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Filling Up On Algae
grqb writes "News.com is reporting that GreenFuel Technologies, a Cambridge, Mass. based start-up, is using algae fed with sunlight, water and emissions from power plants to make biodiesel. The benefits are that heavy polluters can cut back on their emissions and at the same time make biodiesel. The algae consumes carbon dioxide as part of photosynthesis and they also break down nitrogen oxide, reducing the amount of polluting gas released. Once the algae are grown, the conversion to biodiesel is a relatively simple process. The company uses technology licensed from a NASA project. The only barrier now is to prove that it is economically viable."
This is unAmerican and you hippies should be ashamed of yourselves! ;)
The _only_? Oh, that should be simple, the *only* thing left eh?
How many brilliant projects have failed to meet that last hurdle.
1)dont tend to your aquarium for 8 years
2)???
poor the contents of the aquarium into gas tank
4)PROFIT!
Biodiesel is much more significant than solar. With the energy density similar to normal diesel fuel, you can run a car with it, vice solar (except some very unrealistic designs). If biodiesel is able to compete with normal diesel fuel, the entire political landscape of the world will change. The industrialized countries will no longer need to help Saudi princes build palaces. The money that is being exported will instead stay in the country boosting the economy. This will fuel an unprecedented period of economic growth.
As a side benefit, it releases no net CO2 (burning - photosynthesis = 0). Just pray that the cost of oil continues to rise. At roughly $3.50 per gallon diesel, biodiesel will be more economical. Economies of scale will take over and old-diesel will be history.
Well, some varieties of algae can be pretty high in oil. Some are as high as 50% oil by weight. By crushing the algae, separating the oil, and performing transesterification (the same process used to convert soy or rape oil), you can get biodiesel from it. There has been a lot of talk in the biodiesel circles about using algae, so lets hope this group can bring it to market. BTW, people also talk about using algae in pools that capture the run off from, I believe, cattle grazing land. Not only does it clean the water, it also has a very nice byproduct.
Thermal depolymerization and this algae farming *might* be practical, but conventional crops to ethanol is a waste of time (or, at least, is not worth subsidising on environmental grounds).
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
What I have see are numbers that make the whole proposition somewhat marginal without advances in genetics of algae.
To get an idea of what you are going to get out an optimal system (using Calchemy's Unicalc):
.8gm_oil/cm^3; .6gm_prepressed_oil/gm_algae; .7gm_oil/gm_prepressed_oil?$/(acre*month)
50$/barrel_oil; 50gm_algae/(m^2*day);
= 1016.17 $/(acre*month)
Please check for any errors, but it appears that under optimal conditions, meaning a sunny desert with warm nights year round and algae production consistently at the height achieved by ASP during their 20 year study, using a species modified to produce optimal oil and a consistently high price for oil, one can get $1000 per acre per month.
We have $1000/month to make this realistic and to pay the rest of the expenses of the operation per acre.
A covering will eat into that $1000 in two ways:
1) Amortization (which has to be fast)
2) Solar flux reduction
Let's take out the solar flux from the covering first and say we lose 30% leaving us with $700 for the rest of the operation. Let's further say that we need half of that for expenses other than structure amortization, leaving us with $350. If we assume commercial lending rates of around 12% and zero amortization -- just debt service, we can afford $35,000 to cover an acre so with amortization it drops to sometning more like $10,000 to cover an acre.
Covering these ponds sounds problematic under optimal conditions, let alone constructing bioreactors -- and we haven't even gone to climates with less total solar flux.
Recalculating for volumetric production of oil:
50gm_dry_algae/(m^2*day); .8gm_oil/cm^3; .6gm_prepressed_oil/gm_dry_algae; .7gm_oil/gm_prepressed_oil?gal/(yard^2*month)
= 0.17636 gal/(yard^2*month)
What this says is that the best you can expect, under optimal species and growth conditions, of any algae-oil system that relies on the sun for its energy, is for each square yard of solar-exposed pond to produce just over a fifth of a gallon of pressed lipid oil each month -- which you must then process into biodiesel through the normal methods. If you find other energy sources you can feed to algae, you might beat this but algae are optimized to consume solar energy so you have to be very skeptical of any claims that exceed this productivity level and really find out where the energy is coming from and how the algae are metabolizing it.
Let me try to break down the parameters of the calculation:
50gm_dry_algae/(m^2*day)
This is the target productivity figure given by the National Renewable Energy Laboratory's review of the last 25 years of algae biodiesel work. It basically says for a given area, how much dry algae you should be able to get out of an _optimal_ system per day -- optimal climate, species, solar flux at pond surface, etc. If you can economically create these conditions in your "back yard" then you can get that level of productivity. Find the NREL's review at:
http://www.nrel.gov/docs/legosti/fy98/24190.pdf
.8gm_oil/cm^3;
This is the density, or specific gravity of diesel. Diesel isn't quite as dense as water. This probably should have been the density of lipid oil but I didn't have that figure handy.
.6gm_prepressed_oil/gm_dry_algae;
The _highest_ oil content, of oil-producing algae reported by the National Renewable Energy Laboratory's review, was 60%. This presumes algae grown under their high rate goal of 50gm_dry_algae/(m^2*day) but this growth rate has yet to be achieved with this high, 60% oil content (to the best of my current reading of the NREL report).
.7gm_oil/gm_prepressed_oil
This is a fairly optimistic 70% fig
Seastead this.
1 gallon of diesel = 128,000 BTU = 37.5 kilowatt hours.
Sunlight's energy content is about 1 kilowatt per square meter.
Assuming 12 hours of sunlight per day, and assuming the tube has an average cross section to the sunlight of 3 m^2, that gives us a theoretical maximum of:
12 hrs * 3 m^2 * 1 kw/m^2 = 36 kw hr per tube per day.
Or just under one gallon per tube. And that's assuming 100% efficiency. Biological processes usually have very high energy efficiencies (>80% IIRC), but some of that energy will be needed to maintain the algae's internal life functions (growth, repair, etc), so I'll use 50% as a rough estimate.
At 50%, you'll need two tubes per gallon. Standard tanker trucks carry 5000 gallons, so you'll need 10000 tubes to fill a truck per day. Assume a 2.25 m^2 footprint (to make the math easy), that's a 22500 m^2 tube farm, or an area 150 m on a side. A little more than five and a half acres, or exactly 2.25 hectares.
A legparnasom tele van angolnaval.