Several patents exist for induction iron smelting including: US2729556, US4464197, and US7413590. These patents all describe induction heating of iron ore with a carbon material, usually coal, to act as the reducing agent to produce metallic iron.
The advantages of my idea over these prior methods include:
1. Local electric generation by methane turbine improves reliability by eliminating the need for an external electrical energy supply to supply the induction furnace and electric controls.
2. Local electric generation with heat recovery for refractory vessel preheating from exhaust gas improves the efficiency.
3. Use of methane gas for both local electrical generation and for iron reduction in the refractory vessel eliminates the need for handling and burning of coal on site, and eliminates the coal ash waste product.
4. Local generation of electricity eliminates transmission losses and reduces utility costs and interconnection fees.
5. Lack of coal burning means that the flue gas is much cleaner, which means that it can be collected and recycled through the refractory chamber to insure complete oxidation of the methane.
6. Local electric power generation by natural gas turbine permits operating the generator as a peaking plant to sell power to the electric grid when the refractory chamber is not in use for maintenance or repairs, or because it is more profitable to sell electric power such as during peak hours.
7. Use of methane as a reducing agent rather than the carbon monoxide normally produced by burning coal is much more efficient. Each molecule of methane can accept up to four oxygen atoms from iron oxide (ultimate attainable end products are CO2 and 2 H2O), while carbon monoxide can only accept one.
