Table 11.
Reaction of Nitric Oxide with Hydrogen
Presence of hydrogen increases r a t e of NO removal
Space Velocity,
Temp., O
c.
Volume yo in Exit Gas GO2
co
Hr.-1
NO
% No Removal
0,093 0.097 0.046 0.037 0.029 0.000 0.000 0.013
55.0 55.4b 78.8 83.0 86.6 100.0 100.0 93.9
0.046 0.0
71.0 100.0
0.322 0.052
50.5 92.3
0.03 0* 003
84.7 100.0
Carbon C, Gas Mixture B 485Q 485” 545 545 545 595” 595 595
1650 1570 1840 1570 1430 1940 2550 3170
540a 625
1490 1620
540a 625
1585 1580
540 595
1460 1430
literature Cited
0.009 0.010 0.007 0.007 0.007 0 * 008 0.011 0.008
Carbon C, Gas Mixture C 0 0
0.006 0.016
Carbon C, Gas Mixture A 0.014
(1) Andrusov, L., Ber. 60, 536 (1927). (2) Haagen-Smit, A. J., Bradley, C. E., Fox, M. M., IND. END. CHEM. 45,2086 (1953). (3) Leighton, P. A,, Perkins, W. A , , Air Pollution Found. Refit. No. 14, (March 1956). (4) Madely, D. G., Strickland-Constable, R. F., Trans. Faraday SOC. 4 9 , 1312 (1953’1. RLnze&, N. A., Romanovsky, J. C., (5) J . Air. Pollution, Control Assoc. 6 , 154 (1956). Riese, W., Brennstoff-Chem. 20, 301 , _ ^ ^ ^ I
0.047 0.079
0.047
higher space velocities. Such a process would be practical only in a n industrial installation where the heat value of the natural gas consumed could be recovered.
(lY5Y).
Carbon B, Gas Mixture B
... ...
0.013 0.022
(10)
Carbon A, Gas Mixture B 425 485 545
... ...
1580 1540 1620
0.113 0.062 0.000
A
B C Average values.
71.3 100.0
N2
H 2
KO
98.62 98.88 99.14
0.70 0.90 0.70
0.68 0.22 0.16
* Gas saturated with water at room temperature. Table Ill.
Space Velocity,
Hr.
Hr.-I
coz
1490 1490 1480 1700 1700 1600
0.008 0.010 0.010 0.009 0,009 0.008
molecules of nitric oxide (or N202) and carbon. Termolecular collisions involving nitric oxide and chlorine, bromine, oxygen, a n d hydrogen have been described ( 3 ) . T h e present work is a preliminary investigation and as such was not designed to give information on the exact mechanism. Any attempts to assign a mechanism o n the basis of these experiments would be presumptuous. Interpretation of over-all results from experiments such as these must proceed with caution, especially when attempting to predict the results in a complex system such as is found in a n exhaust gas. The equilibrium existing at the surface of the carbon may be sensitive to the presence of the other exhaust constituents. Further work is needed to
0.017 0.046 0.088 0.093 0.093 0.093
(13) (14)
RECEIVED for review August 15, 1957 A C C ~ P T EJanuary D 29, 1958
%so Removal 92.1 78.8 59.4 56.8 55.0 55.0
establish the effect of these other substances. A major problem i n attempting to use activated carbon for removing nitric oxide from exhaust gases is the fact that most of these gases contain oxygen. T h e oxygen will readily oxidize the carbon a t 600’ C.; therrfore, some means of oxygen removal must be provided. O n e method in industrial use is to inject natural gas into the exhaust and use u p the oxygen by combustion. This reaction, if carried out under the proper conditions, will produce hydrogen a t the same time. This scheme would be beneficial in two ways: (1) Hydrogen would be produced to aid the speed of reaction and decrease consumption of carbon, and (2) the temperature of the gas would be raised, allowing
INDUSTRIAL AND ENGINEERING CHEMISTRY
(12)
Temperature, 485’ C.)
Volume % in Exit Gas NO
Time,
(11)
Divisions of Industrial and Engineering and Water, Sewage, and Sanitation Chemistry, Symposium on Air Pollution, 132nd Meeting, ACS, New York, PI’. Y . , September 1957.
Activity Decreases with Time
(Feed gas composition,1701. %, Kz, 99.88; Hz,0.90; NO, 0.22.
1 168
47.8
Feed Gas Composition, Val. %
Gas Mixture
a
0.032 0.032 0.020
I . .
(9)
Zbid., 25, 25 (1940). Riesz, C. H., Morritz, F. L., Franson, K. D., Air Pollution Found. Refit. No. 20 (May 1957). Shah. M. S.. J . Chem. SOC.1929. 2661. 2676.’ Shapleigh, J. H., U. S. Patent 2,381,699 (Aug. 7, 1945). Smith, R. N., Lesnini, D., Mooi, J., J.Phys. Chem. 60, 1063 (1956). Zbid., 61,81 (1957). Strickland-Constable, R. F., Trans. 34, 1374 (1938). Faraday SOC. Usachev, P. V., Ilinskaya, 0. V., Russian Patent 53,543 (July 31, 1938).
CORRECTION Engineering Design on a Computer I n the article on “Engineering Design on a Computer” by E. J. Higgins, J. W. Kellett, and L . T. U n g [IND.ENG. CHEM.50, 712 (1958)], the following corrections should be made: O n page 726, in the box on Furnace Coil Procedure, this heading and statement should follow the third item or listing: CALCULATE Outlet conversion by rrial and error. O n page 717, Table I, item 6, the second portion of the second line should read : If the shell side resistance is less than O n page 718, the title of the first box should be : How the Cost Estimation Program Operates
