Browsing by Author "Deniz İ."

Now showing 1 - 4 of 4
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    Lignin recovery from hazelnut shells
    (Turkiye Klinikleri, 2023) Gezen Ö.; Filizfidanoğlu A.; Özgener Ç.; Deniz İ.
    The main goal of this work was to study alkaline pretreatment of hazelnut shells (HSs) by utilization of NaOH and Ca(OH)2 with or without glycerol. The highest lignin recovery was obtained for NaOH-glycerol-pretreated HSs. This research also determined the efficiency of enzymatic hydrolysis where xylanase and cellulase were added to the pretreated residue. The highest amount of lignin of 63.2% was achieved when NaOH was used with glycerol in the pretreatment process. These findings revealed that the NaOH-catalyzed glycerol pretreatment applied in this study has great capability to be used in industrial applications. © TÜBİTAK.
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    Effect of an algae integrated water wall on energy consumption and CO2 emission
    (Inderscience Publishers, 2023) Altunacar N.; Ezan M.A.; Yaman Y.; Tokuç A.; Budakoğlu B.; Köktürk G.; Deniz İ.
    This study develops a transient thermal model for an indoor in which a photobioreactor (PBR) is integrated into one of its facades. Thermal comfort, energy consumption, and carbon dioxide (CO2) emissions were interpreted in different design scenarios for Izmir, Turkey. As a result, it was determined that a 20% window-to-wall ratio (WWR) provides the most comfortable results, and the algae usage increases the annual comfort by 19% and reduces the heating/cooling demand. Compared to a water wall, it provides a 17% reduction in energy consumption and CO2 emissions. Copyright © 2023 Inderscience Enterprises Ltd.
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    Effect of Different Parameters on Enzymatic Hydrolysis of Hazelnut Shells
    (Sakarya University, 2024) Gezen Ö.; Deniz İ.
    In the last few decades, the increasing levels of environmental pollution have prompted a shift towards alternative energy sources and biobased solutions, such as lignocellulosic biomass. Lignocellulosic biomass (LB) is primarily derived from plants and is composed mainly of polysaccharides, namely cellulose, hemicellulose, and the aromatic polymer lignin. Hazelnut shells (HS), with a high lignin content of 43%, hemicellulose of 30%, and cellulose of 26%, hold promise as a valuable source of LB. In order to process those LB, lignin and hemicellulose are separated using various treatment methods. However, instead of being used solely for combustion, lignin-containing materials can be valorized for a range of purposes, from biomedical applications to the energy sector. In this study, the enzymatic hydrolysis of HS was conducted over different time periods (24, 48, 72, and 96 hours), at different temperature values with varying enzyme concentrations (0.05, 0.1, and 0.25 mL of cellulase/xylanase enzyme cocktail). To enhance the enzymatic hydrolysis, an alkaline pretreatment method using sodium hydroxide (NaOH) was employed. The results demonstrate that the maximum sugar concentration was achieved at 50°C, after 72 hours, and with a cellulase/xylanase cocktail concentration of 0.1 mL. © 2024, Sakarya University. All rights reserved.
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    Photobioreactor facade panels: enhancing comfort, reducing energy use, and capturing carbon in temperate continental climates
    (Springer Nature, 2025) Yaman Y.; Tokuç A.; Deniz İ.; Ezan M.A.; Köktürk G.; Dalay M.C.; Demirel Z.
    Buildings contribute around 37% to global carbon emissions, prompting a growing interest in innovative carbon capture technologies. Among these, the integration of microalgae-based photosynthesis into building facades has emerged as a promising solution. This approach offers multiple benefits, including carbon sequestration, reduced energy consumption, dynamic shading, and improved thermal regulation. This paper investigates the impact of integrating photobioreactor (PBR) facade elements, specifically on the south-facing facade of an office building in a temperate continental climate. The study evaluates the system’s effects on indoor thermal and visual comfort, energy production, and carbon dioxide (CO2) sequestration for three distinct PBR facade alternatives and compares them with a commercial curtain wall. The continuous PBR system varies in performance depending on production intensity, necessitating an initial optimization for thermal and visual comfort alongside energy use. Simulations were conducted using Rhinoceros/Grasshopper plug-ins, with optimization performed via the Octopus tool. The results, focusing on the Chlorella vulgaris algae strain, demonstrate that all facade configurations achieve a daylight performance exceeding 50% and meet desired thermal comfort levels. Although the energy generated by the PBR facade does not fully offset the building’s energy consumption, annual CO2 sequestration ranges from 84.87 kg to 770.13 kg. This study concludes that microalgae facades offer a viable strategy for enhancing a building’s energy performance and reducing CO2 emissions, without compromising occupant comfort. Additionally, the findings provide valuable insights for designers, researchers, investors and stakeholders and provides a payback period of these systems (16–24 years) for commercialization in the building industry. © Jiangnan University 2024.