Capturing gas makes good of a bad by-product

Weekend Australian
Saturday 31/5/2008 Page: 4

THIS month enough clean energy to power 5000 homes was commissioned at Sydney's Eastern Creek waste management facility. Five 1.1MW engines which convert greenhouse gases escaping from landfill at Eastern Creek into power that can be sold on to the national grid were switched on.

When we think clean energy, images of pristine Australian landscapes dotted, with glimmering solar cells, resplendent windmills or the dramatic beauty of a hydro-electric power station spring to mind. But a vital and significant contribution to clean energy production comes from reprocessing degradable household and commercial waste.

It is a vital contribution, because the landfill gas captured to make this electricity is up to 60 per cent methane. And methane gas has a global warming potential 25 times more damaging to the environment than carbon dioxide, according to a report prepared for the Total Environment Centre in 2007. Left to leak unchecked into the atmosphere, landfill gases account for more than 3 per cent of Australia's carbon emissions. By 2050 when emissions targets have been introduced, landfill gas will account for 20 per cent of our national carbon budget - or up to 80 per cent, depending on the targets agreed.

What is more, every tonne of degradable waste material - food scraps, wood, paper, garden waste = sent to landfill today will still be producing harmful greenhouse gases in 2050. It is a significant contribution because, according to figures from the Clean Energy Council, energy production from methane gas collected at landfill sites around Australia currently has the capacity to provide baseload electricity to power as many as 128,000 Australian households.

The Eastern Creek initiative is a joint venture between LBS Generation Pty Ltd and WSN Environmental Services, a company owned by the "NSW State Government but incorporated in 2001. Phase two of the project, due to complete in 2014, will see. another 1.1MW engine brought online.

According to CEO Ken Kanofski, converting these gases into energy that can be sold at a profit is sound commercial practice and an appropriate response to a changing market in waste management. "Right now, energy and sales of anything else recoverable from the waste process accounts for up to 10 per cent of our income, but this is changing", says Kanofski, who believes that the industry will shift its dependence on the fee councils pay to have their waste removed, to earnings from the sale of whatever can be recovered, recycled or processed into something new.

Energy is one of these recoverables, and in a carbon restricted economy, clean energy is set to become an increasingly valuable. commodity. "Once, we sold the right to extract landfill gas to third parties. Now we are looking at taking a more direct and active role in energy. production as it becomes a more core part of our business", says Kanofski. The collection of methane gas from existing landfill is a commercial activity with limited timeframe, however.

International approaches to waste management include a complete banning of putrescible wastes (the ones that rot down and release methane) in landfill in Europe, and in Australia state governments are increasingly seeing landfill as a waste-management solution of last resort. The longer-term vision must be to decrease the amount of landfill and to process the waste in a different manner, says Kanofski.

With this in mind, WSN Environmental Services has developed two alternative-waste technology plants in the greater Sydney region, including the Macarthur Resource Recovery Park to open this year. This $50 million facility at Lacks Gully in Sydney's south-west will process the waste of four area councils: Campbelltown, Camden, Wollondilly and Wingecarribee under a 15-year contractual arrangement.

Gas capture and energy production will be part of the plant's remit The Macarthur Resource Recovery Park will use anaerobic digestion, which is the biological breakdown of carbon active materials in the absence of oxygen. The proprietary process selected by WSN has been developed by an Israeli company, ArrowBio. It includes the sorting of waste, the removal of recyclable materials, and then the anaerobic digestion of any carbon active material in an enclosed system.

WSN projects that within a year of operation the Macarthur Resource Recovery Park will be producing enough energy to power 2500 homes a year, and stop up to, 23,000 tonnes of greenhouse, gas emissions annually. Macarthur Resource Recovery Park will be WSN's second alternative waste management facility, and the second anaerobic digestor in operation in Australia..

The first, UR-3R (Urban Resources Reduction, Recovery and Recycling) a joint venture with Global Renewables at Eastern Creek also owned by WSN, was established in 2004. Anaerobic digestion of waste products to produce fuel is not unique to WSN facilities. Visy Pulp and Paper produces' biogas waste from its paper making plant at Gibson Island, Queensland. This is converted to clean energy and used directly to power part of its plant.