The Technology
Aquaflow brings a unique and innovative solution focussed on building scalable production systems at site.
Harvesting of Existing Wild Microalgae
Aquaflow has been harvesting algae successfully from sewage ponds for almost two years now and has done so in every season, and even in winter air temperatures of below zero. There are many species of algae occurring naturally here, the advantage of this is that the populations rise and fall; as the environment changes and one species declines another takes its place. This makes the algae population more robust as the system is not prone to total loss if one more species competes for nutrition more successfully (a risk in culturing single algae species).
Our approach is to utilize existing open pond municipal waste facilities where wild micro algae naturally exist. The ponds provide a large surface area for the algae to use sunlight for photosynthesis and also provide the essential nutrients of nitrogen and phosphorous for the algae to grow. The algae also remove (or sequester) carbon from the atmosphere and release oxygen from their photosynthetic activity.
An example of a site suitable for our system is the Marlborough sewage ponds. The details are:
- 60ha of open oxidation ponds.
- Serving a population of 27,000 with a mix of municipal and agro-industrial waste, including a significant wine industry.
- Annual water flow of 5 billion litres.
The microalgae are suspended in the pond water and harvesting them is achieved by pumping the pond water through the Aquaflow harvesting Unit. The harvester achieves 70 - 90% recovery of suspended 
algae biomass material on a continuous basis. The harvest operation is largely automated, requiring minimal staff to oversee multiple harvesters. Our current pilot system is capable of processing 70 cubic metres of algae laden water per hour.
The harvesters are each built inside a 40 foot container, with readily available components that require a low power supply for operation. This allows the harvesters to be easily transported and, if required, taken to remote locations. Multiple container based units can be deployed depending on the site water remediation volume requirements.
Each part of the Aquaflow system is designed to be capable of being used in a complementary way with other technologies. This means the algae harvesting system could be used to harvest algae grown in other ways, and the conversion process (mentioned below) could potentially be used with other feedstock materials, such as digester sludge or other biomass.
Remediation of Water and Upgrading Water Quality
The process of removing the algae from the ponds starts the process of cleaning the water, and we can take that process further - to creating reusable water. Cleaning polluted water becomes a major part of what Aquaflow can and does do.
Excellent progress has been made in the field of harvesting wild microalgae from the outflow of sewage ponds. Aquaflow has been harvesting of tonnes of wild algae from its current operating facility since the beginning of 2008, and the system has been proven to operate well, even in New Zealand's South Island winters when the temperatures can be below zero (Celsius). Operations continue to be tailored and optimised, and provide the essential raw materials for the development programme and for customer evaluation and trial samples.
Conversion of Algae into Green Crude
The other part of the Aquaflow process is the conversion of algae into a crude raw material. This material can then be further refined in the proprietary converstion process at Nelson.
Aquaflow's chemistry development programme runs in parallel with the process and plant development. It provides innovation impetus and continually reviews the status of the conversion technology. A number of other interesting potential products, including bio-derived chemicals, have been identified.
Refining of Green Crude into Bio Derived Fuels and Chemicals
Aquaflow has been working closely with UOP, a Honeywell Corporation in the US, to look at refining the green crude. UOP is the world's foremost refining technology company. Aquaflow is the only compnay in the world to have supplied UOP with any quantity of algae oil from wild algae. This oil has been refined into dies
el and jet fractions.
Further work is being done on our green crude material to enable it to be refined directly into kerosene, diesel and petroleum fractions.
Aquaflow has taken steps to secure IP around other chemicals that are formed in the process that have been identified in the crude mixture. More research and development work is required to separate these materials, purify them and establish their economic viability, but some of their potential applications are as specialty industry solvents, pre-cursors for polymer manufacture, surfactants (detergents) and pharmaceutical components.
Almost every month since the public became aware of Aquaflow's existence another opportunity has been brought to us to respond to. This pattern may well continue into the future, especially in the chemicals and fuels production areas, and we look forward to dealing with those challenges.
