Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Selective Catalytic Hydrogenation of Cellulose into Sorbitol with Ru-Based Catalysts(2022) Orak, C.; Sapmaz, A.; Yüksel Özşen, A.Sorbitol is one of the platform chemicals and can be produced from various renewable and sustainable sources via different processes. Hydrothermal liquefaction is an effective and promising approach to produce sorbitol, since the subcritical reaction media and appropriate catalysts provide a selective production of platform chemicals. In this study, sorbitol was produced from different renewable sources (cellulose and glucose) in the presence of Ru-based catalysts (Ru/SiO2, Ru/AC, Ru/SBA-15, and Ru/SBA-15-SO3) under subcritical conditions. The highest cellulose conversion was achieved as 90% in the presence of Ru/SBA-15-SO3 for 1 h of reaction duration. The highest sorbitol yield (%) by hydrothermal liquefaction of cellulose was obtained as 6.2% by using Ru/AC for 1 h of reaction duration. A total of 99.9% of glucose conversion was achieved in the presence of all catalysts. The highest sorbitol yield (%) by hydrothermal liquefaction of glucose was found as 3.8% for 1 h of reaction duration. Owing to the results of GC-MS analysis, the intermediate products were identified, and, thus, a reaction pathway was proposed. © 2022 TUBITAK. All rights reserved.Article Citation - WoS: 10Citation - Scopus: 11Liquefaction of Oak Wood Using Various Solvents for Bio-Oil Production(AMER CHEMICAL SOC, 2023) Öcal, Bulutcem; Yüksel, AslıRapidly increasing global energy demand resulting from the growing population and worldwide development has increased the consumption of limited fossil fuel. The usage causes severe environmental deterioration by CO2 emission, which has sparked interest in finding green, renewable, and sustainable alternative sources of energy. Bio-oil, derived from several biomasses via liquefaction, is a promising candidate to replace fossil fuels. Turkey's land (27%) is covered with forested areas (consisting of mostly oak trees). Therefore, it has great potential for cheap lignocellulosic feedstock forest residues from industrial applications and harvesting. In the present study, the thermal liquefaction of oak wood particles (OWP) was performed using various solvents in addition to water, namely, ethanol, 1-butanol, and 1,4-dioxane. The experiments were carried out in a batch reactor for 1 and 2 h residence times at different temperatures (210, 240, and 270 degrees C). Bio-oil samples obtained at 270 degrees C and a 1 h residence time determined as optimum conditions were analyzed with TGA, CHNS elemental analysis, FTIR, and GC-MS. 1,4-Dioxane showed the best performance in yielding the maximum bio-oil with 51.8% at those conditions. The higher heating values of the bio-oils ranged from 22.1 to 35 MJ/kg. Phenolic groups were the predominant components of bio-oil produced from OWP, while the intensity of alcohols, ketones, and acids varied based on used solvents. Based on energy recovery calculations, the enhancement of pristine OWP's energy efficiency depended on bio-oil yield, and quality was confirmed for all solvent types (1,4-dioxane > 1-butanol > water > ethanol).