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Registration Number

0220U101747, 0119U002377 , R & D reports

Title

Acid-modified natural aluminosilicates from deposits of Ukraine as catalysts for acetalization of glycerol.

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Head

Kamalov Herbert L., Доктор хімічних наук

Registration Date

20-02-2020

Organization

Physico-Chemical Institute O. Bogatsky National Academy of Sciences of Ukraine

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 Objects of study: natural aluminosilicates, glycerol and its transformation. Aim of study: identify prospects of acid-modified natural clinoptilolite (H-KPT, Sokirnitskiy field), bentonite (H-BNT, Dashukovskiy field) and trepel (H-TRP, Konoplyanskiy field) as catalysts for processing (transformation) of glycerol (large-tonnage by-product of biodiesel production) and its derivatives in compounds with useful properties. Research methods: кinetics, potentiometry, spectrophotometry, volumetry, thin-layer and gas-liquid chromatography. The features of glycerol (GL) acetals and ketals formation in presence of nitric acid-modified samples of clinoptilolite (CPT), bentonite (BNT) and trepel (TRP) were revealed. Obtained catalysts (H-CPT, H-BNT and HTRP) have an inhomogeneous porous structure with presence of micro- and mesopores. H-CPT and H-BNT samples contain acid centers both Lewis and Brenstend, and H-TRP contain only Lewis centers. It was found that nitric acid concentration in greater extent than time of natural aluminosilicates treatments with acid affects on activity of corresponding samples. Ultrasonic grinding of H-BNT sample practically does not lead to change in its activity. In the case of H-KPT and H-TRP samples, their activity doubles after 10 min. ultrasound processing. The dominant reaction products are corresponding five-membered isomers (dioxolane). At the same time, in the case of acetals (R1 = H, R2 = H, Ph), at the deep stages of GL conversion, bis-products of “crosslinking” former with corresponding aldehydes accumulate in reaction mixture. It was revealed that in GL reaction with acetone (Ac), formaldehyde (FA) and benzaldehyde (BA), the studied catalysts are poisoned slowly, without changing their activity during 6-7 cycles. The kinetics of studied reactions is satisfactorily described by Michaelis-Menten model. With practical equality of KM constants, the Vmax values are higher for samples based on H-BNT.

Product Description

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Davtian Araksia S.
Kamalov Gerbert L.
Levchenko Olga Oleksandrivna
Chikhichin Dmytro H.

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2020-04-02