The gas produced when waste is permitted to decompose in an anaerobic environment is called biogas. It is formed from natural waste like animal manure, sewage and decomposing plant matter. Biogas is considered a sustainable source of energy that can take the burden off of the depleting stores of fossil fuels. It is collected in biogas plants where it can be used as an alternative to conventional gas. Does this Spark an idea?
Dome Plants
Biogas is stored in two types of domed plants: floating dome and fixed dome. In the floating dome type, the waste is mixed with water in a well beneath the ground. This well is covered with a floating stainless steel cap. As the waste decomposes, the gas collects inside the floating steel dome. The fermentation process takes about 50 days, and then the gas is released via a valve in the steel dome. The fixed dome variety of biogas tank is similar in design as the floating dome, but the fixed dome is made out of concrete and does not float on top.
Balloon Plants
Another type of plant for collecting biogas is called a balloon plant. Here, the gas created from the decomposing waste is not collecting in a dome, but a balloon made out of flexible PVC. This style of plant may be preferable since dome maintenance is not needed. As the gas is produced, the PVC balloon expands to keep collecting it. Once the balloon reaches capacity, the gas is drained out so it can be filled again. Although balloon plants are cheaper and easier to build and maintain than a dome style plant, they do not last as long and are not as dependable as dome plants.
Water Jacket
A third style of biogas plant is called a water jacket plant. Much like a floating dome tank, the water jacket plant relies the mixture of the organic waste with water. But rather than float atop the waste itself, the dome sits atop a track that is filled up with water. This allows the dome to float and move in concord with the pressure in the tank. Also, since it is separate from the waste, this is a more sanitary design and is easier to maintain than domes that come into contact with the waste. These plants also last longer with less corrosion than the domed varieties.
Tags: floating dome, dome fixed, dome fixed dome, fixed dome, with water