GCRIS Repository Collection: Collection of Chemical Engineering / Kimya Mühendisliği Bölümü koleksiyonu
Collection of Chemical Engineering / Kimya Mühendisliği Bölümü koleksiyonu
https://hdl.handle.net/11147/14
2024-03-28T15:12:56Z
2024-03-28T15:12:56Z
Mini modular plant design for ethylene production using Martian atmosphere on Mars
Deliismail, Özgün
Şeker, Erol
https://hdl.handle.net/11147/14275
2024-03-13T07:39:30Z
2024-01-01T00:00:00Z
Title: Mini modular plant design for ethylene production using Martian atmosphere on Mars
Authors: Deliismail, Özgün; Şeker, Erol
Abstract: A main shift in the competitive landscape of technology development is in 3D printing of complex articles made of variety of materials due to faster manufacturing and less human error in the production. In fact, it seems to be a viable candidate for the construction of structures for terrestrial and extraterrestrial life in future. Thus, new or damaged equipment in space explorations could be replaced instantly, and habitats could be manufactured using 3D printing in varying gravitational fields in the solar system. Among 3D printing materials, HDPE is commonly used in the projects, such as a prototype manufacturing or pipes or damp-proof membrane. This study initially focused on the preliminary design of the self-sustaining mini ethylene production plant from Martian atmosphere with scale-out architecture. UniSIM® was integrated with MATLAB® via CAPE-OPEN extension to design mini-ethylene production plant at low gravity. Ethylene capacity was found as 17.71 tons/year for 100 modules. © 2023 COSPAR
2024-01-01T00:00:00Z
Simultaneous topology design and optimization of PDE constrained processes based on mixed integer formulations
Ertürk, Emrullah
Deliismail, Özgün
Şıldır, Hasan
https://hdl.handle.net/11147/14272
2024-02-15T12:22:44Z
2024-01-01T00:00:00Z
Title: Simultaneous topology design and optimization of PDE constrained processes based on mixed integer formulations
Authors: Ertürk, Emrullah; Deliismail, Özgün; Şıldır, Hasan
Abstract: Simultaneous topological design and optimization of complex processes that are described by partial differential equations is a challenging but promising research area. Widely adopted nested and sequential approaches are mostly applicable based on heuristic solutions, hindering the theoretical improvement potential due to decentralized decision-making in subsequent stages with a significant number of trial-and-error procedures. This study introduces a mixed integer formulation addressing the governing equations and case-dependent topological constraints at each discretization point, enabling solutions through rigorous solvers under process-related constraints and objectives. Nonlinear expressions in the formulations are further tailored using piecewise linear approximations, still representing the major nonlinear trends through a mixed-integer linear nature to favor global optimality and benefit from computational advancements, when needed. Heat and Stokes flow problems are used as case studies to demonstrate the applicability of the methodology. © 2024 Elsevier B.V.
2024-01-01T00:00:00Z
Breakthrough curve analysis of phosphorylated hazelnut shell waste in column operation for continuous harvesting of lithium from water
Recepoğlu, Yaşar Kemal
Arar, Özgüer
Yüksel, Aslı
https://hdl.handle.net/11147/14130
2024-01-22T12:52:52Z
2024-01-01T00:00:00Z
Title: Breakthrough curve analysis of phosphorylated hazelnut shell waste in column operation for continuous harvesting of lithium from water
Authors: Recepoğlu, Yaşar Kemal; Arar, Özgüer; Yüksel, Aslı
Abstract: In batch-scale operations, biosorption employing phosphorylated hazelnut shell waste (FHS) revealed excellent lithium removal and recovery efficiency. Scaling up and implementing packed bed column systems necessitates further design and performance optimization. Lithium biosorption via FHS was investigated utilizing a continuous-flow packed-bed column operated under various flow rates and bed heights to remove Li to ultra-low levels and recover it. The Li biosorption capacity of the FHS column was unaffected by the bed height, however, when the flow rate was increased, the capacity of the FHS column decreased. The breakthrough time, exhaustion time, and uptake capacity of the column bed increased with increasing column bed height, whereas they decreased with increasing influent flow rate. At flow rates of 0.25, 0.5, and 1.0 mL/min, bed volumes (BVs, mL solution/mL biosorbent) at the breakthrough point were found to be 477, 369, and 347, respectively, with the required BVs for total saturation point of 941, 911, and 829, while the total capacity was calculated as 22.29, 20.07, and 17.69 mg Li/g sorbent. In the 1.0, 1.5, and 2.0 cm height columns filled with FHS, the breakthrough times were 282, 366, and 433 min, respectively, whereas the periods required for saturation were 781, 897, and 1033 min. The three conventional breakthrough models of the Thomas, Yoon-Nelson, and Modified Dose-Response (MDR) were used to properly estimate the whole breakthrough behavior of the FHS column and the characteristic model parameters. Li's extremely favorable separation utilizing FHS was evidenced by the steep S-shape of the breakthrough curves for both parameters flow rate and bed height. The reusability of FHS was demonstrated by operating the packed bed column in multi-cycle mode, with no appreciable loss in column performance.
2024-01-01T00:00:00Z
Atomic-scale insights into carbon dioxide hydrogenation over bimetallic iron-cobalt catalysts: A density functional theory study
Tuncer, Dilan
Kızılkaya, Ali Can
https://hdl.handle.net/11147/14111
2024-01-22T07:55:58Z
2023-01-01T00:00:00Z
Title: Atomic-scale insights into carbon dioxide hydrogenation over bimetallic iron-cobalt catalysts: A density functional theory study
Authors: Tuncer, Dilan; Kızılkaya, Ali Can
Abstract: The conversion of carbon dioxide to fuels and chemicals is a promising long-term approach for mitigating CO2 emissions. Despite extensive experimental efforts, a fundamental understanding of the bimetallic catalytic structures that selectively produce the desired products is still lacking. Here, we report on a computational surface science approach into the effect of the Fe doping of Co(111) surfaces in relation to CO2 hydrogenation to C1 products. Our results indicate that Fe doping increases the binding strength of surface species but slightly decreases the overall catalytic activity due to an increase in the rate-limiting step of CO dissociation. FeCo(111) surfaces hinder hydrogenation reactions due to lower H coverages and higher activation energies. These effects are linked to the Lewis basic character of the Fe atoms in FeCo(111), leading to an increased charge on the adsorbates. The main effect of Fe doping is identified as the inhibition of oxygen removal from cobalt surfaces, which can be expected to lead to the formation of oxidic phases on bimetallic FeCo catalysts. Overall, our study provides comprehensive mechanistic insights related to the effect of Fe doping on the catalytic behavior and structural evolution of FeCo bimetallic catalysts, which can contribute to the rational design of bimetallic catalysts.
2023-01-01T00:00:00Z