In recent years, Italy has become the third largest agricultural biogas producer in the world after China and Germany.
The utilization of biogas in the country is still restricted to power generation with limited use of cogenerated heat, whereas other utilization pathways focusing on biogas upgrading to biomethane remain unexplored.Given the high development of natural gas pipelines and the presence of numerous compressed natural gas (CNG) refuelling sta- tions in Northern Italy, significant market opportunities for biogas may also arise in the transport sector.
The use of biomethane as a vehicle fuel offers several advantages compared with other biofuels, such as first-generation bioethanol and biodiesel, the most prominent of which being a more favourable energy balance and the possibility of adopting a wide variety of organic materials for its production. However, the requirement to upgrade the biogas to biomethane of adequate quality for transport fuel use, the compression of the gas for storage and transport, and the lack of refuelling infrastructure, represent significant barriers to the deployment of biogas-based vehicle fuels in many European countries.
In this thesis, prospects for agricultural biogas in Northern Italy have been explored. The focus is on its utilization as compressed biomethane for vehicles (CBM), as com- pared to other utilization pathways (i.e. power only option, simultaneous production of electricity and heat and injection of biomethane into the national gas grid).
The methodology considers the use of different spatially explicit optimization models to forecast future biogas supply chain structures that minimize overall costs and en- vironmental impact. Previous and actual biogas promotion schemes and other policy instruments to foster the production of biomethane as a vehicle fuel have been included in the assessment and applied to regional as well as macro regional case studies.
The results show that upgrading biogas for transport applications carries some envi- ronmental advantages, especially compared with its utilization solely for the production of electricity. However, promoting the development of a biomethane market solely with the introduction of environmental taxes is the least effective option as the environmental benefit in terms of emissions mitigation is very little. On the other hand, the intro- duction of current biogas incentive mechanisms would favour the development of CMB technologies in areas with promising biomethane market potentials.
