NOVELTY - Desulfurization appliance (200) comprises: a hydrocarbon desulfurization bed (204) with bed characterization limit, having a fuel inlet (224), a refined fuel outlet, and an air/sulfur outlet; a heat stream (208) in thermal communication with the hydrocarbon desulfurization bed; and a purge valve in fluid communication with the hydrocarbon desulfurization bed and the air/sulfur outlet. The purge valve is configured to open when the bed characterization is exceeded.    USE - The desulfurization appliance is useful for producing desulfurized fuel, which is configured to provide desulfurized fuel as an input to a fuel cell system (claimed).    ADVANTAGE - The desulfurization appliance: is capable of self regeneration of hydrocarbon desulfurization bed contained in it (claimed); generates high efficiency power, heating and/or cooling on demand, while improving cooling, heating and power (CCHP) operation, reducing maintenance costs and preserving the investment in the fuel cell system; produces high utilization of a fuel cell or group of fuel cells (fuel cell stack) using both the electric and thermal energy generated by the fuel cell for use within a structure throughout the year, thus provides near complete energy recovery during varying electric and thermal load conditions; allows for the use of readily available hydrocarbon fuels comprising natural gas; can be operated at near atmospheric pressure, thus reduces parasitic losses from compressors and blowers; utilizes close-coupled heating and cooling systems, which share plumbing and heat transfer media thus creating simple, integrated appliance; includes optimized power electronics, which drop-in replacement for existing heating, cooling and hot water systems, thus reduces expense of using CCHP system as replacement; utilizes grid integration to supplement the CCHP system during peak load, most expensive component in the system, the fuel system can be right-sized for maximum utilization, rather than sizing the fuel cell system for peak load power usage (ensuring an over capacity component that is challenged to return its capital cost) or under sizing the fuel cell system such that it runs beneath the power usage profile of the application; provides efficient CCHP system without sulfur compound (sulfur oxides) emissions; and does not require liquid water management and power density is traded off for system efficiency.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for operating a fuel cell system, comprising providing the desulfurization appliance having a hydrocarbon desulfurization bed determining a sulfur content in a refined fuel exiting the hydrocarbon desulfurization bed, comparing the sulfur content to a predetermined sulfur limit and self regenerating the hydrocarbon desulfurization bed when the sulfur content exceeds the predetermined sulfur limit.    DESCRIPTION OF DRAWING(S) - The figure shows block diagram of fuel air water delivery module including desulfurization appliance.    Desulfurization appliance (200)    Hydrocarbon desulfurization bed (204)    Heat source stream (208)    Air source stream (212)    Hydrocarbon inlet (224)