Energy Systems Engineering / Enerji Sistemleri Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4752
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Article Citation - WoS: 45Citation - Scopus: 31Highly Efficient Treatment of Petrochemical Spent Caustic Effluent Via Electro-Fenton Process for Cod and Toc Removal: Optimization and Experimental(Springer, 2023) Gholami, Asma; Mousavi, Seyed Borhan; Heris, Saeed Zeinali; Mohammadpourfard, MousaCaustic is commonly used in oil and gas refineries to remove CO2, H2S, organic sulfur, and acidic compounds; however, spent caustic must be treated considering the type of wastewater in refinery and petrochemical units due to their hazardous characteristics. This research aims to reduce the chemical oxygen demand (COD) and the total organic carbon (TOC) from the used caustic effluent of the olefin unit of Ilam Petrochemical Company employing the electro-Fenton method. The affecting parameters, such as H2O2 concentration, reaction time, pH, and current density on the COD and TOC removal rate, were investigated. An experimental design by response surface methodology (RSM) based on the Box–Behnken method with the considered factors was considered to study the setup’s effectiveness and optimize the conditions. The outcomes revealed that by increasing the H2O2 concentration from 11 to 18 mgL, the COD removal efficiency was enhanced from 68 to 93%. On the other hand, by increasing the reaction time after 15 min, the COD and TOC removal efficiency decreased. The same trend was observed by increasing the current density after the optimal value. The optimal conditions were acquired at pH = 4, current density = 20 mAcm2, H2O2 concentration = 18 mgL, and reaction time = 15 min. The promising results confirmed that the electro-Fenton could be an excellent treatment technique in Ilam Petrochemical Unit as a spent caustic treatment. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Article Citation - WoS: 9Citation - Scopus: 11Experimental Investigation of Spray Characteristics of Ethyl Esters in a Constant Volume Chamber(Springer, 2022) Ulu, Anılcan; Yıldız, Güray; Özkol, Ünver; Rodriguez, Alvaro DiezAbstract: Biodiesels are mainly produced via the utilization of methanol in transesterification, which is the widespread biodiesel production process. The majority of this methanol is currently obtained from fossil resources, i.e. coal and natural gas. However, in contrast with methanol, biomass-based ethanol can also be used to produce biodiesels; this could allow the production line to become fully renewable. This study aimed to investigate the spray characteristics of various ethyl ester type biodiesels derived from sunflower and corn oils in comparison to methyl esters based on the same feedstocks and reference petroleum-based diesel. Spray penetration length (SPL) and spray cone angle (SCA) were experimentally evaluated in a constant volume chamber allowing optical access, under chamber pressures of 0, 5, 10 and 15 bar and injection pressures of 600 and 800 bar. Sauter mean diameter (SMD) values were estimated by using an analytical correlation. Consequently, ethyl esters performed longer SPL (2.8–20%) and narrower SCA (5.1–19%) than diesel under ambient pressures of 5 and 10 bar. Although the SMD values of ethyl esters were 48% higher than diesel on average, their macroscopic spray characteristics were very similar to those of diesel under 15 bar chamber pressure. Moreover, ethyl esters were found to be very similar to methyl esters in terms of spray characteristics. The differences in SPL, SCA and SMD values for both types of biodiesels were lower than 4%. When considering the uncertainty (± 0.84%) and repeatability (±5%) ratios, the difference between the spray characteristics of methyl and ethyl esters was not major.