Projects of the iPRACS research group

Abstract

Polyurethane (PU) foams are all around us, from our walls to our beds and our cars. Only 20% of this PU is recycled, primarily into inferior products. Polyurethane is a heteropolymer of a polyol and a diisocyanate, mostly forming networks. It is well-understood that these monomers can be cleaved using various chemical recycling techniques, but only pilot plants using mattresses as feedstock are currently operational. To limit the complexity and avoid the difficulty of end-of-pipe purification, the foams should be sorted prior to recycling. Sorting based on isocyanate type can be done using near-infrared identification, due to limited isocyanates industrially used. However, the polyols used in PU are very diverse, limiting sorting possibilities. To enable sorting based on polyol, I propose to tag the polyols with a spectroscopically detectable tag. The tags proposed in this research are fluorophores. This research will provide a proof-of-concept that fluorescent tags can be attached to polyols and used to identify that polyol in PU foam. This will be done by synthesising functionalised tags, comparing different methods of attachment, followed by investigating the properties, stability and recyclability of foam with tagged polyols. This will provide applicable basic tag structures and an optimised screening method to find more tags that are suitable for PU foam. After implementation, this will lead to higher quality recycled polyols and an increased foam circularity.

Researcher(s)

• Promoter: Billen Pieter
• Co-promoter: Vande Velde Christophe
• Fellow: Cassimon Jonas

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Polyurethanes (PU) are widely used in mattresses, upholstery, furniture, automotive, construction, and insulation. They are mostly thermoset foams, made by reacting isocyanates (MDI, TDI, or HDI) with polyols. Their thermoset nature limits mechanical recycling, making chemical recycling crucial for circularity. The resulting aromatic molecules, ureas, amines and polyols from depolymerization have varied physicochemical characteristics, impacting separation during recycling. This doctorate aims to use thermodynamic modeling tools to predict the ease of separating depolymerized PU mixtures. Methods include activity coefficient based models (NRTL, UNIFAC, HANSEN) that are accompanied by computational chemistry methods to optimize the models and fill in unknown gaps. Modeling results will inform engineering software for process design, optimizing recycling for recyclers and informing circular design for PU formulators and recyclers. The focus is primarily on predicting interactions between different polyols used in PU, considering monomer composition, degree of branching, molecular weight distribution, and functionality, to facilitate efficient separations. Later, other constituents are covered in more detail as well. The goal is to provide recyclers and formulators with insights for process optimization and improved circularity of PU materials.

Researcher(s)

• Promoter: Billen Pieter
• Co-promoter: Cunha Ana
• Co-promoter: Nimmegeers Philippe
• Fellow: de Graaf Christophe

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

(Bio)chemists think about molecules in terms of connectivity and spatial structure. These concepts match well with the actual structure of molecules on the nanoscale. Based on irradiation with a wavelength in the order of magnitude of the interatomic sizes (x-rays) in a periodically ordered structure (a crystal), from the diffraction pattern, the underlying structure can be calculated. Since the '80s this is a standard technique for experimentally visualizing molecules. The importance of it is impossible to overestimate – a majority of the 3D information about atoms and molecules, from molecules consisting of a few atoms to proteins and even complete cell organs like ribosomes, stems from x-ray diffraction measurements. The technique is of incredible importance both for the unambiguous characterization of newly synthesized small molecules, including their stereochemistry, as well as for macromolecules like proteins, and their complexes with pharmacologically active compounds. This allows to elucidate drug and disease mechanisms. This project concerns the purchase of a modern x-ray diffractometer, which will allow to obtain this information faster, with better quality, close to the research involved, and in-house. This will lead to a substantial acceleration within these research topics, to new cooperations both within and outside UAntwerp, and to the initiation of new research, by making this technique broadly available and easily accessible.

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Maes Bert
• Co-promoter: Meynen Vera
• Co-promoter: Sterckx Yann
• Co-promoter: Van Der Veken Pieter
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Polyurethane (PU) foams are a key constituent in mattresses. To date, only 20% of this PU is (mechanically) recycled, primarily into inferior products. Polyurethane is a heteropolymer of a polyol and a diisocyanate, mostly forming networks. The polyols used are can be very diverse, even within a single mattress foam formulation. It is well-understood that these monomers can be cleaved using various chemical recycling techniques, but only pilot plants using mattresses as feedstock are currently operational. To limit the complexity and avoid the difficulty of end-of-pipe purification, the foams should be sorted prior to recycling. Sorting based on isocyanate type can be done using near-infrared identification, due to limited isocyanates industrially used. However, the polyols used in PU are very diverse, limiting sorting possibilities. To enable sorting based on polyol, we propose to tag the polyols with a spectroscopically detectable tag. The tags proposed in this research are fluorophores. This research will provide a proof-of-concept that fluorescent tags can be used to identify polyols in a PU foam. This will be done by mixing tags into polyols, analysing how functional the tag is in the polyol, followed by making a foam out with these tagged polyols and testing the detectability of the tags in a foam. Further, an in-dept investigation of the properties of the tagged foam and an evaluation of the recyclability of foam with tagged polyols is conducted. This will provide applicable basic tag structures and an optimised screening method to find more tags that are suitable for PU foam. After obtaining a working proof-of-concept, the technology will be patented and PU additive manufacturers will be approached for scale up and bringing it to market. After implementation, sorting of foams based on the polyol can become trivial. With this sorting capabilities, better recycling strategies can be implemented such as justified decisions which foam will be mechanical recycled and which chemical. This will lead to higher quality (virgin-grade) recycled polyols and an increased foam circularity.

Researcher(s)

• Promoter: Billen Pieter
• Co-promoter: Vande Velde Christophe

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Circular economy strategies are gaining attention within companies to reduce their environmental impact and meet government targets. In this context, companies in different sectors are investigating and implementing different strategies to reuse, repair, refurbish, remanufacture, reuse, recycle and recover end-of-life products, components, parts or materials. Deciding which strategy to choose requires case-specific life cycle and techno-economic assessments, which typically require a lot of data, expertise and time. Furthermore, there is no single quantitative definition of circularity that can be directly used to assess, monitor and optimize the circularity of product designs or value chains. Therefore, there is a need for generic tools/methods that can be used to assess circularity based on generic information that is commonly available. To address this knowledge gap, we present three central hypotheses, in which we argue that energy consumption provides an adequate projection of circularity and that entropy is a valid parameter to move from process-specific assessment methods to more generic state-based assessment methods: Hypothesis 1: The relationship between the embodied energy of materials and products and their carbon footprint is linear. This has already been demonstrated in several studies, Hypothesis 2: The relationship between the embodied energy of materials and their economic value (as raw materials) is linear. This has already been demonstrated by the work of Tim Gutowski and others. Hypothesis 3: The relationship between resource dilution (reciprocal concentration in deposits) and embodied energy of materials is linear. Dilution here can be interpreted directly as entropy, cf. the description above. This has already been demonstrated for metals, while we have calculated a similar relationship for post-consumer packaging waste in preliminary work. Evidence supporting these three hypothesis would for the first time establish a direct and quantitative link between materials circularity and climate change. That way entropy can be used as a proxy for energy expenditure over the life cycle of a material, and in turn for the carbon footprint. We would further provide basic evidence, that can convince companies and policy makers using simple case studies. In this project, we will further demonstrate hypotheses 2 and 3, by focusing on the value versus entropy of waste materials, and by looking at bioresources. As a result, using this framework, waste sorting and (bio-)refining processes can be judged on the performance of individual unit operations rather than only on the end results of a complete plant configuration. The scope for this project will be restricted to different fossil-based polymers and bio-based polymers, to ensure feasibility and complementarity with the group's expertise. The anticipated results will accelerate the deployment and valorization of the novel circularity assessment methodology and make it more accessible to the main target audience, i.e. product and process designers. In this way, the foundations will be laid for a circularity quantification and optimization tool based on generic thermodynamic principles.

Researcher(s)

• Promoter: Billen Pieter
• Co-promoter: Nimmegeers Philippe

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Develop a novel chemical recycling approach to process rigid polyurethane (PU) and polyisocyanurate (PIR) end-of-life materials. By using selective depolymerization, we will transform these wastes into valuable building blocks to produce more sustainable materials, guaranteeing in this way a high carbon circularity. To secure the sustainability of the new technological route, CHRONICLE will also have a strong value chain management supported by techno-economic and life cycle assessment. CHRONICLE will link waste providers and recyclers, with downstream chemical companies and PU producers, resulting in an optimized value chain with enhanced circularity, new economic opportunities and new synergetic partnerships. CHRONICE is a part of the Moonshot program, where VITO, KUL and UA join forces. (2023-2027).

Researcher(s)

• Promoter: Billen Pieter

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Nucleation - the start of crystal growth - is a key concept in making solid materials. Since an important part of solid state properties is related to crystal size and shape, it is there that reliable and consistent nucleation is of crucial importance, to make sure that any subsequent crystallization process is reproducible. Variations in nucleation behavior of e.g. a cooling solution can result in a batch of material with completely different properties. In 1996 an unexpected observation was made of crystals starting to grow in solutions that had been irradiated with a powerful laser pulse - non-photochemical laser induced nucleation (NPLIN). Ever since, researchers have been trying to chart this phenomenon and the parameters that influence it, but working reproducibly with supersaturated solutions is difficult, and hence it is even harder to obtain statistically relevant data that demonstrate clear correlations between a given parameter and NPLIN. This project proposes a radically new approach to this problem: a micro-flow reactor, in which very large numbers of tiny liquid packets can be sent past the laser focus, in order to collect an unprecedentedly large number of data points in a parameter study. This new approach will enable the identification of the underlying mechanism(s) of NPLIN, which to date have remained elusive.

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Wenseleers Wim

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Rubbers, although widely used in society, are traditionally difficult to recycle. Most commercial recycling techniques are restricted to granulation, although the products of this process have low value and are under environmental scrutiny. State-of-the-art devulcanisation and/or pyrolysis of rubbers are associated with very high costs, and lead to an ill-defined array of products. However, for a long time tyre, degradation studies have unknowingly shown us a different way of depolymerisation, that is ozonolysis. For the first time, its potential as a recycling technique has been identified instead of being a nuisance to be avoided. Ozonolysis will be used as a novel, sustainable approach to potentially derive telechelic resins from rubber waste. In this project the various challenges regarding mass transfer, characterisation, work-up and scale-up will be overcome in order to provide recycled resin samples and recovered carbon black to industrial stakeholders, while establishing a functional lab scale reactor setup to attain this goal. Furthermore, the obtained resins will be characterised and employed in final demo-applications of new polycondensates as well as adhesives. Starting from recalcitrant (sometimes bio-based) waste, this green and relatively cheap oxidation method can therefore yield products with interesting, new properties, and at the same time off-set fossil-based source materials.

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Billen Pieter
• Fellow: Fishel Yanou

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Most chemical reactions in the cell have high activation energies, and without enzymes, they would not occur with the required speed for biological processes. Hydrogen bond donors (HBD) as Lewis-acid-catalysts play a key role in many enzymatic reactions, both in orienting the substrate molecules and lowering barriers to reaction. Their tendency to undergo self-quenching however, decreases both solubility and reactivity. Supramolecular chemistry under the form of MOFs offers a promising biomimetic platform for immobilizing these catalytically active sites, and features defined structure and high porosity. Previous attempts have been less than successful due to limited substrate scope and small pore size, instability and complex synthesis. Here, we propose a new method with three goals: 1) pre-design large pore MOFs to lock in the desired porosity and stability, 2) extend linker size to achieve large pores by using direct arylation reactions to decrease synthetic complexity, and 3) propose several alternatives to add (combinations of, as well as chiral) HBD catalysts to the MOF framework. These materials can be used as templates for metal/carbon hybrids with unprecedented porosity. Finally, all materials will be tested for catalytic activity. This modular and concerted synthetic approach towards heterogeneous (organo)catalysts will re-start a direction of research in which the spectacular advantages offered by addressing the main issue with existing HBD catalysts are obvious.

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Billen Pieter
• Fellow: Esrafili Dizaji Leili

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

The continuously rising demand for resources is pushing us to exceed the planetary boundaries. At present, methods as life cycle assessment and techno-economic assessment have been proposed to develop sustainable systems and processes. However, these traditional methods do not allow us to predict the sustainability of disruptive technologies starting from a blank canvas, as these rely on very specific information that only becomes available at higher technology readiness levels (TRL) and a background system. Hence, methods are needed that solely rely on generic information available at any TRL. This is exactly what I aim to achieve in this research project: I will create an innovative design-for-sustainability paradigm that can deliver forecasts and can optimize the development of novel processes and systems in view of economic and environmental sustainability at any TRL. To this end, I will connect statistical entropy to generic energy calculations and generic capital cost estimates and I will define multi-objective optimization problem formulations and solution strategies. As validation, three applications will be studied: (i) the design of lignocellulosic biorefineries, (ii) polyolefin plastic waste management and (iii) phosphorous management. The proposed groundbreaking research will open avenues towards my future career as an independent academic principal investigator working on process-based modeling, control and optimization for the development of sustainable systems.

Researcher(s)

• Promoter: Billen Pieter
• Co-promoter: Van Passel Steven
• Fellow: Nimmegeers Philippe

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

This Baekeland project will lead to a novel method of recycling rigid polyurethane foams in a close collaboration between SurePUre (Triple Helix BV) and the University of Antwerp, in the form of a shared doctoral trajectory. Current processes recover only a single-phase mixture, which are low-grade polyols with limited utility. There is, however, a strong need to replace today's petrochemical PU feedstock. This project aims at recycling the main PU constituents separately, and therefore creating more value to a circular economy.

Researcher(s)

• Promoter: Billen Pieter
• Co-promoter: Vande Velde Christophe
• Fellow: Porters Matthew

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Plastics are an integral part of our daily lives, however, they are difficult to recycle. Nevertheless, the diversity of polymeric materials is still increasing, despite societal and legislative pressure to reduce their complexity. Unfortunately life cycle assessment and techno-economic assessment always start from enthalpic considerations, i.e. material and energy balances, rather than entropic considerations, i.e. product complexity and structure. This leads to the paradoxical situation that we do not know which waste material is of enough high value to recycle taking into account any (future) market conditions, and that we do not exactly know how to produce plastics to optimize the value of post-consumer recyclate. Moreover, the (macro)molecular level, which determines macroscopic properties, is never addressed, although it is well-recognized that industrial polymer synthesis is characterized by significant inter-and intramolecular variations. A linking of polymer reaction eng (PRE; Ghent University expertise) and generic sustainability assessment (SA) methods (University of Antwerp) is thus almost absent but highly recommendable, justifying the scope. We aim at a generic method for the prediction and optimization of the recyclability of economic goods starting at the molecular level. In the long run the method can predict on the fly whether chemical modifications are not only worthwhile application wise but also in view of recyclability.

Researcher(s)

• Promoter: Billen Pieter
• Co-promoter: Nimmegeers Philippe

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

The project concerns chemical recycling of vulcanized latex foams (i.e. foam rubbers) through a novel method to generate smaller telechelic oligomers, making a start on elaborating possible reaction conditions and the characterization of the products.

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Billen Pieter
• Fellow: Fishel Yanou

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Polyurethane (PUR) as a thermohardening polymer is difficult to recycle - two current techniques are mechanical recycling (cutting and rebonding) and up to a certain limit also chemical recycling, in which the polyol component is recovered through hydrolysis, alcoholysis or glycolysis. The isocyanate component, however, reacts to amines, for which the current state of the art is to incinerate them. In this project, an alternative route is researched to generate isocyanates from this remaining fraction, without use of toxic or environmentally unfriendly reagents, to close the material loop regarding the use of polyurethanes in a sustainable manner.

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Billen Pieter
• Fellow: Nees Marthe

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

This project aims to recycle post-industrial polyurethane (PU) waste, i.e., production waste, scrap and/or poor-quality PU containing more than one polyol as a three-phase system, which we have recently observed for the first time in our laboratory. Using this technology, different polyols can be recovered separately with higher purity than the current state of the art chemical recycling. Currently, this post-industrial waste is either incinerated or, at best, mechanically recycled into low-value products. With our strategy, all polyols will be fully recovered and reused in foam production. In the medium term, this should lead to small modular polyol recovery units. In addition, the project will produce amines in a one-step recycling process and separate them in a less energy-intensive process. An important operational objective is to apply this concept to different types of PU waste containing more than one polyol from different production units.

Researcher(s)

• Promoter: Billen Pieter
• Co-promoter: Vande Velde Christophe

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

The circular economy action plan adopted in March 2020 is one of the main building blocks of the European Green Deal that aims for the EU to become climate neutral by 2050 and to reduce other environmental impacts (e.g. nitrogen pollution, air pollution, biodiversity loss). The circular economy will require the increased utilization of residual streams (e.g. wastes and side streams) by creating new high value products from them. This may include the production of fertilizers, proteins or construction materials from waste streams as well as the substitution of fossil-based plastics by renewable alternatives. However, in pursuing the circular economy, it needs to be ensured that the environmental impacts of the novel goods are indeed lowered or that environmental impacts are not simply swapped between impact domains. In addition, by reusing waste streams new methodological challenges for the environmental assessments emerge including how to account for the impacts of waste generated upstream, what the systemic impact of new value chains based on waste/side stream products is and how to account for the difference in the quality of recyclates as compared to virgin materials. The objective of the MAZE project is to develop novel methods and approaches to improve the (prospective) evaluation of environmental impacts of products in the circular economy. The principal methods to be used in the project are life cycle assessment and material flow analysis. The research will address how upstream impacts of waste products can be accounted for, how product quality can be evaluated in environmental and material flow assessments and subsequently how information can be used in prospective decision making. Methods will be applied to a selected number of biobased materials/products to demonstrate their applicability. Thereby, outcomes of the project are in strategic alignment with the EU's circular economy action plan.

Researcher(s)

• Promoter: Nimmegeers Philippe
• Promoter: Spiller Marc
• Co-promoter: Buyle Matthias
• Co-promoter: Nimmegeers Philippe
• Co-promoter: Spiller Marc

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Plastics are versatile and paramount in our daily lives. However, this versatility makes plastics difficult to recycle due to their complexity in terms of geospatial distribution, substance/monomer/oligomer composition and molecular distribution. This complexity, later referred to as entropic considerations, is barely acknowledged in the traditional, state-of-the-art recyclability and sustainability assessments such as life cycle analysis (LCA) and techno-economic assessment (TEA). And yet, in order to design recyclable and therefore sustainable materials, and implement supporting policy, having this knowledge via an easily accessible methodology is imperative. Polyurethanes (PU) are highly versatile polymeric materials used in a plethora of applications. To date, the main end-of-life waste management steps for PU are incineration and landfilling, with only limited recycling. Therefore, I will study the following research question: "How does the complexity of polyurethanes affect the recyclability of related applications, and how can we quantify this?". In this blue sky small research project, I combine my expertise on statistical entropy analysis and generic recyclability predictions with the expertise on chemical recycling of plastics at the iPRACS research team to: (i) develop a generic methodology for the evaluation of the recyclability of plastic waste including information on the compositional complexity, complexity in terms of geospatial distribution of products over society and monomer composition and molecular distributions based on MSEA and (ii) validate the methodology by quantifying the limitations to the recyclability of PU. The resulting fully validated recyclability assessment paradigm will serve as a stepping stone for my independent research track. The proposed research project could give sufficient demonstration of the methodology to make it accessible for future applications and projects.

Researcher(s)

• Promoter: Nimmegeers Philippe

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

The NuCryPept-control project aims to create tools for the simplification of parameter-space exploration in the development of oligopeptide nucleation and crystallization. We are developing precise and accurate control technologies for various parameters in the crystallization process (pH, composition, concentration, temperature) that not only work on microscale, but in addition are scalable, so that the same technologies used for screening can also be applied in manufacturing to unburden, through crystallization, the purification process of biomacromolecules, which is currently expensive and inefficient.

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Hereijgers Jonas

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

This project concerns the synthesis of linkers for MOFs and the MOFs themselves, to be used as transition metal catalyst scaffolds. A number of organic molecules with specific topicity are synthesized to form MOFs with channel-like pores in combination with certain metals or metal-oxygen clusters. These MOFs are suitable for pore-expansion by lengthening the linkers, for which a number of strategies are proposed in the project.

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Meyer Nathalie

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

ChemReRub is a project that aims to recycle natural and synthetic rubber, a recalcitrant waste material of partly natural origin, into high-value chemical feedstock for use in various applications, in order to get away from the classical strategy of energy recuperation.

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Billen Pieter

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

This project aims at the complete recycling of polyurethane waste, by a two stage procedure in which both polyols and isocyanates are recovered. With respect to state-of-the-art technologies and concurrent research initiatives, this project targets production of isocyanate fractions from waste via a shorter route, without prior production of amines. An important operational goal is the development of a new lab scale custom reactor setup, next to the testing on actual polyurethane waste samples.

Researcher(s)

• Promoter: Billen Pieter
• Co-promoter: Vande Velde Christophe

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

The series of lectures is structured around three important production and consumption chains that largely determine the footprint of the modern consumer: energy, materials and food. For each of these three chains, the international context and evolution is outlined. Critical elements in the chains are examined with a closer look at production, consumption and disposal. The lectures are illustrated with cases from own research.

Researcher(s)

• Promoter: Billen Pieter

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

This project provides an innovative, new and different way of recycling post-consumer rubber, not as granulates, but as valuable feedstock for the production of recyclable polymers. Two important contributors in Flanders are recycled tires and latex mattresses. The purpose of this project is to bring the recycling technology from initial concept stage to a laboratory demonstrated process with poly-diene rubbers being recycled into starting materials for recyclable condensation polymers, preferably with ground rubber tire material as feedstock.

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Billen Pieter

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Natural rubber is a biopolymer with many applications, but its recycling and reuse are an especially challenging problem. Until now, the most prevalent waste treatment method for rubber is either burning or landfills. Devulcanization of the rubber, necessary for for its reuse as an elastomer, is extremely difficult. Use of rubber as a green feedstock, after a useful life as an elastomer, has hardly been explored. Ozonolysis is a polyvalent technique that finds application in cutting C=C double bonds in a polymer and creating terminal functionalities where the chain has been cut. In this way, it must be possible to depolymerize natural rubber to use as feedstock for other condensation polymers that are easier to recycle than rubber itself. This, then, is the threefold goal of this project: 1. Depolymerization of rubber – latex foam and ground rubber tire- into oligomeric materials with terminal functionalization, and researching the influence of the process parameters of ozonolysis on the properties and chain lengths of these materials. 2. Researching the fate during this process of the cross-links that are created in natural latex during vulcanization. 3. Using the example of rubber as a case in the development of LCA and TEA tools, and provide real-time feedback from these studies to this project with regard to the use of certain chemicals, solvents and the general technical-economic feasibility of the process during its development.

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Billen Pieter
• Co-promoter: Pazdur Lukasz

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

In this project iPRACS collaborates with the crystallization group at Janssen Pharmaceutica to study novel ways of nucleation in supersaturated systems, that can be applicable to pharmaceutically active compounds, in order to better control their solid forms.

Researcher(s)

• Promoter: Vande Velde Christophe

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

The proposal concerns versatile instrumentation for determining crystallinity, unit cell size and structure of organic, metal-organic and inorganic materials. Several groups at UAntwerp have a pressing need for fast, reliable, X-ray diffraction data, at low angles to determine large unit cells, and preferably in 2D to determine sample homogeneity. The envisaged machine has a Cu K alpha source, horizontal sample platform (Bragg-Brentano geometry), capability for measuring down to low angles (theta = 0.5°), and a fast and sensitive 2D solid state area detector. It will be used for materials research and characterization in inorganic porous materials (zeolites, templated silicas and titanias), metal organic materials (crystalline metal-organic frameworks), organic materials (fatty acids, PUR building blocks) and identification and characterisation of pigments for study and conservation of old masters' paintings. In addition, through the use of the PDF (probability density punction), the machine can generate experimental information through x-ray scatterineg on average short-range order in non-crystalline materials such as glasses and amorphous powders.

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Billen Pieter
• Co-promoter: Cool Pegie
• Co-promoter: Kiekens Filip

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Based on the recently developed "physico chemical separation methods", a process will be developed that allows to reduce the level of oxygenates and nitrogenates in pyrolysis oil and increasing it valorization potential. The process can be a substitute for hydrotreatment.

Researcher(s)

• Promoter: Billen Pieter
• Promoter: Tavernier Serge
• Co-promoter: Billen Pieter
• Co-promoter: Perreault Patrice

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Everybody today has heard about the increasing need of having cheap, environmentally sustainable and green processes. The world is full of these high-sounding and fancy terms, but how to achieve them in practice? There are several ways to improve a chemical process, but most often studies are based on catalysts: the "accelerators" of chemical reactions. Catalysts are expensive, suffer from low stability and are difficult to separate/reuse, but their role is vital for pharmaceutical, agro and fine chemical industries. The immobilization of the catalysts on a support can solve all the mentioned problems. We propose a scaffold which has never been used before: Metal Organic Frameworks (MOFs). MOFs are networks made by ion metals and rigid linkers. Under appropriate conditions these two parts can assemble a porous material on which we can immobilize the catalysts, making possible their recovery/reuse at the end of the process. The advantages of our scaffolds are immense: uniform, reproducible and controllable manufacture and the possibility to completely engineer the linkers. As a consequence, we can control the whole network structure: we can personalize it, giving new properties to the walls, and tuning the pore size. In other terms: modular haute couture, for the need of the mentioned chemical industries. If you were an industrial stakeholder, wouldn't this sound great to you?

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Cool Pegie
• Fellow: Fucci Rosa

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Natural deep eutectic solvents (NADES) show great promise as media for enzymatic reactions in sectors where (bio)compatibility with natural or medical products is a must. Whereas in theory they can be tailored to the envisioned reaction, ensuring optimized yields, to date the knowledge is predominantly empirical, with some mechanistic reports giving a fragmented view at best. Therefore, even merely explaining experimental observations is not straightforward, let alone making predictions. This doctoral study aims at building a structured, holistic understanding of the effect of NADES media on enzymatic reactions, whereby effects on solubility, solvation, viscosity, inhibition and denaturation will be distinguished. The solubility, solvation energy and viscosity will be predicted by first principles and molecular dynamics calculations, serving as input for a group contribution model using machine learning. Experiments will train and validate the model, and learnings from observed reaction kinetics will be further benchmarked against molecular dynamics calculations of enzyme structures and interactions in NADES. Structural changes of the enzyme will be demonstrated using Raman optical activity spectroscopy. The combination of these methods ensures fundamental knowledge acquisition, while the group contribution model is part of a structured methodology. The findings of this project are transferable to other uses of NADES.

Researcher(s)

• Promoter: Billen Pieter
• Co-promoter: Cornet Iris
• Co-promoter: Neyts Erik
• Fellow: Kovács Attila

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project type(s)

• Research Project

Abstract

Polyurethanes (PU) are versatile group of polymers, being used increasingly in diverse applications; for instance in mattresses, building foams, automotive and adhesives. PU is a cross-linked polycondensation polymer, in which polyols (polyhydroxyl alcohols) react with highly reactive diisocyanates. As a thermoset (they do not have a melting point), PU is difficult to recycle, and the current state-of-the-art mechanical recycling results in low-value materials. Nonetheless, chemolysis (chemical depolymerization) has been explored since decades as an alternative, yet was only commercially developed for polyol recovery. The absence of a working technology for recovery of diisocyanate derivatives is largely due to the complexity of these molecules, and a lack of knowledge regarding their chemical fate in a chemolysis process. The proposed STIMPRO aims at understanding how various isocyanate derivatives are formed, and how they react upon alcoholysis, by experiments using model monomers. This knowledge, together with experimental and computational insights in mixing/solubility, will be exploited to create a bottom-up chemolysis process for model polyurethanes. The outcome of the proposed study will be used in subsequent chemolysis of realistic waste polyurethanes, with recovery of both monomers as significant technological novelty. Additionally, the resulting knowledge may be transferred in the future formulation of new polyurethanes with biobased alternative monomers

Researcher(s)

• Promoter: Pazdur Lukasz
• Co-promoter: Billen Pieter
• Co-promoter: Vande Velde Christophe

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)
• Biochemical Wastewater Valorization & Engineering (BioWaVE)

Project type(s)

• Research Project

Abstract

The P2PC project aspires to cope with the urgent issue of plastics waste management. The project targets the challenge of increasing plastic waste volumes and diversity on the one hand, as well as the establishment of circular material schemes instead of value destruction. The most important premise of P2PC is that by pyrolysis, plastic waste that is currently being burned or landfilled can be a source of diverse chemical building blocks, the so-called "precious chemicals". Its target, in other words, is to turn plastic waste into value. This way, P2PC can be considered as the next step in Flanders' efforts to lead the global effort in tackling the challenge of waste plastics.

Researcher(s)

• Promoter: Billen Pieter
• Promoter: Tavernier Serge
• Co-promoter: Billen Pieter
• Co-promoter: Van Passel Steven

Research team(s)

• Biochemical Wastewater Valorization & Engineering (BioWaVE)
• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)

Project website

Project type(s)

• Research Project

Abstract

This proposal aims at demonstrating the suitability and elucidating the effect of new green solvent media, natural deep eutectic solvents (NADES), on enzymatic reactions. NADES are eutectic mixtures of two or more biological primary metabolites (saccharides, amino and other organic acids, polyols, urea, choline) that are liquid at or slightly above room temperature, due to networking hydrogen bond interactions. Although they have been investigated earlier as green extraction media, reports on their use for enzymatic reactions are limited. For the first time, we will investigate their influence on enzymatic reactions by disaggregating the following effects: solvation energy, mass transfer in bulk and enzyme-substrate-intermediates stability. A well-known enzymatic conversion, i.e. deacetylation of a crude mannosylerythritol lipid (MEL) mixture aided by Novozym 435 (a commercial lipase), will be performed in selected NADES as a case example. Although no multi-parametric regression modeling will be done, qualitative (and semi-quantitative) insights will be gathered through coupling parametric solubility modeling (Hansen model, with experimental validation and input) with physicochemical characterization (viscosity, surface tension) of NADES systems, and concentration (substrate, enzyme) and temperature dependent kinetic experiments and modeling. The anticipated outcome of the project is a clear indication of enzymatic performance in fit for purpose NADES, and a breakdown of marginal efficiency change into solvation, activity and mass transfer differences with respect to traditional organic solvent systems.

Researcher(s)

• Promoter: Billen Pieter
• Co-promoter: Cornet Iris

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)
• Biochemical Wastewater Valorization & Engineering (BioWaVE)

Project type(s)

• Research Project

Abstract

The MATTER-project, a two-year Catalisti-ICON project (2018-2019), wants to evaluate the recycling of mixed (post-consumer) plastic waste streams and to use the generated data to develop a decision supporting framework. Within the MATTER-project, technical and market-based criteria will be developed to support an optimal plastic waste management system. More specifically, the project will focus on the P+ fraction (all plastics packaging waste) of the extended P+MD collection and recycling scheme. Partners from across the whole value chain are included in the project consortium: separation and pretreatment (Indaver and Bulk.ID), mechanical recycling (Borealis and ECO-oh!) and thermochemical recycling (Indaver and Borealis). Sustainability analyses will enable the development of a decision-supporting framework.

Researcher(s)

• Promoter: Billen Pieter
• Co-promoter: Van Passel Steven

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)
• Biochemical Wastewater Valorization & Engineering (BioWaVE)

Project type(s)

• Research Project

Abstract

The ImPrOVE (Innovative (pre)POmace Valorization procEss) project addresses a major European wide agro-related problem: pomace resulting from pressing fruit. This high amount of pomace is considered waste, but contains natural and highly functional compounds. Skin and core of fruit contain protecting and functional molecules: antioxidants, stabilizers, colorants, aromas, fibers with potential in high value applications in cosmetics, diets and, as bio-additives in food and beverages. ImPrOVE aims to fully valorize pomace by using a combination of existing and innovative processes. These should be easy without high energy/cost demands, resulting in access for S(M)E's (economic strategic European targets) with profit redistributed over the whole chain, strengthening Europe's agro and food activities. ImPrOVE will design a generic process flow applicable to most pomace types. Two cases will be studied: Southern European olive pomace and Mid/Northern European apple/pear/cherry/cucumber pomace. Total valorization is achieved in three process clusters: (1) pretreatment of the pomace giving raise to aromas and oil from separated seeds; (2) extraction of high value materials from the pretreated pomace and (3) valorization of the resulting fibrous mass, either directly (functionally designed fibers) or by splitting cellulose-lignin and valorizing both materials physically, enzymatically and/or chemically. An ambitious concept is to use bio-based ionic liquids (BIOILs) or natural deep eutectic solvents (NADES) as extraction liquids advanced green solvents. More ambitious, highly appealing, is to study whether the extraction solution itself can be utilized instead of the isolated and purified ingredients, avoiding some downstream processing. Dermatological and metabolomic tests, (eco)toxicity, biodegradation, LCA, industrial relevance, scalability and economic viability will be sustainably addressed by the European multidisciplinary partner cluster, with academic and industrial members.

Researcher(s)

• Promoter: Billen Pieter
• Promoter: Tavernier Serge

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)
• Biochemical Wastewater Valorization & Engineering (BioWaVE)

Project type(s)

• Research Project

Abstract

This project aims to develop so-called "nanoreactors", which can be seen as an approach to heterogenization of homogeneous catalysis. The key idea is to develop self-assembling large-pore Metal Organic Frameworks (MOFs) via modification/optimization of their organic linkers. Starting from already existing networks, the organic linkers will be further functionalized at the side chains in order to couple them with a catalyst. The catalytic activity of the resulting nanoreactors will be demonstrated and their performance compared with the native catalyst in a homogeneous reaction mixture. As the reactors are crystalline, they have very well-defined pore shapes and sizes, the pores are continuous throughout the structure, and very controllable, reproducible and characterizeable. The project bridges the spearheads of "Materials Characterization" and "Sustainable Development".

Researcher(s)

• Promoter: Vande Velde Christophe
• Co-promoter: Cool Pegie
• Fellow: Fucci Rosa

Research team(s)

• Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS)
• Applied Electrochemistry & Catalysis (ELCAT)

Project type(s)

• Research Project