Which fuel needs to be at proper temperature and pressure for complete combustion?

Which fuel needs to be at proper temperature and pressure for complete combustion?

• A. Coal
• B. Propane
• C. No. 6 Oil
• D. Natural gas

Answer: (C)

Complete combustion relies on the fuel being properly atomized and mixed with air in the flame. For liquid fuels, that atomization depends on getting the fuel to the right temperature and delivering it at the correct pressure so the spray is fine and can evenly mix with the air. No.6 fuel oil is a heavy, viscous liquid, so it must be heated and pumped at the proper pressure to spray correctly. If the fuel is too cold or the pressure is off, droplets are too large, the air-fuel mix is poor, and combustion becomes incomplete, producing smoke and carbon monoxide. Gaseous fuels like natural gas and propane already vaporize readily and are designed to mix with air at the burner, so they don’t rely on heating the fuel to achieve complete combustion. Coal is a solid and burns through a different process, not in the same way that heating and pressurizing a liquid fuel enables clean, complete combustion.

Complete combustion relies on the fuel being properly atomized and mixed with air in the flame. For liquid fuels, that atomization depends on getting the fuel to the right temperature and delivering it at the correct pressure so the spray is fine and can evenly mix with the air. No.6 fuel oil is a heavy, viscous liquid, so it must be heated and pumped at the proper pressure to spray correctly. If the fuel is too cold or the pressure is off, droplets are too large, the air-fuel mix is poor, and combustion becomes incomplete, producing smoke and carbon monoxide. Gaseous fuels like natural gas and propane already vaporize readily and are designed to mix with air at the burner, so they don’t rely on heating the fuel to achieve complete combustion. Coal is a solid and burns through a different process, not in the same way that heating and pressurizing a liquid fuel enables clean, complete combustion.