Reducing Gas Emissions from Compost with KMI Zeolite

In this small scale example we illustrate the dramatic reduction of greenhouse gas emissions in compost with the addition of KMI Zeolite.

As little as 10% zeolite powder, added into the compost, can reduce the amount of gasses that are emitted. We also illustrate the powerful moisture retention of zeolite when combined with compost.

A small amount of fresh compost was placed into three containers. In the first, 0% zeolite was added.  The remaining two were given 10% and 15% KMI Zeolite by weight. The zeolite was mixed into the compost dry.

Each bucket was given a drain hole on the bottom to allow the excess water to run out. Then we placed collection buckets under each compost bucket.

Water Retention

We poured 16oz of water into each bucket, allowing the excess to pour out of the drainage holes and into the collection buckets below.

The results showed that zeolite significantly improved the water holding capacity of the compost when compared to the control.

10% and 15% zeolite improved water holding capacity by 60 – 100% respectively!

Gas Emissions

All three containers were then sealed off, with balloons attached to the lids, with a hole allowing for the gasses to escape up into the balloons. The following images show the before and after 24 hours.

The results were clear. Even at 10% zeolite the gas emissions were almost unnoticeable in the balloon. The balloon on the lid of the 10% zeolite container only barely inflated with a slight bit of gas. The balloon on the lid of the 15% did not change at all.

The balloon on the lid of the 0% zeolite compost bucket was inflated to about 10x the size of the balloon.


Based on the results of this initial test we can see that zeolite may be able to reduce the amount of gas emitted from compost drastically.

KMI Zeolite is highly absorbent, has a high cation exchange capacity and has a negative molecular charge.