Based upon digester volume how to determine the quantity of incoulum and substrate to be fed for the first set up of domestic biogas plant.
Please suggest me related article that could help to understand the concept.
Jeewan Khadka what kind of substrate you are using for digestar set up? If it is plant waste then their physico-chemical properties need to check!
Accordingly the ratio (substrate-inoculum) and loading rate can be calculated.
There is no mathematical formula to determine the quantity of incoulum to set up a new digester plant ,but it has been roughly estimated based on the size of the reactor set-up. It has been often used about 5-10 kg in the case of medium and big size pilot-scale reactors and it may be small in the case of nab-scale set-up. I just recommend for your to see what the previous literature used quantity based on your set-up scale size.
Jeewan Khadka considering the digester size i can add my views
Determining the quantity of inoculum for a new digester involves considering several factors:
1. Digester volume: The size of the digester tank.
2. Desired microbial density: The target concentration of microorganisms in the digester.
3. Inoculum quality: The microbial density and activity of the seed slurry.
4. Substrate type and quantity: The type and amount of organic matter to be digested.
Here's a general approach to estimate the inoculum quantity:
1. Calculate the digester's working volume: Consider the tank's volume and the desired liquid level.
2. Determine the desired microbial density: Typically, 10-20% of the digester's working volume is considered a good starting point.
3. Analyze the inoculum quality: Measure the microbial density (e.g., volatile suspended solids, VSS) and activity (e.g., biogas production rate) of the seed slurry.
4. Calculate the required inoculum quantity:
- Inoculum volume (m³) = (Digester working volume x Desired microbial density) / Inoculum microbial density
Example:
Digester working volume: 1000 m³
Desired microbial density: 15%
Inoculum microbial density (VSS): 50 g/L
Inoculum volume = (1000 m³ x 0.15) / 50 g/L ≈ 30 m³
So, approximately 30 cubic meters of inoculum would be needed to seed the digester.
Keep in mind that this is a rough estimate and may need to be adjusted based on specific conditions and experience. Consulting with a biogas expert or conducting further research may be necessary to ensure optimal digester performance.