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IS0
I N T ERN AT1 O N A L ORGAN I Z AT I O N FOR STAND AR D I ZATl O N
IS0 RECOMMENDATION
R 647
DETERMINATION OF THE YIELDS OF TAR, WATER, GAS
AND COKE RESIDUE BY LOW TEMPERATURE DISTILLATION
OF BROWN COAL AND LIGNITE
1st EDITION
February 1968
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For each individual country the only valid standard is the national standard of that country.
Printed in Switzerland
Also issued in French and Russian. Copies to be obtained through the national standards organizations.
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BRIEF HISTORY
The IS0 Recommendation R 647, Determination of the yields of tar, water, gas and coke
residue by low temperature distillation of brown coal and lignite, was drawn up by Technical
Committee ISO/TC 27, Solid mineral fuels, the Secretariat of which is held by the British
Standards Institution (BSI).
Work on this question by the Technical Committee began in 1955 and led, in 1964, to the
adoption of a Draft IS0 Recommendation.
In November 1965, this Draft IS0 Recommendation (No. 865) was circulated to all the IS0
Member Bodies for enquiry. It was approved, subject to a few modifications of an editorial
nature, by the following Member Bodies:
Argentina Germany
Romania
Australia India
Spain
Austria Ireland Sweden
Belgium Italy Switzerland
Brazil Japan Turkey
Canada Korea, Rep. of U.A.R.
Chile Netherlands
United Kingdom
Czechoslovakia New Zealand
U.S.S.R.
Denmark Poland Yugoslavia
France Portugal
No Member Body opposed the approval of the Draft.
The Draft IS0 Recommendation was then submitted by correspondence to the IS0
Council, which decided, in February 1968, to accept it as an IS0 RECOMMENDATION.
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lSO/R 647 - 1968 (E)
IS0 Recommendation R 647 February 1968
DETERMINATION OF THE YIELDS OF TAR, WATER, GAS
AND COKE RESIDUE BY LOW TEMPERATURE DISTILLATION
OF BROWN COAL AND LIGNITE
INTRODUCTION
The yield of the distillation products by low temperature distillation, especially the yield of tar,
forms the basis for the classification of brown coal and lignite for use in low temperature car-
bonization.
1. SCOPE
This IS0 Recommendation describes a method for the determination of the yields of tar, water,
gas and coke residue obtained from brown coal and lignite by distillation to a final temperature
520 OC.
of
2. PRINCIPLE
The sample is heated in an aluminium retort to a temperature of 520 OC during a period of
80 minutes. The products of decomposition pass into a water-cooled receiver; the tar and water
are condensed while gaseous products pass to atmosphere. The coke residue remaining in the
retort is weighed. The receiver and its contents are also weighed and the mass of the water in
it determined by entrainment with toluene or xylene: the mass of tar is obtained by difference.
The total water in the receiver includes the moisture in the coal as well as that from the decompo-
sition of the coal. A separate determination of moisture in the coal, also by entrainment with
so that the decomposition water can be calculated.
toluene or xylene, is made
100 the sum of the percentages
The percentage of gas (plus errors) is obtained by subtracting from
of coke residue, of tar and of decomposition water. The results are reported on the “as analysed”
and on the “dry” basis.
3. REAGENTS
3.1 Graphite paste. Ground dry and made into a suitable paste with water or thick lubricating
oil.
Xylene, boiling point 135 to 140 “C or
3.2
Toluene, boiling point 110 OC.
4. APPARATUS
4.1 Retort, of aluminium, with the dimensions shown in Figure 1 ; with the cover fitted, its
capacity with the outlet tube is 170 f 10 cm3; the outlet tube is made of brass and its internal
wall is clean and polished. A new assembly should be heated at 520 OC for 20 minutes
before use.
4.2 Furnace, heated either electrically or by gas. For electrical heating, a resistance wire
furnace or a silicon carbide rod furnace may be used.
Thermocouple and millivoltmeter, or a nitrogen-filled mercury thermometer, calibrated
4.3
and capable of indicating the temperatures up to 550 OC.
NOTE. - A new thermometer should be aged and then calibrated before use and should be rechecked at
intervals of one month by comparing it with a standard thermometer in a manner approved by a national
testing authority.
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ISO/R 647 - 1968 (E)
Receiver. Round bottomed glass flask of 750 ml capacity, with conical ground joint
4.4
and with either long or short neck depending on the method of connection to the retort
(see Fig. 2), provided with a rubber or glass stopper.
4.5 Cooling bath. Water bath such that the distance between the receiver and the walls of the
bath is not less than 2 cm. The water flow is adjusted to maintain a temperature of be-
tween 10 and 15 "C in the bath.
4.6 Distillation apparatus. Suitable distillation apparatus for the determination of moisture
in brown coal or lignite, as specified in IS0 Recommendation R . . . ,* Determination of
moisture in brown coal and lignite.
5. PREPARATION OF TEST SAMPLE
Spread the laboratory sample on a tray and allow it to attain approximate moisture equilibrium
with the atmosphere. Carefully crush the sample so that at least 90% passes through a sieve
of 1 mm aperture whilst not more than 50% passes through a sieve of 0.2 mm aperture. If the
moisture content of the crushed sample is still greater than 20%, further air-drying should be
carried out to reduce the moisture content to between 10 and 20%. The test sample may be
stored in an hermetically sealed container. Alternatively, the sample may be kept for a period
not longer than one week in a stoppered container filled to more than 80% of its capacity.
NOTE. - When samples are kept for longer than one week in containers which are not hermetically sealed or are
not entirely filled, the loss of tar yield can be up to 0.5 % In certain cases the loss may be considerably greater.
6. PROCEDURE
Weigh, to the nearest 0.05 g, about 50 g of the test sample and transfer it completely to the retort.
Lightly smear the conical portion of the cover with the graphite paste, replace the cover and
seal by rotating it. Determine the moistu
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