Sharif Digital Repository

In a polyvinyl alcohol (PVA) plant, equal moles of methyl acetate are produced as byproduct for every mole of PVA. Since there is a little demand for impure methyl acetate, it is converted to methanol and acetic acid as raw materials of PVA plant via hydrolysis reaction. Duo to the small equilibrium constant of hydrolysis reaction of methyl acetate, the conventional process (including reaction and separation sections) suffers some problems such as large recycle flow and high energy consumption. Therefore, reactive distillation is introduced as an alternative for these processes. Since the reactive distillation integrates both reaction and separation in a single vessel, it has more complex... 

The usages of Autonomous Underwater Vehicles (AUV) are limited due to the lack of suitable portable energy sources. Researches show that chargeable batteries and fuel cells are the most appropriate energy source for AUVs in near future. The main purpose of thesis is the modeling and obtaining the governing equations for Aluminum/Air batteries containing seawater, the so-called semi fuel cell. The steady state governing equations include Navier-Stocks equations (Hydraulic-Boundary layer), chemical ionic species mass balance at boundary layer velocity field, electrochemical equations in the electrolyte and the electrode surface, equations of motion of the hydrogen bubbles and equations for the... 

There are many limitations to determine relationships within biological systems. Among the limitations of these systems, one can consider the lack of sufficient information about them, such as the complete knowledge of many networks, the lack of reaction information, the complexity of the analysis of these reactions, etc. One of the methods to analyze these systems is called flux balance analysis. This method consists of three parts: objective function, equal constraints and unequal constraints. Among the features available in this method, we can mention less need for experimental information and no need for high processing systems. In order to determine the objective functions in this... 

Oxidative coupling of methane (OCM) in a fixed bed tubular reactor over Mn-Na2WO4/SiO2 catalyst has been studied. Four kinetic models have been considered for OCM reactions. Based on an objective function and using genetic algorithm, kinetic parameters have been estimated. A reactor tube with 20 mm diameter and 400 mm length surrounded by molten salt for removing heat of reaction has been used for experimental study. Effects of different factors such as CH4/O2 ratio, nitrogen content in feed and contact time are investigated experimentally and by simulation. A good agreement has been observed between simulation and experimental data. Oxidative coupling of methane (OCM) in an industrial fixed...