Using a Small Scale Biodigester to Measure and Compare Methane Gas Production from Cow, Goat, and Sheep Dung

The purpose of this experiment was to determine what type of farm animal dung cow, goat, or sheep would emit the most methane gas to be used as an alternative fuel source for financially weak regions. Methane gas is a natural fuel source that is easily captured and combusts which makes it an efficient, accessible, renewable replacement for non-renewable resources or fossil fuels like coal or gas. A manometer was constructed to measure the displacement of water by methane gas that was emitted from slurry made of animal dung and tap water. The displacement of water over five days was observed to determine which type of dung emitted the most natural gas for collection to be used as fuel. Both an ANOVA test and descriptive statistics were used to analyze the data.

The original hypothesis stating the cow dung would emit the most methane gas was rejected. Due to goat dung being the greatest dry biomass compared to the cow and sheep dung, it contained a higher concentration of carbon to create more methane gas. The animal dung that emitted the most was goat with an average of 26.16 cm of water displacement by gas, followed by sheep with 14.22 cm, then cow with an average of 5.59 cm. The information from this experiment would be used by many financially burdened third-world countries around the world to manufacture simple and inexpensive biodigesters that would use dung to emit the most methane gas. Thus, their sources of fuel would be expanded through different methods of natural resource extraction.

Research Done By:

Marla Nazee
Sterling Heights High School

Mary Whitney
Fraser High School