda to include a focus on developing markets for energy-from-waste (see letsrecycle.com story).
The executive summary for the report states: “This report reinforces the key conclusion of the first report that recycling of paper/cardboard, plastics and biopolymers for most indicators assessed gives more environmental benefits than other waste management options.”
Paper
In its assessment of the preferred disposal option for paper, WRAP explained that the relationship between incineration and recycling “appears more complex” than in the 2006 study, which could be attributed to the development of new thermal treatment technologies.
And, while it claimed that recycling is preferable in terms of meeting energy demand and water consumption, they were found to be broadly comparable in terms of climate change potential.
Keith James, environmental policy manager at WRAP, claimed that the finding was similar to that made in the 2006 report, and said it was important to stress that the quality of paper being recycled diminishes each time it is recycled. And, once it is of too low quality to be recycled further, it is important to find appropriate outlets.
The research highlights three case studies, including French and Swedish examples, where incineration appeared on a comparable level with recycling.
The report states: “The comparison between recycling and incineration appears more complex, as better energy recovery efficiencies have been built into the more recent LCAs. In general, the data shows that recycling is preferable for energy demand and water consumption, but they are comparable for climate change.”
Biopolymers
Speaking to letsrecycle.com, Mr James said: “With bio-polymers there is not that much on the market at the moment so there isn't enough to warrant separate collection.”
On the subject of plastics as a whole, the WRAP report claims that incineration with energy recovery “performs poorly” and the preferred treatment method is stated as mechanical recycling – a finding which WRAP said conforms with the outcomes of the 2006 study.
The new report claimed that mechanical recycling of plastics is the best waste management option and that the benefits were mainly achieved due to avoiding production of virgin plastics.
Food and garden waste
On the topic of food and garden waste, anaerobic digestion emerged as the preferred treatment option, with composting and energy recovery deemed comparable in their contribution to climate change potential.
In addition, the report claimed that home compost bins should be properly managed and aerated, to avoid anaerobic conditions forming, which could result in the emission of methane.
Wood and Textiles
The lack of published life cycle analyses was raised as a point of contention in the report when it attempted to consider the best possible option for wood and textile materials.
Despite the lack of available data for the two material streams, WRAP claimed that incineration with energy recovery would be the preferable option for wood in terms of energy demand, while recycling was preferred for climate change potential.
Meanwhile, it was assessed – from the data available – that recycling had “substantial environmental benefits” for textiles, with the scale of the benefits dependent on recovery routes and the avoidance of material production.
This lack of available data also hampered WRAP's intention of assessing the impact of new waste treatment technologies – which, WRAP claimed, had a “disappointing” number of life cycle analyses available. However, the study claimed the data that was available was “very encouraging”.
Commenting on the overall aim of the study, Mr James said: “We were interested in understanding how technology is developing because, obviously, things don't stand still and we need to understand how much has changed in those intervening four years and what the options now are for a range of materials We wanted to see what evidence is out there.”
The report is set to be formally published on WRAP's website later today (March 16).
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