The promising biopolymer PHA

Jonathan Salt-Waninge is the PHA expert within Ecoras. For years he has been working on the development of the biopolymer PHA. The fact that PHA is truly biodegradable and, not like other biodegradable plastics (like PLA), only degradable in a composting plant, is what makes it so promising. Jonathan works in several research projects around biopolymer PHA, particularly focusing on its applications. Currently, commercially available PHA from Asia is still being used. While this is a suitable material, it is not preferred for several reasons. One is the fact that this PHA is extracted from sugar or vegetable oils which of course are mainly food crops for humans. Rather, you get PHA from a low-grade waste stream. That’s what Paques Biomaterials has been doing for over 10 years.

Together with TU Delft, they have developed a technology in which they produce PHA from organic waste streams using bacteria. Working closely with five progressive Dutch regional water authorities and the waste and energy company HVC, Paques Biomaterials is currently operating a demonstration plant in Dordrecht under the project name PHA2USE.

What is the biopolymer PHA?

PHA, simply put, is a type of bacterial fat. When people eat too much, the calories not burned are stored as fat. So does this bacteria, but instead in the form of PHA. These bacteria can make PHA from wastewater, sewage sludge, organic waste, in short, from anything biodegradable. A product made from PHA is cleaned up again in nature by exactly the same bacteria. Now of course we are not supposed to throw the products we are going to make from PHA into nature in the future. It is also much better to reuse, recycle or use these products as biomass. The great thing is, for all end-of-life options, these products are safe. If the product does end up in nature, at the very least, it will at least be fully degraded again. The bacteria like to eat their bellies off with that.

Applications that end in nature

This means that both Paques Biomaterials and Jonathan Salt-Waninge of Ecoras are currently working on applications for PHA. They do this both separately in various projects, but also sometimes jointly. But it always involves applications that we find a lot in nature or that have a high chance of ending up there. For example, Paques Biomaterials is working on controlled releaser fertilizers (CRFs) that have a plastic casing. The fertilizer in these CRFs is released sparingly into the soil, but the plastic casing always remains there. By making this shell out of PHA, you prevent plastic from being left behind in nature and thus the spread of microplastics. The same goes for the cleaning brushes that sweep our streets, they also also regularly release pieces of plastic during use. One of the projects Jonathan Salt-Waninge is involved in is Wad van Waarde. They develop bio-based and reusable alternatives for plastic products that often end up in the Wadden Sea. Think of fishing gloves and bags, which will soon hopefully no longer be made of plastic but of linen made from flax. The Wadkop is the reusable alternative to (single-use) plastic cups and bottles, and is made of PHA. Should the Wadkop accidentally end up in the Wadden Sea, it will break down there as well. Because that is also the beauty of PHA. It is biodegradable everywhere, both on land and in water.

A solution to microplastics

Ecoras is also a partner in the Biocooperative North Netherlands to investigate what applications PHA can be used for. PHA is a thermoplastic and may in the future become an excellent alternative to fossil plastics such as PE or PP. Provided that the application does not degrade the material, because PHA is biodegradable. The focus is on industrial applications, which are made with injection moulding. There are already some concrete examples of products made from PHA, such as crates, mugs and laboratory products. But so much more can be done. And this is something that’s going to be explored more and more in the coming years, as interest in PHA grows. Because PHA offers so many possibilities. Just imagine if PHA could replace polyester in clothing and we would soon no longer find microplastics in our water. PHA is really just a kind of polyester, but biodegradable. Besides research, Ecoras also performs environmental impact analyses for the various projects for the applications of PHA. After all, you have to be sure it has a lower environmental impact. Once the applications are there and demand for PHA starts to increase, Paques Biomaterials can produce it in large volumes. This means a lot for circular plastics!

PHA biopolymer by Ecoras

PHA refers to a family of bioplastics made by bacteria in a fermentation process. From this comes bacterial biomass, with PHA contained inside of it (the jar on the left). This can already be used for certain products, but the PHA can also be extracted, separating the PHA (jar to the left of center), and bacterial biomass (jar to the right of center). The biomass can then be utilized.