Biochemicals: a future path for plastic packaging production

The risks of climate change now need little introduction. We are already starting to live with the impacts of a changing climate on the environment, communities, businesses and supply chains. The ambition to limit global warming to 1.5°C is now hanging by a thread, with voices challenging whether keeping within the 1.5°C trajectory is even still feasible - now making each 0.1°C rise above 1.5°C hugely significant.

With an increasingly narrow window to stabilise climate, it is now incumbent upon major primary industries to take a broader approach to sustainability than solely through decarbonising of energy sources. In addition to championing a truly circular economy particular, due to its immense responsibility to supply intermediate products to downstream manufacturers, the chemicals industry needs to curb its high dependency on fossil fuel completely. Specifically, this means finding alternative, renewable feedstocks to replace current petroleum-based ones in the production of chemical intermediates.

Often referred to as “renewable carbon”, the alternative feedstock sources available today are from biomass (typically wood, crops, manure, algae, etc.), from carbon capture or from the recycling of materials already used. For the purposes of this discussion, we are focusing on wood. Not only is it one of the most widely available feedstock sources – and, operationally speaking, one of the easiest to directly replace fossil-based sources - its chemical make-up allows for similar or even enhanced performance characteristics to their fossil-based counterparts.

At the root of the problem

In the 1950s the world produced only 2 million metric tons of plastic products annually. The amount has now risen to more than 400 million metric tons of which around 141 million is diverted to the manufacture of packaging.

Right across the plastics value chain – from resource extraction when methane and CO2 are vented into the atmosphere, through to the energy intensive processes to distil crude oil into chemical intermediates, the manufacturing process generates enormous amounts of greenhouse gas emissions.

According to the Organisation for Economic Co-operation and Development, plastics production was responsible for 1.8 billion metric tons of greenhouse gas emissions in 2019, equating to 3.4% of total global GHG emissions –  higher than the aviation sector which comes under significantly more scrutiny.

If the current pace of growth and manner of production continues, plastic packaging’s share of emissions is set to significantly increase. The World Economic Forum estimates that the plastic industry currently accounts for as much as 6% of global oil consumption and is expected to reach 20% by mid-century.

And the associated CO2 emissions could reach 1.34 gigatons per year by 2030 - the equivalent of three hundred 500-megawatt coal-fired power plants. And by 2050, plastic manufacturing could be responsible for up to 13% of our planet's total carbon budget - on a par with the emissions of 615-megawatt power stations.

But we need to look back through the plastic production value chain, to find the real root of the problem. Producing the many varieties of plastic requires a wide range of chemical additives – and  while each has its own special formula, they all come from a base of fossil fuels.

The chemicals system: beginning of the story

The chemical industry generates over $3.5 trillion in revenues annually, representing around 4% of global GDP – roughly equal to the output of Russia, the world’s fourth largest emitting country - and directly employing over 11 million people. But it also accounts for 4% of global greenhouse gas emissions, of which the International Energy Agency (IEA) estimates 75% is from the production of large-volume chemical intermediates (e.g. ethylene, propylene, benzene, toluene, ammonia, and methanol). And this does not include the emissions from the vast array of allied industries which rely on chemical intermediates essential to almost all sectors of the economy. These chemicals are present in agriculture, textiles, automotive, construction and many other systems, with 96% of manufactured goods depending on their use.

Specifically, the chemical industry is responsible for the vast number of fossil-based materials to manufacture plastic goods which form a significant part of our modern consumer world – including feedstocks for polyethylene terephthalate (PET), a form of plastic that can be moulded into bottles and packaging for countless food and personal care products. And many would argue that the industry has been slow in its ambition to develop innovative, less CO2-intensive feedstocks for plastic packaging materials.

Replacing fossil-based feedstocks – such as oil and natural gas - with renewable sources will lead to significant reductions in greenhouse gas (GHG) emissions. According to the American Chemical Society (ACS), even under the most conservative assumptions (i.e. 25% conversion and high separation energy), biochemicals can reduce GHG emissions by up to 88% - and up to 94% under the most optimistic conditions (i.e. 75% conversion and easy separation).

However, the chemical industry has so far lagged behind other sectors in transitioning their operations to sustainable models of operation – and until it does, it is impossible for other sectors reliant on chemical products to be truly sustainable.

Today, the global chemical value chain is predominantly linear, with low reuse and recycling rates and significant waste generation. For a transition to a more environmentally-friendly mode of operating to become a reality, the chemical industry needs to take a broader approach to sustainability than solely abating climate impacts through decarbonising of energy sources. It needs to curb its high dependency on fossil fuel completely. Specifically, this means finding alternative carbon sources to petroleum-based feedstocks for its chemical intermediates. In order for the industry to seriously play its part in becoming more sustainable, it is estimated that at least 59% of its feedstock (and up to 93%) should come from sustainable sources by 2050 - up from less than 5% in 2020.

While most countries now have an unambiguous strategy towards transitioning to 100% renewable energy systems by 2050 or 2060 based on solar, wind, hydrogen and other renewable energies,  there are few corresponding policies or strategies which demand the same of material feedstocks. This means we are largely reliant on the demands by downstream industries – and their consumers – for more sustainable products. Plus the foresight and sustainability ambitions of innovative chemical producers.  

But with almost the entire carbon feedstock used in the chemical system currently from virgin fossil sources, the transition to alternative feedstocks represents an enormous challenge. However, one bio-chemical innovator that has risen to the challenge - Finnish company, UPM Biochemicals – will be the first to produce wood-based biochemicals on a large scale, with its €750million biorefinery at Leuna in the German federal state of Saxony-Anhalt. Renewable wood-based biochemicals are one of the most innovative, yet practical solutions to the fossil-based feedstock transition, offering brand owners and material producers exciting new opportunities for improving their environmental performance. 

And UPM has ensured its wood-based feedstocks have sustainability built into each and every part of its value chain. All the wood used is fully traceable and supported by a verified third-party chain of custody, either FSC®- or PEFC-certified, and sourced from regional forests. Up to 60%, by far largest part of the wood harvested in Germany, is currently used for energy generation. It is burned. However, its use in long-life and recyclable products would make the best of the renewable carbon provided by wood and have a bigger impact in mitigating climate change. Valuing wood, using it wisely in the post-fossil world means we need to reduce the amount of wood used for fuel and energetic use and increase its material use to foster a circular economy and work towards zero virgin fossil feedstock.

Look to the forest

Trees are composed of 20-30% of lignin, a complex polymer found in the wood cell walls and giving wood its stiffness and resistance to degradation. This valuable compound can serve as raw materials in the production of bio-based chemicals which can be used in the manufacture of man-made fibres, among many other products. Lignin also offers UV and temperature stability, and even enhances moisture resistance, so helping to prevent bacterial and fungal attack. It is these properties that make lignin an ideal bio-based substitute for various petroleum-based products used today. Lignin has already found its way into a rapidly growing number of industrial applications such as resins, adhesives, bio-plastics, and polyurethanes. And not only do trees provide an environmentally friendly alternative to fossil-based feedstocks, they also absorb large amounts of CO2 during their growing phase and currently represent the only scalable “negative emissions” strategy. And trees of all varieties contribute significantly to improving biodiversity and wildlife habitats.

Not only is lignin bio-based, but the chemical intermediates that can be produced from it have the same chemical properties and performance as fossil-based chemicals and require no operational changes or retrofitting of existing manufacturing facilities. And its direct substitution for fossil-based feedstocks has a vast array of applications – particularly for the plastic packaging industry.

And the benefit of wood-based feedstock reaches far beyond just reducing emissions from the chemical production process. In addition to reducing the carbon footprint of an end product during the manufacturing phase, the carbon sequestered from the atmosphere by the trees is retained throughout the whole manufacturing process – so within the wood feedstock, the subsequent biochemical intermediate and even into the end product where it remains locked-in for life.

For our new state-of-the-art biorefinery, which is due to become operational in 2024, UPM will primarily use beechwood feedstock, from which it will produce 220,000 tonnes of biochemical intermediates annually. Beech trees are native to Germany and, as a species considered central to the country's long-term strategy to become more resilient to climate change. Forests in Central Europe are being rebuilt to become more diverse and climate resilient and a mix of species, nature protection and biodiversity standards are central to these regeneration efforts. This also means that new economical end uses must emerge which we provide as part of a push towards de-fossilising chemical and material value streams.

Beech has long been in demand in the furniture sector, but because manufacturers only want the trunks, the branches and forest management by-products have typically been incinerated, resulting in both a waste of high quality, useable raw material and contributing further to CO2 emissions.

UPM’s beech wood, including branches and off-cuts, are sourced from certified (FSC/PEFC), locally managed local forests, so neither competes for land for food production, nor requires fertilisers – two of the biggest criticisms of some other bio-feedstocks such as sugarcane. UPM also oversees the responsible planting, growing, harvesting and collection of beech trees, plus the residues and so-called thinnings from sawmill operations – of which around 70% normally ends up being incinerated.

It’s from this fully sustainable source that UPM Biochemicals has developed a new generation of renewable bio-based “drop-in” glycols. Mono-ethylene glycols (MEG) which are used extensively in PET resins are vital ingredients in the production of countless types of packaging.

Integration into existing manufacture can be easily implemented because UPM’s bio-glycol, BioPura™, is a molecular like-for-like substitute, enabling a much more sustainably sourced, virgin PET to be manufactured. Ideally, this innovative bio-based PET will be mechanically recycled at the end of life, just as its fossil-based counterparts should be. If it cannot, there is an option for it to be chemically recycled using ‘glycolysis’, with the process requiring additional new bio-based MEG to create new recycled PET. Through integrating BioPura™ as the additional “ingredient” will create a holistic circular economy in the PET value chain.

Conclusion

Wood is one of humanity’s most ancient raw materials but it can also take us into the future.

UPM Biochemicals is at the vanguard of the transition to a circular bioeconomy – where sustainable, renewable production and consumption is the new normal. It is pioneering sustainable chemistry – innovating in chemical processes, scaling biorefining and unlocking the potential of biomass to transform industries.

Replacing fossil and mineral-based materials with wood-based biochemical ingredients will also lock-in carbon sequestered from the atmosphere for the life of the product. This enables us to radically reduce the carbon footprint of materials and provide better, more sustainable choices to consumers.