Not only is sugarcane is the main source of the world’s sugar, it’s now also an important source of energy.
Grown widely in the tropics and sub-tropical regions, sugarcane is turned into bio-fuels and bio-based materials, which can be used in a variety of ways to help create a more sustainable future.
As a fast-growing grass crop, sugarcane is certainly a renewable source of energy.
This blog will provide information on the versatility of sugarcane as a crop, potential environmental issues and ultimately answering the question of whether sugarcane is a renewable source of energy.
How is sugarcane a source of energy?
Sugarcane is a species of tall grass, which grows to 2-3m tall. Around 75% of the entire plant is made up of it’s stem.
Like other plants, sugarcane creates its own energy via photosynthesis. This is the process by which plants convert light energy into usable chemical energy. Once converted, this energy can be used by the plant to undertake its day to day activities.
This also means that yes, sugarcane can be a great source of energy for us too. Crops grown for this reason as known as energy crops.
In fact, sugarcane is one of the most efficient photosynthesisers in the plant kingdom. Thanks to this, it’s also one of the most efficient crops in the world to grow and use as a fuel source for human activities.
Using sugarcane as an energy source has been boosted in recent years, mainly due to large scale production in Brazil and other tropical regions. It’s in these regions where plant biomass tends to be most productive, which in turn means it’s more advantageous to use plants for energy production.
What is sugarcane used for?
As the name suggests, sugarcane is responsible for almost 85% of total global sugar production.
In Brazil alone, the world’s largest sugarcane producer, it brings almost 50 billion dollars every year, and provides more than 1.1 million jobs in the sector.
Although the sugar industry is the primary use of sugarcane stalks, there are other products, by-products and merits in general as a crop.
Once the sugarcane is harvested, it’s then crushed to extract the juice. This goes on to create two main products:
- Sugar – the type you buy in the shops
- Ethanol – important for bio-fuels
Ethanol production is the second largest product of sugarcane. Ethanol can be used as a bio-fuel, leading to less greenhouse gas emissions and helping countries with sustainability efforts.
Brazil produces the most amount of ethanol – around 50% of sugarcane in Brazil is destined for ethanol production. This rise has been due to the shift towards more eco-friendly fuel sources, with large countries such as the USA and India passing laws which state fuel solutions are to be composed of up to 25% ethanol.
Another way that sugarcane production can harness energy is through the leftover plant biomass after juicing. Harvesting sugar produces a by-product that goes by the name of bagasse.
Sugarcane secondary use: What is bagasse?
Produced in abundance from the juicing of sugarcane, bagasse is a dry fibrous biomass material. It’s a versatile material that can be used for several things.
Because of this, sugar production is one of the only agricultural processes where the energy output is greater than the input. For every 10 tonnes of sugarcane crushed, a sugar factory produces around three tonnes of bagasse!
including as fuel to produce heat or electricity and as a packaging material.
After the milling process, bagasse can be used as a direct fuel source at the mills to power any biomass boilers. It’s also happy to be stored for future use. In Brazil, bio-energy is accountable for more than 20% of the national Brazilian power energy supply.
The bagasse can also be reformed into paper, bioplastics and manufactured into animal feeds if not used in energy supply.
The leftover leaves and stalks from all the processes described above can be used to produce bio-plastics for packaging purposes. Have a read here of bioplastic uses.
Use of sugarcane summary:
Juice: the sweet liquid inside the sugarcane stalk, which produces sugar and ethanol
Bagasse: the dry and fibrous by-product of the sugar industry, which can be converted into many items, including bio-electricity, paper and in some cases bioplastics.
Straw: the tops and leaves of sugarcane stalks can produce bioplastic products.
Is sugarcane a renewable form of energy?
A renewable resource is one that can be used over and over. It’s one that doesn’t run out as it is naturally replaced. Classic examples include solar, wind, hydro, geothermal, and biomass energy.
Due to this definition, yes sugarcane is a renewable source of energy.
Sugarcane grows quickly, can be harvested quickly, and then replaced in-situ quickly. It’s possibly one of the most renewable plant-based resources we have! These are very similar characteristics to bamboo, which is also a grass. Read more on whether bamboo is really sustainable here.
Not only this, but sugarcane as a biofuel can reduce greenhouse gas emissions by approximately 80% compared to fossil-fuel based energy such as petrol, another sustainability plus!
Are sugarcane plantations bad for the environment?
There have been several concerns regarding the environmental impact of sugarcane.
Let’s have a look at a few of the sustainability issues below, which have also been highlighed by sugarcane.org.
- Land use
Large scale sugar cane production, such as that previously described in Brazil, was once linked to deforestation as demand for sugarcane production increased. However, with accurate and precise land management strategies, land change can occur from pasture land, and not contribute to increased deforestation.
Using sugarcane on land can also increase the soil’s carbon sequestration potential, and can also aid in lowering the soil temperature by almost 1 degree. These are all environmental benefits of sugarcane, if land is managed effectively.
- Water use
Certain sugarcane plantations, such as the Brazilian plantations, require irrigation systems, which leads to increased water use, increased water scarcity and increased soil erosion.
In countries such as Australia, sugarcane is largely unirrigated due to rain-fed systems, and therefore these plantations do not impact water supply.
As with almost all agricultural businesses, the use of pesticides to increase crop yield and to remove the negative effects of pests is evident with sugarcane production.
Programs such as the Smartcane Best Management Practice (BMP) work with farmers to ensure that the use of pesticides and the risk of contamination of water and soils is reduced.
As well as this, organic farming methods can be used to reduce the impact on the environment. This includes promoting the agro-ecosystem related to biodiversity, nutrient cycles and soil health by using organic manures and pest management through the use of non synthetic pesticides.
- Field Burning
Sugarcane production traditionally utilised field burning whereby the straw of the plant was burnt in-situ when the process was not mechanised and the straw wasn’t harvested. However, in recent years the mechanisation of the practice has caused less of a requirement for burning the straw.
For example, Brazil has committed to achieving full mechanisation of production by 2031. In Australia, harvesting has been fully mechanised for 40 years.
Wrap up on sugarcane as a renewable source of energy
Despite the potential environmental concerns, the benefits of sugarcane as a good renewable source of energy surely outweigh these.
The major aspect of sugarcane production which can’t be overlooked is the crop’s role in producing the biofuel with the lowest carbon footprint in the world: ethanol.
Additionally, use of the bagasse by-product in alternative biofuels and as a secondary resource for bioplastics and packaging make the sugarcane industry effectively zero waste.
Because of this, its high energy efficiency and its low carbon footprint make sugarcane one of the most important solutions to sustainability and decarbonisation of the energy industry.
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