The conference that never was
The annual Waste Conference, which is held in Coffs Harbour each May, is renowned as being one of the most popular held in Australia each year and usually attracts 600-700 attendees.
So when our Chief Operating Officer Trevor Bayley was selected as a speaker this year, we were all very pleased at the opportunity of addressing such an important audience.
But like so many such gatherings Waste 2020 has been cancelled. The organisers instead asked speakers to publish their papers on the Conference’s website, which we have done.
We have also reproduced it for you in this blog post.
Waste 2020 Conference Speech by GDT COO Trevor Bayley
The theme of this conference is that the key to economic resource recovery is to add value.
This theme crosses a number of concepts, including the circular economy, recycling vs re-purposing, sustainability, the closed loop and so on. These are all modern catch phrases and expressions that conjure different images depending on the topic under discussion.
Let us start with some simple deﬁnitions:
- Resource: A source of supply that can be readily drawn upon when needed.
- Resource Recovery: Using waste as an input material to create valuable products as new outputs.
When discussing the virtues and challenges of the recovery of resources from the waste stream in which I am interested, End of Life Tyres, I could stop right there. The Destructive Distillation process developed by GDTC does exactly that. It delivers three valuable products, completely new in the sense that there is no material comparison possible between the input and output, which are in high demand in the global trading arena.
Perhaps I should explain further.
A GDT tyre recycling plant comprises six processing modules and will handle 19,300 tonnes of tyres a year while the volume of high value recycled material that is produced by the process is impressive. A typical 10 kg car tyre yields 4 litres of oil, 4kg of carbon, 2kg of steel, a 70kg truck tyre provides 27 litres of oil, 28 kg of carbon, 15 kg of steel and a 4 tonne oversize mining dump truck tyre 1.6 tonnes of carbon, 0.8 tonne of steel and 1500 litres of oil.
But, let’s go back to the basics: What are we talking about? This is an old tyre – a product with which we are all familiar.
To be more speciﬁc, it is an ELT, or an end-of-life tyre as it has passed the point where it can be retreaded and reused and if it were reﬁtted to a vehicle, it would be a danger to life and have a high potential to blowout.
There are one and a half billion ELTs generated around the world, each year. With Australia as the focus for this discussion, we are talking about approximately 26 million tyres, 55 million EPU’s or more dramatically 550,000 tonnes of rubber tyres that are not biodegradable and will not disappear on their own for an estimated 500 years.
That volume repeats itself each year and is growing with the population increase and the number of vehicles on the road.
We are a road-using nation, and whether it is an electric car, a high performance sports car, or a B-Double truck, the one thing they have in common is the way the power is transmitted to the road and tyres have proven to be irreplaceable in that context.
End of Life tyres have been an environmental problem since they were developed by Scotsman John Boyd Dunlop in 1888, because we have made them so well that they don’t rot and go away, but could remain for 500 years or more. How long, no one really knows?
But it was the increasing popularity of the motor car in the early 1900s and the development of synthetic rubber in the 1920’s that created the massive environmental problem we have today.
Today’s tyres are a mixture of raw and synthetic rubber with the black colour coming from the carbon black which is a vital ingredient and provides the strength, durability and heat resistance.
By comparison, the original tyres made from natural rubber that were used in 1900 were prone to punctures and wall failure and would only do 8,000 kms or less, without replacement.
What do you see in this picture? It’s not just about the toxic black smoke going into the atmosphere, or the clean up after the fire. It’s about the waste of energy.
It is estimated that only 22% of the energy required to get a new tyre on the road is used during its useful life. At GDT, we recover approximately 80% of that retained energy in the form of oil and carbon. The energy held in the steel skeleton is retained and delivered to the steel recycler for recovery there.
When discussion turns to ‘waste to energy’, the ‘energy’ generally referred to is ‘electrical energy’. This can and does cause confusion.
The GDT process recovers the energy stored in an end of life tyre but that energy comes in two distinct forms, neither of which is electricity. One is a liquid, oil, with an energy content of 46 Gj/t. The other is a solid in powder form, carbon, with an energy content of 33 Gj/t. When a policy requires recovered energy be put back into the grid it ignores the fact that energy comes in multiple forms.
If we were recovering sugar from a cake, how would we direct the energy in the sugar into the grid? Perhaps have a bicycle connected to a generator?
Recycling or repurposing?
If you take a glass bottle and process it such that you can make another glass bottle out of it, is that recycling? If you take the same glass bottle and grind it into sand and use it in the building industry isn’t that repurposing?
If we use the same analogy with tyres then it is all but impossible to recycle them. A tyre cannot be deconstructed in any way that will enable it to be reconstructed.
But if you take the tyre and process it such a way that you convert the rubber into crumbs that can be used in cushioning for sporting surfaces, combined with binders and moulded into rubber ﬂoor tiles, mixed with asphalt and laid on roads, is that not re-purposing?
Vulcanised rubber is just vulcanised rubber. It cannot be transformed by mechanical means. It is estimated that vulcanised rubber will not bio-degrade within a 500-year time frame. Tyre manufacturers have invested billions of dollars to ensure that a vulcanised rubber tyre will not wear out other than by friction and abrasion. Their safety depends on it.
So what will happen to the sporting surface that relies on crumb rubber from tyres to simulate the cushioning of a natural surface once it wears out? If it needs replacing within the estimated 500 year time frame then there will be a lot of rubber crumb that will require some kind of disposal.
This problem has begun to manifest itself in the United States where a large number of synthetic turf sports ﬁelds have become worn out. These are now being stockpiled awaiting a solution for disposal.
Alternatively, tyres are been cut into chips or shreds and classiﬁed as Tyre Derived Fuel (TDF). A great marketing term. ‘Derived’ implies it comes from the tyre, when in fact, it is the tyre just cut into pieces, and fuel means it is burnt as a substitute for coal.
Rubber has a high caloriﬁc value and gives much more value for money than coal, but when burnt it produces more toxins in the exhaust and leaves a hazardous ash that needs disposal. It also had a price advantage but that is gradually disappearing as coal becomes less favoured over other heat sources and it’s price is in decline.
Then there is pyrolysis. This process is used in numerous waste applications for treatment of green waste, sewage, wood etc. In the case of tyres it is widely used in the developing world, in particular India and the sub-Continent, Malaysia, Thailand and Cambodia.
Pyrolysis for tyres is regarded as extremely hazardous and environmentally destructive. In most cases, it requires the tyres be pre-processed, either crumbed or chipped.
As a result of this pre-processing there are only two products delivered, the steel is extracted prior to pyrolysing, a liquid product condensed from the vapour, and a solid powdered residue (plus a quantity of gas which is used to deliver some of the heat required). The liquid is of inferior quality and is no longer referred to as oil, but ‘rubber derived liquid’. The solid residue is referred to as ‘recovered carbon black’ (rCB) which requires some level of post processing to enable market acceptance.
Finally there is GDT’s “Destructive Distillation” process. Based in pyrolysis there are a number of similarities but there are more differences and that is where the signiﬁcance lies.
The most obvious difference is in the feedstock. GDT processes whole tyres, there is no preprocessing required. That leaves us with the products of the process. The vapour produced from the breakdown of the tyre is collected via vacuum and condensed into a black oil.
Once all the vapour has been extracted the residual carbon, in combination with the steel skeleton is extracted and separated. The oil product is a high quality, stable oil with a large percentage falling within the ‘diesel range’ rendering it suitable for further reﬁning into fuel substitutes ranging from diesel through to parafﬁn and kerosene (jet fuel).
The steel is delivered clean and unchanged from that which was used to manufacture the tyre. It is a high tensile steel, which enjoys high demand in the scrap steel industry. The carbon is over 90% pure and has proven to be easily upgraded into rCB for use back in the tyre and rubber industry but can also be processed readily into battery ready graphite. We believe that the GDT process is true recycling.
Circular economy vs linear economy
We hear a lot of political discourse around the term ‘circular economy’. One presumes the opposite to circular is ‘linear’ so I would like to take a quick look at the nuances of recycling and repurposing under the light of circular and linear economics.
Steel and metal recycling are probably the earliest examples of where a product enters a completely circular economy that goes on ad infinitum. The only reason we have to keep mining is the growth of population and the need for more and more infrastructure to satisfy the demand. Is value added? It certainly would be if it would cause a reduction in mining activity.
In the case of tyres the story is quite different. Disregarding the use of tyres as artiﬁcial reefs, construction and engineering (riverbanks, road building etc.), works of ‘art’ etc., which are clearly only disposal, we are left with the three methods of treatment currently available plus GDT.
Crumbs: The rubber from the tread of the tyre is ground to deliver crumbs of various sizes. These crumbs are used as fill for sporting surfaces and horse arenas. They are combined with asphalt to make road surface. They are combined with binders to make rubber mats. In the end, they are still crumbs of rubber. My suggestion is that falls under the category of the linear economy. What do you think?
If we address the theme of adding value then I suggest that there is a cost component in making the conversion, which adds to the price of the product, but I cannot see a value add in its use as it does not realistically replace anything. It is merely being used because something needs to be done with the ELT.
Chips: The whole tyre is shredded into chips and used as tyre derived fuels (TDF). This is used as a replacement for other kinds of heat energy derived from fossil fuels and has proven beneﬁcial in some industries by helping them reduce dependence on coal – bricks, cement, ceramics etc. It would seem to be a straight linear economic activity, which stops once the tyre has been burnt. Incidentally they are only chipped to assist in lowering transportation costs, and perhaps to enable less changes to the furnace feed system.
Pyrolysis: Another use for crumb rubber. Already adding value has been impacted due to the cost of feedstock. Given the poor quality of the liquid produced from the process, and the high percentage of gas re-used by the process, then any value, any circular economy implications can only come from the carbon, or char as it is sometimes called.
Circular and linear economies aside it has proven difﬁcult to make a straight business economy work outside of the developing countries where it is prevalent. There are a number of European and US enterprises trying to add improvements to the process, as it is clearly better than crumbing or chipping.
How does it rate in the circular vs linear equation? Assuming the carbon (char) finds a market as a replacement for carbons derived from mining or manufacture from fossil fuels, and then they achieve a percentage of circular success.
Destructive Distillation (GDT): Tyres are treated whole and since there is a tipping fee attached to the disposal of tyres, that goes some way towards covering the cost of process. Of the oil produced from the process, about 3% is used to provide the heat that makes it happen and 100% of the tyre is returned in one of three products; steel, oil and carbon.
All three products are traded on global commodity markets. The carbon product has the potential to be upgraded via a post process application that will replace mined or manufactured commodities in the same market place, as opposed to being used as a straight heat source.
The end-of-life tyre management industry is moving away from crumbing and chipping partly due to the cost and partly due to the limited market for the products.
Many countries around the world are following a legislative path to try and encourage new technologies and to bring a solution to their own problems. Countries in South America are leading the way via mining tyre disposal.
The biggest mining economies have enacted laws that actually require the ELT be removed from the country, not just from the mine. They have no restrictions on the form the tyre is in, whether it is whole, crumbed, or even as oil or carbon. Just that 100% of the tyre that is imported new must be exported.
At GDT we have seen this coming and have proven our process works with whole mining tyres as well and to manage this we have established a joint venture with another Australian company, a specialist in the transportation of mining tyres from wharf to mine site and back.
Countries outside of South America are looking at introducing similar legislation and in a situation like Australia, where all tyres are imported; it becomes an attractive proposition for the Government to put the disposal of the end-of-life tyre firmly in the hands of the importer/distributor. The shrinking markets for crumb and tyre derived fuel play well into the GDT space.
Data on the fate of end-of-life tyres in Australia and almost every other country in the world, is confusing and most likely inaccurate. That is the result of years of industry neglect, a history of uncontrolled management, underworld involvement and apathy on the part of the tyre companies.
This is rapidly changing, though I am here to tell you that anecdotal evidence would suggest we have a very long way to go before we can rely on the published numbers.
As things stand, we can state that a single GDT plant in Australia is capable of processing a minimum of 19,300 tonnes of mixed tyres, up to Super Single size, and that is equivalent to 4% of the stated annual ELT volume.
With the current estimate of 48% being baled and exported to India likely to be reduced by Federal Government bans coming into effect in December 2021, GDT is ideally poised to start taking up that slack. By doing so, the value currently being attributed to the ELT will come back to Australia and will create new markets and perhaps even new industries.
Oil – As I mentioned the oil produced from the GDT process is stable and capable of reﬁning and/or blending. It ﬁts into a standard classiﬁcation for oil products and is therefore subject of an index in terms of global price. This makes the value uniform around the world.
Carbon – It is affectionately known as the ‘sleeping giant’ in our business.
Carbon is the most widely used industrial chemical in the world.
On its own, this product has the most potential to add value to the waste stream that is the end-of-life tyres, as processed by GDT. In its raw state it can be used as a substitute for, or additive to, coke in the provision of heat to any number of industries.
Further processing can spread its potential into recovered carbon black (rCB) for use back in the rubber industry, in inks and toners, paints and even explosives.
We have experienced fantastic results with a newly patented process from NZ that has converted it into “battery ready” graphite, a product that is going through a phase of rapidly increasing demand while the natural sources are diminishing or are controlled by China.
Steel – This is a high tensile steel wire that is unchanged through the process.
The steel is in high demand by the steel recycling industry.
Again, this is a benchmarked product in demand at the same value around the world.
Global production of tyres exceeds 1.7bn per year. It is increasing as more of the third world becomes increasingly affluent and adopts the motor car and truck as the preferred form of transport.
Investment in new tyre facilities is increasing, along with investment in facilities to supply the ingredients. This includes carbon black, which is traditionally made from petroleum products.
Tyres are high-tech and not only do they transmit engine power to the road, they provide a high level of safety in operation. Their ‘value’ depreciates rapidly during their useful life and in a worst case scenario in one year they can go from A$100 per unit for a tyre from a low cost country, to A$7, which is the cost of disposal at many urban tyre retailers 1 year.
GDT receives a portion of that A$7, currently A$2, to recycle the tyre and aims to increase the gross value by approximately A$3. On the way, it provides employment and permanently removes the problem of vulcanised rubber from the waste landscape.
We are well advanced in taking the GDT technology to the USA, South Africa and the UK. Although we are only a minor player at this stage we believe we will have a much bigger impact on the environment and to the replacement of fossil fuels.