BS EN 15984-2022 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.
This document defines a gas chromatographic analysis for the determination of the composition of fuel gases, as used in refinery heating gas. These results are used to calculate the carbon content and the lower calorific value.
With this gas chromatographic analysis, an overall of 23 refinery heating gas components are determined in concentrations as typically found in refineries (see Table 1 for further details).
Water is not analysed. The results represent dry gases.
NOTE 1 Depending on the equipment used, there is a possibility to determine higher hydrocarbons as well.
NOTE 2 For the purposes of this document, the terms “% (V/V)” is used to represent the volume fraction (φ).
IMPORTANT — This document does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this document to establish appropriate safety and health practices and determine the applicability of regulatory limitations.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
4 Principle
This document defines a procedure that is used to determine all components that are present in a typical refinery heating gas, as indicated in Table 1.
NOTE The composition range in which each component can be analyzed does depend on the actual sample composition as higher amounts of a certain component can affect the detection range of other components eluting close by. The general ranges which apply to all the individual components are:
— hydrocarbons from 0,01 (mol/100 mol) up to 100 (mol/100 mol);
— non-condensable gases from 0,02 (mol/100 mol) 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, r be integrated into one.
Depending on the configuration, hydrocarbons with more than five carbon atoms are reported as a sum parameter. The composition of the refinery heating gas is used to calculate the carbon content and the calorific value. A typical procedure is described hereafter. A configuration is acceptable when the determination results in the precision as described in Clause 11.
5 Reagents and materials
5.1 Gases.
5.1.1 Hydrogen, with a minimum purity of 99,995 % (V/V).
5.1.2 Helium, with a minimum purity of 99,995 % (V/V).
5.1.3 Nitrogen, with a minimum purity of 99,995 % (V/V).
5.1.4 Air, free of oil and water.
5.1.5 Argon, as alternative for analysis system 2, with a minimum purity of 99,995 % (V/V).
5.2 Calibration sample.
A certified reference gas mixture in concentrations that allow the determination of the necessary response factors (see 8.1) and retention times is required.
6 Apparatus
6.1 Usual laboratory apparatus and glassware.
6.2 Gas chromatographic apparatus, consisting of at least three separation systems able to work simultaneously in one gas chromatograph, with a Thermal Conductivity Detector (TCD) and Flame Ionization Detector (FID) that should be available, and confirming to the requirements as given in Clause 7.
7 Gas chromatographic analysis
7.1 Analysis systems
The gas chromatographic system, as recommended in Annex A, 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 sieve column and back flushed.
NOTE HayeSep © and Molsieve © are examples of such commercially available columns 1 .
Hydrogen is determined on a TCD with nitrogen (5.1.3) as the carrier gas (see Figure A.4).
2) Analysis system 2
The second analysis system separates non-condensable gases, carbon dioxide, and hydrocarbons with two carbon atoms and hydrogen sulfide with helium (5.1.2) as the carrier gas and a TCD as a detector. After a pre-separation on a porous polymer column (column 3) propane and higher hydrocarbons are back flushed and vented. See Figure A.5 for details.
When the inert gases (O 2 /Ar, N 2 , CH 4 and CO) are on the molecular sieve 13X column, this column is isolated. Carbon dioxide, the C 2 -hydrocarbons and hydrogen sulfide are eluted from the porous polymer column (column 4) and are detected. The C 2 -hydrocarbons from this fraction are not used for quantification. After this the 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 (5.1.1) or helium (5.1.2) as the carrier gas. Two columns are used in series. From the methyl silicone column (column 1), the components 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 Figure A.6 for details.BS EN 15984 pdf download.