Search for: ethylene
Total 168 records
Consequence analysis of different ethylene oxide dispersion scenarios from storage tanks in an Iranian petrochemical complex, Article 19th International Congress of Chemical and Process Engineering, CHISA 2010 and 7th European Congress of Chemical Engineering, ECCE-7, 28 August 2010 through 1 September 2010, Prague ; 2010 ; Honarvar, B ; Rashtchian, D ; Sharif University of Technology
Ethylene oxide production units are among the most dangerous plants in the petrochemical industry. A detailed consequence analysis for different accidental scenarios for a storage tanks in a petrochemical complex in Iran is put forward. Credible scenarios were selected and all the effective factors that may influence the mechanism of release and dispersion of toxic materials were surveyed. Simulator software and numerical models were used to simulate the distribution of toxic material around the leak source. The results can be used in risk management and in providing an emergency response plan to counter unwanted situations in the plant. This is an abstract of a paper presented at the 7th...
Efficient methane conversion to hydrogen and hydrocarbons by combination of corona and glow discharge, Article Czechoslovak Journal of Physics ; Volume 54, Issue SUPPL. 3 , 2004 , Pages C990-C994 ; 00114626 (ISSN) ; Matin, N. S ; Sharif University of Technology
Kluwer Academic Publishers 2004
In this study we offer a new type of plasma which consists of double, corona and glow, discharge to convert natural gas, the main part of which is methane. The most important future of this type of plasma is the steady increase of overall chemical energy efficiency by enhancement of repetition rate. At repetition rate of R = 80 Hz, the energy efficiency of 5.5% was increased to 10% at R = 330 Hz and more improvement was yet expected at higher repetition rates. Easy control of selectivity of products that were hydrogen, acetylene, ethylene, ethane and hydrocarbons with up to 5 carbons, was also possible by repetition rate
Study on the acetylene hydrogenation process for ethylene production: simulation, modification, and optimization, Article Chemical Engineering Communications ; Volume 200, Issue 7 , Mar , 2013 , Pages 863-877 ; 00986445 (ISSN) ; Zolfaghari Sharak, A ; Mousavi, S. A ; Bakhtiari Ziabari, F ; Shariati, J ; Azizi, S ; Sharif University of Technology
In this study, an industrial acetylene hydrogenation unit is simulated utilizing three available kinetic models. The results are compared against six-day experimental data and the best model is selected. Effects of feed temperature and the amount of injected hydrogen on ethylene selectivity are also studied. According to the simulation results, the unit is not working under its optimum conditions. Furthermore, by reduction of the hydrogen flow rate to 52 kg/h, process selectivity is increased. In addition, a new approach is proposed to modify the hydrogenation process and reduce undesired by-products. In the simulation of the modified process, hydrogenation reactors temperature, hydrogen...
In vitro study of bare and poly (ethylene glycol)-co-fumarate coated superparamagnetic iron oxide nanoparticles for reducing potential risks to humans and the environment, Article Handbook of Sustainable Energy ; May , 2011 , Pages 649-666 ; 9781608762637 (ISBN) ; Simchi, A ; Imani, M ; Milani, A. S ; Stroeve, P ; Shivaee, H. A ; Sharif University of Technology
Nova Science Publishers, Inc 2011
For risk free application of nanoparticles in life science, energy and the environment, it is essential to understand their biological fate and potential toxicity. The application of iron oxide nanoparticles for drug delivery has been one of the most promising researches in the field of nanotechnology. However, there are two major problems associated with magnetically targeted deliveries that still need close attention: • As the drug is coated on to the particle surfaces, there is the possibility of faster drug release (Burst Effect). Therefore, after reaching to the specific site, there is very low amount of drug for delivery. To overcome this problem, some researchers have used conjugation...
Quantitative risk assessment for accidental release of ethylene oxide from purification column of an ethylene oxide production unit, Article CHISA 2006 - 17th International Congress of Chemical and Process Engineering, Prague, 27 August 2006 through 31 August 2006 ; 2006 ; 8086059456 (ISBN); 9788086059457 (ISBN) ; Hashemi, V ; Rashtchian, D ; Sharif University of Technology
This paper outlines a quantitative risk assessment for an 110,000 ton/day ethylene oxide production plant in Iran. After a complete and detailed hazard identification study, done by HAZOP method, the purification column was found to be one of the most hazardous sections in this plant. As ethylene oxide with high concentration and inventory is present there. Fault tree analysis (FTA) technique has been used to identify the basic events responsible for top event occurrence and also calculation of top event frequency of occurrence. Human error has been calculated numerically and probability of human error has been estimated. Failure rate data were collected referring to several sources and...
A new developed integrated process configuration for production of hydrogen chloride using geothermal and wind energy resources, Article Sustainable Energy Technologies and Assessments ; Volume 45 , 2021 ; 22131388 (ISSN) ; Ghorbani, B ; Khalili, M ; Sharif University of Technology
Elsevier Ltd 2021
Ethylene dichloride thermal cracking is one of the conventional methods for hydrogen chloride production. A critical issue concerned with this method is to provide thermal energy for cracking reaction, which is generally provided by the flammable gasses inside the furnace. Utilizing renewable energy sources can be an interesting topic in this case. Hence, in this paper, the thermal integration feasibility of an ethylene dichloride cracking unit with a hybrid renewable plant, based on geothermal and wind energies, is investigated, while the case study for wind turbines system (Alstom ECO 74/1670/ Class II model) is Meshkin Shahr, located in Iran. To utilize geothermal energy, a...
A high performance multi-walled carbon nanotube-supported palladium catalyst in selective hydrogenation of acetylene-ethylene mixtures, Article Applied Catalysis A: General ; Volume 399, Issue 1-2 , May , 2011 , Pages 184-190 ; 0926860X (ISSN) ; Kazemeini, M ; Rashidi, A. M ; Sharif University of Technology
In this research, a palladium nanocatalyst was synthesised over a multi-walled carbon nanotube (MWCNT) support and then applied for selective hydrogenation of acetylene in an ethylene-richflow stream. This material displayed a very promising selectivity toward ethylene production with increasing temperature, and also suppressed oligomer formation during acetylene hydrogenation. New operating conditions for selective hydrogenation of acetylene in an ethylene-richflow were introduced. This nanocatalyst gave a considerably higher yield, as high as 93%, than that previously obtained for ethylene production. It was postulated that the governing mechanism for acetylene hydrogenation over 0.5 wt.%...
Measurement and modeling process partitioning of cephalexin antibiotic in aqueous two-phase systems containing poly(ethylene glycol) 4000, 10000 and K2HPO4, Na3Citrate, Article Journal of Chemical and Engineering Data ; Volume 54, Issue 8 , 2009 , Pages 2239-2244 ; 00219568 (ISSN) ; Pazuki, G. R ; Taghikhani, V ; Vossoughi, M ; Ghotbi, C ; Sharif University of Technology
In this work, the partition coefficients of Cephalexin in aqueous two-phase systems containing PEG [poly(ethylene glycol)] 4000, 10000 and K 2HPO4, Na3Citrate (C6H 5Na3O7 5, 5H2O) have been measured. The experimental data were obtained in a wide range of temperatures, (28.2 to 37.2) °C. The effects of temperature, pH, polymer concentration, polymer molecular weight, and salt concentration on the partitioning of Cephalexin were also studied. The results showed that salt concentration has a large effect on the partition coefficient, and temperature has an almost negligible effect. The Chen-NRTL Gibbs energy model was used to correlate the experimental results. © 2009 American Chemical Society
Study of gas separation properties of ethylene vinyl acetate (EVA) copolymer membranes prepared via phase inversion method, Article Separation and Purification Technology ; Volume 62, Issue 3 , 22 September , 2008 , Pages 642-647 ; 13835866 (ISSN) ; Sadeghi, M ; Motamed Hashemi, M. M. Y ; Pourafshari Chenar, M ; Roosta Azad, R ; Sadeghi, M ; Sharif University of Technology
The gas separation properties of ethylene vinyl acetate (EVA) membranes containing 18 and 28 wt% of vinyl acetate (VA) were investigated in this study. The effects of membrane preparation conditions, such as thermal and thermal/wet phase inversion, and the type of solvent on the gas separation properties of EVA membranes were investigated. The permeation of pure O2, N2, CH4, and CO2 gases at different feed pressures ranging from 2 to 11 bar were examined. The results indicated that the CO2 permeability was evidently higher than those of the other gases. Furthermore, the solubility mechanism was found to be the dominant mechanism for permeation of gases through EVA membranes. Moreover, the...
M.Sc. Thesis Sharif University of Technology ; Shojaei, Akbar ; Sheikh, Nasrin
Polyethylene (PE) is used as an insulation material for wires and cables because of its excellent electrical properties. For such application, it can be exposed to the high energy irradiation such as gamma ray and electron beam (EB), making possible crosslinking of the PE. Most of the properties of PE are improved greatly after irradiation, but it was harden and split easily. Due to the flexibility of EVA, depending on the vinyl acetate content, it can improve the toughness of the LDPE significantly upon addition to this polymer. As a result, radiation induced LDPE/EVA blend has been a good candidate for the wire and cable insulation. Also, upon addition of a few amount of OC, different...
Rheological Characterization of Nanocomposite Alloy of Polyethylene/ Polyethylene Vinyl Acetate and Nano Cla, M.Sc. Thesis Sharif University of Technology ; Ramazani Saadatanadi, Ahmad
In this thesis, polyethylene vinyl acetate and polyethylene shrinkable nanocomposite films with different percentages of an organoclay such as 0, 1, 3, 5 and 7% have been prepared via two-steps solution method. Morphological and properties of these films, including permeability and mechanical and rheological properties were investigated. Also the effect of addition of cross linking agent (DCP) was studied. Various tests including XRD, SEM, tensile and rheological properties were studied. XRD tests showed that the distance between a layer of or ganoclay increased to 32 percent. This indicates that the polymer chains between the layers of organoclay could be better. SEM examination showed that...
M.Sc. Thesis Sharif University of Technology ; Samadfam, Mohammad
At a unit in zirconium production plant under the supervision of Soure Co. nuclear grade zirconium is produced. In the process it is required that hafnium get separated from Zirconium. Zirconium and hafnium separation are performed by nitric acid (4N) and hydrochloric acid (4N). This isolation environment is considerably corrosive and damaging for the equipment. Powder coating is one of the solutions to deal with the corrosion. To do so, electrostatic powder coating method was used for ECTFE polymer. After the coating, according to spark test, roughness analysis, thickness, elasticity and adhesion; temperature and time of the spraying and the spraying of top coating was determined. In...
A Theoretical Investigation of Adsorption Energy of a Simple Reaction of FTS by Density Functional Theory (DFT), M.Sc. Thesis Sharif University of Technology ; Gholami, MohammadReza ; Alahyfard, MohammadReza
The advent and advancement of technology through the conversion of Gas-Synthesis (a mixture of CO and H) into liquid hydrocarbons, by Fischer- Tropsch synthesis (FTS) gives more promising future in this field. Metals such as cobalt, nickel, zinc and iron are used as catalysts for FTS. Studies have shown that the surface structure of metal catalyst has a great influence on the process, and leads to different products and transition states. Iron has been known the most used and the most cost-effective metal catalyst in FTS. Different surfaces of Iron have different catalytic roles. In our work, Fe(100) -that is the most stable after Fe(110) and is known as the most active iron’s surface in...
Synthesis of new modified MCM-41/PSF nanocomposite membrane for improvement of water permeation flux, Article Desalination and Water Treatment ; Volume 41, Issue 1-3 , 2012 , Pages 53-61 ; 19443994 (ISSN) ; Shafiee, A ; Moradian, A ; Sharif University of Technology
The preparation of MCM-41 nanoparticles was made using tetraethylorthosilicate as silica source and cetyltrimethylammonium bromide as surfactant. The X-ray diffraction, transmission electron microscopy, laser particle size analysis and N2 adsorption techniques were used for characterization of nanoparticles. The dimethyldichlorosilan (DMDCS) was applied to improve the dispersion of MCM-41 nanoparticles into the polysulfone (PSF) matrix. The investigation on the thermal stability with thermogravimetric analysis showed the enhanced stability of membranes possessing higher loading of MCM-41 nanaoparticles. The scanning electron microscopy was used to evaluate the quality of particles dispersion...
Synthesis and characterization of novel 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo dodecane based nanopolymer-bonded explosives by microemulsion, Article Journal of Molecular Liquids ; Volume 206 , June , 2015 , Pages 190-194 ; 01677322 (ISSN) ; Soleyman, R ; Zarandi, M ; Sharif University of Technology
2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo dodecane (CL-20)-based polymer/plastic bonded explosives are used in propellant formulation. It can be predicted that CL-20-based nano-polymer/plastic bonded explosives are able to have reduced composite sensitivity and superior mechanical strength. In the current study, we have prepared two kinds of CL-20-based nano-polymer/plastic bonded explosives with ethylene-vinyl acetate copolymer and glycidyl azide polymer via the microemulsion method. Several visual techniques such as SEM/AFM/TEM techniques have been utilized for complete characterization of CL-20-based...
Renewable hydrogen production by ethylene glycol steam reforming over Al2O3 supported Ni-Pt bimetallic nano-catalysts, Article Renewable Energy ; Volume 128 , 2018 , Pages 188-199 ; 09601481 (ISSN) ; Khorasheh, F ; Sharif University of Technology
The steam reforming of ethylene glycol, a simple model compound for biomass-derived liquids, is considered to be an environmentally green process for producing renewable hydrogen. Both Pt and Ni species are known for their catalytic activity under steam reforming reaction conditions. In this investigation, alumina supported Ni-Pt bimetallic catalysts (X wt% Ni-Y wt% Pt/Al2O3 named XNi-YPt) were employed for steam reforming of ethylene glycol. The prepared catalysts were characterized by XRD, BET, H2-TPR, H₂-Chemisorption, and TEM. It was observed that Ni/Pt ratio strongly affected the redox behavior, BET surface area, and particle size of the samples that in turn affected their catalytic...
Effect of ethylene-vinyl acetate copolymer on the rheological behaviour of alumino-silicate/polyethylene wax suspensions, Article Ceramics International ; Volume 28, Issue 5 , 2002 , Pages 507-514 ; 02728842 (ISSN) ; Taheri Nassaj, E ; Davami, P ; Sharif University of Technology
Ceramic suspensions were prepared from an alumino-silicate powder, polyethylene wax (PE-wax) as binder with additions of stearic acid (SA). The ceramic powder consisted of mullite, corundum and tridymite phases. The organic binders contained 3 to 8 wt.% ethylene-vinyl acetate (EVA) and were filled with various volume fractions of ceramic powder. The yield stresses of suspensions were estimated using shear stress-shear rate data measured at 90-120 °C. The addition level of EVA was shown to have a considerable effect on the yield stress of suspensions. The effect of EVA on the flow parameters was also investigated over the temperature range of 90 to 120 °C. It was shown that the addition of 5...
Study the Effects of Components Ratio on Microstructure and Mechanical Properties of Polyethylene Ternary Blend (HDPE/LLDPE/LDPE), M.Sc. Thesis Sharif University of Technology ; Bagheri, Reza
Melt blending of polymers is a rather cheap and easy approach for obtaining new set of properties compared to synthesizing new polymeric materials. For the same reason, binary and ternary polyethylene blends are made to provide added value for different applications. Polyethylene blends are commonly composed of high density polyethylene (HDPE), low density polyethylene (LDPE) and linear low density polyethylene (LLDPE). Although the Mechanical and physical properties of polyethylene binary blends have been studied extensively, microstructure and mechanical properties of polyethylene ternary blends have been the subject of very few studies. In this work, samples with 40-60 Wt. % HDPE and...
Article Chemical Engineering and Technology ; Volume 36, Issue 10 , 2013 , Pages 1691-1700 ; 09307516 (ISSN) ; Kazemeini, M ; Khorasheh, F ; Darvishi, A ; Rashidi, A. M ; Sharif University of Technology
An industrial-scale reactor for ethylene production was modeled using the oxidative dehydrogenation of ethane (ODHE) in a multi-tubular reactor system, examining a variety of parameters affecting reactor performance. The model showed that a double-bed multi-tubular reactor with intermediate air injection scheme was superior to a single-bed design, due to the increased ethylene selectivity while operating under lower oxygen partial pressures. The optimized reactor length for 100% oxygen conversion was theoretically determined for both reactor designs. The use of a distributed oxygen feed with a limited number of injection points indicated a significant improvement on the reactor performance...
Article Petroleum Science and Technology ; Volume 31, Issue 6 , Feb , 2013 , Pages 596-602 ; 10916466 (ISSN) ; Fakhrhoseini, S. M ; Ghiassi, H ; Sharif University of Technology
The bulk of the worldwide annual commercial production of ethylene is based on thermal cracking of petroleum hydrocarbons with steam. In this research, the effect of coil outlet temperature on the reactor yield has been studied. In order to investigate a reliable mathematical correlation, several data points were obtained by adjusting coil outlet temperature in a real plant. In order to investigate best coil outlet temperature, an objective function was represented. Based on the obtained mathematical correlation and the assumed objective function, it was found that best coil outlet temperature for investigating maximum income is 1,128 K