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Screening plaintiffs and selecting defendants in medical malpractice litigation: evidence from Illinois and Indiana
, Article Journal of Empirical Legal Studies ; Volume 15, Issue 1 , March , 2018 , Pages 41-79 ; 17401453 (ISSN) ; Hyman, D. A ; Black, B ; Liu, J ; Silver, C ; Sharif University of Technology
Blackwell Publishing Inc
2018
Abstract
Many physicians and tort reform advocates believe that most medical malpractice (med mal) claims are “frivolous.” As evidence, they often rely on reports that only about 20 percent of claims result in a payout. Many physicians and reform advocates also believe that plaintiffs lawyers often sue every health provider with even a remote a connection to the patient. Plaintiffs’ lawyers, however, insist that they screen med mal cases carefully, and when they bring a claim, are selective in whom they sue. Can these perspectives be harmonized? We study this question using databases of every insured med mal claim closed in Illinois during 2000–2010 and in Indiana during 1980–2015, and with...
Exergy and exergoeconomic analysis of hydrogen and power cogeneration using an HTR plant
, Article Nuclear Engineering and Technology ; Volume 53, Issue 8 , 2021 , Pages 2753-2760 ; 17385733 (ISSN) ; Talebi, S ; Fani, M ; Khajehpour, H ; Sharif University of Technology
Korean Nuclear Society
2021
Abstract
This paper proposes using sodium-cooled fast reactor technologies for use in hydrogen vapor methane (SMR) modification. Using three independent energy rings in the Russian BN-600 fast reactor, steam is generated in one of the steam-generating cycles with a pressure of 13.1 MPa and a temperature of 505 °C. The reactor's second energy cycles can increase the gas-steam mixture's temperature to the required amount for efficient correction. The 620 ton/hr 540 °C steam generated in this cycle is sufficient to supply a high-temperature synthesis current source (700 °C), which raises the steam-gas mixture's temperature in the reactor. The proposed technology provides a high rate of hydrogen...
Comparative study of conventional steam-methane-reforming (SMR) and auto-thermal-reforming (ATR) with their hybrid sorption enhanced (SE-SMR & SE-ATR) and environmentally benign process models for the hydrogen production
, Article Fuel ; Volume 297 , 2021 ; 00162361 (ISSN) ; Tanveer, H. U ; Abbas, S. Z ; Maqbool, F ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
The paper presents a comparison of steam methane reforming (SMR), sorption enhanced steam methane reforming (SE-SMR), auto-thermal reforming (ATR), and sorption enhanced auto-thermal reforming (SE-ATR) in a fixed bed reformer for hydrogen production. A one-dimensional, unsteady-state heterogeneous reactor model for each process which includes mass and thermal dispersion in the direction of flow and axial pressure distribution, has been simulated using gPROMS® 4.0.1 model builder, while CEA and Aspen Plus® have been employed to analyze the equilibrium performance and simulate the process flowsheets of individual process respectively. The performance of the individual hydrogen production...
Catalyst deactivation in industrial combined steam and dry reforming of natural gas
, Article Fuel Processing Technology ; Vol. 120 , 2014 , pp. 96-105 ; ISSN: 03783820 ; Baghalha, M ; Sharif University of Technology
Abstract
The catalyst's performance and deactivation in a Midrex® industrial fixed bed reactor were investigated for the combined steam and dry reforming of natural gas using a one-dimensional heterogeneous model. The results demonstrate that there is a strong tendency for the catalyst's deactivation by carbon formation originating from methane decomposition. However, kinetic modelling of the combined reforming process shows that only a fraction of the catalyst in the industrial reactor is required for the reactions to reach an equilibrium state in the reformer. Hence, as the catalyst is deactivated at the reactor entrance area, the reaction zone gradually moves forward and still allows for...
Developing a mathematical model for reforming of glycerol towards a comparative evaluation of the liquid vs. gas phase medium
, Article International Journal of Hydrogen Energy ; Volume 44, Issue 49 , 2019 , Pages 26764-26772 ; 03603199 (ISSN) ; Kazemeini, M ; Larimi, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Glycerol might be converted into hydrogen through a catalytic reforming process. In order to design an effective route, the choice of reaction conditions and in particular its medium considered yet a crucial issue still needing further investigations. In this research, a mathematical model of reforming processes in vapor (i.e., steam reforming (SR) and liquid phase (i.e.; aqueous phase reforming (APR)) were developed. This was performed in terms of understudying effects of parameters including the reactor diameter, catalyst morphology (i.e., particle size) and mass flow rate on the glycerol conversion. Then, a superior reaction medium in terms of these variables was determined. For data...
Modeling of sorption enhanced steam methane reforming in an adiabatic packed bed reactor using various CO2 sorbents
, Article Journal of Environmental Chemical Engineering ; Volume 9, Issue 5 , 2021 ; 22133437 (ISSN) ; Abbas, S. Z ; Maqbool, F ; Ramirez Solis, S ; Dupont, V ; Mahmud, T ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
A 1-D heterogeneous model of sorption-enhanced steam methane reforming (SE-SMR) process in a packed bed reactor consisting of nickel catalyst well mixed with CO2 sorbent particles is investigated for three types of common sorbents. The performance of SE-SMR process is studied under low medium pressure conditions (3 – 11 bar) to find the optimum operating conditions. Optimal CaO sorption corresponding to 82% CH4 conversion and 85% H2 purity is found at 900 K, 3 bar, 3.5 kgm−2s−1 and S/C of 3.0. In contrast, lithium zirconate (LZC) and hydrotalcite (HTC) sorbents exhibited best sorptions under the operating conditions of 773 K, 5 bar and S/C of 3 with CH4 conversion of 91.3% and 55.2%, and H2...
Exergy analysis of waste heat recovery section in steam-natural gas reforming process
, Article Energy and Fuels ; Volume 29, Issue 5 , April , 2015 , Pages 3322-3327 ; 08870624 (ISSN) ; Farhadi, F ; Sharif University of Technology
American Chemical Society
2015
Abstract
In this work, an exergy analysis is performed for the waste heat recovery section (WHRS) of the steam-natural gas reforming (SNGR) process as a major energy intensive process. Two alternate conditions are investigated to evaluate the required thermodynamic parameters: normal operating condition and increase of C2 + components in the process feed stream. At normal operating condition, the exergy efficiency of WHRS amounts to 0.58 while some 17.2 kJ energy is destructed for each mole of H2 produced. If heavier than methane components are increased in the feed up to 8.5 mole %, despite the increase of H2 production, the exergy efficiency decreases down to 0.54...
Renewable hydrogen production over Pt/Al₂O₃ nano-catalysts: Effect of M-promoting (M=Pd, Rh, Re, Ru, Ir, Cr)
, Article International Journal of Hydrogen Energy ; Volume 44, Issue 16 , 2019 , Pages 8243-8251 ; 03603199 (ISSN) ; Khorasheh, F ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Xwt% Pt/Al 2 O 3 (X = 1, 3, 5, 8, 10) and 5 wt% Pt-1wt% M/AlO 3 (M = Pd, Rh, Re, Ru, Ir, Cr) catalysts were prepared, characterized and tested for aqueous phase reforming of pure and crude glycerol. Results show drastic dependence of catalytic performance of catalysts on both the active metal loading and the type of applied promoters. 5 wt% was the best Pt loading and Pt[sbnd]Rh/Al₂O₃ shows the best catalytic activity which has the highest hydrogen production rate (mmol/g cat h −1 ) and selectivity (89%) in continuous aqueous phase reforming of 10 wt% pure glycerol solution
Simulation of Complex and Dry Reforming of Natural Gas to Produce Synthesis Gas And Their Technical and Economical Comparison
, M.Sc. Thesis Sharif University of Technology ; Kazemeini, Mohammad (Supervisor) ; Zamanian, Akbar (Supervisor) ; Baghalha, Morteza (Supervisor)
Abstract
In this study, two units of production of synthesis gas has been stimulated into 2 forms of natural gas complex (steam/Co2¬) reforming and dry reforming. They have been examined from technical and economical views. The product from this process is synthesis gas by the unit ratio of Hydrogen and Carbon Monoxide which is used in Arak petrochemical complex for producing 2EH. For producing this synthesis gas in 900C (reactor temperature) and 15 bar of total pressure , the ratio of feeding parts into reforming reactor for total input carbon (methane and other hydrocarbon) and Carbon dioxide gas and water vapor in representation ( [CH4 + other hydrocarbons : CO2 : H2O ] ) for complex reforming ...
Aqueous Phase Reforming of Biomass Using Micro-reactor
, M.Sc. Thesis Sharif University of Technology ; Kazemeini, Mohammad (Supervisor) ; Mohammadi, Aliasghar (Supervisor)
Abstract
Consumption of oil and gas as energy carrier leads to irreversible environmental effects related to greenhouse gases emission. Hence, for the reduction in greenhouse gas emission, a shift to renewable resources for energy supply is recommended. However, in recent years, hydrogen has emerged as the most promising clean energy carrier for generating electrical power through fuel cells. Nevertheless, production of renewable hydrogen is the main barrier to the development of hydrogen as an energy carrier. Aqueous phase reforming of oxygenated hydrocarbon is developed by Dumesic for producing renewable hydrogen-rich gas with low CO. Since it is expected that, use of new technology such as the...
Coke formation possibility during production of reducing gas in large scale direct reduction plant
, Article Ironmaking and Steelmaking ; Volume 34, Issue 2 , 2007 , Pages 115-123 ; 03019233 (ISSN) ; Vakhshouri, K ; Hashemi, M. M. Y. M ; Sharif University of Technology
2007
Abstract
For the production of synthesis gas utilised in Midrex direct reduction plants, catalytic steam/CO2 hydrocarbon reforming in tubular reformer is the major process. Owing to the high heat input through the Midrex reformer tube wall, the endothermic nature of reforming reactions, low mass velocity of feed gas and large tube diameter, the catalyst bed is exposed to considerable axial and radial temperature gradients. These radial concentration and temperature gradients may create local areas with potential for carbon formation. To investigate this phenomenon, a rigorous two-dimensional model is developed for simulating the operation of a Midrex reformer which applies a dual catalyst loading...
Coke Deposition Process in Nano-Pores of Naphtha Reforming Catalyst
, M.Sc. Thesis Sharif University of Technology ; Baghalha, Morteza (Supervisor) ; Kazemeini, Mohammad (Supervisor)
Abstract
Nowadays catalytic reforming of naphtha is one of the most important parts of the refining process. The catalyst of this process is mostly Pt-Re on the γ-alumina support. The major cause of deactivation is coke deposition and blockage of the pores as a result. Meanwhile, modeling of the process and the deactivation of catalyst would help refining industries to achieve higher yields. In this study industrial data of the catalytic reforming unit #2 in Isfahan Refinery Plant were used to model the process, optimized parameters have been calculated and the best contribution of the catalyst among the four reactors was presented. Then with using a deactivation function the whole coking...
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
Abstract
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...
Propane steam reforming on mesoporous NiO–MgO–SiO2 catalysts for syngas production: Effect of the MgO/SiO2 molar ratio
, Article International Journal of Hydrogen Energy ; Volume 45, Issue 46 , 2020 , Pages 24840-24858 ; Kazemeini, M ; Rezaei, M ; Farhadi, F ; Keshavarz, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this research, a series of NiO-xMgO-SiO2 catalysts with various MgO/SiO2 molar ratios were prepared via precipitation method followed by a hydrothermal treatment in the presence of PVP as surfactant. The synergic effect between MgO and SiO2 leading to the various characteristic and catalytic performance during propane steam reforming was investigated in detail. The results showed that 15 wt% NiO-0.5MgO–SiO2 catalyst possessed the highest catalytic activity (68.9% conversion for C3H8 at 550 °C) with a negligible amount of carbon formation after 20 h of reaction duration. This superior catalytic performance can be attributed to the enhanced basicity strength along with strong metal-support...
Comparative process modeling and techno-economic evaluation of renewable hydrogen production by glycerol reforming in aqueous and gaseous phases
, Article Energy Conversion and Management ; Volume 225 , December , 2020 ; Larimi, A ; Khorasheh, F ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this paper, a comparative techno-economic evaluation of hydrogen production by glycerol reforming in aqueous and gaseous phases are presented. To accomplish the techno-economic evaluation, firstly the process modeling and design are presented. Based on the equipment purchased costs, with 80 kg/h hydrogen production, the total cost of hydrogen production is estimated 3.65 and 3.55 $/kgH2 for steam reforming and aqueous phase reforming plants, respectively. Regarding the installation factor in the equipment costs, the total cost of hydrogen production is estimated 7.49 and 7.45 $/kgH2 for steam reforming and aqueous phase reforming plants, respectively. To investigate the impact of...
Catalytic conversion of bio-renewable glycerol to pure hydrogen and syngas: Energy management and mitigation of environmental pollution
, Article Energy Conversion and Management ; Volume 247 , 2021 ; 01968904 (ISSN) ; Lotfi Varnoosfaderani, M ; Moghadasin, M. H ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Hydrogen and syngas, as two effective clean fuels, have a considerable stake in the global fuel market. These are dominantly produced from fossil fuels through reforming processes, which lose a large amount of energy and emit numerous amounts of CO2. Bio-renewable glycerol steam reforming is an attractive alternative to traditional reforming for reducing the dependence on hydrocarbon resources and mitigating climate change. This research aims to manage a heat-integrated reactor with three concentric cylinders, containing exothermic-side (methane tri-reforming), endothermic-side (glycerol steam reforming), and permeation-side for co-production of pure hydrogen and syngas. In this process,...
Effect of rare-earth promoters (Ce, La, Y and Zr) on the catalytic performance of NiO-MgO-SiO2 catalyst in propane dry reforming
, Article Molecular Catalysis ; Volume 522 , 2022 ; 24688231 (ISSN) ; Rezaei, M ; Kazemeini, M ; Farhadi, F ; Keshavarz, A. R ; Sharif University of Technology
Elsevier B.V
2022
Abstract
In this contribution, NiO-MgO-SiO2 catalysts containing 3 wt. % of CeO2, La2O3, Y2O3, and Zr2O3 were examined for propane dry reforming at 550-750 °C. The samples were synthesized by a co-precipitation route, followed by a hydrothermal treatment, and characterized by BET, XRD and TPX analyses. The results indicated that the addition of promoters enhanced the metal-support interaction and basic characteristics, while the acidic nature of the promoted catalyst was changed in a different way. The highest propane conversion of 39.6% was observed over Ce-promoter sample, while the un-promoted catalyst possessed a value of 36.8% at 700 °C. Nevertheless, La and Y-promoted catalysts possessed a...
Kinetic Modeling of Glycerol Aqueous Phase Reforming Process
, M.Sc. Thesis Sharif University of Technology ; Kazemeini, Mohammad (Supervisor)
Abstract
Dwindling fossil fuel reserves with attendant rising crude oil price and the relatively rapid growth in global population have made the search for sustainable energy supply more imperative. Among the various renewable resources, biomass has attract much more attention. Glycerol as the major by-product of the biodiesel production process, can be converted to hydrogen. One of the methods for converting glycerol to hydrogen is aqueous phase reforming (APR). In the current research, glycerol aqueous phase reforming is modeled and then simulated with MATLAB software. The reactor diameter is 5 mm and its length is 20 cm and reactor operated at 250℃ and 50 bar. Glycerol conversion obtained is...
Influence of metal loading and reduction temperature on the performance of mesoporous NiO–MgO–SiO2 catalyst in propane steam reforming
, Article Journal of the Energy Institute ; Volume 96 , 2021 , Pages 38-51 ; 17439671 (ISSN) ; Farhadi, F ; Rezaei, M ; Kazemeini, M ; Keshavarz, A ; Sharif University of Technology
Elsevier B.V
2021
Abstract
In this research, a series of NiO–MgO–SiO2 catalyst samples with various nickel contents (5, 10, 15 and 20 wt %) were prepared by a co-precipitation method followed by a hydrothermal treatment and employed in propane steam reforming. The analyses revealed that the enhancement of the nickel content up to 15 wt % improved the propane conversion to 98.6% at 550 °C. Nonetheless, further increase in the nickel loading reduced the catalyst activity due to the formation of larger and more poorly dispersed active sites. Besides, 15 wt % nickel loading led to the high resistance against coke deposition with no detectable carbon on the catalyst surface. In addition, it was revealed that, the decrease...
Syngas production through CO2 reforming of propane over highly active and stable mesoporous NiO-MgO-SiO2 catalysts: Effect of calcination temperature
, Article Fuel ; Volume 322 , 2022 ; 00162361 (ISSN) ; Kazemeini, M ; Rezaei, M ; Farhadi, F ; Keshavarz, A. R ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
In this contribution, NiO-MgO-SiO2 catalyst was prepared and calcined at different temperatures of 500, 600, 700 and 800 °C. The resulting samples were characterized by BET-BJH, XRD, TPX, CO-chemisorption, EDS and SEM analyses. These were employed toward syngas production via propane dry reforming. The increment in the calcination temperature from 500 to 800 °C decreased the basicity of the catalysts. In addition, the active surface area and Ni dispersion were gradually declined by increasing the calcination temperature from 600 to 700 °C due to active metal sintering during the activation process. The calcined sample at 600 °C displayed the highest propane and CO2 conversions of 93% and 78%...