Cane harvest setback for 'green' sugar

The smoky haze of North Coast cane fires has returned and NSW’s much-vaunted green cane harvesting has been abandoned until technology can be developed to process the tough-fibred cane plant with better sugar recovery.

After two years of struggling with breakdowns and processing hiccups, the NSW sugar industry’s world-first attempt to send the entire unburnt cane crop to the sugar mill, and then use the waste to fuel for its cutting-edge electricity cogeneration plants, has been halted.

The 2009 cane harvest has wrapped up with producers across all three NSW cane growing regions, on the Tweed, Richmond and Clarence Rivers, reverting to burning.

Apart from trials, no cane will be cut green in 2010.

In much of Queensland cane is harvested unburnt with the trash left as a soil mulch cover, but nowhere else in the world had an attempt been made to cut whole-of-cane and send it to the mill.

NSW Canegrowers chairman, Vince Castle, said present science simply did not allow for better sugar recovery levels in the processing of whole-of-cane.

The amount of trash and hardened growth in two-year-old cane harvested in NSW was simply too much for the equipment to cope with.

He said the failure (to date) of the mammoth green harvesting attempt was “extremely disappointing” to growers and contract harvesters, who had spent millions of dollars modifying equipment to no gain and would now be wearing that debt.

NSW Sugar Milling Co-operative chief executive officer, Chris Connors, said all possible resources were being utilised in an effort to come up with the solution and he predicted an answer within two years.

“Some changes to processing within the factory may be possible to achieve better recovery, but alternatives are being investigated, such as bringing whole cane to the factory but not processing it,” he said.

“That could involve installing a cleaning plant. Engineers have been engaged to develop a suitable design.

“Options to deal with trash at the harvester are also being investigated, such as a redesigned extractor that chops the trash, but not the cane, into shorter pieces and delivers it to the harvester elevator.

“Vibrating the cane in the bulk transport bins to achieve greater bulk load densities and reduce transport volumes and costs is also under investigation.”

About $500,000 had been allocated by the Sugar Research and Development Corporation for this work and the co-op had employed an agricultural engineer to work on the problem.

In the meantime, alternative fuels, such as timber mill residues and camphor laurel trees, were in strong supply to feed the electricity generator.

With crushing due to finish this month, cane tonnage for 2009 has been a disappointing 1.7 million, down from last year’s 1.9m and much lower than record years of more than 2.6m.

A dry summer and four-month winter dry affected yields, slashing production by more than 400,000 tonnes from early estimates.

However, high sugar content levels – up to 25 per cent above those of the past two to five years – have helped bridge the yield gap.

source: nqr.farmonline