Energy recovery through a water-hydraulic motor in a small scale RO desalination system

Energy Recovery Device with a Fluid Switcher for Seawater Reverse Osmosis System

A new approach for freshwater production and energy recovery from an oil field

The integration of water vane pump and hydraulic vane motor for a small desalination system

Mixing phenomena in an isobaric energy recovery device (ERD) of a seawater reverse osmosis (SWRO) desalination system are investigated experimentally and numerically using Particle Image Velocimetry (PIV) and Computational Fluid Dynamics (CFD). The ERD, which recovers energy from high-pressure brine discharged from RO membranes, is one of the most important mechanical devices in a SWRO desalination system. In this ERD, seawater is introduced into a vertical chamber from the top, and then high-pressure brine is introduced into the chamber from the bottom. The high-pressure brine pressurizes the seawater through direct liquid-to-liquid contact, transferring high-pressure energy of the brine to the seawater. This enables a sharp reduction in the electric energy consumption, typically 50%, of high-pressure pumps used to elevate seawater pressure for RO membranes. The energy recovery efficiency of the present ERD is over 98%, which is extremely high compared to a conventional turbine-type energy recovery device, such as a Pelton turbine, which has a system energy recovery efficiency of 60 to 80%. The possible weakness of the present ERD is the amount of mixing between brine and seawater around the direct contact surface, because mixing phenomena increase the salinity of seawater supplied to RO membranes. A higher pressure is required to keep the same amount of permeate from the membrane, which results in an energy loss in the system. To minimize mixing, a set of unique flow distributors was invented and placed at both ends of the pressure exchange chamber, which stabilizes the contact surfaces and suppresses excessive mixing. Mixing phenomena in the pressure-exchange chamber are investigated experimentally in detail with PIV and numerically with CFD, and the effectiveness of the flow distributors is clarified.

Evaluation of a pressure boosting pump/turbine device for reverse osmosis energy recovery: Extended testing on a seawater desalination system

A new dual-function device for optimal energy recovery and pumping for all capacities of RO systems

Water shortage is one of the biggest defiances in the world. Desalination becomes an essential strategy to secure fresh water. Reverse osmosis (RO) prevails the desalination market worldwide in terms of installed numbers and revenue. The fossil fuel‐powered desalination process has harmful environmental impacts and is expensive. Renewable and abundant energy sources are an auspicious substitutional for powering the RO process. This review focuses on the RO process, its classifications, challenges (including membrane fouling and large‐scale issues), integration of RO with other desalination processes, and integration with energy recovery devices (ERDs). Hybridization of RO with various renewable energy sources (RESs), focusing on solar, wind, and ocean energy, is also demonstrated, and a cost comparison between the different systems is presented. Environmental impacts and assessment of different RO systems, as well as the design of renewable power systems to operate seawater RO (SWRO) desalination systems using hybrid optimization model for electrical renewable (HOMER) software, were discussed.

A direct coupled photovoltaic seawater reverse osmosis desalination system toward battery based systems — a technical and economical experimental comparative study

The effect of energy recovery device and feed flow rate on the energy efficiency of reverse osmosis process

Titan PX-1200 Energy Recovery device — test results from the Inima Los Cabos, Mexico, seawater RO facility

In fact, current water supplies due to natural constraints or lack of infrastructure (or both) cannot be provided in a sustainable manner for all increasing and competing uses (e.g. residential, industrial, agricultural). While promoting Penghu's low-carbon islands, in a water-scarce environment, it is the motivation of this research to take into account the development of water resources and lower energy consumption costs. The seawater desalination plant water production technology is improved, the cost of water production is reduced. This research uses a genetic algorithm (GA) to optimize the recovery rate to solve the minimum Specific energy consumption (SEC) value, and then, according to the required water production, the optimal flow rate of raw seawater of the high-pressure pump is obtained, so as to minimize the energy consumption of the reverse osmosis (RO) system. The energy recovery device has a great effect on reducing the energy consumption of the RO system, and it can be seen from the results that the higher efficiency does greatly reduce the energy consumption of the SEC and water production under the different energy recovery device efficiency. Calculated using genetic algorithms, and the SEC is 3.275 and the recovery rate is 45.1%, and the water production energy consumption is 2.35 kWh/m 3 . Scheme B changed the efficiency of the energy recovery unit to 97.22%, resulting in a SEC of 1.819 and a recovery rate of 25.3%, and a water production energy consumption of 1.31 kWh/m 3 . Finally, challenges and research gaps are also proposed.

To solve the problems of high specific energy consumption and excessive harmful ions in the water production of a small reverse osmosis (RO) plant, a desalination system coupling RO and membrane capacitive deionization (MCDI) is proposed in this study. Aiming at producing two cubic meters per day of fresh water with a salt concentration of less than 280 mg L−1, parameter matching optimization was carried out on two desalination system schemes of one-stage two-section RO and one-stage three-section RO coupled with MCDI. The results were compared with the parameter matching optimization results of the one-stage one-section RO and the one-stage two-section pure RO desalination system. The results show that compared with the pure RO desalination mode, the seawater desalination mode coupled with RO and MCDI reduces the specific energy consumption under the same effluent salt concentration. Moreover, it decreases the feed water pressure in front of the RO membrane, which can reduce the standard of high-pressure pump in a small seawater desalination plant. The energy consumption of the one-stage three-section RO and MCDI coupling system is lower than that of the one- stage two-section RO and MCDI coupling system, and the feed water pressure is also lower.

Novel Tri Hybrid Desalination Plants

Based on the thermal and membrane desalination technology, this study presents an analysis of an integrated single stage TVC-RO system. The hybrid system produces fresh water with an adjustable salinity in parallel operation. A steam ejector and a pressure exchanger are applied as the energy recovery devices. For comparison, a coupling system without energy recovery process is also modeled in the steady-state condition. System performance is evaluated by specific energy consumption and production ratio. The effects of several design parameters on system performance are investigated including boiling temperature, compression ratio, motive steam pressure, and target recovery rate. Results of the analysis indicate that the product salinity is adjustable in the TVC-RO system, and the system performance is largely dominated by system configurations and design parameters. To improve the system performance, the use of energy recovery device is necessary, and the membrane operation is recommended if the process is less demanding on product purity. A better performance can be obtained by increasing the target recovery rate of the RO membrane and decreasing compression ratio and motive steam pressure of the ejector. As the boiling temperature increases, one can expect that the production rate increases at a cost of a higher specific energy consumption.

Use of simulated evaporation to assess the potential for scale formation during reverse osmosis desalination