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Power up your waste with Biogas.
08Nov

Power up your waste with Biogas.

Biogas is a valuable by-product of the process often referred to as “Waste to Energy” in Australia and is the all-rounder among renewable energy options.

Simple, clean, cost-effective and waste reducing, biogas is a very reliable source of renewable energy.  Only biogas is able to take a waste stream and convert it to electricity, heat and steam – operating 24 hours a day, 7 days a week, whatever the weather (even in Victoria!)

How is biogas produced?

Biogas is produced by means of anaerobic digestion - the microbiological decomposition of organic materials in a humid, oxygen free environment. The biogas plant’s principle of operation is a controlled biological breakdown process (digestion/fermentation) which converts the organic biomass into its separate elements: water, carbon dioxide and methane.

What is biogas composed of?

The end-product is combustible biogas, a mixture that mainly consists of methane (50-75 %), carbon dioxide (25-45 %) and small proportions of water as well as trace gases, such as hydrogen sulphide, oxygen, nitrogen, ammonia and hydrogen.

In simple terms....

We take your waste (Industrial, Agricultural, Food and Manure) - normally a liability - and through the treatment process turn it into fertiliser for the land and gas for use as an energy source to produce electricity or heat.

What is biogas composed of?

Biogas mainly consists of methane (50-75%), carbon dioxide (25-45%), small proportions of water as well as trace gases such as hydrogen sulphide, oxygen, nitrogen, ammonia and hydrogen.

Now for the science....

Organic materials ferment at temperatures between 0 ºC und 70 ºC – in an oxygen free, humid environment - and under the effect of methanogenic bacteria (methanococcus and methanobacterium species). During the digestion process, the carbon in the substrates is converted into biogas in four phases. These four phases are divided into:

  • hydrolysis (first phase)
  • acidification (second phase)
  • acetogenesis (third phase)
  • methanogenesis (fourth phase)

Unlike composting, which represents a rotting process, digestion generates methane gas rather than heat. Neutral carbon dioxide, water and trace gases, such as hydrogen sulphide, ammonia, elementary nitrogen, hydrogen and oxygen, are also generated.

The principle of anaerobic digestion is a natural process, occurring in many environments.  It occurs in sea muds, rivers and lakes, swamps and marshes, unventilated soil layers, landfill sites, slurry and sewage pits or rice farming. Depending on where anaerobic digestion occurs, it is referred to as marsh gas, fermentation gas, sewage gas, mine gas, landfill gas or, in the agricultural sector, biogas.

Biogas as a substitute for natural gas

The methane in biogas is chemically equivalent to natural gas and it is the main energy-bearing component. One cubic meter of biogas with a methane content of 60 % corresponds to an energy value of approx. six kilowatt hours. 

The biogas can be fed directly into a boiler to make steam and replace natural gas or it can be “scrubbed” to remove hydrogen sulphide and fed into a CHP unit and generate electricity and provide thermal heating.  Depending upon the cost of energy (gas or electricity), utility savings are significant and provide a payback period of 3 to 5 years on equipment which will last 10 to 20 years.

Fertilizer from biogas production

The digestate remaining after digestion (biomass and minerals that have not decomposed) has excellent fertiliser properties and can be used on agricultural land.


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