CO2 converted to bioplastic on a large scale: Photanol plant Delfzijl takes new step

For more and more people, trust in a brand increases when products are produced sustainably. At biotech company Photanol, the positive contribution to a sustainable society can literally be seen: the cyanobacteria with which the demonstration plant in Delfzijl works literally extract CO2 from the air and turn it into useful substances. From raw materials for plastics to material for use in 3D printers: you can think of anything the bacteria can be used for. In cooperation with Akzonobel, the Amsterdam start-up recently built a demonstration plant in Delfzijl, next to an Akzonobel Nobian factory. Photanol will eventually use the CO2 from the AkzoNobel plant's smokestack as raw material, or as 'feed' for the blue-green algae bacteria.

The demonstration plant took an important next step in the process last week: for the first time, the plant is working with cyanobacterial strains that use sunlight to convert CO2 into a specific type of acid: lactic acid. This is an important component for bioplastics, among other things. "Last year we tested the systems with the so-called wild type of cyanobacteria. That grows and behaves the same but does not make lactic acid," Koekoek adds. "We have already proven in the laboratory for a long time that the technique works. Now it is time to show the outside world that we also have the production process under control on a large scale and that it is profitable," says Koekoek, who is enthusiastic about working with the cyanobacteria. "It's a beautiful process to see. Every day you see the green soup in the reactor changing color a little bit." Eventually, the substance should become green enough to catch enough sunlight to efficiently produce lactic acid.

How exactly does that work, such a "blue-green algae factory"?

Photanol's specially cultivated cyanobacteria convert CO2 and sunlight into organic acids through photosynthesis. Those acids, in turn, can be used to make bioplastics, as well as cosmetics or products in the chemical industry. At the plant, a green soup of the bacteria is pumped around in a reactor, to which sunlight, water and nutrients are added, among other things. These are ideal conditions for the blue-green algae and multiplication is rapid: every day the number is doubled.

Sterile environment

Next time, the plant will focus on, among other things, making the environment in which the bacteria grow more sterile, or "contamination control. "We create such fine conditions in our plant for our bacteria that they can produce quickly. But other bacteria also like those conditions, and they sometimes grow even faster than our own." The trick is to favor the strains from the lab. There are several ways to do that, Koekoek explains. "For example, some bacteria don't handle high temperatures well. What you can do then is let the reactor get very hot from time to time, so the cyanobacteria just survive but other bacteria don't."