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Researchers Discover Enzyme That Harnesses Light To Make Hydrocarbons (acs.org)
Researchers from the Biosciences and Biotechnologies Institute of the French Alternative Energies and Atomic Energy Commission have discovered a new light-driven enzyme, christened fatty acid photodecarboxylase (FAP), that uses blue light to drive the removal of carboxyl groups from fatty acids to form alkanes or alkenes. Such an enzyme could be used as fuel with no further modification. The Biological SCENE reports: FAP joins a select group of so-called photoenzymes, including DNA-repair enzymes called photolyases, that use light for catalysis on their own rather than functioning as part of a larger complex such as photosystems I or II, which are used by plants and algae for photosynthesis. FAP contains flavin adenine dinucleotide (FAD), which commonly serves as a redox cofactor in biological reactions. In the case of FAP, however, FAD absorbs blue light to reach an excited state that abstracts an electron from the carboxylate group of a C12 to C18 fatty acid, which then decarboxylates to yield an alkane or alkene. The study has been published in the journal Science. Further reading: Ars Technica
There's already an overabundance of "fap" enzymes here.
Chemist here. The loss of the carboxyl group (the COO part R-COOH, where R is a long chain saturated or unsaturated hydrocarbon depending on source) in fat or vegetable oil acids produces CO2. The resulting hydrocarbons (R-H) will have somewhere between 16 to 18 (plus or minus) carbon atoms and be may be solid or thick oily materials at room temperature, not likely suitable for vehicle fuel. Burning one molecule of a C-18 hydrocarbon will produce 18 molecules of CO2. If you want to use the acids produced from fat or vegetable oils as some kind of fuel, why not just burn the fat and save the expense in time of producing the high molecular weight hydrocarbons from them? For vehicle fuel one would need to crack these hydrocarbons and make branched chain HCs for gasoline, but that's a whole other story.
Dude, this is carbon neutral. Draw a control volume, do some chemistry and thermo... the carbon for this hydrocarbon comes from the atmosphere. Upon combustion, it goes back into the atmosphere.
As a bonus. not all hydrocarbon from this process needs to be burned. Sequester it in underground caverns or beneath the sea, like hydrate deposits, and you'll effectively be taking carbon out of the atmosphere.
This is a very interesting development with a lot of promise!
"Every time I see an adult on a bicycle, I no longer despair for the future of the human race." - H. G. Wells
Hello anonymous chemist, I would think that the more useful application for this enzyme is to convert abundant plant derived fatty acids into suitable high weight molecular precursors for plastic synthesis in a post peak-oil economy, as the costs of crude oil derived hydrocarbons becomes more and more onerous.
Coupled with some of the other inorganic catalysts used in crude refinement (to increase the fraction of lighter alkanes, and thus improve fuel oil yields from paraffin rich crude sources, such as tar sand) it might even be able to partially bolster the demand for fuel oil, but you are correct that it is more economical to just burn the fatty acid in appropriate engines. (Trans-esters of fatty acids, processed with lye and methanol, are the bread and butter of existing biodiesel fuels.)
I would think that burning the expensive enzyme (instead of the fuel it produces) is quite wasteful.....
Hmm, twice the number of electric cars at 60% of the GDP. I'm not seeing your argument ;-)
The truth may be out there, but lies are inside your head
The stuff that actually affects society is done in industry, not academia. Nevertheless the people who work in the industrial labs all graduated from university labs so the academic R&D dollars are not actually wasted.
Pray tell, what kind of university trained you as a chemist without, apparently, giving you any kind of primer on fundamental research versus applied research, and their distinctive but mutually beneficial roles in society?