Catalytic co-conversion of glycerol and oleic acid to bio-aromatics: Catalyst deactivation studies for a technical H-ZSM-5/Al2O3 catalyst

Enhanced Bio-BTX Formation by Catalytic Pyrolysis of Glycerol with In Situ Produced Toluene as the Cofeed

“…Catalytic pyrolysis of individual feed (namely, glycerol and toluene, both analytical grade) and copyrolysis of cofeeds (namely, glycerol/toluene, 93/7 wt %) were performed on a fixed bed reactor (with two feeding lines and optimized in previous work) , using 10 g of a technical H-ZSM-5/Al 2 O 3 (60/40 wt %) catalyst (optimized in previous work) , for a time on stream (TOS) of 12 h. Other reaction parameters are reaction temperature of 550 °C, atmospheric pressure, weight hourly space-velocity (WHSV) of the (co)feeds of 1 h –1 , and N 2 flow of 50 mL min –1 . These parameters were optimized in previous work and have been used to study catalytic copyrolysis of glycerol with cofeeds (such as fatty acids, alcohols, and alkanes). , Extended experimental procedures and product analysis are included in the Supporting Information.…”

“…Alternatively, increasing the hydrogen-to-carbon effective ratio (H/C eff ) of the feed by cofeeding glycerol (of which the H/C eff is 0.67) with various cofeeds with a higher H/C eff such as alcohols, , alkanes, , and free fatty acids, , has also been explored. Synergistic effects of the cofeeds on peak BTX carbon yield, BTX productivity (per cycle of reaction-regeneration), catalyst lifetime, and catalyst regenerability have been observed, and a cofeeding strategy has been proposed. , Of particular interest is the observation that polycyclic aliphatics (PCAs) may also be used as the cofeed . These PCAs can be obtained from the partial hydrogenation of polycyclic aromatic hydrocarbons (PAHs), , which are coproduced during catalytic pyrolysis of glycerol to BTX .…”

“…Alternatively, increasing the hydrogen-to-carbon effective ratio (H/C eff ) of the feed by cofeeding glycerol (of which the H/C eff is 0.67) with various cofeeds with a higher H/C eff such as alcohols, 35 , 36 alkanes, 36 , 37 and free fatty acids, 36 , 38 has also been explored. Synergistic effects of the cofeeds on peak BTX carbon yield, BTX productivity (per cycle of reaction-regeneration), catalyst lifetime, and catalyst regenerability have been observed, and a cofeeding strategy has been proposed.…”

“…Synergistic effects of the cofeeds on peak BTX carbon yield, BTX productivity (per cycle of reaction-regeneration), catalyst lifetime, and catalyst regenerability have been observed, and a cofeeding strategy has been proposed. 36 , 38 Of particular interest is the observation that polycyclic aliphatics (PCAs) may also be used as the cofeed. 39 These PCAs can be obtained from the partial hydrogenation of polycyclic aromatic hydrocarbons (PAHs), 24 , 39 which are coproduced during catalytic pyrolysis of glycerol to BTX.…”

Renewable p-Xylene Production by Catalytic Conversion of Crude Bioglycerol (GTA-pX Process)

“…Here, the main reaction is the dehydrocyclization of paraffin . However, the processing of oxygen-containing bioderived feeds needs an additional step of dehydration or deoxygenation and hence demands special features of the catalysts to achieve sustainable activity for the effective production of aromatics even in the presence of water and other reaction environments. − ZSM-5 is successfully employed for the methanol-to-aromatics (MTA) reaction due to its suitable acidity, three-dimensional (3D) pore structure, hydrophobicity (siliceous zeolite), high thermal stability, and higher aromatization activity . The situation is not similar for crude glycerol as it has a low effective H/C ratio (0.67) and high density ( d = 1.26 g cm –3 ), which not only affects its conversion but also leads to fast catalyst deactivation by coke formation. , These features limited the glycerol-to-aromatics (GTA) process, and therefore, the aromatic yield (<35C%) and p -X selectivity (<25%) achieved so far on ZSM-5-based catalysts are not satisfactory.…”