Good points. I would note that iron production will continue to require fossil fuels for the foreseeable future. Most iron ores are iron oxides. In order to free the iron you need to add carbon from fossil fuels to fuse with the oxygen atoms. The by product is carbon dioxide and iron. This can be done in the DRI process using NG or coal gas or in blast furnaces that can use NG or coal.
Honorable Sir,
I have visited quite a few steel mills & blast furnaces over the years. As I understand, the reduction process of iron ore from iron oxides to metallic iron requires ‘Carbon’. This can be in the form of coke, anthracite (naturally occurring smokeless coal) or charcoal.
The chemical; reactions taking place in blast furnace are:
C + O2 ==>>
CO2
CO2 + C ==>> 2CO
Fe2O3 + 3CO ==>> 2Fe + 3CO2
Since iron ore is always contaminated with sandy impurities (Silicon Oxide). Limestone (calcium oxide) is always added to the ore as ‘Flux’ which reacts as:
CaO + SiO2 ==>> CaSiO3
Molten iron sets at the bottom forming ‘Pig Iron’ and Calcium Silicate floats at the top and removed as ‘Slag’. I had heard the use of ‘Syngas’ from coal mixed with pulverized charcoal to reduce
CO2, &
CO emissions. Since natural gas is methane with no carbon monoxide, I would have thought that natural gas as it is would not work. Syngas is made from coal therefore it has a large component of carbon monoxide.
What I had read about DRI (Directly Reduced Iron) process using natural gas was that it is a two-stage process. The first stage being the ‘Catalytic Steam Reforming' of natural gas where the following chemical reaction takes place:
CH4 + H2O → CO +3H2
The reformed gas is mixed with crushed limestone which then reduces the iron ore (Midrex process). However, technology has moved on since I last visited any steel mill (about 15 years ago). Since one never stops learning and you are obviously knowledgeable about the DRI process; is there any modified DRI process that can reduce iron ore without the natural gas being reformed first?