Dairy producer Woodlands Dairy has commissioned a second biomass boiler that will use local sawdust and chip timber waste for steam generation, which will further reduce the company's heavy fuel oil (HFO) use by about 31% and its emissions by about 1 046 t of carbon dioxide-equivalent a year.

This is the second biomass boiler to be commissioned by Woodlands in its drive to increase the use of renewable energy sources and reduce emissions.

The boiler, nicknamed Bessie, is producing steam and the team has ironed out standard commissioning issues. The aim is to generate a baseload of steam to mitigate the risk of disruption to operations when a steam plant fails, says sustainability manager André Adendorff.

The new John Thompson boiler is rated at 12 t/h at 24-bar pressure. It has a fully automatic control panel, as well as grid collector and stack to manage emissions. It has a dedicated fuel bin, but the two fuel bins can feed either one of the boilers to provide flexibility.

The new furnace can burn bark, which will allow the mill to harvest biomass from within the plantation, if required. The boiler will further allow for statutory inspections and maintenance on the first boiler and vice versa.

The biomass fuel, which consists of wet sawdust and chip timber waste, will be sourced from local timber company MTO, which is within 70 km of the Woodlands site.

“Sourcing local renewable biomass reduces the emissions caused by transportation of the biomass. It also ensures working opportunities for the local labour force, generating economic growth for the community,” Adendorff said.

Meanwhile, the company's first biomass boiler was commissioned in 2016 with the main objective to reduce HFO and electricity use to generate steam for the plant.

“By changing over to a biomass boiler, we reduced our electric-boiler consumption by 40% and our HFO consumption by 83%.

“The second biomass boiler will further reduce our HFO use by about 31%, and result in an increase in biomass use of about 10.7%,” he noted.