Search results for "Desalination"

Eulerian–Lagrangian modeling and computational fluid dynamics simulation of wire mesh demisters in MSF plants

2016

Abstract This study focuses on computational fluid dynamics model (CFD) for simulation of demisters in multistage flash desalination (MSF). The Eulerian–Lagrangian model (steady-state and two-dimensional) was developed to simulate the demister. The model was used to simulate the flow of water vapor and brine droplets in the demister. The computational domain includes the following three zones: the vapor space above the demister, the vapor space below the demister, and the demister. The demister zone was modeled as tube banks. A sensitivity analysis of the model revealed that vapor velocity is the main parameter that affects demister performance. Additionally, the analysis indicated that vap…

Exergy analysis of electrodialysis for water desalination: Influence of irreversibility sources

2022

The increasing freshwater demand is pushing the development and adoption of desalination technologies. In this framework, electrodialysis has a consolidated role in brackish water desalination, but to make it competitive with other technologies for the desalination of more concentrated solutions (e.g., seawater), the specific energy consumption should be reduced. Exergy analysis provides a useful tool for determining the contribution of each thermodynamic inefficiencies on the process efficiency and the specific energy consumption. In this regard, this paper presents an exergy analysis of the electrodialysis process. A 1-D model is used for evaluating the performance of industrial-scale sys…

Societal and economic aspects of a novel circular system for the valorisation of desalination brine and waste heat from a power plant

2022

Direct disposal of concentrate brines produced in industrial plants can have a relevant impact to environmental systems. For this reason, brine treatment and valorisation could help to avoid disposal and produce marketable salts, thus representing a possible economic benefit. With this aim, a novel process, where advanced separation technologies are combined with waste heat recovery, is proposed within the EU-funded WATER MINING project. The Case Study presented in this work concerns the power plant in Lampedusa island, where waste heat and desalination brine are available to implement the process via a pilot plant to be installed for alternative thermal treatment of the brine. The aim is t…

A feasibility study of table salt production from seawater reverse osmosis brine

2022

Zooming on the exergetic cost formation process of a Multiple-Effects-Evaporation (MEE) desalination plant

2009

In this paper an advanced energetic and thermoeconomic analysis of a Multiple Effect Evaporation (MEE) process is proposed. Starting from the thermochemical fundamentals of desalination processes, a minimum theoretical work of separation is introduced, to be used as reference condition to assess the efficiency of desalination units. The attention is then focused on a forward feed MEE configuration; by abandoning the usual perspective oriented to analyse the system at an “overall plant” level, a zooming strategy is proposed to understand in depth the margins for systems’ improvement. Focusing on a single effect, different subprocesses and their mutual interactions are correctly recognized to…

Exergy analysis and thermoeconomic cost accounting of a CHP steam cycle integrated with MED-TVC desalination

2016

In this paper exergy analysis and thermoeconomic cost accounting of a CHP steam cycle integrated with MED-TVC plant is performed; the purpose is to show how this methodology provides a rational criterion to allocate production costs on electricity and freshwater. After a brief overview on methodology and a description of reference plant, exergy analysis is carried out in order to calculate exergy flows and plant exergetic performance. A detailed description of the adopted thermoeconomic model is given. Cost accounting is performed considering two scenarios: in the first, the concentrated brine is disposed back to sea, thus being its exergy content definitively wasted; in the second, convers…

Seawater desalination : state of the art on conventional technologies

2009

Desalination by sea wave in small islands: The case of study of Lampedusa (Italy)

2018

The paper analyses the theme of water energy nexus, investigating a specific industrial process: desalination. In particular, the paper reports a case of study, applied in the small island of Lampedusa, located at south of Sicily (Italy). As the many small islands in the middle of the Mediterranean Sea, Lampedusa presents a small electrical grid, not connected to the mainland. The electrical production is entrusted to old diesel engines, consuming fossil fuel, transported by boat from Sicily. Besides, the renewable energy sources are extremely underdeveloped in this territory, since the environmental constraints make complex the use of technologies, like wind turbines or photovoltaic panels…

Desalination of oilfield produced waters via reverse electrodialysis: A techno-economical assessment

2023

Produced waters (PWs) are oilfield waste streams rich in minerals and hydrocarbons whose production rate is largely increased in last decades following the corresponding increase of energy demand. The high salinity level of PWs inhibits the adoption of cheap biological treatments. Also, desalination techniques based on osmotic membranes would require severe pre-treatments. As an alternative, Reverse ElectroDialysis (RED) and Assisted Reverse ElectroDialysis (ARED) are here proposed for the first time to reduce the salinity level of PWs. RED may also guarantee an operation cost reduction thanks to its energy generation. An ad-hoc model for RED and ARED is here developed in order to deal suit…

Desalination in small islands: the case study of Lampedusa (Italy)

2018

Desalination represents a common solution to overcome the water scarcity in small island. A case study is presented, considering the island of Lampedusa, located at south of Sicily (Italy). As many small islands in the middle of the Mediterranean Sea, Lampedusa presents a small standalone electrical grid, entrusted to old diesel engines. For more, the renewable energy sources are extremely underdeveloped in this territory. Lampedusa is regularly affected by water scarcity, so freshwater is produced by desalination plant and sometimes transported by boat from Sicily. As sustainable solution, the paper firstly analyses the energy demand for desalination and then proposes the installation of a…