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Summary:

Peabody Energy, the world’s largest coal company, has taken a shine to an idea from a Silicon Valley startup to capture and recycle carbon emissions. The coal giant announced today that it has invested $15 million into 3-year-old Calera, which has developed technology to capture carbon […]

Peabody Energy, the world’s largest coal company, has taken a shine to an idea from a Silicon Valley startup to capture and recycle carbon emissions. The coal giant announced today that it has invested $15 million into 3-year-old Calera, which has developed technology to capture carbon dioxide emissions from power plants, refineries and other industrial facilities, and with the addition of waste water or brine, uses it to produce cement and other building materials.

New York Times columnist Thomas Friedman got the scoop from an unnamed source earlier this month that Peabody would soon announce a stake in Calera (venture capitalist Vinod Khosla’s “favorite baby right now”), but the companies have just publicly confirmed and revealed the amount of the investment this morning.

Khosla, whose firm Khosla Ventures has invested some $50 million in Calera, boasted in a Times piece this weekend, “With this technology, coal can be cleaner than solar and wind, because they can only be carbon-neutral.”

High-profile backers aside, the company’s claims have drawn criticism in recent months. Last spring (when the company had a diagram of its process on display at the California Academy of Sciences) Ken Caldiera, a professor in the Carnegie Institution Department of Global Ecology who studies carbon sequestration, said that from the publicly available info about Calera’s technology, it seems to go “in the wrong direction and will tend to increase and not decrease atmospheric CO2 content.”

Calera currently has a demonstration project at a natural gas-fueled power plant near Moss Landing, Calif., but like the rest of the carbon capture and sequestration sector, it has yet to be proven at commercial scale. As Google CEO Eric Schmidt put it in a talk with Department of Energy chief Steven Chu, carbon capture remains in the beta phase and still needs some “debugging.”

Emerging Energy Research noted in a recent report that it will be the six global supermajors — BP, Chevron, ConocoPhillips, ExxonMobil, Shell and Total — that will be at the front of the line to benefit from hefty carbon capture investments coming down the pike from countries that rely heavily on energy from coal. But for startups that offer a key technology for the carbon capture process itself, Lux Research analyst Mark Bunger, who heads up the firm’s Biosciences division, has told us, “there are going to be buyers.”

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  1. Peabody Energy Pours $15M Into Carbon Recycler Calera « carboneutralnow Monday, March 22, 2010

    [...] Peabody Energy Pours $15M Into Carbon Recycler Calera By carboneutralnow … boasted in a Times piece this weekend, “With this technology, coal can be cleaner than solar and wind, because they can only be carbon-neutral. … See all stories on this topic [...]

  2. Adding carbon dioxide to seawater does not precipitate calcium carbonate it dissolves it, just as carbon dioxide in rain dissolves limestone over long time scales.

    The chemistry is well known and indisputable. Carbon dioxide added to seawater reacts with carbonate ions to form bicarbonate ions which are soluble. Stated simply

    Ca++CO3– plus CO2 plus H2O goes to Ca++(HCO3-)2

    The process thus removes carbonate ions allowing more solid calcium carbonate to dissolve to reach the saturation solubility product (calcium ion concentration x carbonate ion concentration).

    Of course when you heat water containing dissolved calcium bicarbonate, as in your kettle, carbon dioxide gas is driven off and the reverse process happens. Calcium carbonate precipitates as the scale that we are all familiar with. Perhaps that is what is being observed or perhaps we are only hearing about the easy low energy part of Calera’s process.

    For Calera’s process to work as described the liquor used to absorb carbon dioxide must be much more alkaline than seawater, just like more conventional carbon capture processes. I am not an expert but I suppose it is possible that there may be a few locations where such liquids can be found underground but Calera also propose to increase the alkalinity of the water used by an electrochemical process.

    The electrolysis process Calera describe in their patent produces two moles of hydrochloric acid for every mole of carbon dioxide captured. Quoting from their website

    “Q. What products does Calera produce?

    A. The outputs from the Calera process are clean air, building materials (sand, aggregates, and/or supplementary cementitious products), fresh water, and excess carbonated water for re-injection. If the proprietary low voltage electrochemical process is required for additional alkalinity, hydrochloric acid will also be produced.

    Q. What will happen to the hydrochloric acid?

    A. The hydrochloric acid can be sold on the open market for industrial uses, used for oil well or brine production or be injected in deep geologic reservoirs”

    As the lowest pH mentioned in table 1 of their patent

    http://v3.espacenet.com/publicationDetails/originalDocument?CC=CA&NR=2666147A1&KC=A1&FT=D&date=20100202&DB=EPODOC&locale=en_gb

    is 3.115 this hydrochloric acid is likely to be be very dilute, 0.000767 moles per litre based on 3.115. The volume of acidic liquid to be disposed of is therefore 59,235 cubic metres per tonne of captured carbon dioxide.

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