Compost Process Overview
1 February 2012 | HOTBIN Composting
Try to keep to the green column as best you can.
Composting - the process |
| Mass balance | What Goes In | Energy balance |
| |
| Sum of materials in C= ~50% | Nutrients
Carbon/Nitrogen, trace elements
Surface area, particle size
Energy and water balance
In/out lists (food, grass, garden waste) | Sum of energy in
~2400 kJ/kg |
| |
| | Conditions | |
| | Aeration / Oxygen
Temperature
Water / moisture
Ph | |
| Sum of conditions |
| Oxygen level (determines dominant bacteria) |
Aerobic
(>6-21%) | Anaerobic (<6%) |
| |
| Composting Equipment |
| HOTBIN
size
insulation
valve/aeration
other | AD plant
closed vessel
gas system |
| | |
| | |
| Aerobic microorganisms (bacteria, insects etc)
Oxygen
Pests and vermin | Anaerobic microorganisms (bacteria) No oxygen
SO3, NO3
Pests and vermin |
| Decomposition intermediates |
| Odour (Aerobic)
low VP
fragrant VOCs | Odour (anaerobic)
low VP pungent VOCs, H2S |
| What comes out |
| Sum of materials out | Compost (C 25%)
Quality
Ease, labour
H&S
Environmental Carbon dioxide & Water | Methane
Energy recovery
Ease (lack of small scale)
H&S
Environmental Water | Sum of energy out |
| Mass balance | Humus (C<3%) | Digestate (C10%) | Energy balance |
