Wednesday, September 15, 2010

Yummy, Carbonated Light

On the topic of biofuels, solar technology developer Joule Unlimited, Inc. announced yesterday that they have been issued a U.S. patent (#7,794,969, titled "Methods and Compositions for the Recombinant Biosynthesis of n-Alkanes") covering its new energy conversion process. The process converts sunlight and waste carbon dioxide (CO2) into liquid hydrocarbons that the company claims are fungible with conventional diesel fuel. So unlike making traditional biofuels (where you turn sugar or algal or agricultural biomass into alcohol - see story below), this technique is a direct, single-step, continuous process requiring no raw material feedstocks. The company claims that this could be incredibly efficient and cost as little as $30 per barrel equivalent.

Alright. Cool. So what exactly is happening here? Well, Joule has these microorganisms (they don't say what kind) that function as biocatalysts that use only sunlight, waste CO2, and non-fresh water to produce hydrocarbons that are diesel range and chemically distinct from biodiesel. Oh, and they are compatible with the existing infrastructure. Wanna add some more good news? Apparently they are sulfur-free and ultra-clean.

Do I sound a little skeptical? Probably because I am a little skeptical. After all, this info is coming from a company press release. So I looked up the patent number to try to fill in a couple of holes in the story.

One of these holes is the microorganism they are using to convert the light and CO2 into fuel. Apparently they are using an engineered cyanobacterium that "comprises a recombinant acyl ACP reductase (AAR) enzyme and a recombinant alkanal decarboxylative monooxygenase (ADM) enzyme; and exposing said engineered cyanobacterium to light and carbon dioxide, wherein said exposure results in the conversion of said carbon dioxide by said engineered cynanobacterium into n-alkanes, wherein at least one of said n-alkanes is selected from the group consisting of n-tridecane, n-tetradecane, n-pentadecane, n-hexadecane, and n-heptadecane, and wherein the amount of said n-alkanes produced is between 0.1% and 5% dry cell weight and at least two times the amount produced by an otherwise identical cyanobacterium, cultured under identical conditions, but lacking said recombinant AAR and ADM enzymes."

Mmm-hmm, that's a lot of "said's." I would refer to the patent itself (link below) if you are interested in details like the actual amino acid sequences of said (*smile*) enzymes. Another hole is the productivity and/or efficiency of this process, and this is where I would again point you to the patent itself because it is a while lot of numbers. Although there are some figures that help to simplify the information. Based off of what I know of biofuels (which, admittedly, isn't all that much) it seems kinda impressive. That is, of course, if it works.

Another concern, or hole, they left, at least in their press release, was their plans for mass production. In my opinion, on of the problems with biofuel production is not just the efficiency (or lack of) of the process but actually scaling up the process to make an affordable product that anyone can buy anywhere. And that, I think, will be the thing to watch for with a story like this: Will we, average people, ever see this easily available to us?

Look up the patent using the U.S. Patent Number 7,794,969 at this website:

This is the press release from Joule:

This is where I originally found the story, but it says basically the same things as the press release:

(image from
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