Exergy Analysis-Potential of Salinity Gradient Energy Source

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Arash Emdadi ◽  
Mansour Zenouzi ◽  
Amir Lak ◽  
Behzad Panahirad ◽  
Yunus Emami ◽  
...  
Keyword(s):  
Sodium Chloride ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Exergy Analysis ◽  
Salinity Gradient ◽  
Electrical Energy ◽  
Dead State ◽  
Gradient Energy ◽  
Reference Environment ◽  
Faster Development

Mixing of fresh (river) water and salty water (seawater or saline brine) in a controlled environment produces an electrical energy known as salinity gradient energy (SGE). Two main conversion technologies of SGE are membrane-based processes: pressure retarded osmosis (PRO) and reverse electrodialysis (RED). Exergy calculations for a representative river-lake system are investigated using available data in the literature between 2000 and 2008 as a case study. An exergy analysis of an SGE system of sea-river is applied to calculate the maximum potential power for electricity generation. Seawater is taken as reference environment (global dead state) for calculating the exergy of fresh water since the sea is the final reservoir. Aqueous sodium chloride solution model is used to calculate the thermodynamic properties of seawater. This model does not consider seawater as an ideal solution and provides accurate thermodynamics properties of sodium chloride solution. The chemical exergy analysis considers sodium chloride (NaCl) as main salt in the water of this highly saline Lake with concentration of more than 200 g/L. The potential power of this system is between 150 and 329 MW depending on discharge of river and salinity gradient between the Lake and the River based on the exergy results. This result indicates a high potential for constructing power plant for SGE conversion. Semipermeable membranes with lifetime greater than 10 years and power density higher than 5 W/m2 would lead to faster development of this conversion technology.

Determining the Potential of Salinity Gradient Energy Source Using an Exergy Analysis

2016 ◽  
Author(s):  
Arash Emdadi ◽  
Mansour Zenouzi ◽  
Gregory J. Kowalski
Keyword(s):  
Sodium Chloride ◽  
Power Density ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Exergy Analysis ◽  
Salinity Gradient ◽  
Chloride Concentration ◽  
Semipermeable Membranes ◽  
Dead State ◽  
Gradient Energy

Mixing of fresh (river) water and salty water (seawater or saline brine) in a control fashion would produces an electrical energy known as salinity gradient energy (SGE). Two main conversion technologies of SGE are membrane-based processes; pressure retarded osmosis (PRO) and reverse electrodialysis (RED). In PRO, semipermeable membranes placed between the two streams of solutions allow the transport of water from low-pressure diluted solution to high-pressure concentrated solution. RED requires two alternating semipermeable membranes that allow the diffusion of the ions but not the flow of H2O. Lifetime and power density of the semipermeable membrane are two main factors affecting on deployment of PRO and RED. Semipermeable membranes with lifetime greater than 10 years and power density higher than 5 W/m2 would lead to faster development of this conversion technology. An exergy analysis of an SGE system of sea-river can be applied to calculate the maximum potential power for electricity generation. Seawater is taken as reference environment (global dead state) for calculating the exergy of water since the seawater is the final reservoir. Once the fresh water is mixed with water of the sea or lake it becomes unuseful for human, agricultural or industrial uses loses all its exergy. Aqueous sodium chloride solution model is used in this study to calculate the thermodynamic properties of seawater. This model does not consider seawater as an ideal model and provides accurate thermodynamics properties of sodium chloride solution. As a case study, exergy calculation of Iran’s Urmia Lake-GadarChay River system. The chemical exergy analysis considers sodium chloride (NaCl) as main salt in the water of Lake Urmia. The sodium chloride concentration is more than 200 g/L in recent years. Based on the exergy results the potential power of this system is 329 MW. This results indicates a high potential for constructing power plant for salinity gradient energy conversion.

scholarly journals The use of Robinia pseudoacacia L fruit extract as a green corrosion inhibitor in the protection of copper-based objects

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Vahid Pourzarghan ◽  
Bahman Fazeli-Nasab
Keyword(s):  
Sodium Chloride ◽  
Corrosion Inhibition ◽  
Aqueous Extract ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Control Sample ◽  
Fruit Extract ◽  
Bronze Alloy ◽  
Sem Images ◽  
Green Inhibitor

AbstractThe most important inhibitors used in bronze disease are BTA and AMT. While these inhibitors control corrosion, they are toxic and cancerous. In this study, the acacia fruit extract (200 ppm to 1800 ppm) was used to the prevention of corrosion inhibition of bronze alloy in corrosive sodium chloride solution 0.5 M, for 4 weeks consecutively. The Bronze alloy used in this research, was made based on the same percentage as the ancient alloys (Cu-10Sn). IE% was used to obtain the inhibitory efficiency percentage and Rp can be calculated from the resistance of polarization. SEM–EDX was used to evaluate the surfaces of alloy as well as inhibitory. The experiment was conducted in split plot design in time based on the RCD in four replications. ANOVA was performed and comparison of means square using Duncan's multiple range test at one percent probability level. The highest rate of corrosion inhibition (93.5%) was obtained at a concentration of 1800 ppm with an increase in the concentration of the extract, corrosion inhibition also increased, i.e., more bronze was prevented from burning. Also, the highest corrosion inhibitory activity of Acacia extract (79.66) was in the second week and with increasing duration, this effect has decreased. EDX analysis of the control sample matrix showed that the amount of chlorine was 8.47%wt, while in the presence of corrosive sodium chloride solution, after 4 weeks, the amount of chlorine detected was 3.20%wt. According to the morphology (needle and rhombus) of these corrosion products based on the SEM images, it can be said, they are the type of atacamite and paratacamite. They have caused bronze disease in historical bronze works. The green inhibitor of Acacia fruit aqueous extract can play an effective role in inhibiting corrosion of bronze, but at higher concentrations, it became fungal, which can reduce the role of Acacia fruit aqueous extract and even ineffective. To get better performance of green inhibitors, more tests need to be done to improve and optimize.

DETERMINATION OF TRACE AMOUNTS OF SILVER IN GALENA ORES

1960 ◽  
Vol 38 (9) ◽  
pp. 1488-1494 ◽  
Author(s):  
E. J. Bounsall ◽  
W. A. E. McBryde
Keyword(s):  
Aqueous Solution ◽  
Nitric Acid ◽  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Silver Content ◽  
Aqueous Sodium Chloride Solution ◽  
Aqueous Sodium

An analytical method is described for the determination of microgram amounts of silver in galena ores, based on the "reversion" of silver dithizonate. Silver is separated from relatively large amounts of lead by extraction as dithizonate into chloroform from an aqueous 1:99 nitric acid solution. Separation from mercury, which is also extracted under these conditions and would, if present, interfere in the analysis, is achieved by reverting the dithizonate solution with a 5% aqueous sodium chloride solution which is also 0.015 molar in hydrochloric acid. Following dilution of this aqueous solution and adjustment of pH, silver is again extracted into chloroform as the dithizonate, and determined absorptiometrically. Analyses of a number of galena ore samples showed a precision of within 3% for a silver content ranging from 0.03 to 0.4%.Some other methods for isolating silver from these samples, which were tried but found unsatisfactory, are discussed.

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