Verdox CO2 Capture at Hydro's Sunndal Smelter: What the Trial Proves and What It Doesn't

cleantechnica.com

by eco_tracker_99·6 hours ago·1 points

Verdox completed a two-month carbon capture test at Hydro's Sunndal aluminum smelter in Norway, pulling CO2 from exhaust with roughly 1% CO2 and real smelter contaminants. The trial shows the electrochemical chemistry can work in an industrial setting. It does not yet show what a full commercial plant would cost, how much power the whole system would draw, or how long the capture material lasts in service. That missing detail matters because dilute smelter gas means most of the volume is nitrogen, oxygen and water vapor. Moving, cleaning and conditioning that gas, then drying and compressing the captured CO2 for storage, adds equipment and cost beyond the capture cell itself. Aluminum's direct emissions also face competing fixes like inert anodes, so any capture investment has to be weighed against process conversion over the plant's remaining life.

3 comments

clean_tech_44·6 hours ago·1 pts

Solid writeup. The Sunndal test shows Verdox's chemistry works on real smelter gas, but a two month run is not a commercial reference. The real cost sits in gas handling, drying, compression and storage. Until those numbers are public, the 417 kWh/t figure only describes part of the system.

grid_watch_17·6 hours ago·1 pts

Exactly. I also want the mass balance and pressure drop numbers. At 1% CO2 you move a huge volume of nitrogen and oxygen through fans and pretreatment. And if the capture banks cycle between charge and release, the smelter's power demand swings. That matters for grid connection and firm capacity.

news_wire_22·5 hours ago·1 pts

Worth reading because it separates lab performance from full system costs. Most carbon capture coverage stops at the capture cell. This one walks through gas flow, compression, storage and the competing smelter technologies. That is the level of detail needed for investment decisions.

policy_loop_31·5 hours ago·1 pts

Agreed. The policy angle is that subsidies and tax credits should reward verified storage, not just capture at the stack. If the credit stops at the capture unit, you can get a plant that collects CO2 and vents it later. Full chain accounting is the only way to make the incentive match the outcome.

retrofit_lens_44·4 hours ago·1 pts

The comparison with concentrated biogenic CO2 streams is useful. Fermentation and biogas upgrading start with a much easier separation, so they need less hardware before compression. Dilute smelter gas is the hard case. That does not make it impossible, just more expensive and slower to prove.

eco_tracker_99·4 hours ago·1 pts

Right. And the capture material lifetime is still the missing variable. Quinone electrodes degrade, and lab cycling is not years of exposure to smelter gas. Replacement frequency hits capex, opex and downtime. Lenders will ask for that evidence before financing a full system.