[Digestion] Dry fermentation in developing countries

Ken Calvert renertech at xtra.co.nz
Fri Oct 29 01:03:22 PDT 2010

Yvonne,  Might as well make your answers all in one go!
What level of  machinery/technology are you visualising for your project?   Will your farmers be working this plant with shovels and wheel barrows to load and unload the digester?  Will they have a small tractor and a trailer?
Could the tractor have a 'front end loader on it?  I guess a Bobcat loader would be too much to ask for?   Ken C.
  ----- Original Message ----- 
  From: Voegeli, Yvonne 
  To: digestion at lists.bioenergylists.org 
  Sent: Thursday, October 28, 2010 9:53 PM
  Subject: [Digestion] Dry fermentation in developing countries

  Dear all,


  I like to start a new discussion on a different topic, namely the dry-fermentation process (discontinuous) similar to the digesters developed by the companies Bekon or Bioferm in Germany. The organic waste is filled batch-wise into simple garage-like digesters for about 30-40 days.


  Experts report that this process has a high potential for application in developing countries as it has the simplest design and the solid waste digesters are the least expensive ones. Also, substrates that lead to operating problems during wet fermentation due to their structure or the proportion of impurities they contain can still be processed using dry fermentation methods. However, up to date, there is no experience with this technology in developing countries. Therefore, our idea is to develop a dry-fermentation biogas plant adapted to the situation in developing countries using locally available material.  


  After visiting a Bekon biogas plant in Switzerland, I'm especially concerned regarding the opening of the digester for emptying and refilling. Before opening the door, the digester has to be vented in order to avoid a gas-air-mixture which is explosive. This installation seems to me rather complicated.


  - Is anybody of you familiar with discontinuous dry-fermentation systems and has an idea how the security can be assured in a developing country context? Is it possible to install a simpler venting system?

  - Likewise, when removing the drum from a floating-drum digester for emptying, how is ensured that at no time an explosive gas-air-mixture occurs?


  Thanks for your ideas,



  Yvonne Vögeli
  Eawag / Sandec
  Überlandstrasse 133
  P.O. Box 611
  8600 Dübendorf
  Phone: +41 (0)44 823 54 20
  Fax: +41 (0)44 823 53 99
  yvonne.voegeli at eawag.ch



  Digestion mailing list

  to Send a Message to the list, use the email address
  Digestion at bioenergylists.org

  to UNSUBSCRIBE or Change your List Settings use the web page

  for more information about digestion, see
  Beginner's Guide to Biogas
  and the Biogas Wiki http://biogas.wikispaces.com/

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/digestion_lists.bioenergylists.org/attachments/20101029/2ca5e0fa/attachment.html>

More information about the Digestion mailing list