Luc Alaerts

• KU Leuven

Product passports (PPs) are the newest instance of transaction systems that try to mitigate the information gaps between stakeholders and foster the Circular Economy (CE). Regulators progressively prescribe its implementation and use. However, the contributions of PP systems to the CE are not self-evident, as some systems fail to deliver added valu...

The circular economy (CE) is a vital sustainability concept that requires well-designed information systems (IS). However, the IS scholars' understanding of the CE is emerging, and its problems are fragmented and not fully understood yet. This work presents a qualitative study of 20 organizations to explore future research on digital CE. The result...

Increasing the use intensity of individual garments is crucial in reducing the total environmental impact of clothing consumption. Implementing circular economy strategies, such as reuse, can intensify the use of garments. However, a deeper understanding of the current fulfilment of the need for clothing is essential for the effective implementatio...

In the coming decade, the EU intends to intervene in the textile value chain to steer it towards sustainability and circularity. As part of this effort, post-consumer textile (PCT) management should align with the waste hierarchy. This study employs material flow analysis (MFA) to examine and compare PCT management in two European regions: Flanders...

This paper identifies and validates the challenges hindering the integration of circular economy into evidence-based policy making, and proposes an outlook for enhancing the effective use of circular economy monitors. It highlights the limitations of current circular economy monitoring systems, which often fail to transform circular economy informa...

With the circular economy transition increasingly becoming a political goal, the ability to monitor progress has become key. Over the past few years, monitoring instruments have appeared at the levels of countries and regions. While their effectiveness still has to be proven, a common gap seems to be that they nowhere seem to have been approached e...

Information gaps are one of the significant barriers to a flourishing circular economy (CE). Information systems (IS) are implemented to overcome these gaps as part of digitalization efforts. In the CE context, IS can provide insights into the sustainability and circularity of a product and its value chain. In fact, many products come into existenc...

Information gaps are one of the major obstacles identified for the realization of a circular economy. Therefore, so-called product passports (PPs) are presented as a solution in the literature. A PP should provide the necessary information to all stakeholders along the product’s value chain to act more circularly. In general, information systems (I...

Information gaps significantly hinder the circular economy (CE). Smart information systems (IS) will play a central role in implementing the CE and the shift toward it. Therefore, implementers of future IS architectures and researchers developing new IS designs must know how CE objectives can be included in the system requirements. Requirements are...

Information gaps are one of the major obstacles identified for the realization of a circular economy. Therefore, so-called product passports (PPs) are presented as a solution in the literature. A PP should provide the necessary information to all stakeholders along the product’s value chain to act more circularly. In general, information systems (I...

To date, the methods of compiling policy monitors for the circular economy (CE) often focus on recycling heavily and neglect higher circular strategies and environmental and social impacts. With 17 stakeholders from different domains meeting in several workshops, we developed a holistic method to compile indicators for policymakers steering the CE...

To date, the methods of compiling policy monitors for the circular economy (CE) often focus on recycling heavily and neglect higher circular strategies and environmental and social impacts. With 17 stakeholders from different domains meeting in several workshops, we developed a holistic method to compile indicators for policymakers steering the CE...

The post-consumer plastic packaging waste management in Flanders was analyzed by performing a retrospective material flow analysis, covering an extensive period from 1985 to 2019. In addition, a prospective material flow analysis of 32 improvement scenarios was performed, based on expected changes in the waste management system. Mass recovery rates...

Within the food sector, the implementation of a circular economy (CE) can reduce resource consumption and emissions to the environment by moving away from a linear and unsustainable system. This necessitates a clear vision on what circularity for food means, which will provide a much-needed foundation to develop a monitoring tool that reveals insig...

Based on a survey of 2,106 individuals, this study aims to get a better understanding of the attitudes toward carsharing in Flanders, Belgium. Several drivers and barriers that influence household decisions to participate in a carsharing system are identified. An ordinal logit model reveals that highly educated, younger males with high ecological c...

In recent years, cities have revealed themselves as being prominent actors in the circular economy transition. Besides supporting and initiating urban projects catalyzing circularity, cities are looking for monitoring tools that can make their progress towards circularity visible. Adopting Leuven’s pilot project for a building materials bank as a c...

Circular Economy (CE) is a growing topic, especially in the European Union, that promotes the responsible and cyclical use of resources possibly contributing to sustainable development. CE is an umbrella concept incorporating different meanings. Despite the unclear concept, CE is turned into defined action plans supported by specific indicators. To...

The increasing focus on circular economy at the level of governments and policy requires the development of appropriate indicators to effectively monitor the progress towards the circular economy. Currently two very different types of indicator areas are under development: (i) monitoring frameworks based on macro indicators that summarize the progr...

Bio-based plastics are increasingly appearing in a range of consumption products, and after use they often end up in technical recycling chains. Bio-based plastics are different from fossil-based ones and could disturb the current recycling of plastics and hence inhibit the closure of plastic cycles, which is undesirable given the current focus on...

The effect of a post-synthetic acid treatment on the catalytic performance of MOFs is evaluated for MIL-100(Fe), an iron-benzenetricarboxylate. The acid-treated frameworks are structurally robust as no differences have been found in XRD patterns after treatment. Porosity of the acid-treated MOFs gradually decreases, most probably as a consequence o...

IntroductionMOFs with Catalytically Active Metal Nodes in the FrameworkCatalytic Functionalization of Organic Framework LinkersHomochiral MOFsMOF-Encapsulated Catalytically Active GuestsMesoporous MOFsConclusions References

Bring in the cleaner! Metal-organic frameworks (MOFs) are able to separate nitrogen and sulfur contaminants from fuel, which may lead to the production of cleaner fuels (see picture; ppmw=parts per million by weight). The separation ability is shown to originate from the Lewis acidity of the metal sites in the MOFs.

The water-stable metal-organic framework MIL-53(Cr) is able to adsorb phenol and p-cresol from contaminated water as well as the monomeric sugar D-(-)-fructose. Based on the isotherm for phenol uptake from the liquid phase, it is proposed that the framework breathes to maximize the uptake.

The metal-organic frameworks MIL-47 (V(IV)O{O(2)C-C(6)H(4)-CO(2)}) and MIL-53(Al) (Al(III)(OH)·{O(2)C-C(6)H(4)-CO(2)}) are capable of separating ethylbenzene and styrene. Both materials adsorb up to 20-24 wt % of both compounds. Despite the fact that they have identical building schemes, the reason for preferential adsorption of styrene compared to...

This work studies the liquid phase separation of styrene and ethylbenzene on the metal−organic framework [Cu3(BTC)2] (BTC = 1,3,5-benzenetricarboxylate) as well as the analogous separation of vinyltoluenes from ethyltoluenes. Batch and column experiments have been performed to demonstrate the capacity of the material to separate styrene and ethylbe...

Metal-organic framework materials (MOFs) are a class of microporous and crystalline materials with great potential for adsorption-based separations. Harnessing the separation ability of these materials in high-performance liquid chromatography (HPLC) requires the use of small and uniform particles in order to achieve good column packing. The well-k...

IntroductionPreparation and StructureApplicationsConclusion AcknowledgmentsAbbreviationsReferences

Processing metal organic frameworks with spatial and temporal control over crystal formation will increase the applicability of these highly porous materials. By exploiting solvent effects, stable synthesis solutions can be obtained, which can be used in combination with soft lithographic techniques to deposit oriented crystals in patterns by in si...

A new method based on patterned metallization and galvanic displacement is demonstrated to easily deposit patterned thin films of the metal-organic framework [Cu(3)(BTC)(2)].

This work studies the liquid-phase separation of the aliphatic C(5)-diolefins, mono-olefins, and paraffins, a typical feed produced by a steam cracker, with a focus on the seldomly studied separation of the C(5)-diolefin isomers isoprene, trans-piperylene, and cis-piperylene. Three adsorbents are compared: the metal-organic framework MIL-96, which...

The incorporation of metal-organic frameworks (MOFs) as fillers in polydimethylsiloxane (PDMS) membranes was investigated. Mixed matrix membranes (MMMs) with MOFs [Cu3(BTC)2], MIL-47, MIL-53(Al) and ZIF-8 as dispersed phases were synthesized and characterized. The membranes were applied in solvent resistant nanofiltration (SRNF), more in particular...

A study was conducted to demonstrate an electrochemical method for growing functional metal organic framework (MOF) coatings. The applied voltage served as a means to synthesize MOF crystals without the need to investigate their properties. The electrochemical synthesis of MOF coatings enabled a salt-free and continuous production in industrial env...

Vapour-phase adsorption and separation of the C8 alkyl aromatic compounds p-xylene, m-xylene, o-xylene, and ethylbenzene has been studied on the metal-organic framework MIL-53. Adsorption and desorption isotherms of the pure components at 110 degrees C were determined using the gravimetric technique. The adsorption isotherms show two well-defined s...

Three metal-organic frameworks (MOFs) with similar pore window diameters, [Cu(3)(BTC)(2)], MIL-47 and MIL-53(Al), are tested for adsorption of olefins, alkylnaphthalenes and dichlorobenzenes in the liquid phase. Selective adsorption of olefins is possible only on [Cu(3)(BTC)(2)] viapi-complexation on its open metal sites. This material shows a rema...

Adsorptive separation of CH4/CO2 mixtures was studied using a fixed-bed packed with MIL-53(Al) MOF pellets. Such pellets of MIL-53(Al) were produced using a polyvinyl alcohol binder. As revealed by N2 adsorption isotherms, the use of polyvinyl alcohol as binder results in a loss in overall capacity of 32%. Separations of binary mixtures in breakthr...

The metal−organic framework MIL-53(Al) was tested for selective adsorption and separation of xylenes and ethylbenzene, ethyltoluenes, and cymenes using batch, pulse chromatographic, and breakthrough experiments. In all conditions tested, MIL-53 has the largest affinity for the ortho-isomer among each group of alkylaromatic compounds. Separations of...

Vapor-phase adsorption and separation of the C8 alkylaromatic components p-xylene, m-xylene, o-xylene, and ethylbenzene on the metal-organic framework MIL-47 have been studied. Low coverage Henry adsorption constants and adsorption enthalpies were determined using the pulse chromatographic technique at temperatures between 230 and 290 degrees C. Th...

The capacity and selectivity of the metal-organic framework MIL-47 for liquid phase adsorption are shown to heavily depend on the pretreatment of the material, as illustrated in detail by the particular case of selective xylene adsorption. By totally removing the uncoordinated terephthalic acid from the pores and simultaneously avoiding oxidation t...

Reliable strategies are presented for the immobilization of molecular catalysts for selective oxidation in the liquid phase. Besides classical strategies such as ion exchange or covalent anchoring, new approaches are emerging, e.g. based on supported ionic-liquid phases or on incorporation of the active centre in a coordination polymer or a metal-o...

[Cu3(BTC)2] is a highly selective Lewis acid catalyst for isomerizations of terpene derivatives, such as the rearrangement of a-pinene oxide to campholenic aldehyde and the cyclization of citronellal to isopulegol. By using the ethylene ketal of 2-bromopropiophenone as a test substrate, the active sites in [Cu3(BTC)2] were proven to be hard Lewis a...

Low coverage adsorption properties of C2-C7 linear and C5-C7 iso-alkanes are measured. Shape selective properties of the Cu3(BTC)2 MOF are determined using the pulse chromatographic technique. Preferential adsorption of linear over methylbranched alkanes is observed. Linear alkanes fit better in the pores resulting in stronger interaction with the...

Ein Durchbruch: Das mikroporöse metall-organische Gerüst MIL-47 ist ein ausgezeichnetes Adsorbens für die Trennung von C8-Alkylarenen wie Ethylbenzol, meta-Xylol und para-Xylol. Das Anwendungspotenzial von MIL-47, mit seiner hohen Aufnahmekapazität und seiner Hydrophobie, wurde mit Durchbruch- und chromatographischen Experimenten nachgewiesen (sieh...

An optimized procedure was designed for the preparation of the microporous metal-organic framework (MOF) [Cu3(btc)2] (BTC=benzene-1,3,5-tricarboxylate). The crystalline material was characterized by X-ray diffraction, optical microscopy, SEM, X-ray photoelectron spectroscopy, N2 sorption, thermogravimetry, and IR spectroscopy of adsorbed CO. CO ads...

Metaal-organische netwerken (metal-organic frameworks, MOFs) zijn een nieuwe groep microporeuse en kristallijne materialen met bijzonder hoge porievolumes en een hoofdzakelijk organische poriebekleding. Momenteel ligt de nadruk in de literatuur nog sterk op de synthese van nieuwe materialen, terwijl de zoektocht naar toepassingen voor deze material...