A boiler burns natural gas $($consider that it is pure methane$)$ and consumes $10$ m$3/$h

expressed at normal conditions $(25\backslash$deg C$,1$ atm$).$

Assuming that $10\%$ by volume of excess oxygen is fed $($equivalent to molar excess$)$ and if the gas coming out of the boiler chimney is at $150\backslash$deg C and the fed water is at $60\backslash$deg C$,$ how many kg$/$h of saturated steam at $35$ psia are generated?