Process simulation of modelled reverse osmosis for desalination of seawater

Model equations for prediction of process parameters of reverse osmosis for desalination of seawater were developed via mathematical derivation from basic equations for reverse osmosis process. A model equation relating the interfacial solute concentration () with the process pressure difference () was developed. Taking the of a 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 a hypothetical reverse osmosis data using Microsoft Excel Worksheet and a 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 optimum water output rate, specific energy consumption and power density were 103.2 L/h, 3.65 kWh/m3 and 6.09 W/m2, respectively.

Experimental investigation of simultaneous effect of parabolic trough collector and flat external reflectors on performance of stepped solar still

In this research, the performance of stepped solar still has been experimentally evaluated. For this purpose, a parabolic trough collector has been used to preheat the saline water entering the solar still. Also, two flat external reflectors have been employed to increase the amount of solar energy received by the steps and the collector of the system. The findings of this research indicate that the use of two flat external reflectors is more effective than using the trough collector. Also, it is more efficient to apply both mechanisms simultaneously than to use them separately. According to the obtained results, the distilled water output of the solar still is 760, 1,560, 2,440 and 2,760 ml/m2, respectively, for operating the conventional solar still, using the trough collector, using the two flat external reflectors, and using the collector and reflectors simultaneously. The electrical conductivity due to the presence of salt and chemical substances dissolved in the distilled water discharged from the still is 255, 215, 62 and 38 micro Siemens per centimetre, respectively, for each of the four mentioned cases. These experiments show that by applying the proposed mechanisms, the amount of distilled water can be increased, and its purity can be enhanced.

Experimental and numerical evaluation on performance of potable water productivity with rectangular fins basin triangular solar still

Demand and conservation for potable water has become a foremost concern world-wide. Many technologies were adapted for converting the saline water to potable water to meet the required demand on water conservation. In the current research work triangular solar still with rectangular-fins attached to the basin is proposed to enhance the output of potable water from the solar still setup. Solar still with and without rectangular-fins on the basin are fabricated for experimental comparison and evaluation in addition to numerical investigations. Thermal Performance, instantaneous efficiency and potable water output of the proposed solar still & base solar still are investigated during March month for the location of Sathyamangalam. Investigation shows enhancement of water production in the proposed solar still by 41% higher compared to the base still. The maximum distillate output from modified still and base still for a typical day is 3.1 liter and 2.2 liter respectively.

Performance Improvement of Solar Still with and without Use of PCM

Water problems are same in worldwide. Mainly it is faces by rural area peoples. Mostly drinking water is available from wells and rivers. Because of high population and industrialisation this water might be contaminated with harmful substances such as bacteria and therefore unsafe drinking water. Purification of water by solar is most useful and economic and safe solution. Solar still are mostly useful in rural and tribal area to provide clean water. Solar water still easy to construct, output depend on type of model. And it is operated by unskilled person easily no hard maintenance required and no operational cost and are also clean and safe process and no any type of pollution spread by this process. In this experimentation work comparison is to be made between with and without use of phase change material. It is observed that use of latent storage in solar still will increase water output.

Spatio-Temporal Assessment of Global Gridded Evapotranspiration Datasets across Iran

Estimating evapotranspiration (ET), the main water output flux within basins, is an important step in assessing hydrological changes and water availability. However, direct measurements of ET are challenging, especially for large regions. Global products now provide gridded estimates of ET at different temporal resolution, each with its own method of estimating ET based on various data sources. This study investigates the differences between ERA5, GLEAM, and GLDAS datasets of estimated ET at gridded points across Iran, and their accuracy in comparison with reference ET. The spatial and temporal discrepancies between datasets are identified, as well as their co-variation with forcing variables. The ET reference values used to check the accuracy of the datasets were based on the water balance (ETwb) from Iran’s main basins, and co-variation of estimated errors for each product with forcing drivers of ET. The results indicate that ETERA5 provides higher base average values and lower maximum annual average values than ETGLEAM. Temporal changes at the annual scale are similar for GLEAM, ERA5, and GLDAS datasets, but differences at seasonal and monthly time scales are identified. Some discrepancies are also recorded in ET spatial distribution, but generally, all datasets provide similarities, e.g., for humid regions basins. ETERA5 has a higher correlation with available energy than available water, while ETGLEAM has higher correlation with available water, and ETGLDAS does not correlate with none of these drivers. Based on the comparison of ETERA5 and ETGLEAM with ETwb, both have similar errors in spatial distribution, while ETGLDAS provided over and under estimations in northern and southern basins, respectively, compared to them (ETERA5 and ETGLEAM). All three datasets provide better ET estimates (values closer to ETWB) in hyper-arid and arid regions from central to eastern Iran than in the humid areas. Thus, the GLEAM, ERA5, and GLDAS datasets are more suitable for estimating ET for arid rather than humid basins in Iran.

Demonstration of MEOR as an alternative enhanced oil recovery technique in Nigeria offshore oilfield

Eni oilfield has been experiencing production decline with increase in water output. The implementation of enhanced oil recovery (EOR) can help to extract some percentages of the original oil in place (OOIP). EOR methods are capital intensive and few are environmental hazardous. In a bid to address these issues, this paper discusses on an alternate economically viable enhanced oil recovery technique which has the potential to curb the challenges of other conventional EOR methods.This work suggested a 3 stage approach of applying microbial enhanced oil recovery (MEOR) method for oil recovery in Eni field. The reservoir characteristics in Eni field were studied, the average porosity value of the reservoirs is between 0.238 and 0.241.The reservoir characteristics and parameters were found suitable for the application of MEOR technique for effective oil drainage from the delineated reservoir compartments. Microbial flooding was found to be matured in reservoirs with temperature less than 200 F, brine salinity not more than 100,000 ppm, water depth not more than 3500m and permeability should be above 30 (Md). It was recommended that MEOR approach should be applied in Eni Oilfield for increment of oil production and reduction in water cut due to its efficiency and economic viability.

Sensitivity Analysis of N Undistinguishable Photovoltaic Thermal Compound-Parabolic-Concentrator Collectors (Partly Covered, 50%) Integrated Single-Slope Solar Distiller Unit

In the current research, the sensitivity analysis of N alike in parts covered photovoltaic thermal compound parabolic concentrator collectors integrated single-slope solar distiller unit is performed and examined. The analysis is done using computational programming in matlab (month: May and location: New Delhi). The parametric values of potable water and DC electric power outputs have been figured for different values of mass flow rate (MFR), number of collectors (N), packing factor (PF), and water depth (WD). Elaborative observations says that the value of potable water output declines and DC electric power output increases with the increase in MFR for the considered values of N, PF, and WD. Also the values of DC electric power increases by 81.63% if packing factor is increased from 0.4 to 0.6 for the considered values of MFR, N, and WD. Based on the results of all the analysis, sensible and effective conclusions are made.