[Stoves] Fw: Grass Gasification

[Paal Wendelbo]

From: Paal Wendelbo 
Sent: Sunday, August 25, 2013 9:24 PM
To: Paul Anderson 
Subject: Re: Grass Gasification

Dear Paul A

It is more than 20 years ago I first made this tests with grass as fuel in a refugee camp in Malawi. Some refugees cleared a land and piled it up and put fire on it. A lot of smoke arise for hours around the whole area. I took 2kg grass and weeds of different types, made a Peko Pe from a 2o liters tin, stamped it round a 50mm stick in the middle and was boiling 3 liter of water for more than an hour without any smoke. All my notes from that time were lost so I can’t go into details. By I have tried it several times and it works later and it works. 

Grass and weeds can be stamped into a TLUD-ND with a draft hole in the middle. Straw, reeds and papyrus has to be cut in length of the combustion chamber and placed vertical and loose. The especial with grass and straw is it doesn’t collapse when flame is ended, and the pot comes close the glowing mass with high enough temperature for still cooking. The time of flame and glowing is almost the same. The diameter of the stoves 160 mm for straw and 180 mm for grass.

I remember we used straw for melting aluminum for making pots and did some small scale blacksmithing with papyrus. A 10mm iron bar was yellow/white after few minutes into the glowing.

I still have some pictures and d notes from North of Uganda, but not electronic, but they can be copied if some are interested. At that time there was very little attention to that type of work, mostly due to the charcoal business.

With regards Paal W 


From: Paul Anderson 
Sent: Saturday, August 24, 2013 8:23 PM
To: Paal Wendelbo 
Cc:  ; Discussion of biomass cooking stoves ; Doc Anderson 
Subject: Re: Grass Gasification

Stovers,

I am forwarding a message from Paal Wendelbo this is quite informative about pyrolysis of grass fuel in his Peko Pe.    It should apply to all true TLUD stoves with full diameter access to the fuel chamber.

I now ask Paal:   Please discuss the "grasses".   There are so many types.   Do your comments / experiences relate to certain types (such as those with nice stiff stems, which species??) more than to other types of wavy / leafy  grasses?

Also, the diameter of you stove is important to get 1/2 kg in a bundle that is 20 cm tall.    Did you have stoves with different diameters?

Very important info you gave about difficulties when the grasses are simply packed in (not in bundles of vertical stems).

Paul

Paul S. Anderson, PhD  aka "Dr TLUD"
Email:  psanders at ilstu.edu   Skype: paultlud  Phone: +1-309-452-7072
Website:  www.drtlud.comOn 8/23/2013 3:09 AM, Paal Wendelbo wrote:

  Dear Janitha Bandara

  Thanks for mail. I can’t say I have done any gasification researches for grasses, but In have done a lot of practical use of straw ( hyperrenia rufa) as fuel for household cooking in Uganda in 1995, with the Peko Pe TLUIFD-ND stove. We found the best way to utilize the straw was to cut it to the height of the stove, 200 mm, made it into bundles of ½ a kg and put it into the stove. The bundles was burning nicely without smoke for about 20 minutes on the flame and another 20 minutes on the glowing since the glowing straw did not collapse like other types of fuel. 

  You have a nice clean flame on the generator, probably a bit too high, depend what kind of use it is designed for. I should like to know more about the aim of the construction. Is it to produce gas or to produce energy for something else?

  Regarding I insulation, be aware of higher temperature will strain the metal in the combustion chamber, air could be better with double function, cool down the temperature  on the metal and the same time preheat secondary air.

  If you stamp grass into the generatorto prolong the process, there will be a problem of air going through, a 50 mm vertical channel in the middle  will solve the problem.

  With regards Paal W.  paaw at online.no
  From: janitha chandimal 
  Sent: Wednesday, August 21, 2013 11:32 AM
  To: paaw at online.no 
  Subject: Grass Gasification

  Dear sir, Pall Wendelbo, 

  I m writing this according to the information got from Paul Anderson, Golden, Colorado and He said that you had done gasification researches for grasses. Me too is doing my masters research on gasification of guinea grass (Panicum maximum) and I have got some fine results. It is a small scale system having 700 mm height and 200 mm in diameter. But the main problem involved is the quick exhaustion of feed stock and the compaction of grass. I have here by attached my drawing and few pics of the flame. looking forward to hear from you soon. Thank you. 

  Best regards 


  -- 

  Janitha Bandara
  PG Student, Dept. of Chemical & Process Engineering, University of Moratuwa, Sri Lanka
  0094713058696

  Take Hands in Reducing Consumption, Saving Resources & Protecting Environment

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