Biosolids Energy Centre
A purpose built facility dedicated to Christchurch City Council’s biosolids drying facility, turning waste into a safe, treated soil conditioner.
Commissioned: 2010
Capacity: 4.1MW
Annual Energy Supplied: Approx. 40,000GJ/y
Biosolids Energy Centre Wood Fuel Storage
The Christchurch Biosolids Energy Centre (BEC) is on the Christchurch Wastewater Treatment Plant (WWTP) site, next to the Biosolids Drying Facility, in Bromley.
The BEC comprises two hot water boilers; one a 4.1MW wood chip fuelled plant and the other a 4.1MW landfill gas (methane) fired boiler (with diesel fuel backup). The Energy Centre is designed to supply up to 4.1MW of hot water to the biosolids drying plant. The boilers heat a closed-circuit hot water loop, supplying heat to the adjoining bio-solids drying plant heat exchangers to heat air for the drying process.
The wood-fuelled boiler uses seasoned wood chip supplied by Pioneer Energy Renewables. The chip is fed into the boiler via wind spouts onto a fixed grate with a manual ash extraction refractory and water tube furnace. The boiler is designed to burn blends of seasoned, green and dried, chipped wood residues to generate 165ºC at 11BarG hot water.
The landfill gas boiler is designed to burn landfill gas, biogas, diesel or biodiesel to generate 165ºC at 10.5BarG hot water. This is piped, in series with the wood-fired boiler, to ensure it is always on hot stand-by.
The plant was purpose built for the Christchurch City Council (CCC). The plant was commissioned in 2010 and then sold to the Council. The Council, as plant owner, is responsible for all capital renewals or upgrades.
Pioneer is responsible for the delivery of hot water to the bio-solids drying plant, this includes the daily operation and maintenance of the plant and the supply of wood fuel. To ensure the reliable supply of quality, renewable fuel, Pioneer has established a reliable wood fuel supply chain with fuel supply hubs in Canterbury and Otago.
Inside the BEC Boiler House