The catalytic conversion of oleic acid to aromatics (benzene, toluene, and xylenes, BTX) over a granular H-ZSM-5/Al2O3 catalyst (ϕ 1.2–1.8 mm, 10 g loading) was investigated in a continuous bench-scale fixed-bed reactor (10 g oleic acid h–1). A peak carbon yield of aromatics of 27.4% was obtained at a catalyst bed temperature of 550 °C and atmospheric pressure. BTX was the major aromatics formed (peak carbon yield was 22.7%), and a total BTX production of 1000 mg g–1 catalyst was achieved within a catalyst lifetime of 6.5 h for the fresh catalyst. The catalyst was deactivated due to severe coke deposition (ca. 22.1 wt % on the catalyst). The used catalyst was reactivated by an ex situ oxidative regeneration at 680 °C in air for 12 h. The regenerated catalyst was subsequently recycled, and in total, 7 cycles of reaction-regeneration were performed. A gradual decrease in the peak carbon yield of BTX was observed with reaction-regeneration cycles (e.g., to 16.3% for the catalyst regenerated for 6 times). However, the catalyst lifetime was remarkably prolonged (e.g., >24 h), leading to a significantly enhanced total BTX production (e.g., 3000 mg g–1 catalyst in 24 h). The fresh, used, and regenerated catalysts were characterized by N2 and Ar physisorption, XRD, HR-TEM-EDX, 27Al, and 29Si MAS ssNMR, NH3-TPD, TGA, and CHN elemental analysis. Negligible changes in textural properties, crystalline structure, and framework occurred after one reaction-regeneration cycle, except for a slight decrease in acidity. However, dealumination of the H-ZSM-5 framework was observed after 7 cycles of reaction-regeneration, leading to a decrease in microporosity, crystallinity, and acidity. Apparently, these changes are not detrimental for catalyst activity, and actually, the lifetime of the catalyst increases, rationalized by considering that coke formation rates are retarded when the acidity is reduced.
Using stable isotope techniques, this study shows that plasma free fatty acid oxidation is not impaired during exercise in non-obese type II diabetic patients.
Glycerol is an attractive bio-based platform chemical that can be converted to a variety of bio-based chemicals. We here report a catalytic co-conversion strategy where glycerol in combination with a second (bio-)feed (fatty acids, alcohols, alkanes) is used for the production of bio-based aromatics (BTX). Experiments were performed in a fixed bed reactor (10 g catalyst loading and WHSV of (co-)feed of 1 h-1) at 550 °C using a technical H-ZSM-5/Al2O3 catalyst. Synergistic effects of the co-feeding on the peak BTX carbon yield, product selectivity, total BTX productivity, catalyst life-time, and catalyst regenerability were observed and quantified. Best results were obtained for the co-conversion of glycerol and oleic acid (45/55 wt%), showing a peak BTX carbon yield of 26.7 C%. The distribution of C and H of the individual co-feeds in the BTX product was investigated using an integrated fast pyrolysis-GC-Orbitrap MS unit, showing that the aromatics are formed from both glycerol and the co-feed. The results of this study may be used to develop optimized co-feeding strategies for BTX formation. This journal is
In the last decade, the concept on interactions between humans, animals and their environment has drastically changed, endorsed by the One Health approach that recognizes that health of humans and animals are inextricably linked. Consideration of welfare of livestock has increased accordingly and with it, attention into the possibilities to improve livestock health via natural, more balanced nutrition is expanding. Central to effects of healthy nutrition is an optimal gastrointestinal condition which entails a well-balanced functional local immune system leading to a resilient state of well-being. This project proposal, GITools, aims to establish a toolbox of in vitro assays to screen new feed ingredients for beneficial effects on gastrointestinal health and animal well-being. GITools will focus on pig and chicken as important livestock species present in high quantities and living in close proximity to humans. GITools builds on intestinal models (intestinal cell lines and stem cell-derived organoids), biomarker analysis, and in vitro enzymatic and microbial digestion models of feed constituents. The concept of GITools originated from various individual contacts and projects with industry partners that produce animal feed (additives) or veterinary medicines. Within these companies, an urgent need exists for straightforward, well-characterized and standardized in vitro methods that provide results translatable to the in vivo situation. This to replace testing of new feed concepts in live animal. We will examine in vitro methods for their applicability with feed ingredients selected based on the availability of data from (previous) in vivo studies. These model compounds will include long and short chain fatty acids, oligosaccharides and herbal-derived components. GITools will deliver insights on the role of intestinal processes (e.g. dietary hormone production, growth of epithelial cells, barrier function and innate immune responses) in health and well-being of livestock animals and improve the efficiency of testing new feed products.
