A pre-reformer comprises a non-electrically conducting gas tight duct and an electrically conducting wire arranged in the duct. The electrically conducting wire is electrically isolated from the duct. The duct has an inlet for receiving a hydrocarbon fuel at a first end and an outlet for supplying a pre-reformed hydrocarbon fuel at a second end. At least the inner surface of the duct is chemically inert with respect to the hydrocarbon fuel. An electrical power supply is electrically connected to the electrically conducting wire and a control means controls the supply of electrical current through the electrically conducting wire to provide thermal decomposition of higher hydrocarbons in the hydrocarbon fuel. The performer reduces coking in associated fuel cells and other parts of a fuel cell system.
1. A method of pre-reforming a hydrocarbon for use in a fuel cell comprising:
supplying only a hydrocarbon fuel to an inlet of a pre-reformer comprising a gas tight duct and at least one electrically conducting member arranged in the duct, the at least one electrically conducting member is electrically isolated from the duct, the duct having the inlet for receiving the hydrocarbon fuel at a first end and an outlet for supplying a pre-reformed hydrocarbon fuel at a second end, at least the inner surface of the duct is chemically inert with respect to the hydrocarbon fuel, an electrical power supply electrically connected to the at least one electrically conducting member and control means to control the supply of electrical current through the at least one electrically conducting member;
heating the hydrocarbon fuel in the duct by supplying electrical current through the at least one electrically conducting member to provide thermal decomposition of higher hydrocarbons in the hydrocarbon fuel in the absence of additional reactants to produce a pre-reformed hydrocarbon fuel having reduced amounts of higher hydrocarbons;
removing the pre-reformed hydrocarbon fuel from the duct via the outlet;
removing particulate carbon from the pre-reformed hydrocarbon fuel and supplying the pre-reformed hydrocarbon fuel to a reformer in communication with a fuel cell.
2. A method according to claim 1 , wherein the hydrocarbon fuel is natural gas.