The possibility of a domestic biomass supply chain would also be investigated, Hickman said. The companies had signed a biomass collaboration agreement as they looked for an alternative fuel source to help decarbonise the businesses, she said. The agreement came ahead of a trial to burn biomass at Genesis’ Huntly Power Station this week, Hickman said.
Genesis burned coal to generate electricity, while Fonterra burned coal to create heat for dairy processing. The Huntly plant would continue to provide back-up to the electricity grid while Genesis transitioned to more renewable generating methods, she said. The biomass used in the trial was imported and not manufactured locally, she said.
The black torrefied biomass was made from tree sawdust. During torrefaction the biomass was heated slowly without oxygen to between 200C to 300C, she said. The process created a solid and uniform pellets that had about 30% more energy than raw biomass, Hickman said. Burned torrefied biomass generally produced less than 10% of the emissions of coal, she said.
If the trial was successful the companies wanted to use New Zealand wood residues, including forestry slash, to produce biomass, Hickman said. The companies needed to work with the forestry sector to determine how it could create a constant supply of raw material, and the possibility of a biomass plant being built, she said.