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Solar Tar Stills

Solar powered destructive distillation
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Not long ago I saw an article implying that there's enough vegetation/biomass generated inside the US each year to fully supply the nation's energy needs. If true, and if it was actually used, then the US would essentially drop out of the equation that contributes to global warming (since the vegetation comes into existence by taking carbon dioxide out of the air, and when burned NO MORE THAN THAT goes back into the air).

However, all that biomass first has to be converted into a form (or forms) that is more compatible with various powered equipment. So here's a notion that might work....

It only takes a few hundred degrees of temperature (Fahrenheit) to break vegetation/biomass down, in a process known as "destructive distillation". WITHOUT BURNING IT, the heat simply separates any volatile chemicals from any solids (mostly carbon but also a small amount of minerals; if burned the minerals become ash).

The volatiles are similar in composition to both "coal tar" and petroleum, and can be processed to obtain various fuels, including gasoline, of course, very much like the way those others are currently processed.

The few hundred degrees of heat can easily be obtained by concentrating sunlight. And since not so much heat is needed as to directly generate power from the concentrated sunlight, such "solar distilleries" can be built all over the country -- we would plan on matching their construction to the availability of vegetation/biomass, of course.

The carbon/mineral product can be compressed very much like the way charcoal briquettes are made, and can be burned where ever coal or coke is burned (more quantity of briquettes will be required since they are less dense than coal or coke, but in general it can be made to work. After all, the source of the vegetation biomass can be closer to a coal-burning power plant than the coal it uses now, so any expense associated with hauling more briquettes is balanced by hauling it less distance. (I know that's not always true, the biggest exception I know is found in the "four corners" region, which is rich in coal and low on vegetation-- but it can often be true.)

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Added July 19, 2008
I forgot to mention that the transports which carry briquettes to the power plant would have to carry the ash back to the places where the biomass was gathered. Those minerals, after all, were part of all that biomass for a reason. To keep from depleting the soil, the minerals must be returned.

Vernon, Jul 18 2008

Changing World Technologies http://www.changingworldtech.com/
"Anything into oil" is exactly what these guys do. I don't know why we don't hear more about them. [phoenix, Jul 18 2008]

Anything Into Oil http://www.mindfull...-Into-Oil1may03.htm
"We will be able to make oil for $8 to $12 a barrel,"...eventually. [phoenix, Jul 18 2008]

About destructive distillation http://en.wikipedia...uctive_distillation
In case you didn't see a demonstration in high school. [Vernon, Jul 18 2008]

About the "four corners" region of the US http://en.wikipedia...ers_(United_States)
For non-American readers; the coal mine and power plant are also mentioned. As implied in the main text, the American Southwest is not rich in vegetation. [Vernon, Jul 18 2008]

Home Charcoal Distiller Home_20Solar_20Charcoal_20Distiller
Make your own! [bungston, Jul 18 2008]

The famous solar-chemical reactor in Odeillo, France http://www.sollab.eu/images/promes-1.jpg
Many thousands of suns [django, Sep 18 2008]

The solar furnace in Mont-Louis http://www.promes.c...mages/montlouis.jpg
In the Pyrénées [django, Sep 18 2008]

Solar powered aluminium smelter http://www.kottke.o...s/solar-furnace.jpg
In Uzbekistan! [django, Sep 18 2008]

Better pic of the Mont-Louis furnace http://www.ecosourc...aire_Mont-Louis.jpg
Humongous!! [django, Sep 19 2008]

[link]






       And for cloudy days, you could use oil-fired burners.
No, wait...
coprocephalous, Jul 18 2008
  

       So what are the end products other than the briquets? This sounds suspiciously simple. Wouldn't this release methane or are you retarding biological growth? Do the remnants press together into a usable briquet without a binder?   

       They just opened a big gassification plant in Canada, is this the same thing?
MisterQED, Jul 18 2008
  

       [MisterQED], destructive distillation yields solids, liquids and gases, the latter two I lumped together in the main text as "volatiles". There is a huge mixture of chemicals among the volatiles, and they need to be separated. Some will be the same as chemicals found in petroleum. Some will be the same as chemicals found in coal tar (which is obtained basically by doing destructive distillation to coal; the solid product in that case is the coke used in steelmaking).   

       The gassification you mentioned is a process for combining coal with other substances (like water) to make gases such as carbon monoxide (which is a useful fuel) and hydrogen.   

       The most likely problem here is "economy of scale". There ISN'T any when talking about lots of small solar tar stills.   

       [phoenix], I'm hoping this Idea can reduce cost by using solar power, instead of burning much of the fuel, to do the distillation.
Vernon, Jul 18 2008
  

       Thanks [pheonix] was looking to post the same link.   

       I don't see this as the oil field of the future. I don't think the creation of oil supply, from this arrangement, is more beneficial than the very efficient elimination of waste. Successfully processing waste from this process, and feeding that fuel back into the process, would be like getting x oil barrels, or x coal tonnes, free.   

       A supreme form of carbon sequestration, if you like. The waste fuels the waste elimination process. That's the future of this idea. The shortfall in energy provided by the sun. [+] if you eliminate the "will produce oil for nothing part"   

       [UB] once descibed a process he put in place to render fat at an abbatior into a fuel form. The goal was not to produce excess fuel, but to mitigate fuel use/costs, from the waste. This idea would be similar.
4whom, Jul 18 2008
  

       [4whom], where does it say in the main text "will produce oil for nothing" ?
Vernon, Jul 18 2008
  

       Sorry for the flippancy, was merely trying to point out the beauty of this idea is not an "oil field" approach, but rather that the fuel generated by the idea gets fed back into the system. Every external barrel, ton of coal, not used by the process is essentially one more for some other process. Additionally there are no delivery/transmission costs, no other carbon costs. Just fuel saving!   

       The remark was not aimed at the idea, or author, but to those reading it, and possibly sceptical.
4whom, Jul 18 2008
  

       BUNGCO is thrilled that a halfbaked thought leader like Vernon wants to scale up the Solar Charcoal Distiller (linked!) and by doing so, save the world. Our factories are ready to scale up production and we can even rent you some excellent properties near the Great Salt Lake which are possessed of copious sunshine.
bungston, Jul 18 2008
  

       [bungston], sorry, hadn't heard about your Idea before. Besides, charcoal is made by destructively distilling wood, usually big chunks, and I'm talking about doing that to lots more stuff than big chunks of wood, such as mowed grass, fallen leaves, hedge clippings, agricultural waste, pruned branches, sawdust (such as isn't already used to make particleboard), and so on.
Vernon, Jul 18 2008
  

       Hmmmm .... well, if it's biomass, what about anaerobic bacteriological digestion to produce methane ? The methane is a good fuel; vehicles can run on LNG, or it can be oxidised to methanol if you need a liquid fuel. Soalr heat wouldn't be needed, as the fermentation is exothermic - just lag the vessel well, or make it very big. It's a wet rather than a dry process, but it's simple and quite efficient; no high temperature high pressure plant needed.   

       The left over "waste" can be ploughed back in to enrich the soil.   

       [+] for trying to save your funny little planet, however futile the attempt may be.
8th of 7, Jul 18 2008
  

       (ruminating)   

       Biogas is harvested from conventional landfills. I am not sure that these are set up to optimally poduce biogas. In my solar charcoal idea I set out the idea that old landfills might already contain coal.   

       I am entertaining an experiment to this end. Another good one for a high school or college project: a sure award winner in the green / Gore era. Collect biomass (eg: lawn clippings - should be available on campus or neighborhood). Bury, with plastic liner to exclude oxygen. Collect gas produced. This would require a tank of some sorts. Burn gas and quantify energy produced. After gas production falls off, exhume clippings. Characterize. Dry. Burn and quantify energy produced. Or better: add exhumed / charcoalized clippings to soil as "biochar" in test plot, and compare grass produced to a plot not so treated, or treated only with clippings.
bungston, Jul 18 2008
  

       [Bungston] what you are suggesting is basically solar-chemical processing, an old field of research.   

       See the huge solar furnaces used to flash-pyrolyse biomass and coal into liquids.   

       The Frenchies are big in this (google: four solaire, odeillo) , but I think the NREL also has a solar-chemical reactor.
django, Sep 18 2008
  

       The biogas from landfills is created by bacteria that anerobically digest that waste. It's not the same as the gas produced by charcoalization / pyrolysis.   

       I'm not precicely certain what's left by the bacteria after they've digested what they can, but I doubt it includes coal.
goldbb, Mar 19 2009
  
      
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