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.
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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
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The Andean lupin (Lupinus mutabilis) is one of the lost crops of Incas and has been grown in South America and as a food crop for thousands of years. The seeds are the main source of commercial value regarding the high content of oil (about 20%), protein (about 43%) and carbohydrates (about 33%). A European Union H2020 project, LIBBIO, aims to develop and optimize the breeding and cropping of the Andean lupin in the Europe, and to process the lupin seeds for new and high-value products for consumers and for incorporation into otherproducts. This study works at optimizing the oil extraction from the lupin seeds using supercritical carbon dioxide (scCO2), which has been tested for lupin oil extraction and is advantageous over organic extractants due to the mild operating temperature, costeffectiveness, nontoxicity, and easy post-separation.In the study designed by response surface methodology, the operating pressure,temperature, scCO2 flowrate, and sample mesh size, were investigated on their effect on the oil extraction efficiency. The pressure, scCO2 flowrate and mesh size were found to affect the extraction efficiency significantly. The higher the pressure and the smaller the mesh, the more oil was extracted over a specific period. Optimally about 85% of the oil was extracted by scCO2 compared with conventional Soxhlet extraction using hexane as the extractant. Oleicacid (46%) and Linoleic acid (32%) are the two main fatty acids in the extracted oil. About 80% of the fatty acids are unsaturated. The stearic acid is one of the main saturated fatty acids, which has relatively positive effects on human health to others. The pressure was found to significantly affect the fractions of the saturated and unsaturated fatty acids. The content of tocopherols in the extracted oil ranged from 1 to 20 mg/100g oil, which is comparable withliterature value.
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