Hot recycling helps to cement a future

Hot recycling helps to cement a future
Published: 22 June 2009


Industrial waste has long been a problem for the companies that produce it as well as the broad community, but one firm has taken the view that waste can be an asset, if the right thinking is applied to the problem. Geocycle, located in Dandenong on the fringe of Melbourne, has emerged as the key player in the area and a potential signpost for the future.

The company, a subsidiary of Cement Australia, sees its role as waste transformation, with potentially hazardous materials being turned into alternative fuel and raw materials for use by the cement industry.

The wastes and by-products that are treated at its facility include petroleum products, such as used oils, greases and distillation residues; resins; paints; inks and solvent-based materials; and chemicals such as pesticides and herbicides.

Aluminium smelting residues are also managed by Geocycle for their fuel and raw material content.

"The feedstock comes from a range of industries, as well as through some government collection schemes, and from all over the country,’’ says Stuart Ritchie, national sustainability manager of Cement Australia.

"The economics of paying Geocycle to collect the material is improving as various state government authorities increase charges and fees to dispose of it in traditional ways, and generally toughen their rules about waste disposal.

"At the other end of the treatment process, Geocycle (sells]) the treated product to be used as fuel and as materials for use in the manufacture of cement. So there is both a reduction in the amount of fossil fuels used and a reduction in the amount of material that would otherwise go to landfill.’’

The key to the process is the very high temperatures used in the treatment process, more than 1800°C. Any organics present are decomposed and converted to energy in the combustion process, and inorganic components constitute a raw material for the formation of cement clinker.

"This process would not be suitable in, say, a power station, which uses much lower temperatures,’’ Ritchie says.

"You would be left with an ash (that) could be potentially harmful.

"We are very aware that there is a lot of a variety in waste materials. The Geocycle facility includes a purpose-built lab (that) analyses pre-shipment samples from our customers to determine the suitability of their waste and by-products for treatment. We see the sharing of information as part of providing a ’cradle to grave’ solution (that) is commercially useful for partners while also being ecologically sustainable.’’

Geocycle recently expanded its capacity with the addition of a "megablender’’ capable of processing a much broader range of materials. The project was undertaken with the help of the Australian Sustainable Industry Research Centre and one of Cement Australia’s shareholders, Holcim, and combined technologies from processing industries across the world.

Another advantage of the new equipment is that it removes more water as part of the treatment process, so the resulting fuels have a higher energy content.

"This puts Geocycle at the forefront of technology in this field, compared to other waste processors around the world,’’ says Ritchie. "In the next two years we hope to be able to manufacture a diesel-like distillate (that) can be used as an industrial fuel, and that would really add another dimension to the waste transformation concept.’’

Ritchie acknowledges that the economics of Geocycle’s supply chain are finely balanced, with the transport of waste material, which requires sealed tankers and trucks, remaining a tricky financial issue. Nevertheless, he sees waste transformation as a growth business.

"We are looking at steady development, as more manufacturers become aware of the business advantages,’’ Ritchie says.

There has been long-term monitoring of cement products that incorporate material treated in this way for safety reasons, in Australia and overseas, and there has been no evidence of any problems. Although the technology has advanced in the past few years, the basic concept has been used for about 30 years in other countries. Ritchie says Geocycle has long worked closely with regulatory authorities, especially Victoria’s Environmental Protection Authority.

"We appreciate that regulators have an important job to do,’’ Ritchie says.

"There are still some who have an attitude rooted in the old idea of public health regulation and when they look at industrial waste they see danger rather than a resource. But there is an emerging generation who have a greater willingness to consider innovative solutions to environmental problems. And we see this as being a business about innovative solutions.’’