Assessing environmental benefits of the transition from standard fossil fuels to liquefied natural gas: The Sardinia Region case study

The ever-increasing attention to environmental pollution and the greenhouse effect, together with the need to reduce harmful emissions into the atmosphere, has led to a general enforcement of stricter legislation worldwide which imposes the adoption of more efficient and sustainable solutions in many different fields. The use of traditional fossil fuels must be reduced, favoring both renewable energy sources and alternative fuels. This paper outlines a procedure for calculating the environmental advantages of using liquified natural gas (LNG) instead of traditional fossil fuels in terms of reduced emissions: it is based on the choice and application of emission factors (EFs), available through a dedicated and extensive database managed and updated by the European Environmental Agency (EEA). Whenever the EF database lacks data, additional literature studies and databases are used to integrate the missing information. The proposed methodology is then applied to the Sardinia Region: starting from data regarding regional energy needs, the emissions deriving from the current situation are calculated to define a reference point to be compared with two forecast scenarios. These assume that, over a 10-year horizon, certain shares of fossil fuels will be substituted by LNG. Comparisons are made between the emission levels of six different compounds (PM2.5, PM10, CO, CO2, NOX, SOX) showing that, overall, LNG adoption can be considered effective in reducing air pollution for the compounds considered. In particular, as an example, reductions of up to 70 % of PMs and 38 % of CO2 can be achieved for the thermoelectric sector, whereas for the transportation sector the reductions of the same compounds can be respectively 15 % and 10 %.