Technical review, evaluation and efficiency of energy recovery devices installed in the Canary Islands desalination plants

Abstract

Drinking water supply through desalination processes based on reverse osmosis is a technology widely used in the Canary Islands due to its modular capacity and lower specific energy consumption compared to distillation technologies. The first energy recovery devices were based in centrifugal devices like the Francis Turbine. Later these devices were replaced by Pelton Turbines until the eighties when engineers developed positive-displacement devices called isobaric chambers for seawater reverse osmosis. Due to the importance of these devices in the reverse osmosis desalination process, this work analyzes, through several interviews and surveys, the main commercial isobaric chambers installed and their behavior based upon the experience of >50 years of the managers of several seawater reverse osmosis desalination plants, which are currently in operation in the Canary Islands. The purpose is to establish which of the energy recovery devices is the most suitable for installing in the future in medium and large capacity desalination plants. These results indicate the value of the factors studied: operational data, maintenance, troubleshooting and specific energy consumption of each device studied.