[Stoves] Plastic in briquettes, and potential new stove brick design. (declassified ? )

Sat Jul 12 16:57:41 CDT 2014

Paul, 

Thanks for the info about the use of PET plastics in briquettes and Kens and Robert briquette bricks 

We had an interesting discussion about four/ five  years ago in this group about the use of plastics in briquettes: Kevin Chisolm and others had reported on the issue of combusting at least,  polyethylene as a short chained hydrocarbon. Studies  from Scame out o the UK and Sweden, concerning the wiso dom of burning it instead of burying it. 

Turns out that this type of plastic is relatively "clean burning" and it  turns out to also be the main constituent in those ubiquitous whispy two to  five (??) liter sized shopping bags. These bags comprise the majority of the very  blight we see in all too many depressed economies globally. (They are sarcastically termed the national flower of many developing nations).  

As applied to   low pressure,  wet process of biomass briquetting, about one typical bag (weighing 6 to 8 grams (size wise it would hold  two to three liters ) is abou all that can be used  per one 130 gram briquette ( 10cm Ø x 7cm height   before one begins to  encounter binding issues and drying problems.  Thats  fine though,  because  two and a half of such briquettes are required per the avdrage family member per day  while the average family of 6 such average persons only consumes about two to  four bags per day. Using them in briquettes would actually tend to clean up the neighborhood "for free". 

In using the bags  however , one needs to really shred them into whispy shards ( with a mean Ø of ≤12mm (½") --with torn edges of stringy ganglia-like fibers. 

Anything more solid much less larger or in the case of chopped pet bottles more resistant to deformation, and they will tend to seariously block the migration of moisure out of the briquette in the drying process.  I think taht in the case of utilising the PET bottle in said briquetting process at least, it would require chopping grinding  them into ≤ 2.5mm (⅛') Ø granules --- much like  the feedstock for plastic injection machines---and using them as a granular additive much like rice husks sawdust etc etc..before they could be found useful at least in the low pressure wet process. I can only speculate that if used in higher pressure briquetting operations, they may well melt and flow interstitally, thus acting as a very durable binder… 

I will be interested to read the study when you / Robert gain access to it.

Re the adjustable briquettes for stove wall design, I would ask Rok Oblak to please comment on his earier design out of Malawi as well as Brian and Nancy Davis to comment on the evolution fo same for their COCI Nica stove as it is emerging rapidly in  Nicaragua.

 Thanks again, 

Richard Stanley
----------

On Jul 11, 2014, at 8:18 AM, Paul Anderson wrote:

Stovers and briquette folks,

I thank my infrequent correspondent Robert Haston for an exceptionally informative message that he allows me to share with all of you.   

Biggest news (to me) is about the study of the inclusion of plastics (including PET water bottles) into biomass fuel briquettes!!   Link is given to a scientific study done in Greece.   I hope our briquette and emissions gurus will be making comments.

I ask Robert to please help find out from his Greek contacts about the testing of these briquettes in OTHER stoves.   I hope that will     include the TLUDs.

See also the attached about making stove structures.   Reminds me of the low density bricks by Ken Goyer and others that come together for a hexagon shape, but for only one size of stove.   Robert's design is expandable.   Robert, please revise with your suggestion of possible "lockable angles" (by having specific short straight segments instead of smooth curve on the ends.)   I like it!!!!

Robert, thanks again for providing this info.    This could be discussed at Stove Camp starting 10 days from now.

If replying to Robert, note that he probably does not subscribe to the Stoves Listserv, so be sure to include his email address in 
the recipients.            "Haston, Robert E LTCOL USAF (US)" <robert.e.haston.mil at mail.mil>

Paul
Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD  
Email:  psanders at ilstu.edu   
Skype: paultlud      Phone: +1-309-452-7072
Website:  www.drtlud.com

-------- Original Message --------
Subject:	Paper/biomass fuel, cooking fuel - terrorism link, potential new stove brick design. (UNCLASSIFIED)
Date:	Tue, 01 Jul 2014 17:58:40 +0000
From:	Haston, Robert E LTCOL USAF (US) <robert.e.haston.mil at mail.mil>
To:	psanders at ilstu.edu <psanders at ilstu.edu>

Classification: UNCLASSIFIED
Caveats: NONE

Dear Dr. Anderson,

You might remember me sending you an email about mixed plastic/biomass (i.e. waste from remote military bases) as cook stove fuel.

Since then the university of Athens expanded on the ASU Biodesign’s meta study. They did burn tests that proved the concept.

Converting Biomass and Waste Plastic to Solid Fuel Briquettes. http://www.hindawi.com/journals/jre/2013/360368/

Once again I am deployed overseas (Djibouti Africa). The smoke from poorly operated waste incinerators/open burn pits (which always seem to get installed upwind) is the worst I have ever experienced.

The latest twist here is this: Illegal Charcoal Trade Funding Somalia's Al-Shebab.   http://allafrica.com/stories/201406261350.html You probably already know about the expanding deforestation due to the growing charcoal trade south of here.

Miniaturizing the waste to fuel process seems reasonable once you get past misplaced fears of burning plastic. The process is straightforward: pick the cleanest plastics, combine them in the optimal ratio, and form them into briquettes or pellets designed specifically for “mini-incinerator stoves”. This sure looks cleaner than the “certified safe” burn pits on our bases. Instead of EPA standards, you only have to beat the emissions of an sheep dung fire. 

I guess the next step would be to work on designing and lab testing custom designed fuels for different stove types. Aside from the size and shape, I guess the only other factor is whether it would be best to incorporate the plastic in the pressing or to hot coat the briquettes/pellets afterward.  This would increase their water resistance.

Of course getting the military behind this would require some expert bona fides. This is a pretty good location to field something. Our hanger sits right next to the Army Civil Affairs Company. KBR just got another 53 million dollars to run the camp. I am sure they are interested in ways to fix their waste stream problems and polish their tarnished reputation. Unlike Iraq or Afghanistan, this base is expanding.

Also, I was thinking of making an expandable cook stove – like adding rocks to make a campfire bigger. I came up with a design for cove and bead bricks that you can strap together like barrel staves. The design (along with a matching pedestal brick) eliminates the need for mortar.

I attached a simple sketch of a top-down view. It would probably have a base molded to accept the bricks. I figure you could add some features (bumps, tabs, pins, etc.) to lock the bricks at 45 and 60 degree angles. I am probably missing something, but it looks like an extremely useful design to me. It would sure be cool to see it adopted.

Feel free to forward this to your cohorts.

Thank you for your consideration and all your great work.

Lt Col Robert Haston
303rd Expeditionary Rescue Squadron
Camp Lemonier, Djibouti Africa

Classification: UNCLASSIFIED
Caveats: NONE

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