Waste not, want not

Technological innovation has transformed what’s possible when it comes to material reuse, recycling, and recovery. But to truly work towards a zero waste future – particularly in the demolition sector – mindset and collaboration are arguably just as important as engineering advancements, believes our managing director, Marcus Brew.

As countries vocally pledge to make greater progress when it comes to climate change, there can be no escaping conversation about zero waste strategies and the steps that need to be taken – by all – to get us there.

The media is dominated with headlines about carbon reduction, sustainability strategies, upcycling and more, and this is important – the environment has become everyone’s ‘problem’. But with this increased interest – not to mention pressure – comes opportunity too. Opportunity that, to date, only those closest to the waste industry itself have perhaps truly acknowledged.

Waste machinery innovations

From an engineering perspective, technological advancements are continuing at pace among waste machinery manufacturers. It’s now possible to shred a king size mattress in as little as 25 seconds, for example, to liberate the materials that would otherwise remain ‘locked’ inside and achieve a 100% material recovery rate. That means the salvaging of metal for smelting and remanufacturing; foam breakdown for use as carpet underlay or animal bedding; wood for landscaping mulch or a biomass resource; and textile fibres which can be reused in oil filters or used as flock in energy recovery, to reduce the world’s over-reliance on ever-depleting fossil fuels.

This wouldn’t have been possible a couple of years ago.

Now, demolition contractors may not find themselves needing to dispose of many unwanted mattresses. But the point to note here is that machinery innovations are changing the face of what’s possible when it comes to transforming even the bulkiest and trickiest of so-called wastes into something new. Landfill – or worse still, unlawful dumping – is not the only option for these troublesome materials. And in actual fact, the handling of these tricky materials could soon become a revenue generating exercise.

Demolition professionals may therefore be keen to note that the same technology, mentioned above, is helping specialist hazardous waste contractors shred contaminated materials such as IBCs, rags and oil filters, for re-use, recycling and the production of alternative fuels. It can process uPVC window frames for FE, non-FE and clean uPVC recovery. It can aid the recycling of a variety of gypsum board products. It can liberate high value metals from large redundant electronic appliances right through to mixed skip waste.

That’s why anything that was previously deemed unshreddable – at least from an economical perspective – should now be re-evaluated for its resource potential.

Waste hierarchy compliance

The global economic challenges caused by the pandemic have, in some respects, also given the environmental sector this new impetus. In other words, it isn’t just machinery innovation alone. Material prices have rocketed – compounded by supply chain difficulties – which means there is more of a fiscal driver to think differently about reuse and recycling. Secondary materials can often be resold for use instead of virgin equivalents, which represents the potential to generate a new – and often growing – revenue stream.

This is why an increasing number of demolition firms are closely aligned with waste specialists – some even have waste handling divisions themselves. And why not? If you look to the cement industry, many of the large manufacturers have even established co-processing facilities, whereby they collect local municipal solid waste (MSW), commercial and industrial (C&I) waste, and construction and demolition (C&D) waste, for recycling, with any residual material being transformed into an alternative fuel which can be used as an energy source when manufacturing cement in their kilns.

And here lies an important point. Where practical, we should strive for material utilisation in line with the waste hierarchy. While this is a framework conceptualised and adopted by EU nations, it does to some extent set the precedent in other developed countries too. It recommends that, naturally, the prevention of waste at source is key. However, where waste materials do arise, the next-step actions in priority order should be reuse, then recycling and, lastly energy recovery. Landfill should be considered the absolute final resort.

So, while recovery should not be front and centre of every environmental agenda, Waste to Energy does represent a relevant option for certain ‘wastes’. Contaminated materials that cannot be re-inserted into the manufacturing loop without extensive cleansing, such as PVC processing pipe for example, could make a great fuel source if they have a high calorific value. Yes, technology may exist to recycle them if rigorously cleaned, but if the process is overly energy intensive or excessively costly, the net environmental gain is minimised, if not potentially null and void. There must therefore be a common-sense attitude.

What has innovation achieved?

Key innovations within the waste machinery space centre on the development of shredding technology which, thanks to a higher torque drive, can operate at slower speeds without any detriment to material throughput rates. Traditionally, higher speed shredding would have been required which – aside from being dangerous – typically results in regular unexpected breakdowns and costly damage if the machine encounters material that is too difficult, if not impossible to shred. This leads to operational disruption, capacity limitations, excessive maintenance, and, overall, a perception that the handling of bulky or heavy-duty wastes, is uneconomical – when it needn’t be.

For example, it is often possible for 38 tonne waste shredders to pay for themselves in as little as 18 months.

And here comes the financial argument again, which contractors shouldn’t be ashamed of. Because, while a growing number of companies have a genuinely strong environmental conscience, being ‘green’ needs to make commercial sense too. When it does, more people will be financially incentivised to get involved.

Energy efficiencies boost economic benefits

The introduction of electric-driven shredders into the market has brought added benefits. Undoubtedly safer to operate than diesel hydraulic equivalents – not least because of the reduced fire risk – they require up to 75% less energy to run. While boosting the environmental integrity of the shredding process, such machines drastically lower operators’ fuel consumption costs too, which further strengthens the business case for the C&D waste handling process. And that’s before the imminent red diesel fuel duty is introduced, which will further erode the margins of firms running non-electric driven machines.

Contractors seeking new machines should also look for input material flexibility, as waste streams arising from demolition sites are typically varied. Such versatility means one machine is often equipped to handle very different waste challenges. Output flexibility and particle precision matters too. If the shredded material is to be subjected to further downstream processing, a homogenous liberated product is crucial, as uniformity aids the future reuse, recycling or recovery potential.

Look beyond technology

But even the most pioneering of machinery innovations can’t wholly solve the C&D waste challenges being experienced on a global basis.

Sadly, legislation is often required to drive true innovation, which goes some way to explaining the introduction of new Waste Wood Classification Guidance. While currently specific to the UK market only, it won’t be long before other countries follow suit when it comes to this particular waste stream.

A mindset shift would also undoubtedly help. The very term ‘waste’ is, in itself, unhelpful of course. It conjures up somewhat ‘dirty’ images of rubbish that – as the word implies – has reached the end of its useful life. Some contractors sadly still see waste as a headache – and a headache they’re keen to pass on. But the examples outlined – albeit briefly – throughout, highlight that even the most complex wastes are not actually a headache any longer.

They would be even less of a headache if stakeholders at earlier stages in the value chain thought about what will happen to buildings, structures, plant and equipment, when it reaches the end of its operational lifecycle. Because, just as product innovation in the domestic appliance and car manufacturing sector has evidenced, if reuse is factored into the design of something before it even exists, it is far easier to cleanly and efficiently break the item down into its component parts when it is no longer being utilised. The environmental and economic benefits can therefore be maximised as a result – and more people would get involved as the ‘headache’ has arguably disappeared completely. That’s true green construction, beyond simply the use of carbon efficient materials and building techniques.

A shining example

While the narrative here implies that the demolition and waste sectors could work harder to drive further environmental progress, it is crucial to note in conclusion, that these two industries set a shining example for others, in many respects. Many demolition sites boast 90-95% material recycling rates, particularly the high-profile projects likely to impose greater scrutiny during the contractor’s tender and selection process. And clever on-site segregation of materials usually lies at the heart of successful material handling and onward treatment.

But while steel and aggregates from heavy buildings can now be reused and recycled with ease, and ‘waste’ such as redundant cables is now a huge environmental success story, the resource value in 5-10% of site materials still remains untapped. And a great degree of potential actually exists here – far more than people think.

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