Low cost biogas purification systems: LCA study = Low cost biogas purification systems: LCA study

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. The data of the case study was collected from the Edmund Mach Foundation of Trento's "Up-ASH" plant, where biogas is produced through the anaerobic digestion process for the organic fraction of municipal solid waste (OFMSW) and using low-cost technology to adsorb impurities from biogas using wood-chip ashes coming from a district heating plant. This technology is meant to enhance the characteristics of biogas increasing the methane ratio and lowering carbon dioxide. This method identifies ash as a key player turning waste into a primary component of the biomethane production cycle. Moreover, this strategy has the potential of upgrading technical advancement in the field of a circular economy focusing on the re-use of all-natural resources. To analyze the life cycle impact of the purifying system, ISO 14040 and ISO 14044 frameworks were followed. By applying these frameworks criteria the life cycle assessment of the purifying was studied defining the goal and scope of the LCA study and setting the boundaries, inventory analysis of the system, calculating the impact, and interpreting the result. GaBi software with an educational database was used as a tool for analyzing the LCA of the system by tracking and defining all flows and processes in the system. The functional unit chosen is 1 m3 of biogas input and the impact assessment method used is CML 2001 for the analysis. The analysis result shows that the avoided effects associated with CO2 capture and biomethane production benefit a significant number of the indicators studied, but the final disposal of ash into landfills leads to negative contributions on the indicators, so the plausible solution might be to dispose of the ashes in some other way which research and then politics should intervene to dispose of these materials sustainably.