Home > Engineering, Kenya, Science, Scrap Heap, tinkering > Building an Anaerobic Digester

Building an Anaerobic Digester

We have built the simplest of anaerobic digesters to prove the theory. We did not follow any of my designs due to cost constraints, but have built it so that it can be improved later.

Searching the market for fittings

A locking tap for the outlet

This is what we used for the feed stock

Getting it into the drum was messy

Sealed up and ready to start producing methane

A balloon shows that gas is being produced.

Local resident, Junior, wants to know all about it.

Of course, little boys love smelly gas, the smellier the better.

We're cooking on gas!

We intend to add a storage drum with a water-filled header tank to provide a near constant pressure.

  1. Helelen M Fahre
    May 2, 2010 at 15:01


    Your post came up in one of my google alert emails,and I think it’s incredible what you are doing.I’m currently working with an inventor and his anaerobic digester system- I want to try and get the simple ones to Africa,and particular Kenya and Tanzania where I have contacts,I think they could do a world of good,like you so neatly proved.

    Great work,I hope we can have a chat some time,maybe we could help each other?
    At least for information

    Best wishes

    Helene MF

    • May 2, 2010 at 15:24

      It looks like we have a lot of wishes in common. Please contact me on david at kcisupport dot plus dot com

      • Muriuki
        July 8, 2013 at 22:42

        Hi. How far have you gotten with this so far? I have ten cows and I really cant afford the cost of a biogas system. I still want to convert the cow dung into fertilizer for my shamba. Any help is most welcome

      • August 25, 2013 at 16:51


        Sorry about the delay in replying. Since 2010, I have been recovering physically and mentally from a serious road accident witch occurred near Nakuru. I have not been back to Kenya since, and I doubt that I ever will.

        As to your problem, my first biogas system cost me about KES 4,000 to build, just a single oil drum and some pipework. The trick is to expell all air from the system for it to work. The same goes for producing fertilizer. Anaerobic just means without air. So if your cow dung is stored in an air-free container, methane will be produced. It will last for about 6 months without need to renew it. The resulting mess after the six months is fertiliser.

        Good luck with your shamba. Let me know how you get on. Where are you located?


  2. drewable
    May 4, 2010 at 04:20

    Your project reminded me of a book I read many years ago. They give a small description of a methane digester with a drawing of a system. You may or may not find it valuable.

    It’s on page 123 of
    Back to Basics: A Complete Guide to Traditional Skills By Abigail R. Gehring

  3. May 4, 2010 at 08:35

    @drewable – Thanks for that. It is funny, but I have read a lot about anaerobic digesters of all sizes and never have I found a ratio for feed stock to water – and this book is the first that cites chicken manure. It is usually stated that there is too much ammonia in it.
    I shall keep working and experimenting and I will get there one day, the goal being a cheap and efficient system that will help poor communities.
    Once the digester is worked out, I will need to find a source of cheap burners, maybe home-made.

  4. May 5, 2010 at 19:12

    I think what you’re doing is wonderful. Thank you!

  5. jke
  6. December 5, 2010 at 14:31

    gr8 resrch bro…

  7. December 6, 2010 at 14:07

    My business is really thankful on the author of the post for making this lovely and informative article live here for us. We actually appreciate ur effort. Sustain the good work. . . .

  8. December 7, 2010 at 17:12

    Interesting post, I totally agree with other commenters, Keep us posting

  1. May 3, 2010 at 11:38
  2. May 4, 2010 at 02:00
  3. May 4, 2010 at 02:55
  4. May 4, 2010 at 03:05
  5. May 30, 2010 at 03:37
  6. February 16, 2011 at 09:19

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: