Sustainability of Biogas Based Projects: Technical and Economic Analysis

Biomethane is a renewable gas produced by the transformation of organic matter. It can lead to emissions reduction and it contributes to increasing methane production. Incentive policies favour its development and for this reason, the objective of this paper is to investigate the economic performance of biomethane plants and their process monitoring by electronic systems. Mathematical modeling is here presented to study the financial feasibility of biomethane plants in function of the size (100 m3/h, 250 m3/h, 500 m3/h, 1000 m3/h), the feedstock used (organic fraction of municipal solid waste and a mixture of 30% maize and 70% manure residues on a weight basic) and the destination for final use (fed into the grid, destined for cogeneration or sold as vehicle fuel). From an economic point of view the plant performance is studied by economic tools as Net Present Value and Discounted Payback Time and the uncertainty analysis is implemented using Monte Carlo method. Moreover, from a technical point of view, process monitoring is analyzed to understand what happens in a biomethane plant and help to maintain a stable process. The results show that the profitability of biomethane plants is verified in several scenarios presenting losses only if subsidies were removed.