Scientists searching for alternative fuel sources have discovered a surprising solution: seaweed!
That’s right, the largest seaweed in the world, commonly known as kelp, can actually be used to fill up the gas tanks of cars, planes, ships and trucks!
Chemical engineers follow the age-old tradition of drying and washing kelp and then transforming it into biofuel through a process called thermochemical liquefaction. In other words, the kelp is burnt at searing temperatures and high pressure to convert it into bio-based fuels that can be blended into gasoline. The advent of biofuels is one of the contributing factors to humanity’s solution in overcoming our dependence on fossil fuels. In Brazil, more than 80% of light vehicles can run on pure biofuel made from sugarcane, reducing up to 90% of greenhouse gas emissions compared to fossil fuels. Sweet!
The wonders of kelp
Contrary to current land-based energy crops, such as maize and grains, you don’t need agricultural land, fresh water or artificial fertiliser to cultivate kelp. There’s another point in its favour – ocean-farming kelp doesn’t encroach on rare biodiverse habitats when marginal land is brought into cultivation.
What’s more, the wonderful biology of these giant marine algae also renders them extremely biofuel-friendly.
Being a protist rather than a plant, it’s much simpler to convert kelp into biofuels due to its lack of lignin, the rigid substance that makes land plants woody. Good ol’ algae are also powerhouses for the climate – they trap carbon dioxide, elevate oceanic pH and oxygen levels, and decrease the extent of ocean acidification. Globally, seaweeds could sequester nearly 200 million tonnes of carbon dioxide each year – as much as New York State’s annual emissions! At the end of their life cycle, they drift down to the deep oceans, bringing along much of the carbon they locked up.
As if that’s not impressive enough, the giant kelp (Macrocystis pyrifera) grows at a remarkable rate – 60 cm (24 inches) a day – and constantly forms new fronds, which allows the harvesting of mature fronds up to 45 metres (150 feet) in length.
The superpowers of kelp can only manifest when it’s present in its ideal comfort zone. To grow at such rates, the kelp farm must be exposed to an abundance of sunlight and nutrients. Here’s where things get tricky. Build your farm at the ocean’s sunlit layers, and your kelp won’t get enough nutrients that support its rapid growth. On the other hand, building your farm in deeper waters that are rich in nutrients means your kelp won’t get adequate sunlight.
Taking kelp to a whole new level
Fortunately, a diverse research team of biologists, oceanographers and engineers from USC Wrigley Institute and Marine BioEnergy Inc. came out with an ingenious solution, making it possible to accelerate the growth of kelp. Their study demonstrated the potential of growing it on a large-scale. This is a huge deal as it catapults kelp as a serious frontrunner to become a sustainable and cost-effective source of renewable biofuel.
How did they achieve this? By building an underwater elevator.
Using an open ocean structure powered by the sun, the scientists raised and lowered the kelp farm daily between deep and shallow water. This method known as “depth-cycling” enabled them to grow kelp four times faster than natural beds, proving it to be a biologically viable cultivation strategy.
Their success means that we are one step closer to weaning ourselves off fossil fuels. However, the team will still need to carry out further research to optimise the whole system, as well as address any potential shortcomings. Through it all, they remain cautiously optimistic.
But for now, there’s one thing we can say for sure: Kelp is here to help.
Welp! that’s enough wordplay for the day.
