Question 4 - The carbon footprint (5 out of 20 points) Calculate the minimum carbon footprint of an atmospheric ironmaking blast furnace assuming it processes 42,500 tons of hematite (Fe203) per year to produce liquid Fe at 1900 K. Precursors are pre-heated and fed to the reactor at room temperature (1200 K). Heat is provided to the reactor by burning natural gas*. *See https://www.engineeringtoolbox.com/co2-emission-fuels-d 1085.html for the specific COz emissions per unit of heat produced for various fuels