Biogas typically refers to a
mixture of different gases produced by the breakdown of organic matter in the
absence of oxygen. Biogas can be produced from raw materials such as
agricultural waste, manure, municipal waste, plant material, sewage, green
waste or food waste. It is a renewable energy source and in many cases exerts a
very small carbon footprint. Biogas can be produced by anaerobic digestion with
anaerobic bacteria, which digest material inside a closed system, or
fermentation of biodegradable materials. Biogas is primarily methane (CH4) and
carbon dioxide (CO2) and may have small amounts of hydrogen sulphide (H2S),
moisture and siloxanes .Biogas is produced as landfill gas (LFG), which is
produced by the breakdown of biodegradable waste inside a landfill due to
chemical reactions and microbes, or as digested gas, produced inside an
anaerobic digester. By converting cow manure into methane biogas via anaerobic
digestion, the millions of cattle in the United States would be able to produce
100 billion kilowatt hours of electricity, enough to power millions of homes
across the United States. In fact, one cow can produce enough manure in one day
to generate 3 kilowatt hours of electricity; the dangers of biogas are mostly
similar to those of natural gas, but with an additional risk from the toxicity
of its hydrogen sulfide fraction. Biogas can be explosive when mixed one part
biogas to 8-20 parts air.
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Biogas from agriculture waste
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Biogas from algae
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New & possible substrates for biogas
production
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Biogas technologies
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Biogas from waste vegetables