The environmental impact analysis is focused on emissions, especially those of CO2, NOx, and SO2. The emissions related to ash transport and fertilizer production and transport need to be calculated to obtain the total environmental impact.

8.4.1 Combustion of the Cacao Shells in the Bioenergy Plant

Per hectare cacao plantation in Cote d’Ivoire, 74 kg cacao shells are produced. These shells are combusted in a bioenergy plant. In Table 8.8, an overview is given of the main characteristics of the circulating fluidized bed combustion plant for the combustion of 74 kg cacao shells. The combustion of 74 cacao shells produces

5.3 kg filter ashes. Only the filter ash is suitable as a fertilizer. The bed ash consists of approximately 69% bed material (sand) and additive, whereas the filter ash contains only 13% bed material and additive. It is assumed that all potassium is present as K2CO3.