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| CSIRO | SOLVE | Issue 9 | NOV 06 | |
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ARTICLE
SOLID FUELS:
Fuel Solution Out of the Box By Sue Neales
One man's waste is another's treasure on King Island in Bass Strait, where some clever engineering has closed an environmental loopKing Island has two problems – a future shortage of wood and mountains of cardboard. Now a joint effort between its main industries – kelp and dairy – has seen the two problems merge and a possible solution take shape.
John Hiscock, the general manager of Kelp Industries on King Island, recalls the day 16 months ago that a plausible answer was found: "It wasn't like a light bulb popped, it happened slowly, more like a fluorescent light," laughs Mr Hiscock, "…because it evolved as a joint idea within these industries. "The [King Island] dairy had mentioned how much waste cardboard they had and that it was too expensive to ship back to the mainland. They were wondering how they could use it on the island. Then I remembered the briquettes made from cardboard I'd seen for sale in a shop somewhere…" Coincidentally, Kelp Industries was looking for an alternative fuel for drying its seaweed. The wood it has always used to fire its furnaces may be in short supply on the island one day, and importing gas or diesel is too expensive. The kelp industry on the 60-kilometre-long King Island, off the north-west coast of Tasmania, employs 45 of the 1600 locals and earns about $2.5 million a year for the remote economy. Extracts from the dried seaweed are used as thickening agents in food and industrial products worldwide. "So it occurred to me that using this waste cardboard as a fuel source – if it was at all feasible – might solve a few problems for us and the dairy, and maybe for the island as well," Mr Hiscock says. The King Island Dairy (National Foods), which sends three 400-litre bins of waste cardboard packaging to the local tip every week, agreed enthusiastically, as did the King Island Council. Council general manager Andrew Wardlaw says reducing landfill and improving waste recycling is a hot topic for the island, with the old tip full and a new one just opened. The proposal also fitted neatly with the council's commitment to clean, green and sustainable principles, and the island's reputation as a producer of fresh and pure gourmet foods. To turn the idea into reality, CSIRO was approached. That was when the phone first rang in the laboratory of Bob Flann, principal research scientist with CSIRO Minerals in Melbourne. An expert in furnaces and briquetting, Mr Flann relished the challenge to help the King Island community solve its problems – and to neatly close a processing loop. "It was a project from 'left field' with what looked like a natty solution, and I really liked the idea that CSIRO could help the island people in facilitating a good outcome," he says. The first step was to fly to King Island to inspect the furnaces being used by Kelp Industries, and the type of cardboard available. Key scientific elements that CSIRO needed to resolve were the correct density of the cardboard briquettes for use in the furnace, the optimal ratio of cardboard to wood burning to sustain the process, and ash analysis to ensure impurities from the cardboard did not contaminate the drying seaweed.
One year later, after a trial of 300 kilograms of briquettes made by CSIRO Minerals in Melbourne and shipped to Kelp Industries on King Island, the results are scientifically clear. Solid briquettes made from shredded cardboard waste and about the size of a house brick work well in the Kelp Industries furnace as a 30–50 per cent component of the total fuel mix. Extensive analysis established that potential contaminants such as arsenic, lead, cadmium and mercury in the dried seaweed were negligible, although Mr Flann recommends that only plain cardboard with minimal colour is used. A spin-off benefit is that the briquettes are also suitable for home use. "But we're not quite there yet," admits King Island Dairy's environmental coordinator, Steve Newham. "The big question now is who makes the briquettes, who buys the briquette machine (which can cost between $70,000 and $150,000), where we locate the cardboard depot and who operates the facility," he says. Mr Wardlaw says the council supports the concept, "But we are only a small community. It has to make sense financially as well as environmentally and that's what we need to resolve at the moment."For further information contact: |
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