scholarly journals Integration of Process Modeling, Design, and Optimization with an Experimental Study of a Solar-Driven Humidification and Dehumidification Desalination System

Processes ◽  
2018 ◽  
Vol 6 (9) ◽  
pp. 163 ◽  
Author(s):  
Mohammed Alghamdi ◽  
Faissal Abdel-Hady ◽  
A. Mazher ◽  
Abdulrahim Alzahrani
Keyword(s):  
Closed Loop ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Circulation Rate ◽  
Feed Water ◽  
Parabolic Trough ◽  
Circulating Water ◽  
Electrical Generation ◽  
The Impact ◽  
Promising Source

Solar energy is becoming a promising source of heat and power for electrical generation and desalination plants. In this work, an integrated study of modeling, optimization, and experimental work is undertaken for a parabolic trough concentrator combined with a humidification and dehumidification desalination unit. The objective is to study the design performance and economic feasibility of a solar-driven desalination system. The design involves the circulation of a closed loop of synthetic blend motor oil in the concentrators and the desalination unit heat input section. The air circulation in the humidification and dehumidification unit operates in a closed loop, where the circulating water runs during the daytime and requires only makeup feed water to maintain the humidifier water level. Energy losses are reduced by minimizing the waste of treated streams. The process is environmentally friendly, since no significant chemical treatment is required. Design, construction, and operation are performed, and the system is analyzed at different circulating oil and air flow rates to obtain the optimum operating conditions. A case study in Saudi Arabia is carried out. The study reveals unit capability of producing 24.31 kg/day at a circulating air rate of 0.0631 kg/s and oil circulation rate of 0.0983 kg/s. The tradeoff between productivity, gain output ratio, and production cost revealed a unit cost of 12.54 US$/m3. The impact of the circulating water temperature has been tracked and shown to positively influence the process productivity. At a high productivity rate, the humidifier efficiency was found to be 69.1%, and the thermal efficiency was determined to be 82.94%. The efficiency of the parabolic trough collectors improved with the closed loop oil circulation, and the highest performance was achieved from noon until 14:00 p.m.

Springs® Design Optimized By Seawater Quality. Laboratory Pilot Tests

2021 ◽  
Author(s):  
Pierre Pedenaud ◽  
Marianna Rondon ◽  
Nicolas Lesage ◽  
Eric Tournis ◽  
Riccardo Giolo ◽  
...  
Keyword(s):  
Water Quality ◽  
Operating Conditions ◽  
Single Stage ◽  
Plant Performance ◽  
Future Application ◽  
Feed Water ◽  
Nanofiltration Membranes ◽  
Two Stage ◽  
Seawater Quality ◽  
The Impact

Abstract A new seawater laboratory pilot has been installed in order to evaluate the impact of the seawater quality on the performance of nanofiltration membranes and filters. The test program implemented was designed to produce the data required to optimize the design and operating parameters of a subsea sulfate removal plant, particularly with respect to the technology developed by Total, Saipem and Veolia, co-owners of the development. The equipment qualification plan is approaching completion with the development of subsea barrier-fluidless pumps, all-electric control systems, high-cycling valves operated by electric actuators and subsea water analyzers. This presented pilot laboratory study completes this plan. Nanofiltration membranes are commonly used to remove the sulfates found in seawater before the water is injected into wells. The principal advantages of relocating this equipment from topside to subsea are better reservoir sweep control, a substantial subsea water injection network reduction and savings on space and weight on the topsides deck. The move to subsea offers the opportunity to simplify the process due to improved deep water quality. This was previously demonstrated through a subsea test campaign. This new pilot study provides data both on the performance of a plant operating with different feed water quality and on the success of operating changes to further optimize the plant performance. The pilot has been installed at the Palavas-les-Flots site in France. Raw water collected from the basin was mixed with ultra-filtered water in order to calibrate the feed water quality. The pilot includes a two stage nanofiltration configuration and single stage nanofiltration unit. The two stage configuration was used to produce data for operation across an array of feed water quality and plant operating conditions. The single stage unit was used to produce data on membrane fouling over a long operating duration. Results from these tests and discussion on how this data relates to subsea plant performance shall be presented. This innovative approach enables a wide range of subsea water quality to be simulated and tested against different process configurations of the subsea unit. Indeed, for each industrial subsea application, the raw seawater quality is dependent on both the region and the depth of the seawater inlet. With this experimental data acquisition campaign and understanding of the seawater quality at inlet, the system design can be tailor-made for each future application case.

Arsenic mass balance in a paper mill and impact of the arsenic release from the WWTP effluent on the Moselle River

2011 ◽  
Vol 63 (7) ◽  
pp. 1349-1356 ◽  
Author(s):  
C. Michon ◽  
M.-N. Pons ◽  
P. Bauda ◽  
H. Poirot ◽  
O. Potier
Keyword(s):  
Arsenic Concentration ◽  
Treatment Plant ◽  
Paper Mill ◽  
Operating Conditions ◽  
Anthropogenic Source ◽  
Feed Water ◽  
Water Production ◽  
Gravel Pit ◽  
Wwtp Effluent ◽  
The Impact

Rivers used for drinking water production might be subject to anthropogenic pollution discharge upstream of the intake point. This problem was investigated in the case of the Moselle River, used for water production in Nancy (350,000 inhabitants) and which might be impacted by industrial activities 60 km upstream. The arsenic flux of a pulp and paper mill discharging in the Moselle River at this location has been more specifically investigated. The main sources of arsenic in that mill seemed to be the recovered papers and the gravel pit water used as feed water. The arsenic input related to wood and bark was limited. The main arsenic outputs from the plant were the paper produced on site and the deinking sludge. The arsenic concentration in the effluent of the wastewater treatment plant (WWTP) was not correlated to the one in the gravel pit water, but may depend on the operating conditions of the WWTP or the changes in processes of the mill. The impact of this anthropogenic source of arsenic on the Moselle River was slightly larger in summer, when the flowrate was lower. Globally the impact of the paper mill on the Moselle River water quality was limited in terms of arsenic.

scholarly journals Arsenic removal by the micellar-enhanced ultrafiltration using response surface methodology

2019 ◽  
Vol 20 (2) ◽  
pp. 574-585 ◽  
Author(s):  
Oznur Begum Gokcek ◽  
Nigmet Uzal
Keyword(s):  
Response Surface Methodology ◽  
Aqueous Solutions ◽  
Response Surface ◽  
Removal Efficiency ◽  
Surfactant Concentration ◽  
Arsenic Removal ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Micellar Enhanced Ultrafiltration ◽  
The Impact

Abstract The present research investigates the removal of arsenic (As) from aqueous solutions using micellar-enhanced ultrafiltration (MEUF) by utilizing two different surfactants: benzethonium chloride and dodecyl pyridinium chloride (BCl and DPCl). The impact of the operating variables and maximum removal efficiency were found under different conditions for BCl and DPCl surfactants. The maximum As rejection efficiency for MEUF with BCl and DPCl surfactants is 92.8% and 84.1%, respectively. In addition to this, a statistics-based experimental design with response surface methodology was used for the purpose of examining the impact of operating conditions, including initial pH, initial As concentration (ppb), and surfactant concentration (BCl, mM) in As-removal from aqueous solutions. In the analysis of the experimental data, a second-order polynomial model that was validated by statistical analysis for the BCl surfactant was used. On the basis of the response model created, the removal of As ions was acquired at optimum operating parameters, including the initial As concentration of 150 ppb, surfactant concentration of 5 mM and pH 10 for the BCl surfactant with 92.8% As-removal efficiency.

scholarly journals Study of the impact of NPP rated thermal power uprate on process behavior at different transient conditions

2018 ◽  
pp. 9-13 ◽  
Author(s):  
A. G. Nikulenkov ◽  
D. V. Samoilenko ◽  
T. V. Nikulenkova
Keyword(s):  
Power Unit ◽  
Thermal Power ◽  
Operating Conditions ◽  
Life Assessment ◽  
Feed Water ◽  
Dimensional System ◽  
Residual Service Life ◽  
Safety Level ◽  
Coolant Pump ◽  
The Impact

Today, objective preconditions have been formed to find the ways on how to increase cost-effectiveness of NPPs operation, while providing the required safety level. One of such ways to increase thermal nominal power of power unit. The paper provides for the results of reactor behavior analysis at increased thermal power above nominal received using a one-dimensional system computer code RELAP5/MOD3.2 and relevant model of VVER-1000 (V-320) power unit. Calculation analyses are performed for quasi-static reactor operating conditions and transients using realistic approach in terms of initial performance parameters of reactor installation. In researches, representative initial events for transients have been selected according to the principle described further. For an abnormal operation, an event has been selected based on its high frequency and consequences, which require decreasing reactor power down to 50 % of nominal thermal power. For emergency conditions an event has been selected which is caused by external extreme impacts typical for Ukrainian NPP sites resulting in the worst consequences. Thus, the transients are represented by events associated with failure of a single turbine-driven feed water pump and total station blackout unit. To analyze emergency conditions caused by long-term blackout, they were additionally accompanied by a leakage through reactor coolant pump seals. Given that increase of steam flow in a turbine at increased thermal power above nominal requires additional studies on residual service life assessment of its critical components, a 3-D model of high-pressure rotor of a full speed turbine is proposed for further studies. Based on the calculations a comparative analysis of major parameters of the reactor at rated and increased thermal power is performed with assessment of significant factors to be considered in further studies on increase of installed thermal output of NPP unit.

Parameterization of a Piezoelectric Nanomanipulation Device

2006 ◽  
Author(s):  
Ravi Patel ◽  
Benjamin Legum ◽  
Yury Gogotsi ◽  
Bradley Layton
Keyword(s):  
Closed Loop ◽  
Open Loop ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Actuation Time ◽  
Normalized Error ◽  
Pick And Place ◽  
Fine Mode ◽  
Task Oriented ◽  
Speed And Accuracy

Through measurement of hysteresis and drift in a piezoelectrically driven multi-axis multi-positioner nanomanipulator, we have quantified error over ranges of three primary operating parameters: gain, duty cycle, and actuation time. A total of sixty-nine curves were plotted, and error and drift measured in a single operating plane. All data shown were collected on the Zyvex L-100 nanomanipulator operating in an open-loop programmed method, in both coarse (12mm range, 2–5 μm precision) and fine mode (100 μm range, 10–50 nm precision). In general, the normalized error was reduced at larger actuation distances and in coarse mode. These results may be used to define optimum operating conditions for piezoelectrically actuated nanomanipulators and micromanipulators whereby the goal is to find a balance between speed and accuracy. The results also are intended to allow for optimal control in closed-loop operation and for task-oriented and pick-and-place operations.

scholarly journals Removal of 4-Nitrophenol from Aqueous Solution by Using Polyphenylsulfone-Based Blend Membranes: Characterization and Performance

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 171
Author(s):  
Ali Amer Yahya ◽  
Khalid T. Rashid ◽  
Maryam Y. Ghadhban ◽  
Noor Edin Mousa ◽  
Hasan Shaker Majdi ◽  
...  
Keyword(s):  
Pore Size ◽  
Cross Section ◽  
Feed Solution ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Operational Variables ◽  
Blend Membranes ◽  
Dope Solution ◽  
And Performance ◽  
The Impact

Among many contaminants in wastewater, organic phenol compounds presented a major concern to endanger the water resources safety. In the present study, blend nanofiltration (NF) membranes comprising polyphenylsulfone (PPSU) and polyethersulfone (PES) were prepared via the non-induced phase separation and their performance was examined against 4-Nitrophenol (4-NP). The PES ratio in the dope solution was varied from 6 to 9 wt.% to probe the impact of PES on the retention and permeation characteristics of the final membranes. A series of experimental tools were employed to estimate the characteristics of the membranes, including surface and cross-section, hydrophilicity, pore size and pore size distribution. Performance evaluation of the NF membranes was conducted considering two operational variables; pH and initial feed solution. About 99% removal of 4-NP along with 6.2 L/m2.h.bar was achieved at the optimum operating conditions as revealed by optimization and mathematical modelling.

Steady and Pulsed Flow Performance Trends of Higher Concentration DMFCs

2006 ◽  
Author(s):  
Larry McCarthy ◽  
Comas Haynes
Keyword(s):  
Energy Density ◽  
Direct Methanol Fuel Cells ◽  
High Energy ◽  
Operating Conditions ◽  
High Energy Density ◽  
Methanol Crossover ◽  
Fuel Delivery ◽  
Fuel Mixtures ◽  
The Impact ◽  
Promising Source

Direct methanol fuel cells (DMFCs) are a promising source of energy due to their potentially high energy density, facilitated fuel delivery and storage, and precluded fuel processing. However, DMFCs have several challenges which need to be resolved before they can replace existing energy sources. Some of these challenges include lower power density, relatively high cost, and uncertain reliability. These issues are all promoted, at least in part, by the methanol crossover phenomenon, wherein membrane permeability allows the undesirable species transport of methanol from the anode to the cathode. This phenomenon also causes the requirement of dilute fuel mixtures, which is undesirable from an energy density viewpoint. Prior research has shown that methanol crossover can be reduced by operating DMFCs in a transient mode [1,2]. Thus, a study has been performed to investigate the impact of hydraulic pulsing (HP) at different operating conditions, such as fuel concentration, current density, and number-of-stoichs (NOS). Furthermore, the cell’s performance is being characterized at different steady flow concentrations to highlight the impact of fuel dilution.

Understanding how operating conditions affect biofouling structure in spacer filled membrane filtration channels using optical coherence tomography

2020 ◽  
Author(s):  
Kees Theo Huisman ◽  
Bastiaan Blankert ◽  
Szilard Bucs ◽  
Johannes S. Vrouwenvelder
Keyword(s):  
Optical Coherence Tomography ◽  
Reverse Osmosis ◽  
System Performance ◽  
Operating Conditions ◽  
Process Conditions ◽  
Feed Water ◽  
Optical Coherence ◽  
Biofilm Development ◽  
Biofilm Structure ◽  
The Impact

<p><strong>Abstract</strong></p> <p>The growth of biofilms, causing biofouling on the membrane and feed spacer surface, is an unavoidable phenomenon in reverse osmosis. Biofouling can lead to unacceptable losses in product quality and quantity, and membrane lifetime. Process conditions such as crossflow velocity and nutrient concentration in the feed water strongly affect the development of biofilms. To improve system performance, understanding the relation between process conditions, biofilm development, and system performance is key. Optical coherence tomography (OCT), is increasingly applied to characterize biofilm structure in-situ and non-destructively. In OCT, near-infrared light is used to capture 2D and 3D images from within optical scattering media. In spacer filled channels with representative biodegradable nutrient conditions in the feed, biofilms often develop heterogeneously and dispersed. In such systems, commonly used structural parameters such as average thickness, average roughness, and average porosity may not be reflected in the system performance.</p> <p>In this study, biofilm structural and spatial parameters are explored with the objective to link biofouling in spacer filled channels to system performance indicators. For this purpose, biofilms are grown in membrane fouling simulators at different nutrient concentrations and flow rates. Biofilm development on the feed spacer and on the membrane and system performance (pressure drop, transmembrane pressure, rejection) are monitored. Understanding the impact of (i) feed water quality and flow rate on biofilm growth and of (ii) biofilm structure and spatial distribution on system performance will lead to the development of more effective strategies for biofouling control.</p> <p><strong>Keywords</strong></p> <p>Biofouling; desalination; drinking water production; reverse osmosis; optical coherence tomography; feed spacer; biofilm structure</p>

Transient Characteristics of a Closed-Loop Pipe System During Pump Stopping Periods

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Dazhuan Wu ◽  
Peng Wu ◽  
Shuai Yang ◽  
Leqin Wang
Keyword(s):  
Kinetic Energy ◽  
Flow Rate ◽  
Rotational Speed ◽  
Closed Loop ◽  
Transient Flow ◽  
Operating Conditions ◽  
Rotational Inertia ◽  
Transient Characteristics ◽  
Pipe System ◽  
The Impact

In order to study the transient characteristics of a closed-loop pipe system with room temperature water, experiments were carried out based on different pump stopping periods from rate rotational speed to zero. Various stopping periods were realized by changing the rotational inertia of the rotors, controlling the frequency of the motor and braking the shaft. Experimental results of different operating schemes were compared, and transient flow rate of the pipe system and transient characteristics of the pump were analyzed. The influences of the kinetic energy of the loop fluid and pump rotors to the stopping periods were summarized. Results show that rapid change of the pump operating conditions occurs during the stopping period and transient flow rate of the pipe system and characteristics of the pump depend largely on the way of stopping. The kinetic energy stored in the pump can drive the impeller keeping rotating for more time after the motor is shutdown. Due to the kinetic energy stored in the loop pipe, the flow rate does not reach zero immediately after the rotational speed reaches zero. The inertia of pump rotor and fluid inertia affect the impact of fluid flow and the duration of the loop during pump stopping period.

Grid-Zone Particle Hydrodynamics and Solid Circulation in a Multiple Jet Fluidized Bed

2012 ◽  
Author(s):  
Gaurav Agarwal ◽  
Brian Lattimer ◽  
Srinath Ekkad ◽  
Uri Vandsburger
Keyword(s):  
Fluidized Bed ◽  
Sudden Change ◽  
Particle Diameter ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Orifice Diameter ◽  
Circulation Rate ◽  
Optimum Operating Condition ◽  
Fluidization Velocity ◽  
Solid Circulation Rate

Particle Image Velocimetry (PIV) and Digital Image Analysis (DIA) were used to investigate the evolution of multiple inlet gas jets located at the distributor base of a two-dimensional fluidized bed setup. Experiments were conducted with varying distributor orifice diameter, orifice pitch, particle density, particle diameter, and fluidization velocity to understand the motion of particles in the grid-zone region of a fluidized bed. Results were used to develop a phenomenological model that quantifies the conditions throughout the entire grid-zone. The results and the model were further analyzed to understand the effect of operating conditions on the solid circulation dynamics of a multiple jet system fluidized bed. It was determined that the solid circulation rate increased linearly with an increase in the fluidization velocity until the jet system transitioned from isolated to an interacting system. The solid circulation increased at a much lower rate in the interacting system of jets. This sudden change in the solid circulation rate has not been reported in the literature possibly due to the lack of multiple jet studies. For multiple jet systems, this phenomenon may indicate the presence of an optimum operating condition with high circulation rate and low air input in the bed.

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