Performance of a small solar-powered hybrid membrane system for remote communities under varying feedwater salinities

Abstract

An estimated 1 billion people are living both without access to clean drinking water or electricity. The small photovoltaic (PV)-powered hybrid membrane system described here is designed to address the plight of some of these people. PV and membrane technologies are chosen due to suitability for operation in remote and often harsh conditions. An ultrafiltration (UF) pre-treatment is included to remove bacteria and most pathogens, while a reverse osmosis (RO) or nanofiltration (NF) membrane desalinates the brackish feedwater. Several parameters were examined in order to optimise the system performance, including (i) feed salt concentration, (ii) operating pressure, (iii) system recovery, (iv) specific energy consumption (SEC, kWh/m3), and (v) salt retention. In addition, experiments were performed over a whole day to determine system performance under varying levels of solar radiation. The minimum SEC (relatively high due to the current single-pass mode of operation) varies from 5.5 kWh/m3 at a feed concentration of 1 g/L salt to 26 kWh/m3 at a feed concentration of 7.5 g/L salt, which is the upper limit of the system in terms of salt concentration.

Testing of a hybrid membrane system for groundwater desalination in an Australian national park

“…In comparison with the performance of other systems reported in Table 1 this system performs well with SECs below 5 W.h/L at pressures above 7 bar. The ability of the pump to maintain high flow at high pressures results in a consistently decreasing SEC, while in the previous prototype the pump limitation resulted in a minimum of the SEC at 5.5 -7 bar [10].…”

From concept to commercialisation: student learning in a sustainable engineering innovation project

“…The pump required for filtration is powered by solar energy (photovoltaics). Technical information about the system and optimisation results of various prototypes are published elsewhere (Richards and Schäfer 2002;Richards et al 2004;Schäfer et al 2004;Masson et al 2005;Richards et al 2005;Werner and Schäfer 2006;Richards et al (submitted 07/2006)). The cycle from conception of the idea to launch of the first commercial unit has been about 5 years.…”

On-Off Control Strategy in a BWRO System under Variable Power and Feedwater Concentration Conditions

“…W. Gocht et al [42] used a pilot BWRO desalination plant with a Q p capacity of 40 m 3 d −1 . A. Schäfer et al [43] carried out a performance analysis of a photovoltaic-powered hybrid BWRO membrane system considering variations in feedwater salinity. The RO system only had one membrane element and SEC variations of between 5.5 kWh m −3 at a feed concentration of 1 g L −1 salt and 26 kWh m −3 at a feed concentration of 7.5 g L −1 salt were reported.…”