E3.8 Corrected Concentrations

Example 3.8: Current hazardous waste regulations require that emissions be corrected to 7% oxygen in the stack on a dry basis. The CO concentration from the hazardous waste incinerator is measured at 20 ppm at a temperature of 175 °F. The O₂ concentration in the stack is measured to 12% by volume on wet basis. In another test the particulate concentration in the stack is measured at 25 mg/dscf at a stack oxygen concentration of 12% measured on a dry basis. Molar content of water in the stack gas is 10%. What is the corrected CO content in the stack gas? What is the corrected particulate concentration?

Solution

Test 1:

Oxygen concentration in the stack gases, O₂ = 12% on wet basis

Water content of the stack gases, H₂O = 10%,

Nitrogen content of the stack gases on wet basis, N₂ = 78%

Carbon monoxide concentration, P_m = 20 ppm

Oxygen concentration in the stack gases on dry basis, Y = 12/(100 - 10) = 13.33%

Corrected concentration, P_c = P_m(14)/(21 - Y) = 20(14)/(21 - 13.33) = 36.52 ppm

Test 2:

Particulate concentration, P_m = 25 mg/dscf

Oxygen concentration in the stack gases on dry basis, O₂ = 12%

Corrected concentration, P_c = 25(14)/(21 - 12) = 38.89 mg/dscf