BS EN 15984:2011 pdf free download Petroleum industry and products — Determination of composition of refinery heating gas and calculation of carbon content and calorific value — Gas chromatography method
1 Scope
This European Standard defines a gas chromatographic analysis for the determination of the composition offuel gases, as used in refinery heating gas.These results are used to calculate the carbon content and thelower calorific value.
With this gas chromatographic analysis, an overall of 23 refinery heating gas components are determined inconcentrations as typically found in refineries (see Table 1 for further details).
Water is not analysed.The results represent dry gases.
NOTE1 Depending on the equipment used, there is a possibility to determine higher hydrocarbons as well.
NOTE2 For the purposes of this European Standard, the terms “% (vV)” is used to represent the volume fraction (p).
IMPORTANT—This standard does not purport to address all of the safety problems associated withits use. lt is the responsibility of the user of this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limitations.
2Principle
This standard defines a procedure that is used to determine all components that are present in a typicalrefinery heating gas, as indicated in Table 1.
NOTE The composition range in which each component can be analyzed does depend on the actual samplecomposition as higher amounts of a certain component may affect the detection range of other components eluting closeby.The general ranges which apply to all the individual components are:;
Hydrocarbons from 0,01 (mol/1 00 mol) up to 100 (mol/1 00 mol);
Non-condensable gases from o,02(mol/100 moll up to 100(mol/100 mol);
For hydrogen sulfide a range between 0,1 (mol/100 mol) up to 10(mol/100 mol) has been found applicable.
Three different analysis systems are necessary; they may be built in three separate gas chromatographs, orbe integrated into one.
Depending on the configuration, hydrocarbons with more than five carbon atoms are reported as a sumparameter.The composition of the refinery heating gas is used to calculate the carbon content and thecalorific value. A typical procedure is described hereafter. A configuration is acceptable when thedetermination gives the precision as described in Clause 9.
3Reagents and materials
3.1Gases.
3.1.1 Hydrogen, with a minimum purity of 99,995 % (VV).
3.1.2 Helium, with a minimum purity of 99,995 % ( V/V).
3.1.3 Nitrogen, with a minimum purity of 99,995 % (V/V).
3.1.4 Air, free of oil and water.
3.1.5 Argon, as alternative for analysis system 2, with a minimum purity of 99,995 % (V/V).
5Gas chromatographic analysis
5.1Analysis systems
The gas chromatographic system consist of the following three parts:
1)Analysis system 1
All components except hydrogen (see Table 1) are retained on a porous polymer and a molecular sievecolumn and back flushed.
NOTE HayeSepo and Molsieveo are examples of such commercially available columns.
Hydrogen is determined on a TCD with nitrogen (3.1.3) as the carrier gas (see Figure A.4).
2Analysis system 2
The second analysis system separates non-condensable gases, carbon dioxide,and hydrocarbons with twocarbon atoms and hydrogen sulfide with helium (3.1.2) as the carrier gas and a TCD as a detector.After apre-separation on a porous polymer column (column 3) propane and higher hydrocarbons are back flushedand vented.See Figure A.5 for details..
When the inert gases (Oz/Ar,N. CH, and CO) are on the molecular sieve 13X column, this column is isolated.Carbon dioxide,the C-hydrocarbons and hydrogen sulfide are eluted from the porous polymer column(column 4) and are detected. The C2-hydrocarbons from this fraction are not used for quantification.After thisthe molecular sieve 13x column (column 6) is eluted and the components are determined on the TCD.Methane is quantified on Analysis System 3.
3)Analysis system 3
The third analysis system separates and quantifies all hydrocarbons by an FID and hydrogen (3.1.1) or helium(3.1.2) as the carrier gas. Two columns are used in series. From the methyl silicone column (column 1), thecomponents above a certain cut point e.g. n-pentane are back flushed and determined as a summed peak.The hydrocarbons from the alumina oxide column,column 2, are then separated and quantified.See FigureA.6 for details.
5.2System configuration
The gas chromatographic system may consist of one or more gas chromatographs, with the possibility forisothermal or temperature programmed runs or both depending on the selected system configuration.ATCDand an FID shall be available.
A gas flow control system and gas sampling valves and switching valves are used.Means for quantification shall be provided.
NOTEOptionally a vaporizer may be used.5.3Columns
A combination of packed and capillary columns is possible.
lt shall be ascertained that a quantitative separation of all the components that need to be determined (seeTable 1) is possible and that the summed total of Cp. is quantitative. Adequate separation is required betweenthe comoonents on all three sebaration svstems.