It may not smell like roses, but it could become a great sustainability love story. Solray Energy of New Zealand has found a way to turn sewage into biofuel. At what they call the world’s largest algae refinery and their business is quite possibly the holy grail of green alchemy: they convert toilet wastewater to biofuel. Launching their “Algae to Oil Conversion Technology” this week, the joint venture company combines the chemical engineering of Solvent Rescue with the Mechanical Engineering of Rayners, two New Zealand based companies.
The multi-million dollar project is essentially a network of wastewater ponds that grow algae, fed by CO2 from the plant grows algae in shallow wastewater ponds, fed by carbon dioxide generated from the nearby Christchurch Wastewater Treatment Plant and good old, natural sunshine.
From there, algae is harvested and sent to Solray, where it is routed through reaction tubes under pressure of 6,000 psi and 400 degree C heat. What comes out the other side is something they call “biocrude,” and it can be turned into oil, petrol, diesel, kerosene or bitumen.
The project serves as a functioning model that supports new technology with a combination of funding from both government and private sources, with NZ$1.5m coming from Solray, and the rest coming from government-backed NZ$2.5m grant from Foundation for Research, Science and Technology, and NZ$500,000 from the National Institute of Water and Atmospheric Research (NIWA).
At the opening of the new plant, New Zealand Energy Minister Gerry Brownlee used a form of the fuel, to run a lawnmower- somewhat ironic, but impressive nonetheless.
The idea of a community creating fuel from its own sewage is seductive from a sustainability perspective. The drawback is that even at this plant, the actual biocrude output is just a fraction of local energy needs- 550 barrels of crude oil annually. Officials say that if all of the sewage ponds in Christchurch were used to create biocrude they could only produce enough to cover 15% of the city’s yearly gas use.
Still, this technology is impressive and the first of its kind, and it is promising for smaller- or medium-sized communities, according to Rupert Craggs, a NIWA scientist. And as the world looks for an arsenal of solutions to reduce energy use and increase production from sustainable and renewable sources, it is a promising way to look at things in a new light- as they say, one man’s trash is another man’s treasure. In this case, one town’s sewage could become another town’s fuel.