Algae produce an oil which can then undergo processing to create a useful biofuel.
Experts from around the globe all say the same thing: Biofuels made from plant material are an important alternative to fossil fuels — and algae, in particular, has the potential to be a very efficient producer. The problem is until now there has been no cost-effective method of harvesting and removing water from the algae to process it effectively.
There is now a solution. That is if University of Sheffield Department of Chemical and Process Engineering Professor Will Zimmerman has his way. He and his team developed an inexpensive way of producing microbubbles that can float algae particles to the surface of the water, making harvesting easier, and saving biofuel-producing companies time and money.
“We thought we had solved the major barrier to biofuel companies processing algae to use as fuel when we used microbubbles to grow the algae more densely,” Zimmerman said.
“It turned out, however, that algae biofuels still couldn’t be produced economically, because of the difficulty in harvesting and dewatering the algae. We had to develop a solution to this problem and once again, microbubbles provided a solution.”
Microbubbles are not a foreign concept: Water purification companies use the process to float out impurities, but no one has used it in this context before, partly because previous methods have been very expensive.
The system developed by Professor Zimmerman’s team uses up to 1000 times less energy to produce the microbubbles and, in addition, the cost of installing the Sheffield microbubble system should be much less than existing flotation systems.
The next step in the project is to develop a pilot plant to test the system at an industrial scale. Professor Zimmerman is already working with Tata Steel at their site in Scunthorpe using CO2 from their flue-gas stacks and plans to continue this partnership to test the new system.
“Professor Zimmerman’s microbubble-based technologies are exactly the kind of step-change innovations that we are seeking as a means to address our emissions in the longer term, and we are delighted to have the opportunity to extend our relationship with Will and his team in the next phase of this pioneering research,” said Dr. Bruce Adderley, manager of climate change breakthrough technology at Tata.