Back in October, we talked about how scientists had successfully created battery electrodes from harmful algal blooms. Well this time around, a group of researchers from the Nelson Mandela Metropolitan University (NMMU) in South Africa have contrived another incredible energy-oriented application of algae, in the form of a usable fuel. Christened as the Coalgae, the fuel in question combines both algae and coal dust. Interestingly, relating to the latter material, coal dust is a waste material gathered from the mining scope of coal. So in other words, beyond its fuel capacity, the production of Coalgae can potentially reduce the toxic carbon waste in our environment.
According to statistical figures (put forth by the NMMU researchers), almost 30 percent of the mined coal can be lost as dust. This translates to a whopping 50 to 60 million tonnes of coal dust being wasted every year. Furthermore, beyond just numbers, such large quantities of coal dust waste have to be buried, thus further adding to infrastructural costs and depreciation of the environment (given coal’s tendency to emanate acid water and other harmful chemicals into the top soil).
But much of this baleful ambit can be countered by the usage of coal dust for a new product. Hence the Coalgae enters the stage with its briquette-like shape, which when heated up produces a crude oil variety of very high quality. The chemical story behind this entails the super binding capacity of algae with the coal dust. As a result, the bacteria contained within the algae alters the complex structure of coal.
Coming to the manufacturing scope of the Coalgae, the first step pertains to the artificial growing of algae in huge, shallow ponds that are fitted with bio-reactors to generate the slurry composed of microalgae. The gathered algae concentrate is then mixed with the coal dust waste, and the resultant composite is finally formed into dried briquettes. In terms of effectiveness, when these briquettes are heated up to a temperature of 450 degrees Centigrade, they produce “a high-quality crude oil and a solid, clean-burning fuel.” As Prof Ben Zeelie, the leader of the project, made it clear –
When we burn the Coalgae, it burns without smoke — the combustion behaviour is totally different to burning coal. The oil can be processed in a normal oil refinery, while the solid fuel can be used as thermal coal for heat and energy generation. Hence, if we were to convert the 50-million to 60-million tonnes of coal dust waste into Coalgae and heat it, we could produce over 40 % of SA’s crude oil needs, and similar impressive percentage in other coal-producing countries.
He further talked about the potential economic advantage of the Coalgae fuel –
It is a very high-quality oil, like Texan sweet crude, rich in gasoline and aviation fuel components. The price would be more or less the same, but the market would be stable, with significant environmental benefits.
Lastly, after talks of millions in the quantitative scope, the million-dollar question naturally arises – is Coalgae ready to be mass produced? Well the answer is related to the fact that the team is still testing out certain production factors that could improve large-scale manufacturing of this environment friendly fuel. And the good news is, the first steps towards commercialization are being taken, with some firms in United States and China already showing interest in the ‘low carbon’ invention.