Sharif Digital Repository

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... 

In this research, absorption and oxidation catalytic scenarios were examined using previous studies in the field of SO2 removal. Nanostructures zeolite 13X, 5A zeolite, gamma alumina and activated carbon were purchased, then structure, function and adsorption isotherm of each adsorbent were evaluated in 5 concentrations of 250, 500, 750, 1000 and 1250 ppm of contaminants. Final results showed that zeolite 13X compared to other Nano-adsorbents has higher ability to SO2 absorption, and thus the final tests such as temperature and pressure evaluation were performed on the selected sorbent. To further evaluation, the absorbent curves based on two models of BDST (Bed depth service time) and... 

packed columns are important in liquid-liquid extraction processes. In most studies, at first, drops are broken to small drops as much as possible and then they contact with packings. But, because of different reasons drops during their moving up coalescence together. So far, there is not serious investigation about hydrodynamics of these large drops and their breakage in packed columns. Thus, breakage of two different sizes of drops while collision to 3 different height of 4 different type of packings with two volumetric flow rates and in 2 cases of straight collision of drops to bed and collision to support plate has been investigated. Then size distribution of produced drops throughout... 

One of the main environmental problems in the world particularly in Iran is the entrance of oil pollutions from petroleum waste and its related industries into the soil. There are various methods to eliminate petroleum pollutions from the environment such as physical, chemical, thermal and biological methods. In biological remediation, the environmental pollutions are eliminated by means of plants and microorganisms. Over the last two decades, ioremediation have been studied widely by experts of various fields. One of the most advantages of bioremediation comparing with the other methods is its low cost and the ability to perform at the site (in situ).In this project, we extracted two kinds... 

In this study, a comprehensive 2D mathematical model has been developed for the simulation of physical and chemical absorption of carbon dioxide in hollow fiber membrane contactors in the presence of nanoparticles. The model were developed by considering molecular diffusion in radial and axial directions as well as non-wetting conditions. Carbon dioxide absorption was simulated from a gas mixture containing carbon dioxide and air, that flows in the shell. Also, absorbent containing nanoparticles flows in tube side and counter currently. Effects of presence of nanoparticles were modeled by taking into account two prominent mechanisms proposed in the literature for mass transfer enhancement in... 

In this study, experimental results of Ahvaz produced water treatment obtained in ultrafiltration process using a polymeric membrane formed from Polyacrylonitrile (PAN) with 0.2 µm poreshave been reported. In this process the effects of different factors including transmembrane pressure (TMP), cross flow velocity (CFV) and feed temperature on permeate flux, membrane fouling resistance and TOC rejection was investigated. The results show that optimum conditionswere found in the range of TMP: 1.5-3 bar, CFV: 1-1.5 m/s and operating temperature 40°C.Results show that under optimum conditions the final permeate flux for produced water of Asmari outlet of Skimmer unit was 30 L/m2.h, and the... 

Surface phenomena and dynamic Interfacial properties play an important roles in gas- liquid and liquid-liquid multiphase process from various industrial applications to understand fundamental phenomena. However, there is no experimental equipment and efficient methods for quantitative and detail investigation of interfacial properties under fast and non-equilibrium dynamic condition due to mobility and refreshing of interface (such as rising bubble). Also existing models accompanied with a lot of simplifications which is not yet validated with a proper experimental data. development of laboratory equipment base on measuring momentary capillary pressure and presenting a new experimental... 

Nowadays, different processes are designed in order to convert raw materials to value added products. One of these is the Bentonite sulfur production process. The most important equipment in this process are stirred tanks where mixing operation of molten sulfur with some additives such as functionalized Bentonite and oxides of iron, zinc and manganese are performed.
In this thesis, following the design and making of a laboratory scale glass baffled stirred tank, the viscosity of molten sulfur and additive suspension has been measured at different temperature (125, 130 and 135oC) and several formulations. Concentration profile of Bentonite has also been obtained by means of local sampling...