The global dependence on petroleum-based plastics has generated an environmental crisis that requires solutions based on the circular economy. One of the most promising alternatives is the production of polyhydroxyalkanoates (PHA), bioplastics of natural origin synthesized by bacteria that act as an energy reserve . The industrial doctoral project between the company Benviro , Eurecat and the Autonomous University of Barcelona (UAB) focuses on optimizing the transformation of organic waste into this high-value-added material.
The production of bioplastic from waste is not a direct step, but a chain of biochemical processes where microorganisms are the protagonists. Despite the potential of the process, there is a critical technical limitation: hydrolysis . Many agro-industrial waste contains complex macromolecules that bacteria cannot digest directly. This stage of “breaking” the organic matter into simpler units (monomers) determines the speed and efficiency of the entire system. If hydrolysis is slow or incomplete, the production of bioplastic drops drastically.
This collaboration represents a step forward in waste management in Catalonia. By transforming underused agro-industrial by-products into valuable resources, the project not only reduces greenhouse gas emissions associated with landfills, but also promotes a more sustainable chemical industry that is decoupled from fossil fuels.
"Committing to an industrial doctorate in this context allows me to combine applied research with industrial reality, generating a tangible environmental impact."
To learn more about the research and what the experience was like, we spoke to biotechnologist Montserrat Jiménez Urpi , who is leading this industrial doctoral project focused on optimizing the production of polyhydroxyalkanoates (PHA) from agro-industrial waste. With the project, the industrial doctoral student has validated the scaling up of hydrolysis and fermentation processes to a 400-liter pilot plant. This initiative not only promotes industrial circularity, but also guarantees the production of bioplastics with mechanical properties suitable for high-performance sectors such as cosmetics or luxury packaging.
Passion for industrial production and environmental impact
– Montserrat, you are a biotechnologist and fermentation specialist. Many similar profiles opt for the pharmaceutical or traditional food industry. What motivated you to opt for an Industrial Doctorate focused on the revaluation of waste?
– Since I finished my degree, I was clear that the branch that I was most passionate about was industrial production, especially processes where the control of fermentation conditions and the optimization of operating parameters are key to efficiency. The Benviro project allows me to transform waste into high-value-added products, combining applied research with market reality. Committing to an industrial doctorate in this context allows me to combine applied research with industrial reality, generating a tangible environmental impact.
– Working with agro-industrial waste involves managing “imperfect” raw materials. What attracts you to this challenge? – Precisely the fact of giving value to what, at first glance, seems to have none. We do not limit ourselves to conventional strategies such as biogas; we go one step further to obtain volatile fatty acids (VFAs), which are the basis for producing bioplastics. We turn an environmental management problem into a business opportunity.
The science of "cooking" waste for bacteria
– Your project focuses on hydrolysis and acidogenic fermentation. How would you explain this process to a non-scientific person?
– We could say that we are “cooking” food for the bacteria. Real waste is too complex for microorganisms to quickly utilize. With hydrolysis, we obtain smaller, more easily assimilable molecules. Then, through acidogenic fermentation, the bacteria transform this food into AGVs, which will ultimately serve as a substrate for other bacteria that produce the bioplastic PHA.
– What is the main innovation you propose to maximize this production?
– The first step is to understand well what type of waste we have, because not all of them are the same. They are real waste, which has variability, and for this reason it is necessary to characterize them and identify their main components to design a hydrolysis strategy (the part of “cooking” the waste) appropriate to the type of waste and focusing on the fraction that will be most difficult for bacteria to exploit.
Once the residue is hydrolyzed, the next challenge is to adjust the fermentation conditions specifically for each type of residue, instead of applying the same standard process for all. We have some reference parameters, but we adjust it according to the specific characteristics.
The main innovation of the project is precisely this approach: adapting both hydrolysis and specific fermentation to real waste, according to its characteristics, instead of applying a standard process. But always with an industrial vision, prioritizing truly scalable strategies applicable to large production volumes.
"Five years from now, we firmly believe that the use of biodegradable and microplastic-free materials will not be a differentiating element, but an indispensable requirement for most industrial sectors."
The competitive advantage for Benviro
– Benviro already has a patented technology. Why is it strategic to invest resources in a thesis on an initial phase like hydrolysis?
– Like most industrial companies, we seek to maximize production while minimizing costs. The Industrial Doctorate has allowed the company to increase the ratio of kilograms of AGV produced for each euro of investment. The more waste we utilize at the beginning, the more bioplastic we generate at the end, which optimizes the entire business model.
This is why hydrolysis is a key part of the overall process, not only to improve fermentation but also to improve the productivity of the final bioplastic. In short, the industrial doctorate has allowed us to design, optimize and validate a more sustainable business model.
– How is this optimization translated into the final product that reaches the market?
– When we talk about real applications, the optimization of initial processes, such as hydrolysis and fermentation, translates directly into control, yield and quality of the final product, which are critical factors for its industrial adoption.
Control of the initial phases gives us traceability over the structure of the PHA polymer. This allows us to control the mechanical properties of the bioplastic and reduce deviations between batches, making it suitable for demanding sectors such as premium packaging or cosmetics, where the material must be reliable and comparable to fossil plastic.
– Scaling up is one of the big challenges. How has the transition from laboratory reactors to the pilot plant been?
– It is a complex process because what works on a small scale is not always economically or technically viable on a large scale. Despite this, we have successfully scaled up to a 400-liter reactor. We have had to manage higher volumes and adapt operating times; processes that take 30 minutes in the laboratory can take 3 hours in the plant.
– Can you describe any critical moments in managing residue variability?
– In one case, the waste varied every two days according to the original production cycle, detecting deviations in the analysis. We solved this by incorporating an auxiliary homogenization tank to mix waste from different days, creating a robust and industrially viable process despite the variability inherent in the raw material. In this sense, a key part of the project has been learning to work with real waste, assuming and managing the variability inherent in its origin, and translating it into a robust and industrially viable process.
The two-way bridge between the university and the market
– What does this doctorate contribute to the GENOCOV research group and to Eurecat?
– It has been the lever to close the circle between laboratory knowledge and plant reality. Access to real operating data and costs allows us to prioritize what is scalable and has industrial return. Without the alliance with Venvirotech, we would have had difficulty validating protocols with real CAPEX and OPEX restrictions. It has provided us with transfer speed and technological maturity (TRL).
– How is knowledge transfer managed to make a production plant viable?
– The transfer has been a continuous flow: the scientific results were immediately transformed into operational and design criteria for the pilot plant. We have defined the bases of the process (P&ID, selection of materials) so that the knowledge does not remain only in publications, but in real operational capacity.
– Do you believe within the project team that the production of PHA from waste will be the industrial standard?
– We have no doubt about it. European legislation is already pushing towards the reduction of fossil plastic and we will probably see taxes on virgin plastic. In five years, the use of biodegradable materials will not be a differentiating element, but an indispensable requirement for sectors such as agriculture or food packaging. We are working to make this transition technically viable and scalable.
– What advice would you give to someone who is hesitating between an academic career and industrial research?
– Industrial research offers an environment much closer to reality, where each decision has a technical, operational and economic impact. In my case, all research has always focused on the possible implementation of the studied process in an industrial plant.
This implies that not only is the best strategy sought from a scientific point of view that seeks to maximize hydrolysis or fermentation yield, but also one that can actually be applied, scaled up and maintained in a production plant. For me, industrial research is ideal for those who want to transform scientific knowledge into real and tangible solutions.
