Fuel cell system

Heat exchanger is arranged downstream of a gas purification unit and heats purified hydrogen-rich gas, the gas purification unit having a separate cooling unit, or a heat exchanger is arranged downstream of the cooling chamber in the coolant stream of the fuel cell and heats the coolant. Fuel cell system comprises a heat exchanger for preheating a crude fuel/water mixture; a vaporizer unit for producing a gaseous educt gas stream from the mixture; a gas producing unit for producing a hydrogen-rich stream from the educt gas stream; a cooled gas purification unit for selectively removing carbon monoxide from the hydrogen-rich gas; and a fuel cell for converting the hydrogen-rich purified gas. The fuel cell has an anode chamber, a cathode chamber, and a cooling chamber through which coolant flows. A heat exchanger is arranged downstream of a gas purification unit and heats purified hydrogen-rich gas, the gas purification unit having a separate cooling unit, or a heat exchanger is arranged downstream of the cooling chamber in the coolant stream of the fuel cell and heats the coolant. Preferred Features: The system further includes a catalytic unit for preparing thermal energy.