On earth, all our power derives from the sun, our local star, a massive ball of nuclear reactions giving off the heat and light which drives our world. We all know this – but remembering it is crucial to appreciating the importance of Mass Balance.
Our planetary machine is made up of a finite amount of matter – mountains, oceans, fresh waters, soil and minerals, air, trees and other plants, all the animals, and you, me and everyone else.
It all works very nicely, but what does cosmology have to do with the timber industry?
Barring the occasional meteorite coming in and the odd space satellite going out, the earth has a constant amount of matter, regardless of human and natural activity. In the scientific world, it’s called the law of conversion of matter: physical or chemical changes do not destroy or create matter, they merely change the form of it.
So with the timber industry: whatever process wood is subjected to, the mass involved remains the same. When a wood product is created, it will go through one or more processes after felling. A single log of say, 6m³, may end up as only 2m³ of finished product yet the other 4m³ of mass has not disappeared, it has merely been converted into the equivalent of 4m³ of co-products, residue or waste. The total matter derived from the end of the process is the same as the amount at the start. This is where Mass Balance comes in: mass flows of material input equal mass flows of material output. By tracing the flows of mass along the timber supply chain, we can see how much of the original timber mass ends up as waste.
Leaking waste
If the supply chain is a pipe through which material has to flow, we can imagine leaks of mass at each point where processes are carried out. These leaks include not just wood, but the energy, other materials, transport fuels and any water involved in the process.
No longer are we hand-wringing over pollution and end of life waste. Mass balance flows help us to gain a better understanding of how energy, materials and the environment are inextricably linked by the consequences of modern industrial processes. The concept of Mass Balance emphasises that waste is being created throughout the supply chain, not just when the final product is thrown on the skip.
Perceptions are that waste has no value – yet its disposal does have a cost. Who carries that burden of cost is changing rapidly, and not in industry’s favour.
So perceptions about what is and isn’t waste need to change. If post-manufacturing matter genuinely is not a residue (residue has a potential use), and cannot be reused, recycled or recovered, either because it is not physically possible or, more likely, not commercially viable, then it is waste in the legally defined EU-sense. Yet the legal definition makes no mention of ‘unwanted’, as the dictionary does. This ‘unwanted’ attitude to the by-products of manufacturing needs to change in the timber industry as much as any other sector. If, instead of waste, we think of what’s left over as potential revenue, then we’ve taken the first step to avoid potentially costly waste.
Landfill costs
The bulk of UK waste goes into expensive, potentially hazardous and environmentally unsound landfill. Burying waste costs and, increasingly, the cost is being shifted from local and central government to industry. Legislation is now the environmental stick and the obvious trend is towards more and more exacting taxes from both Westminster and Brussels. Given the recent Bonn environmental agreement, there can be only one direction for environment taxes to go: up.
It’s becoming your cost so what should be done about it? First, we have to forget Victorian ideas about manufacturing as a linear process, from the forest to the sawmill to the processor to the merchants to the end user. Use of any matter on earth should be regarded as part of a cyclical process – which acknowledges sustainability. Many in the construction industry are already working with that concept, from design through to end of intended use.
There are several drivers for this change, not least Sir John Egan’s Rethinking Construction report, which threw down the gauntlet of sustainability and was an acknowledgement of wider societal change, away from the disposable culture. Although sustainability is a challenge, it is a business opportunity too.
To compete in a sustainable manner, the new business mantra must be that of the four Rs: reduce, reuse, recycle and recover. Of these, the most important is reduce; if waste is minimised, it saves you having to do the other three in the first place.
You might argue that as a matter of economic necessity your business already keeps woodwaste down to a minimum, as it’s your raw material and the more of it you can use, the bigger the profits. But are you really monitoring all the potential leaks and, if you are, what action is being taken to minimise the leaks? And what about the leaks you can’t stop entirely – is that just regarded as waste?
Wood is easier to recycle than materials used by many sectors. Residues can be converted to commercially saleable products relatively easily –materials for panel manufacture, sawdust, animal bedding, horticultural/ agricultural mulches and as bio fuel for combined heat and power units.
Energy source
If nothing else, wood can always be burnt to provide energy. The carbon released is absorbed by at least an equivalent amount of trees that are planted as Europe’s forests continue to grow. This is the ideal: to have wood as forests that act as carbon sinks, tying-up excessive greenhouse gases, not as wood waste in landfill, locked-up in forms too toxic or economically impractical to reuse, recycle or recover.
Yet planting trees alone won’t solve our over-reliance on the non-renewable resources such as fossil fuels and wasteful use of other natural resources, which drive modern industrial processes. Fossil-fuel use leads to more global warming (latest UN figures suggest temperature rises twice the magnitude of those previously thought), with more flooding – which will permanently reduce the amount of landmass. This means there’s less room to grow trees to soak up carbon dioxide, the main greenhouse-effect culprit, creating a vicious circle. If you think any of this is science fiction or scaremongering, just remember the floods the UK suffered over the past 12 months. Ingenuity is required to stop and reverse this state of affairs – and the timber industry has the means to make its own contribution and to create new markets.
Imaginative use and reuse of materials opens up secondary markets. Materials destined for the skip can be sorted by type. The extra time needed to fill material-specific skips is compensated for by the value of the timber and other reusable/recoverable materials that, mixed together, would have just been so much landfill rubbish. Innovative products and, more importantly, innovative designs can reduce the hazardous chemicals with which we imbue timber. This then makes it more economically viable to recover and reuse at the end of its intended life.
One of the biggest Mass Balance flows of all occurs when a product comes to the end of its intended use. Designers are beginning to appreciate that the cyclical demands of the Four Rs include thinking ahead to disposal. In construction, demolition can be replaced with deconstruction.
Practical approach
All these concepts, which effectively plug or lessen the flow of the Mass Balance leaks, come together in some exciting construction projects where timber is a principal material.
The Peabody Trust‘s Bedzed Project in south London is a mixture of work units and apartments, constructed, as much as possible, with reclaimed materials. Where possible, local sources of materials have been preferred, reducing fuel use.
Other innovative uses of timber range from roundwood thinnings for timber buildings at Hooke Park to choosing engineered wood products rather than traditional construction materials in public-use buildings such as primary schools.
The consequences of not following these attitudes to timber and other materials are immense: if we don’t acknowledge the waste flows that Mass Balance will highlight in the timber industry, we won’t be able to measure the size of the problem.
TRADA Technology is working on a Biffaward project to raise awareness in the UK timber industries of the need for wood waste minimisation. At the centre of this work is a website (www.recycle-it.org.uk), which acts as a resource on all aspects of sustainable timber use. It has free advice, how-to-guides, legislation information and self-assessment tools to help you embrace waste minimisation.
Clearly, attitudes must change. The timber industries now need to accept the Mass Balance concept in order to identify the size of the challenge ahead of them, and to realise the benefits that waste management in a finite, sun-driven world can bring.
Related Files
Diagram 2: the cyclical process in construction
Diagram 1: the planetary machine
