Karolien Vanbroekhoven

Flemish Institute for Technological Research | VITO

This review comprehensively explores various homogeneous and heterogeneous catalytic systems for the hydrogenolysis of oxygenated polymeric wastes (OXPs), presenting an adaptable solution to plastic pollution and generating valuable feedstock.

Poly(bisphenol A carbonate) (PC) is an essential polymer from fossil sources. Currently, PC lacks any economically viable recycling strategy, which leads to a loss of valuable resources, and the accumulation of PC in the environment can have a negative impact on human health due to the leaching of toxic Bisphenol A (BPA). BPA recovery from PC waste...

In 2018 a pan-European network CA17128 LignoCOST was established to build a strong platform to stimulate the development of lignin applications and exchange information between whole value chain actors. LignoCOST successfully brought together different experts to discuss and find solutions for the challenges using lignin in 7 priority applications....

This article reports a new family of functional side-chain phenolic polymers derived from lignin monomers, displaying a combination of properties that are usually mutually exclusive within a single material. This includes a well-defined molecular structure, transparency, antioxidant activity, and antistatic properties. Our design strategy is based...

Lignin is an abundant and renewable source of phenolic compounds that can be used as natural antioxidants to substitute synthetic, petroleum-based alternatives. The development of lignin depolymerization techniques has improved the accessibility of low-molecular-weight phenolic fractions with enhanced antioxidant activity compared to native lignin....

Lately, the interest in lignin valorization has notably grown within the scientific community. In the last decade, the number of publications focusing on lignin as an alternative to fossil-based resources has exponentially increased. Different strategies have been employed to valorize lignin as a source of renewable fuel and building blocks for che...

Lignin is a promising biopolymer to serve as a sustainable resource for a multitude of applications (e.g., thermoset materials, production of bulk chemicals) thereby substituting fossil-based carbon sources. In this work, the reductive depolymerization of Kraft lignin (KL) was studied in ethanol/water aided by formic acid (FA) as the way forward to...

Lignin, a by-product of the pulp and paper industry, that is traditionally extracted from wood in order to produce cellulose, is the most abundant natural source of aromatics on Earth. As such, it shows potential in polymer design, in which currently, the majority of the used resources are still fossil-based. Not only can lignin replace existing ha...

This short critical review gives an insight on the potential that lignin and its bio-oils present towards the production of thermosetting epoxy polymers and composites. Green and sustainable ways of producing monomers and polymers from renewable sources are critical and lignin, as an underutilized bio-based waste material, presents a high exploitat...

The use of lignin as a functional additive has long been a promising topic in both industry and academia, but the development of such systems is still limited by the considerable challenges posed by the incompatibility of lignin with common polymers. Herein, we designed modified silicone (MS) sealants with enhanced UV and thermal stability by incor...

Lignin is the second most abundant natural polymer that exhibits a complex structure with various amounts of aliphatic and phenolic hydroxides. The use of lignin as a source of polyol to make lignin-based polyurethanes (PUs) has been the subject of intense studies in recent years. It is well known that there is a difference in reactivity between al...

The synthesis of novel, renewable lignin‐based protective films with anticorrosive properties is presented in this work. Thermosetting films are prepared by means of tandem UV‐initiated thiol‐yne “click” synthesis and Claisen rearrangement strategy. These films contain high lignin loading, 46–61%, originating from a birch wood reductive catalytic f...

Over the past decade, advances in lignin characterization methods have led to a better understanding of lignin structure and reactivity. Novel chromatographic and spectrometric techniques, especially NMR, are now essential and routine for lignin analysis. Among these methods, quantitative ³¹P NMR spectroscopy proved itself as a powerful technique f...

The present invention relates to stabilizing monomers obtained from mono(meth)acrylated monolignols providing AA (antioxidant activity) to copolymers, and obtained copolymers thereof. It further provides methods for preparing such copolymers, the building blocks and the use thereof in the manufacture of copolymers comprising said stabilizing monome...

The present invention discloses a membrane-less reactor design for microbial electrosynthesis of alcohols from carbon dioxide (CO2). The membrane-less reactor design thus facilitates higher and efficient CO2 transformation to alcohols via single pot microbial electrosynthesis. The reactor design operates efficiently avoiding oxygen contact at worki...

The utilization of biorefinery lignins as a renewable resource for the production of bio-based chemicals and materials remain a challenge because of the high polysaccharide content of this variety of lignins. This study provides two simple methods; (i) the alkaline hydrolysis-acid precipitation method and (ii) the acid hydrolysis method for the rem...

Glucose‐ and xylose laurate esters were enzymatically synthesized using equimolar substrate concentrations in 2‐methyl‐2‐butanol, comparing free lauric acid with methyl‐ and vinyl laurate as acyl donors. All reactions resulted in ≥ 70% acyl donor conversions after 72 h but the activated donors were also partially hydrolyzed to lauric acid, highligh...

Thanks to chemical stabilization, Aldehyde-Assisted Fractionation (AAF) of lignocellulosic biomass has recently emerged as a powerful tool for the production of largely uncondensed lignin. Depolymerization of AAF lignin via ether cleavage provides aromatic monomers at near theoretical yields based on ether cleavage as well as an oligomeric fraction...

The current climate awareness coupled with increased focus on renewable energy and biobased chemicals have led to an increased demand for such biomass derived products. Electrosynthesis is a relatively new approach that allows a shift from conventional fossil-based chemistry towards a new model of a real sustainable chemistry that allows to use the...

The widespread utilization of plastics results in millions of tons of waste plastics being generated every year. During the last decade, converting waste plastics to valuable resources has been a primary objective for researchers in academia and industry. Nonetheless, most of the plastic recycling methods still rely on mechanical processes that are...

An enrichment methodology was developed for a homoacetogenic biocathode that is able to function at high concentrations of bicarbonates for the microbial electrosynthesis (MES) of acetate from carbon dioxide. The study was performed in two stages; enrichment of consortia in serum bottles and the development of a biocathode in MES. A homoacetogenic...

Lignin is the most abundant source of renewable ready-made aromatic chemicals for making sustainable polymers. However, the structural heterogeneity, high polydispersity, limited chemical functionality and solubility of most technical lignins makes them challenging to use in developing new bio-based polymers. Recently, greater focus has been given...

Lignin is a renewable and abundant source for production of bio-based chemicals and is a valuable alternative to crude oil to obtain aromatic building blocks. It is built from aromatic units with strong chemical linkages, which need to be cleaved to enable the use of the aromatic compounds in industrial applications. In addition to depolymerizing l...

The current chemical industry has been heavily optimised for the use of petroleum-derived base chemicals as its primary source of building-blocks. However, incorporation of heteroatoms, absent in the base chemicals, is necessary to meet the different property requirements in the plethora of products the industry makes such as plastics, cosmetics an...

The present invention relates to a carbon based electrode with a large geometrical surface area comprising a frame of an electrically conductive material with several cut-outs with a surface area, which cut-outs are separated from each other by portions of the conductive material, wherein carbon based sub-electrodes dimensioned so as to a least cov...

This paper gives detailed insight in the solventless synthesis of (meth)acrylate esters catalysed by Novozym 435 with a focus on the quantitative understanding of the reaction kinetics. The (meth)acrylate esters were formed from various (heavy boiling) alcohols by applying methyl (meth)acrylate in excess. Attractive ester titers were obtained (up t...

Carbon dioxide (CO2) valorization for the production of different commodity chemicals is a highly desired approach to moderate CO2 emissions into the atmosphere. The versatility of microbial electrochemical technologies makes it possible to use them for carbon capture and utilization. This is mainly achieved through two novel processes, namely: mic...

Lignin is the most abundant source of renewable ready-made aromatic chemicals for making sustainable polymers. However, the structural heterogeneity, high polydispersity, limited chemical functionality and solubility of most technical lignins makes them challenging to use in developing new bio-based polymers. Recently, greater focus has been given...

Reduction of carbon dioxide (CO2) released from the industries helps to reduce the greenhouse gases (GHGs) emissions to the atmosphere while producing value added chemicals and contributes to carbon fixation. Microbial electrosynthesis (MES) is a recent process which accomplishes this idea by using cathodic bacteria at the expense of minimum energy...

Impact of gas diffusion electrodes (GDEs) was evaluated in enhancing the CO2 bio-availability for its transformation to C4-organics, especially to alcohols using selective mixed culture. Observed current density was more stable (9-11 A/m2) than submerged experiments reported and significantly varied with pH and respective CO2 solubility. Uncontroll...

A recent concept of microbial electrosynthesis (MES) has evolved as the electricity-driven production of chemicals from low-value waste using microbes as catalysts. MES from carbon dioxide (CO2) comprises bioelectrochemical reduction of CO2 to multi-carbon organic compounds using the reducing equivalents produced at the electrically-polarized catho...

The recent concept of microbial electrosynthesis (MES) has evolved as an electricity-driven production technology of chemicals from low-value carbon dioxide (CO2) using micro-organisms as biocatalysts. MES from CO2 comprises bioelectrochemical reduction of CO2 to multi-carbon organic compounds using the reducing equivalents produced at the electric...

Bioelectrochemical reduction of carbon dioxide (CO2) to multi-carbon organic compounds particularly acetate has been achieved in microbial electrosynthesis (MES) using the reducing equivalents produced at the electrically polarized cathode. MES based on CO2 reduction produced 7–10 g L⁻¹ acetate at the cathode while operating the CO2 fed reactor in...

Enzymatic electrosynthesis of formic acid from carbon dioxide (CO2) reduction using formate dehydrogenase (FDH) as catalyst at cathode both in its free and immobilized forms was studied in detail in bioelectrochemical system (BES). The essential role of solubilizing CO2 for its conversion was also studied by adding carbonic anhydrase (CA) to the FD...

Application of enzymes as biocatalysts is highly favored due to their excellent substrate specificity and stereoselectivity as well as their effectiveness to work under mild conditions with low environmental burden. Enzymes are widely applied in the bioindustrial manufacture of bulk and fine chemicals which eventually find application in various ar...

Microbial catalysis of carbon dioxide (CO2) reduction to multi-carbon compounds at the cathode is a highly attractive application of microbial electrosynthesis (MES). The microbes reduce CO2 by either taking the electrons or reducing the equivalents produced at the cathode. While using gaseous CO2 as the carbon source, the biological reduction proc...

No abstract is available for this article.

No abstract is available for this article.

No abstract is available for this article.

In microbial electrosynthesis (MES), CO2 can be reduced preferably to multi-carbon chemicals by a biocathode-based process which uses electrochemically active bacteria as catalysts. A mixed anaerobic consortium from biological origin typically produces methane from CO2 reduction which circumvents production of multi-carbon compounds. This study aim...

One of the most intriguing renewable energy production methods being explored currently is electrical power generation by microbial fuel cells (MFCs). However, to make MFC technology economically feasible, cost efficient electrode manufacturing processes need to be proposed and demonstrated. In this context, VITO has developed an innovative electro...

Microbial Fuel Cells (MFCs), the bioelectrochemical devices for conversion of waste into electricity through bacterial metabolic activity can use substrates with different complexity and strength. Wastewaters with moderate to high organic content can be exploited as MFC substrates. In this study, four different industrial wastewaters (from a chemic...

Electro-fermentation (EF) merges traditional industrial fermentation with electrochemistry. An imposed electrical field influences the fermentation environment and microbial metabolism in either a reductive or oxidative manner. The benefit of this approach is to produce target biochemicals with improved selectivity, increase carbon efficiency, limi...

Microbial Electrosynthesis (MES) comprises electro-reduction of carbon dioxide (CO2) to multi-carbon organic compounds by chemolithotrophs using electrons from a cathode. Reduction of CO2 to chemicals through microbial electrocatalysis was investigated by using a mixed culture of acetogenic and carboxydotrophic bacteria forming a microbial biofilm...

Microbial Electrosynthesis (MES) comprises electro-reduction of carbon dioxide (CO 2 ) to multi-carbon organic compounds by chemolithotrophs using electrons from a cathode. Reduction of CO 2 to chemicals through microbial electrocatalysis was investigated by using a mixed culture of acetogenic and carboxydotrophic bacteria forming a microbial biofi...

Industrial revolution, a consequence of the rapid economic growth, has contributed to ever increasing demand for energy and has resulted in about 40% rise in the atmospheric concentration of carbon dioxide, from 280 ppm in 1750 to 400 ppm in 2015. Abundant use of fossil fuels has become a cause of concern due to their adverse effects on the environ...

Among the various renewable energy sources, biohydrogen is gaining a lot of traction as it has very high efficiency of conversion to usable power with less pollutant generation. The various technologies available for the production of biohydrogen from lignocellulosic biomass such as direct biophotolysis, indirect biophotolysis, photo, and dark ferm...

As opposed to common practices such as composting, landfilling and incineration, advanced food waste (FW) valorization strategies are more appealing from the practical, economic and sustainability viewpoints as these can generate multiple products from a single feedstock by taking a biorefinery approach. This chapter focuses on a cascade-type valor...

In the direction of generating value added chemicals from CO2 reduction through microbial electrosynthesis, considering the crucial impact of electrode material for the biofilm development and electron delivery, an attempt was made in this study to evaluate the efficiency of two different materials as biocathodes and their respective output in term...

Microbial fuel cells (MFCs) which are operated in continuous mode are more suitable for practical applications than fed batch ones. The aim of the present study was to characterize an air-cathode MFC operating in continuous mode and to determine the intrinsic properties for suitable performance and scalability. Air-cathode MFCs were constructed fro...

Biovalorization of dark fermentation effluent (DFE) in a microbial fuel cell (MFC) was studied using the biocatalyst enriched from farm manure. The MFC performance was evaluated in terms of power density, substrate degradation, energy conversion efficiency and shifts in system redox state with operation time and organic loading rate (OLR). Higher p...

Bioelectrochemical system (BES) was operated using the enzyme formate dehydrogenase as catalyst at cathode in its free form for the reduction of CO2 into formic acid. Electrosynthesis of formic acid was higher at an operational voltage of -1V vs. Ag/AgCl (9.37mgL(-1) CO2) compared to operation at -0.8V (4.73mgL(-1) CO2) which was strongly supported...

Recent interest in the field of biocommodities production through bioelectrochemical systems has generated interest in the enzyme catalyzed redox reactions. Enzyme catalyzed electrodes are well established as sensors and power generators. However, a paradigm shift in recent science towards the production of useful chemicals has changed the face of...

In this study, domestic wastewater was given a second life as dilution medium for concentrated organic waste streams, in particular artificial food waste. A two-step continuous process with first volatile fatty acid (VFA)/hydrogen production and second electricity production in microbial fuel cells (MFCs) was employed. For primary treatment, biorea...

Sulfate-reducing bacteria (SRB) developed biocathodes efficient for reduction of acetic and butyric acids to alcohols and acetone via direct electron transfer reaching current densities of 160-210 A m(-2).

Microcosms containing sediment from an aquifer in Cambodia with naturally elevated levels of arsenic (As) in the associated groundwater were used to evaluate the effectiveness of microbially-mediated production of iron minerals for in situ As remediation. The microcosms were first incubated without amendments for 28 days and the release of As and o...