I’m skeptical about the viability of growing algae to produce fuel. It does not seem there’s a lot of biofuel to be gleaned by the process, and the process is far from economically viable. In the end, there’s the thorny problem of separating the oil from the algae, meaning primarily that there’s a lot of water to remove, and that takes energy and/or chemicals to extract the hydrocarbons from the algae cells. This process is something to develop carefully in the laboratory before getting into any sort of demonstration projects.

Nevertheless, the process is getting a lot of press, and research funding, of late; and a lot of demonstration projects are going up. Most of what we see written is very upbeat, reflective of the positive aspects of the idea. For example, algae2oil writes in one posting:

University labs and start-up companies across the country are getting involved. Over the summer, the first mega-corporation joined in, when ExxonMobil said it would sink 600 million dollars into algae research in a partnership with a California biotechnology company.

If the research pans out, scientists say they will eventually find a cost-effective way to convert lipids from algae ponds into fuel, then pump it into cars, trucks and jets.

One article, published last July at e360 gets into challenges of the process, one stemming from using genetically modified algae, saying one rsearch group

shunned genetically engineered algae, though they almost certainly could boost growth and oil content. “We are not interested because eventually on a massive operation like this, some of it is going to get loose in the river,” says Willet [a finance director of a group funding the research]. “And I have enough regulations.”

In addition, the e360 article gets into a major technological logjam of the process:

But there’s one big problem, Ruan [a U. of Minnesota professor] says, and it’s common to any attempt to convert algae to fuel. “We have done a lot of work to get the oil out, but we know it is expensive,” says Ruan, who is lead scientist on several other promising algae biofuel projects that do not use wastewater as a feedstock.

Two methods are in common use: Drying and crushing the algae, or removing oil with a solvent. Both, says Ruan, are expensive. Researchers are exploring various ways to break down algae cell walls — through osmotic shock or ultrasound, for example — to make oil recovery easier.

It pays to keep trying, because with available processes, Ruan says, algae-diesel might cost $20 a gallon. But, says Willet, “that doesn’t take into account the avoided costs that I will realize.”

I’d like to see the basis of that $20 a gallon figure.