Initial validation of a reverse osmosis simulator (original) (raw)
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Full-Scale Seawater Reverse Osmosis Desalination Plant Simulator
IFAC-PapersOnLine, 2020
Reverse Osmosis (RO) is an evolving membrane-based technology for water desalination that started to gain increased popularity in the light of the increased global water demand due its high efficiency and low carbon footprint. This paper presents a full-scale Seawater Reverse Osmosis (SWRO) desalination plant simulator using MATLAB/Simulink, which is a user-friendly and commonly used simulation software. The simulator has been validated using the operational data from a local plant and it allows simulating the system behavior under different operating conditions with high flexibility and minimal cost. It can be used to analyze the plant performance under different operating conditions, and for research for health monitoring applications and in the cybersecuity area.
Modelling, simulation and advanced control of small-scale reverse osmosis desalination plants
Over the last few decades, desalination has become an effective technique to produce drinkable water, from sea and brackish water, in regions where the fresh water availability is insufficient to fulfil the water demand. From the nineties onwards, Reverse Osmosis (RO) has become the most popular technology for desalination. This is because the RO desalination plants require less energy, investment cost and maintenance than other alternative desalination processes. Around 50% of the plants operating, and most plants under construction, are based on RO technology. This thesis is focused on the modelling, simulation and advanced control of one particular type of RO desalination plants: small-scale plants situated in remote areas. Typically, these plants are powered by renewable energies (such as solar panels and wind turbines) and provide drinkable water for small villages and settlements. They are very popular in arid or semi arid regions, where there is an important availability of solar radiation and wind, such as the Maghreb and the South of Europe. The correct operation of these plants fulfils the water demand and optimizes the use of the renewable energy. Besides, the advanced control deals with other issues, such as the minimization of the consumption of chemicals, the minimization of the volume of stored water, the scheduling of the stops and cleaning of the plant, the design of fault detection tools, etc. The first part of this thesis deals with the modelling of RO desalination plants. In line with this thesis, a dynamic simulation library was developed for RO desalination plants. This library is based on first principles, physical and chemical equations and correlations from the literature. It can be used for different purposes, such as the comparison of control strategies, optimization of variables, testing, capacity design, parameter estimation, data reconciliation, etc. Some of the vi SUMMARY components of the library were validated using an RO pilot plant. The second part of this thesis deals with the advanced control of RO desalination plants, powered by renewable energy. The advanced control was done using the developed simulation library, and it covers several issues, such as the model-based predictive control, the integration of process design and control, the economic optimization of the energy consumption and the cleaning scheduling, etc. The third and last part of this thesis deals with the multi-scale modelling of the RO membranes, which are the core of the RO desalination plants. In particular, the dynamic development of the salt gradient, which takes place in the boundary layer close to the membrane surface, was modelled. This modelling approach presents several improvements over other modelling strategies.
MODELING, SIMULATION AND OPTIMIZATION OF A REVERSE OSMOSIS DESALINATION PLANT
Trans stellar journals, 2021
Reverse osmosis modeling and simulation is essential in the design of a seawater reverse osmosis desalination plant. Proper procedures will result in designs that will help engineers and designers to come up with optimized plants. This article gives modeling, simulation and optimization of the V & A desalination plant located in Cape Town, South Africa. Mathematical modeling was assumed to be following the basic principles and equations of mass and transport theory. Simulation and optimization were accomplished using Water Application Value Engine simulation software. The optimization results showed a 7.3 % improvement in specific energy consumption (SEC) and about 18 % improvement in permeate productivity using the same membranes, recovery rate and feed total dissolved solids.
Analysis and simulation of a reverse osmosis unit for producing drinking water in Morocco
International Journal of Cloud Computing
Desalination becomes an imperative solution to provide drinking water from sea water and brackish water. Reverse osmosis process is now well-developed and currently dominating the desalination market. The problem with reverse osmosis and membrane filtration in general is membrane fouling that occurs with the accumulation of matter on membrane surface. Several parameters can be monitor to indicate membrane fouling such as flow rate, the pressure drop, and the permeate conductivity. In this work, the desalination process is done on a salty surface water located in Middle Atlas of Morocco, characterized by a chloride content of 295 mg/L and a variable quality depending on the seasons. Actually, surface water composition depends on atmospheric deposition and rock-water interaction. Indeed, the monitoring of river quality confirmed that the characteristics of the raw water are not stable according to weather conditions. The recorded measurements clearly show that the minimum value of conductivity was recorded during winter season due to the rainfall dilution process and increases during the summer season due to the evaporation of the water. The questioning of water quality variation over the seasons initiated to make then several simulations of the design of reverse osmosis system with two different water quality: The first quality is characterized by a conductivity of 1230 µS/cm and was recorded in winter and the second one is characterized by a conductivity equal to 3013 µS/cm that was recorded in summer and it is the water quality that was taken into account for the design of the reverse osmosis plant. The results of those simulations shown a better recovery rate compared with what was initially expected: 88% for the first less salty quality versus 78% for the quality taken into account for the reverse osmosis plant design. This is also reflected in the energy consumptions that decreased by 0.09 kWh/m 3 .
Process simulation of modelled reverse osmosis for desalination of seawater
Water Practice and Technology, 2021
Model equations for prediction of process parameters of reverse osmosis for desalination of seawater were developed via mathematical derivation from basic equations for the reverse osmosis process. A model equation relating the interfacial solute concentration () with the process pressure difference () was developed. Taking the of reverse osmosis as the basic independent variable, further model equations relating other process parameters such as the solute concentration polarity , water flux , osmotic pressure , water output rate (q), power density (Pd) and specific energy consumption (SEC) were developed. Simulation of hypothetical reverse osmosis data using Microsoft Excel Worksheet and Microsoft Windows 10 on a 64-bit operating system was carried out. Simulation results showed that the optimum fluid bulk concentration was = 0.0004 mole/cm3. The optimum rate of increase in the solute rejection factor per unit rise in ΔP was 0.45%. The optimum solute rejection factor was 97.6%. The...
Modelling and Optimization of Reverse Osmosis Desalination Plants
International Journal of Mechanical Engineering and Technology (IJMET), 2019
Research on the modelling and optimization of reverse osmosis (RO) desalination plants is ongoing in order to come up with sustainable and efficient RO plants. Several techniques have been employed to come up with mathematical models of mass and heat transfer, salt rejection and membrane solute permeability, including genetic algorithms (GA) and neural networks techniques. Incorporation of PID controllers have been well known and widely used to improve the dynamic response as well as to reduce or eliminate the steady state errors and improve responses.
Modeling and Computer Simulation of Reverse Osmosis System for Water Treatment
Romanian Journal of Petroleum & Gas Technology, 2021
Water represents the essence of life on earth, so we must preserve and use responsibly this given resource. For many years, water treatment has been a field of continuous development. At the same time, new materials and techniques are being developed for one of the most important methods in water treatment: Reverse Osmosis (RO). Actual technology in this domain provided us with good know-how to reverse osmosis systems creation, simulation, and validation of the simulation results. Our duty is to bring value to this heritage with new specific cases where the known techniques will be used to create efficient models for water treatment by reverse osmosis. Reverse osmosis is mainly a method for seawater desalination which started to be used more often in industrial applications for water and other product treatment. The focus of this study is to design and simulate a reverse osmosis system with the help of Q+ Projection software v3.1 for a 10 m 3 /h well water flow by using different types of membranes, in order to select an appropriate membrane which will provide the best parameters for permeate water. Permeate water resulted after reverse osmosis treatment will be used as process water for spirit drinks production.
Review on modelling and control of desalination system using reverse osmosis
Reviews in Environmental Science and Bio/technology, 2011
Dissolved salts in seawater or brackish water are reduced to a potable level through separation techniques, like, distillation, multiple effect vapor compression, evaporation, or by membrane processes such as electro-dialysis reversal, nano-filtration, and reverse osmosis (RO). RO is the most widely used desalination process. Recent advances in RO technology has led to more efficient separation and now is the most cost effective process to operate. The performance of the reverse osmosis process is dependent on concentration of dissolved solids in the feed-water, feed-water pressure, and the membrane strength to withstand system pressure, membrane solute rejection, membrane fouling characteristics, and the required permeate solute concentration. RO is a promising tool that uses cellulose acetate (or) polyamide membrane and is widely chosen as the cost of production is reduced by the use of energy efficient and process control techniques. This paper presents a review on modelling, identification of parameters from single input-outputs and multi input/output lumped systems, dynamic modelling and control of desalination systems in the past twenty years by collecting more than 60 literatures.
2017
Despite being a mature process, production of fresh water using desalination is still a challenge. Desalination is broadly divided into two categories; thermal desalination processes, such as multi-stage flash, and semi- permeable membrane process, such as Reverse Osmosis (RO). This work is aimed at developing correlations for water permeability coefficient (Kw) and salt permeability coefficient (Ks) as a function of feed salinity and pressure using experimental data for a continuous RO process. For three different feed salinities of 15, 25, and 35 g/L at two different pressures of 40 and 45 bara experimental values of Ks and kw values are taken from the literature. Planar and ellipsoidal least square methods are used to correlate kw and Ks as a function of feed salinity and pressure, which are then embedded within the continuous RO process model to evaluate the process performance in terms of maximising the recovery ratio while optimizing the area and pressure to get the desired fr...
Simulation and Optimization of Full Scale Reverse Osmosis Desalination Plant
Computer Aided Chemical Engineering, 2010
This paper focuses on steady state performance predictions and optimization of the Reverse Osmosis (RO) process utilizing a set of implicit mathematical equations which are generated by combining solution-diffusion model with film theory approach. The simulation results were compared with operational data which are in good agreement having relative errors of 0.71% and 1.02%, in terms of water recovery and salt rejection, respectively. The sensitivity of different operating parameters (feed concentration, feed flow rate and feed pressure) and design parameters (number of elements, spacer thickness, length of filament) on the plant performance were also investigated. Finally a non linear optimization framework to minimize specific energy consumption at fixed product flow rate and quality while optimizing operating variables (feed flow rate, feed pressure) and design parameters (height of feed spacer, length of mesh filament). Reduction in operating costs and energy consumption up to 50 % can be reached by using pressure exchanger as energy recovery device.