The challenge

Since the Gympie factory began manufacturing instant coffee in 1987 the demand for steam has risen due to increased production, changes to processes and tighter government emission limits.

Nestlé needed a solution to address reliability and capacity issues, and was also interested in maximising the financial and environmental benefits of solid fuel use.

The solution

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Nestlé installed a fluidised bed boiler in the factory with a steam capacity of 24 tonnes per hour, and with a modern electrostatic precipitator fitted in the exhaust stream to remove particulates from the flue gas.

The boiler features an innovative fuel system able to cope with a wet, variable biomass fuel stream and a fluidised bed combustion system tailored for high moisture and finely ground organic materials.

The system uses all of the factory’s spent coffee grounds supplemented with low-cost sawdust sourced from the wastes of regional sawmills.

Environmental impact

The project is expected to save 4,000 tonnes per annum of greenhouse gas emissions. Thermal efficiency of the boiler is now at 75 per cent and particulate emissions are lower than 10 parts per million.

Project success

In addition to reduced emission levels, the Gympie project has resulted in cleaner operations, and 5,400 tonnes less waste to landfill a year.

Gas production has also been reduced due to the ability of the system to restart after eight hours without gas firing.