A time- and space-resolved deactivation study on the conversion of glycerol to aromatics over H-ZSM-5 was performed. For this purpose, glycerol was vaporized/pyrolyzed in a pyrolysis section followed by a catalytic aromatization step. Benchmark performance showed an induction period of ca. 20 min, followed by a rather constant BTX yield of ca. 25.4 ± 2.2C.% for 3–4 h time on stream (TOS). Subsequently, a rapid drop in BTX yield was observed due to catalyst deactivation. Severe coking leads to coverage of catalyst surface area and blockage of micropores, particularly at the entrance of the catalyst bed at short TOS, indicating the presence of an axial coke gradient in the fixed bed reactor. At longer TOS, coke was formed throughout the bed and negligible BTX yield was shown to be associated with the presence of coke at all bed positions. Besides coking, the acidity of the catalyst was also reduced, and dealumination occurred, both with a similar time–space evolution. The results were explained by a conversion-zone migration model, which includes a deactivation zone (with severely coked catalyst), a conversion zone (BTX formation), and an induction zone (a.o. (de-)alkylation reactions), and describes the time- and space-resolved evolution of coking and relevant changes in other catalyst characteristics.
The catalytic coconversion of glycerol and toluene (93/7 wt %) over a technical H-ZSM-5/Al2O3 (60-40 wt %) catalyst was studied, aiming for enhanced production of biobased benzene, toluene, and xylenes (bio-BTX). When using glycerol/toluene cofeed with a mass ratio of 93/7 wt %, a peak BTX carbon yield of 29.7 ± 1.1 C.% (at time on stream (TOS) of 1.5-2.5 h), and an overall BTX carbon yield of 28.7 C.% (during TOS of 8.5 h) were obtained, which are considerably higher than those (19.1 ± 0.4 C.% and 11.0 C.%) for glycerol alone. Synergetic effects when cofeeding toluene on the peak and overall BTX carbon yields were observed and quantified, showing a relative increase of 3.1% and 30.0% for the peak and overall BTX carbon yield (based on the feedstock). These findings indicate that the strategy of cofeeding in situ produced toluene for the conversion of glycerol to aromatics has potential to increase BTX yields. In addition, BTX production on the catalyst (based on the fresh catalyst during the first run for TOS of 8.5 h and without regeneration) is significantly improved to 0.547 ton ton-1catalyst (excluding the 76% of toluene product that is 0.595 ton ton-1catalyst for the recycle in the cofeed) for glycerol/toluene cofeed, which was 0.426 ton ton-1catalyst for glycerol alone. In particular, this self-sufficient toluene product recycling strategy is advantageous for the production and selectivity (relative increase of 84.4% and 43.5% during TOS of 8.5 h) of biobased xylenes.
(Inter)nationaal is er discussie over de vraag of auditieve verwerkingsproblemen (AVP) gezien moeten worden als een unieke klinische diagnose en over de meest geschikte diagnostisering en verwijzing van kinderen in deze doelgroep. Binnen de Nederlandse Audiologische Centra (AC) wordt mede hierdoor verschillend omgegaan met kinderen met zogenaamde onverklaarde luisterproblemen.Het doel van het huidige document is om professionals handvatten te bieden bij het identificeren, diagnosticeren en behandelen van kinderen met luisterproblemen. Het ‘Dutch Position Statement Kinderen met Luisterproblemen’ is ontwikkeld op basis van het huidige wetenschappelijke bewijs omtrent luisterproblemen en op basis van bijeenkomsten gehouden met professionals. Over de volgende 9 statements is consensus bereikt onder professionals van de Nederlandse Audiologische Centra:Definitie:(1) De doelgroep ‘kinderen met luisterproblemen’ is geen unieke en aantoonbare klinische entiteit.(2) De problemen van kinderen met luisterproblemen zijn multimodaal.(3) De symptomen die kinderen met luisterproblemen vertonen kunnen ook voorkomen bij kinderen met andere ontwikkelingsstoornissen, zoals AD(H)D, TOS, dyslexie en leerstoornissen.Signalering en verwijzing:(4) Na signalering van luisterproblemen kan worden doorverwezen naar een multidisciplinair centrum.Diagnostiek:(5) Bij het diagnosticeren van een kind met luisterproblemen zijn minimaal een klinisch- fysicus audioloog, logopedist en gedragswetenschapper betrokken.(6) Luisterproblemen worden in eerste instantie in kaart gebracht met behulp van een anamnese (hulpvraag centraal) en indien beschikbaar een gevalideerde vragenlijst.(7) Bij kinderen met luisterproblemen wordt naast het toon- en spraakaudiogram altijd een spraak-in-ruis test afgenomen.(8) De diagnostische procedure bij luisterproblemen start vanuit een breed ontwikkelingsperspectief.Behandeling:(9) Bij kinderen met luisterproblemen is de interventie gericht op de hulpvraag en staat het handelingsgericht werken centraal.Dit document informeert professionals in Nederland, die te maken hebben met kinderen die worden aangemeld met klachten met betrekking tot het luisteren bij een goed perifeer gehoor over het huidige beschikbare bewijs en over het gezamenlijke standpunt hierover in Nederland.
Aaltjes: automatisch classificeren en tellen. Agrariërs laten bodemmonsters analyseren op onder meer aanwezigheid van aaltjes. Deze bodemanalyse is voor agrariërs cruciaal om de bodemgezondheid- en vruchtbaarheid vast te stellen maar behelst een grote kostenpost. Het identificeren, analyseren en tellen van aaltjes (nematoden) in een bodemmonster geschiedt in een gespecialiseerd laboratorium. Dit is tijdrovend, specialistisch en seizoensgebonden werk. Het tellen- en analyseren van aaltjes is mensenwerk en vergt training en ervaring van de laborant. Daarnaast hebben de laboratoria te maken met personeelstekort en de laboranten met sterk fluctuerende werkdruk. Derhalve is het speciaal voor dit project opgerichte samenwerkingsverband tussen Fontys GreenTechLab, ROBA Laboratorium en CytoSMART voornemens om een oplossing te ontwikkelen voor het automatisch classificeren en tellen van aaltjes. Dit project richt zich op de ontwikkeling van een proof of concept van een analysescanner. Het werk van de laboranten wordt grotendeels geautomatiseerd waarbij door de scanner de bodemmonsters middels toepassing van deep learning en virtual modeling kan worden geanalyseerd. Daarmee wordt beoogd een oplossing te bieden waarmee het personeelstekort wordt tegengegaan, de werkdruk kan worden verlaagd, mensenwerk wordt geautomatiseerd (waardoor de kans op fouten wordt verkleind) en de kosten voor agrariërs worden verlaagd.
Micro and macro algae are a rich source of lipids, proteins and carbohydrates, but also of secondary metabolites like phytosterols. Phytosterols have important health effects such as prevention of cardiovascular diseases. Global phytosterol market size was estimated at USD 709.7 million in 2019 and is expected to grow with a CAGR of 8.7% until 2027. Growing adoption of healthy lifestyle has bolstered demand for nutraceutical products. This is expected to be a major factor driving demand for phytosterols. Residues from algae are found in algae farming and processing, are found as beachings and are pruning residues from underwater Giant Kelp forests. Large amounts of brown seaweed beaches in the province of Zeeland and are discarded as waste. Pruning residues from Giant Kelp Forests harvests for the Namibian coast provide large amounts of biomass. ALGOL project considers all these biomass residues as raw material for added value creation. The ALGOL feasibility project will develop and evaluate green technologies for phytosterol extraction from algae biomass in a biocascading approach. Fucosterol is chosen because of its high added value, whereas lipids, protein and carbohydrates are lower in value and will hence be evaluated in follow-up projects. ALGOL will develop subcritical water, supercritical CO2 with modifiers and ethanol extraction technologies and compare these with conventional petroleum-based extractions and asses its technical, economic and environmental feasibility. Prototype nutraceutical/cosmeceutical products will be developed to demonstrate possible applications with fucosterol. A network of Dutch and African partners will supply micro and macro algae biomass, evaluate developed technologies and will prototype products with it, which are relevant to their own business interests. ALGOL project will create added value by taking a biocascading approach where first high-interest components are processed into high added value products as nutraceutical or cosmeceutical.
Micro and macro algae are a rich source of lipids, proteins and carbohydrates, but also of secondary metabolites like phytosterols. Phytosterols have important health effects such as prevention of cardiovascular diseases. Global phytosterol market size was estimated at USD 709.7 million in 2019 and is expected to grow with a CAGR of 8.7% until 2027. Growing adoption of healthy lifestyle has bolstered demand for nutraceutical products. This is expected to be a major factor driving demand for phytosterols.Residues from algae are found in algae farming and processing, are found as beachings and are pruning residues from underwater Giant Kelp forests. Large amounts of brown seaweed beaches in the province of Zeeland and are discarded as waste. Pruning residues from Giant Kelp Forests harvests for the Namibian coast provide large amounts of biomass. ALGOL project considers all these biomass residues as raw material for added value creation.The ALGOL feasibility project will develop and evaluate green technologies for phytosterol extraction from algae biomass in a biocascading approach. Fucosterol is chosen because of its high added value, whereas lipids, protein and carbohydrates are lower in value and will hence be evaluated in follow-up projects. ALGOL will develop subcritical water, supercritical CO2 with modifiers and ethanol extraction technologies and compare these with conventional petroleum-based extractions and asses its technical, economic and environmental feasibility. Prototype nutraceutical/cosmeceutical products will be developed to demonstrate possible applications with fucosterol.A network of Dutch and African partners will supply micro and macro algae biomass, evaluate developed technologies and will prototype products with it, which are relevant to their own business interests. ALGOL project will create added value by taking a biocascading approach where first high-interest components are processed into high added value products as nutraceutical or cosmeceutical.
