Selective permeation for desalination and gas separation.
Membranes selectively permeate components under driving force: pressure (reverse osmosis, nanofiltration, UF, MF), concentration (dialysis, pervaporation), electrical (electrodialysis). Flux J=L_pΔP; fouling and concentration polarisation limit performance. Low-energy, modular.
Seawater RO plants produce fresh water at ~3 kWh/m³.
Membranes separate components by selective permeation, which uses less energy in some processes such as desalination and gas separation.
Selective permeation for desalination and gas separation.
Membranes separate components by selective permeation, which uses less energy in some processes such as desalination and gas separation.
Applied pressure above the osmotic pressure forces water through the membrane while leaving most dissolved salts behind.
Build-up of material on a membrane surface that reduces flux, which must be controlled by pre-treatment and cleaning.
Typical applications include desalinating seawater with reverse osmosis, separating hydrogen from a gas stream with a polymer membrane and filtering fine particles from water with a microfiltration membrane.
Study "Adsorption" first (topic 76 of 100 in Materials & Chemical). It covers the groundwork this topic builds on.
Osmotic pressure. Rejection. Cross-flow operation.
Seawater RO plants produce fresh water at ~3 kWh/m³.
The next topic is "Filtration and sedimentation", which builds directly on this one.
It is classed as Advanced in Materials & Chemical (topic 77 of 100). It is an advanced topic. It assumes you are comfortable with the intermediate topics in Materials & Chemical.
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