2/21/2008

By DUANE SCHRAG

Salina Journal

A bioreactor that would grow algae from the carbon dioxide created by the proposed coal plants in Holcomb would cover more than 35,000 acres and cost more than $16 billion, according to a scientist who read an article on the subject in Sunday's Salina Journal.

Krassen Dimitrov, whose science background includes research into optimizing biofuels, analyzed the results of a pilot project completed by GreenFuel Technologies last summer in Red Hawk, Ariz. Go to www.nanostring.net/Algae/CaseStudy.pdf to read his report.

Sunflower Electric wants to build two, 700 megawatt, coal-fired plants at Holcomb. The Kansas Department of Health and Environment in October denied a permit for the project, citing carbon dioxide emissions and its contribution to global warming.

The plant would emit about 2.8 million pounds of carbon dioxide every hour. But Sunflower said almost half of that carbon dioxide would be captured and used to grow algae, which in turn would be converted to ethanol, biodiesel or food products for feedlots.

Sunflower has declined to say just how large such a bioreactor would be.

The utility owns 10,000 acres at the proposed plant site and has suggested the bioreactor might cover 3,000 acres. The Journal asked Sunflower for a response to Dimitrov's analysis.

"I don't feel inclined to ask our folks to take their valuable time to analysis this person's comments," Sunflower spokesman Steve Miller wrote in an e-mail. "If and when we are able to get a permit, and when we are able to move further down the road on the bioenergy project, I will be happy to put you in touch with the professionals who are working on this project."

A follow-up e-mail asking again for Sunflower's estimate of the reactor's size and cost did not get a reply.

According to Sunflower's Web site, GreenFuel Technologies has been hired to help design the algae reactor.

Using published results from the Red Hawk project, the Salina Journal estimated that a bioreactor would have to cover nearly 17,000 acres to capture 40 percent of the proposed coal plant's carbon dioxide emissions.

But Dimitrov noted in an e-mail that the Red Hawk project was carried out in Arizona in July; a bioreactor in Holcomb would not operate as efficiently.

His conclusion: Algal photobioreactors cannot capture more than 730 pounds of carbon dioxide a acre each day. By his estimate, a bioreactor at Holcomb would have to cover at least 35,350 acres and cost $16.5 billion -- more than four times the cost of the coal plant itself.

"Fundamental thermodynamic constraints make it impossible for such an approach to be commercially viable for fuel prices below $800 a barrel, even if flawless technological implementation is assumed," Dimitrov writes in his study.

Legislators who support the proposed coal plant have occasionally cited algae production in Israel as proof that the technology is viable. But according to Ami Ben-Amotz, the founder and chief engineer at the plant, algae yields there have averaged 20g a square meter a day -- only one-fifth the yield in the Red Hawk project.

Furthermore, the maximum theoretical yield with that process is only 25g a day, according to information provided by Ben-Amotz.

Using that technology, ponds to capture the carbon dioxide from the proposed Holcomb plant would cover more than 60,000 acres.

n Reporter Duane Schrag can be reached at 822-1422 or by e-mail at dschrag@salina.com.

---

Discuss This Story:

---