Researchers in Ghana are testing a system that will turn cocoa into biofuel — but don’t worry — it uses the green waste produced during harvest, so you can still eat all of the chocolate! The project is funded by the University of Nottingham in the United Kingdom and will be tested in Ghana, one of the world’s largest producers of cocoa.
Chocolate is a multi-billion-dollar international industry, with the bulk of cocoa coming from Africa. “Every ton of cocoa beans harvested generates 10 tons of cocoa pod husks,” says Jo Darkwa, professor of energy storage technologies at Nottingham and one of the project team leads. Husks are typically discarded during harvest after the beans are extracted. Usually, the husks are left to decompose on the cocoa plantation while the beans head to fermentation and drying facilities before they are turned into chocolate. Now, researchers have developed a system that will use the husks as feedstock to generate biofuel. The husks are processed into pellets, or bricks, that can burn in generators and produce “green” electricity.
“Feasibility studies indicate that cocoa pod husks could be converted into valuable biofuels and become an important energy supply for rural areas that only have 15 percent coverage at present,” explained Professor Darkwa.
The many benefits of cocoa fuel
This initiative is not only an innovate green technology, it also has other secondary benefits:
Increase access to electricity
If successful, the project could contribute to the Ghanaian government’s pledge to ensure 100 percent of Ghanaians have access to electricity by 2030.
Reduce deforestation and improve climate and human health
Currently, 80 percent of households in Ghana use wood as their main source of fuel for cooking and heating water. This practice not only leads to widespread deforestation in order to harvest wood, but indoor air pollution from wooden stoves is one of the top four leading risk factors for death worldwide.
If successful, the biofuel system would need workers to collect, transport, treat and process cocoa pod husks, which would create additional jobs and provide income for rural communities.
Cocoa as chocolate, cocoa as compost
Since it is the beans that are used to make chocolate, the husks are simply bio-waste, and therefore the biofuel system would not take away from farmers’ profits in any way— in fact it would augment the profitability of the entire cocoa pod.
However, cocoa pod waste is an important source of nutrients for cocoa trees. During harvest, ripe cocoa pods are collected and piled throughout the plantation. When the farmers are ready to extract the beans, the pods are cracked open and usually left in a heap to decompose. When husks biodegrade, they are an incredibly rich source of nutrients that help trees grow, improve soil quality and reduce plant disease. Studies show that the decaying pods host beneficial fungi and microbiotics, so will farmers and their crops be losing out on natural fertilizer if they ship their husks off to biofuel systems?
Farmers with the capacity to do so might collect and bring the husks to an on-site composting location, but most small farmers do not have the capacity to process or evenly distribute the nutrients from the pile of decomposing husks and rely on nature to take its course. Farmers who do maximize the use of the compost may prefer to continue to do so, however those without that ability now have the option to profit from electricity generation instead.
Testing the system in Ghana and the world
“Undoubtedly, provision of sustainable energy services through cocoa pod husks would go a long way towards improving the quality of lives and thus alleviate poverty in rural communities as well as fight against climate change,” Professor Darkwa told Climate News Network.
The project team is expected to test a prototype of their system at the Kwame Nkrumah University of Science and Technology in July 2019. The plan is to design, build and operate a small-scale bio-power electricity generation unit that burns husks in a gasification system. Each system includes a gasifier, small generator, solar drier and pelletizer and costs approximately US $50,000. If the prototype is successful, the system could be replicated in other countries following additional feasibility studies.