Six columns
Four of them make tonnes. Two of them exist so that the four can be checked: one with no sorbent in it at all, one held permanently full. Neither control is ever counted toward a removal.
| Column | Role | In service | Cycles | Heel mmol/g | Note |
|---|---|---|---|---|---|
| C-4 | production | 2025-11 | 4,180 | 0.061 | The reference column. Every cycle on the front page is this one. |
| C-5 | production | 2025-11 | 3,905 | 0.058 | Run to the same schedule as C-4. Logs on request. |
| C-6 | production | 2025-06 | 6,720 | 0.079 | Oldest bed on site. The heel has been climbing since March and it is next out. |
| C-7 | production | 2026-05 | 1,140 | 0.052 | Fresh charge of BR-4, commissioned in May. |
| Blank | control | 2025-11 | 212 | 0.000 | No sorbent. Same air, same three hours, same meters. Nothing adsorbs and nothing is recovered. |
| Saturated | control | 2026-02 | 96 | 1.250 | A bed held at equilibrium with outdoor air and never regenerated. It removes nothing, for the opposite reason. |
What a column is
A steel vessel holding 82 kg of BR-4, a fan, a heater and a vacuum line. One cycle takes 210 minutes including turnaround and delivers 4.06 kg of carbon dioxide. Four of them running the year round is 40.7 tonnes, which is a small plant and we describe it as one.
The run logs below are printed the same way as the front page: the weight of each heading is the loading on that bed at that moment. On the two controls, nothing moves.