WHY MY GAS IS NOT BURNING?

When I first initiate my digester with zero knowledge about biogas my favourite question was why is there no any gas produced? So you are very lucky if there is gas production by the new digester because carbon dioxide will come out first in the beginning before then methane. You have to understand that biogas is actually mix of several type of gas like carbon dioxide, methane and other inert gas. Along the process of biogas production, in the beginning of chain reaction, acidification will first occurr thus producing carbon dioxide. It is normal to have carbon dioxide in the very beginning. It is a positive sign that your digester is working well and will produce methane a bit later according to the chain reaction. Unless your digester is continuously producing carbon dioxide after months of starting then you have to start worry there might leakage somewhere along digester system.

Biogas Bag for Storage

Storage using gas bag is easy. Choose bag size big enough for own use or otherwise you will suffer since every time its full then you have to burn or flare the biogas for cooking. A bag full of gas you may not want it to get full to maximum because if it full will prevent additional gas going into it. What happen next is the excess gas will push the slurry out of digester. 

Vertical Biogas DIgester Design

 Source: Joel Canaria

 Observe a typical design of a digester.

Inlet - feeding occurs here having the largest diameter among all.

Gas outlet - biogas produced from the process goes out thru here connected to external storage.

Overflow - where slurry displaced by a new feeding goes out thru here.

Stirrer - to make sure agitation takes place. Optional for some practitioner.

Drain - to let the accumulated sediment to flow out thru to be discarded after operating for sometime. 


















Need Biogas Now?

Horizontal Biogas Digester Design

I would like you to check out this design from a friend, more details please check under the QR code. Usually the blue tank converted as biodigester in a vertical form. This is quite different which someone could try on horizontically.

Source: Jørgen Rasmussen (A Clean New World)


 
Or for more explanation please refer to below video:


Floating drum system for biogas storage

 The system consist of two components:

1. The floating drum that has inlet and outlet for biogas. Inlet will let the biogas into the drum to be stored. Outlet is to let the biogas out when it is needed so should there be valve installed to control the process.


2. The base drum that contained water act as a platform for upper drum to float when there is gas produced. A steel guide installed to make sure the floating drum won't fall to the side.



So both drums are of different volume

a. floating drum is 160 liter

b. base drum is 200 liter

source: Biogas DIY FB Group

Biogas digestate as fertilizer

 

No mistake in deciding to pursue biogas generation. Food waste could be managed well environmentally friendly way. Also the byproducts could also useful for agriculture. After digestion the solid waste leftover could be turned into powder after drying and grinding. Inside its already contained beneficial microbes such able to fixing nitrogen in soil. Or its properties could be enhanced more via biotechnology application towards enrichment and value adding of the existing waste material.
 
Your effort will be worth it.
 
But be careful to call your digestate as a biofertilizer make sure it contains beneficial microorganisms (eg. Nitrogen fixing and/or phosphate solubilizing and/or potassium solubilizing, etc) to enhance the properties of the soil where you applied the digestate so that your plant grow better compared to untreated soil. Another thing, biofertilizer should contain enough no. of beneficial microorganism compared to background microflora or otherwise won't show the expected effect if suppressed by other dominant or large no. of other microbes inside the digestate.
 
fresh digestate
 
 
digestate in powder form after drying and grinding
 

 two useful microbes from digestate