Biomass to bioenergy

9 March 2015

Biomass is any recently living plant or animal matter that can converted into liquid (biofuels) or gaseous fuels (biogas) to produce energy.  

There are three common technologies that are used to extract energy from biomass, which is known as bioenergy. Take a moment to explore the options and how they work. 

Direct combustion: burning biomass, such as wood, to produce heat.

This heat can be used directly (to heat a building) or to produce steam to drive a turbine which generates electricity. Both heat and electricity can be used in combination (cogeneration) to maximise efficiency.

When processing sugar, the leftover sugarcane fibre known as ‘bagasse’, fuels the boilers in the sugar mills, which produces steam to generate electricity.

At the same time, sugar mills capture the heat directly from the burning bagasse and use it to help process the sugar.1 Around two thirds of Australia’s bioenergy is sourced from sugarcane waste (bagasse).2 This video shows how sugarcane is used to produce gas for electricity generation.

Bioelectricity Cogeneration

 

Gasification: heating solid biomass, such as agriculture waste (manure and crop reside) and wood waste, to around 800 degrees Celsius in an environment with limited oxygen supply.

Under these conditions, biomass is converted to ‘syngas’, which can be used to power turbines or cogeneration plants.3

Anaerobic digestion: the breakdown of biodegradable material, like manure and wet agricultural residue, such as straw, in the absence of oxygen to produce biogas (mainly methane and carbon dioxide).

Once the carbon dioxide is removed, ‘biomethane’ is the result. This can be used to fuel gas-fired vehicles, as well as for heating and cooling in a similar way to natural gas. This process actually occurs naturally at landfill sites and rubbish tips.

Learn more about the advantages and disadvantages of bioenergy.

  1. Bioenergy Austrlia, Sucrogen: co-generation plants and bioethanol, Bioenergy Australia.
  2. Clean Energy Council 2013, Clean Energy Australia report 2013, Clean Energy Council, Melbourne.
  3. Biogas Australia, Gasification and Pyrolysis, Biogas Australia.