Bubbling Fluidised Bed Boiler technology, New Zealand

Previously, the Silver Fern Farms Ltd meat processing plant at Finegand, New Zealand was highly dependent on fossil fuels.

To achieve a reduction in fossil fuel consumption, Aurecon’s client, Energy for Industry Ltd opted to use a bubbling fluidised bed boiler. This technology burns solid fuels in an air-suspended bed of particles, in this case local river sand.

For its part, Aurecon acted as the technical consultant on the boiler and associated systems and provided technical advice and project management services. This included acting as the engineer’s representative for FIDIC-based Engineering, Procurement and Construction (EPC) contracts and commissioning and performance testing overseeing for the completed plant.

The design saw the delivery of a boiler that is fuelled by a combination of dewatered meat processing plant effluent sludge and wood residues for use in steam production. Separate fuel handling systems can be used for either sludge or wood residues in order to provide maximum flexibility in fuel mixtures.

The environmental benefits are achieved by decreased consumption of a high sulphur content coal and the reduction in particulate emissions from the site through the use of a baghouse filter.

The solution applied in this instance means that an otherwise waste product, with its own odour/air quality and other adverse impacts, is converted into a valuable renewable energy source. By doing so, the client avoided cost penalties under New Zealand’s emission trading scheme regimes.

The completed Silver Fern Farms Ltd project created the potential to generate new bio-fuel sources through the application of this technology in other industries. The boiler process itself was developed collaboratively by Aurecon, Energy for Industry Ltd and Silver Fern Farms Ltd.