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carbon-dioxide
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Manufacturing and Evaluation of Carbon Dioxide Hydrogenation Reaction Catalyst for Methanol Production
, M.Sc. Thesis Sharif University of Technology ; Fotovat, Farzam (Supervisor) ; Zamaniyan, Akbar (Supervisor) ; Zamani, Yahya (Co-Supervisor) ; Rashidzadeh, Mehdi (Co-Supervisor)
Abstract
The hydrogenation of carbon dioxide to methanol represents a promising route for the efficient use of an anthropogenic greenhouse gas, in which catalysts play a key role in carbon dioxide conversion and methanol selectivity. In this study, firstly, CuO-ZnO-Al2O3, CuO-ZnO-ZrO2, CuO-ZnO-ZrO2-Al2O3, CuO-ZnO-Al2O3-CeO2 and CuO-ZnO-ZrO2-CeO2 catalysts were made using co-precipitation method, then these catalysts were characterized by inductively coupled plasma optical emission spectrometry, specific surface area and pore size distribution, X-ray diffraction, Field Emission Scanning Electron Microscopy, temperature programmed reduction. Finally, in order to compare the performance of the catalysts...
Solvation thermodynamics of hydroxyl and carbonyl group in supercritical CO2 by Monte Carlo simulations
, Article Chemical Physics Letters ; Volume 458, Issue 4-6 , 2008 , Pages 308-312 ; 00092614 (ISSN) ; Khanlarkhani, A ; Sharif University of Technology
2008
Abstract
The Helmholtz free energy of solvation (ΔslvA) of 2-propanol and acetone in supercritical CO2 were calculated by expanded-ensemble method. For both solute molecules, ΔslvA is well represented by the polynomial equation of the third power of density and the density value correspond to the maximum stability decreases with increasing temperature. In all states under study acetone is more stable than 2-propanol. At low densities the solvation of acetone is more exothermic than 2-propanol while at high densities it come with less entropic penalty. The solvent reorganization energy is more favorable in 2-propanol case, although the role of solute-solvent interactions is dominant in both cases. ©...
Study of self-association of water in supercritical CO2 by Monte Carlo simulation: Does water have a specific interaction with CO2?
, Article Fluid Phase Equilibria ; Volume 267, Issue 2 , 2008 , Pages 181-187 ; 03783812 (ISSN) ; Khanlarkhani, A ; Sharif University of Technology
2008
Abstract
The extent of the self-association of water in supercritical CO2 has been investigated in a wide range of density and temperature by the test particle insertion technique. The results show that the association constant for water decreases with temperature and weakly depends on CO2 density. This weak density dependence provides evidence for the lack of a strong specific CO2-water interaction. Comparing calculated association constants with its gas-phase values shows that the association constant is at most ca. 38% lower than its gas-phase value in the high density-low temperature region. Inspection of the simulated radial distribution functions revealed that forming modest water-CO2 complexes...
Probabilistic optimization of networked multi-carrier microgrids to enhance resilience leveraging demand response programs
, Article Sustainability (Switzerland) ; Volume 13, Issue 11 , 2021 ; 20711050 (ISSN) ; Amir, V ; Habibifar, R ; Golmohamadi, H ; Sharif University of Technology
MDPI AG
2021
Abstract
Microgrids have emerged as a practical solution to improve the power system resilience against unpredicted failures and power outages. Microgrids offer substantial benefits for customers through the local supply of domestic demands as well as reducing curtailment during possible disruptions. Furthermore, the interdependency of natural gas and power networks is a key factor in energy systems’ resilience during critical hours. This paper suggests a probabilistic optimization of networked multi-carrier microgrids (NMCMG), addressing the uncertainties associated with thermal and electrical demands, renewable power generation, and the electricity market. The approach aims to minimize the NMCMG...
Process Analysis of Oxy Fuel in Power Plant Using Membrane to Separate Oxygen
, M.Sc. Thesis Sharif University of Technology ; Soltanieh, Mohammaad (Supervisor) ; Goodarznia, Iraj (Co-Advisor)
Abstract
Considering the drastical increasing of greenhouse gases in the atmosphere, especially carbon dioxide, reduction of these gases seems necessary to combat global warming. Fossil fuel power plants are one of the main sources of CO2 emission. In this thesis, CO2 capture from a natural gas fired combined cycle power plant using different oxygen percent in air feed is studied. Aspen Plus was used to evaluate the effect of this capture technology on the plant efficiency and energetic parameters of the system. Aspen Hysys is used to simulate Amine absorption tower and Air Separation cryogenic tower. Since the oxygen production plant, CO2 capture and transport are cost and energy intensive, the cost...
Superstructure Optimization of CO2 Capture, transport, and Utilization in Industrial Symbiosis Networks
, M.Sc. Thesis Sharif University of Technology ; Roshandel, Ramin (Supervisor)
Abstract
CO2 capture and utilization (CCU) is a promising approach to reduce and control emissions from the industry and energy sector, while also creating new jobs and value-added products. However, one of the main barriers to the widespread adoption of CCU is the high investment and operating costs, which limit its implementation to mostly government-supported research projects. To overcome this barrier, structural optimization and identification of optimal routes and formation of industrial symbiosis networks are needed. In this research, we developed a comprehensive superstructure that includes sources and sinks (in a case study), CO2 capture and separation material and technology combinations...
Solvation free energy and solubility of acetaminophen and ibuprofen in supercritical carbon dioxide: Impact of the solvent model
, Article Journal of Supercritical Fluids ; Volume 109 , 2016 , Pages 166-176 ; 08968446 (ISSN) ; Ghotbi, C ; Jahanbin Sardroodi, J ; Karimi Sabet, J ; Robert, M. A ; Sharif University of Technology
Elsevier
2016
Abstract
Classical molecular dynamics simulations are used to compute the solvation free energy of two pharmaceutical solids, namely ibuprofen and acetaminophen in carbon dioxide (CO2), over the density range of interest in supercritical processes. In order to examine the influence of the solvent model on the resulting free energies, three popular CO2 models (Zhang, EPM2, and TraPPE) are studied. Relatively large discrepancies for the solvation free energy exist between these CO2 models, suggesting that the former is sensitive to the different balances between dispersive and electrostatic forces used in these models. In particular, for the solvation of the highly polar (dipole moment of ∼5.2 Debye)...
Applicability of membrane reactor technology in industrial hydrogen producing reactions: Current effort and future directions
, Article Journal of Industrial and Engineering Chemistry ; Volume 104 , 2021 , Pages 212-230 ; 1226086X (ISSN) ; Binazadeh, M ; Sohrabi, R ; Sharif University of Technology
Korean Society of Industrial Engineering Chemistry
2021
Abstract
Potent carbon-neutral energy carriers bring a vital solution for sustained industrialization and environmental protection. Hydrogen as a novel zero-emission energy carrier offers more than twice energy per unit mass compared to other fuels. Membrane reactor technology transforms gray hydrogen to blue by selective hydrogen separation and carbon dioxide capture from the product mixture. Moreover, improved reactant conversion during reversible steam reforming of methane, methanol, and ethanol; water gas-shift; and dehydrogenation of cyclic and aliphatic hydrocarbons as well as enhanced hydrogen yield are results of selective and distributed hydrogen separation from membrane reactor. In this...
Mild steel carbon dioxide corrosion modelling in aqueous solutions
, Article Corrosion Engineering Science and Technology ; Volume 43, Issue 4 , 2008 , Pages 290-296 ; 1478422X (ISSN) ; Afshar, A ; Ghorbani, M ; Rahmaniyan, M ; Sharif University of Technology
2008
Abstract
A model for prediction of corrosion of mild steel in aqueous solutions containing carbon dioxide is proposed. In this model, formation of protective corrosion product is not yet considered, species concentration at the surface was calculated by using molecular diffusion phenomena and the diffusion equations were solved using the finite difference method. Calculated electrochemical currents at the steel surface may be used to determine the corrosion rate. The model was verified experimentally under atmospheric pressure and the effect of parameters, such as liquid velocity and pH, was investigated. The model can predict the electrochemical reaction rates when they were controlled by diffusion...
Experimental Investigation of CO2-Oil Relative Permeability
, M.Sc. Thesis Sharif University of Technology ; Vossughi, Manouchehr (Supervisor) ; Shadizadeh, Reza (Supervisor) ; Kharrat, Reyaz (Supervisor) ; Ghazanfari, Mohammad Hossain (Co-Advisor)
Abstract
Relative permeability is an important factor that controls the two phase fluid flow in porous media. The use of carbon dioxide in enhanced oil recovery methods is common. But the question is, how does the carbon dioxide affect the relative permeability curves? In this thesis, the CO2-oil relative permeability is measured in CO2 flooding process with unsteady state method. For this purpose, the core flooding apparatus is used and the results are compared with N2-oil relative permeability in N2 flooding. The results of comparison show that oil relative permeability in CO2 flooding is higher than N2 flooding. Reduction of Interfacial tension and oil viscosity, solubility of CO2 in oil and oil...
Surface Modification of Polysulfone Membrane by Plasma Treatment for CO2/CH4 Separation
, M.Sc. Thesis Sharif University of Technology ; Soltanieh, Mohammad (Supervisor)
Abstract
Low frequency (LF) O2 plasma was used to modify the surface of polysulfone (PSF) gas separation membranes. The effect of treatment time and plasma power input on the membranes was also investigated. Pure CO2 and CH4 gas permeation measurements were performed before and after plasma treatment. The results showed the increase of permeability of the treated membranes due to surface ablation and surface polarization. However, the CO2/CH4 permselectivity of the treated membranes varied from 7.7 to 45.3 depending on the treatment conditions. Attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy determined the introduction of oxygen containing polar groups on the surface...
Investigation of the Effect of Asphaltene on Interfacial Tension Behavior of CO2/Oil Systems during CO2 Injection into Asphaltenic Oil Reservoirs
, M.Sc. Thesis Sharif University of Technology ; Taghikhani, Vahid (Supervisor) ; Ayatollahi, Shahabeddin (Supervisor)
Abstract
Interfacial Tension (IFT) behavior of crude oil/CO2 system is recognized as the main factor affecting the efficiency of CO2 flooding during enhanced oil recovery (EOR) process. Adding paraffin group hydrocarbon to asphaltenic crude oils as an asphaltene precipitant component is aimed to mimic asphaltene precipitation process during crude oil production and transportation. Asphaltene precipitation would critically effects the IFT behavior of crude oil/CO2 systems. In the first part of this study, the equilibrium densities of oil samples which contain different heptane ratio were measured at different pressures and the temperature of 323 K. Then, the equilibrium IFT between CO2 and the crude...
Modeling and Analysis of Combined Heat and Power Production from Heavy Refinery Products, using Integrated Gasification and Molten Carbonate Fuel Cell Cycle
, M.Sc. Thesis Sharif University of Technology ; Roshandel, Ramin (Supervisor)
Abstract
Nowadays, the reduction of crude oil quality and the growth of environmental restrictions are the main challenges in oil refineries worldwide. The high demand of lighter refinery products and the shrinking market of the heavy products, highlighted the role of heavy residues conversion technologies.Gasification technology consumes these heavy refinery residues and produces clean syngas. By this way and the integration of gasification with power generation cycles, more value added products such as electrical energy, steam and hydrogen can be provided. For this aim to be achieved, three different scenarios are developed and investigated in this project. The first scenario includes the...
Separation of Oxygen from Gas Mixture of Carbon Dioxide and Oxygen with Cyclohexanol and Triethylene Glycol Liquid Membrane in the Presence of Metal Oxide Nanoparticles
, M.Sc. Thesis Sharif University of Technology ; Bastani, Daruoosh (Supervisor)
Abstract
In this research, the effect of feed flow concentration on the separation of gas mixture of carbon dioxide and oxygen was investigated by using supported liquid membrane in the presence of nano particles. In order to achieve this purpose, supported liquid membranes were prepared by impregnating a porous hydrophilic PVDF support with TEG, cyclohexanol, TEG/Fe3O4 nano particles and cyclohexanol/ Fe3O4 nano particles. Permeability and selectivity of mixed gases CO2 and O2 were examined at five different CO2 concentrations in feed flow, constant feed flow rate and constant total pressure difference.
In all tests, the permeance of carbon dioxide through cyclohexanol and TEG membranes was...
In all tests, the permeance of carbon dioxide through cyclohexanol and TEG membranes was...
Development of a Model for Energy, Environmental and Technical Evaluation in Iron and Steel Industry
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor)
Abstract
The iron and steel industry has faced several challenges during the recent years. There has always been an aspiration towards higher economic profitability for the system. During the mid 1970s and 1980s the energy crises caused a dramatic rise in energy costs, which led to an increased awareness in energy conservation. In recent years, climate change issues have become more important for the industry. The operating practices for an industrial system are often affected by external restrictions concerning the economical, energy and environmental efficiency of the system. There are a large number of ways to increase the system efficiency, e.g. installation of new process equipment, and practice...
Direct Synthesis of Dimethyl Ether from Carbon Dioxide
, M.Sc. Thesis Sharif University of Technology ; Kazemeini, Mohammad (Supervisor) ; Aghaziarati, Mahmoud (Co-Advisor) ; Kazemian, Masoud (Co-Advisor)
Abstract
In this research, direct synthesis of dimethyl ether (DME) from CO2 hydrogenation in three phase slurry reactor was investigated. Bifunctional catalysts composed of Cu- ZnO-Al2O3-ZrO2 as hydrogenation component and zeolite Na-Mordenite as dehydration component, with different Al2O3 and ZrO2 contents were synthesized by coprecipitating sedimentation and influences of Al2O3 and ZrO2 on CO2 conversion and DME selectivity were evaluated. Results show, both Al2O3 and ZrO2 enhanced conversion, but Al2O3 markedly increase selectivity of DME. However, when the total contents of Al2O3 and ZrO2 was increased up to 16 wt% , CO2 conversion and DME selectivity remarkably decreased. BET and XRD analyzes...
Development of an Integrated Model of Electricity & Methanol Co Production Through Solar Energy and CO2 Capture
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor)
Abstract
Emission of CO2 and its diffusion into atmosphere is associated with negative effects on the environmental such as Green House Gases effect. Various techniques of CO2 Capture in energy conversion and processing plant are investigated. A method of CO2 Capture could be based on utilization of solar energy for producing methanol. Basic design of such a system and feasibility analysis of developing that system has been considered on the subject of the present research work. Basic design and commercial feasibility of the system producing methanol through capturing CO2 from exhaust gases of a power plant and hydrogen produced by using solar energy have done such an integrated system. The main...
Investigation and Accomplishment of CO2 Capturing with Solid Sorbent
, M.Sc. Thesis Sharif University of Technology ; Safekordi, Ali Akbar (Supervisor)
Abstract
Carbon dioxide emissions account for 80% of current greenhouse gas emissions that contribute to global warming; this majority stake held by carbon dioxide indicates that reduction in its release to the atmosphere and capturing emissions accomplished is imperative in conservation of human life in earth. The aim of this project is CO2 capturing from ambient air to decrease air pollution with uses building surface that is wide available surface, as basis of adsorbent. In this research, we select CaO as absorbent that it is proven good absorbent in high temperature for CO2. We studied this absorbent in low temperature and pressure. We experimented different weight amount of sorbent 2,3,4,5,6.5...
Experimental Investigation of Enhanced Oil Recovery Using N2 Alternating CO2 Gas Injection
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Manoochehr (Supervisor) ; Shadizadeh, Reza (Supervisor) ; Kharrat, Riaz (Supervisor) ; Ghazanfari, Mohammad (Supervisor)
Abstract
Gas injection is a well-known enhanced recovery method which can improve recovery using two different displacement processes, miscible and immiscible. Typical non-hydrocarbon gases which have been utilized in these processes are carbon-dioxide and nitrogen. These gases are usually injected separately and have been rarely utilized together as a tertiary recovery process.
In this paper, we have focused on sequential carbon-dioxide and nitrogen gas injection as a novel EOR method. The periodic injections of carbon-dioxide and nitrogen have been repeated for six injection pore volumes. Sensitivity analysis of injection pressure, injection volume and injection rate have been also investigated...
In this paper, we have focused on sequential carbon-dioxide and nitrogen gas injection as a novel EOR method. The periodic injections of carbon-dioxide and nitrogen have been repeated for six injection pore volumes. Sensitivity analysis of injection pressure, injection volume and injection rate have been also investigated...
Extraction of Pigment from Walnut Husk by Supercritical CO2
, M.Sc. Thesis Sharif University of Technology ; Goodarznia, Iraj (Supervisor) ; Molaei Dehkordi, Asghar (Supervisor)
Abstract
Juglone is a naphthoquinone compound which is found in all parts of a walnut tree; including the leaf, root, walnut green husk, and bark. It is mostly used in dyeing industries. In this study, Juglone pigment is extracted from walnut husk by using the supercritical CO2 and Ethanol as a co-solvent, and the effects of parameters such as temperature, pressure, and size of husk particles on extraction efficiency are studied. The experiments have been designed based on Taguchi algorithm. Temperature and pressure range are chosen to be 35-50°C and 90-150 bar respectively. Walnut husk particles have been prepared dry from the city of Torbat Heidarieh in different average diameters; 1500, 855, 605...