Combined geothermal heat and pressure retarded osmosis as a new green power system

Chelating agents for diluted geothermal brine reinjection

“…Those terms refer to a sustainable energy production based on osmotic gradients resulting from mixing fluids with different salinity (Madsen et al. 2020 ; Cobos and Søgaard 2020 , 2021 ). In the process of “blue energy” production, water molecules are transported spontaneously from the diluted fluid towards the concentrated saltier water due to osmotic forces.…”

“…Different schemes have been investigated (e.g., mixing of seawater with river water, desalination brine with treated wastewater, concentrated salt brine with brackish water), but it has not yet reached a commercial level (Madsen et al. 2020 ).…”

“…Madsen et al ( 2017 ) demonstrate that the PRO process can be operated at pressures up to 70 bar with power densities above 5 W/ . In a later publication, Madsen et al ( 2020 ) showed that osmotic power production can be combined with geothermal heat mining. The synergy between both systems can lead to several advantages, including reduction of the brine viscosity, coverage of the electricity that drives internal processes at geothermal plants (e.g., heat, production, and reinjection pumps).…”

“…The most well-known processes to harness this type of energy are pressure retarded osmosis (PRO) (Madsen et al 2016;Yip and Elimelech 2012), reverse electrodialysis (RED) (Lacey 1980), and capacitive mixing (CapMix) (Yip et al 2016). Different schemes have been investigated (e.g., mixing of seawater with river water, desalination brine with treated wastewater, concentrated salt brine with brackish water), but it has not yet reached a commercial level (Madsen et al 2020).…”

Cellulose Triacetate (CTA) Hollow-Fiber (HF) Membranes for Sustainable Seawater Desalination: A Review

“…Cellulose triacetate (CTA)-based hollow fiber (HF) membrane is therefore one of the commercially successful semipermeable membranes that has a long historical development due to its reliable excellent performances especially for drinking water production from seawater. In addition, recently, because of the versatile demands in energy consumption and environmental concerns about brine discharge as mentioned above, CTA-based HFs have caught attention for the usage of different methods, such as forward osmosis (FO) [ 23 , 24 , 25 , 26 ], pressure-retarded osmosis (PRO) [ 11 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ] and brine concentration (BC) [ 34 , 35 ] for the emerging technologies. Because their applications require optimum characteristics individually, different strategies for designing the membrane and module are required in spite of using the same CTA material.…”