Browsing by Author "Goktepeli, G."

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Citation - WoS: 2
Citation - Scopus: 3
Development of Sustainable Resource Recovery Approach From Agro-Industrial Wastes by Revealing the Economic Added Value Potential
(Springer Nature, 2024) Goktepeli, G.; Ozgan, A.; Onen, V.; Ahmetli, G.; Kalem, M.; Yel, E.
The physicochemical sludge generated from treatment of effluents from marble processing facilities should be managed properly due to their adverse effects on the environment. These sludges can be evaluated as catalyst in pyrolysis since they consist of some inorganics such as CaCO3 and Al or Fe salts which come from marble structure and coagulation–flocculation treatment of the effluent, respectively. Therefore, in this study, an approach for sustainable resource recovery from agro-industrial wastes (olive pomace) was developed by offering a solution to the two different waste types via pyrolysis and by revealing economic value-added potential of the process. Olive pomace-marble sludge catalyst mixtures were pyrolyzed in a laboratory-scale fixed bed batch pyrolysis system by using four catalyst dosages (10, 20, 30 and 50%) and three pyrolysis temperatures (300, 500 and 700 °C) at 5 °C/min heating rate. Pyrolysis oils and gases were analyzed with GCMS-FID and FTIR for evaluating the potential of economically valuable organic compounds. Organic compounds having extensive usage areas, such as feedstock for surfactants production, emollient, flavoring and softening, and high economic value in the market, such as 1-Pentadecanol, 2-Pentadecanone and Octane, were identified especially in catalytic pyrolysis liquid products. For instance, the potential profit that can be obtained from the conversion of olive pomace to ‘2-pentadecanone’ compound found in catalytic pyrolysis oil produced in this study is around 2.46 × 1013 USD for 2021/22 years at ideal conditions. Consequently, the presented approach contributes to sustainable circular economy via converting wastes into economic value instead of conventional waste disposal methods. Graphical abstract: (Figure presented.). © The Author(s) under exclusive licence to Iranian Society of Environmentalists (IRSEN) and Science and Research Branch, Islamic Azad University 2024.
Effects of Green and Innovative Pretreatment Techniques on Kinetic Parameters of Sunflower Seed Husk
(Gumushane University, 2024) Goktepeli, G.
The effects of green pretreatment processes, such as ultrasonic process (US) and deep eutectic solvent (DES), applied to the biomass on kinetic parameters are as important as their effects on characteristic properties. Process conditions and course of reaction progression depend on the knowledge about kinetic parameters, activation energy and reaction model of thermal degradation in scale-up studies. Therefore, in this study, the change in the kinetic parameters with US applied with both distilled water and DES (glycerol:sodium acetate) at 100 W power and 20 kHz frequency for 10 minutes to sunflower seed husk (SSH) was revelaed. Isoconversional methods Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) were preferred for the evaluation of activation energy of SSH and pretreated SSH at 15°C/min, 20°C/min and 25°C/min heating rates. US pretreatment with DES instead of water resulted in increment of average activation energy values (Ea) from 113.13 to 143.65 kJ/mol in the KAS method. Ea values for all SSH samples changed in the range of 87.72-143.65 kJ/mol and higher Ea values was obtained with KAS method for pretreated SSH samples. Consequently, the use of DES in US pretreatment was more effective to change kinetic parameters of SSH compared to water. © 2024, Gumushane University. All rights reserved.
Citation - Scopus: 1
Marble Processing Effluent Treatment Sludge in Waste Poly(ethylene Terephthalate) Pyrolysis as Catalyst–ii: Recovery From Pyrolytic Fluids
(Institute for Ionics, 2024) Ahmetli, G.; Ozgan, A.; Onen, V.; Kalem, M.; Goktepeli, G.; Yel, E.
In this study, feedstock and energy recovery potential from fluid fraction of catalytic pyrolysis of poly(ethylene terephthalate) plastic waste in the presence of marble processing effluent physico-chemical sludge catalyst were investigated. The contribution of the study is both symbiotic disposal of two kinds of wastes and produced valuable products. The pyrolysis fluid products obtained at 300–700 °C and 10–50% catalyst dose were inquired via chemical, thermogravimetric and chromatographic means. Main recoverable compounds were in the benzene group, followed by the esters, alcohols and ketones. The variety of organic components in pyrolytic gas was detected in aliphatic compounds (alkanes and alkenes) followed by the oxygenated organics and aromatic compounds. Benzoic acid, Methanone diphenyl(benzophenone), 1,1biphenyl, 9H Fluorene, Octane, Methyl benzene, some Benzene and Heptene derivatives were the components that are easily recoverable from the pyrolytic fluids. All these recoverable components are economically important feedstocks utilized in industrial processes. Optimization of recovery and enrichment methods of these compounds is recommended for further study. More thermally stable products formed and the higher final thermal residue of pyrolytic oil and oligomer products were obtained at higher pyrolysis temperatures. Their T5, T10 and T50 values varied between 36–44, 44–54, and 72–84 °C, respectively, while they were 131–154, 141–160 and 217–313 °C for oligomers. Calorific values of the produced oligomers were in the range of 5541–6984 cal/g. This study indicated that the thermochemical degradation of poly(ethylene terephthalate) with marble sludge catalyst is important approach for material and energy recovery in terms of fluid products of the process. © The Author(s) under exclusive licence to Iranian Society of Environmentalists (IRSEN) and Science and Research Branch, Islamic Azad University 2024.