Biomass is biological material derived from living or recently living organisms and includes tree and food crop residues, animal effluent and offal. Bioenergy is a form of renewable energy derived from biomass to generate electricity and heat or to produce liquid fuels for transport.
As an example of the value of the resources available, 1 tonne of cereal straw can be converted into about 300 litres of ethanol biofuel or up to 3300 kilowatt hours of heat energy.
Producers can add to their income and/or reduce running costs by using low value agricultural wastes to produce biofuels. Biofuels can be used to produce heat and electricity within the business, thereby reducing costs, or selling these products or their wastes to other bioenergy producers.
Some of the processes used to create biofuel also produce secondary products, such as fertilisers and biochar, that can be used directly or sold.
Technologies for using biomass
The department has published a report (Biomass scoping study: opportunities for agriculture in Western Australia - Bulletin 4862) outlining the 3 main technologies used around the world to produce high value products from low value waste resulting from production systems.
These technologies are:
- combustion, gasification and pyrolysis
- second generation ethanol production
- anaerobic digestion.
The report outlines selected projects from around Australia and the world that are developing new industries based on biomass waste. The report also provides information on feedstock availability, potential customers for the energy produced and barriers to uptake.
Businesses using biomass in Western Australia
There are a number of businesses producing bioenergy in WA (as at November 2015):
- Richgro garden products in Jandakot, just south of Perth, have installed an anaerobic digester that converts 100 tonnes of food waste per day into biogas. They use this biogas to supply all of their electricity and heating needs and also use the carbon dioxide generated to increase production in their greenhouses.
- At the smaller end of the scale, Fairbrossen Winery in the Perth foothills crushes 50 tonnes of grapes per year and has started using the leftover skins and seeds (grape marc) to feed a small anaerobic digestion unit. Fairbrossen uses the biogas for cooking in their restaurant and to augment the electricity generated from their solar panels.
- Morton Seed and Grain in Wagin process oats for the local and international breakfast cereal markets. They have replaced their gas and electricity power supplies with a bioenergy unit that produces all the heat and power they need using the oat husks as a fuel source. The biomass boiler is now being used to generate the steam required for the grain processing and the electricity generation turbine is installed and operational. Electricity export to the grid began in October 2015.
- Macco Feeds in Williams have replaced their gas-fired boiler with a wood-fired boiler to supply the heat and steam they need to make their products. They use up to 4000 tonnes of mallee and plantation grown woodchips per year and generate up to 1.7 megawatts of energy. The switch has resulted in an energy cost saving of 80%, and uses a local, reliable and sustainable source of fuel.
- Plantation Energy Australia (PEA) will soon start re-manufacturing and exporting densified wood pellets (Figure 1) from the Albany port to Asian markets where they will be used for generating heat and electricity. The pellets are made from plantation timber and PEA expect to ship up to 250 000 tonnes of pellets per year.
Ansac (a Western Australian engineering company) in partnership with the East Metropolitan Regional Councils (EMRC) have recently announced their intention to build a 3 megawatt electricity generation facility in Hazelmere fuelled by waste wood (Figure 2).
EMRC will provide wood such as old pallets that have been diverted from landfill as feedstock and this will be chipped and fed into a pyrolysis chamber that will convert the wood into syngas. This gas will be cleaned and used to power a bank of generators that will produce the electricity.
The final cost of the electricity produced will be 10–14 cents per kilowatt hour. The facility will create up to 20 new jobs in the construction phase and then require 2–3 full time employees once in production. To begin with it will operate for 10 hours a day and consume 33 tonnes of wood waste a day.
This kind of facility is now economically viable anywhere there is a reliable supply of woody biomass and an electricity user.
Construction is underway and Ansac expect to begin commissioning in July 2016.
Potential for biomass in WA
About 7 million tonnes of cereal straw are produced every year in WA (Table 1): this product has significant commercial potential.
An ethanol plant – of the type built in Crescentino in northern Italy – could convert 220 000 tonnes of straw into 40 000 tonnes of ethanol.
Biomass types are varied and are intrinsically linked to the size, scale and productive capacity of the various industries. In WA, the cropping industry produces the largest amount of waste biomass, with dairy, plantation forestry, and other industries also producing substantial amounts of biomass, often in point source locations.
|Biomass type||Tonnes per year|
|Cereal straw||6 930 000|
|Dairy effluent (wet weight)||2 313 000|
|Hardwood residues||1 186 000|
|Softwood residues||371 000|
|Grape marc||20 200|
|Cattle feedlots||19 500|
|Broiler litter (wet weight)||19 300|
Industries, such as poultry farms, dairies and piggeries, have potential to significantly reduce their costs and deal with problem biomass wastes on-site because they have a high energy demand and produce significant amounts of secondary biomass.
There is also potential to aggregate biomass at a state level and match these with areas of high energy demand.
The Department of Primary Industries and Regional Development (DPIRD) has mapped biomass available to new industry development as part of the Australian Biomass for Bioenergy Assessment, and that data is now available on the Australian Renewable energy Mapping Interface (AREMI). For more information, contact Kim Brooksbank or Ron Master.