Solar Parabolic Trough Charcoal Oven

[SolarFreak]

I was searching solar reflective materials today.

 

I ran into this.

at 5pm their parabolic reflector produced 637 degs

http://www.altenergyhobbystore.com/solareflex_info.htm

 

Im thinking about buying some to test it out when I build up my parabolic trough. says its better than mirrors :moon:

[Michaelangelica]

I was searching solar reflective materials today.

 

I ran into this.

at 5pm their parabolic reflector produced 637 degs

http://www.altenergyhobbystore.com/solareflex_info.htm

 

Im thinking about buying some to test it out when I build up my parabolic trough. says its better than mirrors :moon:

 

Very interesting, thanks.

I could use it to lighten dark areas in my backyard.

How Much $?

[SolarFreak]

Very interesting, thanks.

I could use it to lighten dark areas in my backyard.

How Much $?

I sent an email too them for the price once I get it I will let you know

[SolarFreak]

I sent an email too them for the price once I get it I will let you know

 

 

well no answer from them. but more seaching turns up

 

ClearDome Solar

 

http://www.cleardomesolar.com/

 

and they sell it thru amazon.com

http://s1.amazon.com/exec/varzea/ts/exchange-glance/Y01Y3657020Y0054521/104-2477602-1247154

 

looks like $18 for a 2' X 4' sheet

 

http://home.att.net/~cleardomesolar/solarflex.html

[redgreenblue]

This could be an interesting precedent...

 

"Hydrogen from biomass - state of the art and research challenges"

ieahia.org/pdfs/hydrogen_biomass.pdf

(page 11)

 

Direct Solar Gasification

In 1976, Antal et al. (USA) examined the feasibility of using solar process heat for the gasification of organic solid wastes and the production of hydrogen. With a credit for the wastes used, the economic projections were thought to be surprisingly favorable. Epstein and Spiewak (1994) (Israel, Germany) give a detailed review, with many references, of the technology for solar gasification of carbonaceous materials to produce a syngasquality intermediate for production of hydrogen and other fuels. Shahbazov and Usubov (1996) (Azerbaijan) show good hydrogen yields from agricultural wastes using a parabolic mirror reflector. Thermal decomposition samples were studied by the method of derivative chromatographic analysis. In 1998, Rustamov et al., (Azerbaijan) studied the thermo-catalytic reforming of cellulose and wood pulp using concentrated solar energy. The possibility of obtaining hydrogen and carbon monoxide with temperatures of 700-750ºC on a Pt/Al2O3 catalyst is shown.

 

Midilli et al., (2000) (Turkey) present results of the use of a palladium diaphragm to achieve solar assisted hydrogen separations from the gases generated by pyrolysis of hazelnut shells at 500-700ºC. It was concluded that pure hydrogen gas could be efficiently separated at membrane temperatures between 180-250ºC. Walcher et al (1996) (Germany) mention a plan to utilize agricultural wastes in a heliothermic gasifier.

[Turtle]

This could be an interesting precedent...

Midilli et al., (2000) (Turkey) present results of the use of a palladium diaphragm to achieve solar assisted hydrogen separations from the gases generated by pyrolysis of hazelnut shells at 500-700ºC. It was concluded that pure hydrogen gas could be efficiently separated at membrane temperatures between 180-250ºC. Walcher et al (1996) (Germany) mention a plan to utilize agricultural wastes in a heliothermic gasifier.

 

You rock dude! I nominate you for the Earilest-post-with-the-most Award!:cup: I live in the virtual center of the greatest hazlenut producing area on the face of the planet. Oddly enough, I am deathly allergic to them :naughty: and so I have no qualms about pyrolyzing them.:)

The solar trough is the best design in my view for these efforts.:naughty:

[Michaelangelica]

Interesting link

http://bioenergylists.org/en/taxonomy/term/244

 

Tonight on ABC TV "Inventors" show there was a very efficient water boiling tube. Its inventor said he used a reflecting surface that trapped heat in the tube. Also a vacuum to keep the water hot.

You may be interested in looking at it.

http://www.abc.net.au/newinventors/txt/s1740164.htm

[Michaelangelica]

look at this

Friday, July 14, 2006

How To Build a Solar Generator

 

Affordable solar power using auto parts could make this electricity source far more available.

. . .

The basic design of Orosz's solar generator system is simple: a parabolic trough (taking up 15 square meters in this case) focuses light on a pipe containing motor oil. The oil circulates through a heat exchanger, turning a refrigerant into steam, which drives a turbine that, in turn, drives a generator.

Technology Review: How To Build a Solar Generator

[shimbir]

Hi all

 

I have read most of the posts of this thread with interest, and have been impressed by the ingenuity and willingness to experiment.

 

My particular interest is in the development of low technology and energy efficient ways of producing bio-char for soil fertility improvement purposes, for use in economies with large numbers of people dependent on agriculture for a livelihood e.g. much of Africa. I occasionally work with NGOs in Africa and Asia, but am not an agriculturalist (see Monitoring and Evaluation NEWS" on the web]) and would like to be able to encourage NGO interest in the uses of bio-char. FYI, I am accumulating references on bio-char (see bio-char refs in a link on my "Rick Davies on the Internet" webpage)

 

I have some questions re the experiments with solar produced charcoal

 

1. Would it not be possible to produce charcoal at low’ish temperatures by continuing the process over a number of days? While temperature will have to be built up again each day, the work done in the first day (e.g. driving off moisture), will not need to be re-done.

 

2. Would it be possible to recycle some of the gasses produced during pyrolysis (i.e. methane, I think) as fuel sources to aid heating alongside with solar energy?

 

Regards, shimbir

[Michaelangelica]

Great to see some activity on this thread

How is it all going?

 

We have had a couple of 40C days you would think could produce 3-400C by reflection.

Unfortunately I am fairly useless when it comes to handyman things. I don't own a hammer!

[Turtle]

Great to see some activity on this thread

How is it all going?

I broke up my oven and pitched it...

We have had a couple of 40C days you would think could produce 3-400C by reflection.

Unfortunately I am fairly useless when it comes to handyman things. I don't own a hammer!

 

The parabolic trough oven will work, but it's a matter of size of the reflector in regards to generating the required temperature. My 4 foot oven described here was too small to raise the temperature above 200 F.

[Ganoderma]

I am very interested in this project and intend to experiment (the sun is a nice 20-40C year round here). but can someone please explain the math to me. I am, simply, stupid when it comes to math. and what exactly does "^" mean? sorry.

 

How would one get an airtight area and allow for full heat absorbtion. Glass seems good but liek said it will get black. this makes me think of those 2 way mirrors you see in loony bins and jails. Could you use a sheet of glass with that see through mirror material? i realise the reflectivity is not great, but would it not still allow lots of heat through? or would it be like putting sunglasses on your trough?

[Turtle]

I am very interested in this project and intend to experiment (the sun is a nice 20-40C year round here). but can someone please explain the math to me. I am, simply, stupid when it comes to math. and what exactly does "^" mean? sorry.

 

The caret, ^, is read 'raise to the power of', i.e. it denotes exponentiation. For example 4^2 is read 'four raised to the second power', or 'four squared.'

 

How would one get an airtight area and allow for full heat absorbtion. Glass seems good but liek said it will get black.

Large commercial power generation stations using troughs, surround the receiver tube with a Dewar tube. I would be curious myself to know what a glass blower would charge to make them. :hihi:

... this makes me think of those 2 way mirrors you see in loony bins and jails. Could you use a sheet of glass with that see through mirror material? i realise the reflectivity is not great, but would it not still allow lots of heat through? or would it be like putting sunglasses on your trough

 

Yep; like sunglasses. :bat:

:cup: :cup:

[Michaelangelica]

Here is design!

Metta Spencer's weblog: Two New Anti-Global Warming Inventions

[silverslith]

If you can supply your waste as a slurry you could use a heat exchanger setup to process the waste by supercritical gasification. All you need is a 300bar:eek2: slurry pump.

 

It'd give you pure fertiliser out the other end and all the hydrocarbons and oxygen become gas to power your house.

 

Green Gas (SNG) Production by Supercritical Gasification of Biomass, from Energy research Centre of the Netherlands - Business White Papers, Webcasts and Case Studies - BNET.com

[Nitack]

So I know this thread may be totally dead, but I gots me some ideas...

 

First, I like the trough because it does not require adjustment, but perhaps adjustment is not needed if the design is right... Perhaps developing something that can completely encircle the target is best? maybe something a little larger like a trash can with the reflective materials surrounding it so that at what ever point the sun is at something is reflecting light. This would also present more surface area to absorb sunlight.

 

My second thought is the use of Magnifying glasses. An array of them, just as large as the surface area of what you are trying to heat, could be set up so that at what ever point the sun is at at least a few of the glasses are focusing the heat.

 

Finally, what about using the design of the solar furnace? After all, all we need to do is get it hot enough for long enough, if it were set up right that should not be a problem. A solar furnace type design could easily get above 600 degrees for an hour with no adjustment. Put it on a lazy suzan and you can track the sun manually. You could produce a garbage can amount of charcoal easily enough. Heck, even if you just set it up in the morning, and emptied it at night, throughout the day it would for a time get hot enough to do it itself...

 

Just some thoughts...

 

Also, what about a Fresnel lens? The things can melt asphalt, couldn't we get it a little less focused an heat a steel container to 600 degrees?

[freeztar]

Also, what about a Fresnel lens? The things can melt asphalt, couldn't we get it a little less focused an heat a steel container to 600 degrees?

 

When GAHD mentioned using AOL CDs, a fresnel reflector was my first thought.

 

The question becomes: Would a fresnel reflector dish at 48" produce more heat than Turtle's 48" parabolic trough?