Saturday, November 10, 2007

A Less Dorky Geo-Engineering Project

Harvard's Kurt Zenz House is interested in "all things energy", especially carbon sequestration technologies. In fact he has been involved in several deep sea carbon storage schemes like those I have written about here.

More recently, Mr. House has been in the news for his work on "electrochemical weathering", which aims to increase the ability of Earth's oceans to store CO2 by rendering it less acidic:

Weak acids in water normally dissolve rocks on land over time, forming an alkaline solution that runs into rivers and then the sea. Electrochemical weathering creates a stronger acid to drive much faster reactions. Still at a theoretical stage, the method involves passing an electric current through seawater to separate out chlorine and hydrogen gas, similar to the industrial chloralkali process used to make chlorine gas. The chlorine and hydrogen are then combined in fuel cells to form strong hydrochloric acid. The fuel cells would be housed in an industrial-scale plant that would collect and use the acid to dissolve silicate rocks, which are common worldwide. This would neutralize the acid and the resulting alkaline solution could then be returned to the sea. Overall, the process would help stabilize the oceans' pH, House says, and could benefit corals which are dying from ocean acidification caused by rising CO2 levels.

House imagines a building a series of coastal processing plants equivalent in capacity to about 100 large sewage treatment plants, and running them on geo-thermal power (rather than, lets say, coal) so the CO2 pumped into the air in act of plant operations does not overwhelm the amount sequestered by the electrochemical process. For profit, plants could sell carbon reduction credits in a cap-and-trade scheme, and could conceivably store 1 gigaton of CO2 annually.


"Around the plant you would get a very basic solution," which could contain chlorinated byproducts, House says. These byproducts could harm sea life locally.

Furthermore, the scheme would probably be too expensive to be practical unless there already existed a cheap source of renewable energy on which to run the plants.

Nevertheless, way more doable than shooting a thousand-mile-wide mirror into outer space.


Anonymous said...

he's looking for investors . . why don't you pony up some of your hard earned sheckles ??



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