Mechanical vapor compression desalination plants: a case-study

Abstract

Over 120 desalination plants are spread over the Canary Islands due to a scarcity of conventional water resources. These units are varied in technology and size, and accordingly a fairly good knowledge of their technology as well as experience on their operation has been developed. As a case study, The Las Palmas Port Authority desalination plant consists of two low-temperature vapour compression units, with a production capacity of 500 m(3)/d each. These units were commissioned in 1987 and 1989 and have been producing water with high levels of availability, namely average plant factors of 87.3% and 90.2%, respectively. Product water is consistently below 20 mu S/cm conductivity. Energy consumption ranges from 10.4-11.2 kWh/m(3), and the standard energy efficiency for the equipment is around 58.9% for the compressors. This report summarizes the design parameters for the system as well as its operational features.