Processability and commercialisation
Price aside, Ravenstijn also mentioned a few other issues that PHA materials need to address. For example, PHAs generally have a low nucleation density and therefore slow crystallisation rates, which makes them less suitable for injection moulding, as this leads to long production cycle times. Research is ongoing to determine whether and which nucleating agents can be used to remedy this. Molecular chain scission occurs above 160° C and the polymer starts to degrade, which makes low-temperature processing essential.
"This also results in a relatively narrow processing window," he added. Additional problems that need solving include batch-to-batch consistency and the odors arising from contamination with other parts of the cell during extraction.
Ravenstijn further noted that in his experience, it takes a good 20 years or more and upward of $1 billion for a new polymer to become a commercial success. Starting from scratch with a new polymer and going through the stages of development, customer acceptance and production at industrial scale is one of the hardest things to do, he said. This was the case for polylactic acid, and it is what polyethylenefuranoate, another biopolyester that is based on furanic technology and is currently produced at pilot scale by a select number of companies.
Need for value chain alliances
Right now, the PHA market, as such, is only gradually starting to take shape due to the efforts of the players in this market. Aiming to reduce production costs, major investments have been funneled into the development of efficient bacterial strains, fermentation and recovery processes.
While successes have been announced at lab and pilot scale, the step toward industrialisation and commercialisation continues to be difficult. Prominent exceptions are Bologna, Italy's Bio-on SpA, Danimer Scientific, headquartered in Bainbridge, Ga., and Irvine, Calif.-based Newlight Technologies. The latter spent 10 years trying to get the cost of production down, according to co-founder and CEO Mark Herrema. The company developed a proprietary biocatalyst to convert air and greenhouse gases, such as methane and carbon dioxide, into PHA-based plastics at very high yield at scale. The breakthrough came when it discovered there was a control switch that deactivated the catalyst. By turning it off, the company could achieve a 500% increase in yield performance compared to before.
For the first time, here was a process that could outcompete oil-based commodity plastics on price, performance and sustainability. Newlight Technologies has gone on to partner with brand owners — Ikea is one, the Body Shop is another — in the market to accelerate market growth, a strategy that has been adopted by various other PHA producers as well, Ravenstijn said.
"Building strong alliances in the value chain is the only way to bring a new polymer family onto the market," he emphasised.
Danimer Scientific, which entered the PHA space in 2007 with the purchase of intellectual property from Procter & Gamble Co., including Nodax, a medium-chain-length polyhydroxyalkanoate (mcl-PHA), has partnered with PepsiCo and Nestlé.
Italy's Bio-on has set up collaboration and licensing agreements with partners to accelerate the development of new applications and to spread the risk. In 2018, the company announced it entered into partnerships to create specific PHAs for electronics, food packaging, materials and cosmetics.
Build demand before you build capacity is another essential lesson, as several PHA companies have found themselves in financial hot water due to significant capacity underutilisation, he said. It is a lesson heeded by Danimer Scientific, at least: With market volumes finally starting to grow, the company announced in 2018 that it was purchasing the former Alltech algae building, complete with fermentation plant, in Kentucky, where it will produce its proprietary Nodax PHA material using canola oil as feedstock. The smaller players, too, are starting to grow: For example, Kaneka Belgium NV, based in Westerlo, Belgium, also recently revealed plans to expand PHA production to 5,000 tons per year in 2019.