Water from desert air
A passive atmospheric harvester that takes a litre of ultrapure water per kilogram of material per day out of night air, and gives it up to unconcentrated sunlight at 85 °C.
01 — the crystalWhy the step matters
Ordinary condensing dehumidifiers stall below about 50% relative humidity, because the dew point falls below freezing and there is nothing left to condense. AquaMOF does not condense water; it binds it.
The framework is aluminium 1H-pyrazole-3,5-dicarboxylate: a metal node joined by organic linkers into micropore cavities. Water clusters form cooperatively inside those pores, so uptake does not climb gradually with humidity — it completes between 10% and 20% relative humidity. That step is the whole machine. It sits inside the range where desert night air actually lives, and it means the material loads fully overnight without any energy input.
Aluminium is earth-abundant and non-toxic, and the framework resists hydrolytic breakdown over more than 10,000 continuous adsorption and desorption cycles.
02 — the cyclePassive, in two phases
No compressor, no pump and no grid connection. The cycle is the day itself.
Air passes through the porous MOF bed; vapour binds into the hydrophilic pores.
ambient 20–30 °CA sealed transparent chamber takes unconcentrated sunlight; vapour releases into the condenser.
85 °C solar heatLiquid water runs down a passive heat pipe into a sterile reservoir.
no pump, no grid03 — comparedAgainst what exists
| Metric | Refrigeration condensers | Silica gel / zeolites | AquaMOF |
|---|---|---|---|
| operating RH limit | above 50% — fails in deserts | above 35% | 10–20% |
| regeneration | compressor driven, not applicable | 160–250 °C | 85 °C, passive solar |
| electrical energy | 0.5–1.2 kWh per litre | high thermal parasitics | 0 |
| yield | stops when the dew point drops | low uptake per kilogram | 1.0+ L per kg per day |
git clone https://github.com/KELLERBABG/AquaMOF.git cd AquaMOF && cargo test cargo run --bin aquamof-sim -- rh 20 temp 30 solar-flux 850