Salt-Gradient Desalination Wick

Edge of Knowledge uncertainty acknowledged

Core Hypothesis

A desalination process can be driven by a maintained salt concentration gradient across a porous wick structure, where capillary transport and low-grade thermal input promote preferential vapor transport while inhibiting bulk salt crossover.

The system relies on established physical mechanisms—osmotic gradients, capillarity, evaporation, and diffusion—without pumps or active pressure differentials.

Physical Mechanisms in Use

  • Capillary-driven liquid transport through a porous wick
  • Salt-gradient-induced vapor pressure differentials
  • Localized evaporation at the warm interface
  • Condensation and collection on the low-salinity side

What Is Known

  • Capillary wicks can sustain continuous liquid transport without external energy input.
  • Salt concentration gradients alter vapor pressure and evaporation dynamics.
  • Low-grade heat (solar or waste heat) can sustain steady evaporation in thin porous media.

What Is Uncertain

  • Long-term salt accumulation and crystallization within the wick structure
  • Stability of the gradient under continuous operation
  • Effective flux limits at practical temperature differentials
  • Membrane or wick wetting leading to salt breakthrough

Failure Modes

  • Salt crystallization blocking capillary pathways and halting flow
  • Gradient collapse due to insufficient evaporation or excessive back-diffusion
  • Thermal losses overwhelming evaporation gains
  • Mechanical degradation or fouling of the wick material

Test Directions

  1. Construct a bench-scale wick assembly with controlled salt concentration on the feed side.
  2. Apply low-grade thermal input (solar simulator or heated plate).
  3. Measure mass flux, salt concentration crossover, and temperature gradients over time.
  4. Observe and document salt deposition, wick degradation, or flow interruption.

Why This Is Published Here

This system is published at the Edge of Knowledge because its feasibility depends on interacting gradients and degradation modes that are not fully characterized at operational timescales.

The intent is not to claim performance, but to expose mechanisms, uncertainties, and failure paths clearly enough that the concept can be validated—or disproven—by direct experimentation.