Biomass sounds like a brand new buzzword that we’ve only really added to our vocabularies in the last thirty years or so. However, the reality is that biomass has been around since humans discovered fire – we’ve just become a lot smarter about how we use plants as energy in recent years, in reaction to climate change and the long term implications of using fossil fuels.
Our main sources of plant-based biomass are wood from trees and a variety of crops such as corn, sugarcane, bamboo and even hemp. These sources of biomass are fermented in order to produce ethanol, which has many uses within the cosmetics, medicine and food industries, but it’s also used as a biofuel to reduce carbon emissions by around 30%.
One plant growing in popularity in the UK for its use as a biofuel ingredient is Miscanthus. Also known as Silvergrass, this plant is a high-yield crop which practically grows itself, as it doesn’t need replanting. World leading Miscanthus specialist Terravista aims to replace the global dependence on fossil fuels with this efficient, sustainable and profitable crop, and is already supplying to power stations around the UK.
There are also many unusual plants around the world that are perhaps overlooked because they are too expensive or impractical to grow commercially as biomass. I visited the Energy Plant Garden at the South China Botanical Garden, where a series of plants had been identified for their potential as a biofuel ingredient. Wandering around the garden really gives you perspective on the capabilities of plants and how they can help us create a greener, more energy efficient world!
Here are nine unusual and unexpected plants I spotted in the Energy Plant Garden.
1. Miscanthus floridulus
A perennial giant ornamental grass, used for biomass energy production. The unopened flower spikes are also edible.
2. Mesua ferrea (Ceylon Ironwood)
The wood is very heavy, hard and strong, which means that it can be used for railroad ties and heavy structural timber. Its seeds contain 78.99% oil, which makes it ideal for industrial purposes.
3. Camellia crapnelliana
This plant is grown for its attractive white flowers, rusty brown bark and red-brownish round fruits. Its seeds contain 17% oil, and are often crushed and used as cooking oil. It’s endemic to China and is listed under class-II of national protected plants.
4. Sindora tonkinensis
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This plant provides a stem xylem abundant with flammable liquid which can be directly used in diesel engines after filtration. It’s high quality wood is also sought after for high end furniture, however the plant is currently endangered in the wild. The blooms are also in demand from beekeepers, who want high quality honey!
5. Senna siamea (Siamese Cassia)
The Senna siamea has medicinal values and, after boiling, the leaves, tender pods and seeds are edible. Its wood is almost black – an ideal firewood with fast growth. It’s a useful plant for inter-cropping, windbreaks and shelter belts.
6. Leucaena leucocephala
Once nicknamed the Miracle Tree, thanks to its myriad of uses, however the rapid growth means it can also be invasive, 20 ft in two to three years! This plant is used in foresting barren hills, as cattle fodder, food for humans, fixing nitrogen into the soil, and for biomass production. It’s rich in hydrocarbon compounds, and its burning capacity can reach up to 2/3 as petrol, which is why it’s known as ‘burning wood’, with a residual use for firewood and charcoal production.
7. Jatropha curcas (Physic Nut)
Jatropha curcas seeds contain more than 60% oil, which can be processed into gasoline and diesel. It’s superior to the popular China 0# Light Diesel Fuel in many aspects, and is known as the ‘diesel tree’.
8. Vernicia fordii
The drying oils extracted from the seed kernels of this plant have a wide variety of industrial applications. The fruit skin can produce activated carbon, or extract potassium carbonate, which is a catalyst for biodiesel production.
9. Vernicia montana (Tung Tree)
The kernel content of this plant consists of up to 60-70% oil, which can be used in the manufacture of paint, electrical applicances and synthetic rubber. Tung oil, also called China wood oil or nut oil, has traditionally been used in lamps in China. In modern times, it is used as an ingredient in paints and varnish.
Which plant were you most surprised about? Let me know in the comments below!
Michael has been involved with gardening and plants since he was just five years old. He is a self-professed Plant Geek, and was listed in the Sunday Times top 20 most influential people in the gardening world, thanks to his plant hunter role at Thompson & Morgan.
Michael was responsible for new plant introductions such as the Egg and Chips plant and the FuchsiaBerry and keeps busy travelling the world in search of new plants as well as lecturing worldwide, including stints in Japan. He is very active on social media – so why not give him a follow at @mr_plantgeek or Facebook – and writes a plant-focused Substack called Grow This, Not That.