Millions of tonnes of spent cocoa pods go to waste every year. They could be used to generate power, as a project about to be field-tested in Ghana suggests
Access to reliable, affordable sources of energy is an issue in many countries. In rural areas of Ghana in which there is little or no grid infrastructure, electricity is a rarity. It is unrealistic to expect the electricity grid to be expanded into these areas, but the country has a resource that it could use to generate electricity on a scale suited to the needs of individual communities. That resource is spent cocoa pods or husks, most of which are unused and left to decay.
That is the thinking behind the Implementation of Bio-Rural Energy Scheme (IBRES) project, which is backed by the UK government’s Global Challenges Research Fund project and led by University of Nottingham.
Conducted working closely with the Ghana Cocoa Board (Cocobod), the aim of the project is to determine whether electricity generated by syngas (synthesis gas) produced from cocoa pods can bring reliable power to parts of Ghana that are far from the grid.
Syngas is a mixture consisting of carbon monoxide, carbon dioxide, and hydrogen and is produced by gasification of a carbon-containing fuel into a gaseous product.
Synthetic gas would drive a generator
The Nottingham University-led project aims to make syngas from the husks of cocoa pods, which usually go to waste after they have been processed and cocoa beans removed. The process being tested in the project uses partial oxidation of the material in spent cocoa pods to produce syngas that drives a generator to produce electricity.
Professor Jo Darkwa, a Professor of Energy Storage Technologies at University of Nottingham told C&CI that bringing power to remote communities would have many benefits. Apart from the obvious ones such as helping to alleviate poverty, wood is often used in rural communities for cooking, which leads to degradation of the landscape. Regular exposure to wood smoke has also been associated with a range of health issues.
In contrast, the use of spent cocoa pods is attractive as source of power for several reasons, not least because the basic raw material is readily available: Ghana’s cocoa sector produces around 8 million tonnes of pod waste every year.
Providing power and generating jobs
“Ghana is the second largest producer of cocoa in the world and every tonne of cocoa beans harvested generates around 10 tonnes of cocoa pod husks,” Professor Darkwa explained. “Only a little of this material is re-used – such as for the production of compost.”
Professor Darkwa told C&CI that his team had been looking for an intermediate-level energy technology that would not need outside support if used in rural areas. Ideally, the technology used in it could be built and maintained locally and doing so would create jobs if people such areas are trained to operate it. Using spent cocoa pods ticks all the boxes.■ C&CI
This is an extract of an article first appeared in the November’19 issue of C&CI. Click on subscribe now if you wish to read more informative articles in the current and future issues of C&CI.