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Algae That Cleans Emissions and Produces Fuel
**$tarDu$t** writes "Isaac Berzin, a rocket scientist at MIT has come up with an idea for using algae to clean up power-plant exhaust. His research began 3 years ago in an experiment for growing algae on the International Space Station. His idea consists of building algae farms near power plants to provide a means to reduce CO2 and nitrous oxide emissions. Emissions are filtered through the algae. Then the CO2 saturated algae is harvested and squeezed to produce a combustible vegetable oil (biodiesel) and a dried green substance that can be further processed into ethanol."
1. Fuel -> Power Plant -> Emissions
2. Emissions -> Algea -> Fuel
3. Profit!
Yes, under the proper conditions. Stack emissions are primarily CO2, NOx and various sulfur compounds. What primarily keeps algae levels in check in the environment are various micronutrients (phosphorous, nitrogen, iron). Given that smokestack emissions should be fairly defined composition, it should be straight forward to supply the exact amounts of additional nutrients to stimulate growth without overpopulation problems. Besides, this is an engineered process, not simply dumping emissions into a river.
From reading the article, the algae suck up the CO2 and the Nitrogen Oxides from the power plant emissions. That's obviously a good thing. The algae are then used to create methanol and biodiesel. What happens when you burn the methanol and biodiesel? Doesn't that just release the stored CO2 and Nitrogen Oxides back into the atmosphere, or am I missing something here?
Also, if these algae are so great, why don't we fill up thousands of acres with them, not just 15,000, and suck the CO2 and Nitrogen Oxides out of the atmosphere, reducing greenhouse gasses. Maybe the algae could then be dumped into the deep ocean, creating a carbon sink.
Does it take less pollution to create methanol and biodiesel this way, versus drilling them from the earth?
I've been interested in biodiesel for a long time, but folks like me in New York and people in other states with California emissions cannot currently buy a new diesel passenger car. Hopefully that will soon change when the US starts switching to USLD diesel later this year (Ultra Low Sulpher Diesel) which will allow manufacturers to install emission control equipment on their new vehicles.
I'd bet that this will work more effectively if the algae/water mixture is sprayed into the power plant exhaust rather than bubbling exhaust gas. Spraying will maximize the surface area exposed to the exhaust and reduce the system's energy use. It will take much less energy to compress a small volume of algae-liquid and make small drops than it does to compress a massive volume of gas to make small bubbles.
I can even imagine a multistage sprayer. A hot-stage sprayer injects matured algae-mix into the hot exhaust gases to both cool the exhaust stream and create a desiccated algae powder (for fuel production). A cool-stage sprayer injects living alga mix into the cooled water-saturated exhaust stream. Even with the two stage process I'd bet that the "cool" stage will still run at a relatively high temperature. Perhaps the engineers will need to adapt a thermophilic algae (such as live in hot-springs) to make the system feasible.
Two wrongs don't make a right, but three lefts do.
"I wish I had a nickel for every "So and so scientist at so-and-so university has come up with such-and-such alternative to gasoline" story I've seen over the last 30 years."
Wish I had a penny for every knee-jerk post made by someone who didn't even bother reading TFS, let alon TFA.
This isn't about alternative energy supply (mostly). This is about waste mediation, particularly CO2. The generation of usable fuels by the algae is just a nice little benefit, kind of like using an afterburner to generate extra power while reducing particulate emissions.
"Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
I don't know the details, but Dr. Ray Crist at the college I went to worked on getting algea to clean up heavy metals since like the 70's until he passed away last year at the age of 105. Hopefully more people will work on this type of stuff... I don't think it takes a rocket scientist... though it probably helps that Dr. Crist was the director of the Manhattan Project for a time.
Actually, WI is upping their ethanol blend again, we have a 200mil gal/year soy plant going in just out side of madison, and the new Milwaukee power plant could wind up being one of the most advanced clean coal burning plants in the US.
The big problem is not solutions, but cost. $3/gallon is the magic point for gas. Unless vehicles shoot way above 30mpg and gas prices don't increase past $3/gal alternative fuels will be cheaper. And the joy of capitalism is that the most financial sound path is the best funded. So yeah, hydrogen fuel cells have been possible for decades. But why would anyone invest in hydrogen when it costs the equivilant of $3/gal of gas today when gas has always been cheaper? If hydrogen costs 15 cents per mile, and gas costs 10 cents per mile, gas is going to get the investment. But when gas costs 13 cents a mile, and is only going to rise, people start looking into hydrogen.
That's where we're at now, gas is still cheaper, but just barily. As the hydrogen and alt fuel networks expand, and the cost of gas increases, alt fuels will become more and more popular.
-Rick
"Most people in the U.S. wouldn't know they live in a tyrannical state if it walked up and grabbed their junk." - MyFirs
You are kind'a correct. True, algae grows everywhere. The problem is that it is not growing in a concentration for anything usefull. If you dip your fish in an algae broth that is as concentrated as necessary for it to be of any use for extracting food supplements they will die in 5 minutes or less because their gills will be completely clogged up. I assume that biofuel is the same (I may be wrong). And by the way - I used to study this (granted this was 20 years ago) and I used to have 8+ fish tanks around the apartment. So I know both sides of the story first hand.
Baker's Law: Misery no longer loves company. Nowadays it insists on it
http://www.sigsegv.cx/
'Just go Nuclear OK'
This scientist considers the problem a bit more carefully.
World Power consumption tallies 12 TW annually.
Recoverable Uranium deposits tally 3.4-17 million metric
tons with a total energy content of from 60-300 TW.
So after 6-30 years and all of the U is used up the world
will be left with the same quandary it had before (assuming
that WMD proliferation and/or an acute waste problem have
not forced the issue sooner).
Nature (2002) v 298 p 981
The trouble with coal is it is very cheap.
The trouble with 'just' type answers is that somebody
has probably not done their arithmetic.
537
octave:1> kw_per_gram=1000 kw_per_gram = 1000
octave:2> kw_per_metric_ton=kw_per_gram * 1000000
kw_per_metric_ton = 1000000000
octave:3> 3.4 * kw_per_metric_ton
ans = 3400000000
So this agrees with your calculation. But we aren't at this point "right back where we were before", because the "waste" is actually a fuel (which France's and Japan's breeder reactors make use of, and "actually produces more fuel than it consumes"). There are also thorium breeder reactors, with "thorium reserves estimated to be 5-6 times the known availability of uranium sources"
So 6 to 30 years becomes an estimate that ignores the energy content of the fuel produced, and also ignores thorium reserves. In fact, "recoverable" is based on current market prices. If you allow for the inevitable doubling of the market price, Bottomline: there is a lot more to nuclear power than the numbers you sketched out.
Actually, this is old news to me since I was part of a senior design team researching possible methods for CO2 handling for a fuel refinery in this state. My project was in the Fall of 2000. We found the most promising algae projects were already underway at the University of Hawaii (http://www.catalog.hawaii.edu/academic-units/ctah r/plant-biotech.htm) but the point was not lost on us that converting CO2 into fuel didn't actually remove it chemically in the end. Burn the fuel later and you have CO2 again.
Our proposal actually involved using the 99.95% chemically pure CO2 to enrich the atmosphere at a hypothetical hydroponic greenhouse complexe offsite but nearby the refinery while using low-energy waste heat to keep them temperature-controlled all year. Unfortunately, as the parent points out, large amounts of light are needed to encourage growth and Washington does not live at a light-intensive lattitude (especially the western half of the state which is famous for rain).
The difficulty is that this is more of an environmentalist's idea of poetic irony rather than function: fuel plants that make environmentally-friendly and robust crops as well. Image-wise, how do you convince people that crops grown right across from an oil refinery are healthy? Good luck. We can't even convince people that nuclear power is clean in this state (Hanford, anyone?).
Other industry proposals involve sequestering the gas at extreme oceanic depths or in spent wells where they currently pump brine anyway. It is good to know they are looking into it but "they" have been for awhile and I keep hearing about researchers doing the looking and no plants doing any building...