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Öğe Co-processing of olive bagasse with crude rapeseed oil via pyrolysis(Sage Publications Ltd, 2017) Ucar, Suat; Karagoz, SelhanThe co-pyrolysis of olive bagasse with crude rapeseed oil at different blend ratios was investigated at 500oC in a fixed bed reactor. The effect of olive bagasse to crude rapeseed oil ratio on the product distributions and properties of the pyrolysis products were comparatively investigated. The addition of crude rapeseed oil into olive bagasse in the co-pyrolysis led to formation of upgraded biofuels in terms of liquid yields and properties. While the pyrolysis of olive bagasse produced a liquid yield of 52.5 wt %, the highest liquid yield of 73.5 wt % was obtained from the co-pyrolysis of olive bagasse with crude rapeseed oil at a blend ratio of 1:4. The bio-oil derived from olive bagasse contained 5% naphtha, 10% heavy naphtha, 30% gas oil, and 55% heavy gas oil. In the case of bio-oil obtained from the co-pyrolysis of olive bagasse with crude rapeseed oil at a blend ratio of 1:4, the light naphtha, heavy naphtha, and light gas oil content increased. This is an indication of the improved characteristics of the bio-oil obtained from the co-processing. The heating value of bio-oil from the pyrolysis of olive bagasse alone was 34.6 MJ kg(-1) and the heating values of bio-oils obtained from the co-pyrolysis of olive bagasse with crude rapeseed oil ranged from 37.6 to 41.6 MJ kg(-1). It was demonstrated that the co-processing of waste biomass with crude plant oil is a good alternative to improve bio-oil yields and properties.Öğe Co-pyrolysis of pine nut shells with scrap tires(Elsevier Sci Ltd, 2014) Ucar, Suat; Karagoz, SelhanThe co-pyrolysis of pine nut shells (PNS) with scrap tires (ST) at different blend ratios was carried out at 500 degrees C. The addition of ST into PNS in the co-pyrolysis process not only increased bio-oil yields but also improved bio-oil characteristics when compared with the pyrolysis of PNS. The carbon content in bio-oils from all PNS/ST blend ratios was higher and oxygen content was lower than that of PNS-derived oil. This is an indication of the improved characteristics of bio-oils from the co-pyrolysis of biomass with scrap tires. The blend ratio in the feedstock of co-pyrolysis had a significant effect on the product distributions and physico-chemical properties of bio-oils. When heating values of bio-oils produced from the pyrolysis of PNS were compared with bio-oils obtained from the co-pyrolysis of PNS with ST, the addition of ST into PNS led to increase heating values of bio-oils with the exception of PNS/ST (4:1)-derived bio-oil. In addition, the heating values of gas products and levels of hydrogen and hydrocarbons (from C-1 to C-4) in the gas products from the co-pyrolysis of PNS/ST blends were higher than that of the pyrolysis of PNS. The heating values of chars produced from the co-pyrolysis of PNS/ST blends were found to be in the range of 31.1 and 32.9 MJ kg (1). (C) 2014 Elsevier Ltd. All rights reserved.Öğe Co-pyrolysis of waste polyolefins with waste motor oil(Elsevier Science Bv, 2016) Ucar, Suat; Ozkan, Ahmet R.; Karagoz, SelhanThe co-pyrolysis of waste polyolefins [waste polyethylene (PE) and waste polypropylene (PP)] with waste motor oil (WMO) was performed at different ratios under a nitrogen atmosphere at 500 degrees C. The effects of WMO on the pyrolysis of waste polyolefins and their blends were investigated under identical conditions. The addition of WMO into waste polyolefins not only increased the liquid yields but also improved the properties of liquid products. In the most cases, the co-pyrolysis process had a positive synergistic effect on the liquid yields when compared with the calculated co-pyrolysis yields. The naphtha and paraffinic contents of the liquid products obtained from the co-pyrolysis of PE/WMO, PE/PP/WMO blends were higher than liquid products obtained from the pyrolysis of the individual waste polyolefins. The trace elements as well as heavy metals in the liquid products from the pyrolysis of WMO alone or the co-pyrolysis of waste polyolefins with WMO were observed to be lower than the WMO feed. The prominent gas products obtained from the pyrolysis of individual waste polyolefins and WMO or the co-pyrolysis of waste polyolefins/WMO blends were hydrocarbons and hydrogen. The heating values of the pyrolysis and co-pyrolysis gases were found to be in the range of 27.6-32.4 MJ Nm(-3). (C) 2016 Elsevier B.V. All rights reserved.Öğe Comparative studies of hydrochars and biochars produced from lignocellulosic biomass via hydrothermal carbonization, torrefaction and pyrolysis(Elsevier Sci Ltd, 2023) Ercan, Betul; Alper, Koray; Ucar, Suat; Karagoz, SelhanIn this study, hydrothermal carbonization, torrefaction, and pyrolysis of hornbeam wood chips were performed. Different runs were conducted at varying temperatures ranging from 225 to 575 & DEG;C, and the resulting biochars and hydrochars were analyzed. Biochars obtained from torrefaction runs had high yields, but no significant structural changes compared to raw material. Biochars produced from pyrolysis runs had high fixed carbon content that increased with temperature. Hydrochars obtained from hydrothermal carbonization had higher degree of carbonization than biochars produced from torrefaction under identical conditions. The order of carbonization degree, from highest to lowest, was: biochars obtained from the pyrolysis process, hydrochars produced from the hydrothermal carbonization process, and biochars obtained from the torrefaction process. The highest heating value of the biochar was 32.51 MJ kg-1, produced from the pyrolysis run at 575 & DEG;C.Öğe Effect of a water-tolerant Lewis acid catalyst on the yields and properties of hydrochars from hydrothermal carbonization of walnut wood(Springer, 2023) Ercan, Betul; Ajagbe, Yusuf O.; Ucar, Suat; Tekin, Kubilay; Karagoz, SelhanThe hydrothermal carbonization of walnut wood chips was conducted at 200-250 & DEG;C for 1-8 h. Increasing the hydrothermal carbonization temperature or the residence time decreased the volatile products and increased the fixed carbon content of the hydrochars. The hydrochars produced from the non-catalytic experiments at 250 & DEG;C for 6 and 8 h were in the lignite class. The lowest O/C and H/C atomic ratios were obtained after carbonization at 250 & DEG;C for 8 h. The catalytic hydrothermal carbonization experiments were carried out in the absence and presence of InCl3 using 1, 2, and 4 mmol of InCl3 at 200, 225, and 250 & DEG;C for 4 h. The highest heating value of hydrochar from the catalytic experiment was 24.73 MJ/kg and was obtained at 250 & DEG;C for 4 h using 1 mmol InCl3. Process water reuse resulted in increased heating values of the hydrochars in both the non-catalytic and catalytic experiments. The use of InCl3 promoted the coalification degree of the hydrochars. These results demonstrate that InCl3 is a suitable catalyst for producing hydrochars via the hydrothermal carbonization of walnut wood chips, which can be used as a solid biofuel.Öğe Effects of Metal Chlorides on the Hydrothermal Carbonization of Grape Seeds(Amer Chemical Soc, 2021) Hasan, Rebaz O.; Ercan, Betul; Acikkapi, Ayse N.; Ucar, Suat; Karagoz, SelhanIn this study, hydrothermal carbonization (HTC) of grape seeds, a lignocellulosic biomass, was carried out at various temperatures (200, 225, and 250 degrees C), different reaction times (6, 12, and 24 h), and different biomass:water ratios (0.025, 0.05, and 0.1). The most important parameter affecting the yields and characteristics of hydrochars was found to be temperature. The HTC of grape seeds was then conducted in the presence of metal chlorides (i.e., CsCl, ZnCl2, and SnCl2) at temperatures of 200, 225, and 250 degrees C for 12 h. SnCl2 behaved very differently in the HTC process than the other catalysts (or no catalyst). A major difference among these catalysts was the extent to which they were incorporated within the hydrochar structure. SnCl2 was much more readily incorporated than was CsCI or ZnCl2. Carbon microspheres were observed in hydrochars from obtained biomass without a catalyst and with CsCl and ZnCl2 catalysts; agglomerated carbon nanospheres were observed in hydrochars produced with SnCl2. Hydrochars obtained at 225 and 250 degrees C by using SnCl2 and ZnCl2 catalysts were in the lignite class, while hydrochars obtained from biomass without a catalyst, and using CsCI, were in the peat coal class.Öğe Hydrothermal carbonization of lignocellulosic biomass and effects of combined Lewis and Bronsted acid catalysts(Elsevier Sci Ltd, 2020) Evcil, Tolgahan; Simsir, Hamza; Ucar, Suat; Tekin, Kubilay; Karagoz, SelhanThis study is the first to investigate the effect of combined Lewis and Bronsted acid catalysts on the hydrothermal carbonization of fir wood samples; here, hydrothermal carbonization of fir wood-with and without catalyst-was performed. In non-catalytic runs, the effects of temperature and residence time on hydrochar yields were investigated; temperature significantly affected hydrochar yields, whereas residence time had very little effect. A gradual increase in temperature resulted in a decrease in hydrochar yields while increasing the carbon content of hydrochars. At all tested temperatures, the use of a catalyst led to a decrease in hydrochar yields. The highest heating value of 29.12 MJ kg(-1) was obtained at the highest temperature (275 degrees C) and the longest residence time (24 h). The use of catalysts slightly decreased the heating values. The hydrochars were mainly in the class of lignite coal; hydrochar obtained at 275 degrees C and a residence time of 12 h-either with or without catalysts-was classified as bituminous coal. Irregular carbon sphere formation was observed at all temperatures tested in the catalytic runs; however, no carbon spheres were observed in the non-catalytic runs. XRD patterns of hydrochars from the non-catalytic runs were similar for temperatures of 225, 250 and 275 degrees C; the peak observed at 2 theta of 22 degrees broadened after HTC processing. In the catalytic runs, two new peaks at 2 theta of 38 degrees and 49 degrees were observed, in addition to broadened peaks (2 theta = 22 degrees). The use of catalysts led to the formation of the secondary char.Öğe Hydrothermal liquefaction of olive oil residues(Elsevier, 2021) Evcil, Tolgahan; Tekin, Kubilay; Ucar, Suat; Karagoz, SelhanHydrothermal liquefaction (HTL) of olive oil residues was conducted at various temperatures (250, 270, 300 and 330 degrees C) and residence times (5, 15, 30, and 60 min). The effect of metal chlorides (AlCl3 and SnCl2) on product yields and compositions was investigated under optimum conditions (300 degrees C for 15 min). Bio-oil and solid residue yields from the non-catalytic run were 30.8 and 31.8 wt%, respectively. Use of metal chlorides led to decreased bio-oil yields and increased solid residue yields. Experiments were also carried out using methanol, with and without catalysts, and under identical conditions. The bio-oil yield from the non-catalytic supercritical methanol liquefaction (SCMEL) was 33.5 wt%, increasing to 40.3 wt% with AlCl3, however, SnCl2 had almost no effect on bio-oil yield. The heating values of bio-oils from HTL runs were higher than those of corresponding SCMEL runs, and the highest heating value of bio-oil (34 MJ/kg) was obtained with AlCl3. Phenols and ketones were major bio-oil constituents in the HTL runs, whereas esters were the most abundant compounds in bio-oils from SCMEL runs.Öğe Influence of Co-Pyrolysis of Waste Tetra Pak with Waste Motor Oil on Product Distribution and Properties for Fuel Application(Amer Chemical Soc, 2019) Tekin, Kubilay; Ucar, Suat; Karagoz, SelhanIn this work, waste tetra pak (WTP) and waste motor oil (WMO), with different blend ratios of WTP/WMO (4:1, 2:1, 1:1, 1:2, 1:4) were subjected to co-pyrolysis at 500 degrees C. For the purpose of comparison, individual pyrolysis of WTP and WMO was conducted under identical conditions. Pyrolysis/co-pyrolysis products were collected as liquids (containing an oil phase and an aqueous phase), solid residue, and gaseous products. The highest oil yield was 72.14 wt % and was obtained at a blend ratio of 1:4 (WTP/WMO). Synergistic effects on oil yields were observed in all blends. Heating values of the oils from blends ranged from 45.2 to 46.1 MJ kg(-1). The heating value of the gas product obtained from the co-pyrolysis of WTP with WMO at a blend ratio of 1:1 (WTP/WMO) was 24.5 MJ Nm(-3). Heating values of the solid residue ranged from 24.2 to 26.7 MJ kg(-1), comparable to that of sub-bituminous coal. These results suggest that WTP could be co-pyrolyzed with WMO to produce liquid, solid, and gaseous fuels.Öğe Preparation and characterization of activated carbon produced from pomegranate seeds by ZnCl2 activation(Elsevier Science Bv, 2009) Ucar, Suat; Erdem, Murat; Tay, Turgay; Karagoz, SelhanIn this study, pomegranate seeds, a by-product of fruit juice industry, were used as precursor for the preparation of activated carbon by chemical activation with ZnCl2. The influence of process variables such as the carbonization temperature and the impregnation ratio on textural and chemical-surface properties of the activated carbons was studied. When using the 2.0 impregnation ratio at the carbonization temperature of 600 degrees C, the specific surface area of the resultant carbon is as high as 978.8 m(2) g (1). The results showed that the surface area and total pore volume of the activated carbons at the lowest impregnation ratio and the carbonization temperature were achieved as high as 709.4 m(2) g (1) and 0.329 cm(3) g (1). The surface area was strongly influenced by the impregnation ratio of activation reagent and the subsequent carbonization temperature. (C) 2009 Elsevier B.V. All rights reserved.Öğe Production of Hydrochars from Lignocellulosic Biomass with and without Boric Acid(Wiley-V C H Verlag Gmbh, 2022) Ercan, Betul; Ajagbe, Yusuf O.; Ucar, Suat; Tekin, Kubilay; Karagoz, SelhanHydrothermal carbonization (HTC) is an important thermochemical process where biomass is converted into coal-like solid products known as hydrochars. The HTC process is performed in hot-compressed water under self-generated pressures. In this work, the HTC of acorn shells was conducted at various temperatures and reaction times with and without boric acid (H3BO3). A high degree of carbonization occurred at 250 degrees C in non-catalytic and catalytic 4-h runs. Hydrochars obtained from non-catalytic and catalytic runs at 250 degrees C consisted of spherically carbon particles with diameters ranging from 303 nm to 3.27 mu m. Carbon spheres at 200 and 225 degrees C for 2 h were not observed. The yield and carbon content of the hydrochars were slightly increased by reuse of the process water in thermal runs without catalysts.Öğe Removal of lead (II) and nickel (II) ions from aqueous solution using activated carbon prepared from rapeseed oil cake by Na2CO3 activation(Springer, 2015) Ucar, Suat; Erdem, Murat; Tay, Turgay; Karagoz, SelhanIn this study, rapeseed oil cake as a precursor was used to prepare activated carbons by chemical activation with sodium carbonate (Na2CO3) at 600 and 800 A degrees C. The activated carbon with the highest surface area of 850 m(2) g(-1) was produced at 800 A degrees C. The prepared activated carbons were mainly microporous. The activated carbon having the highest surface area was used as an adsorbent for the removal of lead (II) and nickel (II) ions from aqueous solutions. The effects of pH, contact time, and initial ion concentration on the adsorption capacity of the activated carbon were investigated. The kinetic data of adsorption process were studied using pseudo-first-order, pseudo-second-order kinetic models and intraparticle diffusion model. The experimental data were well adapted to the pseudo-second-order model for both tested ions. The adsorption data for both ions were well correlated with Langmuir isotherm. The maximum monolayer adsorption capacities of the activated carbon for the removal of lead (II) and nickel (II) ions were determined as 129.87 and 133.33 mg g(-1), respectively.Öğe Removal of Lead (II) Ions from Aqueous Solutions onto Activated Carbon Derived from Waste Biomass(Hindawi Publishing Corporation, 2013) Erdem, Murat; Ucar, Suat; Karagoz, Selhan; Tay, TurgayThe removal of lead (II) ions from aqueous solutions was carried out using an activated carbon prepared from a waste biomass. The effects of various parameters such as pH, contact time, initial concentration of lead (II) ions, and temperature on the adsorption process were investigated. Energy Dispersive X-Ray Spectroscopy (EDS) analysis after adsorption reveals the accumulation of lead (II) ions onto activated carbon. The Langmuir and Freundlich isotherm models were applied to analyze equilibrium data. The maximum monolayer adsorption capacity of activated carbon was found to be 476.2 mg g(-1). The kinetic data were evaluated and the pseudo-second-order equation provided the best correlation. Thermodynamic parameters suggest that the adsorption process is endothermic and spontaneous.Öğe The slow pyrolysis of pomegranate seeds: The effect of temperature on the product yields and bio-oil properties(Elsevier, 2009) Ucar, Suat; Karagoz, SelhanThe slow pyrolysis of pomegranate seeds was carried out at 400, 500, 600 and 800 degrees C. The effect of temperature on the product distribution was discussed. The maximum liquid yields were obtained at the temperatures of 500 and 600 degrees C. The gaseous products from the pyrolysis of pomegranate seeds contained CO2, CO, CH4 as well as hydrocarbons from C-2 to C-7 and H2S. The major gas product was CO2. Identification of bio-oil components was done by gas chromatography/mass spectrometry (GC-MS). Phenols and alkyl-benzenes were prominent in bio-oils obtained at all tested temperatures. The boiling point distributions of hydrocarbons in bio-oils at 400, 500, 600 and 800 degrees C were found to be similar. The total non-aromatic hydrocarbons were higher than that of aromatic hydrocarbons in water fractions for all pyrolysis temperatures. Bio-chars produced from pomegranate seeds are carbon rich fuels with high bulk densities and calorific values. (c) 2009 Elsevier B.V. All rights reserved.Öğe Sulfonic Acid-Catalyzed Biocoal Production from Lignocellulosic Biomass(Amer Chemical Soc, 2024) Alper, Koray; Auersvald, Milos; Kejla, Lukas; Ercan, Betul; Ucar, Suat; Tekin, Kubilay; Simacek, PavelIn this study, hydrothermal carbonization (HTC) of spruce wood was studied at different temperatures (200-260 degrees C) and residence times (2-48 h). An increase in the temperature and residence time resulted in higher heating values of hydrochars. The effect of temperature on the hydrochar yield and carbon content was more pronounced than the residence time. Two sulfonic acid catalysts were explored for the first time in the HTC of spruce wood at 240 degrees C for 24 h. The impact of sulfonic acid type and concentration on hydrochar yields and characteristics was investigated. Among the tested acids, methanesulfonic acid (MSA) had a significant effect on HTC, producing hydrochar with increased fixed carbon content and a higher heating value compared to noncatalytic runs and runs with dodecyl benzenesulfonic acid (DBSA) under identical conditions. The highest fuel ratio obtained was 1.47 with MSA at a concentration of 0.01 M. A detailed quantitative analysis of the aqueous phase from HTC processing using gas chromatography helped to elucidate the differences between the tested acids and demonstrated promoted lignin depolymerization with increasing MSA concentration. The use of sulfonic acid significantly increased the yield of levulinic acid in the aqueous phase. Overall, these findings highlight the potential of sulfonic acid catalysts in enhancing the efficiency and product quality of HTC processes, providing insights into optimizing biomass conversion for sustainable energy production and biocoal synthesis.
