Sciencemadness Discussion Board

The energy future

franklyn - 4-8-2015 at 22:47

There are vast trackless expanses of desert which are intensely irradiated by the sun.
A promising area of research is the invention of a genetically engineered algae which
can exude a fuel , perhaps hydrogen , in covered shallow pools in these otherwise
useless regions. This is now reality in the making but yield is very low , unlike
fermentation that produces high concentration of alcohol.

http://phys.org/news/2015-02-bionic-leaf-bacteria-solar-ener...

http://www.pnas.org/content/112/8/2337

aga - 5-8-2015 at 06:04

Quote: Originally posted by franklyn  
There are vast trackless expanses of desert which are intensely irradiated by the sun.

Best make that Anhydrous algae then ...

Praxichys - 5-8-2015 at 06:31

There has been talk about long, shallow canals of water - concrete trenches - covered by a transparent roof, aerated constantly by atmospheric air or waste CO2 from nearby industry. Special, fast-growing algae is grown in these pools - essentially a giant, concentrated, nitrogenous algal bloom. The algae can be genetically modified to increase either its overall sugar content, fat content, or starch content.

The matured algae is periodically filtered from the water, dried, and either:

1. Has sugars extracted and processed into ethanol
2. Has fats extracted and is processed into biodiesel
3. Is fed whole into a fluidized bed reactor for processing into syngas and carbon powder, the former being converted to essentially crude oil by another process (Fischer-Tropsch).

The net is CO2 from the air plus H2O from the ground --sunlight--> Hydrocarbon fuels plus carbon.

The carbon powder is inert and could be stockpiled or buried as "carbon offsets" or could be sent to coal power plants.

j_sum1 - 5-8-2015 at 06:45

I have heard the same idea with algae in giant bladders that are floated on the surface of the sea. A large pilot was done. There were a very large number of unforeseen and difficult engineering hurdles to overcome and I believe that the whole thing struggled to become viable.
The idea is a good one but there is always a catch somewhere.

Personally I think that the next quantum leap in solar energy harvesting will be photochemical rather than photovoltaic. And the benchmark to beat is present plant organisms. May as well make it biological rather than merely chemical.

Of course the absolute limitation, as has already been alluded to, is that solar energy is not particularly dense and necessarily requires a reasonable land area. One could of course argue that desert regions could be utilised more productively. As a means for addressing multiple issues simultaneously, there is a lot to be said for desert reclamation and reforestation projects.

franklyn - 5-8-2015 at 10:59

The working system detailed in the opening post employs a novel concept. An engineered catalyst uses sunlight to directly split water into hydrogen and oxygen , fed to a bacterium genetically engineered to convert carbon dioxide plus hydrogen into the liquid fuel isopropanol. The hybrid process also grows and provides it's own feedstock.

http://phys.org/news/2015-04-artificial-leaf-power-molecules...

http://www.pnas.org/content/112/8/2337/F1.expansion.html


Related _
http://www.sciencemadness.org/talk/viewthread.php?tid=21979#...

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But wait , that's not all

On sight energy storage is greatly facilitated addressing the current drawback of solar energy.

http://phys.org/news/2010-03-catalyst-power-homes-bottle-hyd...

Insanus - 5-8-2015 at 13:40


I like the fact that CO2 is consumed in the process as explained in that article. In my mind, that would be one of the most desirable features of any alternative energy source.

Fermentation, while considerably cleaner than petroleum, still produces carbon dioxide as a byproduct, which is what we should be trying to eliminate. Sure, all fuels produce it when burned, but if we can consume some when making the fuel, it's a step in the right direction.

My opinion.



[Edited on 8/5/2015 by Insanus]

Awash in energy

franklyn - 19-8-2015 at 01:36

Growing pains from inadequate distribution infrastructure
http://oilprice.com/Alternative-Energy/Renewable-Energy/Germ...
I had discussed this in a series of posts with not_important here _
http://www.sciencemadness.org/talk/viewthread.php?tid=11472#...

If old reliable continues on this trend we'll be back to pre 1973 prices
http://oilprice.com/Energy/Crude-Oil/Whats-At-Stake-As-The-O...
with petroleum being cheaper there will be less demand for the dollars to buy it and it's value will drop also.

gregxy - 19-8-2015 at 09:48

There was research done on using algae in ponds back in the 80s.

(I don't have the link, but I remember it was done by the DOE)

One nice thing was that it was fairly easy to get the algae to produce oils,
which would be easier to use than hydrogen.
All they had to do was limit the available nitrogen.

There are many engineering problems. And with oil cheeper than ever due to fracking, no one would be interested today.