Modified Biogas Digester

Some common sense I used and some simple modifications in the currently available biogas digester designing I made. This can help in increasing biogas production immensely and will make biogas very much commercially viable. Must see page for all those out there who believe that to make differences you don’t need to be an Einstein, a common sense can be more than sufficient.

With the depletion of the conventional energy sources like fossil fuels, uranium, etc, demand for renewable energy sources is increasing.

Now, Biogas is in the race of becoming one of the major renewable energy of future. But, it is suffering from certain setbacks which make it quite difficult to produce it at commercial level. However instances are their where many countries are producing at a large scale. But, still its current method has not gained worldwide acceptance as other sources like oil, coal, natural gas, wind, etc. has gained.

Some setbacks are:

  1. Removal of impurities like carbon dioxide, etc at a cheaper cost i.e. to reduce the purification cost of biogas.
  2. Increasing the output of gas.

So, taking that into consideration I suggest two modified models of biogas digester which might make its use a lot more favorable.



So, my design shown above is meant to solve the above to problems to some extent.

In my design I have incorporated an immobilized Carbonic anhydrase into the digester. This enzyme will catalyze the conversion of carbon dioxide (CO2) to carbonic acid (H2CO3).

Now, this carbonic acid can be used to make sodium carbonate (Na2CO3) or sodium bicarbonate (NaHCO3) by adding sodium hydroxide (NaOH).

H2CO3 +NaOH → Na2CO3 + H2O

Now, this way our two problems will be solved:

  1. The carbon dioxide produced during anaerobic fermentation will be simultaneously converted to sodium carbonate (Na2CO3) or sodium bicarbonate (NaHCO3), which has many applications like acidity regulator, anticaking agent, raising agent, stabilizer, etc.
  2. Secondly, more free space is available for methane to occupy as the space which was previously used carbon dioxide is now free. This will help in generating more gas in the given space and time.



In this model, rather than adding NaOH in the digester, carbonic acid sent to the overflow tank can be used as carbon dioxide source. Since, carbonic acid is unstable; it will dissociate to produce carbon dioxide which can be sent to dry ice production chamber for producing dry ice. Now, this dry ice can be used as a cooling agent, etc.

So, in this way we can modify the biogas digester to make biogas production more efficient and commercially viable product.

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22 Responses to “Modified Biogas Digester”
  1. Dhalebiogas Says...

    On February 12, 2009 at 9:26 am

    I have gone through you improved designed but i would like to
    now have many plants you have installed in India please give some of the address so i can meet and get the retuslt from the
    beneficiaries using your designed more over the designed improved by you can give more result

  2. Dhalebiogas Says...

    On February 12, 2009 at 9:39 am

    I am very much impress with your designed
    I would like to propoget your idea all over
    India please reply on give E-Mail
    Thank you
    Controling Pollution
    all over world

  3. ur guide Says...

    On February 12, 2009 at 12:45 pm

    Thank you for your wonderful comments and for your interest in my designs.

    If you r interested, then please give me your contact information. I will contact you.



  4. M B Says...

    On March 30, 2009 at 10:14 am


    I am interested in knowing more about this. Is it feasible and viable for commercial production.

    M B

  5. j8a Says...

    On April 5, 2009 at 11:05 am

    I seems to be really feasible, do you think that the perfomance is better than conventional biogas digestors used in tropical wheather?. I mean the comparisson with UASB devices. I will very appreciate your comments.

  6. kelvin Says...

    On April 16, 2009 at 1:37 am

    we are biogas plant manufacturer and designer in southern China, please see for more info. Thanks!

  7. ur guide Says...

    On May 15, 2009 at 11:32 pm

    Hi all,

    Thank you all for your kinds comments.

    With regards,
    Ur guide

  8. ur guide Says...

    On May 15, 2009 at 11:34 pm

    hi M B and J8A,

    Thank you for ur interest. It hasn’t been compared yet with different devices. When any such thing occurs I will surely update you all.


  9. Otieno Says...

    On June 3, 2009 at 5:22 pm

    I’m interested in your work, whats your email address, iam from kenya

  10. ur guide Says...

    On June 7, 2009 at 1:02 am

    Hello Otieno,

    You can contact me at

  11. amea Says...

    On February 6, 2010 at 9:30 am

    very interesting article for me. thanks for your work.

  12. ur guide Says...

    On February 7, 2010 at 7:51 am

    Thanks Amea,

    For you comments and support.

  13. john malila Says...

    On June 30, 2010 at 6:47 am

    you designs are excellent can you give me a step by step build it myself process

  14. Queeneth Onyinyechukwu Ibeme Says...

    On August 14, 2010 at 4:43 pm

    Your design is interesting can i have a detailed description of this modified digester, what is the source of your enzymes (carbonic anhydrase) and regents. i know little of chemical compounds.

  15. ur guide Says...

    On August 22, 2010 at 3:56 pm

    HI all,

    It is currently just the design. I am looking for someone who can help me to do this project, I have found many places where similar kind of work goes. But, still not successful in finding someone who can help me out with it.

    Once done, I will surely give you a step by step process of making it.


  16. jerzhkiemanuel Says...

    On January 7, 2011 at 2:21 pm

    I\’m am also interesting with your design, can i have a detailed description of this modified digester? Because its been a long time that im thinking on how to make a biogas and use in my household.

  17. ur guide Says...

    On January 11, 2011 at 2:46 pm

    HI jerzhkiemanuel,

    This idea is still in conceptual stage and needs some financial support for further studies. If any more work is done, I will update you.


  18. B Murali Krishna Says...

    On April 1, 2011 at 9:20 am

    Dear Rahi,

    Your work is quite useful in many a ways. Carbonic Anhydrous enzymes were hitherto used in pharmaceutical applications. I understand from the comments that you need some support for research and application. I have also sent you an email. You may reply me for further association.

    Murali Krishna

  19. B Murali Krishna Says...

    On April 1, 2011 at 9:27 am

    Dear Rahi,

    Contact me for support and application on my

  20. Dick Mariano Says...

    On September 24, 2011 at 6:10 am

    Hi Rahi,

    I am presently building a biogas system in my piggery farm somewhere in the Philippines.

    My plans are to produce biogas for households and reuse the water by filtering process… to irrigate fruit trees and other plants as I have no means of discharging waste through bodies of water. Use also the slurry for organic fertilizer.

    If you don’t mind I would like to enlighten my small knowledge and incorporate your experience on the matter.

    Please let me know of your email address so we can communicate more. Thank you!

    Kind regards,
    Dick Mariano

  21. Kennedy Letshego Mangwane Says...

    On September 28, 2011 at 8:13 am

    I’m very much interested on such a development. Being an African, I would like to venture in such a project on commecial baises, as an alternative source of energy.

    Would you update me on any recent developments.



  22. isaac newton kokoti Says...

    On February 14, 2013 at 5:52 pm

    i am also interested in ur designs. this is my contact

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