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Pore Network Modeling of Membrane Mass Transport for Gas Separation
, M.Sc. Thesis Sharif University of Technology ; Soltanieh, Mohammad (Supervisor) ; Bastani, Daryush (Supervisor) ; Jamshidi, Saeed (Co-Supervisor)
Abstract
The purpose of this research is to model transport and separation of single and gas mixtures through pore network modeling in dense membranes. In the first part of the project, the mass transfer and governing mechanisms of transport are investigated. In the second part of the project, simulation of membrane pore network in 3D of Cartesian coordinate is done. In the third part of the project permeability of single gas and ideal selectivity of binary gases for an actual membrane by desired mechanism are calculated. Then the results of pore network modeling were compare with the results from molecular dynamic simulation for single gas in polyurethane membrane with reasonable agreement. In this...
Green Supply Chain Management by Minimizing Carbon Footprint, Case Study KALLEH Meat Products Company
, M.Sc. Thesis Sharif University of Technology ; Abrishamchi, Ahmad (Supervisor)
Abstract
When increased emissions are combined with a carbon tax or emissions trading system, the result is a supply chain with increased costs attributable to the emission generated on the different parts of supply chain. Most traditional supply chain design models do not take emissions and carbon costs into account. Hence, there is a need to incorporate emission costs into a supply chain optimization model to see how the optimal supply chain configuration may be affected by the additional expenses. This thesis presents a mathematical programming model for the design of green supply chains. The costs of carbon dioxide equivalent emissions were incorporated in the objective function, along with the...
Smulation of Hydrogen Production by the Process of Thermal Decomposition of Methane
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor)
Abstract
Different disadvantages associated with using fossil fuels as the main energy source including crisis of wells’ depletion and serious environmental problems, causing by the emission of large quantities of greenhouse gases (GHG), especially carbon dioxide (CO2), has increased attention to replacing them with renewable and clean fuels such as wind, solar, and geothermal energy sources. Hydrogen, as a clean energy carrier, is one of the best fuels in terms of the environment and cost. So, it is recently receiving increasing attention and it may one day replace fossil fuels for various applications such as in automobiles and power stations. The main subject of this thesis was surveying the...
Numerical Study of Various Parameters on Blasting Gases and Dust Ventilation in Mines
, M.Sc. Thesis Sharif University of Technology ; Farhanieh, Bijan (Supervisor)
Abstract
One of the methods of drilling coal mines is mine blasting (drilling with explosives). In this method, explosives such as dynamite are used to excavate the mine and destroy the coal seams. During this type of drilling, in addition to dust, dangerous toxic gases are also produced, so quick and proper ventilation of mine tunnels is necessary in this type of drilling.Depending on the type of mining, the required ventilation system may be different. For example, if the drilling method is long-term method, the mine ventilation is of the U type, but if the mine drilling is the sub-level caving type, auxiliary ventilation is used.In this study, the method of mining is sub-level caving, so that one...
Developing A Model for Evaluation of Energy Recovery From Flared Gas
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor) ; Sattari, Sourena (Co-Advisor)
Abstract
According to the World Bank, nearly 154 billion cubic meters of gas is flared in the world every year. Iran is known as the third gas flaring country by burning about 11.4 bcm (approximately 8% of the total amount). Flared gas is a rich gas and has a high heating value. Therefore flaring it equals to waste of a valuable source of energy. In addition, serious concerns about its environmental effects due to emission of considerable amounts of CO2, SOx, NOx and other pollutants, makes it necessary to find a solution to reduce gas flaring. There are several ways for flared gas utilization including electricity generation, injecting into oil wells for enhanced oil recovery, gas processing and...
, M.Sc. Thesis Sharif University of Technology ; Soltanieh, Mohammad (Supervisor) ; Seifkordi, Ali Akbar (Supervisor)
Abstract
Using membrane contactors for acid gas removal, combines the advantages of membrane based separation processes and traditional ones. In this project we aim to study the use of a membrane absorption system for sweetening gas streams containing mixed acid gases with composition similar to raw natural gas. H2S and CO2 exist in the gas stream simultaneously which can be removed by mixture of alkanolamine solvents, including MDEA, DEA and MEA, are used for treating. A lab-scale membrane absorption setup with feed capacity of 2 lit/min, was designed, constructed and commissioned. Several hollow fiber modules equipped with PSf and PVDF membranes were fabricated. Our results revealed that reaching...
Investigation of EDC Turbulent Combustion Model for Flameless Combustion Regime in a Certain Combustion Chamber
, M.Sc. Thesis Sharif University of Technology ; Farshchi, Mohammad (Supervisor)
Abstract
Reducing carbon emissions emanated from combustion of fossil fuels is a challenging problem and consumes huge amount of money that is put into research every year. Nitrogen oxides are among the most important pollutants which have been at the center of attention of industries and international environment protection organizations, especially due to their increased production by commercial aircrafts at higher altitudes of the atmosphere. Flameless is a combustion regime that has been independently discovered by different research teams while working on reducing nitrogen oxides from burning fossil fuels in the early 1990s, and afterwards has been studied for its exclusive characteristics in...
An Investigation Into Improving Double And Triple Glazed Windows
, M.Sc. Thesis Sharif University of Technology ; Arhami, Mohammad (Supervisor)
Abstract
Windows are the main source of energy loss in buildings. One way to improve thermal performance of insulation windows is to use inert gases in them. Some of these gases are expensive and there is a need to find the optimum mixture of theses gases with cheaper ones in order to reduce the initial price of these windows. In the first section of this research through calculating the U-Value, thermal performance of sample windows which are filled with different mixtures of Argon, Carbon dioxide and Air is investigated in order to determine the optimum mixture of them. For this purpose a two and a three glazed sample window was prepared and each one was filled with different ratios of the...
Design of a Dynamic Route Optimisation Algorithm for Ships
, M.Sc. Thesis Sharif University of Technology ;
Abstract
Marine transportation is an essential aspect of global trade, as it is responsible for transporting large quantities of goods and commodities between different countries and continents. The efficient optimization of shipping routes can greatly reduce operational costs, save time, and increase the overall competitiveness of the maritime industry. One of the most critical aspects of route optimization is the selection of the most efficient path, taking into account various constraints such as fuel consumption, voyage duration, vessel speed, and port constraints. The PSO algorithm has been successfully applied to a variety of optimization problems, including the optimization of marine routes....
Examination of Activity of Three-Way Catalysts Toward CO and Hydrocarbon Emission Reduction from Tehran Gasoline Taxis
, M.Sc. Thesis Sharif University of Technology ; Hamzehlouyan, Tayebeh (Supervisor) ; Hosseini, Vahid (Co-Supervisor)
Abstract
Air pollution is one of the main environmental problems in Iran's metropolises, especially in the city of Tehran. Taxis have a significant contribution to pollution due to the long distances they travel during the day. Due to the fact that the operation of automotive three-way catalysts is a function of their operating conditions, and considering the different fuel composition in Iran and the specific conditions of engine performance, exhaust gas composition can be different from similar cases abroad. A commercial three-way catalyst was tested to evaluate its performance under conditions relevant to the exhaust gas of Tehran's taxis fleet. In this study, CO and C3H6 were considered as the...
Synthesis and Evaluation of Modified Zeolites for Separation of Acidic Gases
, M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad (Supervisor) ; Soltanali, Saeed (Supervisor) ; Ghasabzadeh, Hamid (Co-Supervisor)
Abstract
The adsorption equilibria of carbon dioxide, methane, and nitrogen on pelletized cation-exchanged faujasite zeolite (with alkali, alkaline earth, and transition metal ions) have been investigated by a volumetric apparatus. The standard instrumental analytical techniques, including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) coupled with energy dispersive X-ray spectroscopy (EDX), and atomic absorption spectroscopy (AAS) were utilized to characterize binder-free modified zeolites. The EDX spectra and AAS results revealed that the ion-exchange was successfully achieved with expected tendencies. The results indicate that the type of cation present in the zeolite...
Emission Mitigation Strategies for Combustion Sources
, M.Sc. Thesis Sharif University of Technology ; Arhami, Mohammad (Supervisor) ; Abrishamchi, Ahmad (Co-Supervisor) ; Azarmi, Farhad (Co-Supervisor)
Abstract
Scientific studies, conducted over the world, show that an immense portion of pollutants and greenhouse gases emission to the atmosphere are the direct result of the incineration of fossil fuels in industrial units. These industrial units include chemical industries, power plants, metal industry, etc. Therefore, there is a tremendous necessity to reduce the pollutants emission from these industries immediately and effectively. Meanwhile, in order to mitigate the emission to the atmosphere, there should be a meticulous estimation of pollutants emission from various sources. Hence, in a project called "standardization of emission of pollutants from diverse industrial units in Iran", the...
Dispersion Modeling of Air Pollutants from Gas Flares
, M.Sc. Thesis Sharif University of Technology ; Arhami, Mohammad (Supervisor)
Abstract
In the current study, the dispersion of four major air pollutants, sulphur dioxide, nitrogen oxide, carbon monoxide, and particulate matter from gas flares of an oil field, in Iran, was investigated for year 2011 by application of a conventional steady state Gaussian dispersion model, AERMOD. Two scenarios were applied in modeling, first application of flare parameters based on technologies that exist and the other one using new technologies in flares such as steam assisted with better combustion efficiency. Due to the complexity of meteorological parameters in modeling area, CALPUFF model was used in this study. CALPUFF which is a more advanced model that considers the effect of...
Preparation and Characterization of Mixed-Matrix Composite Membranes Based On Metal-organic Frameworks/Acrylate Polyurethane to Separate Carbon Dioxide from Nitrogen
, Ph.D. Dissertation Sharif University of Technology ; Shojaei, Akbar (Supervisor) ; Mousavi, Abbas (Supervisor)
Abstract
Composite membranes are one of the promising membranes for overcoming the limitations of conventional membranes in gas separation application by improving the permeability and selectivity. However, it is still very challenging to achieve adhesion interface between the top selective layer and the bottom support layer. The present study demonstrates that this challenge can be overcome appropriately by utilizing a series of adhesive polymer as selective layer to prepare composite membrane. To this end, in the first section a series of acrylate-terminated polyurethanes (APUs) based on poly(ethylene glycol) (PEG) with different molecular weights (Mn) of 600, 1000, 1500, 2000 and 4000 g/mol,...
Modifications in Commercial Diesel Engines to Perform Under Difficult Respiration Conditions
, M.Sc. Thesis Sharif University of Technology ; Durali, Mohammad (Supervisor)
Abstract
In this project we are about to adopt a method for implementing commercial diesel engines (truck and bus engines) in applications with difficult respiration condition like what happens in a submarine. To this end, working conditions of such engines are introduced and standard constraints are explained. Then the structure of already manufactured submarine engines is presented. At this point an engine from known manufacturers was selected for calculations to be performed on it. Since test and measurement equipments were not yet ready, simulation using computer software (GT-POWER v6.1) was selected as the solving method. First, the engine was modeled in its nominal working conditions. After...
Synthesis and Characterization of Nano-zeolite Membranes for Natural Gas Sweetening
, Ph.D. Dissertation Sharif University of Technology ; Soltanieh, Mohammad (Supervisor)
Abstract
Zeolite membranes are of interest due to their special properties; thermal and mechanical resistances and non-plasticization property in gas separations. Therefore, separation of H2S from natural gas by these membranes is the main goal of this thesis which is not investigated in the world. After some theoretical investigations including diffusion mechanisms of gases in the zeolites and adsorption mechanism of H2S on the zeolites, pure silica CHA-type (Si-CHA) zeolite was selected. After successful synthesis of Si-CHA zeolite, adsorption isotherms of H2S, CO2, and CH4 on the Si-CHA zeolite were measured over pressure range of 0-190 kPa and temperatures of 25 °C, 50 °C, and 75 °C. Acid gases...
The Effect of the Number of Electric Vehicles on the Level of Environmental Pollution
, M.Sc. Thesis Sharif University of Technology ; Hosseini, Hamid (Supervisor)
Abstract
The transportation and electricity industries are major emitters of greenhouse gases (GHGs). In order to reduce emissions, several strategies have been proposed, including plug-in electric vehicle (PEV) use and integration of renewable energy sources (RESs). To reduce the concern emission rate while considering economic constraints, it is important to examine different scenarios of incorporating these elements. To investigate the effectiveness of using PEVs and RES from various perspectives, this study utilizes a combined economic emission dispatch (CEED). The influence of emission and cost coefficients is examined in a sensitivity analysis. In the proposed model, two test cases containing...
Models for Technology Assessment and Management of Gas Flare and Developing Strategies for Reducing Flared Gas
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor)
Abstract
The need for planning for the management and recovery of flare gases is an important issue in the energy sector of the country. On a day, about 46 million cubic meters of gas in Iran is burning in the torch, which in addition to the destruction of non-renewable energies, contributes to environmental pollution and emissions of greenhouse gases. Gas burning is one of the few pollutant activities that is due to short-term economic revenues, system design weaknesses, and lack of management in the operation process, with no service provided or value added. Iran is ranked third in the world according to satellite data among the countries that are burning flares. Accordingly, by burning 17/7...
Modeling of Membrane Contactors For Separation of Multi-Component Gases by Mixtures of Solvents
, M.Sc. Thesis Sharif University of Technology ; Soltanieh, Mohammad (Supervisor)
Abstract
In the present work a comprehensive mathematical model has been developed for CFD simulation of transport phenomena in the hollow fiber membrane contactors. The system which has been studied was a gas sweetening including methane, carbon dioxide, and hydrogen sulfide in the gas phase and MEA aqueous solution as the solvent. Effects of temperature distribution on the contactor efficiency predicted taking into account the heat of solution, the heat of reaction, and the viscous dissipation. Major focus of the present study was on dynamic behavior of the contactor considering the entrance regions of momentum, energy, and mass transfers. CFD methods have been developed to solve the nonlinear...
Technical and Economical Feasibility Study of Using Flare Gas for Converting to Other Products in Iran
, M.Sc. Thesis Sharif University of Technology ; Sattari, Sourena (Supervisor)
Abstract
The Increasing trend of gas flaring over oil fields and gas process systems in Iran not only causes several environmental problems, but makes the economical resources useless as well. Considering the high amount of flaring and old facilities, one of the best solutions is the recovery of the flare gas in Iran. It seems that collecting the flare gas is not possible in different sectors. Therefore, using a plant for converting flare gas to other products must be logical. In this project, the feasibility study of converting flare gas to other products is studied. For this reason, a methanol plant is simulated; whose input feed is the content of flare gas of the South of Iran (Marun and Siri)....