Thermal Performance of MED-TVC Pilot at 95°C Elevated Temperature with Acid-anti-scalant Blend Treatment

Osman Hamed,Ali Al-Hamzah,Amr Mohamed Mahmoud,Ahmad Al Ghamdi,Khalid Bamardouf

doi:10.11648/j.ijmea.20210901.13

Abstract

Enhancing the efficiency of desalination plants and economics of desalinated water are the major goal to researchers. In desalination industry; Multi Effect Desalination (MED) has an economic potential which proves its maturity among different desalination technologies. Large MED plants were built and operated with satisfactory performance in the last decade. They have been operated at low temperature compared to MSF and competitive operation efficiency. The Desalination Technology Research Institute (DTRI) which belongs to the Saline Water Conversion Corporation (SWCC) of Saudi Arabia has tested MED pilot plant with hybrid acid and anti-scalant treatment to control the scale. The test was conducted under 95 °C compared to 65 TBT which the current commercial standard operational temperature and previously tested 85 TBT within DTRI-SWCC pilot plant. Increase in the TBT would allow to increase the number of effects which lead to more system efficiency (the performance ratio) and then reduce fuel consumption which reflected in water unit cost of the desalinated water. The results showed that the thermal performance including fouling factor and performance ratio was constant and have very minor degradation during the test. The good thermal performance was confirmed by the post-operation visual inspection, which revealed that the heat transfer tubes were maintained in a clean condition after testing.

Highlights

Thermal desalination has a long reputation in the market especially in Gulf region as the result of its high reliability and ease of operation through decades
Seawater reverse osmosis (SWRO) desalination technology is mainly applied to new desalination plants, because it is considered as a more cost effective compared to thermal processes [1]
During the 1990s and early 2000s, Multi Effect Desalination (MED)-TVC systems were limited in unit capacities [10], but the 15 MIGD unit of the Yanbu Phase 2 plant and the 20 MIGD unit of Al-Shoiaba plant in Saudi Arabia are examples of a modular evaporator concept which allows to build evaporators with any unit capacity considered as practical and economical [5]

Summary

Introduction

Thermal desalination has a long reputation in the market especially in Gulf region as the result of its high reliability and ease of operation through decades. Seawater reverse osmosis (SWRO) desalination technology is mainly applied to new desalination plants, because it is considered as a more cost effective compared to thermal processes [1]. Since SWRO is very sensitive to seawater conditions (i.e., clay, metal inorganics, organics and algal blooms), its performance is directly influenced by membrane fouling, leading to an increase in the O&M cost and a decrease in plant availability due to shutdowns [2]. Most thermal desalination technologies have relatively high energy consumption while those systems can be reliably operated under severe seawater conditions. Al-Mutaz describes the salient features of MED-TVC systems which makes it one of the most promising desalination technologies [5]. A MED-TVC system consumes a lower amount of electrical energy compared to the MSF technology and a conventional MED [6,7,8,9]. During the 1990s and early 2000s, MED-TVC systems were limited in unit capacities [10], but the 15 MIGD unit of the Yanbu Phase 2 plant and the 20 MIGD unit of Al-Shoiaba plant in Saudi Arabia are examples of a modular evaporator concept which allows to build evaporators with any unit capacity considered as practical and economical [5]

Methods

Results

Conclusion