Question

A stack gas flowing at 80 m^3/min (at T = 25 degree C and 1 atm) contains approximately 75% N2, 5% O2, 8% H2O, and 12% CO2.

a) Calculate the gas molecular weight.

b) The gas contains 650 ppm SO2; calculate the emission rate of SO2 in kg/day.

please show your work in steps specially for part b

Answer 1

if this is given by volume, then mole % is equal to volume (avogrados)

assume a basis of V = 80 m3 per min

now...

MW = mol fraction of i * MW of i....

MW = (0.75*28) + (0.05*32) + (0.08*18)+ (0.12*44)

MW = 29.32 g/mol for the gas

b)

650 ppm of SO2 --> 650 mg / L = 0.65 g / L

0.65 g of SO2 / L

Total V in 1 day = 80 m3/min * 60 min/h * 60 h /day = 288000 m3/day

change to L = 288000*10^3 L/day

mass of SO2 = 0.650*(288000*10^3) = 187200000 g /day = 187200 kg/day of SO2