1. The problem statement, all variables and given/known data A fuel gas consists of 75% butane (C4H10), 10% propane (C3H8) and 15% butene (C4H8) by volume. It is to be fed to the combustion chamber in 10% excess air at 25°C, where it is completely burnt to carbon dioxide and water. The flue gases produced are to be used to generate 5 bar steam from water at 90°C. If 5% of the heat available for steam production is lost to the atmosphere, determine the amount of steam raised per hour when the total flow of flue gases is 1400 kmol h–1. 2. Relevant equations 3. The attempt at a solution Cp(mean) = (Cp x T2) - (Cp1 x T1) / T2 - T1 = (2.934 x 2000) - (1.89 x 90) / 2000 - 90 = 2.98kJ/kG K then ....... delta (T) x Cp(mean) x Q x 0.95 = (198790) x 2.98 x 1400 x 0.95 = 7518579kJ/hr https://www.physicsforums.com/file:///page9image15296 [Broken] https://www.physicsforums.com/file:///page9image15456 [Broken] latent heat of evaporation @ 90°C = 2282 kJ / kg k so.... 7518579 / 2282 = 3295kmol/hr I have been told that my answer is incorrect. any help to see where i have gone wrong is appreciated. thanks.