Chemical Engineering / Kimya Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/14
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Article Citation - WoS: 4Citation - Scopus: 5Breakthrough Curve Analysis of Phosphorylated Hazelnut Shell Waste in Column Operation for Continuous Harvesting of Lithium From Water(Elsevier, 2024) Recepoğlu, Yaşar Kemal; Arar, Ozguer; Yuksel, AsliIn batch-scale operations, biosorption employing phosphorylated hazelnut shell waste (FHS) revealed excellent lithium removal and recovery efficiency. Scaling up and implementing packed bed column systems necessitates further design and performance optimization. Lithium biosorption via FHS was investigated utilizing a continuous-flow packed-bed column operated under various flow rates and bed heights to remove Li to ultra-low levels and recover it. The Li biosorption capacity of the FHS column was unaffected by the bed height, however, when the flow rate was increased, the capacity of the FHS column decreased. The breakthrough time, exhaustion time, and uptake capacity of the column bed increased with increasing column bed height, whereas they decreased with increasing influent flow rate. At flow rates of 0.25, 0.5, and 1.0 mL/min, bed volumes (BVs, mL solution/mL biosorbent) at the breakthrough point were found to be 477, 369, and 347, respectively, with the required BVs for total saturation point of 941, 911, and 829, while the total capacity was calculated as 22.29, 20.07, and 17.69 mg Li/g sorbent. In the 1.0, 1.5, and 2.0 cm height columns filled with FHS, the breakthrough times were 282, 366, and 433 min, respectively, whereas the periods required for saturation were 781, 897, and 1033 min. The three conventional breakthrough models of the Thomas, Yoon-Nelson, and Modified Dose-Response (MDR) were used to properly estimate the whole breakthrough behavior of the FHS column and the characteristic model parameters. Li's extremely favorable separation utilizing FHS was evidenced by the steep S-shape of the breakthrough curves for both parameters flow rate and bed height. The reusability of FHS was demonstrated by operating the packed bed column in multi-cycle mode, with no appreciable loss in column performance.Article Citation - WoS: 7Citation - Scopus: 7Cross-Linked Phosphorylated Cellulose as a Potential Sorbent for Lithium Extraction From Water: Dynamic Column Studies and Modeling(American Chemical Society, 2022) Recepoğlu, Yaşar Kemal; Yüksel, AslıPhosphorylated functional cellulose was cross-linked with epichlorohydrin at different ratios because it is a very hydrophilic substance that instantly swells to form a hydrogel when it comes into contact with water. It was aimed to utilize a continuously packed bed column to recover lithium from water under varying operating conditions such as flow rate and bed height. The characterization results confirmed cross-linking based on morphology, structure, surface area, and thermal stability differences. Lithium recovery was more efficient with a low flow rate, but the dynamic sorption process was independent of bed height. The total capacities at the three flow rates with 1.5 cm bed height were 33.56, 30.15, and 25.54 mg g-1, and the total saturation times at the three different bed heights with 0.5 mL min-1 flow rate were 659, 1001, and 1007 min, respectively. Only 15.75 mL of 5% H2SO4 solution was required to desorb approximately 100% of Li from the saturated sorbent.Article Citation - WoS: 13Citation - Scopus: 11Valorization of Olive Tree Pruning Waste for Potential Utilization in Lithium Recovery From Aqueous Solutions(Springer, 2022) Nampeera, Jackline; Recepoğlu, Yaşar Kemal; Yüksel, AslıOlive tree pruning waste, mainly composed of olive branches, was converted into a value-added and sustainable product capable of lithium as a biosorbent through alkali treatment and phosphorylation reaction. Characterization studies were performed by SEM–EDX, XPS, FTIR, and TGA. Factors affecting biosorption mechanism, i.e., sorbent dosage, pH, initial Li+ concentration and temperature, and competitive ions’ presence, were investigated the synthesized functionalized olive branches (FOB). A commercial lithium selective resin, Lewatit TP 260, was also compared with FOB in batch and column studies. The Freundlich model fits adsorption isotherms better than the Langmuir model, with a maximum adsorption capacity of 6.7 mg/g at 30 °C and pH 7–8. Kinetic studies proved fast kinetics and equilibrium were attained in 6 min, while thermodynamic studies showed an exothermic (Δ Ho= - 17.52 kJ/ mol) , spontaneous reaction Δ Go< 0 at all temperatures), and increased randomness Δ So= + 24.27 J/ mol. K) at the interaction interface. Column studies revealed that although Lewatit TP 260 resin showed higher sorption capacity, its desorption efficiency (50.42%) was lower than that of FOB (99.9%), and the degree of column utilization of FOB (56.81%) was better than Lewatit TP 260 resin’s (16.0%). The findings were encouraging in the successful synthesis of a promising biosorbent from an abundant waste in Turkey for use in sustainable lithium recovery from aqueous sources. Graphical abstract: [Figure not available: see fulltext.]Article Citation - WoS: 17Citation - Scopus: 16Synthesis, Characterization and Adsorption Studies of Phosphorylated Cellulose for the Recovery of Lithium From Aqueous Solutions(Editura Acad Romane, 2021) Recepoğlu, Yaşar Kemal; Yüksel, AslıIn this study, pristine cellulose was functionalized by the phosphorylation reaction to make it suitable for lithium separation. After characterization studies of the synthesized adsorbent with SEM, EDX, FTIR, TGA and XPS, the effects of various parameters on the lithium uptake capacity of the adsorbent were examined. The analysis of equilibrium data by several adsorption models showed that maximum adsorption capacity of the adsorbent was found to be 9.60 mg/g at 25 degrees C by the Langmuir model. As initial concentration and contact time increased, adsorption capacity also increased, however, mild temperature (25-35 degrees C) and pH (5-6) were better for the adsorption of lithium. 80% of lithium adsorption within three minutes proved the fast kinetic nature of the adsorbent. A 99.5% desorption efficiency of lithium was achieved with 0.5 M H2SO4, among HCl and NaCl with different molarities. Phosphorylated cellulose was shown to be a favorable adsorbent for the recovery of lithium from aqueous solutions.Article Citation - WoS: 25Citation - Scopus: 26Phosphorylated Hazelnut Shell Waste for Sustainable Lithium Recovery Application as Biosorbent(Springer, 2021) Recepoğlu, Yaşar Kemal; Yüksel, AslıHazelnut shell waste was phosphorylated to develop a novel biosorbent based on natural renewable resource for the recovery of lithium from aqueous solution. For the synthesized biosorbent, the surface morphology and mapping by SEM-EDS, chemical properties by FTIR, elemental analysis by XPS, specific surface area by BET, crystallinity by XRD and thermal properties by TGA were elucidated elaborately. The influence of biosorbent dosage, initial concentration, temperature, contact time, pH and coexisting ions were investigated. The equilibrium sorption capacity reached 6.03 mg/g under optimal conditions (i.e., biosorbent dosage of 12.0 g/L, initial Li concentration of 100 mg/L, pH value of 5.8, sorption temperature of 25 degrees C, and sorption time of 6 min). According to the sorption behavior of the phosphorylated hazelnut shell waste the Freundlich model proved to be more suitable than the Langmuir model indicating maximum sorption capacity as 7.71 mg/g at 25 degrees C. Thermodynamic parameters obtained by different isokinetic temperatures disclosed that the ion exchange reaction was feasible, spontaneous, and exothermic where the interaction between biosorbent surface and solvent plays an important role. A preliminary test on the Li recovery from geothermal water was also performed to check its applicability in a real brine. Desorption studies at 25 degrees C revealed that relatively higher desorption efficiency and capacity were achieved at 97.4% and 5.93 mg/g, respectively with a 1.0 M H2SO4 among other regenerants (i.e., HCl and NaCl). Concentrations of Li and the other cations were determined via ICP-OES. Due to such outstanding features, the novel phosphorylated hazelnut shell waste had great potential for lithium recovery from aqueous solution by being added value as a waste and recovering a strategic element of modern life simultaneously. [GRAPHICS] .Article Citation - WoS: 17Citation - Scopus: 19Effect of Operational Conditions on Separation of Lithium From Geothermal Water by ?-Mno2 Using Ion Exchange–membrane Filtration Hybrid Process(Taylor and Francis Ltd., 2018) Recepoğlu, Yaşar Kemal; Kabay, Nalan; Yoshizuka, Kazuharu; Nishihama, Syouhei; Yılmaz İpek, İdil; Arda, Müşerref; Yüksel, MithatA hybrid system coupling ion exchange and ultrafiltration (UF) was employed to separate lithium from lithium-spiked geothermal water. The effect of process parameters such as adsorbent type, adsorbent dosage, permeate flow rate, and replacement speeds of fresh and saturated adsorbents have been evaluated to determine the efficiency of the hybrid system. According to the results obtained using λ-MnO2 derived from spinel-type lithium manganese dioxide, the optimal operating conditions to separate lithium from geothermal water were found with powdery λ-MnO2 with an adsorbent concentration of 1.5 g adsorbent/L solution, replacement rates of fresh and saturated adsorbents of 6.0 mL/min, and a permeate flow rate of 5.0 mL/min. The ion exchange–UF hybrid system providing an advantage to work with very fine particles easily can be considered as a favorable process for the separation of lithium from geothermal water.