Distilled Water Production Research Articles

Design and Fabrication of a Multistage Solar Still With Three Focal Concentric Collectors

This research is intended to design and manufacture a multilayer solar distiller at a promising cost. The solar distiller manufactured has the same design as simple water distillers, which are based on the principle of evaporation and condensation with a different energy cycle, where the processes of evaporation and condensation are completely isolated. The obtained results showed that the amount of produced water has increased by 60% compared to the traditional solar distillers, where the system is not isolated. No catalysts were used, and the areas of the evaporation and condensation have also been increased leading to the production of distilled water under natural conditions and low cost. A comparison between the theoretical and experimental results is performed. The productivity was as follows: 8.45, 11.04, 12.20, 21.44, 18.69, 16.15, and 14.49 L/day in January, February, March, September, October, November, and December, respectively.

Designing a combinational solar water desalination system and investigation of solving sedimentation of minerals with water input from the Persian Gulf

In this research, an active combinational solar water desalination system was designed and investigated. Sea water was guided towards a solar collector and was evaporated in a glass chamber where the produced vapor was conducted towards a water cooled condenser using a compressor, thereby resulting in the production of distilled water. In the first experiment, the corrosion test was performed to investigate the occurrence of corrosion in the solar collector and the floor of the glass chamber. According to the corrosion test performed in the first experiment, the corrosion rate of copper, the galvanized sheet, and stainless steel was measured to be 21.874, 24.356, and 17.595 mm/year, respectively. In order to reduce corrosion in the system, a descaling solution (acetic acid) was used, where the results of the corrosion test for copper and the galvanized sheet in the presence of the descaling solution were measured to be 14.759 and 14.795 mm/year, respectively. Considering the closeness of the corrosion rate of the galvanized sheet and the stainless steel sheet, as well as the finished price of the sheet employed in the floor of the glass chamber, the application of the galvanized sheet is more economical than the use of the stainless steel sheet.

Analysis and performance assessment of a novel ORC based multi-generation system for power, distilled water and heat

In this paper, the coupling of a Humidification-Dehumidification Desalination (HDD) with an Organic Rankine Cycle (ORC) as a multi-generation system is proposed in two scenarios to generate power, distilled water and heat. The system is investigated from thermodynamic and economic viewpoints, and for achieving the best results, four organic fluids are examined in the ORC. In the first scenario, the outlet water of the ORC and HDD condensers are mixed and the flow enters to the HDD, as feed water. The heat of distilled water is absorbed by a water flow in a heat exchanger and mixed with the brine of HDD to heat production. In the second scenario, just the outlet water of the ORC condenser enters to the HDD, as feed water. The heat of distilled water is absorbed by a water flow in a heat exchanger and mixed with the brine of HDD and the outlet flow of the HDD condenser. The proposed multi-generation system works without external energy (heat). Results show that within four working fluids n-Octane has the best performance and scenario (II) produce more distilled water with higher recovery rate and lower cost. Also, scenario (II) produce more amount of heating flow, although with lower temperature and higher cost. Both of proposed scenarios have optimized in order to minimizing cost of distilled water; and scenario (I), based on its structure, has optimized to maximizing distilled water production and its recovery rate. Also, a multi-objective optimization is performed for both scenarios.

Robust Superhydrophobic Laser‐Induced Graphene for Desalination Applications

AbstractThe fabrication of long‐lived, durable, superhydrophobic surfaces using a manufacturable process is an important challenge for material science. Significant advances have been reported; however, many surfaces suffer from fragility, nonmanufacturable fabrication techniques, and temporal instability. Such challenges have limited commercial scale application of superhydrophobic films, including their application to water desalination where long lifetimes and durability are essential. The fabrication of controllably wettable surfaces formed from laser‐induced graphene is demonstrated in atmospheric conditions with contact angle control from 59° to 176°; representing some of the most superhydrophobic carbon surfaces ever reported. This superhydrophobicity is used to engineer a membrane with the largest pores ever reported for the energy efficient water desalination technique of air‐gapped membrane distillation. State‐of‐the‐art production of distilled water is observed, and no membrane failure or loss of superhydrophobicity is observed on a time‐scale of months—suggesting total water production capabilities well beyond anything yet demonstrated.

Experimental investigation on hybrid PV/T active solar still with effective heating and cover cooling method

A hybrid photovoltaic/thermal (PV/T) active solar still and a conventional passive solar still with single slope were designed, fabricated and experimented at three different water depths (0.05m, 0.10m, and 0.15m). For the higher production of distillate water, a nickel-chromium (NiCr) heater powered by solar photovoltaic (PV) was incorporated in the proposed hybrid active still. Solar PV module was cooled by the saline water which increases the efficiency of the solar PV as well as the distillate water production. The daily yield from the proposed hybrid active (PV/T) solar still is 6 times more than the conventional passive still. This new system of renewable energy based power and distillate water production is highly self-sustainable in the remote areas. From the experimental study it is clear that, the proposed hybrid active (PV/T) solar still gives an enhanced overall thermal and electrical efficiency, that is nearly 25% higher than the conventional passive one.

Experimental evaluation of a two-stage indirect solar dryer with reheating coupled with HDH desalination system for remote areas

In the present study, the performance evaluations of a two-stage indirect solar dryer with reheating coupled with humidification-dehumidification (HDH) water desalination systems are experimentally investigated. The distillate water production, drying the products and energy-saving represents the main objective of the present experimental work. Due to problems in the availability of distillate water and energy sources in remote areas, the proposed system represents a good option for remote areas. The proposed system consists of two sub-systems: (i) two-stage indirect solar dryer with reheating, which can use to remove the moisture contents from the plants and fruit; (ii) the HDH water desalination, which can use to production of distillate water. The experimental results show that, as the air flow increases from 50 to 75m3/h, the distillate water productivity increases from 29.55 to 42.3l/day and the moisture removal from the product increases from 8.33 to 12.37kg/day during the period 8:00am to 7:00pm. Use a two-stage dryer with reheating improved the moisture removal from the product by 71.78% in average as compared only to the first stage of drying unit. Also, the gain output ratio varies over ranges of 1.24–1.79 and 0.97–1.38 for the proposed system and the HDH desalination system only, when the airflow rate increases from 50 to 75m3/h. The gain output ratio of the proposed system improved by 29% in average as compared only to the HDH desalination system.

Novel cylindrical cross-flow hollow fiber membrane module for direct contact membrane distillation-based desalination

Direct contact membrane distillation-based desalination is attractive especially for high salt concentrations. We recently developed successfully a hollow-fiber membrane (HFM) based rectangular module with hot brine in cross-flow over the HFMs and obtained high and stable water flux under demanding scaling conditions. This module design with a low surface area/device volume is inadequate for larger-scale plants. A novel cylindrical cross-flow module containing high-flux composite hydrophobic HFMs is described for membrane surface areas, 0.15 and 0.6m2, using porous fluorosiloxane-coated porous polypropylene hollow fibers. This simple and easily-scalable module design packs four times membrane surface area/unit equipment volume compared to earlier design. Distilled water production rates from 1wt% saline feed was studied over brine temperatures of 60–91°C. A model developed to describe the observed water production rates in dead-end feed introduction configuration appears to describe observed water production rates well. Model predictions were explored for a range of HFM lengths and larger HFM ID to compare with those from rectangular modules with shorter HFMs.

Performance evaluation of a solar energy assisted hybrid desiccant air conditioner integrated with HDH desalination system

In this study, the performances of a solar energy assisted hybrid desiccant air conditioning system integrated with humidification–dehumidification (HDH) desalination system are numerically investigated. The aim of this study is to benefit from the temperature rise of the regeneration air outside of the desiccant conditioning system as well as the water vapor content in this regeneration air by feeding it to the humidification-dehumidification water desalination unit to produce distillate water. The distillate water productivity, human thermal comfort issues, and energy saving represent the main objective of the present numerical study. The simulated results developed for subsystems are validated with the published experimental results. The effects of regeneration air temperature and flow rate on supply cooled air temperature, distillate water productivity, the cooling coefficient of performance and overall daily coefficient of performance of the proposed system are investigated. The results show that (i) the distillate water productivity increases from 3.175 to 5.011L/h and overall daily coefficient of performance decreases from 4.392 to 3.636 with increasing the regeneration air temperature from 75 to 95 as (ii) the increase in the regeneration air flow rate from 70 to 130 m3/h, increases the distillate water productivity from 2.988 to 4.78L/h and decrease the overall daily coefficient of performance from 4.66 to 3.386. The study demonstrates that the proposed system represents the best options in hot and humid regions.

Performance evaluation of photovoltaic/thermal–HDH desalination system

The efficiency of photovoltaic (PV) panel drops with increase in cell temperature. The temperature of the PV panel can be controlled with various cooling techniques. In the proposed work the PV panel is cooled by circulating water and the recovered heat energy is used to run a humidification and dehumidification desalination to produce distilled water from sea water (or) brackish water. This work deals with a detailed analysis of performance of combined power and desalination (Photovoltaic/Thermal–Humidification and Dehumidification) system. A mathematical model of PV/thermal–humidification dehumidification plant was developed and simulations were carried out in MATLAB environment. The performance of photovoltaic/ thermal desalination (Photovoltaic/Thermal–Humidification and Dehumidification) system was investigated under various solar radiation levels (800–1000 W/m2). For each solar radiation level the effect of mass flow rate of coolant water (30–110 kg/h) on water outlet temperature, PV efficiency, PVT thermal efficiency, distilled water production, and plant efficiency was studied. Results show that under each solar radiation level increasing coolant flow rate increases efficiency of PV panel and reduces the plant efficiency. The highest PV efficiency (16.598%) was reached under 800 W/m2 at mass flow rate of 110 kg/h and the highest plant efficiency (43.15%) was reached under 800 W/m2 at a mass flow rate of 30 kg/h. The maximum amount of distilled water production rate (0.82 L/h) was reached under 1000 W/m2 at water mass flow rate of 30 kg/h.

Seasonal effect on solar distillation in the El-Oued region of south-east Algeria

In the present purely experimental work, we tested a solar distiller with a simple slope in the region of El-Oued located in the south-east of Algeria, during the winter then the summer seasons at the same place. Dimensions of the studied device are (1000 x 500 mm), while the depth of the water to be distilled is 1 cm, the glazing thickness is 4 mm, and the tilt angle with respect to the horizontal is 10 °.The aim of this work is to compare distillation between winter (January) and summer (May) to show that weather factors such as solar radiation, ambient temperature and humidity are influential on the distiller productivity. The amount of distilled water in winter was about 119 ml per day. However, that in summer was 1127 ml per day in total, so it is an increase of more than 9 times the production of distilled water.

Enhancement of pyramid solar still productivity using absorber plates made of carbon fiber/CNT-modified epoxy composites

This work aims to augment the distilled water productivity of a modified pyramid solar still using absorber plates made of carbon fiber/nanomaterials-modified epoxy composites. The effect of using basin absorber plates made of carbon fiber/epoxy incorporating carbon nanotubes or graphene nanoplatelets on the fresh water productivity was investigated experimentally under Jordanian climatic conditions. In this study, four similar solar stills with basin absorber plates of 0.5m2 and a pyramid glass cover have been designed and constructed by local materials. Three absorber plates were manufactured from carbon fiber/epoxy composites incorporating 2.5wt%, 5wt% carbon nanotubes and 2.5wt% graphene nanoplatelets in the epoxy matrix. Experimental results showed that adding 5wt% and 2.5wt% carbon nanotubes to the epoxy matrix in the carbon fiber/epoxy composites caused 109% and 65% increase in the amount of distilled water, respectively, when compared with the ordinary type absorber plate (black painted galvanized steel). On the other hand, the performance evaluation indicated that the amount of distilled water was increased by 30% when incorporating graphene nanoplatelets in the epoxy matrix.

Efficiency analysis of tank-type water distillation system integrated with hot water collector

In this study, besides the hot water, it was also aimed to obtain distilled water from solar still water heating systems, which are widely used in obtaining hot water. For this purpose, a new type of distiller was obtained by making modifications, which enable us to obtain distilled water, on a solar still water heating system having flat-surface panel collector and vertical tank and operating as a closed system. The designed system was tested under both natural convection and forced convection at flow rates of 30kg/h and 50kg/h. As a result of performed experiments, the temperature, productivity, and distilled water production amounts were calculated for the designed system. It was determined that the temperature of hot water obtained was sufficient for daily use. According to the results, as the highest amount of water, 1.820kg/day distilled water was obtained form also the natural convection system. In order to determine the drinkability of distilled water, the laboratory analyses were carried out, and it was found that the water meets EC standards. Thus, the clean and hot water was obtained at the same time from the designed system under real weather conditions.

Modified pyramid solar still with v-corrugated absorber plate and PCM as a thermal storage medium

A modified pyramid solar still with both v-corrugated absorbers plate and PCM, and the conventional pyramid solar still was designed, constructed and fabricated under the same ambient conditions of Tanta city, Egypt. The performance of the modified pyramid still with both v-corrugated absorbers plate and PCM (modified pyramid still with PCM) are compared to the conventional pyramid still, to describe the improvement in the performance of the modified pyramid still with PCM. The experimental results showed that the accumulated distillate yield for modified pyramid still with PCM is higher than that of conventional pyramid still. The accumulated distillate yield reached approximately 6.6 L m−2 d−1 for modified pyramid still with PCM while its value was 3.5 L m−2 d−1 for conventional pyramid still. The use of v-corrugated absorbers plate and PCM under basin improved the accumulated distillate yield of a modified pyramid still with PCM by 87.4% compared to the conventional pyramid still. Moreover, the modified pyramid still with PCM is superior in daily efficiency (86.41%–88% improvement) compared to the conventional pyramid still in the period from September to October 2016 under the Egyptian conditions. The estimated cost of 1 L of distillate water productivity reached approximately 0.0236 $ L−1 for modified pyramid still with PCM while its value was 0.0262 $ L−1 for conventional pyramid still.

Fouling in Membrane Distillation, Osmotic Distillation and Osmotic Membrane Distillation

Various membrane separation processes are being used for seawater desalination and treatment of wastewaters in order to deal with the worldwide water shortage problem. Different types of membranes of distinct morphologies, structures and physico-chemical characteristics are employed. Among the considered membrane technologies, membrane distillation (MD), osmotic distillation (OD) and osmotic membrane distillation (OMD) use porous and hydrophobic membranes for production of distilled water and/or concentration of wastewaters for recovery and recycling of valuable compounds. However, the efficiency of these technologies is hampered by fouling phenomena. This refers to the accumulation of organic/inorganic deposits including biological matter on the membrane surface and/or in the membrane pores. Fouling in MD, OD and OMD differs from that observed in electric and pressure-driven membrane processes such electrodialysis (ED), membrane capacitive deionization (MCD), reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF), microfiltration (MF), etc. Other than pore blockage, fouling in MD, OD and OMD increases the risk of membrane pores wetting and reduces therefore the quantity and quality of the produced water or the concentration efficiency of the process. This review deals with the observed fouling phenomena in MD, OD and OMD. It highlights different detected fouling types (organic fouling, inorganic fouling and biofouling), fouling characterization techniques as well as various methods of fouling reduction including pretreatment, membrane modification, membrane cleaning and antiscalants application.

Development and evaluation of plastic based solar still for production of distilled water

Solar still was developed and evaluated at Department of Renewable Energy Engineering, College of Agricultural Engineering and Technology, Dediapada. The average yield of distilled water in developed solar still varied from 1055-1498 ml/m 2 -day during winter and summer where as in already developed still varied 1350 to 1550 ml /m 2 day . Thermal efficiency of developed solar still was found as 20 per cent .The physicochemical analysis was carried out to examine the effect of distillation on tap water. A drastic reduction in the TDS, Chlorides, Calcium hardness and magnesium hardness, dissolved silica was observed through solar distillation. The payback period of the unit was only 6 months and after that period the unit produced net profit. The manufacturing cost of this developed solar still was only Rs. 1640/- which was totally manufactured in plastic material so no any corrosive material came in contact for changing the property of distilled water as output. Cleaning of solar still could be easily carried out by just removing the w shape dome of developed device which cannot be possible in available solar still in market.

Performance enhancement of modified solar still using multi-groups of two coaxial pipes in basin

The new configuration of modified solar still with multi-groups of two coaxial pipes in basin have been experimentally investigated. The effects of the thickness of annular space between two coaxial pipes are investigated. Four types of the new configuration of modified stills (Types A, B, C and D) with different annular space between two coaxial pipes were studied. A comparison between the four types of modified still with multi-groups of two coaxial pipes in basin and the conventional still are investigated. The results of the experimental study show that, the modified solar still with multi-groups of two coaxial pipes in basin enhanced the distillate water productivity by 97.8%, 77.4%, 63.6% and 52.7% for Types A, B, C and D, respectively as compared to the conventional solar still. In the modified solar still for increase the thickness of annular space between two coaxial pipes from 5 to 14.5mm, the daily efficiency decreases from 67.6% to 53.46%. The percentage increases in the daily efficiency for the modified solar still with multi-groups of two coaxial pipes in basin (Types A, B, C and D) are approximately 90.8%, 75.7%, 62.6%, and 52%, respectively as compared to the conventional solar still. The calculated cost of one liter of distillate water productivity reaches 0.02$, 0.021$, 0.023$, 0.024$ and 0.021$ for modified stills (Types A, B, C and D) and conventional still, respectively.

Experimental investigation of humidification-dehumidification desalination system with corrugated packing in the humidifier

The performance of a desalination unit using humidification-dehumidification technology with new corrugated packing aluminum sheets in the humidifier was experimentally investigated. The influences of operating variables on yield and performance are studied. Operating variables include the air and water temperature at entry to the humidifier, the humidifier water flow rate, the ratio of mass of water to air, and the cooling water flow rate into the dehumidifier. To conduct such a study, an experimental set-up was developed, including a packed bed humidifier, finned tube condenser, water heater, air heater, and other auxiliary devices. The results indicate that increasing the temperature of inlet water in the humidifier, the humidifier water flow rate, and the dehumidifier cooling water rate significantly increases the production of distilled water. However, a slight increase in the production of desalinated water is observed by raising the air temperature, while a specific air mass rate achieves the highest productivity. The inlet cooling water temperature significantly enhances the yield from 10 to 15L/h as the inlet cooling temperature reduces from 28.5°C to17°C. Cost analysis of the developed system indicates that the total cost per one liter of fresh water is about $0.01.

Parametric investigation of a vertical multiple-effect diffusion solar still coupled with a tilted wick still

A parametric investigation was performed theoretically for a solar still consisting of a vertical multiple-effect unit (MEU) and a tilted wick unit (TWU). Thermal input to MEU is the latent heat of vapor from TWU and solar radiation directly incident on MEU. Parameters analyzed in this study were the inclination angle of TWU, the ratio of the height of MEU to the length of TWU, air gap sizes in double glass covers of MEU and TWU, and the distance between the plates and number of plates used in MEU. Each parameter was analyzed to find the optimum value to produce the maximum daily production of distilled water. With optimum conditions, the total daily production of the still would be competitive with other types of multiple-effect stills. Outdoor experiment with 4-effect MEU was also performed, and it was found that the discrepancy between experimental and theoretical results was about 10%.

Single Basin Solar Still with Varying Depth of Water: Optimization by Computational Method

Solar still is a device, used to convert brackish water into distill water but the major issue low profitability and it is imperative to outline an ideal device. Computational Fluid Dynamics (CFD) simulation can help designers to improve the execution of a sun oriented still for a given cost. In this study, we examine the capacity of CFD simulation in calculation of heat and mass transfer in a single basin sun powered still. Experiments were performed in month of June in Jaipur, India. In this work, single basin solar still was fabricated and then optimized using CFD based methodology for water depth of 0.01m, 0.02m and 0.03 m. CFD based results help in a designing a solar still with maximum yield productivity of distilled water. It was concluded that maximum yield was achieved when water depth has minimum value i.e. 0.01 m. Total dissolved solid (TDS) value for sample water taken at water basin was in range of 500 PPM but after distillation water at output reaches below 50 PPM. Therefore, solar still was capable of improving the quality of water and brackish water of high TDS value can be reduced and used for drinking purpose.

Optimal Design of a Solar Desalination Unit with Heliostats

The objective is to improve the yield of a solar desalination cell using concentration of solar rays by means of automatically controlled heliostats. The vertical cell is orientated towards the north. It is mainly composed of two plates; the one being heated by the solar rays reflected by the mirrors is used for evaporation of a falling water film; the other one is used for water vapor condensation. Each heliostat consists of an altitude-azimuth mount having two degrees of freedom and supporting a plane mirror. The heliostat permanently follows the sun trajectory and reflects the solar rays on the cell by means of automatic control implemented in a control card based on a microcontroller. Model predictive control allows us to maximize the distilled water production.