Turning carbon dioxide into stone

Scientific American - Iceland powerplant

An Iceland power plant is turning carbon emissions into stone (phys.org) - June 9, 2016.   Recent studies have found that carbon dioxide injected with water into basalt rock formations turns to stone much more quickly than previously thought.  The minerals in the basalt react with the carbon dioxide in the water to form calcium carbonate and other rocks.  The process was over 90% efficient over a 2 year period.  This surprised scientists as they expected the process to take much longer.

Turning the carbon dioxide into limestone reduces the problems with injecting the carbon dioxide into structures that just capture the gas.  There have been concern over the rapid release of this gas into the atmosphere if there are leaks in the structure.

Downsides: The process resquires heavy use of water and injection the solution is not cheap. Some microbes may produce methane gas as an unintended bi-product of the process.  Seafloor injection of carbon dioxide into basalt or other rock formations may work better.  This eliminates the need for fresh water.  As basalt makes up over 10% of the earth's crust, this may be a process that could work at many locations.

Other research has focused on using the carbon dioxide to speed up the efficiency of algal production of fuel.  Other engineering firms are exploring the use of carbon dioxide for building carbon fiber autobody parts.

Turning carbon dioxide into stone - 11 min. 

MIT grad student studies ophiolite rock structures in Oman, Jordan to understand natural carbon capture.  - 7 min. - 2009