NOVELTY - A fuel cell system (100) comprises a gaseous fuel tank (110) containing a gaseous fuel; a liquid fuel tank (120) containing a mixture of a sulfur-free liquid fuel and water; a reformer (140) for generating a hydrogen-rich gas from the mixture of liquid fuel and water received from the liquid fuel tank via a liquid fuel supply line; and a reformer burner (130); where the liquid fuel tank is connected to the gaseous fuel tank, and the mixture of liquid fuel and water is supplied to the reformer by the pressure of the gaseous fuel tank.    USE - For generating electrical energy or electricity.    ADVANTAGE - The fuel cell system facilitates the supply of liquid fuel to the reformer using the pressure from the gaseous fuel tank, and hence does not require an additional liquid pump for supplying liquid fuel to the reformer. The fuel cell system produces reformed/hydrogen-rich gas with low concentrations of carbon-monoxide, at lower temperatures than prior-art fuel cell systems. Hence, the reformed gas is directly supplied to the fuel cell stack without further manipulation and without use of conventional shift reactor. The fuel cell system automatically controls the amount of the liquid fuel supplied to the reformer from the liquid fuel tank, according to the consumption of the hydrogen-rich gas by the fuel cell stack, using the pressure regulator. The fuel cell system does not include a desulfurizer, as the liquid fuel does not contain sulfur.    DETAILED DESCRIPTION - A fuel cell system (100) comprises a gaseous fuel tank (110) containing a gaseous fuel; a liquid fuel tank (120) containing a mixture of a sulfur-free liquid fuel and water; a reformer (140) for generating a hydrogen-rich gas from the mixture of liquid fuel and water received from the liquid fuel tank via a liquid fuel supply line; and a reformer burner (130) to heat the reformer by burning the gaseous fuel received from gaseous fuel tank; where the liquid fuel tank is connected to the gaseous fuel tank, and the mixture of liquid fuel and water is supplied to the reformer by the pressure of the gaseous fuel tank. The fuel cell system includes a fuel cell stack (150) for generating electrical energy from the hydrogen-rich gas received from the reformer. The fuel cell system further comprises a recovery line (152) between the fuel cell stack and the reformer burner, to recover an unreacted gas from the fuel cell stack to the reformer burner; a pressure regulator (160) on the recovery line; and a controller (155) to manipulate an amount of the gaseous fuel supplied to the reformer burner and an amount of unreacted gas supplied to the reformer burner via the recovery line, for maintaining a reformer temperature of 220-250degreesC to minimize the concentration of carbon monoxide in the hydrogen-rich gas produced by the reformer. An INDEPENDENT CLAIM is included for a method of generating electrical energy involving flowing gaseous fuel along a gaseous fuel line from the gaseous fuel tank to the reformer burner, to heat the reformer for reformation and enrichment of hydrogen; flowing the mixture of liquid fuel and water from the liquid fuel tank to the reformer along the liquid fuel line, by pressurizing the liquid fuel tank from the pressure contained in the gaseous fuel tank, so that the reformer produces a hydrogen-rich gas; and flowing the hydrogen-rich gas from the reformer to the fuel cell stack for producing electrical energy.    DESCRIPTION OF DRAWING(S) - The figure shows a configuration of a fuel cell system.    fuel cell system (100)    gaseous fuel tank (110)    burner valve (112, 122)    liquid fuel tank (120)    reformer burner (130)    reformer (140)    fuel cell stack (150)    recovery line (152)    controller (155)    pressure regulator (160)    heat exchangers. (171, 172)