System and method for recovery of redundant gaseous fuel from a gaseous fuel supply system

A method for recovery of redundant gaseous fuel from a gaseous fuel supply system of a clean combustion engine having a fuel injector, the gaseous fuel supply system comprising:

• a first gaseous fuel tank arrangement comprising at least a first gaseous fuel tank storing pressurized gaseous fuel between 70 bar and 800 bar, such that at least 70%, based on volume, of the fuel in the first gaseous fuel tank is gaseous;
• a fuel rail arranged to supply gaseous fuel to the fuel injector;
• a first supply line arranged to supply pressurized gaseous fuel from the first gaseous fuel tank arrangement to the fuel rail;
• at least one return line arranged to transport redundant gaseous fuel from at least one of the fuel rail and the clean combustion engine;
• a compressor configured to increase the pressure of the gaseous fuel;
• wherein the at least one return line is arranged to supply the redundant gaseous fuel from the fuel rail and the clean combustion engine to the first gaseous fuel tank in the first gaseous fuel tank arrangement;
• the method comprising:
• in response to a reduced demand in injection pressure of the gaseous fuel to the clean combustion engine, transporting redundant gaseous fuel away from the fuel rail and the clean combustion engine via the return line to the compressor, and pressurizing the redundant gaseous fuel by the compressor to above the pressure in the first gaseous fuel tank and subsequently transporting the pressurized redundant gaseous fuel to the first gaseous fuel tank.