How Biogas Works

1

What Is Biogas? 

Biogas is a special kind of gas made when leftover food, plants, or animal poo break down without any air. Tiny invisible helpers called microbes eat the waste and make a gas called methane (meh-thane), which we can burn for energy to cook food, heat homes, or even run buses!

Think of it like this:

Food Scraps

No Air

Microbes

Biogas

Fertilizer

2

How Does Digestor Works?

1

Feed

Add waste + water to make a thick goop.

2

Digest

Microbes in the tank eat the goop without air-this is called anaerobic digestion.

3

Collect Gas

Methane gas bubbles up and is stored in a dome or balloon.

4

Release Slurry

The leftover mix (“digestate”) can be used as fertilizer.

3

Why Biogas Matters?

Biogas isn’t just cool science-it’s good for the planet too! Let’s see why:

Green Energy

Biogas is a type of clean, renewable energy.
It can replace petrol and coal, which pollute the air and cause climate change. When we use biogas, we help keep Earth cooler and the air fresher!

Zero Waste

When we make biogas, the leftovers-called digestate-can be used as natural fertilizer. That means nothing is wasted! The food scraps or animal poop help grow more plants.

Real Life Uses

People all over the world use biogas every day!

  • Farmers use it to run machines and power lights in barns
  • Families use it to cook food or heat water
  • Some cities in Europe even have buses that run on biogas!

4

Meet the Microbes!

These tiny helpers break food into methane in four stages: hydrolysis, acid formation, making acids and then methane!

“Hydrolysis → Acidogen → Acetogen → Methanogen”

5

Try It Yourself! - Make Your Own Biogas Jar

You can try a fun mini-experiment at home to see how biogas is made!

What You'll Need:

  • A clean, empty glass jar (jam jar or mason jar)Some warm water
  • A few kitchen scraps (like banana peel, rice, spinach bits)
  • A balloon
  • A rubber band
  • A spoon to stir

What to Do:

Fill the jar halfway with warm water.

Add a small handful of soft kitchen scraps. Mix it all into a thick goop.

Stretch the balloon over the top of the jar and seal it tightly with a rubber band. Place the jar in a warm, sunny spot.

Wait and watch! After a few days, the balloon will start to inflate with gas made by microbes!

6

Glossary

Anaerobic

“Without air.”

Digestate

The smelly but plant‑friendly leftover.

Methane (CH₄)

The gas you can burn for energy, made by microbes.