Question 21Steam Plants - Assistant Engineer

The correct answer is C) more heat is liberated by the production of CO2 than CO. The reasoning behind this is that when burning fuel oil in a boiler, the goal is to achieve complete combustion, resulting in the formation of carbon dioxide (CO2) rather than carbon monoxide (CO). The production of CO2 releases more heat energy compared to the formation of CO, as the complete oxidation of carbon to CO2 is a more exothermic (heat-releasing) reaction. This higher heat liberation is desired for efficient boiler operation and maximum heat transfer to the working fluid. The other answer choices are incorrect because they either do not accurately describe the relationship between CO2 and heat liberation (A and D) or they do not address the primary reason for the high CO2 content in the stack gas (B).