1Institute International Engineering Water and Environment (2iE), Laboratory Biomass Energy and Biofuels, Wetenschapsstraat 01BP594, Ouagadougou 01, Burkina Faso
2CIRAD-PERSYST, UPR Biomasse Energie, TA B-42/16, 73 Avenue J.-F. Breton, 34398 Montpellier Cedex 5, France