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THE COAL TRADE BULLETIN. 27
SOME CALORIMETRIC DETERMINATIONS OF KENTUCKY COALS*
By Alfred M. Peter. Chief Chemist Agricultural Experiment Station.
Kentucky State University. Lexington. Ky.
During the years when the Kentucky Geological
survey was being conducted under the able and
efficient directorship of Charles J. Norwood, with
headquarters at State University, a number of
calorimeter determinations were made upon samples
of coal obtained from different mines in tlie
state. For this work Prof. Norwood provided,
first a Parr fuel calorimeter and later one of the
Emerson design, the latter being a new form of
the bomb type of calorimeter and capable of giving
results as accurate as those obtainable with the
otlier standard instruments of this type, but much
easier to manipulate and more rapid in action.
The determinations were made at different times
by Prof. Norwood's assistants, Messrs. Quickel, Mc-
Hargue and Calloway. Some of these results have
been published in the report of progress of tbe
survey for the years 1908 and 1909; some are to
be found in tbe bulletins of the survey, part of
which, however, are still in the hands of the public
printer, and I believe some have never been published.
I intend to take only a few of the determinations,
those which are most representative of the
more important coal beds in the state, and I shall
endeavor to ascertain whether that part of the
coal which is both volatile and combustible is of
equal heating value in all the coals presented, considering,.of
course, tlie quantity of such matter in
the eoal.
Where coal has a large amount of volatile combustible
matter, we naturally expect it to have a
high heating value because of the large amount of
hydrocarbons which are contained in such matter.
Hydrogen, on burning, produces 62,001) B.t.u. per
pound, whereas carbon develops only 14,500 B.t.u.,
ancl for this reason we would expect matter containing
hydrocarbons to give more heat than fixed
carbon when burned.
On the other band, volatile combustible mattei
contains more or less oxygen, and its presence indicates
that the coal is more or less an oxidized
product and, therefore, less capable of giving out
all the heat which a
COMPLETELY UNOXIDIZED BODY
would emit on burning. Moreover, in this volatile
combustible part of coal, sulphur and nitrogen
are included, the former having a low heat
value, about 4000 B.t.u. per pound when burning,
and the latter oxidizing with the emission of but
little heat. In the incombustible volatile matter,
'Paper read at the Kentucky Mining Institute. Kentucky
State University. Lexington. Ky.
more or less water is found. This is derived from
the clay which forms after burning a part of the
ash constituent. Thus, if the volatile matter has
a varying composition, it may have a variant ability
to emit heat when burned.
I propose to estimate the heat in this volatile
part of tbe eoal by deducting the heat generated
by burning fixed carbon or coke from that which
is obtained when the original sample is burned.
This deduction for the heat of the fixed carbon
will not be taken from coke prepared in the laboratory,
nor from the same sample of coal of which
the heat of combustion is determined but will be
derived as an average from 7 commercial cokes
made from coal mined in Kentucky and consumed
in a Parr calorimeter.
Had this investigation been kept in view at the
time the survey made the tests on Kentucky coais,
the goal would have been more certainly attained
by actually determining tbe heat of combustion
of the coke from a sample of coal which was a
duplicate of the luel tested in the calorimeter.
Average analysis and heat of combustion of 7 commercial
cokes from Kentucky coal.
.Moisture 0.77 0.02 0.35
Volatile combustible matter 1.6-2 0.19 0.89
Fixed carbon 90.61 79.23 84.63
Ash 19.16 9.07 14.13
Total 100.00
Sulphur 2.01 0.45 1.01
B.t.u. per lb. of coke 12,717 10,283 11.703
Total combustible matter—
( 100 — moisture — ash) 85.52
B.t.u. per lb. of same 14.491 12.S42 13,684
From this table it appears that the average heat
value of the combustible matter in these samples
of coke was 13,680 B.t.u. per pound, and. in the
absence of better data. I propose to use this figure
in the calculations which are to follow.
The range of variation in the analysis of these
samples and in their heat values as thus determined,
is quite large and the figure for the average
beat, value is considerably lower than that usually
accepted for carbon. There are, however, certain
reasons why tbe heating value of the combustible
matter in coke should not be as great as that of
pure carbon. Coke always
CONTAINS MORE OK LESS
sulphur as well as small percentages of nitrogen
any hydrogen.
Hydrogen, of course, would tend to bring up the
value a little, whereas, sulphur and nitrogen would
reduce it. Besides this, according to the statements
of the textbooks. Favre and Silbermann,
whose work was published in 1852, declare that the