From "Passive direct air capture via evaporative carbonate crystallization" (2025) https://www.nature.com/articles/s44286-025-00308-5 :

> Abstract: [...] This passive, single-chemical-loop approach has the potential to reduce capital and levelized costs by approximately 42% and 32%, respectively, compared with conventional liquid-based direct air capture systems.

What is their projected cost per ton?

From 2025-09 https://news.ycombinator.com/item?id=45282882 :

> A techno-economic analysis estimates a levelized cost of capture of ~$70/tonneCO2 [with this membraneless electrochemical approach], compared to $137/tonneCO2 for conventional EMAR

> [ $50 ]

From 2025-11 https://news.ycombinator.com/item?id=46010414 :

> I just saw $26/ton for (non-CO2) carbon capture in 2025. Gravel is like $10-$50/ton.

From 2025-: https://www.nature.com/articles/s41893-025-01696-5 :

> Using uncertainty-aware cost modelling, including membrane cost, electricity prices, contingency factors and learning curves, we show that capture costs can reach US $50–100 per ton CO2 for natural gas power plants and as low as US $25–50 per ton CO2 for coal and cement plants, positioning this technology favourably against state-of-the-art capture processes.

But then the usability of the captured carbon;

What is more reusable than CO2-derived graphene filters caked in CO2?

Given sequestered carbon in a useful form, what products can be made?