Introduction of Novel Process for Sweetening of Sour Crude Oil: Optimization of Process

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Farshad Farahbod ◽  
Sara Farahmand
Keyword(s):  
Cost Estimation ◽  
Sulfur Removal ◽  
Particle Diameter ◽  
Packed Bed ◽  
Optimum Conditions ◽  
Interfacial Velocity ◽  
Process Characterization ◽  
Sour Crude ◽  
The Subject ◽  
Temperature And Pressure

The subject of this experimental report is the application of nanoparticles in petroleum refining. Sulfur removal from petroleum using carbon nanotubes is considered in this study. The properties related to the process characterization are measured experimentally and reported. The effect of low range temperature and pressure, initial concentration, interfacial velocity, the ratio of height to diameter of the bed and particle diameter on the outlet sulfur is investigated. Design of experiment is performed to show which of the controllable parameters affects the sulfur removal process and a predictive model is developed. Optimization of the model is performed with the aim that the outlet sulfur content less than 0.6 ppm is achievable. Also, the increase in the amount of pollutant higher than 50 ppm sulfur and increase in the amount of superficial velocity higher than 0.4 m/s lead the adsorption process to the improper results. Finally, cost estimation due to pressure and temperature is presented and the optimum conditions of 1.7 atm pressure and 35 °C temperature with the height to diameter ratio of three and nano carbon tubes of 50 nm for packed bed are proposed.

The Effect of Turbulence on Momentum and Heat Transport in Packed Beds with Low Tube to Particle Diameter Ratio

2018 ◽  
Vol 16 (11) ◽  
Author(s):  
F. I. Molina-Herrera ◽  
C. O. Castillo-Araiza ◽  
H. Jiménez-Islas ◽  
F. López-Isunza
Keyword(s):  
Thermal Conductivity ◽  
Heat Transport ◽  
Mass Flux ◽  
Flow Model ◽  
Particle Diameter ◽  
Packed Bed ◽  
Diameter Ratio ◽  
Packed Beds ◽  
Measured Temperature ◽  
Orthogonal Collocation

Abstract This is a theoretical study about the influence of turbulence on momentum and heat transport in a packed-bed with low tube to particle diameter ratio. The hydrodynamics is given here by the time-averaged Navier-Stokes equations including Darcy and Forchheimer terms, plus a κ-ε two-equation model to describe a 2D pseudo-homogeneous medium. For comparison, an equivalent conventional flow model has also been tested. Both models are coupled to a heat transport equation and they are solved using spatial discretization with orthogonal collocation, while the time derivative is discretized by an implicit Euler scheme. We compared the prediction of radial and axial temperature observations from a packed-bed at particle Reynolds numbers (Rep) of 630, 767, and 1000. The conventional flow model uses effective heat transport parameters: wall heat transfer coefficient (hw) and thermal conductivity (keff), whereas the turbulent flow model includes a turbulent thermal conductivity (kt), estimating hw via least-squares with Levenberg-Marquardt method. Although predictions of axial and radial measured temperature profiles with both models show small differences, the calculated radial profiles of the axial velocity component are very different. We demonstrate that the model that includes turbulence compares well with mass flux measurements at the packed-bed inlet, yielding an error of 0.77 % in mass flux balance at Rep = 630. We suggest that this approach can be used efficiently for the hydrodynamics characterization and design and scale-up of packed beds with low tube to particle diameter ratio in several industrial applications.

scholarly journals Suburban Rail in the Podkarpackie Voivodeship as a Factor Stimulating the Development in the Region

2020 ◽  
Vol 2020 (2) ◽  
pp. 28-36
Author(s):  
Beata Gierczak-Korzeniowska ◽  
Keyword(s):  
Cost Estimation ◽  
Rail Transport ◽  
Railway Transport ◽  
Suburban Areas ◽  
The People ◽  
Commute Time ◽  
Marketing Analysis ◽  
The Subject ◽  
Transport Problems ◽  
Clear Increase

Over the last few years, there has been a clear increase in interest in rail transport among local authorities, especially the agglomeration rail. A particular emphasis in this respect is being observed in large agglomerations and the surrounding suburban areas, where transport problems are becoming increasingly frequent. The fact that the number of passengers of agglomeration and regional railways in Poland is growing gives a positive overtone to the issue in question. The project of creating a system of Suburban Rail in the Podkarpackie Voivodeship is to significantly affect the development of the region. A reduction in commute time, the improvement of the transport offer and the increase in the accessibility to rail transport in Rzeszów area and thus the improvement of mobility of the society are some of the advantages of the investment. The project will encompass municipalities located within railway lines running from Dębica to Przeworsk and from Kolbuszowa to Strzyżów. The aim of the article is to present general assumptions of the project and to estimate the benefits resulting from the project for the region and its inhabitants. The research methodology and data sources consist mainly of an analysis of the documents concerning the Feasibility Study for the project The Construction of Suburban Rail obtained from the Marshal's Office in Rzeszów, with particular emphasis on Stage II - A marketing analysis of investment variants and Stage III – A technical analysis of all investment variants of the project together with cost estimation. The basis of the study also included research of the subject literature and interviews with the people responsible for project implementation. Keywords: Suburban Rail; regional development; railway transport; Podkarpackie voivodeship

scholarly journals Gas-liquid flows through porous media in microgravity: Packed Bed Reactor Experiment-2

2021 ◽  
Author(s):  
Brian Motil ◽  
Mahsa Taghavi ◽  
Vemuri Balakotaiah ◽  
Henry Nahra
Keyword(s):  
Gas Flow ◽  
Liquid Velocity ◽  
Space Station ◽  
Particle Diameter ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Flow Rates ◽  
Test Conditions ◽  
Superficial Gas Velocity ◽  
Liquid Flows

Experimental results on pressure drop and gas hold-up for gas-liquid flow through packed beds obtained from a second flight on the International Space Station are presented and analyzed. It is found that the gas hold-up is a function of the bed history at low liquid and gas flow rates whereas higher gas hold-up and pressure gradients are observed for the test conditions following a liquid only pre-flow compared to the test conditions following a gas only pre-flow period. Over the range of flow rates tested, the capillary force is the dominant contributor to the pressure gradient and is found to be linear with the superficial liquid velocity but is a much weaker function of the superficial gas velocity. The capillary contribution is also a function of the particle size and varies approximately inversely with the particle diameter within the range of the test conditions.

Experimental Investigation of Convective Melting of Granular Packed Bed Under Microgravity

2000 ◽  
Author(s):  
J. Jiang ◽  
Y. Hao ◽  
Y.-X. Tao
Keyword(s):  
Experimental Investigation ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Vertical Direction ◽  
Packed Bed ◽  
Melting Rate ◽  
Control Flow ◽  
Solid Particles ◽  
Average Particle ◽  
Ice Particles

Abstract To improve the understanding of convective melting of packed solid particles in a fluid, an experimental investigation is conducted to study the melting characteristics of a packed bed by unmasking the buoyancy forces due to the density difference between the melt and solid particles. A close-loop apparatus, named the particle-melting-in-flow (PMF) module, is designed to allow a steady state liquid flow under a specified temperature. The module is on board NASA’s KC-135 reduced gravity aircraft for the experiments. In the test module, water is used as the fluid, and ice particles are fed to the test section at the beginning of the test. As the liquid flows though the bed, the solid grains melt. A perforate plate, through which liquid can flow while the ice particles are retained, bounds the downstream of the packed bed. From the digital video images the local packed bed thickness is measured under control flow rate, and the melting rate is determined. The temperature distribution along the horizontal direction and vertical direction is measured using 19 thermocouples. An infrared camera is mounted to record the local temperature variation between liquid and solid. The melting rates are presented as a function of upstream flow velocity, temperature and initial average particle size of the packed bed. It is found that the melting rate is influenced mainly by the ratio of the Reynolds number (Re, based on the initial particle diameter) to the square of the Froud number (Fr), and me Stefan number (Ste). In general, the dimensionless melting rate decreases as Re/Fr2 increases and increases as Ste increases. With the absence of gravity, i.e., Froud number approaches infinity, a maximum melting rate can be achieved for otherwise the same test conditions. The increase in the melting rate with the increase in Stephan number also becomes more pronounced under the zero gravity condition.

Lipase Acrylic Resin Catalyzed Interesterification of Sewage Sludge in Micro Packed Bed Reactor: Box-Behnken Design

2020 ◽  
Vol 870 ◽  
pp. 81-96
Author(s):  
Ali A. Jazie ◽  
Riyam Imad Jaddan ◽  
Mohamed F. Al-Dawody ◽  
Suhad A. Abed
Keyword(s):  
Enzyme Activity ◽  
Sewage Sludge ◽  
Ethyl Acetate ◽  
Acrylic Resin ◽  
Packed Bed ◽  
Biodiesel Production ◽  
Packed Bed Reactor ◽  
Heating Process ◽  
Optimum Conditions ◽  
Box Behnken Design

Ethyl acetate as acyl accepter have been used for sewage sludge biodiesel production in micro packed bed reactor. Lipase acrylic resin enzyme activity was investigated in the interesterification reaction of converting the sewage sludge into a biodiesel product. The main parameters affecting the process was adjusted via the design of Box-Behnken and approach of response surface then the optimum conditions were as follow (reaction time=15 h, ethyl acetate/oil ratio=24:1, temperature=40 °C and enzyme quantity=18 wt%) providing 95.78 % biodiesel yield. The lipase acrylic resin was examined under the optimum conditions for the reusability. the flow effect and the heating process of the micro packed bed reactor was investigated. The product biodiesel physicochemical properties were evaluated according to the ASTM D-6751-2 and found acceptable comparable to the mineral diesel properties.

Optimum Conditions for the Operation of Airline Aircraft

1953 ◽  
Vol 57 (512) ◽  
pp. 524-527 ◽  
Author(s):  
Alan H. Stratford
Keyword(s):  
Conventional Method ◽  
Direct Costs ◽  
Profit Margin ◽  
Optimum Conditions ◽  
Transport Aircraft ◽  
The Subject ◽  
Aircraft Type ◽  
The Individual ◽  
Insight Into

The Conventional method of assessing the direct costs or the aircraft type costs on a passenger mile or ton mile basis does not necessarily give a sufficient indication of the economic merit of a particular type of transport aircraft. It can be misleading when comparing aircraft of widely different design, and it does not indicate the best routes for effective airline exploitation.The profit margin in relation to the fundamental cost or investment unit of the individual airline must be the ultimate yardstick of transport aircraft selection and this is here analysed with a view to providing further insight into the optimum conditions for potential profits. This study of the subject draws attention to the primary factors involved and suggests a criterion which can be simplified into a form valid for most airline economies.

On the Incipient Fluidized State of Solid Particles

1993 ◽  
Vol 58 (6) ◽  
pp. 1213-1241 ◽  
Author(s):  
Miloslav Hartman ◽  
Robert W. Coughlin
Keyword(s):  
Fixed Bed ◽  
Packed Bed ◽  
Solid Particles ◽  
Minimum Fluidization Velocity ◽  
Fluidization Velocity ◽  
Minimum Fluidization ◽  
Turbulent Flow Regime ◽  
Temperature And Pressure ◽  
Particle Size And Shape ◽  
Comprehensive Study

A comprehensive study has been reported on all aspects of the transition of packed bed to the state of incipient fluidization (point of minimum fluidization, onset of fluidization): particle size and shape, size distribution in a batch of particles, fixed bed voidage, pressure drop through a packed bed and oneset of fluidization. A number of predictive equations have been compared that were proposed to estimate the minimum fluidization velocity. All the equations tested do not have any flow limitations and are applicable to laminar, transitional as well as to turbulent flow regime. While some equations have some foundation in theory, the other are more or less generalized correlations of experimental data amassed by different authors under various conditions. The influence of temperature and pressure on the minimum fluidization velocity has been explored with respect to the important applications such as combustion and gasification. Problems have also been discussed with transition from fixed to fluidized bed of binary and polydisperse systems.

An Experimental Investigation on Forced Convection Heat Transfer From a Cylinder Embedded in a Packed Bed

1994 ◽  
Vol 116 (1) ◽  
pp. 73-80 ◽  
Author(s):  
K. Nasr ◽  
S. Ramadhyani ◽  
R. Viskanta
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Forced Convection ◽  
Convection Heat Transfer ◽  
Particle Diameter ◽  
Packed Bed ◽  
Spherical Particles ◽  
Theoretical Equation ◽  
Convection Heat ◽  
Forced Convection Heat Transfer

Forced convection heat transfer from a cylinder embedded in a packed bed of spherical particles was studied experimentally. With air as the working fluid, the effects of particle diameter and particle thermal conductivity were examined for a wide range of thermal conductivities (from 200 W/m K for aluminum to 0.23 W/m K for nylon) and three nominal particle sizes (3 mm, 6 mm, and 13 mm). In the presence of particles, the measured convective heat transfer coefficient was up to seven times higher than that for a bare tube in crossflow. It was found that higher heat transfer coefficients were obtained with smaller particles and higher thermal conductivity packing materials. The experimental data were compared against the predictions of a theory based on Darcy’s law and the boundary layer approximations. While the theoretical equation was moderately successful at predicting the data, improved correlating equations were developed by modifying the form of the theoretical equation to account better for particle diameter and conductivity variations.

Hydrodynamic Models for Packed Beds with Low Tube-to-Particle Diameter Ratio

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Carlos O. Castillo-Araiza ◽  
Felipe Lopez-Isunza
Keyword(s):  
Experimental Data ◽  
Effective Viscosity ◽  
Particle Diameter ◽  
Packed Bed ◽  
Diameter Ratio ◽  
Packed Beds ◽  
Hydrodynamic Models ◽  
Viscous Term ◽  
Measured Velocity ◽  
Viscosity Parameter

In the last decade it has been a special interest to incorporate the hydrodynamics in packed bed reactor models. This seems to be important in the case of highly exothermic partial oxidation reactions normally performed in packed beds with low tube/particle diameter ratio (dt/dp< 5) because of the large void distributions in the radial and axial directions, which have a direct impact on the magnitude of radial, angular and axial profiles of the velocity field, and consequently on both, the temperature and concentration profiles in the catalytic reactor. A successful reactor model needs an adequate hydrodynamic description of the packed bed, and for this reason several models additionally incorporate empirical expressions to describe radial voidage profiles, and use viscous (Darcy) and inertial (Forchheimer) terms to account for gas-solid interactions, via Ergun's pressure drop equation. In several cases an effective viscosity parameter has also been used with the Brinkman's viscous term. The use of these various approaches introduce some uncertainty in the predicted results, as to which extent the use of a particular radial voidage expression, or the use of an effective viscosity parameter, yield reliable predictions of measured velocity profiles.In this work the predictions of radial velocity profiles in a packed bed with low tube to particle diameter ratio from six hydrodynamic models, derived from a general one, are compared. The calculations show that the use of an effective viscosity parameter to predict experimental data can be avoided, if the magnitude of the two parameters in Ergun's equation, related to viscous and inertial energy losses, are re-estimated from velocity measurements, for this particular packed bed. The predictions using both approaches adequately fit the experimental data, although the results are analyzed and discussed.

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