At the European Bioplastics conference in December, Beatriz Santos of Sustainable Plastics caught up with João Sousa, technology development lead at Paques Biomaterials, a company treading the path towards commercialising production of its PHBV polymer. ‘Consistent effort’ will bring down the cost, he said.
How is the development of PHA at Paques Biomaterials progressing?
We started in 2011, still within the company Paques, which was focused on wastewater treatment and selling treatment plants globally. At that time, we began developing PHA as a way to extract more value from waste streams. In 2021, the decision was made to separate the companies, creating Paques Biomaterials as an independent entity. Our goal is to produce and sell PHA polymers, branded as Caleyda, a type of PHBV.
We use second-generation feedstocks and have conducted many pilot trials, proving that we can produce PHA. Currently, we are engineering our first full-scale PHA plant, focusing on PHA biomass production and stabilization, using process water from a recycling paper mill. In parallel, we are working on the conceptual design of another plant for PHA biomass production, along with an extraction facility capable of processing biomass from both plants. The plan is for all three facilities to be operational by 2027/2028, with product sales beginning in 2028.
What is the planned capacity of your plants?
The first extraction plant will have a capacity of 6,000 tons. We are designing two smaller plants: one at 1,500 to 2000 tons to demonstrate the concept and another expandable from 3,000 to 6,000 tons.
Paques Biomaterial’s technology achieves faster biodegradation due to lower crystallinity. Can you explain this process?
If a polymer is made from only one type of monomer, it aligns well, creating a highly crystalline structure. Adding another monomer creates copolymers, which results in a more open structure because the chains don’t align as neatly. The higher the percentage of copolymer, the more amorphous and open the structure becomes. This allows bacteria and enzymes to access more spots on the polymer, accelerating biodegradation. By adjusting the ratio of crystalline to amorphous materials, we can regulate biodegradation speed based on the product’s application. That's important, depending on the product you want to make.
Your process is very productive: it uses a so-called green solvent and no catalyst. Can you elaborate on this?
While we don’t disclose specific details, our solvent is a green solvent and biodegradable. What we can say is that we take a different approach from the industry, which often uses water-based approaches, which work well for pure cultures. However, we use mixed cultures with diverse bacteria, which can result in slight variations in cell structures. Our green solvent allows us to focus on what we understand: the PHA. It dissolves the PHA, separating it from the cell material, and enables us to clean and dry it efficiently.
What applications are you targeting?
Since we use residual streams, our approach involves a phased introduction to the market. We’ve done tests showing potential for food-grade products, but we’re starting with non-food applications, such as agriculture, horticulture, forestry, and construction. These markets have a strong demand for biodegradable products and have fewer regulatory hurdles, allowing us to establish a market before pursuing food-grade approval.
Are you already receiving expressions of interest from the market?
Yes, we’re actively engaging with companies to generate interest. We currently provide 1-kilogram samples and will scale up to 25–50 kilograms in 2025. We are aiming to get more and more commitment from the market through offtake agreements. We have signed some already, but we need to build up more.
What kind of feedback are you getting?
The polymer seems very interesting for different applications in terms of processing and mechanical properties. One issue we are addressing is the colour effect—it's slightly brownish, which we can remove. This coloration was an artifact of the pilot trials. Some people don't mind it, while others do. From these smaller trials, we know we can remove the colour without additives, just through the cleaning process, resulting in a whitish or light brown appearance. As we work toward producing more consistent materials, colour may become less of an issue. For instance, in thin applications like films, the colour is less noticeable. However, in products like shampoo bottles, the colour is more apparent, which we need to address—especially if the goal is to produce white products. Interestingly, we’ve found that companies focused on biobased and biodegradable materials often prefer a bit of colour, as white can appear synthetic. For now, this niche market is substantial and enough for our first industrial production plants, given the huge size of the plastics industry.
Does using secondary feedstocks give you an advantage over crop-based bioplastics?
Absolutely. Working within the circular economy, we make better use of resources and avoid competing with food crops, which keeps our costs more stable. While competition for waste streams may increase, these feedstocks will always have a lower price level than crops, giving us an economic advantage.
Can you tell us a bit more about the supply chain for the feedstock?
We are pursuing two models. In one, we work with industries that have wastewater issues, helping them build treatment plants that also produce PHA biomass. This is the case of our first plant currently in development with ESKA, a Dutch graphic board producer, part of the RDM group. We then purchase the produced PHA biomass for extraction. In the other model, we collaborate with Looop, a Dutch company that specializes in managing industrial side streams. They supply suitable streams for PHA production, and we process the biomass at our extraction plant. Our approach involves creating hubs, with multiple biomass production facilities feeding a centralized extraction plant. This setup optimizes the extraction plant’s economics, which improve with scale. We’re exploring similar models in other parts of Europe, Japan, South Korea, and Brazil.
The scale of the extraction plant is not that big. Can it be profitable?
Yes, it is similar in size to the first plants built by other PHA producers. The selected scale ensures economic feasibility, providing a solid business case to demonstrate the concept. Larger extraction plants, with capacities of 10,000–25,000 tons, will further improve profitability as we scale up.
In terms of price, our PHA is on par with the other PHAs in the market. We’re still operating at a relatively small scale, which requires a higher price to sustain the business. For now, we’re focusing on niche markets that can accommodate this higher price. These markets are larger than many people realize; the niche market within the plastics industry is actually quite substantial, making this concept viable. To bring prices down, we’ll need to scale up and continue improving the technology. We’re implementing new approaches, and there’s room for decades of technological advancements. We already have ideas in the pipeline for the next 20 years, which will lead to incremental improvements and lower costs.
Whilst price will inevitably become a factor as competition increases, it’s not our main barrier at this stage. However, expanding the business will require addressing cost levels and production expenses. We’re confident we can reduce costs over time. While we’re not at a very low-cost level yet, we see a clear path to achieving it through consistent effort. The key is starting now—otherwise, progress will never happen.
What future do you see for Europe as a PHA producer?
The trend is that production in Europe is declining and moving to places like Asia.
You also see this trend with polyolefins. But I think this is an opportunity for us to kick in: we have unique technologies that allow us to use side streams, which make us independent from agricultural feedstock. Side streams are abundantly available everywhere, also in Europe. So why not make a push within Europe? We now have an opportunity to shift into different materials. We can produce them within Europe. Why would we make the same mistake of letting our production go to other regions completely? At the moment, there's no PHA production in Europe, but there is in Asia and in the US. I think it's also time that we start building up some infrastructure. It’s risky to depend entirely on other regions when we have the capability to produce within Europe.