A fertilizer gradient energy system includes a membrane module. A membrane module may include a first section and a second section. The first and second sections may be separated by a semipermeable membrane. A load may be connected to the membrane module. The first section may be configured to receive a concentrated fertilizer solution. The second section may be configured to receive a freshwater feed solution. In embodiments, a semipermeable membrane may be configured to facilitate pressure retarded osmosis of the freshwater feed solution from the first section to the second section to increase a fluid pressure in the second section. The semipermeable membrane may include an anion exchange membrane. The membrane module may include a third section. A cation exchange membrane may separate the first and third section. Anion and cation exchange membranes may facilitate reverse electrodialysis. Methods of capturing energy via a membrane module are also disclosed.

A process for the generation of power is disclosed. The process comprises receiving a wastewater stream containing organic matter and passing the wastewater stream to an anaerobic digester in which the organic matter contained therein is broken down to produce biogas. The liquid content of said wastewater stream is reduced before said stream enters the anaerobic digester by passing the wastewater stream through an osmotic power unit. The said stream is passed over one side of a semi-permeable membrane which permits the passage of water but not the passage of salts, an aqueous stream of higher salinity than said wastewater stream being passed over the other side of said membrane such that latent osmotic energy present in said aqueous stream of higher salinity is converted into electricity.

A process for generating power from a warm saline steam (1) obtained from geothermal sources. The process involves extracting a warm saline stream (1) from an underground geothermal formation (2), reducing the temperature of the saline stream (1) by passing the stream through a thermal power unit (5) in which thermal energy present in the stream is extracted. The process also involves converting latent osmotic energy present in the stream into electricity by passing the stream through an osmotic power unit (7) comprising a semi-permeable membrane (8). The output stream (13) derived from passage through the osmotic power unit is injected into a second, different underground formation.

A process for generating power from a warm saline steam (1) obtained from geothermal sources. The process involves converting latent osmotic energy present in the stream (1) into an increase in the total pressure of said stream by passing through an osmotic pump unit (7). The stream is passed over a semi-permeable membrane (8) and a lower salinity steam (14) is passed over the other side of said membrane (8), such that the need for mechanical pumping in subsequent process steps is reduced.

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.

An osmotic power generator comprising an active membrane supported in a housing, at least a first chamber portion disposed on a first side of the active membrane for receiving a first electrolyte liquid and a second chamber portion disposed on a second side of the active membrane for receiving a second electrolyte liquid, a generator circuit comprising at least a first electrode electrically coupled to said first chamber, and at least a second electrode electrically coupled to said second chamber, the first and second electrodes configured to be connected together through a generator load receiving electrical power generated by a difference in potential and an ionic current between the first and second electrodes. The active membrane includes at least one pore allowing ions to pass between the first and second sides of the membrane under osmosis due to an osmotic gradient between the first and second electrolyte liquids to generate said difference in potential and ionic current between the first and second electrodes.

An intermediate power store for at least one power generating system, including: an osmosis device, a permeate store, a concentrate store and a control device. The osmosis device is designed to separate, in a charging operation, a liquid mixture with a charging pressure into a permeate and a concentrate, or, in a discharging operation, to mix the permeate with the concentrate while applying an osmotic pressure to the liquid mixture. The permeate store is fluidically connected to the osmosis device and is designed to store the permeate. The concentrate store is fluidically connected to the osmosis device and is designed to store the concentrate. The control device is designed to control the following functions: the charging operation using electrical power from the at least one power generating system, or the discharging operation while providing electrical power.

The method p1 for converting osmotic energy into hydraulic energy and the method p2 for desalination, include pressurisation/depressurisation and isochoric washing of an aqueous solution containing a salt in the presence of a selective hydrophobic nanoporous material of which the nanoporous volume within the material is only accessible to fresh water and which has a nanoporosity volume fraction ranging from 0.2 to 1 so as to convert osmotic energy into hydraulic energy or conversely to desalinate water, preferably sea water or brine.

The present application relates to a method and a motor for performing work using osmosis. The method comprises the steps of providing a motor comprising a supply chamber, a pressure chamber comprising at least one inlet and at least one outlet, and a membrane permeable to fluid and at least partially impermeable to salt ions and enabling fluid communication between the supply chamber and the pressure chamber; then providing low salt concentration fluid in the supply chamber, closing the outlet of the pressure chamber; flowing high salt concentration fluid into the pressure chamber; allowing the pressure within the pressure chamber to increase as fluid crosses the membrane into the pressure chamber and using the increased pressure within the pressure chamber to perform work; then opening the outlet of the pressure chamber and allowing the fluid to drain from the pressure chamber and the pressure in the pressure chamber to decrease.

A system includes a power generator which provides solvent passage from one of the liquids to the other liquid by means of an osmotic membrane provided between liquids taken to a first volume and to a second volume and having different densities and which provides increasing of the pressure of the liquid to which the solvent passage occurs and which provides generation of electricity from the formed pressure. Accordingly, the system includes a first regeneration unit and a second regeneration unit, a retaining chamber, a valve unit, a first density sensor, a second density sensor, and a control unit. The control unit is configured to determine the liquid having high density in accordance with the measurements taken and to determine the operation mode of the valve unit accordingly.