Browsing by Author "Turkyilmaz, A."

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Adsorption effectiveness and properties of an enriched activated carbon from residual biomass materials for non-polar benzene in gaseous environment
(2024.01.01) Isinkaralar, K.; Turkyilmaz, A.; Hosseini-Bandegharaei, A.; Prakash, C.
During the last century, benzene (C6H6) has been a highly studied substance, with some acute and chronic exposures leading directly to hematologic effects detected in humans. This work reports on preparing and examining biomass-derived activated carbons (HPACs) featuring high benzene adsorptive capacity. The fundamental goal of this paper is to propose a green approach for generating HPACs from Heracleum platytaenium Boiss. (Cow parsnip) as woody biomass using a low-cost approach. The characterization showed that chemical activation elicits more enhanced mesoporous structure, a higher degree of graphitization, and bulk porous structure with higher specific surface area and pore volume. To minimize the use of chemicals in the manufacture of high-performance HPACs, an essential pre-pyrolysis step was implemented prior to the chemical activation of biomass by NaOH. The samples were carbonized at different temperatures (500-900 degrees C) and named as HPAC500, HPAC600, HPAC700, HPAC800, and HPAC900. Considering micropore volume and total surface area, HPAC600 was superior, and maximum benzene adsorption capacities were: HPAC600 (127 mg/g) > HPAC700 (117 mg/g) > HPAC800 (101 mg/g) > HPAC500 (80 mg/g) > HPAC900 (59 mg/g) at selected conditions. Freundlich, Langmuir, and pseudo-first-order (PFO) and pseudo-second-order (PSO) models were used to mathematically describe HPAC600-vapor benzene sorption on HPAC600. The kinetic findings fitted PFO with optimal values of R-2 = 0.999, and the isotherm model adsorption fitted Freundlich model (R-2 = 1.000). The finding revealed that H. platytaenium is a useful material for producing adsorbents, and successful testing outcomes demonstrate that H. platytaenium products serve as a suitable benzene absorbent.
Production, characterization, and hydrogen storage properties of activated carbon from horse chestnut shell
(Elsevier B.V., 2024) Turkyilmaz, A.; Isinkaralar, K.; Dogan, M.; Kocer, K.B.; Bicil, Z.
With the increasing energy demand and the increase in carbon emissions from using fossil fuels, the demand for using renewable energy is increasing daily. Therefore, research on hydrogen storage, the biggest problem in using hydrogen energy, is significant. In this concept, a surface area of 2270 m2/g obtained with activated carbons obtained from the pyrolysis of horse chestnut shell with ZnCl2 at 600 °C, and the micropore volume of the same sample found to be 0.93 cc/g. Hydrogen storage at cryogenic temperature found to be 4.46% by weight. At room temperature, increased H2 storage was observed with increasing pressure and found to be 0.44% at 30 bar. According to thermogravimetric results, the residue amounts of activated carbons at 900 °C which synthesized at different agent ratios and carbonization temperatures varied between 76% and 83.3% respectively. Elemental analysis showed that the C% increase was linear with the increased surface area of the activated carbons obtained. According to infrared spectrum, the cellulosic structure of the samples pyrolyzed at 800 °C was wholly destroyed according to the results obtained; the micropore volume and surface area of the adsorbent are significant in hydrogen storage. Moreover, activated carbons are more environmentally friendly and essential in hydrogen storage than other adsorbents.