A team of Dutch students is working on a project to develop a green energy system that will use iron powder as the basic fuel to generate steam with the aim of creating a propulsion system using recyclable fuels writes Dag Pike.

A diagram of the iron combustion cycle

A diagram of the iron combustion cycle

Burning iron seems a most unlikely phenomenon but it is the form of iron that is used that makes it combustible. The students are using iron powder which is iron in a very fine form comparable to finely sifted flour. In the system being developed in Holland, the initial ignition of the iron powder is started by using a propane igniter but once the powder has been ignited it burns in a self-sustaining way at a temperature of around 850°C. The flame from the burning iron powder can then be used in a boiler to turn water into steam and that steam can then be used to drive a turbine for direct power or to drive a generator for electrical power with no emissions.

At the end of the process oxygen from the air has been added to the iron powder to form an iron oxide which is basically rust. It is then possible to convert that rust back to iron powder with the use of hydrogen which would combine with the oxygen to form water. Used in this way the iron powder becomes fully recyclable meaning that the iron powder burner is an energy storage system, taking energy in and producing energy outwards and more effective than say batteries or other current systems as a means of storing electricity. Because the conversion back to iron powder can be carried out away from the burning process this burning of iron powder can be particularly suitable for transport and the next step for the students is to develop a system that could work for boat propulsion.

In a boat system the iron powder would be loaded as the ‘fuel’ for the ship. It would be burned to create the steam with this steam then being used in a conventional way to drive a reciprocating engine or a turbine either with direct propulsion or via an electrical system. The waste product from the combustion, the rust, would then be off-loaded in port and fresh ‘fuel’ in the form of iron power loaded on board more or less like conventional refuelling leaving the ship emitting no harmful emissions.