Chemical Engineering / Kimya Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/14

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  • Article
    Citation - WoS: 11
    Citation - Scopus: 12
    Treatment of Sugar Industry Wastewater by Using Subcritical Water as a Reaction Media
    (Wiley, 2023) Orak, Ceren; Öcal, Bulutcem; Yüksel, Aslı
    The sugar industry is one of the most wastewater-producing industries and it contains high content of organic and inorganic substances. Treating and reusing wastewater has significant importance because sugar industry needs to use a high volume of water. In this study, sugar industry wastewater was treated under subcritical conditions and the impacts of reaction temperature and duration over TOC removal percentage were investigated. Additionally, the impact of NaOH concentration over TOC removal percentage was examined. The highest TOC removal was obtained almost 95 % in the presence of 0.1 M of NaOH at 240 degrees C for 90 min of reaction duration. Treatment of sugar industry wastewater by subcritical water oxidation followed the second-order reaction kinetic model and the activation energy was found as 11.41 kJ/mol. Furthermore, the intermediate products were identified via GC-MS.
  • Article
    Citation - WoS: 21
    Citation - Scopus: 21
    Graphene-Supported Lafeo3 for Photocatalytic Hydrogen Energy Production
    (Wiley, 2021) Orak, Ceren; Yüksel, Aslı
    Hydrogen is a green, environmentally benign and sustainable energy source with no harmful combustion products to fulfil the increasing energy demand. Photocatalytic oxidation has various advantageous to produce hydrogen from different sources such as wastewater, alcohol solutions using different types of catalysts. Sucrose solution was chosen as a model solution to evolve hydrogen using LFO and GLFO catalysts under solar light irradiation, and graphene was used as a catalyst support to enhance the amount of produced hydrogen amount. A characterization study, which consists of SEM-EDX, BET, XRD, PL, TEM, XPS and FT-IR analyses, was carried out. A full factorial design was created via Minitab 18 to analyse the factors affecting the produced hydrogen amount, which are pH, catalyst loading, H2O2 concentration and graphene content statistically. Based on the results, graphene content is an important parameter and pH and H2O2 concentration have a synergetic effect over hydrogen production. Additionally, the effects of calcination temperature, pH, H2O2 concentration and catalyst loading over produced gases were investigated. The best promising result was obtained as 3388 mu mol/g(cat) at the following reaction conditions: 7.5 of pH, 0.1 g L-1 catalyst loading (GLFO, which is calcined at 700 degrees C) and using 15 mM H2O2 under solar light irradiation. Novelty Statement Hydrogen is produced from sucrose solution with low cost process requiring no special equipment, high pressure or temperature. First study that uses perovskite catalysts for the production of hydrogen from sucrose solution by photo-Fenton like oxidation GLFO is a promising photocatalyst for H-2 production by solar-Fenton like oxidation with the highest H-2 evaluation at 3388.34 mu mol/g(cat).