The challenges of bagasse valorisation in French overseas departments and regions (ODRs)
The decisive role of sugar cane cultivation in the economy of the ODRs that produces it, as well as the French desire to make these territories energy self-sufficient in 2030 (Energy Transition Law for Green Growth, 2015), are all factors that are pushing these territories to develop innovation around sugarcane bagasse.
The valorisation of sugarcane bagasse represents various challenges for these ODR. First of all, the use of bagasse does not compete with food production from sugar cane (sugar, industrial rum, agricultural rum), which is one of the pillars of the regional economies of Martinique, Guadeloupe and Reunion. In addition, it is a local resource, which avoids the importation of other materials or fuels. Finally, farmers receive a “sugarcane bagasse bonus” per tonne of sugarcane bagasse delivered, which constitutes an additional income for them.
Even if it is full of water, sugarcane bagasse has an interesting calorific value (1.9 KWh/kg, or 19 MWh/tonne) for these island regions. Therefore the energy valorisation of this resource allows both to supply sugar factories with electricity and heat and to resell the excess of electricity produced, in order to supply the territorial electricity grid.
Thus, in Reunion Island, approximately 530,000 tonnes of sugarcane bagasse are recovered each year, preventing the import of nearly 140,000 tonnes of coal. Indeed, this sugar cane residue represents the first type of biomass used in Reunion Island (where sugarcane bagasse represents about 10% of the electricity produced on the island each year), Martinique and Guadeloupe. The company Albioma (formerly known as Séchilienne-Sidec) specialized in the energy valorisation of this cane waste, operating five bagasse/biomass power plants in all these areas (Galion 2 in Martinique, Le Moule and the new Marie-Galante power plant in Guadeloupe, as well as Bois Rouge and Le Gol in Reunion).
On the other hand, sugarcane bagasse can be recovered as a material. Indeed, vegetable bio- plastics (biodegradable packaging and containers) are made from this agricultural waste. Sustainable paper pulp can also be made with sugarcane bagasse, an alternative to paper made from wood fibres, which irreparably destroys the biodiversity of forest ecosystems every year.
However, sugarcane bagasse has several weaknesses that are obstacles to make its valorisation a priority. Even if the exploitation of bagasse does not affect the sugarcane sector (sugar and rum production), the opposite is not true. Indeed, sugarcane bagasse depends on the sugarcane sector, which depends heavily aswell on European and French funds to support agricultural sectors. The valorisation of this agricultural residue, therefore, does not really ensure the independence of these territories. In addition, sugarcane bagasse is only available during the sugar season (five months of the year), making it an intermittent resource.