Search results for " Osmo"

Thermodynamic characterisation of novel solutions for closed-loop reverse electrodialysis

2018

Closed-loop reverse electrodialysis is a novel technology to convert low-grade heat directly into electricity. It consists of a reverse electrodialysis unit coupled with a regeneration unit in which the waste-heat is used to restore the initial conditions of the two solutions. One of the most impor- tant advantages of closed-loop system is the possibility to select an ad-hoc salt solution to obtain high efficiency. In this regard, it is important to assess how the salt solution properties affect the performance of the energy generation and solution regeneration processes. The aim of this study is to analyse the effect of thermodynamic properties of non-conventional salt solutions within a R…

Seawater desalination : state of the art on conventional technologies

2009

Le tecnologie utilizzate negli impianti di dissalazione

2009

Optimization of Osmotic Desalination Plants for Water Supply Networks

2016

Water scarcity and the poor quality of water resources are leading to a wider diffusion of desalination plants using the Reverse Osmosis (RO) process. Unfortunately, the cost of a cubic meter of fresh water produced by an RO plants is still high and many efforts are in progress to increase the efficiency of the membranes used in osmotic plants and to limit the energy required by the process. A further reduction of the energy cost could be obtained by an optimal operation of the desalination plant so reducing the hourly energy cost, or by coupling the RO plant with an energy production plant based on direct osmosis (Pressure Retarded Osmosis PRO). The economic viability of the desalination p…

Consensus based distributed estimation of biomass concentration in reverse osmosis membranes

2015

The correct estimation of biofilm formation in industrial environments, such as reverse osmosis plants, has become a topic of great interest. The occurrence of this natural process is the cause of huge economic losses due to a decrease of performance and maintenance costs in these plants. Current solutions based on water pretreatment or the dozing of biocides are not effective due to the lack of information about the state of the biofilm in the water system. In this work, we propose the use of a wireless sensor network that, based on the measurement of the biofilm thickness growth at the substratum of each sensor, estimates the biomass concentration within the biofilm, and, eventually, the …

Performance evaluation of CHCP hybrid seawater desalination plants

2007

There are many ways to improve efficiency and reduce fresh water cost in desalination plants, like the integration of two or more desalination systems into a hybrid mechanical/thermal lay-out. Most common results that could be achieved by hybrid systems are savings in pretreatments, overall cost reduction and significant primary energy savings, especially when cogeneration unit are concerned. In this paper a small size (2000 m 3 /day) thermal desalination system (MEE) is coupled with a single-stage seawater reverse osmosis (SWRO) system; the system is fed by a natural gas (NG) reciprocate engine, where heat is recovered both from exhaust gases and from the cooling jacket water circuit. Tech…

A critical assessment of desalination operations in Sicily

2005

In this paper a brief history of desalination plants in Sicily is presented together with an in-depth description of processes and operating data, relevant to the plants actually operating on the island. 5 multi stage flash (MSF) units and one reverse osmosis (RO) plant are operating in Gela (total nominal production of about 80,000 m 3 /d), thus providing drinking water for more than 300,000 people living in the southern coast of the island. A thermal vapour compression multiple effect distillation (TVC-MED) plant (36,000 m 3 /d) is operating in Trapani and a small mechanical vapour compression (MVC) unit (5000 m 3 /d) is located in Porto Empedocle. In the oldest MSF units in Gela, several…

Energy saving with MSF-RO series desalination plants

2003

Two major techniques are commercially used in different parts of the world: distillation and membrane processes. The dominant distillation process is multi-stage flash (MSF), and the main membrane process is reverse osmosis (RO). Although cost factors vary by site, the total cost of producing potable water from seawater with the RO process is today usually less than thermal desalting processes and the economic advantages of RO vs. evaporation process, such as MSF, are responsible for the rapid increase in use of seawater RO. In many countries both RO and MSF processes are operating. Reduction in product water cost could be achieved when a hybrid MSF-RO system is used, instead of a parallel …

Energy saving in two-stage reverse osmosis systems coupled with ultrafiltration processes

2005

In this paper the optimization of the main design parameters is performed for a double-stage seawater reverse osmosis (SWRO) system coupled with an ultrafiltration process; the minimal energy consumption is the goal of the optimization process. The energetic benefits for the membrane process are calculated, deriving from the use of a hybrid two-stage/two-pass lay-out with ultrafiltration pre-treatment, which is a typically a low energy consumption process. Also the benefits on membranes’ efficiency and duration are assessed by examining the very low Silt Density Index (SDI) of the water exiting the ultrafiltration section. The analysed system includes a SWRO membrane in the high pressure st…

A Review of the Water Desalination Technologies

2021

Desalination is commonly adopted nowadays to overcome the freshwater scarcity in some areas of the world if brackish water or salt water is available. Different kinds of technologies have been proposed in the last century. In this paper, the state of the mainstream solutions is reported, showing the current commercial technologies like reverse osmosis (RO), Multi-Stages Flash desalination (MSF) and Multi-Effect Distillation (MED), and the new frontiers of the research with the aim of exploiting renewable sources such as wind, solar and biomass energy. In these cases, seawater treatment plants are the same as traditional ones, with the only difference being that they use a renewable energy s…