>Algae-based technologies could provide a key tool for reducing
>greenhouse gas emissions from coal-fired power plants and other
>carbon intensive industrial processes.
Algae has a lot of potentially good applications. “Cleaning” carbon from coal-fired stations isn’t one of them. Shawn and I went over this about 4+ years ago and our basic conclusion is that while the CO2 is “double used” by using it to promote the algae grown, it still end up in the atmosphere. In short, assertions
that this approach can reduce greenhouse gas emissions are dis-ingeneous in the extreme.
>Using an intricate photosynthetic process, trendsetters have
>developed biodiesel and ethanol from an unlikely source –
>algae – that, given optimal conditions, can double its
>volume overnight. Up to 50 percent of an alga’s body weight
>is comprised of oil, whereas oil-palm trees–currently the
>largest producer of oil to make biofuels–yield just about 20
>percent of their weight in oil.
This is starting to become clear : these guys are hyping the subject for investment purposes.
Firstly : there is nothing complex about getting bio-diesel from algae. The oil is pretty much the same as most other forms of vegetable oil. You then either have to heat treat it or esterify it with an alchohol such as methanol or ethanol to get a liquid with the right kind of physical properties. The processes for doing so are quite old and well established, yet these guys are trying to slant this like it’s something new.
Secondly : you can’t get optimal growth conditions without very expensive support facilities. I’ll come back to this a little bit later. My point here is that they are, quite literally, trying too hard to “sell” the idea. As a
bio-algae advocate, I’m very suspicious of heir motivations simply because they are trying to instill an un-realistic expectation of what this can actually do.
An oil content of 25% – 35% by mass is more realistic and while this might seem like “splitting hairs” to some people, the reality of the situation is that a large scale _commercial_ process can be very sensitive in terms of it’s profitability to relatively minor shifts in the composition of it’s feed stock. Any Chemical Engineer will tell you that, and their insistence on only quoting the most optimistic values possible is fishy.
>Soy produces some 50 gallons of oil per acre per year;
>canola, 150 gallons; and palm, 650 gallons. But algae are
>expected to produce 10,000 gallons per acre per year, and
>eventually even more.
The relative numbers for algae bio-diesel production are well known. A realistic rate of about 30 times the oil
production per meter per day is accepted as a realistic value. On that basis alone I would question the values in the above paragraph and regard 3,000 gallons per acre per year as the upper limit for commercial production without enclosures ( see below for more on enclosures ).
>Algae are the fastest-growing plants in the world. But if
>it were easy to extract the fuel, most of the world’s
>biodiesel would already be made from microalgae grown on
>nonagricultural land, close to coal-fired power plants.
No : the majority of the worlds transportation vehicles use petrol, not diesel and until recently the cost of
producing bio-diesal from algae was expected to be muchhigher than production from crude oil.
>It’s critical to understand how to select the right algae
>species, create an optimal photobiological formula for
>each species, and build a cost-effective photobioreactor
>that can precisely deliver the formula to each individual
>algae cell, no matter the size of the facility, or its
Finally, we get to the point.
You can’t “select the right algae” species unless you are growing them in environmentally controlled enclosures ie, special tanks. Otherwise, local algae species will contaiminate the tank and substantially reduce the yield. Special enclosures reduce but do _not_ eliminate this problem and periodically the enclosures must be emptied and sterilised.
The problem with building such specialised enclosures is that they add considerably to the capital fabrication
cost of the facility ( and thus, to the dollar cost of the product ).