3 ms·

Does anyone know why forward osmosis (e.g. https://www.youtube.com/watch?v=R63zYZZuRvQ https://www.youtube.com/watch?v=R63zYZZuRvQ) hasn't taken off yet? It see

• jjoonathan 11y ago
  Sure, if you don't account for the energy needed to form the high-energy carbon and nitrogen compounds ("special salts") in the first place. In practice the "special salts" are either a very low efficiency fossil fuel (if you dig them out of the ground) or a really roundabout and inefficient way to spend other forms of energy. The Haber process reduces N2 and plants reduce CO2, giving you the "special salts" (energy inputs: H2 and pump pressure for Haber, sunlight for plants). Then you burn the high-energy nitrogen+carbon compounds back into N2, H2O, and CO2 to remove them from the "forward-osmosis" solution. The sunlight, H2, and mechanical work used to create the special salts could almost certainly be used more effectively to generate electricity for reverse osmosis or distillation.
  • leot 11y ago
    But in the video I shared, it's claimed that the fancy salts can be entirely reused, and that extracting them takes relatively little energy. Thus their ongoing energy impact, and the longer-term impact of their initial cost should be relatively low, no?