How RO membrane permeability and other performance factors affect process cost and energy use: A review

This paper considers conventional Reverse osmosis processes, and the recently proposed closed-circuit RO and batch RO processes

Yoshiki Okamoto; John H. Lienhard

2019

Scholarcy highlights

  • Water scarcity has been expanding and is expected to keep expanding because of worldwide population growth, especially in developing countries .Almost 97% of the water in the world is salty and the remaining is fresh water
  • The acceptable salinity for drinking water is below 500 ppm, except for special cases in which it may rise to 1,000 ppm, and boron concentration is normally limited below 0.5 ppm
  • There is no doubt that the rate of reduction in specific energy consumption decreases as membrane water permeability increases, the rate of decrease varies depending on process conditions such as feed salinity, recovery rate, pump efficiency and so on
  • Since the chronological change of Reverse osmosis element performance due to fouling was not considered in any of these studies, these results show the relationships between membrane water permeability and the specific energy consumption at the initial operating condition
  • The review of past literature shows that the impact of membrane permeability on energy consumption varies significantly depending upon model assumptions and operating conditions
  • If the feed-side pressure loss contributes 10% of the specific energy consumption, decreasing feed-side pressure loss by half can reduce the specific energy consumption by 5%
  • In the recently-proposed batch RO processes, increasing membrane water permeability decreases the reduction of specific energy consumption, the opportunity to reduce the specific energy consumption by increasing membrane water permeability is greater in comparison to conventional RO
  • In the recently-proposed batch Reverse osmosis processes, increasing membrane water permeability decreases the reduction of specific energy consumption, the opportunity to reduce the specific energy consumption by increasing membrane water permeability is greater in comparison to conventional RO

Need more features? Save interactive summary cards to your Scholarcy Library.