Iran National Petrochemical Company

Tehran, Iran

Iran National Petrochemical Company

Tehran, Iran
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Sahebdelfar S.,Iran National Petrochemical Company
International Journal of Hydrogen Energy | Year: 2017

The thermodynamic equilibrium of steam reforming of propionic acid (HPAc) as a bio-oil model compound was studied over a wide range of reaction conditions (T = 500-900 °C, P = 1-10 bar and H2O/HPAc = 0-4 mol/mol) using non-stoichiometric equilibrium models. The effect of operating conditions on equilibrium conversion, product composition and coke formation was studied. The equilibrium calculations indicate nearly complete conversion of propionic acid under these conditions. Additionally, carbon and methane formation are unfavorable at high temperatures and high steam to carbon (S/C) ratios. The hydrogen yield versus S/C ratio passes a maximum, the value and position of which depends on temperature. The thermodynamic equilibrium results for HPAc fit favorably with experimental data for real bio-oil steam reforming under same reaction conditions. © 2017 Hydrogen Energy Publications LLC.


Yaripour F.,Amirkabir University of Technology | Shariatinia Z.,Amirkabir University of Technology | Sahebdelfar S.,Iran National Petrochemical Company | Irandoukht A.,Research Institute of Petroleum Industry RIPI
Microporous and Mesoporous Materials | Year: 2015

The effect of boron incorporation into H-ZSM-5 nanocatalyst on the stability, product distribution and hydrocarbons selectivity in methanol to olefins (MTO) reaction was investigated. The reference and boron-modified ZSM-5 nanocatalysts were prepared by hydrothermal method. The fresh and used nanocatalysts were characterized using TG-DTA, XRD, FE-SEM, BET, FT-IR, TPH, TPO and NH3-TPD techniques. The performance test runs of the two H-ZSM-5 and [B]-H-ZSM-5 samples were conducted in a fixed-bed reactor at T = 480 °C, P = 1 atm, methanol WHSV = 0.9 h-1 with methanol to water weight ratio of unity in the feed. The results revealed that propylene selectivity does not change significantly with the isomorphous substitution of B in H-ZSM-5 zeolite. However, the lifetime of the modified zeolite (1300 h) showed a significant increase compared to that of the reference sample (340 h). The considerable enhancement of the lifetime and catalytic stability could be attributed to reduction of strong/mild acid sites ratio as well as small crystal size of the [B]-H-ZSM-5 nanocatalyst. The characterization of the deactivated nanocatalysts showed that incorporation of boron decreased both rates of coke formation and coke-susceptibility of the ZSM-5 nanocatalyst. © 2014 Elsevier Inc. All rights reserved.


Moradi G.R.,Catalyst Research Center | Yaripour F.,Iran National Petrochemical Company | Vale-Sheyda P.,Catalyst Research Center
Fuel Processing Technology | Year: 2010

The conversion of methanol to dimethyl ether was carried out over various commercial mordenite and ion-exchanged catalysts to evaluate the catalytic performance of mordenite catalysts with different pore structures and acidities. These catalysts were compared for their catalytic properties in a fixed-bed reactor at 1 atm, 573 K and LHSV of 2.84 h- 1. The catalysts were characterized by BET, ICP, NH3-TPD, XRD, TGA and FT-IR techniques. The ion-exchanged mordenite showed higher activity, selectivity and good stability in dehydration of methanol due to the addition of medium acid sites. Also, the effect of water on catalyst deactivation was investigated over two selected catalysts in order to develop a suitable catalyst for synthesis of dimethyl ether. It was found that the H-mordenite catalyst supplied by Süd-chemie Co., (MCDH-1) was more active and less deactivated than another one in a feed containing 20 wt.% water. © 2009 Elsevier B.V. All rights reserved.


Asadieraghi M.,University of Malaya | Asadieraghi M.,Iran National Petrochemical Company | Wan Daud W.M.A.,University of Malaya
Energy Conversion and Management | Year: 2014

To eliminate the negative impacts of inorganic constituents during biomass thermochemical processes, leaching method by different diluted acid solutions was chosen. The different palm oil biomass samples (palm kernel shell (PKS), empty fruit bunches (EFB) and palm mesocarp fiber (PMF)) were pretreated by various diluted acid solutions (H2SO4, HClO4, HF, HNO3, HCl). Acids with the highest degrees of demineralization were selected to investigate the dematerialization impacts on the biomass thermal characteristics and physiochemical structure. Thermogravimetric analysis coupled with mass spectroscopy (TGA-MS) and Fourier transform infrared spectroscopy (TGA-FTIR) were employed to examine the biomass thermal degradation. TGA and DTG (Derivative thermogravimetry) indicated that the maximum degradation temperatures increased after acid pretreatment due to the minerals catalytic effects. The main permanent evolved gases comprising H 2, CO2, CO were detected online during analysis. The major permanent gases produced at the temperature range of 250-750 °C were attributed to the condensable vapors cracking and probably some secondary reactions. The physiochemical structure change of the acid-treated biomass samples was examined by using Brunauer Emmett Teller (BET) method, Scanning Electron Microscope (SEM) and FTIR. The pyrolysis kinetics of the different palm oil biomasses were investigated using first order reaction model. © 2014 Elsevier Ltd. All rights reserved.


Zangeneh F.T.,Iran National Petrochemical Company | Sahebdelfar S.,Iran National Petrochemical Company | Ravanchi M.T.,Iran National Petrochemical Company
Journal of Natural Gas Chemistry | Year: 2011

The increase of atmospheric carbon dioxide and the global warming due to its greenhouse effect resulted in worldwide concerns. On the other hand, carbon dioxide might be considered as a valuable and renewable carbon source. One approach to reduce carbon dioxide emissions could be its capture and recycle via transformation into chemicals using the technologies in C1 chemistry. Despite its great interest, there are difficulties in CO2 separation on the one hand, and thermodynamic stability of carbon dioxide molecule rendering its chemical activity low on the other hand. Carbon dioxide has been already used in petrochemical industries for production of limited chemicals such as urea. The utilization of carbon dioxide does not necessarily involve development of new processes, and in certain processes such as methanol synthesis and methane steam reforming, addition of CO2 into the feed results in its utilization and increases carbon efficiency. In other cases, modifications in catalyst and/or processes, or even new catalysts and processes, are necessary. In either case, catalysis plays a crucial role in carbon dioxide conversion and effective catalysts are required for commercial realization of the related processes. Technologies for CO2 utilization are emerging after many years of research and development efforts. © 2011 CAS/DICP.


Gharibi M.,Iran National Petrochemical Company | Zangeneh F.T.,Iran National Petrochemical Company | Yaripour F.,Iran National Petrochemical Company | Sahebdelfar S.,Iran National Petrochemical Company
Applied Catalysis A: General | Year: 2012

The conversion of natural gas (methane) as an alternative to petroleum into valuable chemicals and clean fuels has received much attention. However, because of high stability and symmetry of methane molecule, relatively few number of natural gas conversions, mostly indirect routes, have been commercialized and the remainders are still not competitive to petroleum-based processes and are in research and development stage. With the advent of nanocatalysts in chemical processes and energy sector, the potentials of these catalysts in natural gas conversions have been studied extensively all around the world. In indirect conversions, especially gas-to-liquid (GTL) technologies, effective nanocatalysts have been developed. However, in direct conversions, further research and development works are necessary. In this work, the advances in application of nanocatalysts in natural gas conversions are reviewed and areas for further research are addressed. Both theoretical aspects such as density functional theory (DFT) and characterizations and practical achievements in scientific and patent literature will be considered. © 2012 Elsevier B.V. All rights reserved.


Nasr M.R.J.,Iran National Petrochemical Company | Khalaj A.H.,Iran National Petrochemical Company
Heat Transfer Engineering | Year: 2010

In the research described here, artificial neural network (ANN) approach has been utilized to characterize the thermohydraulic behavior of corrugated tubes combined with twisted tape inserts in a turbulent flow regime. The experimental data sets were extracted from 57 tubes, 9 and 3 spirally corrugated tubes with varying geometries combined with 5 and 4 twisted tapes with different pitches. The tests were carried out with Reynolds numbers ranging from 3000 to 60,000. The experimental data sets have been utilized in training and validation of the ANN in order to predict the heat transfer coefficients and friction factors inside the corrugated tubes combined with twisted tape inserts, and the results were compared to the experimental data. The mean relative errors between the predicted results and experimental data were less than 2.9% for the heat transfer coefficients and less than 0.36% for the friction factor. The performance of the neural networks was found to be superior in comparison with the models correlated in the form of mathematical functions with their own assumptions. The results of this study suggested that ANN can be considered as a powerful tool and can be easily utilized to predict the performance of thermal systems in engineering applications.


Ghasemi H.,Iran National Petrochemical Company
Engineering Failure Analysis | Year: 2011

Being inexpensive and readily available, carbon steel is considered as the material of choice for majority of applications in the petroleum refining industry. However, carbon steel is unsuitable for applications involving certain corrosive species such as sulfur compounds. In this work the causes of heater tubes rupture in BPC have been investigated. Our results indicate that the major cause for premature failure is high temperature sulfidation along with erosion due to turbulence. This study shows that the corrosion rate of the tubes does not follow McConomy law and it is much higher than the one predicted by McConomy curves. As a result, carbon steel is not a suitable material for such heater tubes, where the gas condensate contains high amount of sulfur compounds especially mercaptans. © 2010 Elsevier Ltd.


Hassanpour S.,Babol Noshirvani University of Technology | Yaripour F.,Iran National Petrochemical Company | Taghizadeh M.,Babol Noshirvani University of Technology
Fuel Processing Technology | Year: 2010

The conversion of methanol to dimethyl ether was carried out over various commercial zeolites and modified H-ZSM-5 catalysts to evaluate their catalytic performance. A series of commercially available zeolite samples were used for vapor-phase dehydration of methanol to DME. Catalyst screening tests were performed in a fixed-bed reactor under the same operating conditions (T = 300 °C, P = 16 barg, WHSV = 3.8 h-1). It was found that all the H-form zeolite catalysts in this study were active and selective for DME synthesis. According to the experimental results MDHC-1 catalyst exhibited the highest activity in dehydration of methanol. After finding the most active catalyst, the H-MFI90 zeolite was modified with Na content varying from 0 to 120 mol%, via wet-impregnation method to further improve its selectivity. All of catalysts were characterized by BET, XRD, NH3-TPD, ICP, TGA, SEM, FT-IR and TPH techniques. It was found that these materials affected activity of MDHC-1 zeolite by changing its acidity. Ultimately, among all the catalysts studied, Na100-modified H-MFI90 zeolite exhibited optimum activity, selectivity and stability at methanol dehydration reaction. © 2010 Elsevier Ltd. All rights reserved.


Jafari Nasr M.R.,Iran National Petrochemical Company | Habibi Khalaj A.,Iran National Petrochemical Company | Mozaffari S.H.,Iran National Petrochemical Company
Applied Thermal Engineering | Year: 2010

This study presents an application of artificial neural networks (ANNs) to characterize thermo-hydraulic behavior of helical wire coil inserts inside tube. An experimental study was carried out to investigate the effects of four types of wire coil inserts on heat transfer enhancement and pressure drop. The experimental data sets were extracted from four wire coils which were tested within a geometrical range with helical pitch 0.156 < p / dh < 0.354 and wire diameter 0.027 < e / dh < 0.094. The investigation was conducted with transition and turbulent flow regimes with Reynolds numbers ranging from 4200 to 49,000. The experimental data sets have been utilized in training and validation of the ANN in order to predict the Nusselt numbers and friction factor inside tube with wire coil inserts, and the results were compared to the corresponding correlations. The mean relative errors (MRE) between the predicted results and experimental data were found less than 1.79% for Nusselt numbers and less than 3.27% for friction factor. The performance of the ANN was found to be superior in comparison with corresponding power-law regressions. Finally, using the ANN in order to predict the performance of thermal systems in engineering applications is recommended. Crown Copyright © 2009.

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