Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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  • Article
    Citation - WoS: 21
    Citation - Scopus: 23
    Lithium: an Energy Transition Element, Its Role in the Future Energy Demand and Carbon Emissions Mitigation Strategy
    (Elsevier Ltd, 2024) Chandrasekharam,D.; Şener,M.F.; Recepoğlu,Y.K.; Isık,T.; Demir,M.M.; Baba,A.
    Energy transition elements (Li, Ni, Co, Fe, Cu) are gaining importance due to their ability to provide energy and play an important role as primary energy sources. Because of the energy density and power density, Li-ion batteries have the edge over other batteries. Li is distributed in various rock-forming minerals and brines, and geothermal waters. Though lithium-bearing minerals are spread over a broad geographic region, these minerals are confined to certain countries with substantial economic potential. Li is extensively used in batteries, and battery-driven vehicles are growing exponentially to meet the carbon reduction goal of the Paris agreement in 2015 and signed by more than 50 percent of the countries. Nearly 55 million cars supported by Li batteries are expected to roll out by 2030. While this is the demand, its occurrence and concentration/extraction processes are not keeping pace with this demand. The extraction of Li from its ore is an energy-intensive process involving many fossil fuel-based energies. To recover one ton of Li metal, nearly 5 to 6 tons of CO2 is emitted. The CO2 emissions of 28 kWh LFP, NMC, and LMO batteries vary from 5600 to 2705 kg CO2-eq. The end-of-life emissions of an internal combustion engine (ICE) vehicle are 400 kg CO2/vehicle, while Li Battery supports 500 kg/vehicle. The quantity of Li required for a 24 kWh average capacity leaf battery is about 137 g/kWh. While emissions are associated with the manufacturing of the batteries, emissions are also associated with a way that while they are recharged as the recharging source is fossil fuel-based energy. The best option to meet zero net carbon emissions by 2050, as envisaged by International Energy Agency (IEA), is to recover Li from geothermal brines and use geothermal energy for recharging. While hydrothermal energy sources are site-specific, enhanced geothermal system (EGS) based geothermal energy is not site-specific and is found wherever high radiogenic granites are available. High radiogenic granites are widely distributed, and heat recovered from EGS sources can provide clean energy and heat. Extraction of lithium from geothermal waters and using geothermal energy for recharging the batteries will drastically reduce CO2 emissions. It will drive the world towards Net Zero Emissions (NZE) scenario in the future. This is being practiced in Turkey. Future research should develop technology to recover Li from geothermal fluids with low concentration and support EGS development. © 2024 Elsevier Ltd
  • Article
    Citation - WoS: 6
    Citation - Scopus: 8
    Thermal Liquefaction of Olive Tree Pruning Waste Into Bio-Oil in Water and Ethanol With Naoh Catalyst
    (Elsevier B.V., 2024) Öcal,B.; Recepoğlu,Y.K.; Yüksel,A.
    In this study the effect of catalysts and solvents at varying temperatures on the production of bio-oil from olive tree pruning waste (OPW). The thermal liquefaction process was conducted at 200 °C, 225 °C, and 250 °C for 90 min, employing either water or ethanol as solvents, with alkaline catalysts (0.125 M, 0.25 M, and 0.5 M NaOH) introduced for the first time. Raw material, solid byproducts, and bio-oil samples underwent FTIR analysis for structural changes, TGA for proximate analysis, and GC-MS for bio-oil analysis. Results revealed that NaOH enhanced biomass conversion in water, yet didn't increase bio-oil yield, whereas in ethanol, biomass conversion was relatively lower, but bio-oil yield improved despite the adverse effects of catalyst. The highest biomass conversion (94 %) was achieved at 250 °C with 0.5 M NaOH, but the maximum bio-oil yield (25 %) occurred without a catalyst in water. Conversely, the highest bio-oil yield (55 %) was attained using ethanol without a catalyst at 250 °C. © 2024 Energy Institute
  • Article
    Citation - WoS: 15
    Citation - Scopus: 15
    Granulation of Hydrometallurgically Synthesized Spinel Lithium Manganese Oxide Using Cross-Linked Chitosan for Lithium Adsorption From Water
    (Elsevier B.V., 2024) Recepoğlu,Y.K.; Arabacı,B.; Kahvecioğlu,A.; Yüksel,A.
    A drastic increase in demand for electric vehicles and energy storage systems increases lithium (Li) need as a critical metal for the 21st century. Lithium manganese oxides stand out among inorganic adsorbents because of their high capacity, chemical stability, selectivity, and affordability for lithium recovery from aqueous media. This study investigates using hydrometallurgically synthesized lithium manganese oxide (Li1.6Mn1.6O4) in granular form coated with cross-linked chitosan for lithium recovery from water. Characterization methods such as SEM, FTIR, XRD, and BET reveal the successful synthesis of the composite adsorbent. Granular cross-linked chitosan-coated and delithiated lithium manganese oxide (CTS/HMO) adsorbent demonstrated optimal removal efficiency of 86 % at pH 12 with 4 g/L of adsorbent dosage. The Langmuir isotherm at 25 °C, which showed monolayer adsorption with a maximum capacity of 4.94 mg/g, a better fit for the adsorption behavior of CTS/HMO. Adsorption was endothermic and thermodynamically spontaneous. Lithium adsorption followed the pseudo-first-order kinetic model. © 2024