BS ISO 647:2017 pdf download – Brown coals and Ii gnites Determination of the yields of tar , water , gas and coke residue by low temperature distillation
1 Scope
This document specifies a method for the determination of the yields of tar, water, gas and coke residueobtained from brown coal and lignite by distillation to a final temperature of 520 °℃.
2Normative references
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references, only the edition cited applies. Forundated references, the latest edition of the referenced document (including any amendments) applies.ISO 5068-2, Brown coals and lignites —Determination of moisture content —Part 2: Indirect gravimetricmethod for moisture in the analysis sample
ISO 1170, Coal and coke -Calculation of analyses to different bases
3Terms and definitions
No terms and definitions are listed in this document.
ISO and lEC maintain terminological databases for use in standardization at the following addresses:
—IEC Electropedia: available at http://www.electropedia.orgl
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The sample is heated in an aluminium retort to a temperature of 520 C during a period of 80 min.The products of decomposition pass into a water-cooled receiver. The tar and water are condensedwhile gaseous products pass to atmosphere. The coke residue remaining in the retort is weighed.Thereceiver and its contents are also weighed and the mass of the water in it determined by entrainmentwith 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 decompositionof the coal. A separate determination of moisture in the coal is made so that the decomposition watercan be calculated.
The percentage of gas (plus errors) is obtained by subtracting from 100 the sum of the percentages of cokeresidue, tar and total water.The results are reported on the “as analysed”” basis and on the “dry” basis.
5.1Graphite paste.
Ground dry and made into suitable paste with water or thick lubricating oil.
5.2 Xylene.
Boiling point 135 °C to 140°C.
5.3 Toluene.
Boiling point 110 °C.
6Apparatus6.1 Retort.
Made of aluminium, with the dimensions shown in Figure 1. With the cover fitted,its capacity with theoutlet tube shall be 170 ml ± 10 ml.The outlet tube shall be made of brass and its internal wall shall beclean and polished.A new assembly shall be heated at 520 °C for 20 min before use.
lf, through wear, the upper edge of the conical portion of the cover is below the top surface of the retort,its free volume will be less than 160 ml and a new cover is required. The new oversize cover shall beground so that when fitted, the upper edge of the round portion is less than 7 mm above the top surfaceof the retort. This will ensure that the free volume of the retort does not exceed 180 ml.
6. 3 Thermocouple a nd m iU ivoltmeter or nitro g en-filled mercury thermometer. Calibrated and capable of indicating temperatures up to 550 oc. A new thermometer sha Il be aged and then calibrated before use and shall be rechecked at intervals of one mon th by comparíng ít wi th a st andard thermometer in a manner approved by a national testing authority.
6.4 Receive r. Round-bottomed glass flask , capacity 750 ml , wi th conical ground joint and with either long or short neck dependíog 00 the method of connection to the retort (see provided wíth a rubber or glass stopper.
6.5 Cooling bath ,
BS ISO 647:2017
ISO 647:2017(E)
The distance between the receiver and the wa l1 s of the ba th is not less than 20 mm. The water flow shall be adjusted to maintain a temperature ofbetween 10 oC and 15 oC in the bath.BS ISO 647 pdf download.