"To date, virtually all of the research
experiments on salinity gradient energy
conversion have been based on flow-
through membranes-semipermeable
membranes for pressure-retarded osmosis or ion-selective membranes for reverse electrodialysis. The difficulties
associated with use of these membranes
include high cost, degradation, polarization, and solution pretreatment requirements. In principle, however, most desalination schemes that are reversible are
capable of producing power in salination. The scheme we report here does
not require membranes. It is the reversal
of vapor compression desalination,
which has a higher thermodynamic efficiency than flash distillation, the most
highly developed desalination method"
"a power density of as
much as 7 W per square meter of heat
exchanger surface was measured for
some runs at 40°C. This value is much
higher than values obtained with membrane systems"