I have dedicated the best part of my working life to developing and promoting bio-based plastic. I’ve watched closely as the sugarcane industry in my native Brazil has developed.
I’ve visited sugar mills across the Centre South region and spoken with lifecycle experts and customers.
The more I learn about this crop, the more I believe it will be a vital tool for the plastics in the years to come.
But the same question always remains: can the use of sugarcane to produce plastics ever replace the use of petroleum derivatives?
As a child, I learned at school that sugarcane arrived in Brazil during the colonial period and that the “sugar-based economic cycle” went from the 16th to the 18th century.
However, it was only during the 1970s, amid the first oil crisis, that the Brazilian government developed a program called Pro-álcool (proalcohol) aimed at reducing Brazil’s dependence on oil imports.
As a result, the automotive industry in Brazil launched the world’s first large-scale production of cars fueled solely by bioethanol and sugarcane production in Brazil grew exponentially.
Unfortunately, during the 1990s, the program lost momentum and only green-minded people (like my dad) were still sticking with their ethanol-fueled cars.
It was in the early 2000s that an ethanol revolution started in Brazil. With the development of Flex-fuel technology and a second growth cycle ahead, this agro-industry started to re-invest and modernize itself.
Innovation has driven sugarcane to new heights. Mechanized harvesting, fertigation1, co-generation of electricity from the abundant crushed cane fibers (bagasse) and, most importantly, a relentless focus on social and environmental responsibility have resulted in one of the most sustainable sectors in the country, recognized worldwide.
It is important to highlight that Brazil is the biggest sugar exporter in the world and sugarcane generates 17% of all energy consumed in Brazil.
All that using approximately 1% of the country’s area (2,9% of the arable land) and preserving by law, 20% of the original vegetation of this vast farmland.
The use of ethanol as a biofuel is for sure great as it significantly reduces CO2 and NOx emissions when replacing fossil fuels.
Nevertheless, it makes more sense to give the carbon captured by photosynthesis a more noble use: rather than burning it for energy, materials like biopolymers have a longer and potentially circular lifecycle.
This keeps the carbon out of the atmosphere as long as possible, thus contributing to slowing down climate change.
So here comes my vision, clearly inspired by the principles of the Circular Economy: responsibly cultivated sugarcane will be used to produce bioplastics from ethanol, which when designed into recyclable products, will stay in the value chain for several years, being mechanically recycled many times.
If by any reason mechanical recycling is not possible, the product will find its way to a chemical recycling process, which will bring this biobased carbon molecule back to virgin quality plastic.
Inevitable side streams of this process will end up being used to produce heat or electricity in a thermoelectric power plant and this is ok, because this carbon is not fossil! The envisioned value chain is described in the illustration below.
As illustrated in figure 2, sugarcane can continue to supply the transport sector while increasing its participation as feedstock for the biopolymers industry.
Given that Brazil is committed to reaching a yearly production of 54 billion liters by 2030 (as one of its contributions to the Paris Agreement), if only 10% is diverted to bioplastics, this would allow for the replacement of 2,2MMt of fossil plastics.
If this happens under the depicted model, it is quite clear to me that the overall environmental and social benefit will be even higher than simply using the ethanol as a biofuel.
To conclude, my answer to the initial question is a bold yes. Sugarcane is already replacing a significant amount of petroleum derivatives in plastic production and it will continue doing so, as we continue moving towards a new plastics economy, which is more circular and significantly lower in carbon emissions.
(1) Fertigation is a water and nutrient recycling process, which consists of applying vinasse a residue from the distillery to the plantation.
This article was written by Martin Clemesha, Circular Economy materials – Marketing & Product Management | Biopolymers Global Strategy at Braskem
Sources
- https://sugarcane.org
- http://plasticoverde.braskem.com.br/site.aspx/plastic-green
- https://www.mma.gov.br/images/arquivos/clima/convencao/indc/Bases_elaboracao_iNDC.pdf