Effect of the Isopropanol Impurity in the Feed on Catalytic Dehydration of Bioethanol to Ethylene

Bioprocessing of Oat Hulls to Ethylene: Impact of Dilute HNO3- or NaOH-Pretreatment on Process Efficiency and Sustainability

“…However, due to the low quantity of impurities (∼0.5 g/L), the specific catalyst productivity to ethylene, P E , with d2 was ∼2.3% higher than that with pure alcohol dc . Using a similar catalyst, the ethylene yield was observed to increase, as the concentration of C3 -alcohols increased to ∼1 g/L, and to decrease with a further increase in impurities . With the content of organic impurities above 10 g/L and ∼0.06 g/L Na-ions in d1 , X d decreased by ∼8%RE, P E decreased by ∼17%RE, and the byproduct capacity increased by ∼26%RE (Figure c).…”

“…Using a similar catalyst, the ethylene yield was observed to increase, as the concentration of C3-alcohols increased to ∼1 g/L, and to decrease with a further increase in impurities. 42 With the content of organic impurities above 10 g/L and ∼0.06 g/L Na-ions in d1, X d decreased by ∼8%RE, P E decreased by ∼17%RE, and the byproduct capacity increased by ∼26%RE (Figure 1c). The impaired catalytic activity caused by the processing of fusel alcohol-contaminated bioethanol has been reported.…”

Industrial crude bioethanol dehydration to ethylene: Doping ZSM-5 to enhance selectivity and stability

“…Since we are currently obtaining similar results, impurities (i.e., C3H8O, C4H10O, and C5H12O) present in the top fraction bioethanol sample used in this study (i.e., 90 wt.% ethanol) do not show a negative impact on the catalytic performance (see Figure 2). In fact, Banzaraktsaeva et al [37] reported a conversion of 96% and selectivity to C2H4 of 97% for bioethanol samples (ethanol 92.5 wt.%) with an impurity concentration of 0.43 g L -1 using an Al2O3 catalyst at 400 °C, suggesting that an isopropanol concentration of up to 0.7 g L -1…”

“…benefits dehydration, as it decreases the amount of generated by-products [37]. Thus, the catalyst performance in the dehydration of top fraction of crude bioethanol would depend J o u r n a l P r e -p r o o f 16 mainly on the Si/Al ratio and dopants.…”