Carbon Dioxide to Biofuels
Googling "carbon dioxide scrub" had some interesting results. First on the list was a blog entry from last October that was an eye-opener. Algae bioreactor scrubs CO2 from power plant smokestacks to produce biofuels. I've written about algal oil here before, once in February and once before that in an entry that's been lost somewhere in cyberspace. That entry was based on oilgae.com, a very thorough site on the production of biodiesel fuel from algal oil.
So how does this idea work? According to Greenfuel Technologies Corporation, you take flue gas, or some other gas stream rich in carbon dioxide, and introduce it into a bioreactor, a plastic tank filled with nutrient-rich media and algae. The algae use that carbon dioxide and photosynthesis to grow. Some of the media is withdrawn continuously and the algae is harvested through a drying process. The oil is then extracted from the algae and converted into biodiesel fuel. Ethanol, methane and hydrogen are also potential products from the downstream processing process.
To me, this makes more sense than pumping carbon dioxide into geologic formations as most carbon dioxide sequestration plans call for. Use the gas as we can and get a benefit from it, rather than putting it underground and crossing our fingers, hoping it stays there.
Comments (3)
I saw a TV program on TLC or Discovery about this, pretty neat idea. Kinda cool looking outfit as well.
Posted by Darren | May 9, 2007 6:05 PM
Am I missing something, or is this not at all a way to take CO2 out of the atmosphere? Capturing it in algae and then burning the oil from them instead dose NOT help lower the amount of gas making it to the atmosphere. Sure, it might be good to use the CO2, but if you accept that too much CO2 in the atmosphere is a problem (kudos for keeping the blog civil and ongoing despite swarming commenters who seem to dispute this at every opportunity, by the way, keep it up), I don't see how this helps. If I'm reading it right:
There's CO2 rich gas in a pipe (assumably from some burning of coal/gas/oil).
Algae goes in pipe and captures some CO2 (the rest would escape).
Oil from algae is then collected, which would be amde largely from the CO2 you originally captured.
This oil is then burnt, CO2 goes into air somewhere else.
I see how this can benefit local air quality, and make a power plant look good, but without "capturing" CO2 and not allowing to re-enter the short-term carbon cycle, how is this reducing CO2? I'm not trying to be a jerk here, I am genuinely curious
Posted by qweb | May 9, 2007 6:32 PM
I believe Robert Zubrin proposed this (and actually built a working model) as a method of generating rocket fuel from the Martian atmosphere. My understanding is that that a similar method was used in the 19th century and that hydrogen is necessary to catalyze carbon dioxide into a methane-type of bio-fuel.
Posted by Michael J | May 10, 2007 10:47 AM