Ethanol and water aluminum reactivity12/17/2023 To convert into other transitional phases at 500 ☌. Increase in the number of acidic sites can reduce its catalytic lifespan. Its structure to increase the number of acidic sites however, the Lifespan performance than the strong acidic site. With regard to the coke effect, the weak acidic site has more satisfactory Of ZSM-5 zeolites is more crucial to reduce their strong acidic sites. Were promising from the perspective of industrialĪpplications, which is limited to unsatisfactory catalytic performanceĪnd low anticoking ability. The ability of catalysts to dehydrate ethanol to ethylene. Hierarchical porous structure with varying acidities. Or both in a sequential way to finely tune zeolite catalysts in a (2014) post-treated ZSM-5 zeolite powderīy desilication with sodium hydroxide, dealumination with oxalic acid, Or desilication and modified with phosphorous or lanthanum have been ZSM-5 zeolite catalysts treated by dealumination Has made it commercially valuable and promising for further improvement Of ethanol to ethylene at low temperatures (200–300 ☌) 5 Moreover, the ability of H-ZSM-5 to catalyze the dehydration Of 99.2% at a reaction temperature of 240 ☌. Size: 50–100 nm SiO 2/Al 2O 3 = 26) can provide a conversion rate of 98.6% and an ethylene selectivity (2010) reported that the nanoscale H-ZSM-5 zeolite powder (crystal Uses γ-alumina treated with KOH and ZnO/Al 2O 3 for ethylene production, and Halcon SD (USA) has been usingĬatalyst in their facilities. Make the reaction more economically efficient. Reduce the reaction temperature and increase the ethylene yield to (80%), researchers have been focusing on modifying the catalyst to Because a high reaction temperature ofĤ50 ☌ is required and the yield of ethylene is relatively low In the initialĭehydration of ethanol to ethylene, γ-alumina was used as aĬatalyst for the reaction. Portion of the energy cost because competing reactions into diethylĮther or acetaldehyde are favored outside the temperature range and However, the industrial applicationĪnd maintenance of such a high reaction temperature constitute a considerable Is endothermic, maintaining a high reaction temperature ranging fromġ80 to 500 ☌ is essential. The conjugate base of the catalyst then deprotonates the methyl group,Īnd the hydrocarbon rearranges into ethylene. Initially protonates the hydroxyl group, which leaves as a water molecule. 2 For example, the fast-growing fern genus Pteris is not of major economic importance but isĪ reliable source of hemicellulose that can be converted to bioethanol. That can be produced from biomass such as hemicellulose. Bioethanol is a renewable and eco-friendly energy source Therefore, dehydration of ethanol to ethylene has attracted increasingĪttention. Of petroleum that is used as a chemical feedstock for ethylene production. 2 Bioethanol producedįrom biomass fermentation is a potential alternative feedstock instead Catalyticīioethanol dehydration has been primarily used as a green alternativeįor ethylene production. Greenhouse gas emissions and dependency on limited fossil fuels. Toward the use of green alternatives for ethylene production to reduce 1 However, attention has been recently shifted Both of these catalysts were the most favorableĮthylene is traditionally produced through the steam cracking of hydrocarbons,Īnd this method remains the predominant method in the industry. Of 240 ☌ and WHSV of 1.5 h –1 when the ethanolĬoncentration was 20%. The ethylene yield and selectivity were 94.3 and 94.4%, respectively,įor the ZSM-5 zeolite catalyst modified using phosphorous at a temperature Through dealumination at a temperature of 220 ☌ and WHSV ofĢ.5 h –1 when the ethanol concentration was 95%. The results revealed that the ethylene yield and selectivity wereĩ8.5 and 100%, respectively, for the ZSM-5 zeolite catalyst modified Method, temperature-programmed desorption of ammonia gas, thermogravimetricĪnalysis, X-ray photoelectron spectroscopy, and X-ray diffraction. The catalysts were characterized using the Brunauer–Emmett–Teller Or desilication and by using the impregnation method with phosphorousĪnd lanthanum], weight hourly space velocity (WHSV), ethanol concentration,Īnd reaction temperature were investigated to obtain optimal reactionĬonditions. Experimental conditions including the catalystĪnd ZSM-5 zeolite catalyst modified using two-stage through dealumination Prepared for ethanol dehydration in a fixed-bed reactorĪcted as strong active acidic catalysts under reaction conditionsĪt lower temperatures.
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