“Bio gas”, a new post from Nepal

While we were visiting Chaaling community to know about the solid waste management, we encountered the use of bio gas in one of the homes. Bio gas has been in use in Nepal as an alternative to the fuel wood. The international volunteers as well as I being a city dweller till now hadn’t seen one being operated. I had learned about bio gas and its uses in my classes but this was the first time I actually saw it.

Biogas typically refers to a mixture of different gases produced by the breakdown of organic matter in the absence of oxygen. It is a renewable energy source. Biogas can be produced by anaerobic digestion with anaerobic organisms, which digest material inside a closed system, or fermentation of biodegradable materials.[1]

Biogas is primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of hydrogen sulfide  (H2S), moisture and siloxanes. The gases methanehydrogen, and carbon monoxide (CO) can be combusted or oxidized with oxygen. This energy release allows biogas to be used as a fuel; it can be used for any heating purpose, such as cooking. It can also be used in a gas engine to convert the energy in the gas into electricity and heat.

In Chaaling, Bio gas as the locals called it ‘gober gas’ as it uses cow dung (gober) to be operated. There they said that the bio gas plant had been installed with the help of government project which provided 50 percent subsides. They had the plant for almost 5 years and has been benefiting their life since then.

The bio gas plant has a tank or a container that collects the waste, a pipe that is linked to the household gas and a manure collection pit. Each day the animal excreta are fed to the bio gas plant. According to the locals, at least 10 kg of animal excreta has to be fed to it. The gas that comes from the plant is used for cooking in the household. The manure that is left in the pit is dried and later used as an organic fertilizer in their fields. If the cow dung is not added to the plant, the plant works for around 15 days for a family of four. The gas produced does not smell nor has any side effects to the environment.

The international volunteers hadn’t known about this simple technology and were interested to see and apply it in their villages back home. Since bio gas doesn’t require very high cost or high technological manpower, it is easy to be used. This reduces the organic solid waste, reduces the dependency on fuel wood and LPG gases, and produces very effective organic fertilizers.

 ~ Shrija Tuladhar