Find the estimated emissions listed below for an uncontrolled $($Post$-$NSPS$)$ large wall$-$fired

boiler natural gas cogeneration facility that burns $500$ million standard cubic feet $($scf$)$ of

natural gas per year. Use the EPA$$s AP$-42($Volume $1,5$th ed$.)$ Chapter $1$: External Combustion

Sources Emission Factors for Natural Gas Combustion. $($use $1$ ton $=2000$ lbs$)$

a$.$ Tons of NOx emitted per year

b$.$ Tons of CO emitted per year

c$.$ Tons of CO$2$ emitted per year

d$.$ Are these values for emissions reliable? Why?