Salt-Gradient Desalination Wick

A desalination process may be sustained 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.

This concept is admissible only as a narrow, instability-prone boundary regime. It is not a performance, scalability, or commercialization claim.

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

The governing physics is conventional. The uncertainty lies in whether these mechanisms can remain coupled, stable, and selective over operational time.

• Capillary wicks can sustain continuous liquid transport without pumping
• Salt concentration gradients alter local vapor pressure and evaporation behavior
• Low-grade heat can sustain evaporation in thin porous media

These facts support plausibility of the mechanism class, not validity of the full system.

The concept succeeds only if three conditions remain simultaneously true:

• The salt gradient remains persistent rather than collapsing
• The wick remains transport-capable rather than crystallization-blocked
• The vapor pathway remains selective enough to prevent meaningful salt breakthrough

If any one of these fails, the system reverts from desalination regime to gradient-decay or fouling regime.

• Long-term salt accumulation and crystallization in the wick
• Stability of the concentration gradient under continuous operation
• Practical flux limits at modest temperature differentials
• Wetting, flooding, or salt breakthrough across the structure

These are not secondary engineering details. They define whether the concept exists as a viable regime at all.

• Crystallization blocks capillary pathways and halts transport
• Back-diffusion collapses the maintained gradient
• Thermal losses overwhelm useful evaporation
• Fouling or degradation destroys wick continuity
• Salt crossover invalidates desalination selectivity

Partial flux is not sufficient. If salt transfer remains functionally present, the desalination claim fails.

1. Construct a bench-scale wick assembly with controlled feed salinity
2. Apply low-grade thermal input under monitored humidity and airflow
3. Measure distilled flux, salt crossover, and thermal gradient persistence
4. Track salt deposition, capillary interruption, and structural degradation over time

The system is falsified if useful vapor separation cannot be sustained without gradient collapse, salt breakthrough, or wick failure.

• No scalable desalination platform is claimed
• No industrial water-treatment viability is claimed
• No cost, throughput, or durability advantage is claimed
• No superiority over membranes, distillation, or RO is claimed

This is a boundary publication because interacting gradients, fouling, and structural decay may prevent the system from ever crossing into robust practice.

G: Gradient-preserving thermal and capillary transformations

Q: Total dissolved salt mass within the coupled system

S: The state of the wick-gradient regime — capillary continuity, gradient persistence, and transfer selectivity

Failure: collapse of S into blockage, breakthrough, or non-selective transport

Any claim of desalination validity must show that the gradient-driven wick remains simultaneously selective, transport-capable, and stable over time.

Demonstrating evaporation alone is not admissible evidence of desalination.