Energy, environmental and agronomic valorizations of the rural biomethanisation of the bovine biomass

This work consists in studying various possible valorizations of the rural biomethanisation applied to the bovine dejections. The follow-up of the adopted digester related to: the estimate of the qualitative productivity (% CH4, % CO2, % H2S and % H2; LCV and HCV) before and after conditioning. For the analysis of the gas composition and the estimation of the calorific values, we had recourse to the technique of chromatography in gaseous phase (CGP); analysis of certain environmental parameters (SM and BDO5), in order to establish the corresponding assessments of depollution; possibilities of agronomic valorization except ground of the residues of the biométhanisation (the methacompost as full or partial substitute for peat and / or compost and juice process plants gardeners as fertilizer).The significant preliminary results rising from this work are the following: the conditioning of rural biogas product made it possible to improve the energy performances; the process of rural biomethanisation allowed an insufficient reduction of the polluting load as for SM as for BDO5; the use of the methacompost as a partial substrate of culture gives encouraging results for the growth in height of the pepper seedlings; the juice of process diluted at a rate of 75% showed an interesting power fertilizing.Ultimately, the current trend towards the agrobiologic practices encourages the agronomic use of these digestats, because of the importante depollution generated.