Boil-off recovery system for natural gas stations: an approach to increase energy efficiency and reduce greenhouse gases

Improving the efficiency of energy use is of utmost importance in the context of climate change. Indeed, greater efficiency in the end-use of energy will make a significant contribution to lowering primary energy consumption and reducing CO2 and other greenhouse gas emissions. This paper presents an approach that enables a compact liquefied natural gas station to operate without being connected to the public electric grid. It is achieved by using the Boil-off gas generated by the vehicle supply process and feeding it to a generator which, together with a photovoltaic (PV) system, can produce electrical energy. Results from a year of trial operations at the station in Escariz, Portugal, demonstrate that it is possible to recover an average of 8.66 kg of Boil-off gas daily while generating a 345% excess of electrical energy when combined with the PV system, enabling the station to be self-sustainable in terms of electricity. Based on the experimental data and calculation methodology, the project was able to earn an estimated monthly revenue of €176.27 throughout the study period while also preventing the emission of 8549 kg of CO2 equivalent from natural gas combustion in vehicles.