1. Assumptions
This document presents the LCA (Life Cycle Assessment) of an urban DAC (Air Conditioning Exhaust DAC + Wet TSA + Utilization of Urban Exhaust Temperature and Humidity + Waste Heat Reuse for Liquefied CO₂) in numerical form.
(1) Energy Consumption
✔ Wet TSA (after waste heat reuse): 0.5-0.8 × (1-0.4) = 0.30-0.48 GJ/t-CO₂
✔ Compression and Liquefaction (after waste heat reuse): 0.35-0.45 × (1-0.3) = 0.25-0.32 GJ/t-CO₂
✔ Total: 0.55-0.80 GJ/t-CO₂
This is 1/10 to 1/15 of the world's DAC (6-12 GJ/t). The Wet-TSA method, combining "urban exhaust + Wet-TSA + waste heat reuse," has the potential to become one of the world's lowest energy intensity groups.
(2) CO₂ Emissions (Electricity-derived)
When 1 GJ = 277.8 kWh, 0.55 to 0.80 GJ = 153 to 222 kWh
153 to 222 kWh × 0.45 = 69 to 100 kg-CO₂
✔ Emissions required to capture 1 ton: 69 to 100 kg-CO₂
(3) Net Reduction (Net Negative)
1000 − (69 to 100) = 900 to 931 kg-CO₂
Net Reduction Rate: 90 to 93%
This is more efficient than forest absorption and represents a reduction performance level classified as DAC credits ($600 to $1,000/t).



The LCA of liquefied CO₂ is evaluated as follows:
✔ The CO₂ in the product is "CO₂ removed from the atmosphere" → Evidence that the product itself is a "negative emission"
✔ Short transport distance (in-city production) → Significant reduction in logistics CO₂
✔ Dry ice does not emit CO₂ even when sublimated → Carbon neutral product
✔ Captures unavoidable urban emissions (from respiration) → Treated as a reduction, not an additional emission
As a result:
The environmental value per ton of product is evaluated as "net reduction (900-931 kg-CO₂)".
