Nobody downloaded yet

Water Desalination using Vacuum Membrane Distillation - Essay Example

Comments (0) Cite this document
Summary
The surfaces of the hydrophobic porous membrane are maintained at different temperatures, causing the vapor pressure difference. Conventional membrane distillation processes sometimes lead to extreme…
Download full paperFile format: .doc, available for editing
GRAB THE BEST PAPER98.7% of users find it useful
Water Desalination using Vacuum Membrane Distillation
Read TextPreview

Extract of sample "Water Desalination using Vacuum Membrane Distillation"

Download file to see previous pages Of course, it can also be used for water desalination [5].
Vapor migrates from the membrane surface to the permeate side. How this process occurs varies with the different configurations, depending on the feed solution which is treated [3, 11, 16]. All the configurations have advantages and disadvantages, depending on their applications. In Direct Contact Membrane Distillation, for instance, the membrane is in direct contact with the water only during liquid phases.
According to classical heat transfer theory, a thermal boundary is formed when liquid is in direct contact with a solid surface when their temperatures differ. This thermal boundary stays next to the solid surface, where the liquid exhibits its temperature fluctuations. The process of heat and mass transfer illustrates the membrane distillation process, wherein a microporous membrane separates two fluids of differing temperatures (membrane thickness of). The feed temperature decreases from at its bulk to at the membrane’s surface. Accordingly, the permeate temperature increases from at its bulk to at the membrane’s surface. Two thermal boundary layers appear at the feed side (with the thickness of) and the permeate side (with the thickness of) of the membrane respectively, as shown in Fig. 3.
where is the mass transfer flux through the membrane and is the latent heat of the volatile component. Here, is only a small part of the energy transferred through the membrane in the form of latent heat. The temperature difference between the two sides of the membrane also conducts heat through the membrane and the gas that fills the pores with flux, written as
The equation illustrates the temperature difference between the two sides of the hydrophobic membrane. Accounting for the vapor pressure difference is illustrated by, which is the driving force for mass transfer through the membrane. Three mechanisms regulate the mass transfer through the membrane:
The mass transfer mechanism ...Download file to see next pagesRead More
Cite this document
  • APA
  • MLA
  • CHICAGO
(“Water Desalination using Vacuum Membrane Distillation Essay”, n.d.)
Water Desalination using Vacuum Membrane Distillation Essay. Retrieved from https://studentshare.org/miscellaneous/1556889-water-desalination-using-vacuum-membrane-distillation
(Water Desalination Using Vacuum Membrane Distillation Essay)
Water Desalination Using Vacuum Membrane Distillation Essay. https://studentshare.org/miscellaneous/1556889-water-desalination-using-vacuum-membrane-distillation.
“Water Desalination Using Vacuum Membrane Distillation Essay”, n.d. https://studentshare.org/miscellaneous/1556889-water-desalination-using-vacuum-membrane-distillation.
  • Cited: 0 times
Comments (0)
Click to create a comment or rate a document

CHECK THESE SAMPLES OF Water Desalination using Vacuum Membrane Distillation

Wind power for water desalination including a comparison with solar power desalination

...desalination and energy cost per cubic meter the fresh water produced. The major aim is to determine the feasibility of the wind desalination in Greece and determine. Desalination Desalination can be categorized in thermal desalination, solar desalination and non-thermal desalination. Thermal desalination involves the processes of evaporation, crystallization and membrane distillation. Evaporation involves the processes of Multi-stage Flash evaporation, Multi-effect evaporation and vapour compression evaporation. However, the crystallization thermal...
57 Pages(14250 words)Dissertation

Basics of Molecular Beam Epitaxy

...thin film technologies like liquid phase epitaxy, chemical vapor phase deposition, sputtering, vacuum deposition etc. were developed and used to meet the stringent demands on these semiconductor devices. However, the semiconductor films produced by these processes were not structurally equivalent t the bulk material and hence were not of device grade. The problem associated with vapor phase deposition processes was differential vapor pressure of different constituents. For example vapor pressure of Ga and As differs by as much as two orders of magnitude at temperatures useful for thin film deposition. Therefore, to achieve equal vapor pressure and hence equal flux of arrival of Ga and As...
10 Pages(2500 words)Assignment

Simple Process for Water Distillation

..., the kind of water that fits human consumption has increasingly been scrutinized due to the level of impurities that were found to exist. In this regard, the current essay aims to explain the method for water distillation by converting impure water into chemically pure water through a simple and straightforward process. Water Distillation Process 1. Required Materials In every procedure, the people tasked to follow and adhere to the process should initially be oriented on the required materials or ingredients to be used. A quick search from the Science Fair Adventure website revealed that the basic...
3 Pages(750 words)Essay

Statistics Case Study - Desalination

...as shown below:       Debt/Equity $/kWH kWH/m3 US ?/m3 Plant Operating Costs: Power @/kWH $ 0.05 2.80 14.00 Membranes 4.10 Parts Replacement 6.90 Chemical Consumable 4.60 Op Margin 8.50 Labor, G&A 4.80 Office, Local 1.40 Capital Costs: Debt service 20 yr loan 75% 7% 19.44 Capital Recovery 25% 15%   13.89         33.33   Total US ?/m3         77.63 Generally the costs are derived from prevailing market rates in relation to the materials as well as costing rates prevailing. It is important to emphasize that while currently desalination has been treated with caution due to cost factors, as technology rises and more and more ways of lowering its associated costs are...
4 Pages(1000 words)Case Study

Distillation- Gas Chromatography Investigations

...Introduction Distillation is the technique often used in separating liquid mixtures. At a certain temperature, a pure liquid is known to have a specific vapor pressure (Harwood and Moody 145). Thus, heating the liquid often provides extra energy to the molecules. This energy is utilized by the molecules to change phase, that is, from the liquid phase into the gas phase. The temperature at which the liquid changes into vapor, in which case, the vapor pressure of a liquid at this temperature equals to the atmospheric pressure, and it is referred to as the boiling point. In the case where there are two compounds with a vast different vapor and pressures, then the two compounds can be separating through the...
4 Pages(1000 words)Lab Report

Membrane

...?Studying the impact of solute concentration on the rate of osmosis Introduction: Osmosis is defined as the movement of water molecules through a selective membrane (Freeman, 2010). Osmosis occurs so as to balance the water potential on either side of the membrane. Water potential is used to describe the tendency with which water moves from one region to another. This experiment was carried out in order to determine how the rate of osmosis changes under different solute concentrations. Solute concentrations heavily influence how osmosis occurs. In animal cells, when the solute concentration is equal on both sides of the...
4 Pages(1000 words)Lab Report

Suckwell Vacuum Cleaners, Ltd

...of inspection but to use information from inspections to do more than just move the defective product into the scrap or rework pile. Useful information from inspection can improve the process and the way the company do things in order to build quality in the assembly line. On the other hand, statistical quality control is an inspection method that is employed when large quantities of identical components or products pass through the line. Statistical control employs the use of run charts with limits that measures with precision the quality of the whole lot by inspecting a few representative samples. (Waters, 2002) Involving the Supplier Total quality management does...
9 Pages(2250 words)Case Study

Desalination Processes

...Membrane Distillation is a recent and unique separation technology, in use in the process industry. The process of separation in MD involvesthe concurrent transfer of heat and mass through a hydrophobic semi permeable membrane, using thermal energy. Consequently a separation of the feed solution into two components- the permeate or product and the retentate or the return stream occurs. MD utilizes low grade or alternative means e.g. solar energy, geothermal energy etc, as a source of thermal energy; and therefore also promises to be cost effective separation technology. Hence the process has come to acquire the attention and interest of researchers,...
19 Pages(4750 words)Essay

Batch Distillation Column

...MCCABE-THIELE ANALYSIS OF BATCH DISTILLATION Results and Inferences The following results were obtained during the batch distillation experiment: Thermocouple After 15 minutes After 30 minutes Steady State T1 77 78 70 T2 64 63 64 T3 63 63 63 T4 63 63 63 Take-off sample: 66 Bottom Sample: 97 After 15 minutes After 30 minutes Steady State Top 1.33089 1.32980 1.32937 Bottom 1.33445 1.33448 1.33447 From the Composition-Refractive Index graph that has been provided, the above data on refractive index at different times becomes useful. The refractive index for the sample is indicative of the composition of the mixture at the particular instance. In particular, the mole fraction of methanol in...
2 Pages(500 words)Assignment

Distillation column

...affected by peculiarities such as coking as well as the presence of suspended particles and therefore taking into account such considerations in the design will help minimize operational and maintenance costs. Commissioning the plant operations During the commissioning of the Distillation plant operations, a series of checks as well as counterchecks should be performed to ensure that the entire chemical plant does not have any design errors and is suitable for the distillation operations. During this stage, various systems and equipment such as the valves, coolant and the control loops of the distillation column are first made operational using safe liquids such as...
4 Pages(1000 words)Assignment
sponsored ads
We use cookies to create the best experience for you. Keep on browsing if you are OK with that, or find out how to manage cookies.

Let us find you another Essay on topic Water Desalination using Vacuum Membrane Distillation for FREE!

Contact Us