A significant amount of carbon products are emitted as a result of burning fossil fuels, the direct release of such products has a bad effect on the environment and has a clear contribution to raising global warming temperature. This calls for the immediate adoption of renewable energy sources to mitigate the impact of fossil fuel combustion emissions. This study aims to apply the environmental analysis, through the life cycle assessment (LCA) methodology for a purification operation of the biogas to identify the main contributions to the impacts due to the various sub-processes in the analyzed low-cost system that use ashes as a medium to eliminate unwanted contained in the biogas.