Scientists have discovered a new, clean-burning fuel made from unlikely ingredients: coal dust and algae. Coalgae is easy to produce, low in cost, burns without smoke, and researchers believe it can be make a major dent in crude oil imports. It also provides a market for reusing the 50-million to 60-million tonnes of coal dust produced annually as a byproduct of the coal mining industry. This discovery has the potential to save South Africa up to 40 percent of its crude oil imports.
Ben Zeelie and his team at Nelson Mandela Metropolitan University (NMMU) developed a method for producing clean-burning briquettes made from coal dust, which is a waste product of the coal mining industry, and algae. Some 30 percent or so of coal is lost as dust, according to Zeelie, equating to millions of tons each year. The dust is typically buried to prevent it from blowing away and polluting the environment, so finding a way to recycle it into usable fuel, with the help of algae grown in artificial ponds. When the Coalgae briquettes are heated, they produce high-quality crude oil without smoke, behaving completely different than burning coal.
The discovery came quite accidentally. Although the researchers were on a quest to develop a new algae-based fuel, the events that led to the clean-burning briquettes were all happenstance. “The trigger that led us to Coalgae was completely accidental,” says Zeelie. “We were experimenting with growing algae in plastic bags, when we noticed that some of it had leaked out the bags and formed a concentrated algae cake. It got us thinking and we figured that if we bind the algae cake with coal dust, we could come up with a new fuel.”
The team has spent the past five years perfecting the fuel, which has the added benefit of a low cost. Diverting coal dust waste from the mining industry and combining it with the ‘free’ algae that is grown rapidly in artificial ponds results in substantial quantities of a clean and cost-effective fuel – the perfect marriage of nature and science.
Images via NMMU