Algae is a potential renewable fuel source

Ross McGregor
Crucible employee, Ross McGregor, preparing to concentrate an algal culture.

The change to a biofuel economy could be seamless, as long as production and cost can be controlled through technological innovation and appropriate market incentives.

Sugar cane and palm oil plantations geared to the production of ethanol and biodiesel are examples of biofuel industries; however these require large amounts of land, consume significant resources and possibly compete with food crop production.

One environmentally-friendly alternative may be the use of algae to produce biocrude.

A co-operative project involving the NSW Department of Primary Industries, Macquarie and Newcastle Universities and a private company, the Crucible Group, is currently investigating the potential of algal biocrude as a product which offers more than just being a liquid fuel substitute.

Careful harvesting and processing of the algal biomass could significantly displace petro-chemicals, reduce overall greenhouse gas production and recycle organic nutrients.

This resource is also capable of creating next-generation plastics, fertilisers, pesticides and other consumer products, as well as processing for high-grade applications such as aviation grade fuel.

Preference is being given to algal species that can grow in saline or brackish waters or wastewater streams, given the scarcity of fresh water in Australia.

Through a process known as pyrolysis, in which the algae is rapidly heated to 450 - 500 degrees in absence of air, the biomass is converted into gases, charcoal and oil.

The gases can be used to fuel the pyrolysis process, while the charcoal or "biochar" can be applied to soils to significantly improve soil productivity.

The oil can be substituted for fossil fuels.

The research partners are seeking to:

  • determine the factors affecting growth of biomass and oil yield from algae for biocrude production
  • map the risks and opportunities relating to various algae growth and cultivation methods
  • investigate the number of petrochemical substitutes that could be produced through commercial cultivation of select algae species in Australia
  • identify methods to optimise energy conversion and recovery throughout the production process
  • assess the applications for algal biocrude in Australia, and
  • identify clear innovation and engineering pathways for sustainable algal biomass production.

NSW Department of Primary Industries’ contribution is in the form of expertise in algal culture.

The department has also conducted extensive research into the agricultural and environmental advantages arising from the use of the pyrolysis by-product, "biochar".