The different types of sustainable plastics

Bioplastics, bio-based, biodegradable, recyclable and recycled plastics. The spectrum of sustainable plastics is broad and the different types of plastics and their sustainability advantages can be very confusing. In this blog, Brazilian bio-based plastics producer Braskem with European headquarters in Rotterdam, explains the differences.

The origin story: bio-based versus regular plastic

Let's start by explaining a little bit more about regular plastic. The vast majority of these plastics are derived from the oil and gas industry. Bio-based plastic, however, is produced from plants. This means the source of carbon that is in the plastic is bio-based and renewable, giving it a major sustainability advantage.

What falls under bioplastic: bio-based versus biodegradable plastic

People often associate bioplastics with biodegradable plastics. But bioplastic is an overarching term that allows for several definitions. It refers to all plastics that are either bio-based, biodegradable or both.

So what's the difference between bio-based and biodegradable? Well, whereas bio-based plastic says something about the origin of the product, the term biodegradable says something about its end of life. Although bio-based plastics are made from plants, it doesn't necessarily mean that they are biodegradable. Depending on several factors such as the composition and thickness of the final article, biodegradation can take from days up to months and even years. While all types are expected to biodegrade in industrial composting facilities, only a few will biodegrade in water (i.e rivers, lakes and ocean). Most are bio-based but a few are made from petrochemicals too.

The three types of bioplastic

As a result, we can categorize bioplastics in three types. The first type of bioplastics are bio-based and biodegradable. The second type of bioplastics are bio-based, but not biodegradable. Also known as drop-in bioplastics, they have the same composition of regular plastics and can therefore be recycled using the existing infrastructure already in place. If a plastic article is recycled, this means that it comes from a product that has already fulfilled its purpose and is successfully circled back into the production of a new product. The last type of bioplastics are petrochemical plastics that are biodegradable. Although biodegrading petrochemicals emits fossil CO², the purpose of this type of bioplastic is normally to improve the performance of some biobased and biodegradable plastics, that can be too brittle without being modified, for example.

How degradable is biodegradable plastic?

Some bio-based plastics are also biodegradable. While that sounds like a good way to avoid plastic pollution, it does not mean that people can litter and that all biodegradable plastic degrades in nature over a short period of time. In practice, the biodegradation process mainly offers advantages for applications where recycling isn't possible or economically viable.



Recycling bio-based plastic

What about bio-based plastics that are recyclable? Bio-based plastics from Braskem are 'drop-in', which means that their molecular composition is exactly the same as regular plastic. As a result, they can go along with the regular recycling stream and be used again in the circular value chain as new products. How does that work? Braskem's bio-based plastic is made from sugarcane, which is crushed in order to produce sugar and bio-ethanol. The bio-ethanol is dehydrated and broken down into ethylene and water. This ethylene forms the basis of bio-based plastic, just like with regular plastic!

The main sustainability advantage of this type of plastic is that by producing bio-ethanol from sugarcane, we also capture CO². Through photosynthesis, the sugarcane takes CO² from the air and a portion of this CO² is locked into bio-ethanol. As a result, from the plantation to the final biobased plastic article, more CO² is captured than produced. To be able to make these claims, companies need to perform the so-called Life Cycle Assessment (LCA). This type of study needs to follow international standards and be reviewed by a panel composed of 3 specialists in this field.

Braskem and bioplastics

At Braskem, we are investigating biodegradable solutions, but we will only invest in solutions that improve peoples' lives while promoting positive social and environmental impact compared to the existing alternatives. We also continue to expand our bio-based, recyclable plastic portfolio and plan to fivefold our current bio-based capacity by the end of the decade. We remain convinced of bio-based plastics' green impact, both optimizing natural resources and creating truly circular value chains.

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