0
Scale formation represents a major operational problem encountered in thermal desalination plants. Scale may form because of the composition of the make-up, but mostly develops as a result of further change occurring during evaporation. Scale formation is mainly caused by crystallization of alkaline scales, e.g., CaCO3 and Mg(OH)2 and non-alkaline scale, e.g., CaSO4. The formation of CaCO3 scale strongly depends on temperature, pH, and the release rate of CO2 as well as on the concentrations of HCO3-, CO32-, Ca2+, and Mg2+ ions. Scaling in industrial processes is affected by the following factors: (i) bulk variables and composition, i.e. CaCO3 precipitation potential, pH buffering capacity, chloride and sulfate concentrations and concentration of dissolved oxygen, (ii) thermal effect, i.e. heat flux, surface temperature and bulk temperature, (iii) flow field, i.e. velocity of flow and solid/liquid interface conditions and (iv) substrate properties, i.e. materials properties and surface conditions.
In previous works, Al-Rawajfeh et al. [1-3] have modeled the CO2 release rates in multiple-effect distillers (MED)distillers. This model did not account for the deposition of alkaline scale and its effect on CO2 release rates. Calcium carbonate and magnesium hydroxide were assumed to precipitate at negligible rates. Recently, Al-Rawajfeh [4,5] developed a model to simulate the simultaneous release of CO2 with the deposition of CaCO3 and investigated their mutual release-deposition relationship in MED [4] and in the flash chambers in MSF distillers [5]. The influence of CO2 injection on the carbonate chemistry and the scale formation were also studied [6]. The model begin to calculate the CaCO3-Mg(OH)2 (alkaline) scale in the brine chambers, because part of the scale is deposited there and will be reduced from the total scale precipitate or reduce the ions available to precipitate CaSO4 scale inside the tubes when it is recycled with the make-up. Details on the CO2 release and alkaline scale modeling can be found in previous works [1-6].
REFERENCES
[1] Al-Rawajfeh, A. E., Glade, H., Ulrich, J., CO2 release in multiple-effect distillers Controlled by mass transfer with chemical reaction. Desalination, vol. 156, PP. 109-123, 2003.
[2] Al-Rawajfeh, A. E., Glade, H., Qiblawey, H. M., Ulrich, J., Simulation of CO2 release in multiple-effect distillers. Desalination, vol. 166, PP. 41-52, 2004.
[3] Al-Rawajfeh, A. E., Glade, H., Ulrich, J., Scaling in multiple-effect distillers: the role of CO2 release. Desalination, vol. 182, PP. 209-219, 2005.
[4] Al-Rawajfeh, A.E., Modelling of Alkaline Scale Formation in Falling-Film Horizontal-Tubes Multiple-Effect Distillers. Desalination, vol. 205, PP. 124-139, 2007.
[5] Al-Rawajfeh, A.E., Simultaneous desorption-crystallization of CO2- CaCO3 in multistage flash (MSF) distillers. Chem. Eng. Proc., Proc. Inten., vol. 47, PP. 2262-2269, 2008.
[6] Al-Rawajfeh, A.E., Al-Amaireh, M. N., The influence of CO2 injection on the carbonate chemistry and scaling in multiple-effect distillers. Desalination & Water Treat., vol. 7, PP. 191-197, 2009.
What else can I help you with?
What is the cost of setting up desalination plant?
Cost of course depends on capacity and desalination method. Shoaiba Desalination Plant, Saudi Arabia, uses MSF Flash technology with a total output capcity of 128 million gallons per day. Cost 1.6 billion $US.
What is the full form of MSF in power plant?
Multi-stage Flash (MSF) Desalination
How do you work ejector system of desalination plant?
to create vacuum for decreasing the boiling point. it works the base of converging-diverging procedure.
Where does the salt initially go in a desalination plant and how is it removed from the desalinator?
Salt water is pumped through a very fine membrane which does not allow the salt to pass through (osmosis). Only part of the water is "desalinated". The rest, with all the salt, is usually pumped back into the ocean, at some distance away from the plant.
How does a desalination plant operate?
A desalination plant operates by removing salt and other impurities from seawater or brackish water to produce fresh water suitable for human consumption, agriculture, or industrial use. The most common methods used in desalination plants are reverse osmosis (RO) and distillation. Here’s a brief overview of how each method works: Reverse Osmosis (RO) Intake: Seawater or brackish water is drawn from a source, usually through an intake pipe. Pre-treatment: The water passes through a series of filters to remove large particles, sediments, and other impurities that could clog or damage the RO membranes. High-Pressure Pump: The pre-treated water is then pressurized by high-pressure pumps to force it through semi-permeable RO membranes. Membrane Filtration: The RO membranes allow water molecules to pass through but block salt ions and other impurities. This results in two streams: freshwater (permeate) and concentrated brine (reject). Post-treatment: The permeate water is further treated to adjust pH levels, add necessary minerals, and ensure it meets quality standards for its intended use. Distribution: The treated fresh water is stored and distributed for use, while the brine is safely disposed of, usually back into the ocean after dilution to minimize environmental impact. Distillation Intake: Similar to RO, seawater is drawn into the plant through an intake system. Heating: The water is heated to produce steam. This can be done using various energy sources, including solar power, waste heat from power plants, or fossil fuels. Evaporation: The seawater is boiled in an evaporator, causing water to evaporate and leave behind salt and other impurities. Condensation: The steam is then condensed back into liquid form in a condenser. The condensed water is now desalinated. Post-treatment: As with RO, the distilled water may undergo post-treatment to ensure it meets quality standards. Distribution: The treated water is stored and distributed, while the remaining concentrated brine is disposed of. Key Components of a Desalination Plant Intake and Pre-treatment Systems: These systems prepare the raw water for the desalination process. Desalination Units: These include RO membranes or distillation chambers where the actual desalination occurs. Post-treatment Systems: These systems ensure the water is safe and suitable for its intended use. Energy Supply: Desalination is energy-intensive, so plants often have dedicated power supplies or utilize energy recovery systems to improve efficiency. Brine Disposal Systems: Proper disposal of the concentrated brine is crucial to minimize environmental impact. Environmental and Economic Considerations Energy Consumption: Desalination requires a significant amount of energy, which can impact its cost and environmental footprint. Brine Disposal: The disposal of brine must be managed to avoid harming marine ecosystems. Cost: Desalinated water is generally more expensive than other sources of freshwater due to the high energy and infrastructure costs. Despite these challenges, desalination is a crucial technology for providing fresh water in arid regions and areas with limited freshwater resources
Would you plant a desalination plant by the ocean or a pumping plant on a river and why?
a pumping plant because a desalination plant costs alot and they produce brine
Is living coral a tiny plant?
No, living coral is not a tiny plant. It is comprised of a group of animals inside of shells made of calcium carbonate.
Why is building a desalination plant costly?
It is due to the amount of energy needed to run a desalination plant, as well as the fines that have to be paid due to the amount of air pollution a desalination plant gives out.
What is chemical formula for soil calcium?
Calcium is a chemical element with the symbol Ca.
What is the name of calcium rich soil?
Calcium-rich soil is commonly referred to as calcareous soil. This type of soil contains high levels of calcium carbonate, which is beneficial for plant growth, especially for calcium-loving plants.
How do you make a model of a water desalination plant?
how to design a desalination plant of 2000 tonnes per day production of distillate ,the desalination type of evaporation multi stage ,,with material balance,?
Which substance is used in the neutralization of acidic soil?
Lime (calcium carbonate) is commonly used to neutralize acidic soil. Applying lime increases the soil pH, making the soil less acidic and more suitable for plant growth.
What is the chemical formula for Garden Lime?
Garden Lime, also known as Calcium Carbonate, is simply CaCO3.
When you add calcium carbonate to loam soil why does it stop the soil from becoming to acidic?
Calcium Carbonate decreases organic matter and grain yields so that although there is a lot of leaves about - the soil won't be too acidic. Calcium Carbonate may be particularly effective with soil under a tree.
How do you put desalination in a sentence?
The government of Saudi Arabia has just authorized the construction of a new seawater desalination plant.
Where are they turrenty building a desalintion plant in victorla?
what does they currently building a desalination plant in victoria
How is water separated from salt water in a desalination plant?
by ewangago kau
