SABI Magazine Volume 9 Issue 4 | Page 34

Biofuels How to unlock the potential of papyrus wetlands in Africa By Michael Jones and Matthew Saunders M ost households in tropical sub-Saharan Africa - over80% - use some form of biomass, such as charcoal or wood as their primary source of energy, mainly for cooking. They source this biofuel from scrublands, savannahs and forests. Wood is the main source of domestic energy for rural populations while charcoal is the major source in urban areas. But the capacity of biomass to provide the energy requirements of sub-Saharan tropical Africa is declining. This is problematic because the numbers that depend on it are growing as populations increase. By 2040 there will be an estimated 40% increase in the demand for biofuels. This will increase the pressure on forest biomass stocks in particular. It has long been recognised that this supply of wood is not sustainable and its continued use is leading to the destruction of natural woodlands and scrublands and a catastrophic loss of biodiversity. It has been predicted that the current rate 32 SABI | APRIL / MAY 2017 of fuel wood consumption could exhaust resources within the next decade or two so there’s an urgent need to find alternative sources of biofuel. One of the, as yet, untapped sources of biofuel is the prolific vegetation that grows in wetlands which cover approximately 6% of sub-Saharan Africa. Many of the wetlands are covered by papyrus vegetation that’s been shown to have record-breaking growth rates. Harvesting this papyrus as a renewable source of energy has the potential to alleviate pressures on native forest ecosystems which currently act as the main source of fuel sub-Saharan Africa. Some plants are better for biofuel use than others The ideal plant used for fuel grows fast, can be harvested easily and then will regrow quickly. Fast growth depends on using the light available for photosynthesis as efficiently as possible and some plants are 30-40% more efficient than others. .. We now know that one of these ‘super-efficient’ plants is papyrus which was extensively cultivated in Africa throughout history, most famously to make paper in ancient Egypt. Today, papyrus has largely disappeared from Egypt but it remains the dominant plant in wetlands in the Nile basin. These wetlands stretch from the source of the White Nile in Lake Victoria and passes through Uganda, South Sudan, and Sudan into Egypt. Papyrus grows quickly and its high biomass can be put to a number of uses. It is usually harvested by hand and stacked for partial air drying before it is used. It’s then used to make furniture, mats and baskets. But currently no market for its use as biofuel has been developed. There are a number of reasons for this, the most significant being that papyrus needs to be converted into a suitable combustible form before it can be used as a biofuel. Papyrus stems aren’t dense enough to burn directly in stoves so they need to be densified or converted into charcoal. Trials to compress the papyrus into briquettes have been carried out in Rwanda. The briquettes were manufactured in a single piston press as a long cylinder with a diameter of 6 cm. A pilot factory was established near