magistrsko delo študijskega programa II. stopnje
Tjan Smrečnik (Author), Mojca Škerget (Mentor), Željko Knez (Co-mentor)

Abstract

Z raziskovalnim laboratorijskim delom smo želeli preučiti možnost hidrolize kostanjevih taninov s subkritično vodo, ki ima lahko pri povišani temperaturi in tlaku kislinsko-bazne katalizatorske lastnosti, kar nam omogoča, da jo uporabimo pri kemijski reakciji hidrolize kot reaktant in katalizator. S pomočjo programa Design Expert smo tudi določili optimalne pogoje za pridobivanje galne kisline. Izrednega pomena je, da lahko vodo po končani uporabi recikliramo, kar je zaradi vse strožjih okoljskih zahtev vsekakor izrednega pomena. V laboratoriju smo izvedli kislinsko hidrolizo tudi s klorovodikovo kislino, za primerjavo z dobljenimi rezultati pri hidrolizi s subkritično vodo. V vzorcih smo določali vsebnost totalnih taninov, totalnih fenolov, totalnih ogljikovih hidratov in totalnih flavonoidov. Dodatno smo določali tudi vsebnost galne kisline, elagne kisline, kastalagina, 1-galloy-kastalagina in veskalagina. Ugotovili smo, da je hidroliza tanina možna s subkritično vodo. Na potek hidrolize imajo velik vpliv temperatura, čas, hitrost segrevanja in nihanje temperature. S pomočjo programa smo optimizirali tudi izkoristek galne kisline v odvisnosti od časa in temperature. Optimalne pogoje smo določili pri temperaturi 127,85 °C in času 53,29 minut.

Keywords

tanini;hidroliza;subkritična voda;fenoli;galna kislina;magistrske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [T. Smrečnik]
UDC: 66.094.941(043.2)
COBISS: 20694806 Link will open in a new window
Views: 1280
Downloads: 159
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Other data

Secondary language: English
Secondary title: Hydrolysis of tannins with subcritical water - determination of optimal conditions
Secondary abstract: This research and laboratory study investigated the possibility of hydrolysis of chestnut tannins by subcritical water, which can have acid-base catalytic properties when the temperature and pressure rise. This enables the use of it with chemical reaction of hydrolysis as a reactant and catalyst. The assistance of the program Design Expert ensured defining optimal conditions for extracting Gallic acid. Due to more and more severe environmental requirements it is significant that this water can be recycled after finished using it. In the laboratory also an acid hydrolysis by hydrochloric acid was carried out in order to compare it with the results received from hydrolysis by subcritical water. In the samples the content of total tannins, total phenols, total carbohydrates and total flavonoids was determined. Additionally also the content of Gallic acid, Ellagic acid, Castalagin, 1-Galloy-Castallgin and Vescalagin was determined. With this study it can be concluded that tannin hydrolysis by subcritical water is possible. The factors of temperature, time, speed of heating and temperature oscillations have a great impact on the process of hydrolysis. With the help of computer program also the efficiency of Gallic acid could be optimized depending on time and temperature. Optimal conditions were determined at the temperature of 127. 85 °C and time of 53. 29 minutes.
Secondary keywords: tannins;hydrolysis;subcritical water;phenols;gallic acid;
URN: URN:SI:UM:
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: X, 57 str.
ID: 10842647