Compost Pile Thermal Succession

Pile Recipe

Carbon : Nitrogen ratio 28:1

Moisture 65%

Pile insulation (size) Medium

Simulation speed 1×

Pile State

Mesophilicmicrobes waking up

Core temp

20 °C

Day

0.0

Oxygen (core)

100%

Decomposed

How it works

Aerobic microbes oxidise the food-waste substrate for energy, releasing heat:

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + heat

The pile's core temperature follows a heat balance each simulated hour:

dT/dt = (Q_gen − Q_loss) / C
Q_gen = k · S · f(T) · f(M) · f(CN) · f(O2)
Q_loss = h(size) · (T − T_ambient)

f(T) — a bell curve: activity is low below ~20°C, peaks near 58°C (thermophilic optimum), and collapses above ~70°C as even heat-loving microbes die off.
f(M) — moisture factor, optimal at 60–80%; too dry starves the microbes, too wet drowns them and starts pushing the pile anaerobic.
f(CN) — carbon:nitrogen factor, optimal near 25–30:1; far outside that range (too much "brown" or too much "green") slows decomposition.
f(O2) — oxygen at the core is consumed by microbial respiration and only resupplied by physically turning the pile; if it isn't turned, the core suffocates, activity collapses and the zone turns anaerobic (grey-green, slow, smelly).
Substrate S depletes as decomposition proceeds, so heat generation eventually falls even with perfect conditions — the pile then cools and cures.

Real compost passes through mesophilic (20–45°C) → thermophilic (45–70°C, pathogen/weed-seed kill) → cooling → curing phases over weeks, exactly what this model reproduces at accelerated speed.

Hot / thermophilic core Cooler outer layer Oxygen-starved (anaerobic)

⚠ Couldn't load the 3D engineThree.js failed to load from the CDN. Check your connection and reload.