Single-pass capture46.4%
Literature41.6 – 51.2 · 90% CI
Fraction of incoming CO₂ absorbed in one pass through the packing.
Interval from re-solving the march at film-coefficient multipliers 0.65-1.8 (Onda scatter, skewed high because Onda under-predicts wetting for structured fill). Chemistry uncertainty NOT included. Uncalibrated.
Transfer units0.623
Literature0.538 – 0.717 · 90% CI
Gas-phase NTU the packing delivers. Capture saturates as this grows — each unit buys less than the last.
NTU = -ln(1 - capture). Below ~0.5 the packing is too short or the air too fast; a capture well below what NTU implies means the contactor is pinching on equilibrium and more packing will not help.
Outlet loading0.206mol CO2/mol base
Literature0.206 – 0.207 · 90% CI
Loading of the solvent after ONE pass. Not the design's rich loading unless the loop is single-pass.
Loading after ONE pass. At DAC liquid-to-gas ratios this is far below solvent.richLoading, which is the accumulated loading over many recirculations - the two are not the same number and should not be compared directly.
CO₂ captured0.989mol/s
Literature0.887 – 1.09 · 90% CI
Over the whole face area.
1372.4 tCO2/yr at full uptime. Interval from re-solving the march at film-coefficient multipliers 0.65-1.8 (Onda scatter, skewed high because Onda under-predicts wetting for structured fill). Chemistry uncertainty NOT included. Uncalibrated.
CO₂ demand0.801mol/s
Assumedstated value
Nameplate ÷ capacity factor. A plant running 90% of the year must capture faster than its annual average.
plant.targetCapacity_t_per_year / capacityFactor, converted. Exact given the spec.
Fan energy73.3kWh/t
Literature33.2 – 123 · 90% CI
Shaft work per tonne captured. Roughly cubic in air velocity.
Fan shaft energy per tonne actually captured. Rises when capture falls, because the same air is moved for less CO2 - which is why an undersized contactor is expensive twice over.
Water loss4.88m3/t
Derived2.93 – 6.84 · 90% CI
Evaporated per tonne captured. A siting constraint, not a rounding error.
Cubic metres of water per tonne of CO2 captured, SIGNED. A first-class siting constraint, not a diagnostic. Negative is water GAINED, which is a purge duty, never a credit.
Packing pressure drop62.2 Pa
Pressure gradient41.5 Pa/m
Fan shaft power11,487 W
Air flow over the face120 m³/s
Onda's correlations were fitted on random packing and are known to be pessimistic for the structured fill a DAC contactor uses. Treat capture efficiency as a lower estimate.