Robin van Spaandonk wrote:
Reverse osmosis may superficially appear cheaper than distillation,
but in fact
it isn't if one uses one's brains. When coal is burned, 1/3 of the energy goes
into producing electricity, and 2/3 goes up the chimney. Then part of that 1/3
is used for reverse osmosis.
Yes, but RO is more efficient. That is, it takes far less energy per
gram of freshwater. Overall, it takes 4 to 30 times less than the
best mult-stage flash (MSF) distillation process. See the refs in my
book, chapter 8. MSF does produce purer water, as noted.
The large-scale Saudi plants are all hybrids, that produce both
electricity and water, very efficiently.
- Jed
