Abstract: An osmotic process is disclosed. The process comprises passing a draw stream (12) and a feed stream (2), the feed stream (2) being an aqueous stream of lower salinity than said draw stream (12), through an osmotic unit (8) in which water but not salts pass from the feed stream (2) to the draw stream (12). The process further comprises passing the feed stream through an ion exchange unit (4a, 4b) in which an ion exchange process is used to treat the feed stream (2) before the feed stream (2) passes through the osmotic unit (8) and using the draw stream (12) in said ion exchange process before or after the draw stream (12) passes through the osmotic unit (8). A power generation process and an electricity generation process based on the osmotic process is also described, along with a system for carrying out the osmotic process.

Abstract: A brine saturation process is disclosed. The process comprises increasing the salinity of an unsaturated saline stream (15) by passage through a brine saturator (5) in which salt is dissolved into the unsaturated saline stream (15) to produce a high salinity stream (11); and then converting latent osmotic energy present in said high salinity stream (11) into power by passage through an osmotic power unit (20). The process further comprises using an output stream derived from the high salinity stream (11) following passage through the osmotic power unit (12) as the unsaturated saline stream (15).

Abstract: A process for solution mining of minerals is disclosed. The process comprises injecting an unsaturated stream (150) at an injection pressure into a mineral formation (130) to dissolve the mineral and extracting a high concentration stream (110) containing said dissolved mineral. The process comprising converting latent osmotic energy present in said high concentration stream into an increase in the total pressure of said stream by passage through an osmotic power unit (200) and generating electricity and reducing to the injection pressure the total pressure of a reduced concentration output stream (150) by passage through a power generating device (250) and using the reduced concentration output stream (150) at the injection pressure as the unsaturated stream (150). A process for storing a fuel in an underground formation is also disclosed.

Abstract: A power generation process is disclosed, the process comprises dissolving a solute (10) into an unsaturated stream (140) to produce a high concentration stream (130) and converting latent mixing energy present in a high concentration input stream (130) into power by passage through a power unit (20) in which the concentration of the high concentration input stream (130) is reduced. The process comprises using a reduced concentration output stream (140) derived from the high concentration input stream (130) following passage through the power unit (20) as the unsaturated stream (140). A first fraction of the high concentration stream (130) is passed to the power unit (20) for use as the high concentration input stream (130) and a second fraction of the high concentration stream (130) is output from the process.