期刊名称：Pakistan Journal of Analytical & Environmental Chemistry
印刷版ISSN：1996-918X
电子版ISSN：2221-5255
出版年度：2021
卷号：22
期号：1
页码：150-158
DOI：10.21743/pjaec/2021.06.15
语种：English
出版社：National Centre of Excellence in Analytical Chemsitry
摘要：Cracking of edible oils occurs at high temperature and forms valued low molecular weightchemical species. The aim of the current study was to find a catalyst which can break these heavymolecules at the lower ranges of temperatures. From the analysis prospective, the non-condensablehydrocarbons (gaseous product species) were not determined and reactions study was carried outin a batch reactor. There was no evident conversion up to a temperature of 450 °C in the absenceof catalyst whereas the reaction mixture was left inside a batch reactor for a long duration of anhour. Reaction parameters, such as catalyst types (ZnO and Al2O3), amount of catalyst, reactiontemperature, residence or holding time, and heating rate to reach a reaction temperature weresystematically examined. Powdered form of catalyst samples (ZnO and Al2O3) were characterizedby using XRD, EDX, and Nitrogen adsorption isotherms. Temperatures studied over ZnO catalystwere 400 °C, 425 °C, 450 °C, 475 °C, and 500 °C. The maximum oil conversion was 81 % at atemperature of 450 °C. We observed that the conversion increases from 400 °C to 450 °C, whereasabove 450 °C it starts to decrease. However, in comparison to ZnO catalyst the reaction rate wasmuch higher over the Al2O3, i.e. a considerable conversion occurred at lower ranges oftemperatures. Thus here a different set of temperatures (330 °C, 370 °C, 390 °C, 410 °C, and430°C) were used. When reacting for an hour at a temperature of 390 °C, and in the presence of 8wt.% of Al2O3 (same catalyst mass was used in ZnO reacting system) the conversion reached to 71%. Above 390 °C the conversion decreased. Over both tested metal oxide catalysts the caloricvalue, density, flash point, and kinematic viscosity of the liquid product species were similar topetro fuels. The XRD and EDX signature of the catalyst samples corresponds to the standard ZnOand Al2O3 patterns. Finally, when compared to ZnO the better activity over the Al2O3 (higherconversion at lower temperature) catalyst can be linked with a high external surface area.
