Biomass for energy or biofuels

The Bioenergy Australia conference which was held on the Gold Coast in November showcased some of the most advanced and innovative bioenergy technologies being developed from around the world.

The two day conference included over 100 presentations focused on policies, programs and commercial case studies across a variety of feedstocks and technologies used to convert biomass to energy or biofuels. Key topic streams this year included bioenergy production from waste, algae and biogas, as well as exploring issues such as supply logistics, water management and cogeneration.

Colin Stucley, CEO of the Renewable Oil Corporation (ROC), presented on the company’s work to develop a sustainable aviation biofuel as part of a consortium which includes Virgin Airlines, GE, Dynamotive Energy Systems Corporation and Future Farm Industries Co-operative Research Centre.

Claimed as a world first, the consortium plans to use innovative fast pyrolysis technology to process mallees, a eucalypt tree that can be grown sustainably in many parts of Australia. Suitable land for growing mallees extends across much of southern Australian. Already more than 1000 farmers have planted mallees in belts on their farms, mainly in Western Australia. The mallees have also been used over the past 15 years to help with dryland salinity management.

Mallees are favoured because they are highly effective at using nearly all the rain that falls and at drawing down groundwater, thus preventing salt rising to and accumulating at the land surface. When the mallees are grown across crop and pasture paddocks other benefits can be achieved including: windbreaks to prevent soil erosion; food and shelter for native fauna resident in nearby trees and remnant bush; and carbon sequestration that helps offset greenhouse gas emissions.

Biofuels processed from mallee biomass are called ‘second-generation biofuels’ and are derived from the breakdown of lignins and cellulose which are not digestible by humans. This avoids the use of grain, corn, sugar and oilseed crops (first-generation biofuels).

Fast pyrolysis is an established process that converts many forms of biomass into a crude oil (bio-oil) along with char and gas. The char is a useful by-product, either as a reductant in metallurgical processing or for soil amelioration (called bio-char). The bio-oil is upgraded in a second refining process to produce diesel, aviation fuel and petrol.

The sustainable aviation biofuel consortium brings together companies with special expertise in growing, harvesting and processing feedstock into aviation fuel. The team is currently finalising plans for a demonstration unit that will make bio-fuels for testing, certification and public trials. The pilot biofuel production unit will be built in 2012, followed by the construction of a commercial-scale plant, which could be operational as early as 2014.

A recent CSIRO report estimated that the aviation industry could cut greenhouse gas emissions by 17%, generate more than 12,000 jobs and reduce Australia’s reliance on aviation fuel imports by $2 billion per annum over the next 20 years through the adoption of biofuels.

Colin Stucley said: “This consortium has great potential. It offers world-class biofuel technology and a unique Australian feedstock. We are excited about supplying Virgin and GE with commercial quantities of the new biofuel and building this new business.”

The Bioenergy conference also conducted technical tours of operational bioenergy technologies within Queensland including:

• The AGL bioelectricity plant that produces enough energy from macadamia nut shells to power its entire manufacturing and processing activity;
• A fluidised bed combustor, providing process bioheat at a Nestlé coffee factory;
• An organic rankine cycle energy system at Gympie Timber Company’s timber mill;
• BTOLA’s napier grass energy cropping; and
• A pongamia plantation developing an alternative feedstock for biofuels’ production.