Liquefied Natural Gas supply chain: optimization of operational, environmental and social costs

In this paper the problem of distributing Liquefied Natural Gas (LNG) from a set of gas storage facilities to a set of gas stations is addressed. Each gas station indicates a time window where the deliver has to fall in. A time-dependent network is considered, where the traffic conditions change in relation to the road type and the daily time slice. The objective function considers operational, environmental and social costs. The first category of costs refer to the driver, overtime, vehicle use, fuel; the environmental costs are proportional to the CO
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emitted by the vehicles, that depends on the vehicle speed due to the traffic conditions; the social costs depend on the gas station manager satisfaction (in terms of early and delay delivers costs) and on the effect of the noise in the daily time slices. Different heuristics have been tested to optimize of transportation and the storage of a LNG in Italy, based on a real urban and extra urban network and traffic historical data.