Sharif Digital Repository

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).... 

This thesis encompasses two parallel, but independent subjects as follow: The first part of the thesis deals with synthesis of bimetallic Ni-Au nanoparticles (Bi Ni-Au), and application of them as electrodes in the methanol fuel cells. The Bi Ni-Au nanoparticles for this purpose were synthesized by controlled reduction of HAuCl3 and NiCl3 in the aqueous medium using NaBH4 as reductant and PVP as stabilizer, and immobilized on the surface of a glassy carbon (GC) electrode by means of Nafion polymer. The obtained electrode then was conditioned in an alkaline solution by cyclic voltammetric method in potential range 100 -700 mV (vs. Ag/AgCl). Physicochemical characterizations of the... 

Propylene is one of the key material in petrochemical industries. In recent years, as propylene demand increases, development of new methods alongside traditional ways in production of propylene seems essential. The production of propylene from methanol using zeolitic catalysts is as one of this new methods. This method in recent years has got attention. H-ZSM-5 zeolite is one of the best catalysts appropriate for this process. However, rapid deactivation is the main problem this catalyst at the present time. Therefore, more research in order to increase stability and lifetime has been performed. The uses of promoters are as one of the simplest improvement methods of H-ZSM-5 zeolite.... 

Cell of fuel methanol can store fuel easily, because they can suitable for resources of energy with ambulant applications. As for with the extensive of electrical haul instruments, they attention to the use of fuel cell methanol. In this project a fuel cell methanol consist of different branches such as cathode, Anode, substrates of membrane and influx, has modeled with the form of flat three dimensional. This model consist of ambulant theorems, transfer of mass, chemistry theorems and reflexes of electro chemistry in spongy environment. As for with a little knowledge that is related to the oxidation of methanol, the first research is related to this reflex and the knowledge of mathematic... 

In this study a systematic effort was made to investigate the poisoning effect of sulfur-containing materials on the electro- oxidation of methanol and ethanol on Ni and Cu electrodes in alkaline solutions by the methods of cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. Activation energy of methanol electro-oxidation in the absence of Na2S was obtained 30.7 kJ/mol by cyclic voltammetric at different temperatures, and its values increased by increase in Na2S concentrations to 97kJ/mol. Na2S adsorption isotherms corresponded with Langmuire isotherm, equilibrium constants of adsorption – desorption and adsorption enthalpy (ΔHads= -62kJ/mol) were calculated for... 

Methanol to Olefin (MTO) process is a part of the Methanol to Gasoline (MTG) production in a catalytic bed. Usually for this process, HZSM-5 or SAPO-n catalyst is used. In this research, dynamic modeling and simulation of the methanol to olefin catalytic reactor using HZSM-5 as the catalyst is done. The system is modeled based on the kinetic model for HZSM-5 presented by Castilla in 1999 [22]. Since the reaction is exothermic, taking use of a cooling system is essential. According to the high reactor temperature, a molten salt environment is used as the cooling media. In this cooling system, the molten salt absorbs heat of reaction from the reactor tubes and transfers it to a coil connected... 

Nowadays, with respect to environmental pollution and energy supply, producing gasoline from methanol or syngas is one of the most interesting research subjects. Gasoline production from methanol is a catalytic process that produces high-quality gasoline with minimum unwanted compounds. So this gasoline is a clean fuel and it can be replaced to petroleum gasoline. Because of that, it can be a valuable process in the petrochemical industry. One of the most important aspects of this process is catalyst deactivation with respect to time on stream. Catalyst deactivation is usually caused by poisoning, sintering, blocking pores, and coking. In this research, material and energy balance equations... 

Titanium nitride-carbon nanocomposites are synthesized by the reaction of TiCl4 and NaN3 in supercritical benzene medium that also serves as a carbon source. In order to improve the crystallinity of the as-prepared precursor (SI), it is further heat-treated at 1000 ˚C for 3-10 h using anhydrous ammonia and UHP nitrogen atmospheres at 1000 ˚C (SIII-SV). Moreover, to improve electrochemical behavior, the synthesized nanocomposite (SIV) is modified with Pt nanoparticles using a polyol process. For better understanding of synthesized catalyst nature and justifying their variant ORR activity several analyses are done. X-ray diffraction (XRD), Raman spectrum, field emission scanning electron... 

Homogenous carbonylation of methanol is a major way to acetic acid. In this study central composite design (CCD) at five level (-1.63, -1, 0, +1, +1.63) combined with response surface methodology (RSM) have been applied to optimize carbonylation of methanol using ruthenium promoted iridium catalyst in homogenous phase. The effect of seven process variables including; temperature, pressure, iridium, ruthenium, methyl iodide, methyl acetate and water concentrations as well as, their interactions were modeled. The determined R2 values greater than 0.9 for the rate, methane, carbon dioxide and hydrogen formation data, confirmed quadratic equation properly fitted obtained experimental data. The... 

In this research, nanocomposite containing reduced graphene oxide nanosheets (RGO) and trimetallic three-dimensional (3D) Pt-Pd-Co porous nanostructures was fabricated by galvanic replacement technique. First, GO suspension was drop-casted on the electrode surface, then GO film reduction was carried out by cycling the potential in negative direction to form the RGO on GCE (RGO/GCE). Then, electrodeposition of the cobalt nanoparticles (CoNPs) as sacrificial seeds was performed onto the RGO/GCE by using cyclic voltammetry. Afterward, Pt-Pd-Co 3D porous nanostructures fabrication occurs through galvanic replacement method based on a spontaneous redox process between CoNPs and solution...