what is interesting to me is that the biofuel product is crude oil, meaning we are still dependant on the refining process and at the mercy of large oil companies and their distribution systems. what is of particular interest to me is that 10 years ago i was doing carpentry work for a biochemist. in our small talk he was telling me about the new bio processes that were making diesel. he seemed very sure that they were economically feasable at that time.
This gets complicated. New processes aside, the oil extracted from algae tends to be an analogue of 'light sweet crude'* that, because it hasn't been stewing in rock for at least 100k years, is acutally light enough to burn in diesel engines without modification. That's probably what the biochemist was actually talking about. It's a bit like the home-brew types who run SVO(Straight Vegetable Oil).
However, you need to transform/refine it if you want propane, gasoline, jet fuel, proper diesel etc... The refining process changes the molecular bonds, and one of the side effects is lowering the melting/boiling temperatures - otherwise you'll need fuel heaters even more if you don't refine it.
Economically feasible, yes. Scalable, no.
If it's economically feasable, then it's scalable.
You'd need an algae farm at least as large as the refinery, if not larger.
How many cereal plants are as 'large' as the farmlands that grow the crops to feed them? I think the general concept would be that you'd have a MASSIVE algae farm located in some desert-like area(so it's not already used land) near enough to the ocean to provide the water(though it sounds like this system can come pretty close to closed-loop; but you'll still need to replace the H20 consumed to provide the hydrogen for the oil molecules). The bioreactor turning the algae into crude would merely be the most expensive per square foot assembly, but still cheap compared to the tray system needed for the algae itself. Assuming we don't start running ships to harvest directly from the ocean, of course. I figure you'd have thousands of acres of farm for every acre of reactor. Depending I might even go vertical - the trick is to provide the right amount of sun, and desert areas can actually provide too much - so go vertical, spread the sun over a larger area. I've heard that algae can be used to produce 100X as many gallons of biodiesel as you can ethanol from corn per acre.
Of course, the scale involved is enough to potentially solve our unemployment issue, or require amazing amounts of automation. Either way extremely neat tech.
*Light refers to the density, sweet refers to that it's low in sulfur. 'Crude' of course means it's unrefined.
