HIGH TEMPERATURE CARBONIZATION OF COAL 417
prevailing, and under old-fashioned conditions of seal and vacuum, so that at the present day it would be unlikely that the nitrogen conient would. remain practically constant, and even show the reduction which Wright found after five and a half hours. In faet, in connection with the heavy twelve-hour charge the author, in an experiment carried out some five years ago, finds that with a |-inch seal and U-inch. “ draw ” the composition approximates to the following :—
Hydrogen
Methane
Heavy hydrocarbons
Carbon monoxide.
Carbon dioxide
Nitrogen
After 6 hours. 45-2 per cent. 22-9
4-1
6'3
2-6
18-0
After 12 hours.
65-8 per cent.
1-4
nil
15-2
0-6
16-6
So far as nitrogen only is concerned (determined by the direct metliod) the following figures are given as typical of those obtained under the rather severe and abnormal conditions quoted above :—
After 1 hour 11-6 per cent. . 14-8 . 16-4 . 16-7 . 17-5 . 18-5 . 19-7 . 20-1 of nitrogen. 99 99 99 99 99 99 99
„ 2 „ 3 „ 4 „ 5 „ 6 „ 7 „ 8 hours 99 ... >> • • • • 99 ... • • •
,, 9 99 ... . 20-2 99
„ 10 99 ... . 15-9 99
„ 11 ... . 15-2 ..
„ 12 99 ... . 15-2 99
In the modem form of coke oven it is customary to carbonize the heavy charges, amounting in some cases to as mueh as 10 tons, for periods of twenty-four hours, or even longer. Under such conditions the deterioration becomes somewhat excessive towards the end of the period, as is shown by the following results, obtained by Simmersbach for a twenty-nine hour charge.
Hour of car-bonization. 2 3 4 5 6 7 8 9 10 11 12 1.3 15 17 19 21 23 25 27
Gas analysis. CO2 3-3 3-0 2-3 2-5 9.9 2-0 1-4 1-9 2-3 1-3 1-5 2-0 1-9 1-8 1-1 1-05 0-8 0-7 1-0'
C6He 1-8 1*5 1-1 1-1 1-0 0-8 0-6 0-5 0-35 0-35 0-35 0-3 0-25 0-1 — — — — —
C2H4 4-0 3-5 3-1 3-2 2-8 2-5 2-5 2-0 1-75 2-05 1-85 1-8 1-8 1-9 1-2 1-0 0-6 0-3 o-a
02 1-05 0-8 0-6 0-6 0-5 0-5 0-2 0-2 0-2 0-1 0-2 0-2 0-15 0-25 0-15 0-05 0-05 0-1 o-s
CO 0-9 1-9 2-9 2-8 3-0 3-95 3-4 3-1 2-8 2-8 4-15 4-1 3-9 4-15 4-7 4-0 3-8 4-9 5-8
ch4 36-65 36-1 34-5 34-5 33-6 32-4 35-65 33-45 31-2 32-4 33-4 32-45 33-2 30-6 26-1 21-15 18-95 12-2 4-7
h2 42-5 44-6 48-8 47-8 50-1 50-75 53-65 50-55 47-1 51*5 50-65 49-75 53-4 51-6 55-75 58-95 61-9 67-0 70-0
n2 10-0 8*6 6-7 7-5 6-8 7-1 3-6 8-3 14-3 9-5 7-9 9-4 5-4 8-6 11-0 13-8 13-9 14-8 17-9
—
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