QUESTION $2$B: Write short notes on the following terms a$)$ Compressed natural gas $($CNG$),$ b$)$ Steady flow process $($SFP$),$ c$)$ Higher calorific value $($HCV$),$ and d$)$ Lower calorific value $($LCV$).$ Calculate the e$)$ HCV and f$)$ LCV of coals having the following compositions $-85\%$ carbon, $8\%$ hydrogen, $1\%$ Sulphur, $2\%$ nitrogen, and $4\%$ ash. $[$Latent heat of steam is $587ca\frac{l}{g}].$

$[$Marks $6]$

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c$)$ Higher calorific value $($HCV$)$

d$)$ Lower calorific value $($LCV$)$

e$)HCV$ of coal: $,HCV=\frac{1}{100}[8,080\%C+34,500(\%H-\%\frac{0}{8})+2,240\%K]kca\frac{l}{k}g$

$$ LCV of coal: $LCV=[HCV-9\%\frac{H}{100}587]kca\frac{l}{k}g$