Economic and environmental savings from upgraded biogas applications

The directive 2009/28 CE state a mandatory 10% minimum target to be achieved by all member states for the share of biofuels in transport petrol and diesel consumption by 2020. In the Directive, the advantage, in terms of greenhouse gas (GHG) saving, of agricultural manure and municipal organic waste treatments for biogas production is highlighted. Key biogas applications are identified in both direct energy conversion (combined heat and power-CHP) and in its use as biomethane (biogas upgrading). In the attempt to achieve EU targets, Italian incentive policies are moving from generation-based incentive (GBI) towards premium for reducing GHG emissions from power plant. In this context, the evaluation of biogas applications feasibility, from both an economic and an environmental point of view, is required. In this paper economic and environmental savings obtainable from both direct biogas application (CHP) and upgraded biogas applications (in-grid feeding or traditional petroleum based fuel replacement) are compared. Municipal organic wastes as substrate for biogas production have been considered. Economic and environmental performances of different scenarios are evaluated. Scenarios differ for biogas treatments and final applications. In all scenarios, emission savings have been calculated by means of an LCA approach. In case of CHP application, GHG emissions are compared with those corresponding to the national fuel mix used to generate electricity. In case of in-grid feeding of upgraded biogas (biomethane), GHG from biomethane production are compared with emissions from extraction, production and transportation of natural gas. Concerning fuel replacement application, Well To Tank (WTT) and Tank to Wheels (TTW) approaches are implemented in order to evaluate the Well To Wheels (WTW) environmental performance of the scenario considered. The purpose of this research is twofold: on one hand, to compare benefits in terms of GHG and local (NOx, PM, CO) emissions achievable of biogas/biomethane applications; on the other hand, to identify effective incentive policies allowing to give economic feasibility to biogas/biomethane applications.