Environmental impact assessment as a complement of life cycle assessment. Case study: Upgrading of biogas

•This work presents a comparison between the LCA and EIA in the upgrading of biogas.•Three upgraded biogases formed using the absorption–desorption process are compared.•The advantages and disadvantages of each tool are analyzed.•The EIA and LCA are not opposites but rather are complementary tools. This work presents a comparison between an environmental impact assessment (EIA) and a life cycle assessment (LCA) using a case study: upgrading of biogas. The upgrading of biogas is studied using three solvents: water, physical solvent and amine. The EIA follows the requirements of the legislation of Santa Fe Province (Argentina), and the LCA follows ISO 14040. The LCA results showed that water produces a minor impact in most of the considered categories whereas the high impact in the process with amines is the result of its high energy consumptions. The positive results obtained in the EIA (mainly associated with the cultural and socioeconomic components) make the project feasible and all the negative impacts can be mitigated by preventive and remedial measures. From the strengths and weaknesses of each tool, it is inferred that the EIA is a procedure that can complement the LCA.