Turning CO2 to rock

Before and after: porous basalt (left) and basalt with mineralised CO2 within its pores (Source: BBC)

 I wrote a piece about this 5 years ago, when it was all still being tested.  And now it's up and running.   Of course, 4000 tonnes a year is very little.  Australia emits 16.8 tonnes a year per person.  So this project removes the annual emissions of about 240 Ozzies―but our total population is ±25 million.   It would be far more cost-effective to cut our emissions by replacing our coal power stations with renewables and our petrol/diesel car and lorry fleet with EVs.    

However, it's instructive to consider the economics of the project.  Iceland is part of the EU emissions trading scheme.  Currently, the price of carbon in the EU is Euro62, which is about US$73.   This article gives the cost of the CarbFix process per tonne of CO2 as US$30.  And because this involves negative emissions, the company would receive the carbon price instead of paying for it.  Or, to put it differently, they would be able to sell the permits created by their negative emissions to companies needing  permits for their positive emissions.  In other words, it would be economical to scale it up to compensate for the 35 billion tonnes of CO2 emitted each year globally.   But, and this is crucial, if we had a carbon price globally, then emissions would plunge, and the negative emissions required to stabilise the world's temperature would be much less as well as being profitable.

Will we get a global carbon price?  The odds are improving.  The EU intends to add a carbon tax to imports from countries which don't have one.  So a price on carbon is likely to become the norm, around the world.  It's becoming clearer and clearer to me that we will only be able to prevent a 2 degrees rise in temperature if we get a carbon tax.

Most CCS (carbon capture and storage) projects are nonsensical.  They would add something like $50 per MWh to the cost of electricity generated by coal, which is already struggling to stay competitive with renewables.  New-build coal is already 2-3 times as expensive as new-build wind and solar; worse, existing, fully depreciated and paid-off coal power stations produce electricity at the same or higher cost than electricity from new-build wind and solar.  CCS would just make coal even more uneconomic.  Yet we may, by 2030, need the kind of CCS developed by CarbFix to "unwind" some of the emissions we will make over the next decades.  And a carbon price would make that feasible.

See also Negative Emissions

From The Guardian

The world’s largest plant designed to suck carbon dioxide out of the air and turn it into rock has started running, the companies behind the project said on Wednesday.

The plant, named Orca after the Icelandic word “orka” meaning “energy”, consists of four units, each made up of two metal boxes that look like shipping containers.

Constructed by Switzerland’s Climeworks and Iceland’s Carbfix, when operating at capacity the plant will draw 4,000 tonnes of carbon dioxide out of the air every year, according to the companies.

According to the US Environmental Protection Agency, that equates to the emissions from about 870 cars. The plant cost between US$10 and 15m to build, Bloomberg reported.

To collect the carbon dioxide, the plant uses fans to draw air into a collector, which has a filter material inside.

Once the filter material is filled with CO2, the collector is closed and the temperature is raised to release the CO2 from the material, after which the highly concentrated gas can be collected.

The CO2 is then mixed with the water before being injected at a depth of 1,000 metres into the nearby basalt rock where it is mineralised.

Proponents of so-called carbon capture and storage believe these technologies can become a major tool in the fight against climate change.

Critics however argue that the technology is still prohibitively expensive and might take decades to operate at scale.