1. Thermogravimetric, kinetic and thermodynamic behaviour of raw and hydrothermally pretreated oil cakes during pyrolysis and TG-FTIR analysis of the gaseous productsAleksandra Petrovič, Sabina Vohl, Sven Gruber, Klemen Rola, Tjaša Cenčič, Lidija Čuček, Danijela Urbancl, 2025, izvirni znanstveni članek Opis: The pyrolysis of raw and hydrothermally (HTC) pretreated pumpkin (PC) and hemp (HC) oilseed cakes was investigated for the first time using thermogravimetric, kinetic and thermodynamic analyses. The influence of the HTC pretreatment and the type of reaction liquid (whey or water) on the pyrolysis was investigated and the pyrolysis gases were analysed. The HTC pretreatment increases the biochar yield with values of up to 44 wt.% compared to raw oil cakes (∼27 wt.%). The HTC pretreatment with whey resulted in a higher energy and biochar yield and better biochar properties than the pretreatment with water. The tested oil cakes provided comparable energy yields, although HC provided higher biochar yields, while PC biochar showed higher hydrophobicity. The kinetic modelling shows that the activation energies () for the pyrolysis of the raw oil cakes varied between 93.6 and 529.9 kJ/mol for PC and between 71.3 and 669.9 kJ/mol for the HC sample. HTC pretreatment in water media increased the values, while the use of whey led to a decrease in the values. TG-FTIR analysis of the emitted gases showed that the HTC treatment affected the release of CO2 and hydrocarbons as well as the pyrolysis mechanism and reaction pathways Ključne besede: oilseed cake, hydrochar, pyrolysis, thermogravimetric analysis, kinetic analysis, gas emissions Objavljeno v DKUM: 25.04.2025; Ogledov: 0; Prenosov: 15
Celotno besedilo (9,44 MB) |
2. Sustainable hydrothermal co-carbonization of residues from the vegetable oil industry and sewage sludge : hydrochar production and liquid fraction valorisationAleksandra Petrovič, Tjaša Cenčič, Jelena Parlov Vuković, Tomislav Jednačak, Silvo Hribernik, Sabina Vohl, Danijela Urbancl, Marina Tišma, Lidija Čuček, 2024, izvirni znanstveni članek Opis: In this study, the hydrothermal co-carbonization (co-HTC) of residues from the vegetable oil industry (pumpkin oil cake– PC, hemp oil cake– HC) and sewage sludge (SS) was investigated for the first time. The co-HTC was performed at 250 C and atreatment time of 5 h. The effects of the mass ratio of the feedstocks (1:1, 1:3 and 3:1) on the properties of the HTC products were investigated using various analytical methods (NMR, XRD, 3D-EEM, FTIR, etc.). The co-HTC of SS with oil cakes resulted in improved fuel properties of the hydrochar and an increase in C content from 36.9 to 53.7 wt%, and an increase in the higher heating value (HHV) from 14.8 to 23.6 MJ/kg. The combination with HC gave hydrochars with a higher HHV and higher C content than the combination with PC. The hydrochar yield varied in the range of 39.4–55.3 wt%. NMR analysis revealed a higher proportion of aliphatic (~60 %) than aromatic compounds (~35 %) in the hydrochars, as well as a high content of orthophosphate and unsaturated fatty acids. The liquid fractions were rich in nutrients and organic compounds, but toxic to aquatic organisms. The hydrochars and liquid fractions performed well in the germination test with plant species. Ključne besede: hydrothermal co-carbonization, sewage sludge, vegetable oil industry residues, hydrochar, liquid fraction, valorisation Objavljeno v DKUM: 17.01.2025; Ogledov: 0; Prenosov: 16
Celotno besedilo (8,68 MB) |
3. Hydrothermal conversion of oilseed cakes into valuable products : influence of operating conditions and whey as an alternative process liquid on product properties and their utilizationAleksandra Petrovič, Tjaša Cenčič, Sabina Vohl, Gregor Hostnik, Matjaž Finšgar, Lidija Čuček, 2024, izvirni znanstveni članek Ključne besede: hydrothermal carbonization, hydrochar, process liquid, oilseed press cake, cheese whey, catalyst Objavljeno v DKUM: 29.08.2024; Ogledov: 64; Prenosov: 18
Celotno besedilo (7,20 MB) |