5 ppm it is noted that the ratio of moles of no and so 3 is 2 73 methanol is injected into an effluent stream having the same composition as that illustrated in example 5 except that the initial concentration of methanol is reduced to 150 ppm it is found under these conditions that so 3 concentration is reduced to 0 016 ppm and the co concentration is only 53 7 ppm in this example the ratio of the concentration of ch 3 oh to the sum of the concentrations of so 3 and no is 1 36 this example along with example 5 illustrate that the use ratio of moles of ch 3 oh to the sum of moles of no plus so 3 in the range 0 8 to 2 0 is sufficient to reduce so 3 efficiently without causing larger than necessary emissions of co to the atmosphere methanol is injected into an effluent stream pressure is held at approximately 1 atmosphere and a constant temperature of 950 u00b0 c is maintained the reaction time is 0 3 seconds the composition of the effluent stream including methanol is as follows ______________________________________component concentration______________________________________nh sub 3 5 ppmso sub 3 10 ppmso sub 2 500 ppmno 100 ppmch sub 3 oh 150 ppmo sub 2 3 co sub 2 10 h sub 2 o 14 n sub 2 balance______________________________________ following this reaction the temperature is abruptly decreased until no further reaction occurs in this example it is found that so 3 concentration increases from 10 ppm to 12 3 ppm with corresponding nh 4 hso 4 formation co concentration is 3 6 ppm this is due to reaction temperatures in excess of 900 u00b0 c coupled with a reaction time in excess of 0.