3.3. LBG scenario
In the LBG scenario, the raw bio gas was assumed to be first upgraded by the same technology as in the CBG scenario. Thereafter, the remaining CO2 was removed by a chemical scrubber. The bio methane was chilled to − 161 °C and liquefied by the closed Bray ton cycle method, where N2 is the refrigerant fluid. Liquefaction requires
0.63 kWhel/Nm3 UG [31]. LBG was stored in a vacuum insulated
vessel and delivered by semi-trailer with a tank capacity of
33,000 Nm3. The average fuel consumption (round trip) of a LBG semi-trailer is 0.46 L/km [3]. At the fueling station, the LBG was transferred from the vessel by transfer pumps through vacuum insulated pipes to the dispenser, which dispenses fuel at a pressure of 5–8 bar [3]. The electricity consumption at the fueling station is 0.025 kWh/m3
UG and the methane emissions are 0.00076 g CH4/kWh [31,32].