Loading...
Search for:
distillation
0.009 seconds
Total 163 records
Impact of Internally Heat-Integrated Distillation Column Configuration on Energy Saving
, M.Sc. Thesis Sharif University of Technology ; Pishvaie, Mahmoud Reza (Supervisor) ; Rashtchian, Davood (Supervisor)
Abstract
Distillation is the most widely-used but the most energy-consuming separation process in the chemical industry. The thermal energy added at the reboiler is used to evaporate a liquid mixture and is wasted when liquefying the vapor flow at the condenser to obtain a reflux liquid flow. However, the thermal energy recovered at the condenser cannot be used to heat other flows in the same distillation column since its temperature is lower than the other stages. To improve the low energy efficiency of distillation, various new ideas have been proposed in the literature. One of them is the internally heat-integrated distillation column (HIDiC). In a conventional distillation column, the temperature...
Application of ideal temperature gradient technology to optimize the chemical exchange and distillation process of boron isotopes separation by (CH3)2O-BF3 complex
, Article Chemical Engineering and Processing: Process Intensification ; Volume 76 , February , 2014 , Pages 26-32 ; ISSN: 02552701 ; Ahmadi, S. J ; Sharif University of Technology
Abstract
To exert the optimum effect, the chemical exchange process to boron isotope separation was investigated. In this enrichment method the distillation of dimethyl ether-boron trifluoride complex, which was one of the most efficient industrial methods for purification of isotope boron-10, was optimized. In chemical exchange process of boron isotopes separation two chemical reactions occur. The first one is the decomposition reaction that is an endothermic reaction. The second one is the exchange reaction that is a pyrogenic reaction. With increasing temperature, the decomposition reaction is speeded while the exchange reaction is slowed down. Affecting on both decomposition and exchange...
Desalination through sweeping gas membrane distillation alternative
, Article CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference PRES ; 2012 ; Kargari, A ; Shirazi, M. M. A ; Fatehi, L ; Soleimani, M ; Sharif University of Technology
2012
Abstract
Sweeping gas membrane distillation process was studied using flat sheet hydrophobic PTFE membrane. The effects of operating parameters, including feed temperature, feed flow rate, sweeping gas flow rate, and feed concentration on the permeate flux, were determined. The feed temperature significantly influenced the permeate flux. Increasing the feed temperature increased the permeate flux. The increase of feed concentration caused to reduce the permeate flux due to the increase of concentration polarization effect and reduction of vapor pressure difference. Sweeping gas flow rate led to increase the permeate flux due to reduction of vapor pressure in the permeate side. Higher air flow rate...
Conceptual design double feed reactive distillation columns
, Article CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference PRES ; 2012 ; Ceska Rafinerska; DEZA; Synpo; BorsodChem; Prazska Plynarenska a.s ; Sharif University of Technology
Abstract
An approach to assess feasibility and determine the feasible range of operating parameters for double-feed reactive distillation columns is put forward. It is based on the combination of analysis of the pinch point maps for the middle-section in compositional space and an efficient shortcut design method. The existence of the liming bounds on operating parameters is observed. The methodology is illustrated by the production of methyl acetate and ethyl acetate. The analysis provides an efficient method to identify the most promising candidates of double feed reactive distillation columns and to study the design flexibility in terms of operating parameters. This is an abstract of a paper...
Economic optimization of heat pump-assisted distillation columns inmethanol-water separation
, Article Energy ; Volume 80 , 2015 , Pages 496-508 ; 03605442 (ISSN) ; Jafari, M ; Kasiri, N ; Ivakpour, J ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
Finding efficient alternative to CDiC (Conventional Distillation Column) for methanol-water separation has been an attractive field of study in literature. In this work, five heat pump-assisted schemes are proposed and compared to each other to find the optimal one; (1) VRC (Vapor Recompression Column), (2) external HIDiC (Heat-Integrated Distillation Column), (3) intensified HIDiC with feed preheater, (4) double compressor intensified HIDiC-1, and (5) double compressor intensified HIDiC-2. GA (Genetic Algorithm) is then implemented for optimization of the schemes when TAC (Total Annual Cost) is its objective function. During optimization, two new variables are added for using only...
Vacuum enhanced membrane distillation for trace contaminant removal of heavy metals from water by electrospun PVDF/TiO2 hybrid membranes
, Article Korean Journal of Chemical Engineering ; Volume 33, Issue 7 , 2016 , Pages 2160-2168 ; 02561115 (ISSN) ; Monfared, S. M ; Amini, Y ; Dastbaz, A ; Sharif University of Technology
Springer New York LLC
Abstract
Electrospun hybrid membranes were synthesized using electrospinning of Poly (vinylidenefluoride) - titanium tetraisopropoxide (PVDF-TTIP) sol. Asymmetric post-treatment of membrane conducted for deprotonation of titanate and making hydrophilic/hydrophobic dual characteristics. The membranes were characterized by various methods such as wettability, scanning electron microscopy, infrared spectroscopy, X-ray diffraction and liquid entry pressure tests. For evaluating the separation performance, these membranes were applied in the VMD process to treat water heavy metal contaminants. The effects of operating parameters such as flow rate, temperature and membrane properties as porosity, on...
On-line nonlinear dynamic data reconciliation using Extended Kalman Filtering: Application to a distillation column and a CSTR
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 28, Issue 3 , 2009 , Pages 1-14 ; 10219986 (ISSN) ; Mehrabani Zeinabad, A ; Bozorgmehry Boozarjomehry,R ; Sharif University of Technology
Abstract
Extended Kalman Filtering (EKF) is a nonlinear dynamic data reconciliation (NDDR) method. One of its main advantages is its suitability for on-line applications. This paper presents an on-line NDDR method using EKF. It is implemented for two case studies, temperature measurements of a distillation column and concentration measurements of a CSTR. In each time step, random numbers with zero mean and specified variance were added to simulated results by a random number generator. The generated data are transferred on-line to a developed data reconciliation software. The software performs NDDR on received data using EKF method. Comparison of data reconciliation results with simulated...
Brine elimination by hybridization of a novel brine-recycle bubble-column humidification-dehumidification system with a multiple-effect distillation system
, Article Energy Conversion and Management ; Volume 217 , 2020 ; Moosavi, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Over the past decades, drastic growth in the installed capacity of seawater desalination systems has increased the energy consumption and brine discharge to the environment. However, using renewable energies and zero liquid discharge systems for minimizing these challenges is limited due to the higher fresh water cost of the systems rather than that of the conventional systems. In this research, a bubble-column humidification-dehumidification zero liquid discharge system is coupled with a multiple-effect distillation/vapor compression system in a novel way to overcome the high water cost of conventional zero liquid discharge systems. Further, the base system and the solar-powered system is...
Study on commercial membranes and sweeping gas membrane distillation for concentrating of glucose syrup
, Article Journal of Membrane Science and Research ; Volume 6, Issue 1 , 2020 , Pages 47-57 ; Kargari, A ; Bastani, D ; Soleimani, M ; Fatehi, L ; Sharif University of Technology
Amirkabir University of Technology - Membrane Processes Research Laboratory
2020
Abstract
In this work, sweeping gas membrane distillation (SGMD) process was used for concentrating of glucose syrup. The main questions in this work include: is SGMD process practical for concentrating of glucose solution prior the fermentation step in bioethanol process?. and are the commercially available hydrophobic membranes sufficient enough to develop the SGMD process in pilot scale for this issue?. To answer these questions, SGMD process was performed using three commercial membranes made of PP, PVDF and PTFE. All membranes characterized using scanning electron and atomic force microscopes for their morphological and topographical features. Important operating parameters including feed...
Simulation and control of an aromatic distillation column
, Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 26, Issue 2 , 2007 , Pages 97-108 ; 10219986 (ISSN) ; Shahrokhi, M ; Sharif University of Technology
2007
Abstract
In general, the objective of distillation control is to maintain the desired products quality. In this paper, the performances of different one point control strategies for an aromatic distillation column have been compared through dynamic simulation. These methods are: a) Composition control using measured composition directly. This method sufferes from large sampling delay of measuring devices, b) Composition control by controlling the temperature of a specific tray. In this strategy, the composition-temperature relationship is used to find the temperature setpoint corresponding to the desired composition. Since composition-temperature relation depends on feed condition, an artificial...
Optimization of energy consumption in the process of dehumidification of natural gas
, Article Biointerface Research in Applied Chemistry ; Volume 11, Issue 6 , 2021 , Pages 14634-14639 ; 20695837 (ISSN) ; Shiva, N ; Khajehpour, H ; Sharif University of Technology
AMG Transcend Association
2021
Abstract
In recent years, there has been a great tendency to optimize energy consumption in the oil and gas industry’s upstream and downstream equipment. One of the most energy-intensive processes in natural gas refineries is the condensate stabilization unit (gas condensate). The main bottlenecks of energy consumption in the old units are condensated stabilization (dehumidification with ethylene glycol), heater reboiler, and air coolers (air coolers). Therefore, much attention should be paid to these applications and electricity and steam consumption in this unit. In this study, a simulated model based on the Gachsaran gas refinery’s new layout has been developed. Optimization of this part of the...
Photothermally heated and mesh-gridded solar-driven direct contact membrane distillation for high saline water desalination
, Article International Journal of Heat and Mass Transfer ; Volume 199 , 2022 ; 00179310 (ISSN) ; Asadollahi, M ; Mousavi, S.A ; Rajabi ghahnavieh, A ; Behzadi Sarok, M ; Khayet, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Photothermally heated and mesh-gridded membrane distillation (PHMD) system is proposed for desalination of high saline aqueous solutions. A triple-layered membrane, composed of a photothermal top nanofibrous layer containing polyacrylonitrile and dispersed carbon black nanoparticles and a polyvinylidene fluoride porous membrane supported on a nonwoven polyester, was prepared. A polypropylene mesh was used to hold the membrane. A 3D numerical simulation of the PHMD system was carried out by COMSOL and the appropriate length of the membrane module was determined. The effects of various operating parameters including solar radiation intensity on the permeate flux and thermal efficiency were...
Effect of Operating Conditions and Additives on the Product Yield and Sulfur Content in Thermal Cracking of a Vacuum Residue from the Abadan Refinery
, Article Energy and Fuels ; Volume 29, Issue 8 , 2015 , Pages 5452-5457 ; 08870624 (ISSN) ; Ivakpour, J ; Khorasheh, F ; Sharif University of Technology
American Chemical Society
2015
Abstract
Thermal cracking of a vacuum distillation residue of the Abadan refinery in Iran was performed under delayed coking conditions to investigate the effect of operating conditions on the yield and sulfur content of products. At reaction temperatures of 440-500 °C and pressures of 1, 3, and 5 bar, the products included gases, liquids, and coke. The yields of liquid products were higher at 1 bar compared to those for higher pressures. Increasing the reaction temperature at a given reaction pressure led to an increase in the yield of liquid products. Increasing the reaction pressure at a given reaction temperature led to higher yields of coke and gases as well as a decrease in the sulfur content...
Simple and rapid determination of effective Murphree component efficiencies for operating absorbers, strippers and distillation columns filled with any type of trays
, Article Separation and Purification Technology ; Volume 139 , January , 2015 , Pages 104-108 ; 13835866 (ISSN) ; Sharif University of Technology
Elsevier
2015
Abstract
Estimating efficiency of an operating column has to be distinguished from that of a column being designed. This crucial point has been totally overlooked in the literature. All the methods and models available for predicting the Murphree efficiencies of tray columns have been developed for the design case. They generate their own mass and heat transfer rates and empirical parameters rather than produce true transfer rates by using operating column (realistic) data, especially the specifications of outlet streams. In addition, most of these methods are limited in application and insufficient in accuracy, especially if applied outside the range of conditions under which they were formulated....
Energy consumption in pervaporation, conventional and hybrid processes to separate toluene and i-octane
, Article Chemical Engineering and Processing - Process Intensification ; Volume 128 , June , 2018 , Pages 46-52 ; 02552701 (ISSN) ; Mohebbi, V ; Mosayyebi Behbahani, R ; Ramazani Saadat Abadi, A ; Sharif University of Technology
Elsevier B.V
2018
Abstract
Chemical industries need to employ new process designs due to environmental policies and energy optimization because of the global energy challenge. Pervaporation has been introduced as a promising alternative for conventional processes such as distillation, known as energy intensive process, in chemical plants. In this work, the energy consumption of different processes for separation of toluene and i-octane (representatives of aromatics and aliphatic mixtures) has been evaluated, based on our previous laboratory pervaporation experiments using Polyvinyl alcohol/Graphene oxide mixed matrix membranes. Accordingly, hybrid distillation-pervaporation and cascade pervaporation systems have been...
LPG mass separation by vortex tube cascade and its economics
, Article Applied Thermal Engineering ; Volume 148 , 2019 , Pages 1139-1147 ; 13594311 (ISSN) ; Alighardashi, H ; Farhadi, F ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
In the present experimental study, the effect of operating parameters such as inlet and outlet pressure as well as inlet temperature on the mass separation capability of vortex tubes (VTs) for a gas mixture is investigated. Specifically, concentrating heavier components of a gas mixture in the hot outlet stream is considered. Proposing a semi-empirical index from the experimental study, the simulation of different arrangements of VTs, and the effect of recycling a portion of the hot outlet stream on its mass separation performance are investigated. Moreover, the proposed separation method by VTs is economically compared with commonly used methods by distillation columns and two-phase...
Nanomaterial-assisted pyrolysis of used lubricating oil and fuel recovery
, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; 2020 ; Abdoli, M. A ; Khorasheh, F ; Nezhadbahadori, F ; Bayandori Moghaddam, A ; Sharif University of Technology
Taylor and Francis Inc
2020
Abstract
Used lubricating oil (ULO) is a heavy mixture of various hydrocarbons and needs to be treated before discharging. Considering ULO nature, it is more favorable to recover lighter hydrocarbon cuts from ULO, which not only improves the whole process economically, but also prevents the emission of hardly decomposable hydrocarbons into the environment. In this research, the potential of pyrolysis method for ULO recovery was studied. Furthermore, graphene nanoplatelets (GNP), γ- Fe2O3 and ZnO nanoparticles were used to improve the kinetics of the process and their impacts on the final product quality were evaluated. Based on the results, adding nanomaterials increased the tendency to produce gas...
Class attention map distillation for efficient semantic segmentation
, Article 1st International Conference on Machine Vision and Image Processing, MVIP 2020, 19 February 2020 through 20 February 2020 ; Volume 2020-February , 2020 ; Kasaei, S ; Sharif University of Technology
IEEE Computer Society
2020
Abstract
In this paper, a novel method for capturing the information of a powerful and trained deep convolutional neural network and distilling it into a training smaller network is proposed. This is the first time that a saliency map method is employed to extract useful knowledge from a convolutional neural network for distillation. This method, despite of many others which work on final layers, can successfully extract suitable information for distillation from intermediate layers of a network by making class specific attention maps and then forcing the student network to mimic producing those attentions. This novel knowledge distillation training is implemented using state-of-the-art DeepLab and...
Step-by-step improvement of mixed-matrix nanofiber membrane with functionalized graphene oxide for desalination via air-gap membrane distillation
, Article Separation and Purification Technology ; Volume 256 , 2021 ; 13835866 (ISSN) ; Karimi Sabet, J ; Abbasi, F ; Moosavian, M. A ; Sharif University of Technology
Elsevier B.V
2021
Abstract
A straightforward three-stage method was applied to fabricate a super-hydrophobic mixed-matrix nanofiber membrane using the electrospinning method for desalination purpose. First, a hydrothermal technique was applied to synthesize a super-hydrophobic nano-sheet, called octadecylamine-reduced graphene oxide (ODA-rGO) with a water contact angle of 162°, which was then added to PVDF-HFP dope solution. After, 0.005 wt% LiCl was added to the dope solution to decrease the mean pore size by increasing solution conductivity. Moreover, some membranes were hot-pressed to improve liquid entry pressure (LEP). Eventually, a top-quality nanofiber membrane was synthesized using 0.1 wt% ODA-rGO and 0.005...
Separation of Boron Isotopes by Distillation of (CH3)2O-BF3 Complex
, M.Sc. Thesis Sharif University of Technology ; Outokesh, Mohammad (Supervisor) ; Ahmadi, Javad (Supervisor)
Abstract
Natural boron includes two stable isotopes 10B and 11B with 19.3 and 80.7 weight percent respectivley.10B isotope has a high thermal neutron absorption cross section. So isotope 10B material is suitable for making atomic reactor control rods. Other and even more important applications of 10B are in disclosing neutrons in order to measure neutron reactors fluxes and also are in nuclear physics laboratories and medical radiation. This isotope also is used in the pharmaceutical and the military industries. There are several methods for separating boron isotopes. Among the distillation methods, thermal diffusion of BF3, distillation of BF3, distillation of methyl borate, boric acid distillation...