Konverzija sladkorjev v subkritični vodi

diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje

Karin Hercog (Author), Mojca Škerget (Mentor), Željko Knez (Co-mentor)

Abstract

Namen diplomskega dela je bilo proučiti reakcijske poti razgradnje različnih sladkorjev v subkritični vodi pri danem času, temperaturi in tlaku. Pri tem smo uporabili sedem različnih sladkorjev (celobioza, fruktoza, galaktoza, glukoza, ksiloza, laktoza, saharoza). Vse reakcije smo izvajali v visokotlačnem visokotemperaturnem avtoklavu pri temperaturi 250 ˚C. Reakcije v avtoklavu za posamezni sladkor smo izvajali pri treh različnih časih, 1min, 5min in 15 min. Rezultati pridobljeni s pomočjo eksperimentalnega dela so služili pri proučevanju na katere komponente se uporabljeni sladkorji pri določeni temperaturi, času in tlaku razgradijo, kakšen je posamezen delež sladkorja in ostalih spojin dobljenih pri razgradnji. Reakcijsko zmes, t.j. vodno raztopino sladkorja smo pripravili s pomočjo destilirane vode. Določili smo deleže razgradnih produktov in sicer delež v vodi topnih produktov, delež v acetonu topnih produktov, trdni preostanek ter pline in izgube. Pri eksperimentalnem delu dobljeno vodno in acetonsko fazo smo uporabili za nadaljnje analize, kot sta HPLC analiza in UV-VIS spektrofotoskopija. S pomočjo HPLC smo določili razgradne produkte posameznega sladkorja in njihove deleže glede na celotno maso vzorca. Iz dobljenih rezultatov je razvidno, da sta ena izmed glavnih produktov razgradnje sladkorjev 5-hidroksi metil furfural in furfural. Iz rezultatov je tudi razvidno, da masni delež vodne faze v odvisnosti od časa pada, medtem ko masni delež acetonske faze s časom narašča. S časom se povečuje masa trdnega ostanka in delež nastalih plinov. Delež samega sladkorja v reakciji s časom pada, kar pomeni da se sladkor razgrajuje.

Keywords

subkritična voda;razgradnja sladkorjev;celobioza;fruktoza;galaktoza;glukoza;ksiloza;laktoza;saharoza;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2017
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[K. Hercog]
UDC:	612.396:631.461.6(043.2)
COBISS:	21060374
Views:	957
Downloads:	97
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Conversion of sugars in subcritical water
Secondary abstract:	The prupose of diploma thesis was to study the degradation of different sugars in subcritical water at given temperature and pressure. Seven different sugars (cellobiose, fructose, galactose, glucose, xylose, lactose, sucrose) were studied. All reactions were carried out in laboratory high-pressure high-temperature autocalve. Reactions were carried out at 250 ˚C and at three different times, 1min, 5min, 15min. The results obtained were used to study the degradation products of different sugars at a certain temperature, time and pressure, the amount of sugar and other compounds derived from degradation. Reaction mixture, i.e. aqueous sugar solution was prepared by using destilled water. Mass fraction of degradation products, i.e. fraction of water soluble products, fraction of aceton soluble products, solid residue and gasses were determinated. Composition of water phase and aceton phase were analysed, with HPLC and UV-Vis spectroskopy. With HPLC analysis, decomposition products of the individual sugars and their fractions were determined. From the results it is evident that two of the main decomposition products of sugars are 5-hydroxy methyl furfural and furfural. The results also show that the percentage of the aqueous phase decreases with time, while the percentage of the acetone phase increases with time.With increasing the time of reaction mass of the solid residue and the fraction of the resulting gases increase. The fraction of sugars decreases with increasing reaction time, which means that the sugar is decomposed.
Secondary keywords:	subcritical water;degradation of sugar;cellobiose;fructose;galactose;glucose;xylose;lactose;sucrose;
URN:	URN:SI:UM:
Type (COBISS):	Bachelor thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	X, 58 str.
ID:	10864730