Across the globe, countries are taking a stand to make the shift towards becoming more environmentally friendly, and there is growing support for the introduction of bio-fuel as a viable power source. For example, in 2010, a twin-prop plane made the first 100% algal-fuelled flight at a Berlin air show — could this be the future? Together with Suttons, suppliers of lime trees, let’s take a look at the plants that are being tested as bio-fuels, powering a more sustainable future.
What is bio-fuel?
A bio-fuel is a source of energy made from plants. Although researchers are taking more interest in them in recent years, they are not anything new. Henry Ford planned to run his cars on ethanol and early diesel engines were once fuelled by peanut oil. However, once the cheaper alternative of petroleum was discovered, bio-fuel was set aside.
The resultant environmental harm and finite nature of fossil fuels has dominated headlines, as well as the campaign work of researchers and environmentalists — and consequently, focus has returned to renewable energy and bio-fuels. In fact, in 2016, United Airlines announced that they’d be involved with a new initiative to integrate biofuel into its energy supply in a bid to reduce greenhouse gases by 60%.
The term algae relates to large groups or organisms. This ranges from microscopic cyanobacteria to giant kelp, they are typically aquatic and lack stems, roots and leaves. Researchers believe that algae could potentially produce up to 60 times more oil per acre than land-based plants — making it a strong contender for a biofuel provider.
Generating bio-fuel involves breaking down the cell structure of a plant and extracting the oil. Algae is favoured in this respect because it has thin cellulose walls, meaning that less energy is required to break down the structure compared to other plants.
Algae has undergone a breath of tests in recent years, in order to determine whether it could act as a viable energy source. In 2012, Rolls Royce and EADS (now known as Airbus) announced that they were in the planning process of a wind, electricity and algal biofuel-powered plane. They said that this would be built by the year 2033 and produce an astounding 75% less carbon dioxide than the planes that are manufactured today.
An algal covered building can be found in Germany. From its algae surrounding, the building can generate enough biofuel to heat itself and its water supply. The building currently reduces its overall energy needs by 50% and provides natural shading as it absorbs the sunlight. Jan Wurm, a specialist at Arup which was one of the companies behind the algal-covered building project, admitted that upfront costs were high.
Recent research has found that Europe requires a staggering 0.4 billion cubic metres of fuel every year to meet transport demands. To gain this from algae, over 9 million hectares would be required (about the size of Portugal), but scientists are looking at making the process more efficient.
Algae has another beneficial feature supporting its use as a bio-fuel; it needs carbon dioxide to grow. This benefits the environment as it takes CO2 out of the atmosphere — unlike current fuel sources that emit the gas.
More cellulose is found in saplings and grass, and this is the component that is broken down to provide energy — which could indicate that it would be a better option for producing bio-fuels. One of these grasses is switchgrass, a native North American perennial grass (Panicum virgatum).
Cellulose is the structural element of the cell wall of a plant – it’s a stringy fibre that helps the plant to withstand decay. This feature makes it difficult to ferment into ethanol and into an energy source. Cellulosic ethanol is attracting attention as the greenhouse-gas emissions that are produced from this source are thought to be around 86% less than emissions from petroleum sources. This type of ethanol can also be produced from inedible sources such as fallen branches and woodchips — meaning that crops are not being produced for energy generation rather than consumption.
Cellulosic ethanol could be produced using switchgrass, as unlike corn, the cellulose in switchgrass requires less energy from fossil fuels. Scientists have said that switchgrass provides five times as much energy as it takes to grow — an efficient way to create biofuel.
There’s an ongoing debate surrounding the production of biofuels, as some groups maintain the belief that fertile lands should be reserved for food production in line with the booming population of the world. this plant can be grown on acres of land that cannot support crop or food production — addressing this issue.
While we may enjoy looking at sunflowers, we could be using them in a different way — as a potential bio-fuel! The seeds from the flower are rich in oil and according to the National Sunflower Association, 1 acre of sunflowers can produce 600 pounds of oil.
The sunflower has some features in common with other oil crops such as canola and soy – it thrives under a range of conditions and is easy to grow on a small or large scale. The sunflower seed has a high oil content, often over 40%, making it an attractive choice.
A company based on the Hawaiian island of Maui, Pacific Biodiesel, is trialling the effectiveness of the plant as a bio- fuel source of energy. It only takes ninety days for the sunflower to go from ‘soil to oil’ and the plant can be used for a range of purposes; the oil is edible, fuel can be made, the by-product from the extraction process can be used as livestock food and the stalks can be crushed into building material.
However, sunflowers are notably susceptible to diseases and pests, so this will have an impact on the overall effectiveness of the plant as an energy source. Processes such as crop rotation, wider row spacing to encourage air circulation and chemical control can help to manage these issues.
As demonstrated, we are increasingly looking to nature for innovations as we make the shift from conventional, finite energy sources. Of course, there is still research and development to be carried out in order to make the energy generation process more efficient and useable on a wider scale. Who knows what other plants we could discover as biofuel contenders?