The Wetsus research theme Biopolymers from Water develops and innovates on methods to produce and recover biopolymers, in particular polyhydroxyalkanoates (PHAs). PHAs are a renewable resource and a platform for bioplastics. A core principle of Circular Economy is to use waste, like wastewater and organic residual streams, as feedstocks for renewed products and services. PHA-based bioplastics are inherently biobased and biodegradable for the plastics industry, as well as being recyclable. Through well-controlled microbial processes, PHA-rich biomass can be efficiently generated, and commercial quality polymers can be effectively recovered, enabling this goal of circular resource use. However, current regulations regard valued products made from ‘waste’ resources to still be a ‘waste’ until risks to human health or to the environment are shown to be negligible and manageable. Thus, while a pillar of Circular Economy is to use ‘waste’ as a resource for renewed products and services, in practice such products must still pass ‘end-of-waste’ criteria to be allowed to enter economic circles. Underpinning a societal goal and need for circular economy and, thereby, an end-of-waste, necessitates well-grounded facts and knowledge from risk assessment. Knowledge of risk is a basis for underpinning sound policies and frameworks for resource management and regulations. The entry of ‘waste’ derived PHAs into circular economic supply chains therefore critically depends on methods and approaches to systematically define and predict the risks of a contaminant ‘break-through’ to the recovered PHA. This break-through question depends on the context and details of the recovery process, and knowledge of the likely degree of any contamination of the PHA-rich biomass.
Research challenge
End-of-waste criteria require that risks for unwanted contaminants (‘compound-X’) in the crude product (i.e. the PHA-rich biomass) are managed and that risks (i.e. the probability) for contamination levels in the purified commercial product are defined. The defined risk relates to: (1) the loading and inherent variability of contamination in the crude product (depending on source), (2) the methods of recovery and its characteristic performance curve for controlling and managing contaminant fate, and (3) the safe limits of allowable contamination in the commercial polymers or bioplastics. Safe limits are to be understood in the context of intended types of applications (i.e. toys, food contact, etc). The project seeks to advance understanding of the interactions between process dynamics, contaminant physico-chemical properties, and the fundamental principles governing contaminant fate and removal. The aim is to define risk, the mathematical probability of an unwanted contamination level, and the role of the PHA recovery process, in general, as a gatekeeper in the supply of PHA as a safe and sustainable renewable resource. This strategic project supports the Dutch water authority end-of-waste goals, which are aligned with the 2030 and 2050 Dutch Circular Economy objectives for a national shift to renewable resource supply chains.
Your assignment
The research is inherently interdisciplinary with emphasis on bioplastics, polymer science, chemical engineering, analytical chemistry, and process modelling. Your work will focus on the monitoring and prediction of the fate and removal of unwanted organic and inorganic compounds during the process of recovery of commercial quality PHAs from PHA-rich biomass. You will build on established in-house and knowledge centre expertise, methods and protocols, including solution processing, as well as analyses and protocols such as rheology, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), pyrolysis GC–MS, Fourier transform infrared (FTIR) spectroscopy, High-Performance Liquid Chromatography (HPLC), Liquid Chromatography–Mass Spectrometry (LC-MS) and Gas Chromatography–Mass Spectrometry (GC-MS). In addition, the project entails hands-on laboratory practical research and anticipated field work with ongoing activities of PHA recovery both at laboratory scale and with industrial partner pilot/demo scale up activities.
Your profile
You hold a master’s degree in chemical engineering, polymer science, or a closely related field, and have demonstrated experience with practical testing in materials science, polymer processing, data analysis, analytical chemistry, thermodynamic and/or mass balance testing and modelling of chemical fate and partitioning in different kinds of environments. You have affinity, and interest, in analytical method development, and you enjoy hands-on experimental work. You have a strong self-drive with initiative to explore topics beyond your current expertise, and you are comfortable in multidisciplinary, international, collaborative settings. You are well versed and curious about concepts of statistics and risk assessments, separation techniques in chemical engineering processes, and the use of ‘green’ organic solvents. Written and oral communication proficiency in English is expected.
Keywords: biopolymers; green solvent processing; crystallization; chemical analysis methods; process modelling; impurity tracking; production quality control;
Supervisory Team:
Wetsus supervisors: dr. Alan Werker (Biopolymers from water theme leader, Wetsus); dr. Raquel Barbosa (Scientific project manager, Wetsus)
Project partners: Biopolymers from water
Only applications that are complete, in English, and submitted via the application webpage before the deadline will be considered eligible.
Guidelines for applicants: https://phdpositionswetsus.eu/guide-for-applicants/
