Carbon capture concepts are the vice presidential nominees of green tech. None are perfect.

Large oil companies and several university researchers advocate compressing carbon dioxide and shuttling it underground. BP, for instance, wants to exploit captured CO2 — produced as a byproduct at a futuristic hydrogen-manufacturing facility — for enhanced oil recovery before permanently shoving it in rock formations. Dissolving CO2 in underground saline aquifers and porous rock also ameliorates the odds of accidental release.

"There is a good reason CO2 is the end product of combustion. It is a low energy molecule," Steve Koonin, BP’s chief scientist, said earlier this year. "Getting rid of CO2 by burying it underground may be the best option."

Nonetheless, undergroundstorage— and the image of towns suffocated by sudden, catastrophic releases – is a tough sell at community planning boards.

Startups like GreenFuel Technologies and SequesCO want to turn carbon dioxide into, respectively, food for algae (which can be crushed into biofuel) andsynthetic petroleum. The problem? No one has uncorked how to do this yet on a big scale. You can put ocean sequestration (Climos) and CO2-capturing membrane fences in the same category (see Funding Roundup: SunEdison Snags $161M, Climos Seeks $10M to $12M to Fertilize Ocean).

In that light, mineralization—converting waste gases into industrial powders— is the faceless, unknown governor from a Great Lakes state. It’s attractive because it isn’t the other guys.

Derek McLeish, CEO of Carbon Sciences – which has a system for converting CO2 into calcium carbonate (CaCO3) – rolls off the benefits. Calcium carbonate is a $12 billion-a-year business and growing. Although some calcium carbonates can sell for $1,000 a ton, 80 percent of it gets bought by the paper industry, which started substituting it for wood chips in the 1980s.

“The paper guys pay $200 to $250 a ton,” he said. CS also plans to garner revenue by selling carbon credits as well. “The supply side? Everyone wants to give you CO2.”

Converting gases into a solid requires energy and money, but the energy usage and cost are offset because the calcium carbonate won’t have to be mined from the ground, he argues. (The calcium feedstock will come from mine tailings.)

McLeish claims that CS will be able to deliver carbonates at 30 to 40 percent less than what the paper industry pays now, and every ton of carbonate will capture a net 440 kilograms of CO2. The company is working with Abo University in Finland, where underground storage won’t work.  

Skyonic, out of Austin, Texas, has a similar system, but it converts carbon dioxide into baking soda, or sodium bicarbonate. It currently has a test program with the giant utility Luminant. Skyonic’s baking soda is cleaner than the baking soda you buy at the store, Skyonic founder Joe Jones noted, but don’t expect sellers to advertise that all that home-baked goodness comes from a smokestack (see CNET story).

And even if it can’t be used commercially, the output won’t swamp us in power. Finland’s annual output of CO2, converted into carbonates, would occupy two soccer fields eight meters deep, McLeish said. One ton of CO2 becomes 3.5 tons of carbonate. With sodium bicarbonate, you get a ratio of1 ton of CO2 to 1.9 tons of baking soda. And bicarbonate is inert, Jones said.

Granted, if a vinegar truck crashes into a silo of it, you’d have a massive science fair volcano, but that’s about it.

Thus, with mineralization, you get rid of persistent storage, the flaw of classic sequestration. The majority of the gases also get reincarnated in an economically attractive way. And, unlike CO2 fuel conversions, it won’t take Nobel-class breakthroughs. Making money from garbage, in a way that won’t require too many PhDs and that will pacify the neighbors? This is American as the iced-coffee smoothie.

And I don’t know why, but mineralization backers also are a lot lower on the pretension scale than your average Harvard MBA exec touting an algae plan. In his spare time, McLeish races cars at the Bonneville Salt Flats. Jones says he got the idea for the company while watching the Discovery Channel with his kids.

The catch? These ideas aren’t completely baked either, although the horizon doesn’t seem far off. CS hopes to have an industrial-size prototype ready in 18 to 24 months and is seeking funds. For now, McLeish is demonstrating the process with a mobile unit he totes around in a white utility van. The CO2 comes from the tail pipes (see the video here).

The carbonate market can be tricky too — an early plan to sell the byproducts to the wallboard industry doesn’t look as promising as it did last year, McLeish said. Some VCs who’ve looked at Skyonic worry about the energy/cost balance.

You can’t have everything.

The views in this opinion piece are not connected with Greentech Media News.