Browsing by Author "Kucuk, Mehmet Masuk"

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Applications on Agricultural and Forest Waste Adsorbents for the Removal of Lead (Ii) From Contaminated Waters
(Springer, 2012) Saka, Cafer; Sahin, Omer; Kucuk, Mehmet Masuk
At present, there is growing interest in using low cost, commercially available materials for the adsorption of heavy metals. The major advantages of adsorption technologies are its effectiveness in reducing the concentration of heavy metal ions to very low levels and the use of inexpensive adsorbent materials. In this review, agricultural and forest waste adsorbents were used to remove Pb2+ ions in wastewater treatment, and their technical feasibilities were reviewed in studies mainly from 2000 to 2010. They all were compared with each other by metal binding capacities, metal removal performances, sorbent dose, optimum pH, temperature, initial concentration and contact time. Although commercial activated carbon is widely used in wastewater treatment applications, it has high costs. The use of agricultural by-products as adsorbent material to purify heavy metal contaminated water has become increasingly popular through the past decade because they are less expensive, biodegradable, abundant and efficient. Instead of activated carbon, this study was focused on the inexpensive materials such as agricultural and forest waste. It was shown that these alternative adsorbents had sufficient binding capacity to remove Pb2+ ions from wastewater.
Evaluation of Eremurus Spectabilis for Production of Bio-Oils With Supercritical Solvents
(Elsevier Science Bv, 2015) Aysu, Tevfik; Demirbas, Ayhan; Bengu, Aydin Sukru; Kucuk, Mehmet Masuk
Eremurus spectabilis samples were liquefied in organic solvents (methanol, ethanol and acetone) with (sodium hydroxide and ferric chloride) and without catalyst in a cylindrical reactor at temperatures of 270, 290 and 310 degrees C under supercritical conditions. The effects of liquefaction parameters such as temperature, catalyst and solvent on product yields were investigated. The liquid products were extracted with diethyl ether and benzene using an extraction procedure. The product yields in supercritical methanol, ethanol and acetone were found to as 41.6%, 53.8% and 64.3% in the non-catalytic runs at 310 degrees C, respectively. The highest conversion was obtained in supercritical acetone in the presence of ferric chloride (10%) at same temperature in the catalytic runs. The produced liquids in acetone were analyzed and characterized by elemental, Fourier transform infrared spectroscopy (FT-IR), gas chromatography-mass spectrometry (GC-MS). The liquid products (bio-oils) obtained with acetone contained various types of components including aromatics, nitrogenated and oxygenated compounds. As the bio-oils obtained exhibit high heat values, E. spectabilis is presented as a potential feedstock candidate for production of bio-fuels or valuable chemicals. (C) 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Liquefaction of Giant Fennel (Ferula Orientalis L.) in Supercritical Organic Solvents: Effects of Liquefaction Parameters on Product Yields and Character
(Elsevier, 2013) Aysu, Tevfik; Kucuk, Mehmet Masuk
Ferule orientalis L stalks were liquefied in an autoclave in supercritical organic solvents (methanol, ethanol, 2-propanol, acetone and 2-butanol) with (NaOH, Na2CO3, ZnCl2) and without catalyst at five different temperatures ranging from 240 degrees C to 320 degrees C. The amounts of solid (unconverted raw material), liquid (bio-oil) and gas produced, as well as the composition of the resulting liquid phase, were determined. The effects of various parameters such as temperature, solvent, catalyst and ratio of catalyst on product yields were investigated. The results showed that conversion highly depends on the temperature and catalyst. The highest bio-oil yield (53.97%) was obtained using acetone with 10% zinc chloride at 300 degrees C. The liquid products were extracted with benzene and diethyl ether. Some of selected liquid products (bio-oils) were analyzed by elemental, FT-IR and GC-MS. 126 different compounds were identified by GC-MS in the liquid products obtained in ethanol at 300 degrees C. (C) 2013 Elsevier B.V. All rights reserved.
Liquefaction of Giant Reed (Arundo Donax L.) by Supercritical Fluid Extraction
(Elsevier Sci Ltd, 2013) Aysu, Tevfik; Kucuk, Mehmet Masuk
Air dried and ground Arundo donax L. was subjected to supercritical and catalytic fluid extraction by using organic solvents (methanol, ethanol, acetone and 2-butanol) with (NaOH or Na2CO3) and without catalyst at different temperatures. The liquid products obtained were extracted by liquid-liquid extraction with benzene and diethyl ether. The percentage of yields of liquid products from supercritical extraction by methanol, ethanol, acetone and 2-butanol conversions were 40.3%, 60.7%, 73.58% and 82.1% at 558 K respectively. The highest conversion was obtained in 2-butanol without using catalyst at 558 K. As for the catalytic run, it was with NaOH in ethanol at the same temperature (558 K). Two of selected yields of conversion were analyzed by GC-MS. (C) 2012 Elsevier Ltd. All rights reserved.
Liquefaction of Typha Latifolia by Supercritical Fluid Extraction
(Elsevier Sci Ltd, 2012) Aysu, Tevfik; Turhan, Mehmet; Kucuk, Mehmet Masuk
Milled Typha latifolia stalk mill was converted to liquid products by using organic solvents (methanol, ethanol, acetone and 2-butanol) with catalysts (10% NaOH or Na2CO3) and without catalyst in an autoclave at temperatures of 518, 538 and 558 K. The products were extracted by liquid-liquid extraction (benzene and diethyl ether). The percentage yields from supercritical methanol, ethanol, 2-butanol and acetone conversions were 55.0, 58.5, 62.7 and 70.5 at 538 K, respectively. In the catalytic run with NaOH, the highest conversion was obtained by using ethanol as a solvent at the same temperature. Conversion yields were analyzed by GC-MS. The aim of the present study was to obtain an alternative for petroleum derived fuels or chemical raw materials. (C) 2011 Elsevier Ltd. All rights reserved.
Optimization of Process Variables for Supercritical Liquefaction of Giant Fennel
(Royal Soc Chemistry, 2014) Aysu, Tevfik; Kucuk, Mehmet Masuk; Demirbas, Ayhan
Milled giant fennel (Ferula orientalis L.) stalks were treated in supercritical solvents in the presence of catalyst in a high pressure reactor. Effects of process variables including temperature (from 240 to 320 degrees C), solvent (2-propanol, 2-butanol, and acetone), catalyst (Na2CO3, NaOH, and ZnCl2), particle size (from 0.224 > D-p > 0.150 to 0.850 > D-p > 0.425), solvent/mass ratio (from 50/5 to 50/15) and reaction time (from 45 to 95 min) on product yields were investigated. The amounts of solid, liquid and gas produced, as well as the properties of the resulting bio-oils were determined. Temperature, catalyst and reaction time were major factors affecting the product yields and composition of bio-oils. The highest conversion (liquid + gas products) of 73.48% was achieved in acetone with 10% zinc chloride at 320 degrees C. Acetone as solvent, zinc chloride (10%) as catalyst, 0.224 > D-p > 0.150 as particle size, 50/5 as solvent/mass ratio, and 80 minutes as reaction time provide the optimum conditions for the supercritical liquefaction of Ferula orientalis L. The liquid products (bio-oils) obtained at 300 degrees C were analyzed by gas chromatography-mass spectrometry (GC-MS). The bio-oils which contained a higher amount of carbon and hydrogen than that of the original raw material had higher heating values ranging from 23.66 to 26.17 MJ kg(-1).
Preparation and Characterization of Activated Carbon From Pine Cone by Microwave-Induced Zncl2 Activation and Its Effects on the Adsorption of Methylene Blue
(Springer, 2014) Ozhan, Abdurrahman; Sahin, Omer; Kucuk, Mehmet Masuk; Saka, Cafer
In this work, activated carbon prepared from pine cone (PCAC) with ZnCl2 as an activation agent under microwave radiation was investigated. The activation step was performed at the microwave input power of 400 W and radiation time of 5 min. The properties of activated carbon were characterized by N2 adsorption Brunauer-Emmett-Teller (BET), scanning electron microscopy and Fourier transform infrared spectroscopy. Results showed that the BET surface area, Langmuir surface area, and total pore volume of PCAC were 939, 1,486 m(2)/g and 0.172 cm(3) / g, respectively. Adsorption capacity was demonstrated by the iodine numbers. The adsorptive property of PCAC was tested using methylene blue dye. Equilibrium data was best fitted by the Langmuir isotherm model, showing a monolayer adsorption capacity of 60.97 mg/ g. The pseudo-first-and pseudosecond- order kinetic models were examined to evaluate the kinetic data, and the rate constants were calculated. Adsorption of the dyes followed pseudo-first order kinetics. Thermodynamic parameters such as free energy, enthalpy and entropy of dye adsorption were obtained.