Canada: Pond Biofuels has set up a bioreactor pilot plant at St Marys cement plant in St Marys, Ontario. The raw smokestack gas from the cement plant is recycled to grow algae in a third-generation 25,000L bioreactor at the on-site pilot plant. The resulting algae can be used for bio-oil, food, fertiliser and sewage treatment.
The algae consume CO2, NOX and SOX from the smokestack gas. Every 1kg of algae produced prevents 2kg of CO2 from being emitted into the atmosphere. The St Marys Cement Plant produces 720,000t/yr of cement and 540,000t/yr of CO2. Currently, Pond Biofuels only uses a small portion of the total CO2 output.
"We consider ourselves a carbon recycling technology," said Steve Martin, founder of Pond Biofuels.
The algae thrive in light filled, CO2-rich conditions, which are provided in the bioreactor. The light comes from custom-designed red LED lights that flash continuously. The rapid flashing fools the algae into thinking the days are very short, so it grows very fast. "The algae evolve quite quickly; we can get four, five, six generations of algae in a day," said Martin.
Proving the production of algae at commercial scale is important, but the other important part is finding a market for the algae. "Between 10 – 20% of it is oil that be used for producing biodiesel," said Martin. It could also be used a coal replacement, a soil amendment or even animal feed and it can be easily dried using waste heat from the cement plant.
