As a rule of thumb, waste feedstocks are among the most sustainable inputs for making biobased materials.
One kind with immense potential as an industrial input is banana industry waste. Fibres from biomass left after harvesting have the potential to become a textile alternative to resource-intensive cotton.
The waste crop is also a viable way for some developing nations to build higher value circular bioeconomies around their agricultural sectors and gain more parity with bio-based industries in wealthier nations.
Environmental value of using banana waste
Every year, the world produces about 10 million metric tonnes of bananas a year. 35% of the banana’s weight are in the peels, which result in 3.5 million tonnes of waste per year.
Peels thrown away by consumers are just one part of the issue: banana plantations also leave an immense amount of unused material. After harvesting, almost 60% of banana biomass is discarded. Most of this consists of the fleshy banana tree trunk, which are left to decompose in fields where they grow.
Valorising this plantation waste as biofuels is one possibility, converting chemical energy stored in the trunk and other biomass into heat and electricity. However, banana waste is not an efficient fuel source as most of the heat goes on burning up the considerable moisture content in the trunk and fruit.
A more efficient and sustainable use for banana waste is to transform them into sustainable textiles. The global fashion industry today is hugely reliant on fossil materials, stretching from polyester to water-intensive cotton farmed on overworked soils. As the search for circular textiles at scale intensifies, banana waste could be one of the raw materials ideally placed to supply the demand.
Ugandan community startup fashions banana wearables
As the second biggest banana producer in the world, Uganda is the natural home of banana waste valorisation.
TexFas leads the way in the Ugandan banana waste value chain, having developed technologies for banana fibre extraction and the production of high quality banana fibre textiles and handicrafts including yarn, fabric, and home furnishings like rugs and lampshades. All their crafts are designed to be completely biodegradable.
Founded by Kimani Muturi in 2013, the community-based business takes banana harvest waste from smallholder farmers as well as bulk feedstock material from a company called Tupande Holdings. The feedstock are the banana tree trunks that would otherwise be left to rot in the fields after farmers have taken their harvests.
TexFad is a startup with a difference, geared towards not just sustainability targets but economic development ones too. Its social mission is in providing extra income to farmers as well as vocational qualification and skills training for their weavers and processors. Ultimately, the business’ mission is geared toward generating wealth, local employment, and new industry in a largely agricultural economy where banana farmers struggle with low global prices.
As well as banana products, the startup offers business incubation services including for students while they are still at school. The incubator supports them to develop businesses and products to prototype and then branded products ready for commercialisation.
This community startup model has managed to meld sustainability and social goals – something still relatively rare in the bioeconomy but is essential for a just transition away from fossil fuel products.
Indian banana leather
India is the world’s top banana producer, meaning mountains of waste biomass ripe for picking.
Atma Leather is an Indian startup squarely focused on meeting new demand for sustainable alternatives to animal leather using domestic banana waste. Branded under the evocative name of ‘Banofi’, made from 50% banana stem waste and 30% natural additives, the company claims it has found a truly sustainable alternative to animal skins.
Leather is an industry well known for its chemical pollutants and high water usage. Synthetic leather is no better as it draws petroleum feedstocks. As a staple in the fashion world, brands and luxury houses have been on the hunt for convincing, durable alternatives that use plant-based materials.
Currently, some fossil chemicals are needed to construct vegan leather. Fully plant based materials lack the durability and strength that consumers demand from the products. Here too Banofi makes emissions savings by using 20% recycled polymer as backing material rather than virgin plastics.
Local circularity for global markets
Plant based leathers target the mid to high end luxury market but banana wastes also yield natural fibrous materials that can be worked into more casual styles, particularly for the summer wardrobe and as a more sustainable alternative to cotton.
India’s agri startup Greenikk set up in the banana waste value chain, turning the waste into textiles. Smaller scale enterprises that transform bana waste into handcrafted material do exist in India but what marks out Greenikk is a systematic, scaled way of processing and manufacturing from high volumes of feedstock.
The first component in this scaled system is a mechanised banana waste processing method it has worked out in conjunction with the R&D facility at Theni in Tamil Nadu, a major banana producing region. Reducing costs of processing waste into usable fibres is essential to a viable production process.
The feedstock is also carefully selected based on testing more than 45 banana varieties. Three varieties with the right colour, tensile strength and cellulose content are now in use by the company.
Greenikk taps into a network of more than 600 artisans, transporting consistent supplies of farmed banana waste to be worked into clothes as well as poultry feed. The company has a design team which helps develop products for global markets including in Europe and the USA.
In Bangladesh, traditional knowledge meets new materials
In Bangladesh, another major banana producer, indigenous communities have been hand-weaving saris made entirely from banana fibre under a project supported by the national government. The material replaces the environmentally intensive cotton that normally makes up the traditional clothing.
The initiative, based in the Moulvibazar district, lies right at the other end of the commercial scaling spectrum to Greenik and cannot achieve lower costs without the use of more advanced technologies.
However, it does show that banana waste can contribute to sustainable socioeconomic resilience by affording communities a means of tapping markets by drawing on traditional weaving skills and a readily available resource.
Why the bioeconomy needs waste
Goods made from biological resources are not automatically sustainable. Every raw material has some ecological cost and even renewable ones are no exception. Crops grown for the bioeconomy can heavily contribute towards carbon emissions as well as biodiversity loss and water pollution.
Today, bioeconomy actors are increasingly concerned about the sustainability of the feedstock that goes into their products. In the EU, there has been growing recognition that increased biomass demand is taking a toll on natural ecosystems, highlighting how even biobased industries need conscious management to limit its impacts, especially as economies explore renewable alternatives to fossil fuels.
The objective for the bioeconomy as it sets itself on a sustainable footing is to find high volume, industrially versatile feedstocks that have minimals impacts across as many environmental metrics as possible.
Biowaste fits the bill. This form of feedstock tends to be highly sustainable for several reasons. First, there’s a lot of it – the world is far from a circular economy and waste materials are being produced all the time at scale. Companies and farmers are often only too happy to get paid for this material to be taken away.
Using highly abundant organic waste removes the need for biobased companies to grow virgin biomass from scratch on intensive farms. This means biobased products based on waste minimises negative impacts on biodiversity and water pollution – both consequences of intensive agriculture.
It also cuts carbon emissions by negating the need for fertiliser or the destruction of carbon-absorbing ecosystems to make way for industrial cultivation. Valorising waste can also clean up the environment by removing rotting biomass that would otherwise decompose and release carbon emissions.
Sustainable feedstocks also vary by region. Staple raw materials differ in one region to another depending on the composition of a given country’s agriculture or industries. Leveraging abundant and local raw materials makes for greater economic self-sufficiency and security, reducing the risks of being exposed to potential disruptions to global supply chains.
Utilising local and abundant waste streams could be the basis of a more equitable bioeconomy. Banana valorisation is a good example of this.
With production concentrated in low and middle income countries, new banana value chains based on agricultural biowaste could afford greater financial security for farmers and processors.
Producing food for the global market is an uncertain livelihood at the best of times, with prices prone to lowering or volatility. Supplementary activities like selling biowaste to processors could allow farmers to tap higher value chemical and materials markets for alternative revenue.
Startups like TexFad and projects like the sari-weaving project in Bangladesh are realising this potential by building a sustainable domestic value chain that generates domestic wealth within the country using its own natural resources.
Their initiative challenges current patterns in the bioeconomy where Western companies often extract cheap raw materials from developing nations, only to process and manufacture them abroad. The unequal playing field among developed and developing biobased actors ultimately limits the benefits of the bioeconomy, weakening efforts towards decarbonisation and sustainable economies on a global scale.