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I was wondering if you could kindly help me in one of the question. its a tiny question..

the question is

1. 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 25ºC, 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 90ºC

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 gsaes is 1400 kmol /h

Data: Net calorific value (MJ m–3) at 25ºC of: Butane (C4H10) = 111.7 MJ m–3 Butene (C4H8) = 105.2 MJ m–3 Propane (C3H8) = 85.8 MJ m–3 Air is 21% oxygen, 79% nitrogen by volume and 23.3% oxygen and 76.7% nitrogen by mass. Atomic mass of C = 12, O = 16, N=14 and H = 1.

now the solution i'm meant to do is :

find the total heat required to heat water and we do it in three steps

1. find the sensible heat 90-100C --- the equation is m x cp x (temp difference) im not sure what tthe flow rate is and is the water m,cp ?

2. Latent heat - 100-152C

3.Sensible heat- not sure the temp difference

then we add all them to find the total and then 5% is lost so total heat/ 0.95 to find the heat supplied and at the end we are meant to divide the mass available by heat required.

does my method seems alright?

i will be highly glad if you could kindly help me in this.