A wastewater treatment process that recycles biodiesel glycerol and produces ‘green’ renewable energy is now underway in Christchurch.
The process, which is the result of three years’ of testing and research between the Christchurch City Council and Solid Energy, is currently being used at the Council’s Wastewater Treatment Plant in Bromley, New Zealand’s second largest wastewater treatment facility.
"Research and testing has confirmed a method which uses the glycerol by-product to supercharge the plant's gas production, delivering much more gas, and therefore energy, than it would normally," says Christchurch City Council City Water and Waste Manager, Mark Christison.
“Without Solid Energy’s help we would not have been able to successfully create a process that is both beneficial to the environment and to the operational sustainability of our wastewater treatment procedures.”
Biodiesel New Zealand Limited [a subsidiary of Solid Energy New Zealand Limited] produces high quality biodiesel from two fuel sources: used vegetable oil (collected from restaurants and food plants), and locally grown oilseed rape crops. The biodiesel glycerol has been an instrumental ingredient in the success of the Council’s renewable energy project.
The glycerol recycling process uses a combination of wastewater sludge from Christchurch City and biodiesel glycerol to produce biomethane gas. The biomethane is being used at the wastewater treatment plant to generate electricity and heat, and there are plans to use the gas created during the process at community facilities such as the Christchurch Art Gallery and Civic Offices.
The project is part of a wider, ongoing collaboration between the Council and Solid Energy to develop resource reuse programs for the Canterbury community.
"This beneficial reuse of a by-product from what is already a sustainable production system is the type of work we look forward to progressing with Solid Energy,” says Mr Christison.