Consider the following data for a domestic biogas plant:
Number of cows = 5
Retention time = 20 days
Temperature = 30°C
Dry matter consumed = 2 kg/day
Biogas yield = 0.24 m3/kg
Efficiency of burner = 60%
Methane proportion = 0.8
Heat of combustion of Methane = 28 MJ/m3
Density of dry material in fluid = 50 kg/m3
The power available from the digester will be nearly
1. 16.2 MJ/clay
2. 24.3 MJ/day
3. 32.3 MJ/day
4. 48.6 MJ/day