An electricity generation process is disclosed. The process comprises injecting an aqueous feed stream into a salt formation to dissolve the salt contained therein, and then extracting a saline stream containing said dissolved salt from the salt formation. The process also comprises converting latent osmotic energy present in said saline stream into electricity by passage through an osmotic power unit comprising a semi-permeable membrane which permits the passage of water but not the passage of salts in which said saline stream is passed over one side of the semi-permeable membrane, a low salinity stream being passed over the other side of said membrane. The process also comprises using an output stream derived from the low salinity stream as the aqueous feed stream.

Membranes for membrane distillation (MD) and forward osmosis (FO) are provided with methods of manufacture and use thereof. The MD membrane comprises a microporous mat of electrospun nanofibers made of a nanocomposite comprising reduced graphene oxide dispersed in a hydrophobic polymer with their surface grafted with a silane coupling agent or with hydrophobic nanoparticles. The FO membrane comprises a microporous support layer and a rejection layer formed on one side of the support layer, wherein the support layer is a microporous mat of electrospun nanofibers made of a nanocomposite of hydrophilic nanoparticles dispersed in a hydrophilic polymer, and the rejection layer is made of nanocomposite of hydrophilic nanoparticles dispersed in a crosslinked meta-aramid of formula (I). There is also provided a process for treating a high-salinity and/or high-strength feed, such as fracking wastewater, comprising microfiltration or ultrafiltration, followed by forward osmosis, and then membrane distillation.

##STR00001##

An example separation system includes a stack of membrane plate assemblies. An example membrane plate assembly may include membranes bonded to opposite sides of a spacer plate. The spacer plate may include a first opening in fluid communication with a region between the membranes, and a second opening in fluid communication with a region between membrane plate assemblies. Adjacent membrane plate assemblies in the stack may have alternating orientations such that bonding areas for adjacent membranes in the stack may be staggered. Accordingly, two isolated flows may be provided which may be orthogonal from one another.

Embodiments described herein relate to methods and systems for dewatering solutions via forward osmosis.

Included are methods and systems for recycling a gas emitted from non-aqueous cleaning. An example method includes contacting a contaminated equipment with a non-aqueous cleaning material; wherein the spent non-aqueous cleaning material emits the gas. The method further comprises capturing the emitted gas, filtering the emitted gas, and recycling the emitted gas into the non-aqueous cleaning material.

The present invention provides for the use of recirculation loops in single- or multi-stage electrical desalination processes such as Ion Concentration Polarization (ICP) desalination and concentration processes.

A feedstock solution flow concentration system, which has a first step for counterflowing or parallel flowing a feedstock solution flow a containing a solute and a solvent b, and a draw solution flow d via a forward osmosis membrane o and transferring the solvent b in the feedstock solution flow a to the draw solution flow d to obtain a concentrated feedstock solution flow c, which is the feedstock solution flow which has been concentrated, and a diluted draw solution flow e, which is the draw solution flow which has been diluted.

A method for manufacturing a porous device (10) is described. The method comprises creating (340) a carbon nanomembrane (40) on a top surface (22) of a base material (20) having latent pores (23) and etching (360) the latent pores (23) in the base material (20) to form open pores (24). The porous device (10) can be used as a filtration device.

Described is a method for concentration and extraction of gas field chemicals. The method includes collecting produced water from a gas oil separation plant, treating the produced water to remove oil, and receiving a feed solution containing a gas field chemical and water. The treated produced water is used as a draw solution to concentrate and absorb water from the feed solution using a forward osmosis chamber. A concentrated feed solution containing the gas field chemical and a diluted draw solution is produced. The concentrated feed solution is extracted and stored for injection into gas wells.

An online cleaning system for micro-polluted nanofiltration membranes uses forward osmosis, and a process of the online cleaning system, and relates to the field of water treatment membrane separation technique. The online cleaning system includes a nanofiltration raw water tank, a nanofiltration membrane assembly, a pure water tank, a forward osmosis feed solution tank, a forward osmosis draw solution tank, a first saline water tank, a second saline water tank and a water bath temperature control device. Some embodiments include cleaning of the nanofiltration membranes that is realized by using forward osmosis as a nanofiltration membrane cleaning system, and cyclic regeneration of the nanofiltration membranes can be realized, so that the purposes of removing dissolved organic matters in micro-polluted raw water, reducing hardness of calcium and magnesium and prolonging the service life can be achieved.