“The reality is that no one in the world has done anything on this scale. Our trial aims to show that this complete process can be cost-effective and efficient”, says NIWA scientist Dr Rupert Craggs. Twelve years of research by NIWA’s Aquatic Pollution Group has culminated in the world’s first large-scale trial of the production of algal bio-crude oil from wastewater.
The commercial feasibility of producing bio-crude oil from algae grown in wastewater is being tested at Christchurch’s wastewater treatment plant. Five hectares of ponds have been converted to so-called ‘high rate algal ponds’. Carbon dioxide is added to the ponds to enhance wastewater treatment and promote algal growth, a technique pioneered by the NIWA group. Gentle mixing with paddle wheels stimulates algal growth and assists with disinfection of the wastewater by sunlight.
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NIWA's research site at the Christchurch wasterwater treatment plant. (NIWA)
The algal biomass harvested from the ponds is converted into bio-oil using super critical water reactor (SCWR) technology, developed by Christchurch company, Solray Energy. The technology uses heat and pressure to convert biomass sources into crude bio-oil. NIWA’s study will determine the energy efficiency and economics of this process at large-scale including the co-benefits of (i) recovery of wastewater nutrients for fertiliser, and (ii) greenhouse gas abatement through low-energy wastewater treatment and off-set fossil fuel use. Dr Craggs is leading the Foundation for Research, Science and Technology-funded project. “By demonstrating that conventional wastewater treatment ponds can be upgraded with low-cost, energy efficient enhanced ponds, we aim to prove that algal biofuel production is commercially viable today.”
Read about the bio-crude oil project in more detail.
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NIWA CEO John Morgan, project leader Dr Rupert Craggs, and Energy Minister Hon Gerry Brownlee, with crude and refined bio-oil made from algae. The oil is processed by Solray Energy Ltd, NIWA's collaborators in the project. (NIWA)
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A lawnmower is fuelled with bio-oil manufactured from algae at the research site in Christchurch. (NIWA)
Contact: Dr Rupert Craggs, NIWA