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Registration Number

0215U007242, 0114U006039 , R & D reports

Title

Pyrolysis with the use of nanocatalysts MexOy/SiO2 the way to get second-generation biofuels via processing of fatty acids, triglycerides and renewable plant biomass

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Head

Kulik Tetyana Volodimirivna,

Registration Date

19-02-2015

Organization

Institute of Surface Chemistry of the National Academy of Sciences of Ukraine

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The purpose of work is a synthesis of nanocomposites MexOy/SiO2 based on rare-earth metals in order to find a high-performance nanocatalysts for pyrolytic conversion of biomass into II generation biofuels; determining the effect of concentration of the rare earth element oxide on the surface of nanocomposite on reactivity of nanooxides in thermal transformation reactions of fatty acids - component of vegetable triglycerides, obtaining a correlations between kinetic parameters (activation energy Eact) of catalytic reaction and structural characteristics; the establishment of optimal conditions for synthesis of new nanocomposites. Research methods are temperature programmed desorption mass spectrometry (TPD MS), adsorption methods of analysis. In order to find potential catalysts for the pyrolytic conversion of biomass into II generation biofuels, a comparative analysis of thermochemical transformations of aliphatic carboxylic acids on the surface of nanocomposites CeO2/SiO2 with a crystallite size of cerium ~ 3 nm and the concentration of 6-24% by weight was carried out by TPD MS. For this purpose, the functionalization of synthesized nanocomposite CeO2/SiO2 by a series of aliphatic carboxylic fatty acids was done. It has been determined that the temperature of the maximum reaction rate Tmax in the conversion of fatty acids to ketones on the surface of nanocomposite CeO2/SiO2 increases in the homologous series with increasing number of methylene groups in the molecule. The shift of temperature is ?Tmax ~ 130 ° C when compared to the conversion of acetic acid and stearic acid. Respectively, the increase of the activation energy for the conversion of stearic acid as compared with acetic acid is ?Eakt ~ 30 kJ/mol. Detailed studies of thermal transformations of the grafted groups ?Si-O-Ce-(O-Acac)2 in the topochemical synthesis of CeO2nanoparticles on the silica surface, depending on the concentration and quantity of laying of Ce(Acac)3 modifier have been done. The kinetic parameters have been calculated and the mechanism of formation of acetone as a result of thermal transformation of grafted groups ?Si-O-Ce-(O-Acac)2 has been proposed. The basic laws of thermal transformations of the grafted groups ?Si-O-Ce-(O-Acac)2 have been established. It has been shown that the development of nanocatalysts based on cerium oxide is promising as a temperature of maximum speed Tmax of catalytic reaction of forming of symmetrical ketones on the surface of nanocomposite CeO2/SiO2 decreases with increasing concentration of cerium oxide nanoparticles in the nanocomposites. Respectively, the activation energy decreases, and therefore energy efficiency of the use of such catalysts will be higher. The obtained new knowledge can be the basis for the development of nanotechnologies of pyrolytic nanocatalysis for obtaining II generation biofuel from renewable natural resources, such as vegetable oils, waste oils and fats containing substantial amounts of free fatty acids, and biomass, which can contain besides the triglycerides, free fatty acid and lignocellulose. These green technologies can reduce energy dependence on imported fossil hydrocarbons and solve environmental problems of production of I generation biodiesel.

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Б.Б.Паляниця
К.С.Кулик
Кулик Т.В.
Л.Р.Азізова
М.В.Борисенко
О.О. Дудік

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2020-04-02