Sharif Digital Repository

Dehydrogenation of C10-C14 normal paraffins on Pt/alumina catalyst is a reaction of prime importance particularly to the detergent industry for the manufacture of the active ingredients. In this thesis, the modifying effect of Zn, Li, K, and Mg on the activity and selectivity of the Pt-Sn/γ-Al2O3 dehydrogenation catalysts were investigated. The catalysts were prepared by co-impregnation, characterized by TPR, BET, SEM, EDAX and XRD techniques and tested in a tubular reactor. Zinc reduced the activity of Pt-Sn alloy and hence reduced the catalyst activity in the dehydrogenation reaction and enhanced its selectivity to normal mono olefins. The addition of Li, K, and Mg to Pt-Sn/γ-Al2O3... 

Nano and microsize H-ZSM-5 were synthesized by hydrothermal crystallization method with same batch composition to investigate the effect of crystallite size of H-ZSM-5 in the methanol conversion to propylene (MTP) process. The average particle size of nano and microsize H-ZSM-5 were obtained in the range of 0.15- 0.2 and 1- 2 µm, respectively. Also, optimized catalyst of Petrochemical Research and Technology Company was synthesized using terapropylammonium bromide as template. Nowadays, terapropylammonium bromide (TPABr) is cheeper than terapropylammonium hydroxide (TPAOH); therefore we used it as tamplate. Activity tests were conducted at operating conditions of T= 460˚C, P=1 atm and WHSV... 

Long-term deactivation of a commercial K-promoted Fe2O3 catalyst used in the dehydrogenation of ethylbenzene to styrene monomer was studied using thirty months of operating data of three industrial SM radial fixed bed adiabatic reactors. The Langmuir-Hinshelwood, Hougen-Watson model (LHHW) was used for reaction kinetics modeling. The kinetics of coking from ethylbenzene and styrene and the short-term deactivation function due to the quick coke formation were also considered in the model. The kinetics of long-term deactivation of the catalyst for ethylbenzene dehydrogenation to styrene between 550 and 630 °C were determined by allowing the effects of temperature and time on the catalyst... 

In this research, a mathematical model was developed to simulate a two-phase fluidized bed reactor for oxidative dehydrogenation of propane to propylene. Since the assumption of minimum fluidization condition for the emulsion phase is not realistic , the hydrodynamic structure proposed by Cui et al. was used in this study. The mass balances in unsteady state was obtained in a control volume. The differential equations contain three terms, corresponding to the mass transfer by convection, the exchange between phases and the reaction. All differential equations based upon material balances, hydrodynamics and kinetics for all components were solved numerically using MATLAB software 2010a.... 

Catalytic cracking is one of the most important unit and process of catalytic processes in the world that transforms heavy and cheap oil materials to lighter and valuable materials. Nowadays due to global increase in fuel consumption and the need to transform heavy materials to lighter ones there is an increasing attention and need to this process.
This system consists of two main sections. Riser reactor and regenerator to burn the Coke that is accumulated on the catalyst which in this project we tend to simulate the riser reactor of FCC unit of Abadan refinery in which the cracking is done. The considered kinetic model, is a three-lump model that is able to predict the conversion... 

The water-gas shift reaction, as a vital reaction in industry especially as a source of hydrogen for the manufacture of ammonia, is influential for all of the scientists and researchers in chemical engineering all around the world. In this research, high temperature water-gas shift (HTS) catalysts were investigated in order to study synthesis parameters and improvement of their performance and catalytic activity. The two catalyst categories; non pre-active and pre-active (magnetite-based samples, not requiring a reduction step prior to use) were prepared by co-precipitation method, using chloride, sulfate and nitrate metal (Fe, Cr, Cu) precursors and NaOH as precipitating agent (the aging... 

Upscaling is an important step in hydrocarbon reservoir modeling which reduces the number of grid blocks of high detailed geological models to prepare them for flow simulation. This helps to speed up computational process, to keep the simulation (CPU) time within a reasonable range and to make future engineering analysis (history matching, comparison of production scenarios, Monte Carlo simulation and etc.) possible. The accuracy of post processing analysis heavily depends on the robustness and validation of the applied upscaling method. Although numerous methods have been proposed in the literature, overemphasizing the effect of scale on the behavior of complex governing equations has...