liquid simplicity

World’s largest wastewater algae to bio-crude oil demonstration puts CO2 to good use.

retrieved from http://algae2oil.blogspot.com/2009/12/worlds-largest-wastewater-algae-to-bio.html
This week will see the Minister of Energy Hon Gerry Brownlee open the largest wastewater algae to bio-crude oil demonstration project in the world.

The project combines NIWA’s scientific expertise on advanced wastewater treatment and algal production pond technology with Solray’s bio-crude oil conversion technology and is hosted by Christchurch City Council at the Christchurch Wastewater Treatment Plant.

“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 pioneering NIWA Algal Pond Scientist, Dr Rupert Craggs. The process creates value at every step – it treats wastewater, recovers wastewater nutrients as fertiliser, removes carbon dioxide from flue gas, and creates biofuel.
The Christchurch wastewater treatment plant has 230 hectares of polishing ponds that are currently used to provide disinfection of the treated wastewater prior to discharge. It is in one of these ponds that five hectares have been cordoned off by NIWA and converted into a series of specially designed High Rate Algal Ponds with carbon dioxide (CO2) addition.

“Adding CO2 into the ponds enhances wastewater treatment and doubles algal production – biofuel production could be a great co-benefit for the community from its wastewater treatment” says Dr Craggs.

Another advantage of High Rate Algal Ponds is that the algae growing in these systems can be easily harvested by simple gravity settling – the harvested algal biomass can then be used as either a fertiliser or feed for livestock and aquaculture, or, as is this case with this demonstration, be converted to biofuel and the residue used as fertiliser.

The algae is collected from the harvesters and pumped to Solray’s specially designed “Super Critical Water Reactor” where pressure and heat converts it to bio-crude oil. The bio-crude, like fossil crude oil, can then be refined into LPG, petrol, kerosene, diesel, bitumen, and other oil based products.
“This process is essentially the same as nature used many millions of years ago to create the oilfields of the world we are currently rapidly depleting” says Chris Bathurst, Solray Energy Ltd.

This trial is the culmination of over twelve years of research into High Rate Algal Pond wastewater treatment by NIWA and will demonstrate the commercial feasibility of algal biofuel production from these advanced wastewater treatment ponds which are a cost-effective way to upgrade the oxidation ponds currently used to treat the wastewater from many New Zealand communities.