Hybrid systems in seawater desalination-practical design aspects, status and development perspectives

Hybrid systems in seawater desalination—practical design aspects, present status and development perspectives

Systematic Analysis Reveals Thermal Separations Are Not Necessarily Most Energy Intensive

Overview of hybrid desalination systems — current status and future prospects

Hybrid membrane system for desalination and wastewater treatment : Integrating forward osmosis and low pressure reverse osmosis

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 Ksand kwvalues are taken from the literature. Planar and ellipsoidal least square methods are used to correlate kwand Ksas 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 freshwater salinity. gPROMS model builder is used to simulate and optimise the process.

Both brackish water desalination and seawater desalination processes are well established and in common use around the globe to create new water supply sources. The farther the location of the source water from the ocean or seashore, the lower the salinity (TDS) of the water and the lower the osmotic pressure that needs to be overcome when desalinated water is produced. This is one of the major reasons that brackish desalination is often considered less costly than seawater desalination. A number of project considerations, however, indicate that seawater desalination can be beneficial and more cost-effective than brackish water desalination. To make a fair comparison, we need to properly compare all major aspects of both types of projects to define the best and most appropriate desalination technology. While brackish water has less feed water TDS, it is more challenging to dispose of the produced concentrate. Also, although brackish water desalination needs less energy to overcome osmotic pressure, it usually requires more energy to draw the water from the well than it takes to pump seawater from the open ocean intake. Another factor is that the temperature of the brackish well water may be lower than the temperature of ocean water, giving seawater desalination an advantage in energy demand. In comparing brackish to seawater desalination, these major aspects should be evaluated: (1) Locations of seawater and brackish water plants, relative to the major consumers of the desalinated water, (2) Transportation (pumping and disposal) costs of the feed water and produced water, (3) Potential colocation of a seawater plant with a large industrial user (e.g., power plant) of the seawater for cooling or other purposes, (4) Produced quality of brackish water and seawater desalination in terms of major minerals and emerging contaminants, (5) Sustainability of the water source: capacity and depth of the brackish water wells, as well as the type of soil. (6) Technical and economic aspects of produced concentrate disposal, (7) Permitting process costs for brackish and seawater desalination, and (8) The economics of both brackish and seawater desalination treatment processes: capital costs, operational and maintenance (O&M) costs, lifetime water cost, and total water cost (TWC). This paper discusses the major evaluation criteria and considerations involved in properly comparing the economic and technical aspects of brackish and seawater desalination to determine the more favorable desalination technology for a given desalination project.

Impact of desalination plants fluid effluents on the integrity of seawater, with the Arabian Gulf in perspective

An integral and multidimensional review on multi-layer perceptron as an emerging tool in the field of water treatment and desalination processes

Thermal desalination processes account for about 50% of the entire desalination market. The remaining market share is dominated by the reverse osmosis (RO) process. The main thermal desalination processes include multi-stage flash desalination (MSF), multiple-effect distillation (MED), and mechanical vapor compression (MVC). Other thermal desalination processes, e.g., solar stills, humidification dehumidification, freezing, etc., are only found on a pilot or experimental scale. Thermal desalination processes consume a larger amount of energy than RO; approximately the equivalent of 10–15 kWh/m3 for thermal processes versus 5 kWh/m3for RO. Irrespective of this, the reliability and massive field experience in thermal desalination keeps its production cost competitive compared to the RO process. Also, the large scale production capacity for a single MSF unit, approximately 75,000 m3/day, is sufficient to provide potable water for 300,000 inhabitants. An increase in production capacity for the MED system has been realised recently, with unit production capacities of up to 30,000 m3/day. This chapter covers various aspects of thermal desalination processes. It includes a review of design, operating, and performance parameters. The analysis for each process includes a brief review of some of the recent literature studies, process descriptions, process models, and an illustration of system design and performance analysis. The chapter is divided into two parts, the first is on evaporation processes, which includes MED and MVC, and the second is on flashing processes, which include MSF. Each section starts with a description and analysis of the individual stage, for either evaporation or flashing. This is to simplify the explanation of the main processes that takes place during evaporation or flashing. Each division gives a complete description of each desalination process, together with the main modelling equations. Performance charts are presented for each system and explained in terms of main design and operating conditions.

Seawater desalination — SWCC experience and vision

Integration of seawater desalination with power generation

Case studies on environmental impact of seawater desalination

Disinfection by-product formation during seawater desalination: A review

Energy consumption and water production cost of conventional and renewable-energy-powered desalination processes

Desalination technologies and industry have advanced significantly in the past two decades to meet the growing freshwater demands stimulated by the compounding issues of both water quality and quantity in many regions of the world. As desalination processes are energy demanding, there have been many efforts dedicated to improve energy-efficiency of the process units, enhance energy conservation and recovery, and increase renewable energy integration in desalination plants. This research-review article highlights recent key advances and discusses possible venues for further development in desalination energy portfolio to reduce specific energy consumption and, via integration with solar energy, to minimize the environmental footprint associated with freshwater production. First, an overview of current desalination technologies and their energy requirements are presented followed by a discussion on opportunities for improving energy efficiency and energy recovery in both membrane and thermal desalination technologies. Then, various combinations of renewable energy driven desalination plants are discussed with some recent highlights in solar energy driven membrane, thermal and hybrid desalination processes. Technological readiness levels for novel desalination processes, their perceived impact and expected near-future developments in renewable energy integrated desalination technologies are presented. Finally, the potential for solar driven desalination as a cost-competitive freshwater supply alternative is discussed.